From 56ebe5082da7411fb37479e230b52735f77cff35 Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Sun, 19 Apr 2009 21:05:03 +0000
Subject: [PATCH] PR3853: Add CodeGen support for __thread.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69545 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGDecl.cpp          |  9 +++------
 lib/CodeGen/CodeGenModule.cpp   |  8 +++-----
 test/CodeGen/thread-specifier.c | 10 ++++++++++
 3 files changed, 16 insertions(+), 11 deletions(-)
 create mode 100644 test/CodeGen/thread-specifier.c

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index c9e47eba77..681d8f68af 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -63,10 +63,6 @@ void CodeGenFunction::EmitBlockVarDecl(const VarDecl &D) {
   if (D.hasAttr<AsmLabelAttr>())
     CGM.ErrorUnsupported(&D, "__asm__");
   
-  // We don't support __thread yet.
-  if (D.isThreadSpecified())
-    CGM.ErrorUnsupported(&D, "thread local ('__thread') variable", true);
-  
   switch (D.getStorageClass()) {
   case VarDecl::None:
   case VarDecl::Auto:
@@ -110,7 +106,8 @@ CodeGenFunction::CreateStaticBlockVarDecl(const VarDecl &D,
   const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
   return new llvm::GlobalVariable(LTy, Ty.isConstant(getContext()), Linkage,
                                   llvm::Constant::getNullValue(LTy), Name,
-                                  &CGM.getModule(), 0, Ty.getAddressSpace());
+                                  &CGM.getModule(), D.isThreadSpecified(),
+                                  Ty.getAddressSpace());
 }
 
 void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) { 
@@ -145,7 +142,7 @@ void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) {
         
         GV = new llvm::GlobalVariable(Init->getType(), OldGV->isConstant(),
                                       OldGV->getLinkage(), Init, "",
-                                      &CGM.getModule(), 0, 
+                                      &CGM.getModule(), D.isThreadSpecified(),
                                       D.getType().getAddressSpace());
 
         // Steal the name of the old global
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index a517d81545..1a52ba2ab1 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -656,10 +656,6 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
     return llvm::ConstantExpr::getBitCast(Entry, Ty);
   }
   
-  // We don't support __thread yet.
-  if (D && D->isThreadSpecified())
-    ErrorUnsupported(D, "thread local ('__thread') variable", true);
-  
   // This is the first use or definition of a mangled name.  If there is a
   // deferred decl with this name, remember that we need to emit it at the end
   // of the file.
@@ -676,7 +672,7 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
     new llvm::GlobalVariable(Ty->getElementType(), false, 
                              llvm::GlobalValue::ExternalLinkage,
                              0, "", &getModule(), 
-                             0, Ty->getAddressSpace());
+                             false, Ty->getAddressSpace());
   GV->setName(MangledName);
 
   // Handle things which are present even on external declarations.
@@ -691,6 +687,8 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName,
 
     if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>())
       GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
+
+    GV->setThreadLocal(D->isThreadSpecified());
   }
   
   return Entry = GV;
diff --git a/test/CodeGen/thread-specifier.c b/test/CodeGen/thread-specifier.c
new file mode 100644
index 0000000000..08992a6e22
--- /dev/null
+++ b/test/CodeGen/thread-specifier.c
@@ -0,0 +1,10 @@
+// RUN: clang-cc -emit-llvm -o - %s | grep thread_local | count 4
+
+__thread int a;
+extern __thread int b;
+int c() { return &b; }
+int d() {
+  __thread static int e;
+  __thread static union {float a; int b;} f = {.b = 1};
+}
+
-- 
2.40.0