Work around missing handling of temporaries bound to default arguments.

Yet more problems due to the missing CXXBindTemporaryExpr in the CFG for
default arguments.

Unfortunately we cannot just switch off inserting temporaries for the
corresponding default arguments, as that breaks existing tests
(test/SemaCXX/return-noreturn.cpp:245).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215554 91177308-0d34-0410-b5e6-96231b3b80d8

lib/StaticAnalyzer/Core/ExprEngine.cpp

@@ -681,8 +681,11 @@ void ExprEngine::ProcessTemporaryDtor(const CFGTemporaryDtor D,
   StmtBldr.generateNode(D.getBindTemporaryExpr(), Pred, State);
 
   QualType varType = D.getBindTemporaryExpr()->getSubExpr()->getType();
-  assert(CleanDtorState.size() == 1);
-  ExplodedNode *CleanPred = *CleanDtorState.begin();
+  // FIXME: Currently CleanDtorState can be empty here due to temporaries being
+  // bound to default parameters.
+  assert(CleanDtorState.size() <= 1);
+  ExplodedNode *CleanPred =
+      CleanDtorState.empty() ? Pred : *CleanDtorState.begin();
   // FIXME: Inlining of temporary destructors is not supported yet anyway, so
   // we just put a NULL region for now. This will need to be changed later.
   VisitCXXDestructor(varType, nullptr, D.getBindTemporaryExpr(),
@@ -718,10 +721,16 @@ void ExprEngine::VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
   StmtNodeBuilder StmtBldr(PreVisit, Dst, *currBldrCtx);
   for (ExplodedNode *Node : PreVisit) {
     ProgramStateRef State = Node->getState();
-    assert(!State->contains<InitializedTemporariesSet>(
-        std::make_pair(BTE, Node->getStackFrame())));
-    State = State->add<InitializedTemporariesSet>(
-        std::make_pair(BTE, Node->getStackFrame()));
+
+    if (!State->contains<InitializedTemporariesSet>(
+            std::make_pair(BTE, Node->getStackFrame()))) {
+      // FIXME: Currently the state might already contain the marker due to
+      // incorrect handling of temporaries bound to default parameters; for
+      // those, we currently skip the CXXBindTemporaryExpr but rely on adding
+      // temporary destructor nodes.
+      State = State->add<InitializedTemporariesSet>(
+          std::make_pair(BTE, Node->getStackFrame()));
+    }
     StmtBldr.generateNode(BTE, Node, State);
   }
 }

test/Analysis/temporaries.cpp

@@ -398,6 +398,27 @@ namespace destructors {
   void testDefaultParameters() {
     f();
   }
+
+  struct DefaultParam {
+    DefaultParam(int, const Dtor& d = Dtor());
+    ~DefaultParam();
+  };
+  void testDefaultParamConstructorsInLoops() {
+    while (true) {
+      // FIXME: This exact pattern triggers the temporary cleanup logic
+      // to fail when adding a 'clean' state.
+      DefaultParam(42);
+      DefaultParam(42);
+    }
+  }
+  void testDefaultParamConstructorsInTernariesInLoops(bool value) {
+    while (true) {
+      // FIXME: This exact pattern triggers the temporary cleanup logic
+      // to visit the bind-temporary logic with a state that already has that
+      // temporary marked as executed.
+      value ? DefaultParam(42) : DefaultParam(42);
+    }
+  }
 #endif // TEMPORARY_DTORS
 }