[ms-cxxabi] Fix linkage of dtor thunks for anonymous classes

We were mistakengly giving linkonce_odr linkage instead of internal
linkage to the deleting and complete destructor thunks for classes in
anonymous namespaces.

Fixes PR17273.

llvm-svn: 197060

2 files changed, 23 insertions, 6 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 41f2c6c81fe..e3ab9df9a67 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -585,11 +585,6 @@ llvm::GlobalValue::LinkageTypes
 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
   const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl());
 
-  if (isa<CXXDestructorDecl>(D) &&
-      getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
-                                         GD.getDtorType()))
-    return llvm::Function::LinkOnceODRLinkage;
-
   GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
 
   if (Linkage == GVA_Internal)
@@ -630,7 +625,14 @@ CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
     return !Context.getLangOpts().AppleKext
              ? llvm::Function::WeakODRLinkage
              : llvm::Function::ExternalLinkage;
-  
+
+  // Destructor variants in the Microsoft C++ ABI are always linkonce_odr thunks
+  // emitted on an as-needed basis.
+  if (isa<CXXDestructorDecl>(D) &&
+      getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
+                                         GD.getDtorType()))
+    return llvm::Function::LinkOnceODRLinkage;
+
   // Otherwise, we have strong external linkage.
   assert(Linkage == GVA_StrongExternal);
   return llvm::Function::ExternalLinkage;
diff --git a/clang/test/CodeGenCXX/microsoft-abi-structors.cpp b/clang/test/CodeGenCXX/microsoft-abi-structors.cpp
index c2f1395f47d..71cc31d9aec 100644
--- a/clang/test/CodeGenCXX/microsoft-abi-structors.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-structors.cpp
@@ -299,3 +299,18 @@ void call_nv_deleting_dtor(D *d) {
 }
 
 }
+
+// Dtor thunks for classes in anonymous namespaces should be internal, not
+// linkonce_odr.
+namespace {
+struct A {
+  virtual ~A() { }
+};
+}
+void *getA() {
+  return (void*)new A();
+}
+// CHECK: define internal x86_thiscallcc void @"\01??_GA@?A@@UAEPAXI@Z"
+// CHECK:               (%"struct.<anonymous namespace>::A"* %this, i32 %should_call_delete)
+// CHECK: define internal x86_thiscallcc void @"\01??1A@?A@@UAE@XZ"
+// CHECK:               (%"struct.<anonymous namespace>::A"* %this)