r178975 - Sema: Don't crash when trying to emit a warning for a duplicate value in an invalid enum.

[Benjamin Kramer]

Author: d0k
Date: Sun Apr  7 09:10:40 2013
New Revision: 178975

URL: http://llvm.org/viewvc/llvm-project?rev=178975&view=rev
Log:
Sema: Don't crash when trying to emit a warning for a duplicate value in an invalid enum.

Fixes PR15693. A null check on a pointer returned from cast<> is a very dubious
construct, do we have a checker for this somewhere?

Modified:
    cfe/trunk/lib/Sema/SemaDecl.cpp
    cfe/trunk/test/Sema/warn-duplicate-enum.c

Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=178975&r1=178974&r2=178975&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Sun Apr  7 09:10:40 2013
@@ -11538,7 +11538,7 @@ static void CheckForDuplicateEnumValues(
   // Populate the EnumMap with all values represented by enum constants without
   // an initialier.
   for (unsigned i = 0; i < NumElements; ++i) {
-    EnumConstantDecl *ECD = cast<EnumConstantDecl>(Elements[i]);
+    EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Elements[i]);
 
     // Null EnumConstantDecl means a previous diagnostic has been emitted for
     // this constant.  Skip this enum since it may be ill-formed.

Modified: cfe/trunk/test/Sema/warn-duplicate-enum.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-duplicate-enum.c?rev=178975&r1=178974&r2=178975&view=diff
==============================================================================
--- cfe/trunk/test/Sema/warn-duplicate-enum.c (original)
+++ cfe/trunk/test/Sema/warn-duplicate-enum.c Sun Apr  7 09:10:40 2013
@@ -90,3 +90,12 @@ enum {
   NMax = N2,
   NCount = NMax + 1
 };
+
+// PR15693
+enum enum1 {
+  VALUE // expected-note{{previous definition is here}}
+};
+
+enum enum2 {
+  VALUE // expected-error{{redefinition of enumerator 'VALUE'}}
+};