Move the check that gives functions with unique-external types unique-external

linkage into Decl.cpp.  Disable this logic for extern "C" functions, because
the operative rule there is weaker.  Fixes rdar://problem/8898466

llvm-svn: 125268

2 files changed, 13 insertions, 4 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index d6c89c947ce..6b267432586 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -5859,10 +5859,6 @@ GVALinkage ASTContext::GetGVALinkageForFunction(const FunctionDecl *FD) {
   GVALinkage External = GVA_StrongExternal;
 
   Linkage L = FD->getLinkage();
-  if (L == ExternalLinkage && getLangOptions().CPlusPlus &&
-      FD->getType()->getLinkage() == UniqueExternalLinkage)
-    L = UniqueExternalLinkage;
-  
   switch (L) {
   case NoLinkage:
   case InternalLinkage:
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 11614df5003..9aeb04fa448 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -392,6 +392,14 @@ static LinkageInfo getLVForNamespaceScopeDecl(const NamedDecl *D, LVFlags F) {
       }
     }
 
+    // In C++, then if the type of the function uses a type with
+    // unique-external linkage, it's not legally usable from outside
+    // this translation unit.  However, we should use the C linkage
+    // rules instead for extern "C" declarations.
+    if (Context.getLangOptions().CPlusPlus && !Function->isExternC() &&
+        Function->getType()->getLinkage() == UniqueExternalLinkage)
+      return LinkageInfo::uniqueExternal();
+
     if (FunctionTemplateSpecializationInfo *SpecInfo
                                = Function->getTemplateSpecializationInfo()) {
       LV.merge(getLVForDecl(SpecInfo->getTemplate(),
@@ -512,6 +520,11 @@ static LinkageInfo getLVForClassMember(const NamedDecl *D, LVFlags F) {
     return LinkageInfo::uniqueExternal();
 
   if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
+    // If the type of the function uses a type with unique-external
+    // linkage, it's not legally usable from outside this translation unit.
+    if (MD->getType()->getLinkage() == UniqueExternalLinkage)
+      return LinkageInfo::uniqueExternal();
+
     TemplateSpecializationKind TSK = TSK_Undeclared;
 
     // If this is a method template specialization, use the linkage for