From fa2eac54e690928592a2bd6c1f8ee0f9b1923d5e Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Mon, 29 Apr 2013 22:25:40 +0000
Subject: [PATCH] Emit the TLS initialization function pointers into the
 correct section.

The `llvm.tls_init_funcs' (created by the front-end) holds pointers to the TLS
initialization functions. These need to be placed into the correct section so
that they are run before `main()'.

<rdar://problem/13733006>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180737 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/AsmPrinter.h     |  1 +
 lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index c2fd6ce3679..4ecc7ade719 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -486,6 +486,7 @@ namespace llvm {
                             unsigned uid) const;
     void EmitLLVMUsedList(const ConstantArray *InitList);
     void EmitXXStructorList(const Constant *List, bool isCtor);
+    void EmitTLSInitFuncs(const ConstantArray *InitList);
     GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);
   };
 }
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 84162ace418..4a71ad33373 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1254,6 +1254,11 @@ bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
     return true;
   }
 
+  if (GV->getName() == "llvm.tls_init_funcs") {
+    EmitTLSInitFuncs(cast<ConstantArray>(GV->getInitializer()));
+    return true;
+  }
+
   return false;
 }
 
@@ -1320,6 +1325,16 @@ void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
   }
 }
 
+/// EmitTLSInitFuncs - Emit the TLS initialization functions.
+void AsmPrinter::EmitTLSInitFuncs(const ConstantArray *InitList) {
+  const DataLayout *TD = TM.getDataLayout();
+  OutStreamer.SwitchSection(getObjFileLowering().getTLSThreadInitSection());
+  EmitAlignment(Log2_32(TD->getPointerPrefAlignment()));
+  for (unsigned I = 0, E = InitList->getNumOperands(); I != E; ++I)
+    EmitGlobalConstant(
+      dyn_cast<Constant>(InitList->getOperand(I)->stripPointerCasts()));
+}
+
 //===--------------------------------------------------------------------===//
 // Emission and print routines
 //