Do not emit duplicate global initializers for template static data members inside namespaces

A quirk of AST representation leads to class template static data member
definitions being visited twice during Clang IRGen resulting in
duplicate (benign) initializers.

Discovered while investigating a possibly-related debug info bug tickled
by the duplicate emission of these members & their associated debug
info.

With thanks to Richard Smith for help investigating, understanding, and
helping with the fix.

llvm-svn: 189996

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 3b28d9d07fb..6c126718431 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2761,8 +2761,13 @@ void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
 /// EmitNamespace - Emit all declarations in a namespace.
 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
   for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end();
-       I != E; ++I)
+       I != E; ++I) {
+    if (const VarDecl *VD = dyn_cast<VarDecl>(*I))
+      if (VD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization &&
+          VD->getTemplateSpecializationKind() != TSK_Undeclared)
+        continue;
     EmitTopLevelDecl(*I);
+  }
 }
 
 // EmitLinkageSpec - Emit all declarations in a linkage spec.