From c385367909ab343dcc0a1a63267adb4786f9ebe5 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Sun, 25 May 2014 12:49:07 +0000
Subject: [PATCH] Emit data or code export directives based on the type.

Currently we look at the Aliasee to decide what type of export
directive to use. It seems better to use the type of the alias
directly. This is similar to how we handle the alias having the
same address but other attributes (linkage, visibility) from the
aliasee.

With this patch it is now possible to do things like

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc"
@foo = global [6 x i8] c"\B8*\00\00\00\C3", section ".text", align 16
@f = dllexport alias i32 (), [6 x i8]* @foo
!llvm.module.flags = !{!0}
!0 = metadata !{i32 6, metadata !"Linker Options", metadata !1}
!1 = metadata !{metadata !2, metadata !3}
!2 = metadata !{metadata !"/DEFAULTLIB:libcmt.lib"}
!3 = metadata !{metadata !"/DEFAULTLIB:oldnames.lib"}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209600 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86AsmPrinter.cpp     | 10 +++-------
 test/CodeGen/X86/dllexport-x86_64.ll |  4 ++++
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/Target/X86/X86AsmPrinter.cpp b/lib/Target/X86/X86AsmPrinter.cpp
index 68e136bd776..1dca5689ade 100644
--- a/lib/Target/X86/X86AsmPrinter.cpp
+++ b/lib/Target/X86/X86AsmPrinter.cpp
@@ -670,16 +670,12 @@ void X86AsmPrinter::EmitEndOfAsmFile(Module &M) {
         DLLExportedGlobals.push_back(getSymbol(&Global));
 
     for (const auto &Alias : M.aliases()) {
-      const GlobalValue *GV = &Alias;
-      if (!GV->hasDLLExportStorageClass())
+      if (!Alias.hasDLLExportStorageClass())
         continue;
 
-      while (const GlobalAlias *A = dyn_cast<GlobalAlias>(GV))
-        GV = A->getAliasee();
-
-      if (isa<Function>(GV))
+      if (Alias.getType()->getElementType()->isFunctionTy())
         DLLExportedFns.push_back(getSymbol(&Alias));
-      else if (isa<GlobalVariable>(GV))
+      else
         DLLExportedGlobals.push_back(getSymbol(&Alias));
     }
 
diff --git a/test/CodeGen/X86/dllexport-x86_64.ll b/test/CodeGen/X86/dllexport-x86_64.ll
index bd099b04223..1347664c71f 100644
--- a/test/CodeGen/X86/dllexport-x86_64.ll
+++ b/test/CodeGen/X86/dllexport-x86_64.ll
@@ -72,6 +72,8 @@ define weak_odr dllexport void @weak1() {
 ; CHECK: weak_alias = f1
 @weak_alias = dllexport alias weak_odr void()* @f1
 
+@blob = global [6 x i8] c"\B8*\00\00\00\C3", section ".text", align 16
+@blob_alias = dllexport alias i32 (), [6 x i8]* @blob
 
 ; CHECK: .section .drectve
 ; WIN32: /EXPORT:Var1,DATA"
@@ -88,6 +90,7 @@ define weak_odr dllexport void @weak1() {
 ; WIN32: /EXPORT:alias2"
 ; WIN32: /EXPORT:alias3"
 ; WIN32: /EXPORT:weak_alias"
+; WIN32: /EXPORT:blob_alias"
 ; MINGW: -export:Var1,data"
 ; MINGW: -export:Var2,data"
 ; MINGW: -export:Var3,data"
@@ -102,3 +105,4 @@ define weak_odr dllexport void @weak1() {
 ; MINGW: -export:alias2"
 ; MINGW: -export:alias3"
 ; MINGW: -export:weak_alias"
+; MINGW: -export:blob_alias"