When defining a forward-declared enum, don't try to attach the definition to

a previous declaration if the redeclaration is invalid. That way lies madness.
Fixes a crash-on-invalid reported by Abramo.

llvm-svn: 153349

2 files changed, 5 insertions, 3 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 71f567f47ab..68b27ef1f98 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8260,10 +8260,11 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
             EnumUnderlyingTy = QualType(T, 0);
 
           // All conflicts with previous declarations are recovered by
-          // returning the previous declaration.
+          // returning the previous declaration, unless this is a definition,
+          // in which case we want the caller to bail out.
           if (CheckEnumRedeclaration(NameLoc.isValid() ? NameLoc : KWLoc,
                                      ScopedEnum, EnumUnderlyingTy, PrevEnum))
-            return PrevTagDecl;
+            return TUK == TUK_Declaration ? PrevTagDecl : 0;
         }
 
         if (!Invalid) {
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index afa65ea9ee4..307cccce8bc 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1848,7 +1848,8 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
         // specialization causes the implicit instantiation of the definitions
         // of unscoped member enumerations.
         // Record a point of instantiation for this implicit instantiation.
-        if (TSK == TSK_ImplicitInstantiation && !Enum->isScoped()) {
+        if (TSK == TSK_ImplicitInstantiation && !Enum->isScoped() &&
+            Enum->isCompleteDefinition()) {
           MemberSpecializationInfo *MSInfo =Enum->getMemberSpecializationInfo();
           assert(MSInfo && "no spec info for member enum specialization");
           MSInfo->setTemplateSpecializationKind(TSK_ImplicitInstantiation);