From 0de6255877753001ce845e4d0bc574a24286329d Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 27 Nov 2013 15:52:11 +0000
Subject: Use the same tls section name as msvc.

We currently error in clang with:
"error: thread-local storage is unsupported for the current target", but we
can start to get the llvm level ready.

When compiling

template<typename T>
struct foo {
  static __declspec(thread) int bar;
};
template<typename T>
__declspec(therad) int foo<T>::bar;
template struct foo<int>;

msvc produces

SECTION HEADER #3
   .tls$ name
       0 physical address
       0 virtual address
       4 size of raw data
     12F file pointer to raw data (0000012F to 00000132)
       0 file pointer to relocation table
       0 file pointer to line numbers
       0 number of relocations
       0 number of line numbers
C0301040 flags
         Initialized Data
         COMDAT; sym= "public: static int foo<int>::bar" (?bar@?$foo@H@@2HA)
         4 byte align
         Read Write

gcc produces a ".data$__emutls_v.<symbol>" for the testcase with
__declspec(thread) replaced with thread_local.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195849 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/TargetLoweringObjectFileImpl.cpp |  2 +-
 test/MC/COFF/weak-symbol.ll                  | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 229ccfae28..25d8cdc439 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -744,7 +744,7 @@ static const char *getCOFFSectionNameForUniqueGlobal(SectionKind Kind) {
   if (Kind.isBSS ())
     return ".bss";
   if (Kind.isThreadLocal())
-    return ".tls";
+    return ".tls$";
   if (Kind.isWriteable())
     return ".data";
   return ".rdata";
diff --git a/test/MC/COFF/weak-symbol.ll b/test/MC/COFF/weak-symbol.ll
index f23063e59c..c06692ed90 100644
--- a/test/MC/COFF/weak-symbol.ll
+++ b/test/MC/COFF/weak-symbol.ll
@@ -36,3 +36,13 @@ define weak void @f() section ".sect" {
 ; X64: .globl a
 ; X64: .zero 12
 @a = weak unnamed_addr constant { i32, i32, i32 } { i32 0, i32 0, i32 0}, section ".data"
+
+; X86:  .section        .tls$,"w",discard,_b
+; X86:  .globl  _b
+; X86:  .long   0
+;
+; X64:  .section        .tls$,"w",discard,b
+; X64:  .globl  b
+; X64:  .long   0
+
+@b = weak_odr thread_local global i32 0, align 4
-- 
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