From 597a7664e1bbe2ea5f757eb6e853bd1d2fe98d6c Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 4 May 2011 17:44:06 +0000
Subject: [PATCH] Producing a DW_FORM_addr for DW_AT_stmt_list is probably
 correct, but it is both inefficient and unexpected by dwarfdump. Change to a
 DW_FORM_data4.

While in here, change the predicate name to reflect that the position
is not really absolute (it is an offset), just that the linker needs a
relocation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130846 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/MC/MCAsmInfo.h           | 10 +++++-----
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp |  4 ++--
 lib/MC/MCAsmInfo.cpp                  |  2 +-
 lib/MC/MCAsmInfoDarwin.cpp            |  2 +-
 test/DebugInfo/stmt-list.ll           | 19 +++++++++++++++++++
 5 files changed, 28 insertions(+), 9 deletions(-)
 create mode 100644 test/DebugInfo/stmt-list.ll

diff --git a/include/llvm/MC/MCAsmInfo.h b/include/llvm/MC/MCAsmInfo.h
index 87331613945..2ed5c0a47a2 100644
--- a/include/llvm/MC/MCAsmInfo.h
+++ b/include/llvm/MC/MCAsmInfo.h
@@ -279,9 +279,9 @@ namespace llvm {
     /// DwarfSectionOffsetDirective - Special section offset directive.
     const char* DwarfSectionOffsetDirective; // Defaults to NULL
 
-    /// DwarfUsesAbsoluteLabelForStmtList - True if DW_AT_stmt_list needs
-    /// absolute label instead of offset.
-    bool DwarfUsesAbsoluteLabelForStmtList;  // Defaults to true;
+    /// DwarfRequiresRelocationForStmtList - True if DW_AT_stmt_list needs
+    /// a relocation to the correct offset.
+    bool DwarfRequiresRelocationForStmtList;  // Defaults to true;
 
     // DwarfUsesLabelOffsetDifference - True if Dwarf2 output can
     // use EmitLabelOffsetDifference.
@@ -476,8 +476,8 @@ namespace llvm {
     const char *getDwarfSectionOffsetDirective() const {
       return DwarfSectionOffsetDirective;
     }
-    bool doesDwarfUsesAbsoluteLabelForStmtList() const {
-      return DwarfUsesAbsoluteLabelForStmtList;
+    bool doesDwarfRequireRelocationForStmtList() const {
+      return DwarfRequiresRelocationForStmtList;
     }
     bool doesDwarfUsesLabelOffsetForRanges() const {
       return DwarfUsesLabelOffsetForRanges;
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index fe713d4bf52..2e563dd084c 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -896,8 +896,8 @@ void DwarfDebug::constructCompileUnit(const MDNode *N) {
   NewCU->addUInt(Die, dwarf::DW_AT_entry_pc, dwarf::DW_FORM_addr, 0);
   // DW_AT_stmt_list is a offset of line number information for this
   // compile unit in debug_line section.
-  if (Asm->MAI->doesDwarfUsesAbsoluteLabelForStmtList())
-    NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_addr,
+  if(Asm->MAI->doesDwarfRequireRelocationForStmtList())
+    NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
                     Asm->GetTempSymbol("section_line"));
   else
     NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp
index 541dd080acc..c6d6c1b2134 100644
--- a/lib/MC/MCAsmInfo.cpp
+++ b/lib/MC/MCAsmInfo.cpp
@@ -76,7 +76,7 @@ MCAsmInfo::MCAsmInfo() {
   ExceptionsType = ExceptionHandling::None;
   DwarfRequiresFrameSection = true;
   DwarfUsesInlineInfoSection = false;
-  DwarfUsesAbsoluteLabelForStmtList = true;
+  DwarfRequiresRelocationForStmtList = true;
   DwarfSectionOffsetDirective = 0;
   DwarfUsesLabelOffsetForRanges = true;
   HasMicrosoftFastStdCallMangling = false;
diff --git a/lib/MC/MCAsmInfoDarwin.cpp b/lib/MC/MCAsmInfoDarwin.cpp
index 4dd1d44af5d..2a470251864 100644
--- a/lib/MC/MCAsmInfoDarwin.cpp
+++ b/lib/MC/MCAsmInfoDarwin.cpp
@@ -56,6 +56,6 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
   HasNoDeadStrip = true;
   HasSymbolResolver = true;
 
-  DwarfUsesAbsoluteLabelForStmtList = false;
+  DwarfRequiresRelocationForStmtList = false;
   DwarfUsesLabelOffsetForRanges = false;
 }
diff --git a/test/DebugInfo/stmt-list.ll b/test/DebugInfo/stmt-list.ll
new file mode 100644
index 00000000000..145649bf459
--- /dev/null
+++ b/test/DebugInfo/stmt-list.ll
@@ -0,0 +1,19 @@
+; RUN: llc -mtriple x86_64-pc-linux-gnu < %s | FileCheck %s
+
+; CHECK:      .section        .debug_line,"",@progbits
+; CHECK-NEXT: .Lsection_line:
+
+; CHECK:      .long   .Lsection_line          # DW_AT_stmt_list
+
+define void @f() {
+entry:
+  ret void
+}
+
+!llvm.dbg.sp = !{!0}
+
+!0 = metadata !{i32 589870, i32 0, metadata !1, metadata !"f", metadata !"f", metadata !"", metadata !1, i32 1, metadata !3, i1 false, i1 true, i32 0, i32 0, i32 0, i32 256, i1 true, void ()* @f, null, null} ; [ DW_TAG_subprogram ]
+!1 = metadata !{i32 589865, metadata !"test2.c", metadata !"/home/espindola/llvm", metadata !2} ; [ DW_TAG_file_type ]
+!2 = metadata !{i32 589841, i32 0, i32 12, metadata !"test2.c", metadata !"/home/espindola/llvm", metadata !"clang version 3.0 ()", i1 true, i1 true, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!3 = metadata !{i32 589845, metadata !1, metadata !"", metadata !1, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !4, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!4 = metadata !{null}
-- 
2.34.1