Fix crash on invalid in microsoft anonymous struct extension.

Fixes PR11847. Patch from Jason Haslam!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149460 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaDecl.cpp

@@ -2952,9 +2952,10 @@ Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
   SmallVector<NamedDecl*, 2> Chain;
   Chain.push_back(Anon);
 
-  if (InjectAnonymousStructOrUnionMembers(*this, S, CurContext,
-                                          Record->getDefinition(),
-                                          AS_none, Chain, true))
+  RecordDecl *RecordDef = Record->getDefinition();
+  if (!RecordDef || InjectAnonymousStructOrUnionMembers(*this, S, CurContext,
+                                                        RecordDef, AS_none,
+                                                        Chain, true))
     Anon->setInvalidDecl();
 
   return Anon;

test/Sema/MicrosoftExtensions.c

@@ -87,3 +87,12 @@ void pointer_to_integral_type_conv(char* ptr) {
    ch = (char)ptr;
    sh = (short)ptr;
 }
+
+
+typedef struct {
+  UNKNOWN u; // expected-error {{unknown type name 'UNKNOWN'}}
+} AA;
+
+typedef struct {
+  AA; // expected-warning {{anonymous structs are a Microsoft extension}}
+} BB;