Merge pull request #4182 from github/igfoo/cfg

C++: Remove some remnants of the extractor CFG

cpp/ql/src/semmle/code/cpp/controlflow/ControlFlowGraph.qll

@@ -65,7 +65,7 @@ class ControlFlowNode extends Locatable, ControlFlowNodeBase {
    * taken when this expression is true.
    */
   ControlFlowNode getATrueSuccessor() {
-    truecond_base(this, result) and
+    qlCFGTrueSuccessor(this, result) and
     result = getASuccessor()
   }
 
@@ -74,7 +74,7 @@ class ControlFlowNode extends Locatable, ControlFlowNodeBase {
    * taken when this expression is false.
    */
   ControlFlowNode getAFalseSuccessor() {
-    falsecond_base(this, result) and
+    qlCFGFalseSuccessor(this, result) and
     result = getASuccessor()
   }
 
@@ -95,18 +95,20 @@ import ControlFlowGraphPublic
 class ControlFlowNodeBase extends ElementBase, @cfgnode { }
 
 /**
+ * DEPRECATED: Use `ControlFlowNode.getATrueSuccessor()` instead.
  * Holds when `n2` is a control-flow node such that the control-flow
  * edge `(n1, n2)` may be taken when `n1` is an expression that is true.
  */
-predicate truecond_base(ControlFlowNodeBase n1, ControlFlowNodeBase n2) {
+deprecated predicate truecond_base(ControlFlowNodeBase n1, ControlFlowNodeBase n2) {
   qlCFGTrueSuccessor(n1, n2)
 }
 
 /**
+ * DEPRECATED: Use `ControlFlowNode.getAFalseSuccessor()` instead.
  * Holds when `n2` is a control-flow node such that the control-flow
  * edge `(n1, n2)` may be taken when `n1` is an expression that is false.
  */
-predicate falsecond_base(ControlFlowNodeBase n1, ControlFlowNodeBase n2) {
+deprecated predicate falsecond_base(ControlFlowNodeBase n1, ControlFlowNodeBase n2) {
   qlCFGFalseSuccessor(n1, n2)
 }
 
@@ -134,7 +136,7 @@ abstract class AdditionalControlFlowEdge extends ControlFlowNodeBase {
 /**
  * Holds if there is a control-flow edge from `source` to `target` in either
  * the extractor-generated control-flow graph or in a subclass of
- * `AdditionalControlFlowEdge`. Use this relation instead of `successors`.
+ * `AdditionalControlFlowEdge`. Use this relation instead of `qlCFGSuccessor`.
  */
 predicate successors_extended(ControlFlowNodeBase source, ControlFlowNodeBase target) {
   qlCFGSuccessor(source, target)

cpp/ql/src/semmle/code/cpp/controlflow/internal/CFG.qll

@@ -1376,8 +1376,6 @@ private module Cached {
   /**
    * Holds if `n2` is a successor of `n1` in the CFG. This includes also
    * true-successors and false-successors.
-   *
-   * This corresponds to the old `successors` dbscheme relation.
    */
   cached
   predicate qlCFGSuccessor(Node n1, Node n2) {
@@ -1390,9 +1388,8 @@ private module Cached {
   }
 
   /**
-   * Holds if `n2` is a true-successor of `n1` in the CFG.
-   *
-   * This corresponds to the old `truecond` dbscheme relation.
+   * Holds if `n2` is a control-flow node such that the control-flow
+   * edge `(n1, n2)` may be taken when `n1` is an expression that is true.
    */
   cached
   predicate qlCFGTrueSuccessor(Node n1, Node n2) {
@@ -1401,9 +1398,8 @@ private module Cached {
   }
 
   /**
-   * Holds if `n2` is a false-successor of `n1` in the CFG.
-   *
-   * This corresponds to the old `falsecond` dbscheme relation.
+   * Holds if `n2` is a control-flow node such that the control-flow
+   * edge `(n1, n2)` may be taken when `n1` is an expression that is false.
    */
   cached
   predicate qlCFGFalseSuccessor(Node n1, Node n2) {

cpp/ql/src/semmle/code/cpp/controlflow/internal/ConstantExprs.qll

@@ -1,5 +1,6 @@
 import cpp
 private import PrimitiveBasicBlocks
+private import semmle.code.cpp.controlflow.internal.CFG
 
 private class Node = ControlFlowNodeBase;
 
@@ -153,8 +154,8 @@ private predicate nonAnalyzableFunction(Function f) {
  */
 private predicate impossibleFalseEdge(Expr condition, Node succ) {
   conditionAlwaysTrue(condition) and
-  falsecond_base(condition, succ) and
-  not truecond_base(condition, succ)
+  qlCFGFalseSuccessor(condition, succ) and
+  not qlCFGTrueSuccessor(condition, succ)
 }
 
 /**
@@ -162,8 +163,8 @@ private predicate impossibleFalseEdge(Expr condition, Node succ) {
  */
 private predicate impossibleTrueEdge(Expr condition, Node succ) {
   conditionAlwaysFalse(condition) and
-  truecond_base(condition, succ) and
-  not falsecond_base(condition, succ)
+  qlCFGTrueSuccessor(condition, succ) and
+  not qlCFGFalseSuccessor(condition, succ)
 }
 
 /**
@@ -863,9 +864,9 @@ library class ConditionEvaluator extends ExprEvaluator {
   ConditionEvaluator() { this = 0 }
 
   override predicate interesting(Expr e) {
-    falsecond_base(e, _)
+    qlCFGFalseSuccessor(e, _)
     or
-    truecond_base(e, _)
+    qlCFGTrueSuccessor(e, _)
   }
 }
 

cpp/ql/src/semmlecode.cpp.dbscheme

@@ -1935,20 +1935,6 @@ stmtparents(
 ishandler(unique int block: @stmt_block ref);
 
 @cfgnode = @stmt | @expr | @function | @initialiser ;
-successors(
-    int from: @cfgnode ref,
-    int to: @cfgnode ref
-);
-
-truecond(
-    unique int from: @cfgnode ref,
-    int to: @cfgnode ref
-);
-
-falsecond(
-    unique int from: @cfgnode ref,
-    int to: @cfgnode ref
-);
 
 stmt_decl_bind(
     int stmt: @stmt_decl ref,

cpp/ql/test/library-tests/syntax-zoo/Compare.qll

@@ -1,148 +0,0 @@
-import cpp
-import semmle.code.cpp.controlflow.internal.CFG
-
-class DestructorCallEnhanced extends DestructorCall {
-  override string toString() {
-    if exists(this.getQualifier().(VariableAccess).getTarget().getName())
-    then
-      result =
-        "call to " + this.getQualifier().(VariableAccess).getTarget().getName() + "." +
-          this.getTarget().getName()
-    else result = super.toString()
-  }
-}
-
-predicate differentEdge(ControlFlowNode n1, ControlFlowNode n2, string msg) {
-  successors(n1, n2) and
-  not qlCFGSuccessor(n1, n2) and
-  msg = "Standard edge, only from extractor"
-  or
-  not successors(n1, n2) and
-  qlCFGSuccessor(n1, n2) and
-  msg = "Standard edge, only from QL"
-  or
-  truecond_base(n1, n2) and
-  not qlCFGTrueSuccessor(n1, n2) and
-  msg = "True edge, only from extractor"
-  or
-  not truecond_base(n1, n2) and
-  qlCFGTrueSuccessor(n1, n2) and
-  msg = "True edge, only from QL"
-  or
-  falsecond_base(n1, n2) and
-  not qlCFGFalseSuccessor(n1, n2) and
-  msg = "False edge, only from extractor"
-  or
-  not falsecond_base(n1, n2) and
-  qlCFGFalseSuccessor(n1, n2) and
-  msg = "False edge, only from QL"
-}
-
-predicate differentScope(Element e) {
-  exists(ControlFlowNode n1 |
-    getScopeElement(n1) = e and
-    differentEdge(n1, _, _)
-  )
-}
-
-private predicate isInFunction(ControlFlowNode x, Function f) {
-  f = x.getControlFlowScope()
-  or
-  exists(ControlFlowNode y |
-    successors(unresolveElement(x), unresolveElement(y))
-    or
-    successors(unresolveElement(y), unresolveElement(x))
-  |
-    isInFunction(y, f)
-  )
-}
-
-Element getScopeElement(ControlFlowNode x) {
-  isInFunction(x, result)
-  or
-  not isInFunction(x, _) and
-  result = x.getFile()
-}
-
-string getScopeName(ControlFlowNode x) {
-  exists(Function scope | scope = getScopeElement(x) |
-    differentScope(scope) and
-    result =
-      scope.getFile().getBaseName().splitAt(".", 0) + "__" +
-        scope.getQualifiedName().replaceAll("::", "_")
-  )
-  or
-  exists(File scope | scope = getScopeElement(x) |
-    differentScope(scope) and
-    result = scope.getBaseName()
-  )
-}
-
-module QLCFG {
-  private predicate isNode(boolean isEdge, ControlFlowNode x, ControlFlowNode y, string label) {
-    isEdge = false and x = y and label = x.toString()
-  }
-
-  private predicate isSuccessor(boolean isEdge, ControlFlowNode x, ControlFlowNode y, string label) {
-    exists(string truelabel, string falselabel |
-      isEdge = true and
-      qlCFGSuccessor(x, y) and
-      (if qlCFGTrueSuccessor(x, y) then truelabel = "T" else truelabel = "") and
-      (if qlCFGFalseSuccessor(x, y) then falselabel = "F" else falselabel = "") and
-      label = truelabel + falselabel
-    )
-  }
-
-  predicate qltestGraph(
-    Element scopeElement, string scopeString, boolean isEdge, ControlFlowNode x, ControlFlowNode y,
-    string label
-  ) {
-    scopeElement = getScopeElement(x) and
-    scopeString = getScopeName(x) + "_ql" and
-    (
-      isNode(isEdge, x, y, label)
-      or
-      isSuccessor(isEdge, x, y, label)
-    )
-  }
-}
-
-module ExtractorCFG {
-  predicate isNode(boolean isEdge, ControlFlowNode x, ControlFlowNode y, string label) {
-    isEdge = false and x = y and label = x.toString()
-  }
-
-  predicate isSuccessor(boolean isEdge, ControlFlowNode x, ControlFlowNode y, string label) {
-    exists(string truelabel, string falselabel |
-      isEdge = true and
-      successors(x, y) and
-      (if truecond_base(x, y) then truelabel = "T" else truelabel = "") and
-      (if falsecond_base(x, y) then falselabel = "F" else falselabel = "") and
-      label = truelabel + falselabel
-    )
-  }
-
-  predicate qltestGraph(
-    Element scopeElement, string scopeString, boolean isEdge, ControlFlowNode x, ControlFlowNode y,
-    string label
-  ) {
-    scopeElement = getScopeElement(x) and
-    scopeString = getScopeName(x) + "_extractor" and
-    (
-      isNode(isEdge, x, y, label)
-      or
-      isSuccessor(isEdge, x, y, label)
-    )
-  }
-}
-
-module AllCFG {
-  predicate qltestGraph(
-    Element scopeElement, string scopeString, boolean isEdge, ControlFlowNode x, ControlFlowNode y,
-    string label
-  ) {
-    QLCFG::qltestGraph(scopeElement, scopeString, isEdge, x, y, label)
-    or
-    ExtractorCFG::qltestGraph(scopeElement, scopeString, isEdge, x, y, label)
-  }
-}