Merge pull request #138 from github/erik-krogh/bump-this

bump the severity of `ql/implicit-this`

ql/src/queries/style/ImplicitThis.ql

@@ -2,8 +2,8 @@
  * @name Using implicit `this`
  * @description Writing member predicate calls with an implicit `this` can be confusing
  * @kind problem
- * @problem.severity recommendation
- * @precision very-high
+ * @problem.severity warning
+ * @precision high
  * @id ql/implicit-this
  * @tags maintainability
  */

repo-tests/codeql-go.txt

@@ -1 +1 @@
-4cae4b23fc1b2b1760e259b660996e9bb5573279
+894102defd0777931a0e261ad66e631e63ec0ad8

repo-tests/codeql-go/ql/lib/semmle/go/Decls.qll

@@ -137,7 +137,8 @@ class FuncDef extends @funcdef, StmtParent, ExprParent {
    */
   DataFlow::CallNode getACall() { result.getACallee() = this }
 
-  predicate isVariadic() { getType().isVariadic() }
+  /** Holds if this function is variadic. */
+  predicate isVariadic() { this.getType().isVariadic() }
 
   override string getAPrimaryQlClass() { result = "FuncDef" }
 }

repo-tests/codeql-go/ql/lib/semmle/go/Scopes.qll

@@ -377,10 +377,11 @@ class Function extends ValueEntity, @functionobject {
   /** Gets the declaration of this function, if any. */
   FuncDecl getFuncDecl() { none() }
 
+  /** Holds if this function is variadic. */
   predicate isVariadic() {
     this.(BuiltinFunction).getName() = ["append", "make", "print", "println"]
     or
-    this.(DeclaredFunction).getFuncDecl().isVariadic()
+    this.(DeclaredFunction).getType().(SignatureType).isVariadic()
   }
 
   /** Holds if this function has no observable side effects. */

repo-tests/codeql-go/ql/lib/semmle/go/dataflow/barrierguardutil/RegexpCheck.qll

@@ -4,22 +4,30 @@
 
 import go
 
+/**
+ * A call to a regexp match function, considered as a barrier guard for sanitizing untrusted URLs.
+ *
+ * This is overapproximate: we do not attempt to reason about the correctness of the regexp.
+ *
+ * Use this if you want to define a derived `DataFlow::BarrierGuard` without
+ * make the type recursive. Otherwise use `RegexpCheck`.
+ */
+predicate regexpFunctionChecksExpr(DataFlow::Node resultNode, Expr checked, boolean branch) {
+  exists(RegexpMatchFunction matchfn, DataFlow::CallNode call |
+    matchfn.getACall() = call and
+    resultNode = matchfn.getResult().getNode(call).getASuccessor*() and
+    checked = matchfn.getValue().getNode(call).asExpr() and
+    (branch = false or branch = true)
+  )
+}
+
 /**
  * A call to a regexp match function, considered as a barrier guard for sanitizing untrusted URLs.
  *
  * This is overapproximate: we do not attempt to reason about the correctness of the regexp.
  */
 class RegexpCheck extends DataFlow::BarrierGuard {
-  RegexpMatchFunction matchfn;
-  DataFlow::CallNode call;
+  RegexpCheck() { regexpFunctionChecksExpr(this, _, _) }
 
-  RegexpCheck() {
-    matchfn.getACall() = call and
-    this = matchfn.getResult().getNode(call).getASuccessor*()
-  }
-
-  override predicate checks(Expr e, boolean branch) {
-    e = matchfn.getValue().getNode(call).asExpr() and
-    (branch = false or branch = true)
-  }
+  override predicate checks(Expr e, boolean branch) { regexpFunctionChecksExpr(this, e, branch) }
 }

repo-tests/codeql-go/ql/lib/semmle/go/frameworks/Glog.qll

@@ -11,10 +11,17 @@ import go
  */
 module Glog {
   private class GlogCall extends LoggerCall::Range, DataFlow::CallNode {
+    int firstPrintedArg;
+
     GlogCall() {
-      exists(string pkg, Function f, string fn |
+      exists(string pkg, Function f, string fn, string level |
         pkg = package(["github.com/golang/glog", "gopkg.in/glog", "k8s.io/klog"], "") and
-        fn.regexpMatch("(Error|Exit|Fatal|Info|Warning)(|f|ln)") and
+        level = ["Error", "Exit", "Fatal", "Info", "Warning"] and
+        (
+          fn = level + ["", "f", "ln"] and firstPrintedArg = 0
+          or
+          fn = level + "Depth" and firstPrintedArg = 1
+        ) and
         this = f.getACall()
       |
         f.hasQualifiedName(pkg, fn)
@@ -23,6 +30,8 @@ module Glog {
       )
     }
 
-    override DataFlow::Node getAMessageComponent() { result = this.getAnArgument() }
+    override DataFlow::Node getAMessageComponent() {
+      result = this.getArgument(any(int i | i >= firstPrintedArg))
+    }
   }
 }

repo-tests/codeql-go/ql/lib/semmle/go/frameworks/Logrus.qll

@@ -11,7 +11,10 @@ module Logrus {
 
   bindingset[result]
   private string getALogResultName() {
-    result.matches(["Debug%", "Error%", "Fatal%", "Info%", "Panic%", "Print%", "Trace%", "Warn%"])
+    result
+        .matches([
+            "Debug%", "Error%", "Fatal%", "Info%", "Log%", "Panic%", "Print%", "Trace%", "Warn%"
+          ])
   }
 
   bindingset[result]
@@ -23,7 +26,7 @@ module Logrus {
     LogCall() {
       exists(string name | name = getALogResultName() or name = getAnEntryUpdatingMethodName() |
         this.getTarget().hasQualifiedName(packagePath(), name) or
-        this.getTarget().(Method).hasQualifiedName(packagePath(), "Entry", name)
+        this.getTarget().(Method).hasQualifiedName(packagePath(), ["Entry", "Logger"], name)
       )
     }
 

repo-tests/codeql-go/ql/lib/semmle/go/frameworks/SQL.qll

@@ -88,10 +88,11 @@ module SQL {
             // first argument to `squirrel.Expr`
             fn.hasQualifiedName(sq, "Expr")
             or
-            // first argument to the `Prefix` or `Suffix` method of one of the `*Builder` classes
+            // first argument to the `Prefix`, `Suffix` or `Where` method of one of the `*Builder` classes
             exists(string builder | builder.matches("%Builder") |
               fn.(Method).hasQualifiedName(sq, builder, "Prefix") or
-              fn.(Method).hasQualifiedName(sq, builder, "Suffix")
+              fn.(Method).hasQualifiedName(sq, builder, "Suffix") or
+              fn.(Method).hasQualifiedName(sq, builder, "Where")
             )
           ) and
           this = fn.getACall().getArgument(0) and

repo-tests/codeql-go/ql/lib/semmle/go/frameworks/stdlib/Log.qll

@@ -8,13 +8,7 @@ import go
 module Log {
   private class LogCall extends LoggerCall::Range, DataFlow::CallNode {
     LogCall() {
-      exists(string fn |
-        fn.matches("Fatal%")
-        or
-        fn.matches("Panic%")
-        or
-        fn.matches("Print%")
-      |
+      exists(string fn | fn.matches(["Fatal%", "Panic%", "Print%"]) |
         this.getTarget().hasQualifiedName("log", fn)
         or
         this.getTarget().(Method).hasQualifiedName("log", "Logger", fn)

repo-tests/codeql-go/ql/lib/semmle/go/security/IncorrectIntegerConversionLib.qll

@@ -124,7 +124,7 @@ class ConversionWithoutBoundsCheckConfig extends TaintTracking::Configuration {
     )
   }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, sinkBitSize) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, sinkBitSize) }
 
   override predicate isSanitizerGuard(DataFlow::BarrierGuard guard) {
     // To catch flows that only happen on 32-bit architectures we
@@ -136,7 +136,7 @@ class ConversionWithoutBoundsCheckConfig extends TaintTracking::Configuration {
 
   override predicate isSanitizerOut(DataFlow::Node node) {
     exists(int bitSize | isIncorrectIntegerConversion(sourceBitSize, bitSize) |
-      isSink(node, bitSize)
+      this.isSink(node, bitSize)
     )
   }
 }

repo-tests/codeql-go/ql/lib/semmle/go/security/LogInjection.qll

@@ -0,0 +1,33 @@
+/**
+ * Provides a taint tracking configuration for reasoning about log injection vulnerabilities.
+ *
+ * Note: for performance reasons, only import this file if `LogInjection::Configuration` is needed,
+ * otherwise `LogInjectionCustomizations` should be imported instead.
+ */
+
+import go
+
+/**
+ * Provides a taint-tracking configuration for reasoning about
+ * log injection vulnerabilities.
+ */
+module LogInjection {
+  import LogInjectionCustomizations::LogInjection
+
+  /**
+   * A taint-tracking configuration for reasoning about log injection vulnerabilities.
+   */
+  class Configuration extends TaintTracking::Configuration {
+    Configuration() { this = "LogInjection" }
+
+    override predicate isSource(DataFlow::Node source) { source instanceof Source }
+
+    override predicate isSink(DataFlow::Node sink) { sink instanceof Sink }
+
+    override predicate isSanitizer(DataFlow::Node sanitizer) { sanitizer instanceof Sanitizer }
+
+    override predicate isSanitizerGuard(DataFlow::BarrierGuard guard) {
+      guard instanceof SanitizerGuard
+    }
+  }
+}

repo-tests/codeql-go/ql/lib/semmle/go/security/LogInjectionCustomizations.qll

@@ -0,0 +1,42 @@
+/**
+ * Provides default sources, sinks, and sanitizers for reasoning about
+ * log injection vulnerabilities, as well as extension points for adding your own.
+ */
+
+import go
+
+/**
+ * Provides extension points for customizing the data-flow tracking configuration for reasoning
+ * about log injection.
+ */
+module LogInjection {
+  /**
+   * A data flow source for log injection vulnerabilities.
+   */
+  abstract class Source extends DataFlow::Node { }
+
+  /**
+   * A data flow sink for log injection vulnerabilities.
+   */
+  abstract class Sink extends DataFlow::Node { }
+
+  /**
+   * A sanitizer for log injection vulnerabilities.
+   */
+  abstract class Sanitizer extends DataFlow::Node { }
+
+  /**
+   * A sanitizer guard for log injection vulnerabilities.
+   */
+  abstract class SanitizerGuard extends DataFlow::BarrierGuard { }
+
+  /** A source of untrusted data, considered as a taint source for log injection. */
+  class UntrustedFlowAsSource extends Source {
+    UntrustedFlowAsSource() { this instanceof UntrustedFlowSource }
+  }
+
+  /** An argument to a logging mechanism. */
+  class LoggerSink extends Sink {
+    LoggerSink() { this = any(LoggerCall log).getAMessageComponent() }
+  }
+}

repo-tests/codeql-go/ql/lib/semmle/go/security/TaintedPath.qll

@@ -27,7 +27,7 @@ module TaintedPath {
     }
 
     override predicate isSanitizerGuard(DataFlow::BarrierGuard guard) {
-      guard instanceof SanitizerGuard
+      guard instanceof SanitizerGuardAsBarrierGuard
     }
   }
 }

repo-tests/codeql-go/ql/lib/semmle/go/security/TaintedPathCustomizations.qll

@@ -28,8 +28,30 @@ module TaintedPath {
 
   /**
    * A sanitizer guard for path-traversal vulnerabilities.
+   *
+   * Note this class should be extended to define more taint-path sanitizer guards, but isn't itself a
+   * `DataFlow::BarrierGuard` so that other queries can use this to define `BarrierGuard`s without
+   * introducing recursion. The class `SanitizerGuardAsBarrierGuard` plugs all instances of this class
+   * into the `DataFlow::BarrierGuard` type hierarchy.
    */
-  abstract class SanitizerGuard extends DataFlow::BarrierGuard { }
+  abstract class SanitizerGuard extends DataFlow::Node {
+    abstract predicate checks(Expr e, boolean branch);
+  }
+
+  /**
+   * A sanitizer guard for path-traversal vulnerabilities, as a `DataFlow::BarrierGuard`.
+   *
+   * Use this class if you want all `TaintedPath::SanitizerGuard`s as a `DataFlow::BarrierGuard`,
+   * e.g. to use directly in a `DataFlow::Configuration::isSanitizerGuard` method. If you want to
+   * provide a new instance of a tainted path sanitizer, extend `TaintedPath::SanitizerGuard` instead.
+   */
+  class SanitizerGuardAsBarrierGuard extends DataFlow::BarrierGuard {
+    SanitizerGuard guardImpl;
+
+    SanitizerGuardAsBarrierGuard() { this = guardImpl }
+
+    override predicate checks(Expr e, boolean branch) { guardImpl.checks(e, branch) }
+  }
 
   /** A source of untrusted data, considered as a taint source for path traversal. */
   class UntrustedFlowAsSource extends Source {
@@ -134,5 +156,9 @@ module TaintedPath {
    *
    * This is overapproximate: we do not attempt to reason about the correctness of the regexp.
    */
-  class RegexpCheckAsSanitizerGuard extends RegexpCheck, SanitizerGuard { }
+  class RegexpCheckAsSanitizerGuard extends SanitizerGuard {
+    RegexpCheckAsSanitizerGuard() { regexpFunctionChecksExpr(this, _, _) }
+
+    override predicate checks(Expr e, boolean branch) { regexpFunctionChecksExpr(this, e, branch) }
+  }
 }

repo-tests/codeql-go/ql/lib/semmle/go/security/ZipSlipCustomizations.qll

@@ -86,6 +86,27 @@ module ZipSlip {
     TaintedPathSanitizerAsSanitizer() { this instanceof TaintedPath::Sanitizer }
   }
 
+  pragma[noinline]
+  private predicate taintedPathGuardChecks(
+    TaintedPath::SanitizerGuard guard, DataFlow::Node checked, boolean branch
+  ) {
+    guard.checks(checked.asExpr(), branch)
+  }
+
+  pragma[noinline]
+  private predicate taintFlowsToCheckedNode(DataFlow::Node source, DataFlow::Node checked) {
+    taintedPathGuardChecks(_, checked, _) and
+    (
+      // Manual magic that is equivalent to `localTaint(source, checked)`
+      source = checked
+      or
+      exists(DataFlow::Node succ |
+        taintFlowsToCheckedNode(succ, checked) and
+        TaintTracking::localTaintStep(source, succ)
+      )
+    )
+  }
+
   /**
    * A sanitizer guard for zip-slip vulnerabilities which backtracks to sanitize expressions
    * that locally flow into a guarded expression. For example, an ordinary sanitizer guard
@@ -106,8 +127,8 @@ module ZipSlip {
 
     override predicate checks(Expr e, boolean branch) {
       exists(DataFlow::Node source, DataFlow::Node checked |
-        taintedPathGuard.checks(checked.asExpr(), branch) and
-        TaintTracking::localTaint(source, checked)
+        taintedPathGuardChecks(taintedPathGuard, checked, branch) and
+        taintFlowsToCheckedNode(source, checked)
       |
         e = source.asExpr()
       )

repo-tests/codeql-go/ql/src/Security/CWE-117/LogInjection.ql

@@ -0,0 +1,21 @@
+/**
+ * @name Log entries created from user input
+ * @description Building log entries from user-controlled sources is vulnerable to
+ *              insertion of forged log entries by a malicious user.
+ * @kind path-problem
+ * @problem.severity error
+ * @security-severity 7.8
+ * @precision high
+ * @id go/log-injection
+ * @tags security
+ *       external/cwe/cwe-117
+ */
+
+import go
+import semmle.go.security.LogInjection
+import DataFlow::PathGraph
+
+from LogInjection::Configuration c, DataFlow::PathNode source, DataFlow::PathNode sink
+where c.hasFlowPath(source, sink)
+select sink, source, sink, "This log write receives unsanitized user input from $@.",
+  source.getNode(), "here"

repo-tests/codeql-go/ql/src/Security/CWE-322/InsecureHostKeyCallback.ql

@@ -22,7 +22,7 @@ class InsecureIgnoreHostKey extends Function {
 class HostKeyCallbackFunc extends DataFlow::Node {
   HostKeyCallbackFunc() {
     exists(NamedType nt | nt.hasQualifiedName(CryptoSsh::packagePath(), "HostKeyCallback") |
-      getType().getUnderlyingType() = nt.getUnderlyingType()
+      this.getType().getUnderlyingType() = nt.getUnderlyingType()
     ) and
     // Restrict possible sources to either function definitions or
     // the result of some external function call (e.g. InsecureIgnoreHostKey())
@@ -71,7 +71,7 @@ class HostKeyCallbackAssignmentConfig extends DataFlow::Configuration {
     )
   }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, _) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, _) }
 }
 
 /**

repo-tests/codeql-go/ql/src/Security/CWE-352/ConstantOauth2State.ql

@@ -46,7 +46,7 @@ class ConstantStateFlowConf extends DataFlow::Configuration {
     )
   }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, _) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, _) }
 }
 
 /**
@@ -113,7 +113,7 @@ class PrivateUrlFlowsToAuthCodeUrlCall extends DataFlow::Configuration {
     exists(AuthCodeURL m | call = m.getACall() | sink = call.getReceiver())
   }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, _) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, _) }
 }
 
 /**
@@ -142,7 +142,7 @@ class FlowToPrint extends DataFlow::Configuration {
     source = any(AuthCodeURL m).getACall().getResult()
   }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, _) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, _) }
 }
 
 /** Holds if the provided `CallNode`'s result flows to an argument of a printer call. */

repo-tests/codeql-go/ql/src/experimental/CWE-327/CryptoLibraries.qll

@@ -196,7 +196,7 @@ abstract class CryptographicOperation extends DataFlow::Node {
  * Models cryptographic operations of the `crypto/md5` package.
  */
 class Md5 extends CryptographicOperation, DataFlow::CallNode {
-  Md5() { getTarget().hasQualifiedName("crypto/md5", ["New", "Sum"]) }
+  Md5() { this.getTarget().hasQualifiedName("crypto/md5", ["New", "Sum"]) }
 
   override Expr getInput() { result = this.getArgument(0).asExpr() }
 
@@ -209,7 +209,7 @@ class Md5 extends CryptographicOperation, DataFlow::CallNode {
  * Models cryptographic operations of the `crypto/sha1` package.
  */
 class Sha1 extends CryptographicOperation, DataFlow::CallNode {
-  Sha1() { getTarget().hasQualifiedName("crypto/sha1", ["New", "Sum"]) }
+  Sha1() { this.getTarget().hasQualifiedName("crypto/sha1", ["New", "Sum"]) }
 
   override Expr getInput() { result = this.getArgument(0).asExpr() }
 
@@ -222,7 +222,7 @@ class Sha1 extends CryptographicOperation, DataFlow::CallNode {
  * Models cryptographic operations of the `crypto/des` package.
  */
 class Des extends CryptographicOperation, DataFlow::CallNode {
-  Des() { getTarget().hasQualifiedName("crypto/des", ["NewCipher", "NewTripleDESCipher"]) }
+  Des() { this.getTarget().hasQualifiedName("crypto/des", ["NewCipher", "NewTripleDESCipher"]) }
 
   override Expr getInput() { result = this.getArgument(0).asExpr() }
 
@@ -235,7 +235,7 @@ class Des extends CryptographicOperation, DataFlow::CallNode {
  * Models cryptographic operations of the `crypto/rc4` package.
  */
 class Rc4 extends CryptographicOperation, DataFlow::CallNode {
-  Rc4() { getTarget().hasQualifiedName("crypto/rc4", ["NewCipher"]) }
+  Rc4() { this.getTarget().hasQualifiedName("crypto/rc4", ["NewCipher"]) }
 
   override Expr getInput() { result = this.getArgument(0).asExpr() }
 

repo-tests/codeql-go/ql/src/experimental/CWE-942/CorsMisconfiguration.ql

@@ -69,7 +69,7 @@ class FlowsUntrustedToAllowOriginHeader extends TaintTracking::Configuration {
     )
   }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, _) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, _) }
 }
 
 /**
@@ -128,7 +128,7 @@ class FlowsFromUntrusted extends TaintTracking::Configuration {
 
   override predicate isSource(DataFlow::Node source) { source instanceof UntrustedFlowSource }
 
-  override predicate isSink(DataFlow::Node sink) { isSink(sink, _) }
+  override predicate isSink(DataFlow::Node sink) { this.isSink(sink, _) }
 
   predicate isSink(DataFlow::Node sink, ControlFlow::ConditionGuardNode cgn) {
     exists(IfStmt ifs |

repo-tests/codeql.txt

@@ -1 +1 @@
-1f3f7e9ccc631177f671f3d465faec3477cbe1c5
+3c59aa319ee79d8038eec863df7ab18372c7b30e

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/controlflow/internal/ConstantExprs.qll

@@ -626,9 +626,9 @@ library class ExprEvaluator extends int {
       // All assignments must have the same int value
       result =
         unique(Expr value |
-          value = v.getAnAssignedValue() and not ignoreVariableAssignment(e, v, value)
+          value = v.getAnAssignedValue() and not this.ignoreVariableAssignment(e, v, value)
         |
-          getValueInternalNonSubExpr(value)
+          this.getValueInternalNonSubExpr(value)
         )
     )
   }

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl2.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl3.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl4.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplConsistency.qll

@@ -9,6 +9,19 @@ private import tainttracking1.TaintTrackingParameter::Private
 private import tainttracking1.TaintTrackingParameter::Public
 
 module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+  }
+
   private class RelevantNode extends Node {
     RelevantNode() {
       this instanceof ArgumentNode or
@@ -164,7 +177,7 @@ module Consistency {
 
   query predicate argHasPostUpdate(ArgumentNode n, string msg) {
     not hasPost(n) and
-    not isImmutableOrUnobservable(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
     msg = "ArgumentNode is missing PostUpdateNode."
   }
 
@@ -177,6 +190,7 @@ module Consistency {
     isPostUpdateNode(n) and
     not clearsContent(n, _) and
     simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
     msg = "PostUpdateNode should not be the target of local flow."
   }
 }

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImplLocal.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowPrivate.qll

@@ -2,6 +2,7 @@ private import cpp
 private import DataFlowUtil
 private import DataFlowDispatch
 private import FlowVar
+private import DataFlowImplConsistency
 
 /** Gets the callable in which this node occurs. */
 DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
@@ -259,27 +260,6 @@ class Unit extends TUnit {
   string toString() { result = "unit" }
 }
 
-/**
- * Holds if `n` does not require a `PostUpdateNode` as it either cannot be
- * modified or its modification cannot be observed, for example if it is a
- * freshly created object that is not saved in a variable.
- *
- * This predicate is only used for consistency checks.
- */
-predicate isImmutableOrUnobservable(Node n) {
-  // Is the null pointer (or something that's not really a pointer)
-  exists(n.asExpr().getValue())
-  or
-  // Isn't a pointer or is a pointer to const
-  forall(DerivedType dt | dt = n.asExpr().getActualType() |
-    dt.getBaseType().isConst()
-    or
-    dt.getBaseType() instanceof RoutineType
-  )
-  // The above list of cases isn't exhaustive, but it narrows down the
-  // consistency alerts enough that most of them are interesting.
-}
-
 /** Holds if `n` should be hidden from path explanations. */
 predicate nodeIsHidden(Node n) { none() }
 
@@ -302,3 +282,19 @@ predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preserves
  * by default as a heuristic.
  */
 predicate allowParameterReturnInSelf(ParameterNode p) { none() }
+
+private class MyConsistencyConfiguration extends Consistency::ConsistencyConfiguration {
+  override predicate argHasPostUpdateExclude(ArgumentNode n) {
+    // Is the null pointer (or something that's not really a pointer)
+    exists(n.asExpr().getValue())
+    or
+    // Isn't a pointer or is a pointer to const
+    forall(DerivedType dt | dt = n.asExpr().getActualType() |
+      dt.getBaseType().isConst()
+      or
+      dt.getBaseType() instanceof RoutineType
+    )
+    // The above list of cases isn't exhaustive, but it narrows down the
+    // consistency alerts enough that most of them are interesting.
+  }
+}

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/DefaultTaintTracking.qll

@@ -484,8 +484,9 @@ module TaintedWithPath {
     /** Gets the element that `pathNode` wraps, if any. */
     Element getElementFromPathNode(PathNode pathNode) {
       exists(DataFlow::Node node | node = pathNode.(WrapPathNode).inner().getNode() |
-        result = node.asExpr() or
-        result = node.asParameter()
+        result = node.asInstruction().getAST()
+        or
+        result = node.asOperand().getDef().getAST()
       )
       or
       result = pathNode.(EndpointPathNode).inner()

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl2.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl3.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl4.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImplConsistency.qll

@@ -9,6 +9,19 @@ private import tainttracking1.TaintTrackingParameter::Private
 private import tainttracking1.TaintTrackingParameter::Public
 
 module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+  }
+
   private class RelevantNode extends Node {
     RelevantNode() {
       this instanceof ArgumentNode or
@@ -164,7 +177,7 @@ module Consistency {
 
   query predicate argHasPostUpdate(ArgumentNode n, string msg) {
     not hasPost(n) and
-    not isImmutableOrUnobservable(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
     msg = "ArgumentNode is missing PostUpdateNode."
   }
 
@@ -177,6 +190,7 @@ module Consistency {
     isPostUpdateNode(n) and
     not clearsContent(n, _) and
     simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
     msg = "PostUpdateNode should not be the target of local flow."
   }
 }

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -2,6 +2,7 @@ private import cpp
 private import DataFlowUtil
 private import semmle.code.cpp.ir.IR
 private import DataFlowDispatch
+private import DataFlowImplConsistency
 
 /** Gets the callable in which this node occurs. */
 DataFlowCallable nodeGetEnclosingCallable(Node n) { result = n.getEnclosingCallable() }
@@ -285,21 +286,18 @@ class Unit extends TUnit {
   string toString() { result = "unit" }
 }
 
-/**
- * Holds if `n` does not require a `PostUpdateNode` as it either cannot be
- * modified or its modification cannot be observed, for example if it is a
- * freshly created object that is not saved in a variable.
- *
- * This predicate is only used for consistency checks.
- */
-predicate isImmutableOrUnobservable(Node n) {
-  // The rules for whether an IR argument gets a post-update node are too
-  // complex to model here.
-  any()
-}
-
 /** Holds if `n` should be hidden from path explanations. */
-predicate nodeIsHidden(Node n) { n instanceof OperandNode and not n instanceof ArgumentNode }
+predicate nodeIsHidden(Node n) {
+  n instanceof OperandNode and not n instanceof ArgumentNode
+  or
+  StoreNodeFlow::flowThrough(n, _) and
+  not StoreNodeFlow::flowOutOf(n, _) and
+  not StoreNodeFlow::flowInto(_, n)
+  or
+  ReadNodeFlow::flowThrough(n, _) and
+  not ReadNodeFlow::flowOutOf(n, _) and
+  not ReadNodeFlow::flowInto(_, n)
+}
 
 class LambdaCallKind = Unit;
 
@@ -320,3 +318,11 @@ predicate additionalLambdaFlowStep(Node nodeFrom, Node nodeTo, boolean preserves
  * by default as a heuristic.
  */
 predicate allowParameterReturnInSelf(ParameterNode p) { none() }
+
+private class MyConsistencyConfiguration extends Consistency::ConsistencyConfiguration {
+  override predicate argHasPostUpdateExclude(ArgumentNode n) {
+    // The rules for whether an IR argument gets a post-update node are too
+    // complex to model here.
+    any()
+  }
+}

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -452,7 +452,7 @@ class SsaPhiNode extends Node, TSsaPhiNode {
 
   /** Holds if this phi node has input from the `rnk`'th write operation in block `block`. */
   final predicate hasInputAtRankInBlock(IRBlock block, int rnk) {
-    hasInputAtRankInBlock(block, rnk, _)
+    this.hasInputAtRankInBlock(block, rnk, _)
   }
 
   /**
@@ -806,7 +806,7 @@ predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   simpleOperandLocalFlowStep(nodeFrom.asInstruction(), nodeTo.asOperand())
   or
   // Flow into, through, and out of store nodes
-  StoreNodeFlow::flowInto(nodeFrom, nodeTo)
+  StoreNodeFlow::flowInto(nodeFrom.asInstruction(), nodeTo)
   or
   StoreNodeFlow::flowThrough(nodeFrom, nodeTo)
   or
@@ -831,23 +831,19 @@ private predicate adjacentDefUseFlow(Node nodeFrom, Node nodeTo) {
     //Def-use flow
     Ssa::ssaFlow(nodeFrom, nodeTo)
     or
-    exists(Instruction loadAddress | loadAddress = Ssa::getSourceAddressFromNode(nodeFrom) |
-      // Use-use flow through reads
-      exists(Node address |
-        Ssa::addressFlowTC(address.asInstruction(), loadAddress) and
-        Ssa::ssaFlow(address, nodeTo)
-      )
-      or
-      // Use-use flow through stores.
-      exists(Node store |
-        Ssa::explicitWrite(_, store.asInstruction(), loadAddress) and
-        Ssa::ssaFlow(store, nodeTo)
-      )
+    // Use-use flow through stores.
+    exists(Instruction loadAddress, Node store |
+      loadAddress = Ssa::getSourceAddressFromNode(nodeFrom) and
+      Ssa::explicitWrite(_, store.asInstruction(), loadAddress) and
+      Ssa::ssaFlow(store, nodeTo)
     )
   )
 }
 
-private module ReadNodeFlow {
+/**
+ * INTERNAL: Do not use.
+ */
+module ReadNodeFlow {
   /** Holds if the read node `nodeTo` should receive flow from `nodeFrom`. */
   predicate flowInto(Node nodeFrom, ReadNode nodeTo) {
     nodeTo.isInitial() and
@@ -867,7 +863,12 @@ private module ReadNodeFlow {
     )
   }
 
-  /** Holds if the read node `nodeTo` should receive flow from the read node `nodeFrom`. */
+  /**
+   * Holds if the read node `nodeTo` should receive flow from the read node `nodeFrom`.
+   *
+   * This happens when `readFrom` is _not_ the source of a `readStep`, and `nodeTo` is
+   * the `ReadNode` that represents an address that directly depends on `nodeFrom`.
+   */
   predicate flowThrough(ReadNode nodeFrom, ReadNode nodeTo) {
     not readStep(nodeFrom, _, _) and
     nodeFrom.getOuter() = nodeTo
@@ -906,17 +907,25 @@ private module ReadNodeFlow {
   }
 }
 
-private module StoreNodeFlow {
+/**
+ * INTERNAL: Do not use.
+ */
+module StoreNodeFlow {
   /** Holds if the store node `nodeTo` should receive flow from `nodeFrom`. */
-  predicate flowInto(Node nodeFrom, StoreNode nodeTo) {
-    nodeTo.flowInto(Ssa::getDestinationAddress(nodeFrom.asInstruction()))
+  predicate flowInto(Instruction instrFrom, StoreNode nodeTo) {
+    nodeTo.flowInto(Ssa::getDestinationAddress(instrFrom))
   }
 
-  /** Holds if the store node `nodeTo` should receive flow from `nodeFom`. */
-  predicate flowThrough(StoreNode nFrom, StoreNode nodeTo) {
+  /**
+   * Holds if the store node `nodeTo` should receive flow from `nodeFom`.
+   *
+   * This happens when `nodeFrom` is _not_ the source of a `storeStep`, and `nodeFrom` is
+   * the `Storenode` that represents an address that directly depends on `nodeTo`.
+   */
+  predicate flowThrough(StoreNode nodeFrom, StoreNode nodeTo) {
     // Flow through a post update node that doesn't need a store step.
-    not storeStep(nFrom, _, _) and
-    nodeTo.getOuter() = nFrom
+    not storeStep(nodeFrom, _, _) and
+    nodeTo.getOuter() = nodeFrom
   }
 
   /**

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImplCommon.qll

@@ -634,3 +634,29 @@ class UncertainWriteDefinition extends WriteDefinition {
     )
   }
 }
+
+/** Provides a set of consistency queries. */
+module Consistency {
+  abstract class RelevantDefinition extends Definition {
+    abstract predicate hasLocationInfo(
+      string filepath, int startline, int startcolumn, int endline, int endcolumn
+    );
+  }
+
+  query predicate nonUniqueDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    ssaDefReachesRead(v, def, bb, i) and
+    not exists(unique(Definition def0 | ssaDefReachesRead(v, def0, bb, i)))
+  }
+
+  query predicate readWithoutDef(SourceVariable v, BasicBlock bb, int i) {
+    variableRead(bb, i, v, _) and
+    not ssaDefReachesRead(v, _, bb, i)
+  }
+
+  query predicate deadDef(RelevantDefinition def, SourceVariable v) {
+    v = def.getSourceVariable() and
+    not ssaDefReachesRead(_, def, _, _) and
+    not phiHasInputFromBlock(_, def, _) and
+    not uncertainWriteDefinitionInput(_, def)
+  }
+}

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternals.qll

@@ -244,17 +244,6 @@ Instruction getDestinationAddress(Instruction instr) {
     ]
 }
 
-class ReferenceToInstruction extends CopyValueInstruction {
-  ReferenceToInstruction() {
-    this.getResultType() instanceof Cpp::ReferenceType and
-    not this.getUnary().getResultType() instanceof Cpp::ReferenceType
-  }
-
-  Instruction getSourceAddress() { result = getSourceAddressOperand().getDef() }
-
-  Operand getSourceAddressOperand() { result = this.getUnaryOperand() }
-}
-
 /** Gets the source address of `instr` if it is an instruction that behaves like a `LoadInstruction`. */
 Instruction getSourceAddress(Instruction instr) { result = getSourceAddressOperand(instr).getDef() }
 
@@ -266,11 +255,7 @@ Operand getSourceAddressOperand(Instruction instr) {
   result =
     [
       instr.(LoadInstruction).getSourceAddressOperand(),
-      instr.(ReadSideEffectInstruction).getArgumentOperand(),
-      // `ReferenceToInstruction` is really more of an address-of operation,
-      // but by including it in this list we break out of `flowOutOfAddressStep` at an
-      // instruction that, at the source level, looks like a use of a variable.
-      instr.(ReferenceToInstruction).getSourceAddressOperand()
+      instr.(ReadSideEffectInstruction).getArgumentOperand()
     ]
 }
 
@@ -295,10 +280,6 @@ Operand getSourceValueOperand(Instruction instr) {
   result = instr.(LoadInstruction).getSourceValueOperand()
   or
   result = instr.(ReadSideEffectInstruction).getSideEffectOperand()
-  or
-  // See the comment on the `ReferenceToInstruction` disjunct in `getSourceAddressOperand` for why
-  // this case is included.
-  result = instr.(ReferenceToInstruction).getSourceValueOperand()
 }
 
 /**
@@ -513,6 +494,64 @@ private module Cached {
       explicitWrite(false, storeNode.getStoreInstruction(), def)
     )
     or
+    // The destination of a store operation has undergone lvalue-to-rvalue conversion and is now a
+    // right-hand-side of a store operation.
+    // Find the next use of the variable in that store operation, and recursively find the load of that
+    // pointer. For example, consider this case:
+    //
+    // ```cpp
+    // int x = source();
+    // int* p = &x;
+    // sink(*p);
+    // ```
+    //
+    // if we want to find the load of the address of `x`, we see that the pointer is stored into `p`,
+    // and we then need to recursively look for the load of `p`.
+    exists(
+      Def def, StoreInstruction store, IRBlock block1, int rnk1, Use use, IRBlock block2, int rnk2
+    |
+      store = def.getInstruction() and
+      store.getSourceValueOperand() = operand and
+      def.hasRankInBlock(block1, rnk1) and
+      use.hasRankInBlock(block2, rnk2) and
+      adjacentDefRead(_, block1, rnk1, block2, rnk2)
+    |
+      // The shared SSA library has determined that `use` is the next use of the operand
+      // so we find the next load of that use (but only if there is no `PostUpdateNode`) we
+      // need to flow into first.
+      not StoreNodeFlow::flowInto(store, _) and
+      flowOutOfAddressStep(use.getOperand(), nodeTo)
+      or
+      // It may also be the case that `store` gives rise to another store step. So let's make sure that
+      // we also take those into account.
+      StoreNodeFlow::flowInto(store, nodeTo)
+    )
+    or
+    // As we find the next load of an address, we might come across another use of the same variable.
+    // In that case, we recursively find the next use of _that_ operand, and continue searching for
+    // the next load of that operand. For example, consider this case:
+    //
+    // ```cpp
+    // int x = source();
+    // use(&x);
+    // int* p = &x;
+    // sink(*p);
+    // ```
+    //
+    // The next use of `x` after its definition is `use(&x)`, but there is a later load of the address
+    // of `x` that we want to flow to. So we use the shared SSA library to find the next load.
+    not operand = getSourceAddressOperand(_) and
+    exists(Use use1, Use use2, IRBlock block1, int rnk1, IRBlock block2, int rnk2 |
+      use1.getOperand() = operand and
+      use1.hasRankInBlock(block1, rnk1) and
+      // Don't flow to the next use if this use is part of a store operation that totally
+      // overrides a variable.
+      not explicitWrite(true, _, use1.getOperand().getDef()) and
+      adjacentDefRead(_, block1, rnk1, block2, rnk2) and
+      use2.hasRankInBlock(block2, rnk2) and
+      flowOutOfAddressStep(use2.getOperand(), nodeTo)
+    )
+    or
     operand = getSourceAddressOperand(nodeTo.asInstruction())
     or
     exists(ReturnIndirectionInstruction ret |

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/Operand.qll

@@ -20,6 +20,14 @@ private import internal.OperandInternal
 private class TStageOperand =
   TRegisterOperand or TNonSSAMemoryOperand or TPhiOperand or TChiOperand;
 
+/**
+ * A known location. Testing `loc instanceof KnownLocation` will account for non existing locations, as
+ * opposed to testing `not loc isntanceof UnknownLocation`
+ */
+private class KnownLocation extends Language::Location {
+  KnownLocation() { not this instanceof Language::UnknownLocation }
+}
+
 /**
  * An operand of an `Instruction`. The operand represents a use of the result of one instruction
  * (the defining instruction) in another instruction (the use instruction)
@@ -45,8 +53,10 @@ class Operand extends TStageOperand {
 
   /**
    * Gets the location of the source code for this operand.
+   * By default this is where the operand is used, but some subclasses may override this
+   * using `getAnyDef()` if it makes more sense.
    */
-  final Language::Location getLocation() { result = this.getUse().getLocation() }
+  Language::Location getLocation() { result = this.getUse().getLocation() }
 
   /**
    * Gets the function that contains this operand.
@@ -269,6 +279,10 @@ class RegisterOperand extends NonPhiOperand, TRegisterOperand {
 
   final override string toString() { result = tag.toString() }
 
+  // most `RegisterOperands` have a more meaningful location at the definition
+  // the only exception are specific cases of `ThisArgumentOperand`
+  override Language::Location getLocation() { result = this.getAnyDef().getLocation() }
+
   final override Instruction getAnyDef() { result = defInstr }
 
   final override Overlap getDefinitionOverlap() {
@@ -293,7 +307,7 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, TNonPhiMemoryOpe
   final override string toString() { result = tag.toString() }
 
   final override Instruction getAnyDef() {
-    result = unique(Instruction defInstr | hasDefinition(defInstr, _))
+    result = unique(Instruction defInstr | this.hasDefinition(defInstr, _))
   }
 
   final override Overlap getDefinitionOverlap() { this.hasDefinition(_, result) }
@@ -401,11 +415,19 @@ class ArgumentOperand extends RegisterOperand {
 }
 
 /**
- * An operand representing the implicit 'this' argument to a member function
+ * An operand representing the implicit `this` argument to a member function
  * call.
  */
 class ThisArgumentOperand extends ArgumentOperand {
   override ThisArgumentOperandTag tag;
+
+  // in most cases the def location makes more sense, but in some corner cases it
+  // has an unknown location: in those cases we fall back to the use location
+  override Language::Location getLocation() {
+    if this.getAnyDef().getLocation() instanceof KnownLocation
+    then result = this.getAnyDef().getLocation()
+    else result = this.getUse().getLocation()
+  }
 }
 
 /**

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/Operand.qll

@@ -20,6 +20,14 @@ private import internal.OperandInternal
 private class TStageOperand =
   TRegisterOperand or TNonSSAMemoryOperand or TPhiOperand or TChiOperand;
 
+/**
+ * A known location. Testing `loc instanceof KnownLocation` will account for non existing locations, as
+ * opposed to testing `not loc isntanceof UnknownLocation`
+ */
+private class KnownLocation extends Language::Location {
+  KnownLocation() { not this instanceof Language::UnknownLocation }
+}
+
 /**
  * An operand of an `Instruction`. The operand represents a use of the result of one instruction
  * (the defining instruction) in another instruction (the use instruction)
@@ -45,8 +53,10 @@ class Operand extends TStageOperand {
 
   /**
    * Gets the location of the source code for this operand.
+   * By default this is where the operand is used, but some subclasses may override this
+   * using `getAnyDef()` if it makes more sense.
    */
-  final Language::Location getLocation() { result = this.getUse().getLocation() }
+  Language::Location getLocation() { result = this.getUse().getLocation() }
 
   /**
    * Gets the function that contains this operand.
@@ -269,6 +279,10 @@ class RegisterOperand extends NonPhiOperand, TRegisterOperand {
 
   final override string toString() { result = tag.toString() }
 
+  // most `RegisterOperands` have a more meaningful location at the definition
+  // the only exception are specific cases of `ThisArgumentOperand`
+  override Language::Location getLocation() { result = this.getAnyDef().getLocation() }
+
   final override Instruction getAnyDef() { result = defInstr }
 
   final override Overlap getDefinitionOverlap() {
@@ -293,7 +307,7 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, TNonPhiMemoryOpe
   final override string toString() { result = tag.toString() }
 
   final override Instruction getAnyDef() {
-    result = unique(Instruction defInstr | hasDefinition(defInstr, _))
+    result = unique(Instruction defInstr | this.hasDefinition(defInstr, _))
   }
 
   final override Overlap getDefinitionOverlap() { this.hasDefinition(_, result) }
@@ -401,11 +415,19 @@ class ArgumentOperand extends RegisterOperand {
 }
 
 /**
- * An operand representing the implicit 'this' argument to a member function
+ * An operand representing the implicit `this` argument to a member function
  * call.
  */
 class ThisArgumentOperand extends ArgumentOperand {
   override ThisArgumentOperandTag tag;
+
+  // in most cases the def location makes more sense, but in some corner cases it
+  // has an unknown location: in those cases we fall back to the use location
+  override Language::Location getLocation() {
+    if this.getAnyDef().getLocation() instanceof KnownLocation
+    then result = this.getAnyDef().getLocation()
+    else result = this.getUse().getLocation()
+  }
 }
 
 /**

repo-tests/codeql/cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/Operand.qll

@@ -20,6 +20,14 @@ private import internal.OperandInternal
 private class TStageOperand =
   TRegisterOperand or TNonSSAMemoryOperand or TPhiOperand or TChiOperand;
 
+/**
+ * A known location. Testing `loc instanceof KnownLocation` will account for non existing locations, as
+ * opposed to testing `not loc isntanceof UnknownLocation`
+ */
+private class KnownLocation extends Language::Location {
+  KnownLocation() { not this instanceof Language::UnknownLocation }
+}
+
 /**
  * An operand of an `Instruction`. The operand represents a use of the result of one instruction
  * (the defining instruction) in another instruction (the use instruction)
@@ -45,8 +53,10 @@ class Operand extends TStageOperand {
 
   /**
    * Gets the location of the source code for this operand.
+   * By default this is where the operand is used, but some subclasses may override this
+   * using `getAnyDef()` if it makes more sense.
    */
-  final Language::Location getLocation() { result = this.getUse().getLocation() }
+  Language::Location getLocation() { result = this.getUse().getLocation() }
 
   /**
    * Gets the function that contains this operand.
@@ -269,6 +279,10 @@ class RegisterOperand extends NonPhiOperand, TRegisterOperand {
 
   final override string toString() { result = tag.toString() }
 
+  // most `RegisterOperands` have a more meaningful location at the definition
+  // the only exception are specific cases of `ThisArgumentOperand`
+  override Language::Location getLocation() { result = this.getAnyDef().getLocation() }
+
   final override Instruction getAnyDef() { result = defInstr }
 
   final override Overlap getDefinitionOverlap() {
@@ -293,7 +307,7 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, TNonPhiMemoryOpe
   final override string toString() { result = tag.toString() }
 
   final override Instruction getAnyDef() {
-    result = unique(Instruction defInstr | hasDefinition(defInstr, _))
+    result = unique(Instruction defInstr | this.hasDefinition(defInstr, _))
   }
 
   final override Overlap getDefinitionOverlap() { this.hasDefinition(_, result) }
@@ -401,11 +415,19 @@ class ArgumentOperand extends RegisterOperand {
 }
 
 /**
- * An operand representing the implicit 'this' argument to a member function
+ * An operand representing the implicit `this` argument to a member function
  * call.
  */
 class ThisArgumentOperand extends ArgumentOperand {
   override ThisArgumentOperandTag tag;
+
+  // in most cases the def location makes more sense, but in some corner cases it
+  // has an unknown location: in those cases we fall back to the use location
+  override Language::Location getLocation() {
+    if this.getAnyDef().getLocation() instanceof KnownLocation
+    then result = this.getAnyDef().getLocation()
+    else result = this.getUse().getLocation()
+  }
 }
 
 /**

repo-tests/codeql/cpp/ql/src/AlertSuppression.ql

@@ -18,12 +18,12 @@ class SuppressionComment extends Comment {
     (
       this instanceof CppStyleComment and
       // strip the beginning slashes
-      text = getContents().suffix(2)
+      text = this.getContents().suffix(2)
       or
       this instanceof CStyleComment and
       // strip both the beginning /* and the end */ the comment
       exists(string text0 |
-        text0 = getContents().suffix(2) and
+        text0 = this.getContents().suffix(2) and
         text = text0.prefix(text0.length() - 2)
       ) and
       // The /* */ comment must be a single-line comment

repo-tests/codeql/cpp/ql/src/Architecture/Refactoring Opportunities/ClassesWithManyFields.ql

@@ -153,12 +153,12 @@ class ExtClass extends Class {
   }
 
   predicate hasLocationInfo(string path, int startline, int startcol, int endline, int endcol) {
-    if hasOneVariableGroup()
+    if this.hasOneVariableGroup()
     then
       exists(VariableDeclarationGroup vdg | vdg.getClass() = this |
         vdg.hasLocationInfo(path, startline, startcol, endline, endcol)
       )
-    else getLocation().hasLocationInfo(path, startline, startcol, endline, endcol)
+    else this.getLocation().hasLocationInfo(path, startline, startcol, endline, endcol)
   }
 }
 

repo-tests/codeql/cpp/ql/src/Best Practices/Unused Entities/UnusedStaticFunctions.ql

@@ -50,6 +50,16 @@ predicate reachableThing(Thing t) {
   exists(Thing mid | reachableThing(mid) and mid.callsOrAccesses() = t)
 }
 
+pragma[nomagic]
+predicate callsOrAccessesPlus(Thing thing1, FunctionToRemove thing2) {
+  thing1.callsOrAccesses() = thing2
+  or
+  exists(Thing mid |
+    thing1.callsOrAccesses() = mid and
+    callsOrAccessesPlus(mid, thing2)
+  )
+}
+
 class Thing extends Locatable {
   Thing() {
     this instanceof Function or
@@ -81,7 +91,7 @@ class FunctionToRemove extends Function {
   }
 
   Thing getOther() {
-    result.callsOrAccesses+() = this and
+    callsOrAccessesPlus(result, this) and
     this != result and
     // We will already be reporting the enclosing function of a
     // local variable, so don't also report the variable

repo-tests/codeql/cpp/ql/src/Critical/OverflowStatic.ql

@@ -103,9 +103,9 @@ class CallWithBufferSize extends FunctionCall {
     // `upperBound(e)` defaults to `exprMaxVal(e)` when `e` isn't analyzable. So to get a meaningful
     // result in this case we pick the minimum value obtainable from dataflow and range analysis.
     result =
-      upperBound(statedSizeExpr())
+      upperBound(this.statedSizeExpr())
           .minimum(min(Expr statedSizeSrc |
-              DataFlow::localExprFlow(statedSizeSrc, statedSizeExpr())
+              DataFlow::localExprFlow(statedSizeSrc, this.statedSizeExpr())
             |
               statedSizeSrc.getValue().toInt()
             ))

repo-tests/codeql/cpp/ql/src/JPL_C/LOC-2/Rule 09/Semaphores.qll

@@ -22,7 +22,7 @@ abstract class LockOperation extends FunctionCall {
   ControlFlowNode getAReachedNode() {
     result = this
     or
-    exists(ControlFlowNode mid | mid = getAReachedNode() |
+    exists(ControlFlowNode mid | mid = this.getAReachedNode() |
       not mid != this.getMatchingUnlock() and
       result = mid.getASuccessor()
     )

repo-tests/codeql/cpp/ql/src/Likely Bugs/Leap Year/LeapYear.qll

@@ -156,8 +156,8 @@ abstract class LeapYearFieldAccess extends YearFieldAccess {
     //
     // https://aa.usno.navy.mil/faq/docs/calendars.php
     this.isUsedInMod4Operation() and
-    additionalModulusCheckForLeapYear(400) and
-    additionalModulusCheckForLeapYear(100)
+    this.additionalModulusCheckForLeapYear(400) and
+    this.additionalModulusCheckForLeapYear(100)
   }
 }
 
@@ -176,17 +176,17 @@ class StructTmLeapYearFieldAccess extends LeapYearFieldAccess {
 
   override predicate isUsedInCorrectLeapYearCheck() {
     this.isUsedInMod4Operation() and
-    additionalModulusCheckForLeapYear(400) and
-    additionalModulusCheckForLeapYear(100) and
+    this.additionalModulusCheckForLeapYear(400) and
+    this.additionalModulusCheckForLeapYear(100) and
     // tm_year represents years since 1900
     (
-      additionalAdditionOrSubstractionCheckForLeapYear(1900)
+      this.additionalAdditionOrSubstractionCheckForLeapYear(1900)
       or
       // some systems may use 2000 for 2-digit year conversions
-      additionalAdditionOrSubstractionCheckForLeapYear(2000)
+      this.additionalAdditionOrSubstractionCheckForLeapYear(2000)
       or
       // converting from/to Unix epoch
-      additionalAdditionOrSubstractionCheckForLeapYear(1970)
+      this.additionalAdditionOrSubstractionCheckForLeapYear(1970)
     )
   }
 }

repo-tests/codeql/cpp/ql/src/Likely Bugs/Memory Management/AllocaInLoop.ql

@@ -57,7 +57,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `e == 0`
     exists(EQExpr eq |
-      conditionRequires(eq, truth.booleanNot()) and
+      this.conditionRequires(eq, truth.booleanNot()) and
       eq.getAnOperand().getValue().toInt() = 0 and
       e = eq.getAnOperand() and
       not exists(e.getValue())
@@ -65,7 +65,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `e != 0`
     exists(NEExpr eq |
-      conditionRequires(eq, truth) and
+      this.conditionRequires(eq, truth) and
       eq.getAnOperand().getValue().toInt() = 0 and
       e = eq.getAnOperand() and
       not exists(e.getValue())
@@ -73,7 +73,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `(bool)e == true`
     exists(EQExpr eq |
-      conditionRequires(eq, truth) and
+      this.conditionRequires(eq, truth) and
       eq.getAnOperand().getValue().toInt() = 1 and
       e = eq.getAnOperand() and
       e.getUnspecifiedType() instanceof BoolType and
@@ -82,7 +82,7 @@ class LoopWithAlloca extends Stmt {
     or
     // `(bool)e != true`
     exists(NEExpr eq |
-      conditionRequires(eq, truth.booleanNot()) and
+      this.conditionRequires(eq, truth.booleanNot()) and
       eq.getAnOperand().getValue().toInt() = 1 and
       e = eq.getAnOperand() and
       e.getUnspecifiedType() instanceof BoolType and
@@ -90,7 +90,7 @@ class LoopWithAlloca extends Stmt {
     )
     or
     exists(NotExpr notExpr |
-      conditionRequires(notExpr, truth.booleanNot()) and
+      this.conditionRequires(notExpr, truth.booleanNot()) and
       e = notExpr.getOperand()
     )
     or
@@ -98,7 +98,7 @@ class LoopWithAlloca extends Stmt {
     // requires both of its operand to be true as well.
     exists(LogicalAndExpr andExpr |
       truth = true and
-      conditionRequires(andExpr, truth) and
+      this.conditionRequires(andExpr, truth) and
       e = andExpr.getAnOperand()
     )
     or
@@ -106,7 +106,7 @@ class LoopWithAlloca extends Stmt {
     // it requires both of its operand to be false as well.
     exists(LogicalOrExpr orExpr |
       truth = false and
-      conditionRequires(orExpr, truth) and
+      this.conditionRequires(orExpr, truth) and
       e = orExpr.getAnOperand()
     )
   }
@@ -141,9 +141,9 @@ class LoopWithAlloca extends Stmt {
    * `conditionRequiresInequality`.
    */
   private Variable getAControllingVariable() {
-    conditionRequires(result.getAnAccess(), _)
+    this.conditionRequires(result.getAnAccess(), _)
     or
-    conditionRequiresInequality(result.getAnAccess(), _, _)
+    this.conditionRequiresInequality(result.getAnAccess(), _, _)
   }
 
   /**

repo-tests/codeql/cpp/ql/src/Likely Bugs/Memory Management/NtohlArrayNoBound.qll

@@ -61,72 +61,72 @@ class PointerArithmeticAccess extends BufferAccess, Expr {
  * A pair of buffer accesses through a call to memcpy.
  */
 class MemCpy extends BufferAccess, FunctionCall {
-  MemCpy() { getTarget().hasName("memcpy") }
+  MemCpy() { this.getTarget().hasName("memcpy") }
 
   override Expr getPointer() {
-    result = getArgument(0) or
-    result = getArgument(1)
+    result = this.getArgument(0) or
+    result = this.getArgument(1)
   }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class StrncpySizeExpr extends BufferAccess, FunctionCall {
-  StrncpySizeExpr() { getTarget().hasName("strncpy") }
+  StrncpySizeExpr() { this.getTarget().hasName("strncpy") }
 
   override Expr getPointer() {
-    result = getArgument(0) or
-    result = getArgument(1)
+    result = this.getArgument(0) or
+    result = this.getArgument(1)
   }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class RecvSizeExpr extends BufferAccess, FunctionCall {
-  RecvSizeExpr() { getTarget().hasName("recv") }
+  RecvSizeExpr() { this.getTarget().hasName("recv") }
 
-  override Expr getPointer() { result = getArgument(1) }
+  override Expr getPointer() { result = this.getArgument(1) }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class SendSizeExpr extends BufferAccess, FunctionCall {
-  SendSizeExpr() { getTarget().hasName("send") }
+  SendSizeExpr() { this.getTarget().hasName("send") }
 
-  override Expr getPointer() { result = getArgument(1) }
+  override Expr getPointer() { result = this.getArgument(1) }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class SnprintfSizeExpr extends BufferAccess, FunctionCall {
-  SnprintfSizeExpr() { getTarget().hasName("snprintf") }
+  SnprintfSizeExpr() { this.getTarget().hasName("snprintf") }
 
-  override Expr getPointer() { result = getArgument(0) }
+  override Expr getPointer() { result = this.getArgument(0) }
 
-  override Expr getAccessedLength() { result = getArgument(1) }
+  override Expr getAccessedLength() { result = this.getArgument(1) }
 }
 
 class MemcmpSizeExpr extends BufferAccess, FunctionCall {
-  MemcmpSizeExpr() { getTarget().hasName("Memcmp") }
+  MemcmpSizeExpr() { this.getTarget().hasName("Memcmp") }
 
   override Expr getPointer() {
-    result = getArgument(0) or
-    result = getArgument(1)
+    result = this.getArgument(0) or
+    result = this.getArgument(1)
   }
 
-  override Expr getAccessedLength() { result = getArgument(2) }
+  override Expr getAccessedLength() { result = this.getArgument(2) }
 }
 
 class MallocSizeExpr extends BufferAccess, FunctionCall {
-  MallocSizeExpr() { getTarget().hasName("malloc") }
+  MallocSizeExpr() { this.getTarget().hasName("malloc") }
 
   override Expr getPointer() { none() }
 
-  override Expr getAccessedLength() { result = getArgument(0) }
+  override Expr getAccessedLength() { result = this.getArgument(0) }
 }
 
 class NetworkFunctionCall extends FunctionCall {
-  NetworkFunctionCall() { getTarget().hasName(["ntohd", "ntohf", "ntohl", "ntohll", "ntohs"]) }
+  NetworkFunctionCall() { this.getTarget().hasName(["ntohd", "ntohf", "ntohl", "ntohll", "ntohs"]) }
 }
 
 class NetworkToBufferSizeConfiguration extends DataFlow::Configuration {

repo-tests/codeql/cpp/ql/src/Likely Bugs/Protocols/TlsSettingsMisconfiguration.ql

@@ -3,8 +3,10 @@
  * @description Using the TLS or SSLv23 protocol from the boost::asio library, but not disabling deprecated protocols, or disabling minimum-recommended protocols.
  * @kind problem
  * @problem.severity error
+ * @security-severity 7.5
  * @id cpp/boost/tls-settings-misconfiguration
  * @tags security
+ *       external/cwe/cwe-326
  */
 
 import cpp

repo-tests/codeql/cpp/ql/src/Likely Bugs/Protocols/UseOfDeprecatedHardcodedProtocol.ql

@@ -3,8 +3,10 @@
  * @description Using a deprecated hard-coded protocol using the boost::asio library.
  * @kind problem
  * @problem.severity error
+ * @security-severity 7.5
  * @id cpp/boost/use-of-deprecated-hardcoded-security-protocol
  * @tags security
+ *       external/cwe/cwe-327
  */
 
 import cpp

repo-tests/codeql/cpp/ql/src/Power of 10/Rule 4/FunctionTooLong.ql

@@ -13,7 +13,7 @@ import cpp
 
 class MacroFunctionCall extends MacroInvocation {
   MacroFunctionCall() {
-    not exists(getParentInvocation()) and
+    not exists(this.getParentInvocation()) and
     this.getMacro().getHead().matches("%(%")
   }
 

repo-tests/codeql/cpp/ql/src/Power of 10/Rule 5/AssertionDensity.ql

@@ -13,7 +13,7 @@ import semmle.code.cpp.commons.Assertions
 
 class MacroFunctionCall extends MacroInvocation {
   MacroFunctionCall() {
-    not exists(getParentInvocation()) and
+    not exists(this.getParentInvocation()) and
     this.getMacro().getHead().matches("%(%")
   }
 

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-020/ExternalAPIsSpecific.qll

@@ -38,7 +38,7 @@ class ExternalAPIDataNode extends DataFlow::Node {
   int getIndex() { result = i }
 
   /** Gets the description of the function being called. */
-  string getFunctionDescription() { result = getExternalFunction().toString() }
+  string getFunctionDescription() { result = this.getExternalFunction().toString() }
 }
 
 /** A configuration for tracking flow from `RemoteFlowSource`s to `ExternalAPIDataNode`s. */

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-020/ir/ExternalAPIsSpecific.qll

@@ -38,7 +38,7 @@ class ExternalAPIDataNode extends DataFlow::Node {
   int getIndex() { result = i }
 
   /** Gets the description of the function being called. */
-  string getFunctionDescription() { result = getExternalFunction().toString() }
+  string getFunctionDescription() { result = this.getExternalFunction().toString() }
 }
 
 /** A configuration for tracking flow from `RemoteFlowSource`s to `ExternalAPIDataNode`s. */

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-121/UnterminatedVarargsCall.ql

@@ -42,7 +42,7 @@ class VarargsFunction extends Function {
   }
 
   private int trailingArgValueCount(string value) {
-    result = strictcount(FunctionCall fc | trailingArgValue(fc) = value)
+    result = strictcount(FunctionCall fc | this.trailingArgValue(fc) = value)
   }
 
   string nonTrailingVarArgValue(FunctionCall fc, int index) {
@@ -58,11 +58,11 @@ class VarargsFunction extends Function {
 
   string normalTerminator(int cnt) {
     result = ["0", "-1"] and
-    cnt = trailingArgValueCount(result) and
-    2 * cnt > totalCount() and
+    cnt = this.trailingArgValueCount(result) and
+    2 * cnt > this.totalCount() and
     not exists(FunctionCall fc, int index |
       // terminator value is used in a non-terminating position
-      nonTrailingVarArgValue(fc, index) = result
+      this.nonTrailingVarArgValue(fc, index) = result
     )
   }
 

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-170/ImproperNullTerminationTainted.ql

@@ -42,7 +42,7 @@ class TaintSource extends VariableAccess {
     definitionUsePair(_, this, va)
     or
     exists(VariableAccess mid, Expr def |
-      sourceReaches(mid) and
+      this.sourceReaches(mid) and
       exprDefinition(_, def, mid) and
       definitionUsePair(_, def, va)
     )
@@ -53,11 +53,11 @@ class TaintSource extends VariableAccess {
    * from `va`, possibly using intermediate reassignments.
    */
   private predicate reachesSink(VariableAccess va, VariableAccess sink) {
-    isSink(sink) and
+    this.isSink(sink) and
     va = sink
     or
     exists(VariableAccess mid, Expr def |
-      reachesSink(mid, sink) and
+      this.reachesSink(mid, sink) and
       exprDefinition(_, def, va) and
       definitionUsePair(_, def, mid)
     )
@@ -71,15 +71,15 @@ class TaintSource extends VariableAccess {
    * this source to `sink` found via `tainted(source, sink)`.)
    */
   predicate reaches(VariableAccess sink) {
-    isSink(sink) and
+    this.isSink(sink) and
     not exists(VariableAccess va |
       va != this and
       va != sink and
       mayAddNullTerminator(_, va)
     |
-      sourceReaches(va)
+      this.sourceReaches(va)
       or
-      reachesSink(va, sink)
+      this.reachesSink(va, sink)
     )
   }
 }

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-295/SSLResultConflation.ql

@@ -0,0 +1,50 @@
+/**
+ * @name Certificate result conflation
+ * @description Only accept SSL certificates that pass certificate verification.
+ * @kind problem
+ * @problem.severity error
+ * @security-severity 7.5
+ * @precision medium
+ * @id cpp/certificate-result-conflation
+ * @tags security
+ *       external/cwe/cwe-295
+ */
+
+import cpp
+import semmle.code.cpp.controlflow.Guards
+import semmle.code.cpp.dataflow.DataFlow
+
+/**
+ * A call to `SSL_get_verify_result`.
+ */
+class SSLGetVerifyResultCall extends FunctionCall {
+  SSLGetVerifyResultCall() { getTarget().getName() = "SSL_get_verify_result" }
+}
+
+/**
+ * Data flow from a call to `SSL_get_verify_result` to a guard condition
+ * that references the result.
+ */
+class VerifyResultConfig extends DataFlow::Configuration {
+  VerifyResultConfig() { this = "VerifyResultConfig" }
+
+  override predicate isSource(DataFlow::Node source) {
+    source.asExpr() instanceof SSLGetVerifyResultCall
+  }
+
+  override predicate isSink(DataFlow::Node sink) {
+    exists(GuardCondition guard | guard.getAChild*() = sink.asExpr())
+  }
+}
+
+from
+  VerifyResultConfig config, DataFlow::Node source, DataFlow::Node sink1, DataFlow::Node sink2,
+  GuardCondition guard, Expr c1, Expr c2, boolean testIsTrue
+where
+  config.hasFlow(source, sink1) and
+  config.hasFlow(source, sink2) and
+  guard.comparesEq(sink1.asExpr(), c1, 0, false, testIsTrue) and // (value != c1) => testIsTrue
+  guard.comparesEq(sink2.asExpr(), c2, 0, false, testIsTrue) and // (value != c2) => testIsTrue
+  c1.getValue().toInt() = 0 and
+  c2.getValue().toInt() != 0
+select guard, "This expression conflates OK and non-OK results from $@.", source, source.toString()

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-295/SSLResultNotChecked.ql

@@ -0,0 +1,120 @@
+/**
+ * @name Certificate not checked
+ * @description Always check the result of certificate verification after fetching an SSL certificate.
+ * @kind problem
+ * @problem.severity error
+ * @security-severity 7.5
+ * @precision medium
+ * @id cpp/certificate-not-checked
+ * @tags security
+ *       external/cwe/cwe-295
+ */
+
+import cpp
+import semmle.code.cpp.valuenumbering.GlobalValueNumbering
+import semmle.code.cpp.controlflow.IRGuards
+
+/**
+ * A call to `SSL_get_peer_certificate`.
+ */
+class SSLGetPeerCertificateCall extends FunctionCall {
+  SSLGetPeerCertificateCall() {
+    getTarget().getName() = "SSL_get_peer_certificate" // SSL_get_peer_certificate(ssl)
+  }
+
+  Expr getSSLArgument() { result = getArgument(0) }
+}
+
+/**
+ * A call to `SSL_get_verify_result`.
+ */
+class SSLGetVerifyResultCall extends FunctionCall {
+  SSLGetVerifyResultCall() {
+    getTarget().getName() = "SSL_get_verify_result" // SSL_get_peer_certificate(ssl)
+  }
+
+  Expr getSSLArgument() { result = getArgument(0) }
+}
+
+/**
+ * Holds if the SSL object passed into `SSL_get_peer_certificate` is checked with
+ * `SSL_get_verify_result` entering `node`.
+ */
+predicate resultIsChecked(SSLGetPeerCertificateCall getCertCall, ControlFlowNode node) {
+  exists(Expr ssl, SSLGetVerifyResultCall check |
+    ssl = globalValueNumber(getCertCall.getSSLArgument()).getAnExpr() and
+    ssl = check.getSSLArgument() and
+    node = check
+  )
+}
+
+/**
+ * Holds if the certificate returned by `SSL_get_peer_certificate` is found to be
+ * `0` on the edge `node1` to `node2`.
+ */
+predicate certIsZero(
+  SSLGetPeerCertificateCall getCertCall, ControlFlowNode node1, ControlFlowNode node2
+) {
+  exists(Expr cert | cert = globalValueNumber(getCertCall).getAnExpr() |
+    exists(GuardCondition guard, Expr zero |
+      zero.getValue().toInt() = 0 and
+      node1 = guard and
+      (
+        // if (cert == zero) {
+        guard.comparesEq(cert, zero, 0, true, true) and
+        node2 = guard.getATrueSuccessor()
+        or
+        // if (cert != zero) { }
+        guard.comparesEq(cert, zero, 0, false, true) and
+        node2 = guard.getAFalseSuccessor()
+      )
+    )
+    or
+    (
+      // if (cert) { }
+      node1 = cert
+      or
+      // if (!cert) {
+      node1.(NotExpr).getAChild() = cert
+    ) and
+    node2 = node1.getASuccessor() and
+    not cert.(GuardCondition).controls(node2, true) // cert may be false
+  )
+}
+
+/**
+ * Holds if the SSL object passed into `SSL_get_peer_certificate` has not been checked with
+ * `SSL_get_verify_result` at `node`. Note that this is only computed at the call to
+ * `SSL_get_peer_certificate` and at the start and end of `BasicBlock`s.
+ */
+predicate certNotChecked(SSLGetPeerCertificateCall getCertCall, ControlFlowNode node) {
+  // cert is not checked at the call to `SSL_get_peer_certificate`
+  node = getCertCall
+  or
+  exists(BasicBlock bb, int pos |
+    // flow to end of a `BasicBlock`
+    certNotChecked(getCertCall, bb.getNode(pos)) and
+    node = bb.getEnd() and
+    // check for barrier node
+    not exists(int pos2 |
+      pos2 > pos and
+      resultIsChecked(getCertCall, bb.getNode(pos2))
+    )
+  )
+  or
+  exists(BasicBlock pred, BasicBlock bb |
+    // flow from the end of one `BasicBlock` to the beginning of a successor
+    certNotChecked(getCertCall, pred.getEnd()) and
+    bb = pred.getASuccessor() and
+    node = bb.getStart() and
+    // check for barrier bb
+    not certIsZero(getCertCall, pred.getEnd(), bb.getStart())
+  )
+}
+
+from SSLGetPeerCertificateCall getCertCall, ControlFlowNode node
+where
+  certNotChecked(getCertCall, node) and
+  node instanceof Function // (function exit)
+select getCertCall,
+  "This " + getCertCall.toString() + " is not followed by a call to SSL_get_verify_result."

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-311/CleartextFileWrite.ql

@@ -8,6 +8,7 @@
  * @precision high
  * @id cpp/cleartext-storage-file
  * @tags security
+ *       external/cwe/cwe-260
  *       external/cwe/cwe-313
  */
 

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-457/InitializationFunctions.qll

@@ -84,8 +84,8 @@ class ParameterNullCheck extends ParameterCheck {
     p.getFunction() instanceof InitializationFunction and
     p.getType().getUnspecifiedType() instanceof PointerType and
     exists(VariableAccess va | va = p.getAnAccess() |
-      nullSuccessor = getATrueSuccessor() and
-      notNullSuccessor = getAFalseSuccessor() and
+      nullSuccessor = this.getATrueSuccessor() and
+      notNullSuccessor = this.getAFalseSuccessor() and
       (
         va = this.(NotExpr).getOperand() or
         va = any(EQExpr eq | eq = this and eq.getAnOperand().getValue() = "0").getAnOperand() or
@@ -95,8 +95,8 @@ class ParameterNullCheck extends ParameterCheck {
               .getAnOperand()
       )
       or
-      nullSuccessor = getAFalseSuccessor() and
-      notNullSuccessor = getATrueSuccessor() and
+      nullSuccessor = this.getAFalseSuccessor() and
+      notNullSuccessor = this.getATrueSuccessor() and
       (
         va = this or
         va = any(NEExpr eq | eq = this and eq.getAnOperand().getValue() = "0").getAnOperand() or
@@ -132,7 +132,7 @@ class ValidatedExternalCondInitFunction extends ExternalData {
   ValidatedExternalCondInitFunction() { this.getDataPath().matches("%cond-init%.csv") }
 
   predicate isExternallyVerified(Function f, int param) {
-    functionSignature(f, getField(1), getField(2)) and param = getFieldAsInt(3)
+    functionSignature(f, this.getField(1), this.getField(2)) and param = this.getFieldAsInt(3)
   }
 }
 
@@ -193,7 +193,7 @@ class InitializationFunction extends Function {
             .getAnOverridingFunction+()
             .(InitializationFunction)
             .initializedParameter() or
-      getParameter(i) = any(InitializationFunctionCall c).getAnInitParameter()
+      this.getParameter(i) = any(InitializationFunctionCall c).getAnInitParameter()
     )
     or
     // If we have no definition, we look at SAL annotations
@@ -227,7 +227,7 @@ class InitializationFunction extends Function {
         result = getAnInitializedArgument(any(Call c))
         or
         exists(IfStmt check | result = check.getCondition().getAChild*() |
-          paramReassignmentCondition(check)
+          this.paramReassignmentCondition(check)
         )
       )
       or
@@ -249,15 +249,15 @@ class InitializationFunction extends Function {
 
   /** Holds if `n` can be reached without the parameter at `index` being reassigned. */
   predicate paramNotReassignedAt(ControlFlowNode n, int index, Context c) {
-    c = getAContext(index) and
+    c = this.getAContext(index) and
     (
       not exists(this.getEntryPoint()) and index = i and n = this
       or
       n = this.getEntryPoint() and index = i
       or
-      exists(ControlFlowNode mid | paramNotReassignedAt(mid, index, c) |
+      exists(ControlFlowNode mid | this.paramNotReassignedAt(mid, index, c) |
         n = mid.getASuccessor() and
-        not n = paramReassignment(index) and
+        not n = this.paramReassignment(index) and
         /*
          * Ignore successor edges where the parameter is null, because it is then confirmed to be
          * initialized.
@@ -265,7 +265,7 @@ class InitializationFunction extends Function {
 
         not exists(ParameterNullCheck nullCheck |
           nullCheck = mid and
-          nullCheck = getANullCheck(index) and
+          nullCheck = this.getANullCheck(index) and
           n = nullCheck.getNullSuccessor()
         ) and
         /*
@@ -281,13 +281,13 @@ class InitializationFunction extends Function {
 
   /** Gets a null-check on the parameter at `index`. */
   private ParameterNullCheck getANullCheck(int index) {
-    getParameter(index) = result.getParameter()
+    this.getParameter(index) = result.getParameter()
   }
 
   /** Gets a parameter which is not at the given index. */
   private Parameter getOtherParameter(int index) {
     index = i and
-    result = getAParameter() and
+    result = this.getAParameter() and
     not result.getIndex() = index
   }
 
@@ -306,10 +306,10 @@ class InitializationFunction extends Function {
     if
       strictcount(Parameter p |
         exists(Context c | c = ParamNull(p) or c = ParamNotNull(p)) and
-        p = getOtherParameter(index)
+        p = this.getOtherParameter(index)
       ) = 1
     then
-      exists(Parameter p | p = getOtherParameter(index) |
+      exists(Parameter p | p = this.getOtherParameter(index) |
         result = ParamNull(p) or result = ParamNotNull(p)
       )
     else
@@ -424,8 +424,8 @@ class ConditionalInitializationCall extends FunctionCall {
 
   /** Gets the argument passed for the given parameter to this call. */
   Expr getArgumentForParameter(Parameter p) {
-    p = getTarget().getAParameter() and
-    result = getArgument(p.getIndex())
+    p = this.getTarget().getAParameter() and
+    result = this.getArgument(p.getIndex())
   }
 
   /**
@@ -442,7 +442,7 @@ class ConditionalInitializationCall extends FunctionCall {
         context = ParamNotNull(otherP) or
         context = ParamNull(otherP)
       |
-        otherArg = getArgumentForParameter(otherP) and
+        otherArg = this.getArgumentForParameter(otherP) and
         (otherArg instanceof AddressOfExpr implies context = ParamNotNull(otherP)) and
         (otherArg.getType() instanceof ArrayType implies context = ParamNotNull(otherP)) and
         (otherArg.getValue() = "0" implies context = ParamNull(otherP))
@@ -511,8 +511,8 @@ class ConditionalInitializationCall extends FunctionCall {
         )
     )
     or
-    exists(ControlFlowNode mid | mid = uncheckedReaches(var) |
-      not mid = getStatusVariable().getAnAccess() and
+    exists(ControlFlowNode mid | mid = this.uncheckedReaches(var) |
+      not mid = this.getStatusVariable().getAnAccess() and
       not mid = var.getAnAccess() and
       not exists(VariableAccess write | result = write and write = var.getAnAccess() |
         write = any(AssignExpr a).getLValue() or

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-457/UninitializedVariables.qll

@@ -44,7 +44,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     // Find a call that conditionally initializes this variable
     hasConditionalInitialization(f, call, this, initAccess, e) and
     // Ignore cases where the variable is assigned prior to the call
-    not reaches(getAnAssignedValue(), initAccess) and
+    not reaches(this.getAnAssignedValue(), initAccess) and
     // Ignore cases where the variable is assigned field-wise prior to the call.
     not exists(FieldAccess fa |
       exists(Assignment a |
@@ -56,7 +56,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     ) and
     // Ignore cases where the variable is assigned by a prior call to an initialization function
     not exists(Call c |
-      getAnAccess() = getAnInitializedArgument(c).(AddressOfExpr).getOperand() and
+      this.getAnAccess() = getAnInitializedArgument(c).(AddressOfExpr).getOperand() and
       reaches(c, initAccess)
     ) and
     /*
@@ -64,7 +64,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
      * the CFG, but should always be considered as initialized, so exclude them.
      */
 
-    not exists(getInitializer().getExpr())
+    not exists(this.getInitializer().getExpr())
   }
 
   /**
@@ -90,7 +90,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     // Variable associated with this particular call
     call = initializingCall and
     // Access is a meaningful read access
-    result = getAReadAccess() and
+    result = this.getAReadAccess() and
     // Which occurs after the call
     reaches(call, result) and
     /*
@@ -124,7 +124,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     call = initializingCall and
     initializingFunction = f and
     e = evidence and
-    result = getAReadAccessAfterCall(initializingCall) and
+    result = this.getAReadAccessAfterCall(initializingCall) and
     (
       // Access is risky because status return code ignored completely
       call instanceof ExprInVoidContext
@@ -148,7 +148,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     call = initializingCall and
     initializingFunction = f and
     e = evidence and
-    result = getAReadAccessAfterCall(initializingCall) and
+    result = this.getAReadAccessAfterCall(initializingCall) and
     exists(LocalVariable status, Assignment a |
       a.getRValue() = call and
       call = status.getAnAssignedValue() and
@@ -184,7 +184,7 @@ class ConditionallyInitializedVariable extends LocalVariable {
     ConditionalInitializationFunction initializingFunction,
     ConditionalInitializationCall initializingCall, Evidence evidence
   ) {
-    result = getARiskyAccessBeforeStatusCheck(initializingFunction, initializingCall, evidence) or
-    result = getARiskyAccessWithNoStatusCheck(initializingFunction, initializingCall, evidence)
+    result = this.getARiskyAccessBeforeStatusCheck(initializingFunction, initializingCall, evidence) or
+    result = this.getARiskyAccessWithNoStatusCheck(initializingFunction, initializingCall, evidence)
   }
 }

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-497/ExposedSystemData.ql

@@ -31,15 +31,15 @@ abstract class SystemData extends Element {
    */
   Expr getAnExprIndirect() {
     // direct SystemData
-    result = getAnExpr() or
+    result = this.getAnExpr() or
     // flow via global or member variable (conservative approximation)
-    result = getAnAffectedVar().getAnAccess() or
+    result = this.getAnAffectedVar().getAnAccess() or
     // flow via stack variable
-    definitionUsePair(_, getAnExprIndirect(), result) or
-    useUsePair(_, getAnExprIndirect(), result) or
-    useUsePair(_, result, getAnExprIndirect()) or
+    definitionUsePair(_, this.getAnExprIndirect(), result) or
+    useUsePair(_, this.getAnExprIndirect(), result) or
+    useUsePair(_, result, this.getAnExprIndirect()) or
     // flow from assigned value to assignment expression
-    result.(AssignExpr).getRValue() = getAnExprIndirect()
+    result.(AssignExpr).getRValue() = this.getAnExprIndirect()
   }
 
   /**

repo-tests/codeql/cpp/ql/src/Security/CWE/CWE-676/DangerousUseOfCin.ql

@@ -67,16 +67,16 @@ class IFStream extends Type {
  */
 class CinVariable extends NamespaceVariable {
   CinVariable() {
-    getName() = ["cin", "wcin"] and
-    getNamespace().getName() = "std"
+    this.getName() = ["cin", "wcin"] and
+    this.getNamespace().getName() = "std"
   }
 }
 
 /** A call to `std::operator>>`. */
 class OperatorRShiftCall extends FunctionCall {
   OperatorRShiftCall() {
-    getTarget().getNamespace().getName() = "std" and
-    getTarget().hasName("operator>>")
+    this.getTarget().getNamespace().getName() = "std" and
+    this.getTarget().hasName("operator>>")
   }
 
   /*
@@ -87,15 +87,15 @@ class OperatorRShiftCall extends FunctionCall {
    */
 
   Expr getSource() {
-    if getTarget() instanceof MemberFunction
-    then result = getQualifier()
-    else result = getArgument(0)
+    if this.getTarget() instanceof MemberFunction
+    then result = this.getQualifier()
+    else result = this.getArgument(0)
   }
 
   Expr getDest() {
-    if getTarget() instanceof MemberFunction
-    then result = getArgument(0)
-    else result = getArgument(1)
+    if this.getTarget() instanceof MemberFunction
+    then result = this.getArgument(0)
+    else result = this.getArgument(1)
   }
 }
 
@@ -119,7 +119,7 @@ abstract class PotentiallyDangerousInput extends Expr {
    * Gets the width restriction that applies to the input stream
    * for this expression, if any.
    */
-  Expr getWidth() { result = getPreviousAccess().getWidthAfter() }
+  Expr getWidth() { result = this.getPreviousAccess().getWidthAfter() }
 
   private Expr getWidthSetHere() {
     exists(FunctionCall widthCall |
@@ -154,11 +154,11 @@ abstract class PotentiallyDangerousInput extends Expr {
    * after this expression, if any.
    */
   Expr getWidthAfter() {
-    result = getWidthSetHere()
+    result = this.getWidthSetHere()
     or
-    not exists(getWidthSetHere()) and
-    not isWidthConsumedHere() and
-    result = getWidth()
+    not exists(this.getWidthSetHere()) and
+    not this.isWidthConsumedHere() and
+    result = this.getWidth()
   }
 }
 

repo-tests/codeql/cpp/ql/src/experimental/Security/CWE/CWE-273/PrivilegeDroppingOutoforder.ql

@@ -21,9 +21,9 @@ predicate argumentMayBeRoot(Expr e) {
 
 class SetuidLikeFunctionCall extends FunctionCall {
   SetuidLikeFunctionCall() {
-    (getTarget().hasGlobalName("setuid") or getTarget().hasGlobalName("setresuid")) and
+    (this.getTarget().hasGlobalName("setuid") or this.getTarget().hasGlobalName("setresuid")) and
     // setuid/setresuid with the root user are false positives.
-    not argumentMayBeRoot(getArgument(0))
+    not argumentMayBeRoot(this.getArgument(0))
   }
 }
 
@@ -44,7 +44,7 @@ class SetuidLikeWrapperCall extends FunctionCall {
 
 class CallBeforeSetuidFunctionCall extends FunctionCall {
   CallBeforeSetuidFunctionCall() {
-    getTarget()
+    this.getTarget()
         .hasGlobalName([
             "setgid", "setresgid",
             // Compatibility may require skipping initgroups and setgroups return checks.
@@ -52,7 +52,7 @@ class CallBeforeSetuidFunctionCall extends FunctionCall {
             "initgroups", "setgroups"
           ]) and
     // setgid/setresgid/etc with the root group are false positives.
-    not argumentMayBeRoot(getArgument(0))
+    not argumentMayBeRoot(this.getArgument(0))
   }
 }
 

repo-tests/codeql/cpp/ql/src/experimental/Security/CWE/CWE-401/MemoryLeakOnFailedCallToRealloc.ql

@@ -24,7 +24,7 @@ class CallMayNotReturn extends FunctionCall {
     not exists(this.(ControlFlowNode).getASuccessor())
     or
     // call to another function that may not return
-    exists(CallMayNotReturn exit | getTarget() = exit.getEnclosingFunction())
+    exists(CallMayNotReturn exit | this.getTarget() = exit.getEnclosingFunction())
   }
 }
 

repo-tests/codeql/cpp/ql/src/experimental/Security/CWE/CWE-703/FindIncorrectlyUsedExceptions.ql

@@ -38,13 +38,7 @@ where
     fc.getTargetType().(Class).getABaseClass+().hasGlobalOrStdName("exception") or
     fc.getTargetType().(Class).getABaseClass+().hasGlobalOrStdName("CException")
   ) and
+  fc instanceof ExprInVoidContext and
   not fc.isInMacroExpansion() and
-  not exists(ThrowExpr texp | fc.getEnclosingStmt() = texp.getEnclosingStmt()) and
-  not exists(FunctionCall fctmp | fctmp.getAnArgument() = fc) and
-  not fc instanceof ConstructorDirectInit and
-  not fc.getEnclosingStmt() instanceof DeclStmt and
-  not fc instanceof ConstructorDelegationInit and
-  not fc.getParent() instanceof Initializer and
-  not fc.getParent() instanceof AllocationExpr and
-  msg = "This object does not generate an exception."
+  msg = "Object creation of exception type on stack. Did you forget the throw keyword?"
 select fc, msg

repo-tests/codeql/cpp/ql/src/jsf/4.10 Classes/AV Rule 79.ql

@@ -118,7 +118,7 @@ private predicate exprReleases(Expr e, Expr released, string kind) {
 }
 
 class Resource extends MemberVariable {
-  Resource() { not isStatic() }
+  Resource() { not this.isStatic() }
 
   // Check that an expr is somewhere in this class - does not have to be a constructor
   predicate inSameClass(Expr e) {
@@ -129,7 +129,7 @@ class Resource extends MemberVariable {
     f instanceof Destructor and f.getDeclaringType() = this.getDeclaringType()
     or
     exists(Function mid, FunctionCall fc |
-      calledFromDestructor(mid) and
+      this.calledFromDestructor(mid) and
       fc.getEnclosingFunction() = mid and
       fc.getTarget() = f and
       f.getDeclaringType() = this.getDeclaringType()
@@ -137,7 +137,7 @@ class Resource extends MemberVariable {
   }
 
   predicate inDestructor(Expr e) {
-    exists(Function f | f = e.getEnclosingFunction() | calledFromDestructor(f))
+    exists(Function f | f = e.getEnclosingFunction() | this.calledFromDestructor(f))
   }
 
   predicate acquisitionWithRequiredKind(Assignment acquireAssign, string kind) {

repo-tests/codeql/csharp/ql/consistency-queries/SsaConsistency.ql

@@ -0,0 +1,10 @@
+import csharp
+import semmle.code.csharp.dataflow.internal.SsaImplCommon::Consistency
+
+class MyRelevantDefinition extends RelevantDefinition, Ssa::Definition {
+  override predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    this.getLocation().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+  }
+}

repo-tests/codeql/csharp/ql/lib/semmle/code/cil/internal/SsaImplCommon.qll

@@ -634,3 +634,29 @@ class UncertainWriteDefinition extends WriteDefinition {
     )
   }
 }
+
+/** Provides a set of consistency queries. */
+module Consistency {
+  abstract class RelevantDefinition extends Definition {
+    abstract predicate hasLocationInfo(
+      string filepath, int startline, int startcolumn, int endline, int endcolumn
+    );
+  }
+
+  query predicate nonUniqueDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    ssaDefReachesRead(v, def, bb, i) and
+    not exists(unique(Definition def0 | ssaDefReachesRead(v, def0, bb, i)))
+  }
+
+  query predicate readWithoutDef(SourceVariable v, BasicBlock bb, int i) {
+    variableRead(bb, i, v, _) and
+    not ssaDefReachesRead(v, _, bb, i)
+  }
+
+  query predicate deadDef(RelevantDefinition def, SourceVariable v) {
+    v = def.getSourceVariable() and
+    not ssaDefReachesRead(_, def, _, _) and
+    not phiHasInputFromBlock(_, def, _) and
+    not uncertainWriteDefinitionInput(_, def)
+  }
+}

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/ExprOrStmtParent.qll

@@ -140,7 +140,9 @@ private module Cached {
   }
 
   private Expr getAChildExpr(ExprOrStmtParent parent) {
-    result = parent.getAChildExpr() or
+    result = parent.getAChildExpr() and
+    not result = parent.(DeclarationWithGetSetAccessors).getExpressionBody()
+    or
     result = parent.(AssignOperation).getExpandedAssignment()
   }
 
@@ -159,7 +161,7 @@ private module Cached {
 
   private predicate parent(ControlFlowElement child, ExprOrStmtParent parent) {
     child = getAChild(parent) and
-    not child instanceof Callable
+    not child = any(Callable c).getBody()
   }
 
   /** Holds if the enclosing body of `cfe` is `body`. */

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/Member.qll

@@ -383,7 +383,7 @@ class Parameterizable extends DotNet::Parameterizable, Declaration, @parameteriz
   override Parameter getParameter(int i) { params(result, _, _, i, _, this, _) }
 
   /**
-   * Gets the name of this parameter followed by its type, possibly prefixed
+   * Gets the type of the parameter, possibly prefixed
    * with `out`, `ref`, or `params`, where appropriate.
    */
   private string parameterTypeToString(int i) {

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/controlflow/ControlFlowGraph.qll

@@ -25,7 +25,7 @@ module ControlFlow {
    * Only nodes that can be reached from the callable entry point are included in
    * the CFG.
    */
-  class Node extends TNode {
+  class Node extends TCfgNode {
     /** Gets a textual representation of this control flow node. */
     string toString() { none() }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraphImplShared.qll

@@ -788,7 +788,7 @@ private module Cached {
    * The control flow graph is pruned for unreachable nodes.
    */
   cached
-  newtype TNode =
+  newtype TCfgNode =
     TEntryNode(CfgScope scope) { succEntrySplits(scope, _, _, _) } or
     TAnnotatedExitNode(CfgScope scope, boolean normal) {
       exists(Reachability::SameSplitsBlock b, SuccessorType t | b.isReachable(_) |
@@ -807,7 +807,7 @@ private module Cached {
 
   /** Gets a successor node of a given flow type, if any. */
   cached
-  TNode getASuccessor(TNode pred, SuccessorType t) {
+  TCfgNode getASuccessor(TCfgNode pred, SuccessorType t) {
     // Callable entry node -> callable body
     exists(ControlFlowElement succElement, Splits succSplits, CfgScope scope |
       result = TElementNode(succElement, succSplits) and
@@ -943,4 +943,9 @@ module Consistency {
     strictcount(getASuccessor(node, t)) > 1 and
     successor = getASuccessor(node, t)
   }
+
+  query predicate deadEnd(Node node) {
+    not node instanceof TExitNode and
+    not exists(getASuccessor(node, _))
+  }
 }

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/controlflow/internal/pressa/SsaImplCommon.qll

@@ -634,3 +634,29 @@ class UncertainWriteDefinition extends WriteDefinition {
     )
   }
 }
+
+/** Provides a set of consistency queries. */
+module Consistency {
+  abstract class RelevantDefinition extends Definition {
+    abstract predicate hasLocationInfo(
+      string filepath, int startline, int startcolumn, int endline, int endcolumn
+    );
+  }
+
+  query predicate nonUniqueDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    ssaDefReachesRead(v, def, bb, i) and
+    not exists(unique(Definition def0 | ssaDefReachesRead(v, def0, bb, i)))
+  }
+
+  query predicate readWithoutDef(SourceVariable v, BasicBlock bb, int i) {
+    variableRead(bb, i, v, _) and
+    not ssaDefReachesRead(v, _, bb, i)
+  }
+
+  query predicate deadDef(RelevantDefinition def, SourceVariable v) {
+    v = def.getSourceVariable() and
+    not ssaDefReachesRead(_, def, _, _) and
+    not phiHasInputFromBlock(_, def, _) and
+    not uncertainWriteDefinitionInput(_, def)
+  }
+}

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/ExternalFlow.qll

@@ -78,6 +78,7 @@ private import internal.DataFlowPublic
 private import internal.FlowSummaryImpl::Public
 private import internal.FlowSummaryImpl::Private::External
 private import internal.FlowSummaryImplSpecific
+private import semmle.code.csharp.dispatch.OverridableCallable
 
 /**
  * A module importing the frameworks that provide external flow data,
@@ -347,12 +348,15 @@ private class UnboundValueOrRefType extends ValueOrRefType {
   }
 }
 
-private class UnboundCallable extends Callable, Virtualizable {
+private class UnboundCallable extends Callable {
   UnboundCallable() { this.isUnboundDeclaration() }
 
   predicate overridesOrImplementsUnbound(UnboundCallable that) {
     exists(Callable c |
-      this.overridesOrImplementsOrEquals(c) and
+      this.(Virtualizable).overridesOrImplementsOrEquals(c) or
+      this = c.(OverridableCallable).getAnUltimateImplementor() or
+      this = c.(OverridableCallable).getAnOverrider+()
+    |
       this != c and
       that = c.getUnboundDeclaration()
     )
@@ -409,7 +413,7 @@ private Element interpretElement0(
   string namespace, string type, boolean subtypes, string name, string signature
 ) {
   exists(UnboundValueOrRefType t | elementSpec(namespace, type, subtypes, name, signature, _, t) |
-    exists(Member m |
+    exists(Declaration m |
       (
         result = m
         or

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/LibraryTypeDataFlow.qll

@@ -499,82 +499,6 @@ private module FrameworkDataFlowAdaptor {
   }
 }
 
-/** Data flow for `System.Boolean`. */
-class SystemBooleanFlow extends LibraryTypeDataFlow, SystemBooleanStruct {
-  override predicate callableFlow(
-    CallableFlowSource source, CallableFlowSink sink, SourceDeclarationCallable c,
-    boolean preservesValue
-  ) {
-    this.methodFlow(source, sink, c) and
-    preservesValue = false
-  }
-
-  private predicate methodFlow(
-    CallableFlowSource source, CallableFlowSink sink, SourceDeclarationMethod m
-  ) {
-    m = this.getParseMethod() and
-    (
-      source = TCallableFlowSourceArg(0) and
-      sink = TCallableFlowSinkReturn()
-    )
-    or
-    m = this.getTryParseMethod() and
-    (
-      source = TCallableFlowSourceArg(0) and
-      (
-        sink = TCallableFlowSinkReturn()
-        or
-        sink = TCallableFlowSinkArg(any(int i | m.getParameter(i).isOutOrRef()))
-      )
-    )
-  }
-}
-
-/** Data flow for `System.Uri`. */
-class SystemUriFlow extends LibraryTypeDataFlow, SystemUriClass {
-  override predicate callableFlow(
-    CallableFlowSource source, CallableFlowSink sink, SourceDeclarationCallable c,
-    boolean preservesValue
-  ) {
-    (
-      this.constructorFlow(source, sink, c)
-      or
-      this.methodFlow(source, sink, c)
-      or
-      exists(Property p |
-        this.propertyFlow(p) and
-        source = TCallableFlowSourceQualifier() and
-        sink = TCallableFlowSinkReturn() and
-        c = p.getGetter()
-      )
-    ) and
-    preservesValue = false
-  }
-
-  private predicate constructorFlow(CallableFlowSource source, CallableFlowSink sink, Constructor c) {
-    c = this.getAMember() and
-    c.getParameter(0).getType() instanceof StringType and
-    source = TCallableFlowSourceArg(0) and
-    sink = TCallableFlowSinkReturn()
-  }
-
-  private predicate methodFlow(
-    CallableFlowSource source, CallableFlowSink sink, SourceDeclarationMethod m
-  ) {
-    m = this.getAMethod("ToString") and
-    source = TCallableFlowSourceQualifier() and
-    sink = TCallableFlowSinkReturn()
-  }
-
-  private predicate propertyFlow(Property p) {
-    p = this.getPathAndQueryProperty()
-    or
-    p = this.getQueryProperty()
-    or
-    p = this.getOriginalStringProperty()
-  }
-}
-
 /** Data flow for `System.IO.StringReader`. */
 class SystemIOStringReaderFlow extends LibraryTypeDataFlow, SystemIOStringReaderClass {
   override predicate callableFlow(

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl2.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl3.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl4.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl5.qll

@@ -289,6 +289,7 @@ private predicate outBarrier(NodeEx node, Configuration config) {
   )
 }
 
+pragma[nomagic]
 private predicate fullBarrier(NodeEx node, Configuration config) {
   exists(Node n | node.asNode() = n |
     config.isBarrier(n)
@@ -307,11 +308,23 @@ private predicate fullBarrier(NodeEx node, Configuration config) {
 }
 
 pragma[nomagic]
-private predicate sourceNode(NodeEx node, Configuration config) { config.isSource(node.asNode()) }
+private predicate sourceNode(NodeEx node, Configuration config) {
+  config.isSource(node.asNode()) and
+  not fullBarrier(node, config)
+}
 
 pragma[nomagic]
 private predicate sinkNode(NodeEx node, Configuration config) { config.isSink(node.asNode()) }
 
+/** Provides the relevant barriers for a step from `node1` to `node2`. */
+pragma[inline]
+private predicate stepFilter(NodeEx node1, NodeEx node2, Configuration config) {
+  not outBarrier(node1, config) and
+  not inBarrier(node2, config) and
+  not fullBarrier(node1, config) and
+  not fullBarrier(node2, config)
+}
+
 /**
  * Holds if data can flow in one local step from `node1` to `node2`.
  */
@@ -320,16 +333,14 @@ private predicate localFlowStep(NodeEx node1, NodeEx node2, Configuration config
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     simpleLocalFlowStepExt(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.asNode() = n and
-    node2.isImplicitReadNode(n, false)
+    node2.isImplicitReadNode(n, false) and
+    not fullBarrier(node1, config)
   )
 }
 
@@ -342,16 +353,14 @@ private predicate additionalLocalFlowStep(NodeEx node1, NodeEx node2, Configurat
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) = getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config)
+    stepFilter(node1, node2, config)
   )
   or
   exists(Node n |
     config.allowImplicitRead(n, _) and
     node1.isImplicitReadNode(n, true) and
-    node2.asNode() = n
+    node2.asNode() = n and
+    not fullBarrier(node2, config)
   )
 }
 
@@ -363,10 +372,7 @@ private predicate jumpStep(NodeEx node1, NodeEx node2, Configuration config) {
     node1.asNode() = n1 and
     node2.asNode() = n2 and
     jumpStepCached(n1, n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
@@ -380,16 +386,14 @@ private predicate additionalJumpStep(NodeEx node1, NodeEx node2, Configuration c
     node2.asNode() = n2 and
     config.isAdditionalFlowStep(n1, n2) and
     getNodeEnclosingCallable(n1) != getNodeEnclosingCallable(n2) and
-    not outBarrier(node1, config) and
-    not inBarrier(node2, config) and
-    not fullBarrier(node1, config) and
-    not fullBarrier(node2, config) and
+    stepFilter(node1, node2, config) and
     not config.getAFeature() instanceof FeatureEqualSourceSinkCallContext
   )
 }
 
 private predicate read(NodeEx node1, Content c, NodeEx node2, Configuration config) {
-  read(node1.asNode(), c, node2.asNode())
+  read(node1.asNode(), c, node2.asNode()) and
+  stepFilter(node1, node2, config)
   or
   exists(Node n |
     node2.isImplicitReadNode(n, true) and
@@ -402,7 +406,8 @@ private predicate store(
   NodeEx node1, TypedContent tc, NodeEx node2, DataFlowType contentType, Configuration config
 ) {
   store(node1.asNode(), tc, node2.asNode(), contentType) and
-  read(_, tc.getContent(), _, config)
+  read(_, tc.getContent(), _, config) and
+  stepFilter(node1, node2, config)
 }
 
 pragma[nomagic]
@@ -451,63 +456,59 @@ private module Stage1 {
    * argument in a call.
    */
   predicate fwdFlow(NodeEx node, Cc cc, Configuration config) {
-    not fullBarrier(node, config) and
-    (
-      sourceNode(node, config) and
-      if hasSourceCallCtx(config) then cc = true else cc = false
+    sourceNode(node, config) and
+    if hasSourceCallCtx(config) then cc = true else cc = false
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      localFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, cc, config) and
+      additionalLocalFlowStep(mid, node, config)
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      jumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    exists(NodeEx mid |
+      fwdFlow(mid, _, config) and
+      additionalJumpStep(mid, node, config) and
+      cc = false
+    )
+    or
+    // store
+    exists(NodeEx mid |
+      useFieldFlow(config) and
+      fwdFlow(mid, cc, config) and
+      store(mid, _, node, _, config)
+    )
+    or
+    // read
+    exists(Content c |
+      fwdFlowRead(c, node, cc, config) and
+      fwdFlowConsCand(c, config)
+    )
+    or
+    // flow into a callable
+    exists(NodeEx arg |
+      fwdFlow(arg, _, config) and
+      viableParamArgEx(_, node, arg) and
+      cc = true and
+      not fullBarrier(node, config)
+    )
+    or
+    // flow out of a callable
+    exists(DataFlowCall call |
+      fwdFlowOut(call, node, false, config) and
+      cc = false
       or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        localFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, cc, config) and
-        additionalLocalFlowStep(mid, node, config)
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        jumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      exists(NodeEx mid |
-        fwdFlow(mid, _, config) and
-        additionalJumpStep(mid, node, config) and
-        cc = false
-      )
-      or
-      // store
-      exists(NodeEx mid |
-        useFieldFlow(config) and
-        fwdFlow(mid, cc, config) and
-        store(mid, _, node, _, config) and
-        not outBarrier(mid, config)
-      )
-      or
-      // read
-      exists(Content c |
-        fwdFlowRead(c, node, cc, config) and
-        fwdFlowConsCand(c, config) and
-        not inBarrier(node, config)
-      )
-      or
-      // flow into a callable
-      exists(NodeEx arg |
-        fwdFlow(arg, _, config) and
-        viableParamArgEx(_, node, arg) and
-        cc = true
-      )
-      or
-      // flow out of a callable
-      exists(DataFlowCall call |
-        fwdFlowOut(call, node, false, config) and
-        cc = false
-        or
-        fwdFlowOutFromArg(call, node, config) and
-        fwdFlowIsEntered(call, cc, config)
-      )
+      fwdFlowOutFromArg(call, node, config) and
+      fwdFlowIsEntered(call, cc, config)
     )
   }
 
@@ -547,7 +548,8 @@ private module Stage1 {
   private predicate fwdFlowOut(DataFlowCall call, NodeEx out, Cc cc, Configuration config) {
     exists(ReturnPosition pos |
       fwdFlowReturnPosition(pos, cc, config) and
-      viableReturnPosOutEx(call, pos, out)
+      viableReturnPosOutEx(call, pos, out) and
+      not fullBarrier(out, config)
     )
   }
 
@@ -773,6 +775,7 @@ private module Stage1 {
    * Holds if flow may enter through `p` and reach a return node making `p` a
    * candidate for the origin of a summary.
    */
+  pragma[nomagic]
   predicate parameterMayFlowThrough(ParamNodeEx p, DataFlowCallable c, Ap ap, Configuration config) {
     exists(ReturnKindExt kind |
       throughFlowNodeCand(p, config) and
@@ -1009,6 +1012,9 @@ private module Stage2 {
 
   private predicate flowIntoCall = flowIntoCallNodeCand1/5;
 
+  bindingset[node, ap]
+  private predicate filter(NodeEx node, Ap ap) { any() }
+
   bindingset[ap, contentType]
   private predicate typecheckStore(Ap ap, DataFlowType contentType) { any() }
 
@@ -1017,14 +1023,23 @@ private module Stage2 {
     PrevStage::revFlow(node, _, _, apa, config)
   }
 
+  bindingset[result, apa]
+  private ApApprox unbindApa(ApApprox apa) {
+    exists(ApApprox apa0 |
+      apa = pragma[only_bind_into](apa0) and result = pragma[only_bind_into](apa0)
+    )
+  }
+
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1037,6 +1052,13 @@ private module Stage2 {
    */
   pragma[nomagic]
   predicate fwdFlow(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
+    fwdFlow0(node, cc, argAp, ap, config) and
+    flowCand(node, unbindApa(getApprox(ap)), config) and
+    filter(node, ap)
+  }
+
+  pragma[nomagic]
+  private predicate fwdFlow0(NodeEx node, Cc cc, ApOption argAp, Ap ap, Configuration config) {
     flowCand(node, _, config) and
     sourceNode(node, config) and
     (if hasSourceCallCtx(config) then cc = ccSomeCall() else cc = ccNone()) and
@@ -1107,7 +1129,7 @@ private module Stage2 {
   ) {
     exists(DataFlowType contentType |
       fwdFlow(node1, cc, argAp, ap1, config) and
-      PrevStage::storeStepCand(node1, getApprox(ap1), tc, node2, contentType, config) and
+      PrevStage::storeStepCand(node1, unbindApa(getApprox(ap1)), tc, node2, contentType, config) and
       typecheckStore(ap1, contentType)
     )
   }
@@ -1142,9 +1164,8 @@ private module Stage2 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1159,9 +1180,8 @@ private module Stage2 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1171,10 +1191,8 @@ private module Stage2 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1188,7 +1206,7 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p |
       fwdFlowIn(call, p, cc, _, argAp, ap, config) and
-      PrevStage::parameterMayFlowThrough(p, _, getApprox(ap), config)
+      PrevStage::parameterMayFlowThrough(p, _, unbindApa(getApprox(ap)), config)
     )
   }
 
@@ -1230,6 +1248,11 @@ private module Stage2 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -1306,7 +1329,7 @@ private module Stage2 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -1341,9 +1364,8 @@ private module Stage2 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1353,9 +1375,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1365,9 +1386,8 @@ private module Stage2 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1707,12 +1727,14 @@ private module Stage3 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -1837,9 +1859,8 @@ private module Stage3 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1854,9 +1875,8 @@ private module Stage3 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1866,10 +1886,8 @@ private module Stage3 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -1925,6 +1943,11 @@ private module Stage3 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2001,7 +2024,7 @@ private module Stage3 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2036,9 +2059,8 @@ private module Stage3 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2048,9 +2070,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2060,9 +2081,8 @@ private module Stage3 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2473,12 +2493,14 @@ private module Stage4 {
 
   pragma[nomagic]
   private predicate flowThroughOutOfCall(
-    DataFlowCall call, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow, Configuration config
+    DataFlowCall call, CcCall ccc, RetNodeEx ret, NodeEx out, boolean allowsFieldFlow,
+    Configuration config
   ) {
     flowOutOfCall(call, ret, out, allowsFieldFlow, pragma[only_bind_into](config)) and
     PrevStage::callMayFlowThroughRev(call, pragma[only_bind_into](config)) and
     PrevStage::parameterMayFlowThrough(_, ret.getEnclosingCallable(), _,
-      pragma[only_bind_into](config))
+      pragma[only_bind_into](config)) and
+    ccc.matchesCall(call)
   }
 
   /**
@@ -2603,9 +2625,8 @@ private module Stage4 {
     exists(ArgNodeEx arg, boolean allowsFieldFlow |
       fwdFlow(arg, outercc, argAp, ap, config) and
       flowIntoCall(call, arg, p, allowsFieldFlow, config) and
-      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      innercc = getCallContextCall(call, p.getEnclosingCallable(), outercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2620,9 +2641,8 @@ private module Stage4 {
       fwdFlow(ret, innercc, argAp, ap, config) and
       flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
       inner = ret.getEnclosingCallable() and
-      ccOut = getCallContextReturn(inner, call, innercc)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      ccOut = getCallContextReturn(inner, call, innercc) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2632,10 +2652,8 @@ private module Stage4 {
   ) {
     exists(RetNodeEx ret, boolean allowsFieldFlow, CcCall ccc |
       fwdFlow(ret, ccc, apSome(argAp), ap, config) and
-      flowThroughOutOfCall(call, ret, out, allowsFieldFlow, config) and
-      ccc.matchesCall(call)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughOutOfCall(call, ccc, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2691,6 +2709,11 @@ private module Stage4 {
     callMayFlowThroughFwd(call, pragma[only_bind_into](config))
   }
 
+  pragma[nomagic]
+  private predicate returnNodeMayFlowThrough(RetNodeEx ret, Ap ap, Configuration config) {
+    fwdFlow(ret, any(CcCall ccc), apSome(_), ap, config)
+  }
+
   /**
    * Holds if `node` with access path `ap` is part of a path from a source to a
    * sink in the configuration `config`.
@@ -2767,7 +2790,7 @@ private module Stage4 {
     // flow out of a callable
     revFlowOut(_, node, _, _, ap, config) and
     toReturn = true and
-    if fwdFlow(node, any(CcCall ccc), apSome(_), ap, config)
+    if returnNodeMayFlowThrough(node, ap, config)
     then returnAp = apSome(ap)
     else returnAp = apNone()
   }
@@ -2802,9 +2825,8 @@ private module Stage4 {
   ) {
     exists(NodeEx out, boolean allowsFieldFlow |
       revFlow(out, toReturn, returnAp, ap, config) and
-      flowOutOfCall(call, ret, out, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowOutOfCall(call, ret, out, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2814,9 +2836,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, false, returnAp, ap, config) and
-      flowIntoCall(_, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowIntoCall(_, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 
@@ -2826,9 +2847,8 @@ private module Stage4 {
   ) {
     exists(ParamNodeEx p, boolean allowsFieldFlow |
       revFlow(p, true, apSome(returnAp), ap, config) and
-      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config)
-    |
-      ap instanceof ApNil or allowsFieldFlow = true
+      flowThroughIntoCall(call, arg, p, allowsFieldFlow, config) and
+      if allowsFieldFlow = false then ap instanceof ApNil else any()
     )
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImplConsistency.qll

@@ -9,6 +9,19 @@ private import tainttracking1.TaintTrackingParameter::Private
 private import tainttracking1.TaintTrackingParameter::Public
 
 module Consistency {
+  private newtype TConsistencyConfiguration = MkConsistencyConfiguration()
+
+  /** A class for configuring the consistency queries. */
+  class ConsistencyConfiguration extends TConsistencyConfiguration {
+    string toString() { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `postWithInFlow`. */
+    predicate postWithInFlowExclude(Node n) { none() }
+
+    /** Holds if `n` should be excluded from the consistency test `argHasPostUpdate`. */
+    predicate argHasPostUpdateExclude(ArgumentNode n) { none() }
+  }
+
   private class RelevantNode extends Node {
     RelevantNode() {
       this instanceof ArgumentNode or
@@ -164,7 +177,7 @@ module Consistency {
 
   query predicate argHasPostUpdate(ArgumentNode n, string msg) {
     not hasPost(n) and
-    not isImmutableOrUnobservable(n) and
+    not any(ConsistencyConfiguration c).argHasPostUpdateExclude(n) and
     msg = "ArgumentNode is missing PostUpdateNode."
   }
 
@@ -177,6 +190,7 @@ module Consistency {
     isPostUpdateNode(n) and
     not clearsContent(n, _) and
     simpleLocalFlowStep(_, n) and
+    not any(ConsistencyConfiguration c).postWithInFlowExclude(n) and
     msg = "PostUpdateNode should not be the target of local flow."
   }
 }

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -1947,15 +1947,6 @@ class Unit extends TUnit {
   string toString() { result = "unit" }
 }
 
-/**
- * Holds if `n` does not require a `PostUpdateNode` as it either cannot be
- * modified or its modification cannot be observed, for example if it is a
- * freshly created object that is not saved in a variable.
- *
- * This predicate is only used for consistency checks.
- */
-predicate isImmutableOrUnobservable(Node n) { none() }
-
 class LambdaCallKind = Unit;
 
 /** Holds if `creation` is an expression that creates a delegate for `c`. */

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/FlowSummaryImpl.qll

@@ -127,6 +127,38 @@ module Public {
     SummaryComponentStack return(ReturnKind rk) { result = singleton(SummaryComponent::return(rk)) }
   }
 
+  private predicate noComponentSpecificCsv(SummaryComponent sc) {
+    not exists(getComponentSpecificCsv(sc))
+  }
+
+  /** Gets a textual representation of this component used for flow summaries. */
+  private string getComponentCsv(SummaryComponent sc) {
+    result = getComponentSpecificCsv(sc)
+    or
+    noComponentSpecificCsv(sc) and
+    (
+      exists(int i | sc = TParameterSummaryComponent(i) and result = "Parameter[" + i + "]")
+      or
+      exists(int i | sc = TArgumentSummaryComponent(i) and result = "Argument[" + i + "]")
+      or
+      sc = TReturnSummaryComponent(getReturnValueKind()) and result = "ReturnValue"
+    )
+  }
+
+  /** Gets a textual representation of this stack used for flow summaries. */
+  string getComponentStackCsv(SummaryComponentStack stack) {
+    exists(SummaryComponent head, SummaryComponentStack tail |
+      head = stack.head() and
+      tail = stack.tail() and
+      result = getComponentCsv(head) + " of " + getComponentStackCsv(tail)
+    )
+    or
+    exists(SummaryComponent c |
+      stack = TSingletonSummaryComponentStack(c) and
+      result = getComponentCsv(c)
+    )
+  }
+
   /**
    * A class that exists for QL technical reasons only (the IPA type used
    * to represent component stacks needs to be bounded).
@@ -970,18 +1002,38 @@ module Private {
   module TestOutput {
     /** A flow summary to include in the `summary/3` query predicate. */
     abstract class RelevantSummarizedCallable extends SummarizedCallable {
-      /** Gets the string representation of this callable used by `summary/3`. */
-      string getFullString() { result = this.toString() }
+      /** Gets the string representation of this callable used by `summary/1`. */
+      abstract string getCallableCsv();
+
+      /** Holds if flow is propagated between `input` and `output`. */
+      predicate relevantSummary(
+        SummaryComponentStack input, SummaryComponentStack output, boolean preservesValue
+      ) {
+        this.propagatesFlow(input, output, preservesValue)
+      }
     }
 
-    /** A query predicate for outputting flow summaries in QL tests. */
-    query predicate summary(string callable, string flow, boolean preservesValue) {
+    /** Render the kind in the format used in flow summaries. */
+    private string renderKind(boolean preservesValue) {
+      preservesValue = true and result = "value"
+      or
+      preservesValue = false and result = "taint"
+    }
+
+    /**
+     * A query predicate for outputting flow summaries in semi-colon separated format in QL tests.
+     * The syntax is: "namespace;type;overrides;name;signature;ext;inputspec;outputspec;kind",
+     * ext is hardcoded to empty.
+     */
+    query predicate summary(string csv) {
       exists(
-        RelevantSummarizedCallable c, SummaryComponentStack input, SummaryComponentStack output
+        RelevantSummarizedCallable c, SummaryComponentStack input, SummaryComponentStack output,
+        boolean preservesValue
       |
-        callable = c.getFullString() and
-        c.propagatesFlow(input, output, preservesValue) and
-        flow = input + " -> " + output
+        c.relevantSummary(input, output, preservesValue) and
+        csv =
+          c.getCallableCsv() + ";;" + getComponentStackCsv(input) + ";" +
+            getComponentStackCsv(output) + ";" + renderKind(preservesValue)
       )
     }
   }

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/FlowSummaryImplSpecific.qll

@@ -138,6 +138,26 @@ SummaryComponent interpretComponentSpecific(string c) {
   )
 }
 
+/** Gets the textual representation of the content in the format used for flow summaries. */
+private string getContentSpecificCsv(Content c) {
+  c = TElementContent() and result = "Element"
+  or
+  exists(Field f | c = TFieldContent(f) and result = "Field[" + f.getQualifiedName() + "]")
+  or
+  exists(Property p | c = TPropertyContent(p) and result = "Property[" + p.getQualifiedName() + "]")
+}
+
+/** Gets the textual representation of a summary component in the format used for flow summaries. */
+string getComponentSpecificCsv(SummaryComponent sc) {
+  exists(Content c | sc = TContentSummaryComponent(c) and result = getContentSpecificCsv(c))
+  or
+  exists(ReturnKind rk |
+    sc = TReturnSummaryComponent(rk) and
+    result = "ReturnValue[" + rk + "]" and
+    not rk instanceof NormalReturnKind
+  )
+}
+
 class SourceOrSinkElement = Element;
 
 /** Gets the return kind corresponding to specification `"ReturnValue"`. */

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImpl.qll

@@ -171,7 +171,8 @@ private module SourceVariableImpl {
       def.getTarget() = lv and
       lv.isRef() and
       lv = v.getAssignable() and
-      bb.getNode(i) = def.getAControlFlowNode()
+      bb.getNode(i) = def.getAControlFlowNode() and
+      not def.getAssignment() instanceof LocalVariableDeclAndInitExpr
     )
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImplCommon.qll

@@ -634,3 +634,29 @@ class UncertainWriteDefinition extends WriteDefinition {
     )
   }
 }
+
+/** Provides a set of consistency queries. */
+module Consistency {
+  abstract class RelevantDefinition extends Definition {
+    abstract predicate hasLocationInfo(
+      string filepath, int startline, int startcolumn, int endline, int endcolumn
+    );
+  }
+
+  query predicate nonUniqueDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    ssaDefReachesRead(v, def, bb, i) and
+    not exists(unique(Definition def0 | ssaDefReachesRead(v, def0, bb, i)))
+  }
+
+  query predicate readWithoutDef(SourceVariable v, BasicBlock bb, int i) {
+    variableRead(bb, i, v, _) and
+    not ssaDefReachesRead(v, _, bb, i)
+  }
+
+  query predicate deadDef(RelevantDefinition def, SourceVariable v) {
+    v = def.getSourceVariable() and
+    not ssaDefReachesRead(_, def, _, _) and
+    not phiHasInputFromBlock(_, def, _) and
+    not uncertainWriteDefinitionInput(_, def)
+  }
+}

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImplSpecific.qll

@@ -3,6 +3,7 @@
 private import csharp
 private import AssignableDefinitions
 private import SsaImpl as SsaImpl
+private import semmle.code.csharp.dataflow.SSA
 
 class BasicBlock = ControlFlow::BasicBlock;
 
@@ -12,7 +13,7 @@ BasicBlock getABasicBlockSuccessor(BasicBlock bb) { result = bb.getASuccessor()
 
 class ExitBasicBlock = ControlFlow::BasicBlocks::ExitBlock;
 
-class SourceVariable = SsaImpl::TSourceVariable;
+class SourceVariable = Ssa::SourceVariable;
 
 predicate variableWrite = SsaImpl::variableWrite/4;
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/dataflow/internal/basessa/SsaImplCommon.qll

@@ -634,3 +634,29 @@ class UncertainWriteDefinition extends WriteDefinition {
     )
   }
 }
+
+/** Provides a set of consistency queries. */
+module Consistency {
+  abstract class RelevantDefinition extends Definition {
+    abstract predicate hasLocationInfo(
+      string filepath, int startline, int startcolumn, int endline, int endcolumn
+    );
+  }
+
+  query predicate nonUniqueDef(RelevantDefinition def, SourceVariable v, BasicBlock bb, int i) {
+    ssaDefReachesRead(v, def, bb, i) and
+    not exists(unique(Definition def0 | ssaDefReachesRead(v, def0, bb, i)))
+  }
+
+  query predicate readWithoutDef(SourceVariable v, BasicBlock bb, int i) {
+    variableRead(bb, i, v, _) and
+    not ssaDefReachesRead(v, _, bb, i)
+  }
+
+  query predicate deadDef(RelevantDefinition def, SourceVariable v) {
+    v = def.getSourceVariable() and
+    not ssaDefReachesRead(_, def, _, _) and
+    not phiHasInputFromBlock(_, def, _) and
+    not uncertainWriteDefinitionInput(_, def)
+  }
+}

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/frameworks/JsonNET.qll

@@ -153,14 +153,14 @@ module JsonNET {
       // Serialize
       c = this.getSerializeMethod() and
       preservesValue = false and
-      source = any(CallableFlowSourceArg arg | arg.getArgumentIndex() = 0) and
-      sink = any(CallableFlowSinkArg arg | arg.getArgumentIndex() = 1)
+      source = any(CallableFlowSourceArg arg | arg.getArgumentIndex() = 1) and
+      sink = any(CallableFlowSinkArg arg | arg.getArgumentIndex() = 0)
       or
       // Deserialize
       c = this.getDeserializeMethod() and
       preservesValue = false and
       source = any(CallableFlowSourceArg arg | arg.getArgumentIndex() = 0) and
-      sink = any(CallableFlowSinkArg arg | arg.getArgumentIndex() = 1)
+      sink instanceof CallableFlowSinkReturn
     }
   }
 

repo-tests/codeql/csharp/ql/lib/semmle/code/csharp/frameworks/System.qll

@@ -92,6 +92,20 @@ class SystemBooleanStruct extends BoolType {
   }
 }
 
+/** Data flow for `System.Boolean`. */
+private class SystemBooleanFlowModelCsv extends SummaryModelCsv {
+  override predicate row(string row) {
+    row =
+      [
+        "System;Boolean;false;Parse;(System.String);;Argument[0];ReturnValue;taint",
+        "System;Boolean;false;TryParse;(System.String,System.Boolean);;Argument[0];Argument[1];taint",
+        "System;Boolean;false;TryParse;(System.String,System.Boolean);;Argument[0];ReturnValue;taint",
+        "System;Boolean;false;TryParse;(System.ReadOnlySpan<System.Char>,System.Boolean);;Element of Argument[0];Argument[1];taint",
+        "System;Boolean;false;TryParse;(System.ReadOnlySpan<System.Char>,System.Boolean);;Element of Argument[0];ReturnValue;taint",
+      ]
+  }
+}
+
 /** The `System.Convert` class. */
 class SystemConvertClass extends SystemClass {
   SystemConvertClass() { this.hasName("Convert") }
@@ -539,6 +553,22 @@ class SystemUriClass extends SystemClass {
   }
 }
 
+/** Data flow for `System.Uri`. */
+private class SystemUriFlowModelCsv extends SummaryModelCsv {
+  override predicate row(string row) {
+    row =
+      [
+        "System;Uri;false;ToString;();;Argument[-1];ReturnValue;taint",
+        "System;Uri;false;Uri;(System.String);;Argument[0];ReturnValue;taint",
+        "System;Uri;false;Uri;(System.String,System.Boolean);;Argument[0];ReturnValue;taint",
+        "System;Uri;false;Uri;(System.String,System.UriKind);;Argument[0];ReturnValue;taint",
+        "System;Uri;false;get_OriginalString;();;Argument[-1];ReturnValue;taint",
+        "System;Uri;false;get_PathAndQuery;();;Argument[-1];ReturnValue;taint",
+        "System;Uri;false;get_Query;();;Argument[-1];ReturnValue;taint",
+      ]
+  }
+}
+
 /** The `System.ValueType` class. */
 class SystemValueTypeClass extends SystemClass {
   SystemValueTypeClass() { this.hasName("ValueType") }

repo-tests/codeql/csharp/ql/lib/semmle/code/dotnet/Element.qll

@@ -14,6 +14,7 @@ class Element extends @dotnet_element {
   string toString() { none() }
 
   /** Gets the location of this element. */
+  pragma[nomagic]
   Location getLocation() { none() }
 
   /**

repo-tests/codeql/csharp/ql/src/API Abuse/UncheckedReturnValue.ql

@@ -103,11 +103,11 @@ class DiscardedMethodCall extends MethodCall {
 
   string query() {
     exists(Method m |
-      m = getTarget() and
+      m = this.getTarget() and
       not whitelist(m) and
       // Do not alert on "void wrapper methods", i.e., methods that are inserted
       // to deliberately ignore the returned value
-      not getEnclosingCallable().getStatementBody().getNumberOfStmts() = 1
+      not this.getEnclosingCallable().getStatementBody().getNumberOfStmts() = 1
     |
       important(m) and result = "should always be checked"
       or

repo-tests/codeql/csharp/ql/src/Concurrency/Concurrency.qll

@@ -4,35 +4,35 @@ import csharp
 
 private class WaitCall extends MethodCall {
   WaitCall() {
-    getTarget().hasName("Wait") and
-    getTarget().getDeclaringType().hasQualifiedName("System.Threading.Monitor")
+    this.getTarget().hasName("Wait") and
+    this.getTarget().getDeclaringType().hasQualifiedName("System.Threading.Monitor")
   }
 
-  Expr getExpr() { result = getArgument(0) }
+  Expr getExpr() { result = this.getArgument(0) }
 }
 
 /** An expression statement containing a `Wait` call. */
 class WaitStmt extends ExprStmt {
-  WaitStmt() { getExpr() instanceof WaitCall }
+  WaitStmt() { this.getExpr() instanceof WaitCall }
 
   /** Gets the expression that this wait call is waiting on. */
-  Expr getLock() { result = getExpr().(WaitCall).getExpr() }
+  Expr getLock() { result = this.getExpr().(WaitCall).getExpr() }
 
   /** Gets the variable that this wait call is waiting on, if any. */
-  Variable getWaitVariable() { result.getAnAccess() = getLock() }
+  Variable getWaitVariable() { result.getAnAccess() = this.getLock() }
 
   /** Holds if this wait call waits on `this`. */
-  predicate isWaitThis() { getLock() instanceof ThisAccess }
+  predicate isWaitThis() { this.getLock() instanceof ThisAccess }
 
   /** Gets the type that this wait call waits on, if any. */
-  Type getWaitTypeObject() { result = getLock().(TypeofExpr).getTypeAccess().getTarget() }
+  Type getWaitTypeObject() { result = this.getLock().(TypeofExpr).getTypeAccess().getTarget() }
 }
 
 private class SynchronizedMethodAttribute extends Attribute {
   SynchronizedMethodAttribute() {
-    getType().hasQualifiedName("System.Runtime.CompilerServices.MethodImplAttribute") and
+    this.getType().hasQualifiedName("System.Runtime.CompilerServices.MethodImplAttribute") and
     exists(MemberConstantAccess a, MemberConstant mc |
-      a = getArgument(0) and
+      a = this.getArgument(0) and
       a.getTarget() = mc and
       mc.hasName("Synchronized") and
       mc.getDeclaringType().hasQualifiedName("System.Runtime.CompilerServices.MethodImplOptions")
@@ -42,13 +42,13 @@ private class SynchronizedMethodAttribute extends Attribute {
 
 /** A method with attribute `[MethodImpl(MethodImplOptions.Synchronized)]`. */
 private class SynchronizedMethod extends Method {
-  SynchronizedMethod() { getAnAttribute() instanceof SynchronizedMethodAttribute }
+  SynchronizedMethod() { this.getAnAttribute() instanceof SynchronizedMethodAttribute }
 
   /** Holds if this method locks `this`. */
-  predicate isLockThis() { not isStatic() }
+  predicate isLockThis() { not this.isStatic() }
 
   /** Gets the type that is locked by this method, if any. */
-  Type getLockTypeObject() { isStatic() and result = getDeclaringType() }
+  Type getLockTypeObject() { this.isStatic() and result = this.getDeclaringType() }
 }
 
 /** A block that is locked by a `lock` statement. */
@@ -68,7 +68,7 @@ abstract class LockedBlock extends BlockStmt {
     // delegates and lambdas
     result.getParent() = this
     or
-    exists(Stmt mid | mid = getALockedStmt() and result.getParent() = mid)
+    exists(Stmt mid | mid = this.getALockedStmt() and result.getParent() = mid)
   }
 }
 

repo-tests/codeql/csharp/ql/src/Documentation/Documentation.qll

@@ -59,66 +59,66 @@ predicate isDocumentationNeeded(Modifiable decl) {
 
 /** An XML comment containing a `<returns>` tag. */
 class ReturnsXmlComment extends XmlComment {
-  ReturnsXmlComment() { getOpenTag(_) = "returns" }
+  ReturnsXmlComment() { this.getOpenTag(_) = "returns" }
 
   /** Holds if the element in this comment has a body at offset `offset`. */
-  predicate hasBody(int offset) { hasBody("returns", offset) }
+  predicate hasBody(int offset) { this.hasBody("returns", offset) }
 
   /** Holds if the element in this comment is an opening tag at offset `offset`. */
-  predicate isOpenTag(int offset) { "returns" = getOpenTag(offset) }
+  predicate isOpenTag(int offset) { "returns" = this.getOpenTag(offset) }
 
   /** Holds if the element in this comment is an empty tag at offset `offset`. */
-  predicate isEmptyTag(int offset) { "returns" = getEmptyTag(offset) }
+  predicate isEmptyTag(int offset) { "returns" = this.getEmptyTag(offset) }
 }
 
 /** An XML comment containing an `<exception>` tag. */
 class ExceptionXmlComment extends XmlComment {
-  ExceptionXmlComment() { getOpenTag(_) = "exception" }
+  ExceptionXmlComment() { this.getOpenTag(_) = "exception" }
 
   /** Gets a `cref` attribute at offset `offset`, if any. */
-  string getCref(int offset) { result = getAttribute("exception", "cref", offset) }
+  string getCref(int offset) { result = this.getAttribute("exception", "cref", offset) }
 
   /** Holds if the element in this comment has a body at offset `offset`. */
-  predicate hasBody(int offset) { hasBody("exception", offset) }
+  predicate hasBody(int offset) { this.hasBody("exception", offset) }
 }
 
 /** An XML comment containing a `<param>` tag. */
 class ParamXmlComment extends XmlComment {
-  ParamXmlComment() { getOpenTag(_) = "param" }
+  ParamXmlComment() { this.getOpenTag(_) = "param" }
 
   /** Gets the name of this parameter at offset `offset`. */
-  string getName(int offset) { getAttribute("param", "name", offset) = result }
+  string getName(int offset) { this.getAttribute("param", "name", offset) = result }
 
   /** Holds if the element in this comment has a body at offset `offset`. */
-  predicate hasBody(int offset) { hasBody("param", offset) }
+  predicate hasBody(int offset) { this.hasBody("param", offset) }
 }
 
 /** An XML comment containing a `<typeparam>` tag. */
 class TypeparamXmlComment extends XmlComment {
-  TypeparamXmlComment() { getOpenTag(_) = "typeparam" }
+  TypeparamXmlComment() { this.getOpenTag(_) = "typeparam" }
 
   /** Gets the `name` attribute of this element at offset `offset`. */
-  string getName(int offset) { getAttribute("typeparam", "name", offset) = result }
+  string getName(int offset) { this.getAttribute("typeparam", "name", offset) = result }
 
   /** Holds if the element in this comment has a body at offset `offset`. */
-  predicate hasBody(int offset) { hasBody("typeparam", offset) }
+  predicate hasBody(int offset) { this.hasBody("typeparam", offset) }
 }
 
 /** An XML comment containing a `<summary>` tag. */
 class SummaryXmlComment extends XmlComment {
-  SummaryXmlComment() { getOpenTag(_) = "summary" }
+  SummaryXmlComment() { this.getOpenTag(_) = "summary" }
 
   /** Holds if the element in this comment has a body at offset `offset`. */
-  predicate hasBody(int offset) { hasBody("summary", offset) }
+  predicate hasBody(int offset) { this.hasBody("summary", offset) }
 
   /** Holds if the element in this comment has an open tag at offset `offset`. */
-  predicate isOpenTag(int offset) { "summary" = getOpenTag(offset) }
+  predicate isOpenTag(int offset) { "summary" = this.getOpenTag(offset) }
 
   /** Holds if the element in this comment is empty at offset `offset`. */
-  predicate isEmptyTag(int offset) { "summary" = getEmptyTag(offset) }
+  predicate isEmptyTag(int offset) { "summary" = this.getEmptyTag(offset) }
 }
 
 /** An XML comment containing an `<inheritdoc>` tag. */
 class InheritDocXmlComment extends XmlComment {
-  InheritDocXmlComment() { getOpenTag(_) = "inheritdoc" }
+  InheritDocXmlComment() { this.getOpenTag(_) = "inheritdoc" }
 }

repo-tests/codeql/csharp/ql/src/Likely Bugs/NestedLoopsSameVariable.ql

@@ -62,7 +62,7 @@ class NestedForLoopSameVariable extends ForStmt {
 
   private predicate haveSameCondition() {
     exists(NestedForConditions config |
-      config.same(getInnerForStmt().getCondition(), getOuterForStmt().getCondition())
+      config.same(this.getInnerForStmt().getCondition(), this.getOuterForStmt().getCondition())
     )
   }
 
@@ -74,7 +74,7 @@ class NestedForLoopSameVariable extends ForStmt {
 
   /** Holds if the logic is deemed to be correct in limited circumstances. */
   predicate isSafe() {
-    haveSameUpdate() and haveSameCondition() and not exists(getAnUnguardedAccess())
+    this.haveSameUpdate() and this.haveSameCondition() and not exists(this.getAnUnguardedAccess())
   }
 
   /** Gets the result element. */
@@ -95,20 +95,20 @@ class NestedForLoopSameVariable extends ForStmt {
 
   /** Finds elements inside the outer loop that are no longer guarded by the loop invariant. */
   private ControlFlow::Node getAnUnguardedNode() {
-    hasChild(getOuterForStmt().getBody(), result.getElement()) and
+    hasChild(this.getOuterForStmt().getBody(), result.getElement()) and
     (
       result =
         this.getCondition().(ControlFlowElement).getAControlFlowExitNode().getAFalseSuccessor()
       or
-      exists(ControlFlow::Node mid | mid = getAnUnguardedNode() |
+      exists(ControlFlow::Node mid | mid = this.getAnUnguardedNode() |
         mid.getASuccessor() = result and
-        not exists(getAComparisonTest(result.getElement()))
+        not exists(this.getAComparisonTest(result.getElement()))
       )
     )
   }
 
   private VariableAccess getAnUnguardedAccess() {
-    result = getAnUnguardedNode().getElement() and
+    result = this.getAnUnguardedNode().getElement() and
     result.getTarget() = iteration
   }
 }

repo-tests/codeql/csharp/ql/src/Security Features/CWE-384/AbandonSession.ql

@@ -34,10 +34,10 @@ class SystemWebSessionStateHttpSessionStateClass extends Class {
   }
 
   /** Gets the `Abandon` method. */
-  Method getAbandonMethod() { result = getAMethod("Abandon") }
+  Method getAbandonMethod() { result = this.getAMethod("Abandon") }
 
   /** Gets the `Clear` method. */
-  Method getClearMethod() { result = getAMethod("Clear") }
+  Method getClearMethod() { result = this.getAMethod("Clear") }
 }
 
 /** A method that directly or indirectly clears `HttpSessionState`. */

repo-tests/codeql/csharp/ql/src/Security Features/CWE-730/ReDoS.ql

@@ -8,6 +8,7 @@
  * @precision high
  * @id cs/redos
  * @tags security
+ *       external/cwe/cwe-1333
  *       external/cwe/cwe-730
  *       external/cwe/cwe-400
  */