From d96c72a14cf327af98cbc7d3491f7a2248f5137d Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@gmail.com>
Date: Thu, 17 Jan 2013 02:59:59 +0000
Subject: [PATCH] Add the DW_AT_GNU_addr_base for the skeleton cu. Add support
 for emitting the dwarf32 version of DW_FORM_sec_offset and correct
 disassembler support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172698 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DIE.cpp        | 2 ++
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 6 +++++-
 lib/DebugInfo/DWARFFormValue.cpp      | 6 ++----
 test/DebugInfo/X86/fission-cu.ll      | 1 +
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/DIE.cpp b/lib/CodeGen/AsmPrinter/DIE.cpp
index 0a659c2a09c..5d1fd83ad21 100644
--- a/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -193,6 +193,7 @@ void DIEInteger::EmitValue(AsmPrinter *Asm, unsigned Form) const {
   case dwarf::DW_FORM_data1: Size = 1; break;
   case dwarf::DW_FORM_ref2:  // Fall thru
   case dwarf::DW_FORM_data2: Size = 2; break;
+  case dwarf::DW_FORM_sec_offset: // Fall thru
   case dwarf::DW_FORM_ref4:  // Fall thru
   case dwarf::DW_FORM_data4: Size = 4; break;
   case dwarf::DW_FORM_ref8:  // Fall thru
@@ -218,6 +219,7 @@ unsigned DIEInteger::SizeOf(AsmPrinter *AP, unsigned Form) const {
   case dwarf::DW_FORM_data1: return sizeof(int8_t);
   case dwarf::DW_FORM_ref2:  // Fall thru
   case dwarf::DW_FORM_data2: return sizeof(int16_t);
+  case dwarf::DW_FORM_sec_offset: // Fall thru
   case dwarf::DW_FORM_ref4:  // Fall thru
   case dwarf::DW_FORM_data4: return sizeof(int32_t);
   case dwarf::DW_FORM_ref8:  // Fall thru
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 1813132f877..077aab368d3 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2443,7 +2443,11 @@ CompileUnit *DwarfDebug::constructSkeletonCU(const MDNode *N) {
   // FIXME: This should be the .dwo file.
   NewCU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name, FN);
 
-  // FIXME: We also need DW_AT_addr_base and DW_AT_dwo_id.
+  // FIXME: We also need DW_AT_dwo_id.
+
+  // FIXME: The addr base should be relative for each compile unit, however,
+  // this one is going to be 0 anyhow.
+  NewCU->addUInt(Die, dwarf::DW_AT_GNU_addr_base, dwarf::DW_FORM_sec_offset, 0);
 
   // 2.17.1 requires that we use DW_AT_low_pc for a single entry point
   // into an entity. We're using 0, or a NULL label for this.
diff --git a/lib/DebugInfo/DWARFFormValue.cpp b/lib/DebugInfo/DWARFFormValue.cpp
index d1bcf96f7fe..ea59c1d780d 100644
--- a/lib/DebugInfo/DWARFFormValue.cpp
+++ b/lib/DebugInfo/DWARFFormValue.cpp
@@ -173,10 +173,8 @@ DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
       indirect = true;
       break;
     case DW_FORM_sec_offset:
-      if (cu->getAddressByteSize() == 4)
-        Value.uval = data.getU32(offset_ptr);
-      else
-        Value.uval = data.getU64(offset_ptr);
+      // FIXME: This is 64-bit for DWARF64.
+      Value.uval = data.getU32(offset_ptr);
       break;
     case DW_FORM_flag_present:
       Value.uval = 1;
diff --git a/test/DebugInfo/X86/fission-cu.ll b/test/DebugInfo/X86/fission-cu.ll
index ef5f9586a21..7e80d8f2964 100644
--- a/test/DebugInfo/X86/fission-cu.ll
+++ b/test/DebugInfo/X86/fission-cu.ll
@@ -22,6 +22,7 @@
 ; CHECK: .debug_info contents:
 ; CHECK: DW_TAG_compile_unit
 ; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000000] = "baz.c")
+; CHECK: DW_AT_GNU_addr_base [DW_FORM_sec_offset]                   (0x0000000000000000)
 ; CHECK: DW_AT_low_pc [DW_FORM_addr]       (0x0000000000000000)
 ; CHECK: DW_AT_stmt_list [DW_FORM_data4]   (0x00000000)
 ; CHECK: DW_AT_comp_dir [DW_FORM_strp]     ( .debug_str[0x00000006] = "/usr/local/google/home/echristo/tmp")
-- 
2.34.1