Merge pull request #13455 from owen-mc/dataflow/add-flowCheckNodeSpecific

Dataflow: add language-specific hook for breaking up big step relation

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

cpp/ql/lib/semmle/code/cpp/dataflow/internal/DataFlowPrivate.qll

@@ -235,6 +235,12 @@ class CastNode extends Node {
   CastNode() { none() } // stub implementation
 }
 
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) { none() }
+
 class DataFlowCallable = Function;
 
 class DataFlowExpr = Expr;

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -783,6 +783,12 @@ class CastNode extends Node {
   CastNode() { none() } // stub implementation
 }
 
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) { none() }
+
 /**
  * A function that may contain code or a variable that may contain itself. When
  * flow crosses from one _enclosing callable_ to another, the interprocedural

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DataFlowPrivate.qll

@@ -2140,6 +2140,12 @@ class CastNode extends Node {
   }
 }
 
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) { none() }
+
 class DataFlowExpr = DotNet::Expr;
 
 /** Holds if `e` is an expression that always has the same Boolean value `val`. */

go/ql/lib/semmle/go/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

go/ql/lib/semmle/go/dataflow/internal/DataFlowPrivate.qll

@@ -228,6 +228,12 @@ class CastNode extends ExprNode {
   override ConversionExpr expr;
 }
 
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) { none() }
+
 class DataFlowExpr = Expr;
 
 private newtype TDataFlowType =

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

java/ql/lib/semmle/code/java/dataflow/internal/DataFlowPrivate.qll

@@ -242,6 +242,12 @@ class CastNode extends ExprNode {
   CastNode() { this.getExpr() instanceof CastingExpr }
 }
 
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) { none() }
+
 private newtype TDataFlowCallable =
   TSrcCallable(Callable c) or
   TSummarizedCallable(SummarizedCallable c) or

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPrivate.qll

@@ -486,6 +486,14 @@ class DataFlowType extends TDataFlowType {
 
 /** A node that performs a type cast. */
 class CastNode extends Node {
+  CastNode() { none() }
+}
+
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) {
   // We include read- and store steps here to force them to be
   // shown in path explanations.
   // This hack is necessary, because we have included some of these
@@ -494,7 +502,7 @@ class CastNode extends Node {
   // We should revert this once, we can remove this steps from the
   // default taint steps; this should be possible once we have
   // implemented flow summaries and recursive content.
-  CastNode() { readStep(_, _, this) or storeStep(_, _, this) }
+  readStep(_, _, n) or storeStep(_, _, n)
 }
 
 /**

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll

@@ -1290,10 +1290,16 @@ private import PostUpdateNodes
 
 /** A node that performs a type cast. */
 class CastNode extends Node {
-  CastNode() {
-    // ensure that all variable assignments are included in the path graph
-    this.(SsaDefinitionExtNode).getDefinitionExt() instanceof Ssa::WriteDefinition
-  }
+  CastNode() { none() }
+}
+
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) {
+  // ensure that all variable assignments are included in the path graph
+  n.(SsaDefinitionExtNode).getDefinitionExt() instanceof Ssa::WriteDefinition
 }
 
 class DataFlowExpr = CfgNodes::ExprCfgNode;

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowImpl.qll

@@ -2021,7 +2021,8 @@ module Impl<FullStateConfigSig Config> {
       FlowCheckNode() {
         castNode(this.asNode()) or
         clearsContentCached(this.asNode(), _) or
-        expectsContentCached(this.asNode(), _)
+        expectsContentCached(this.asNode(), _) or
+        neverSkipInPathGraph(this.asNode())
       }
     }
 

swift/ql/lib/codeql/swift/dataflow/internal/DataFlowPrivate.qll

@@ -849,6 +849,12 @@ class CastNode extends Node {
   CastNode() { none() }
 }
 
+/**
+ * Holds if `n` should never be skipped over in the `PathGraph` and in path
+ * explanations.
+ */
+predicate neverSkipInPathGraph(Node n) { none() }
+
 class DataFlowExpr = Expr;
 
 class DataFlowParameter = ParamDecl;