When forming a cycle in objc's inheritance hierarchy,

diagnose it properly and don't throw clang into an
infinit loop. // rdar://9653341

llvm-svn: 133773

1 files changed, 5 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index b54e2425b2c..3bbe421cd14 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -491,10 +491,13 @@ ActOnStartClassInterface(SourceLocation AtInterfaceLoc,
         if (!SuperClassDecl)
           Diag(SuperLoc, diag::err_undef_superclass)
             << SuperName << ClassName << SourceRange(AtInterfaceLoc, ClassLoc);
-        else if (SuperClassDecl->isForwardDecl())
-          Diag(SuperLoc, diag::err_undef_superclass)
+        else if (SuperClassDecl->isForwardDecl()) {
+          Diag(SuperLoc, diag::err_forward_superclass)
             << SuperClassDecl->getDeclName() << ClassName
             << SourceRange(AtInterfaceLoc, ClassLoc);
+          Diag(SuperClassDecl->getLocation(), diag::note_forward_class);
+          SuperClassDecl = 0;
+        }
       }
       IDecl->setSuperClass(SuperClassDecl);
       IDecl->setSuperClassLoc(SuperLoc);