r200380 - Short-circuit a couple of queries (and avoid corrupting

[John McCall]

Author: rjmccall
Date: Wed Jan 29 02:33:09 2014
New Revision: 200380

URL: http://llvm.org/viewvc/llvm-project?rev=200380&view=rev
Log:
Short-circuit a couple of queries (and avoid corrupting
the linkage cache) when type-checking static local
variables.

There's a very deep problem here where the linkage of
a declaration can suddenly massively change as soon as
it's given a typedef name; these fixes, while optimizations
in their own right, are really just targeted workarounds.

rdar://15928125

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

Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=200380&r1=200379&r2=200380&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Wed Jan 29 02:33:09 2014
@@ -8773,7 +8773,13 @@ void Sema::CheckCompleteVariableDeclarat
     }
   }
 
+  // Warn about externally-visible variables being defined without a
+  // prior declaration.  We only want to do this for global
+  // declarations, but we also specifically need to avoid doing it for
+  // class members because the linkage of an anonymous class can
+  // change if it's later given a typedef name.
   if (var->isThisDeclarationADefinition() &&
+      var->getDeclContext()->getRedeclContext()->isFileContext() &&
       var->isExternallyVisible() && var->hasLinkage() &&
       getDiagnostics().getDiagnosticLevel(
                        diag::warn_missing_variable_declarations,
@@ -8910,7 +8916,7 @@ Sema::FinalizeDeclaration(Decl *ThisDecl
   const DeclContext *DC = VD->getDeclContext();
   // If there's a #pragma GCC visibility in scope, and this isn't a class
   // member, set the visibility of this variable.
-  if (!DC->isRecord() && VD->isExternallyVisible())
+  if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible())
     AddPushedVisibilityAttribute(VD);
 
   if (VD->isFileVarDecl())

Modified: cfe/trunk/test/SemaCXX/linkage.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/linkage.cpp?rev=200380&r1=200379&r2=200380&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/linkage.cpp (original)
+++ cfe/trunk/test/SemaCXX/linkage.cpp Wed Jan 29 02:33:09 2014
@@ -103,3 +103,13 @@ namespace test5 {
     };
   }
 }
+
+// Test that we don't compute linkage too hastily before we're done
+// processing a record decl.  rdar://15928125
+namespace test6 {
+  typedef struct {
+    void foo() {
+      static int bar = 0; 
+    }
+  } A;
+}