set dso_local on tls init functions

[• espindola]

Summary

We copy the visibility, so copying the dso_local flag seems the natural thing to do.

[• espindola]

Richard, you added the setVisibility line, are you OK with the change?

[rnk]

I think Richard has been really busy preparing for some C++ committee function. I think we should go forward with this.

[• espindola]

r326961

lib/CodeGen/ItaniumCXXABI.cpp

if (VD->hasDefinition()) {
       llvm::FunctionType *FnTy = llvm::FunctionType::get(CGM.VoidTy, false);
       Init = llvm::Function::Create(FnTy,
                                     llvm::GlobalVariable::ExternalWeakLinkage,
                                     InitFnName.str(), &CGM.getModule());
       const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
       CGM.SetLLVMFunctionAttributes(nullptr, FI, cast<llvm::Function>(Init));
     }
 
-    if (Init)
+    if (Init) {
       Init->setVisibility(Var->getVisibility());
+      Init->setDSOLocal(Var->isDSOLocal());
+    }
 
     llvm::LLVMContext &Context = CGM.getModule().getContext();
     llvm::BasicBlock *Entry = llvm::BasicBlock::Create(Context, "", Wrapper);
     CGBuilderTy Builder(CGM, Entry);
     if (InitIsInitFunc) {
       if (Init) {
         llvm::CallInst *CallVal = Builder.CreateCall(Init);
         if (isThreadWrapperReplaceable(VD, CGM))

test/CodeGenCXX/runtime-dllstorage.cpp

 // CHECK-MS-DAG: declare i32 @__tlregdtor(void ()*)
 // CHECK-MS-DAG: declare i32 @atexit(void ()*)
 // CHECK-MS-DYNAMIC-DAG: declare dllimport {{.*}} void @_CxxThrowException
 // CHECK-MS-STATIC-DAG: declare {{.*}} void @_CxxThrowException
 // CHECK-MS-DAG: declare dso_local noalias i8* @"\01??2@YAPAXI@Z"
 // CHECK-MS-DAG: declare void @_Init_thread_header(i32*)
 // CHECK-MS-DAG: declare void @_Init_thread_footer(i32*)
 
+// CHECK-IA-DAG: @_ZTH1t = dso_local alias void (), void ()* @__tls_init
 // CHECK-IA-DAG: declare i32 @__gxx_personality_v0(...)
 // CHECK-IA-DAG: define linkonce_odr hidden void @__clang_call_terminate(i8*)
 
 // CHECK-DYNAMIC-IA-DAG: declare dllimport i32 @__cxa_thread_atexit(void (i8*)*, i8*, i8*)
 // CHECK-DYNAMIC-IA-DAG: declare dllimport i32 @__cxa_atexit(void (i8*)*, i8*, i8*)
 // CHECK-DYNAMIC-IA-DECL-DAG: declare i8* @__cxa_allocate_exception(i32)
 // CHECK-DYNAMIC-IA-NODECL-DAG: declare dllimport i8* @__cxa_allocate_exception(i32)
 // CHECK-DYNAMIC-IA-IMPORT-DAG: declare dllimport i8* @__cxa_allocate_exception(i32)