From 16238d90b2755009fa6cfc752863ef80a5adefe4 Mon Sep 17 00:00:00 2001
From: Frederic Riss <friss@apple.com>
Date: Thu, 25 Jun 2015 21:57:33 +0000
Subject: [PATCH] IAS: Use the root macro instanciation for location

r224810 fixed the handling of macro debug locations in AsmParser. This patch
fixes the logic to actually do what was intended: it uses the first macro of
the macro stack instead of the last one. The updated testcase shows that the
current scheme doesn't work when macro instanciations are nested and multiple
files are used.

Reviewers: compnerd

Differential Revision: http://reviews.llvm.org/D10463

llvm-svn: 240705
---
 llvm/lib/MC/MCParser/AsmParser.cpp              |  4 ++--
 llvm/test/DebugInfo/X86/asm-macro-line-number.s | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 2245a466e62ab..04d141389c923 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -1646,8 +1646,8 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info,
     if (ActiveMacros.empty())
       Line = SrcMgr.FindLineNumber(IDLoc, CurBuffer);
     else
-      Line = SrcMgr.FindLineNumber(ActiveMacros.back()->InstantiationLoc,
-                                   ActiveMacros.back()->ExitBuffer);
+      Line = SrcMgr.FindLineNumber(ActiveMacros.front()->InstantiationLoc,
+                                   ActiveMacros.front()->ExitBuffer);
 
     // If we previously parsed a cpp hash file line comment then make sure the
     // current Dwarf File is for the CppHashFilename if not then emit the
diff --git a/llvm/test/DebugInfo/X86/asm-macro-line-number.s b/llvm/test/DebugInfo/X86/asm-macro-line-number.s
index 0f51dbb6440a2..8b0843d06138b 100644
--- a/llvm/test/DebugInfo/X86/asm-macro-line-number.s
+++ b/llvm/test/DebugInfo/X86/asm-macro-line-number.s
@@ -3,12 +3,18 @@
 # 1 "reduced.S"
 # 1 "<built-in>" 1
 # 1 "reduced.S" 2
+# 200 "macros.h"
 
  .macro return arg
   movl %eax, \arg
   retl
  .endm
 
+ .macro return2 arg
+  return \arg
+ .endm
+
+# 7 "reduced.S"
 function:
  return 0
 
@@ -18,3 +24,11 @@ function:
 # CHECK: .loc 2 8 0
 # CHECK: retl
 
+# 42 "reduced.S"
+function2:
+ return2 0
+
+# CHECK: .loc 2 43 0
+# CHECK: movl %eax, 0
+# CHECK: .loc 2 43 0
+# CHECK: retl