[Sema] Fix crash-on-invalid-code issue:

@class I;
@implementation I(cat) // crashes here
@end

rdar://10968158

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151931 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 5 insertions, 1 deletions

diff --git a/lib/AST/DeclObjC.cpp b/lib/AST/DeclObjC.cpp
index 996e93a8f9..7822eb217f 100644
--- a/lib/AST/DeclObjC.cpp
+++ b/lib/AST/DeclObjC.cpp
@@ -806,6 +806,10 @@ ObjCIvarDecl *ObjCInterfaceDecl::all_declared_ivar_begin() {
 ///
 ObjCCategoryDecl *
 ObjCInterfaceDecl::FindCategoryDeclaration(IdentifierInfo *CategoryId) const {
+  // FIXME: Should make sure no callers ever do this.
+  if (!hasDefinition())
+    return 0;
+
   if (data().ExternallyCompleted)
     LoadExternalDefinition();
 
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 9b492600ca..4df5ab3916 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -820,7 +820,7 @@ Decl *Sema::ActOnStartCategoryImplementation(
                       IdentifierInfo *CatName, SourceLocation CatLoc) {
   ObjCInterfaceDecl *IDecl = getObjCInterfaceDecl(ClassName, ClassLoc, true);
   ObjCCategoryDecl *CatIDecl = 0;
-  if (IDecl) {
+  if (IDecl && IDecl->hasDefinition()) {
     CatIDecl = IDecl->FindCategoryDeclaration(CatName);
     if (!CatIDecl) {
       // Category @implementation with no corresponding @interface.