CPP: Improve nonReturningFunction.

geoffw0 · geoffw0 · commit 6e940d7bf257 · 2018-10-30T14:25:38.000Z
diff --git a/cpp/ql/src/semmle/code/cpp/controlflow/internal/ConstantExprs.qll b/cpp/ql/src/semmle/code/cpp/controlflow/internal/ConstantExprs.qll
@@ -138,20 +138,23 @@ private predicate impossibleDefaultSwitchEdge(Block switchBlock, DefaultCase dc)
 
 /**
  * Holds if the function `f` never returns due to not containing a return
- * statement (explicit or compiler generated).  Reachability of return
+ * statement (explicit or compiler generated).  This can be thought of as
+ * a lightweight `potentiallyReturningFunction`- reachability of return
  * statements is not checked.
  */
 private predicate nonReturningFunction(Function f)
 {
   exists(f.getBlock()) and
-  not exists(ReturnStmt ret | ret.getEnclosingFunction() = f)
+  not exists(ReturnStmt ret | ret.getEnclosingFunction() = f) and
+  not getOptions().exits(f)
 }
 
 /**
  * An edge from a call to a function that never returns is impossible.
  */
 private predicate impossibleFunctionReturn(FunctionCall fc, Node succ) {
   nonReturningFunction(fc.getTarget()) and
+  not fc.isVirtual() and
   successors_extended(fc, succ)
 }
 
