C++: Don't short-circuit negations in conditions.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedCondition.qll

@@ -77,24 +77,6 @@ class TranslatedParenthesisCondition extends TranslatedFlexibleCondition {
   }
 }
 
-class TranslatedNotCondition extends TranslatedFlexibleCondition {
-  override NotExpr expr;
-
-  override Instruction getChildTrueSuccessor(TranslatedCondition child) {
-    child = this.getOperand() and
-    result = this.getConditionContext().getChildFalseSuccessor(this)
-  }
-
-  override Instruction getChildFalseSuccessor(TranslatedCondition child) {
-    child = this.getOperand() and
-    result = this.getConditionContext().getChildTrueSuccessor(this)
-  }
-
-  override TranslatedCondition getOperand() {
-    result = getTranslatedCondition(expr.getOperand().getFullyConverted())
-  }
-}
-
 abstract class TranslatedNativeCondition extends TranslatedCondition, TTranslatedNativeCondition {
   TranslatedNativeCondition() { this = TTranslatedNativeCondition(expr) }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -190,10 +190,7 @@ private predicate isNativeCondition(Expr expr) {
  * depending on context.
  */
 private predicate isFlexibleCondition(Expr expr) {
-  (
-    expr instanceof ParenthesisExpr or
-    expr instanceof NotExpr
-  ) and
+  expr instanceof ParenthesisExpr and
   usedAsCondition(expr) and
   not isIRConstant(expr)
 }
@@ -218,11 +215,6 @@ private predicate usedAsCondition(Expr expr) {
     condExpr.getCondition().getFullyConverted() = expr and not condExpr.isTwoOperand()
   )
   or
-  exists(NotExpr notExpr |
-    notExpr.getOperand().getFullyConverted() = expr and
-    usedAsCondition(notExpr)
-  )
-  or
   exists(ParenthesisExpr paren |
     paren.getExpr() = expr and
     usedAsCondition(paren)