From: Manuel Klimek <klimek@google.com>
Date: Wed, 13 Aug 2014 15:25:55 +0000 (+0000)
Subject: Work around missing handling of temporaries bound to default arguments.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e216a3b10b0f98c204ab2a94e11e2f144922a258;p=clang

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
---

diff --git a/lib/StaticAnalyzer/Core/ExprEngine.cpp b/lib/StaticAnalyzer/Core/ExprEngine.cpp
index e837f5b740..4743bd6e60 100644
--- a/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/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);
   }
 }
diff --git a/test/Analysis/temporaries.cpp b/test/Analysis/temporaries.cpp
index b1099d1f20..6e476339cb 100644
--- a/test/Analysis/temporaries.cpp
+++ b/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
 }