r185100 - Under -fms-extensions, only inject a friend tag name when we didn't see a tag with that name in an enclosing scope.

[Douglas Gregor]

Author: dgregor
Date: Thu Jun 27 15:42:30 2013
New Revision: 185100

URL: http://llvm.org/viewvc/llvm-project?rev=185100&view=rev
Log:
Under -fms-extensions, only inject a friend tag name when we didn't see a tag with that name in an enclosing scope.

r177473 made us correctly consider only those declarations in the
enclosing namespace scope when looking for a friend declaration. Under
ms-extensions mode, where we do some level of friend injection, this
meant that we were introducing a new tag type into a different scope
than what Microsoft actually does. Address this by only doing the
friend injection when we didn't see any tag with that name in any
outer scope. Fixes <rdar://problem/14250378>.

Modified:
    cfe/trunk/lib/Sema/SemaDecl.cpp
    cfe/trunk/test/SemaCXX/MicrosoftExtensions.cpp

Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=185100&r1=185099&r2=185100&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Thu Jun 27 15:42:30 2013
@@ -9614,7 +9614,7 @@ Decl *Sema::ActOnTag(Scope *S, unsigned
     Redecl = NotForRedeclaration;
 
   LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl);
-
+  bool FriendSawTagOutsideEnclosingNamespace = false;
   if (Name && SS.isNotEmpty()) {
     // We have a nested-name tag ('struct foo::bar').
 
@@ -9707,8 +9707,11 @@ Decl *Sema::ActOnTag(Scope *S, unsigned
       while (F.hasNext()) {
         NamedDecl *ND = F.next();
         DeclContext *DC = ND->getDeclContext()->getRedeclContext();
-        if (DC->isFileContext() && !EnclosingNS->Encloses(ND->getDeclContext()))
+        if (DC->isFileContext() &&
+            !EnclosingNS->Encloses(ND->getDeclContext())) {
           F.erase();
+          FriendSawTagOutsideEnclosingNamespace = true;
+        }
       }
       F.done();
     }
@@ -10208,7 +10211,8 @@ CreateNewDecl:
   // the tag name visible.
   if (TUK == TUK_Friend)
     New->setObjectOfFriendDecl(/* PreviouslyDeclared = */ !Previous.empty() ||
-                               getLangOpts().MicrosoftExt);
+                               (!FriendSawTagOutsideEnclosingNamespace &&
+                                getLangOpts().MicrosoftExt));
 
   // Set the access specifier.
   if (!Invalid && SearchDC->isRecord())

Modified: cfe/trunk/test/SemaCXX/MicrosoftExtensions.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/MicrosoftExtensions.cpp?rev=185100&r1=185099&r2=185100&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/MicrosoftExtensions.cpp (original)
+++ cfe/trunk/test/SemaCXX/MicrosoftExtensions.cpp Thu Jun 27 15:42:30 2013
@@ -365,3 +365,23 @@ void SP11::UseV() {
 struct StructWithUnnamedMember {
   __declspec(property(get=GetV)) int : 10; // expected-error {{anonymous property is not supported}}
 };
+
+namespace rdar14250378 {
+  class Bar {};
+  
+  namespace NyNamespace {
+    class Foo {
+    public:
+      Bar* EnsureBar();
+    };
+    
+    class Baz : public Foo {
+    public:
+      friend class Bar;
+    };
+    
+    Bar* Foo::EnsureBar() {
+      return 0;
+    }
+  }
+}