Switch CodeGen's "is this variable declaration a definition?" logic
over to VarDecl::isThisDeclarationADefinition(), which handles
variables declared with linkage specifications better (among other
things). CMake 2.9 (from CVS) now builds with clang++ and is somewhat
functional.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95486 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index fc5989f..644c5d0 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -627,20 +627,7 @@
     const VarDecl *VD = cast<VarDecl>(Global);
     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
 
-    if (getLangOptions().CPlusPlus && !VD->getInit()) {
-      // In C++, if this is marked "extern", defer code generation.
-      if (VD->getStorageClass() == VarDecl::Extern || VD->isExternC())
-        return;
-
-      // If this is a declaration of an explicit specialization of a static
-      // data member in a class template, don't emit it.
-      if (VD->isStaticDataMember() && 
-          VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
-        return;
-    }
-
-    // In C, if this isn't a definition, defer code generation.
-    if (!getLangOptions().CPlusPlus && !VD->getInit())
+    if (VD->isThisDeclarationADefinition() != VarDecl::Definition)
       return;
   }