[CodeGen][Darwin] Set the calling-convention of thread-local variable

initialization functions to 'cxx_fast_tlscc'.

This fixes a bug where instructions calling initialization functions for
thread-local static members of c++ template classes were using calling
convention 'cxx_fast_tlscc' while the called functions weren't annotated
with the calling convention.

rdar://problem/40447463

Differential Revision: https://reviews.llvm.org/D47354

llvm-svn: 333447

1 files changed, 5 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index b608adfe771..9768e71178b 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2450,8 +2450,12 @@ void ItaniumCXXABI::EmitThreadLocalInitFuncs(
     if (InitIsInitFunc) {
       if (Init) {
         llvm::CallInst *CallVal = Builder.CreateCall(Init);
-        if (isThreadWrapperReplaceable(VD, CGM))
+        if (isThreadWrapperReplaceable(VD, CGM)) {
           CallVal->setCallingConv(llvm::CallingConv::CXX_FAST_TLS);
+          llvm::Function *Fn =
+              cast<llvm::Function>(cast<llvm::GlobalAlias>(Init)->getAliasee());
+          Fn->setCallingConv(llvm::CallingConv::CXX_FAST_TLS);
+        }
       }
     } else {
       // Don't know whether we have an init function. Call it if it exists.