[cfe-commits] r137426 - in /cfe/trunk: lib/Analysis/CFG.cpptest/SemaCXX/cfg.cpp

[Xu Zhongxing]

Hi Ted,


This code is ill-formed per n3242: 6.7 p3. gcc rejects it. But clang accepts it. Do we need to handle it?
 
 
------------------ Original ------------------
From:  "kremenek"<kremenek at apple.com>;
Date:  Fri, Aug 12, 2011 12:09 PM
To:  "cfe-commits"<cfe-commits at cs.uiuc.edu>; 

Subject:  [cfe-commits] r137426 - in /cfe/trunk: lib/Analysis/CFG.cpptest/SemaCXX/cfg.cpp

 
 Author: kremenek
Date: Thu Aug 11 23:09:00 2011
New Revision: 137426

URL: http://llvm.org/viewvc/llvm-project?rev=137426&view=rev
Log:
Fix crash in CFGBuilder involving implicit destructor calls and gotos jumping after an object was declared.  Fixes PR 10620.

Added:
    cfe/trunk/test/SemaCXX/cfg.cpp
Modified:
    cfe/trunk/lib/Analysis/CFG.cpp

Modified: cfe/trunk/lib/Analysis/CFG.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CFG.cpp?rev=137426&r1=137425&r2=137426&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/CFG.cpp (original)
+++ cfe/trunk/lib/Analysis/CFG.cpp Thu Aug 11 23:09:00 2011
@@ -191,8 +191,8 @@
   int D = 0;
   const_iterator F = *this;
   while (F.Scope != L.Scope) {
-    assert (F != const_iterator()
-        && "L iterator is not reachable from F iterator.");
+    if (F == const_iterator())
+      return D;
     D += F.VarIter;
     F = F.Scope->Prev;
   }
@@ -816,10 +816,12 @@
 /// performed in place specified with iterator.
 void CFGBuilder::insertAutomaticObjDtors(CFGBlock* Blk, CFGBlock::iterator I,
     LocalScope::const_iterator B, LocalScope::const_iterator E, Stmt* S) {
-  BumpVectorContext& C = cfg->getBumpVectorContext();
-  I = Blk->beginAutomaticObjDtorsInsert(I, B.distance(E), C);
-  while (B != E)
-    I = Blk->insertAutomaticObjDtor(I, *B++, S);
+  if (int Cnt = B.distance(E)) {
+    BumpVectorContext& C = cfg->getBumpVectorContext();
+    I = Blk->beginAutomaticObjDtorsInsert(I, Cnt, C);
+    while (B != E)
+      I = Blk->insertAutomaticObjDtor(I, *B++, S);
+  }
 }
 
 /// appendAutomaticObjDtors - Append destructor CFGElements for variables with

Added: cfe/trunk/test/SemaCXX/cfg.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cfg.cpp?rev=137426&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/cfg.cpp (added)
+++ cfe/trunk/test/SemaCXX/cfg.cpp Thu Aug 11 23:09:00 2011
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -fsyntax-only -Wuninitialized -fsyntax-only %s
+
+// Test that the CFG builder handles destructors and gotos jumping between
+// scope boundaries.  Previously this crashed (PR 10620).
+struct S_10620 {
+  S_10620(const S_10620 &x);
+  ~S_10620();
+};
+void PR10620(int x, const S_10620& s) {
+  if (x) {
+    goto done;
+  }
+  const S_10620 s2(s);
+done:
+  ;
+}
+void PR10620_2(int x, const S_10620& s) {
+  if (x)
+    goto done;
+  const S_10620 s2(s);
+done:
+  ;
+}
\ No newline at end of file


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