[PATCH] D49213: [analyzer] pr38072: Suppress an assertion failure for eliding the same destructor twice due to the default argument problem.

[Artem Dergachev via Phabricator via cfe-commits]

NoQ created this revision.
NoQ added reviewers: dcoughlin, xazax.hun, a.sidorin, george.karpenkov, szepet, rnkovacs.
Herald added subscribers: cfe-commits, mikhail.ramalho, baloghadamsoftware.

@alexfh provided an example that demonstrates that elided copy constructors may get agglutinated due to improper control flow when default arguments are involved.

Suppress the assertion failure for now. Proper support is still an open problem.


Repository:
  rC Clang

https://reviews.llvm.org/D49213

Files:
  lib/StaticAnalyzer/Core/ExprEngine.cpp
  test/Analysis/temporaries.cpp


Index: test/Analysis/temporaries.cpp
===================================================================
--- test/Analysis/temporaries.cpp
+++ test/Analysis/temporaries.cpp
@@ -458,6 +458,21 @@
 #endif // TEMPORARY_DTORS
 }
 
+namespace default_param_elided_destructors {
+struct a {
+  ~a();
+};
+struct F {
+  a d;
+  F(char *, a = a());
+};
+void g() {
+  char h[1];
+  for (int i = 0;;)
+    F j(i ? j : h);
+}
+} // namespace default_param_elided_destructors
+
 void testStaticMaterializeTemporaryExpr() {
   static const Trivial &ref = getTrivial();
   clang_analyzer_eval(ref.value == 42); // expected-warning{{TRUE}}
Index: lib/StaticAnalyzer/Core/ExprEngine.cpp
===================================================================
--- lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -458,7 +458,8 @@
                                             const CXXBindTemporaryExpr *BTE,
                                             const LocationContext *LC) {
   ConstructedObjectKey Key({BTE, /*IsElided=*/true}, LC);
-  assert(!State->contains<ObjectsUnderConstruction>(Key));
+  // FIXME: Currently the state might already contain the marker due to
+  // incorrect handling of temporaries bound to default parameters.
   return State->set<ObjectsUnderConstruction>(Key, UnknownVal());
 }
 


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