From 1b68a68c0409cb30dcdfbac1d04a6d5541dedd36 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 1 May 2014 12:45:43 +0000
Subject: [PATCH] Don't force symbols to be globals in .thumb_set.

We currently force symbols to be globals in .thumb_set. The intent
seems to be that given

.thumb_set foo, bar

we emit an undefined symbol to bar if it is never defined. The side
effect is that we mark bar as global, even if it is defined, which gas
does not.

Producing an undefined reference to bar is a general difference from MC and gas.
For example, given

a = b

gas will produce an undefined reference to b, MC will not. I would be surprised
if any code depends on this, but it it does, we should fix the general
difference, not special case .thumb_set.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207757 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../ARM/MCTargetDesc/ARMELFStreamer.cpp       |  7 ++----
 test/MC/ARM/thumb_set.s                       | 25 ++++++++-----------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index e55aa667134..3f5f42318ff 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -1003,11 +1003,8 @@ ARMTargetELFStreamer::AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *S) {
 
 void ARMTargetELFStreamer::emitThumbSet(MCSymbol *Symbol, const MCExpr *Value) {
   if (const MCSymbolRefExpr *SRE = dyn_cast<MCSymbolRefExpr>(Value)) {
-    // FIXME: Doing a lookup in here is a hack.
-    MCSymbol *Sym =
-        getStreamer().getContext().LookupSymbol(SRE->getSymbol().getName());
-    if (!Sym->isDefined()) {
-      getStreamer().EmitSymbolAttribute(Sym, MCSA_Global);
+    const MCSymbol &Sym = SRE->getSymbol();
+    if (!Sym.isDefined()) {
       getStreamer().EmitAssignment(Symbol, Value);
       return;
     }
diff --git a/test/MC/ARM/thumb_set.s b/test/MC/ARM/thumb_set.s
index ac4bd328895..d2a0dc04730 100644
--- a/test/MC/ARM/thumb_set.s
+++ b/test/MC/ARM/thumb_set.s
@@ -59,8 +59,6 @@ beta:
 
 	.thumb_set beta, alpha
 
-	.thumb_set alias_undefined, undefined
-
 @ CHECK: Symbol {
 @ CHECK:   Name: alias_arm_func
 @ CHECK:   Value: 0x1
@@ -109,6 +107,16 @@ beta:
 @ CHECK:   Type: Function
 @ CHECK: }
 
+@ CHECK:      Symbol {
+@ CHECK:        Name: badblood
+@ CHECK-NEXT:   Value: 0x0
+@ CHECK-NEXT:   Size: 0
+@ CHECK-NEXT:   Binding: Local
+@ CHECK-NEXT:   Type: Object
+@ CHECK-NEXT:   Other: 0
+@ CHECK-NEXT:   Section: .data
+@ CHECK-NEXT: }
+
 @ CHECK: Symbol {
 @ CHECK:   Name: bedazzle
 @ CHECK:   Value: 0x4
@@ -144,16 +152,3 @@ beta:
 @ CHECK:   Value: 0x5
 @ CHECK:   Type: Function
 @ CHECK: }
-
-@ CHECK: Symbol {
-@ CHECK:   Name: badblood
-@ CHECK:   Value: 0x0
-@ CHECK:   Type: Object
-@ CHECK: }
-
-@ CHECK: Symbol {
-@ CHECK:   Name: undefined
-@ CHECK:   Value: 0x0
-@ CHECK:   Type: None
-@ CHECK: }
-