From e3d75ee2a1c8ea11fd01fc49055d08f2da7f5668 Mon Sep 17 00:00:00 2001
From: Manman Ren <mren@apple.com>
Date: Thu, 4 Apr 2013 00:22:54 +0000
Subject: Debug Info: according to DWARF 2, FORM_ref_addr the same size as an
 address on the target system.

It was hard-coded to 4 bytes before. I can't get llvm to generate a
ref_addr on a reasonably sized testing case.

rdar://problem/13559431


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178722 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DIE.cpp        | 6 ++++++
 lib/CodeGen/AsmPrinter/DIE.h          | 4 +---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 9 ++++++++-
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/DIE.cpp b/lib/CodeGen/AsmPrinter/DIE.cpp
index 57e0acda89..326fbe5567 100644
--- a/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -310,6 +310,12 @@ void DIEEntry::EmitValue(AsmPrinter *AP, unsigned Form) const {
   AP->EmitInt32(Entry->getOffset());
 }
 
+unsigned DIEEntry::SizeOf(AsmPrinter *AP, unsigned Form) const {
+  if (Form == dwarf::DW_FORM_ref_addr)
+    return AP->getDataLayout().getPointerSize();
+  return sizeof(int32_t);
+}
+
 #ifndef NDEBUG
 void DIEEntry::print(raw_ostream &O) {
   O << format("Die: 0x%lx", (long)(intptr_t)Entry);
diff --git a/lib/CodeGen/AsmPrinter/DIE.h b/lib/CodeGen/AsmPrinter/DIE.h
index c332aa2a7d..8d68fd595f 100644
--- a/lib/CodeGen/AsmPrinter/DIE.h
+++ b/lib/CodeGen/AsmPrinter/DIE.h
@@ -336,9 +336,7 @@ namespace llvm {
 
     /// SizeOf - Determine size of debug information entry in bytes.
     ///
-    virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const {
-      return sizeof(int32_t);
-    }
+    virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const;
 
     // Implement isa/cast/dyncast.
     static bool classof(const DIEValue *E) { return E->getType() == isEntry; }
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d3cb4f9c1c..b6b0bb1237 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1791,7 +1791,14 @@ void DwarfDebug::emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs) {
         DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
         Addr += Holder.getCUOffset(Origin->getCompileUnit());
       }
-      Asm->EmitInt32(Addr);
+      // DWARF4: References that use the attribute form DW_FORM_ref_addr are
+      // specified to be four bytes in the DWARF 32-bit format and eight bytes
+      // in the DWARF 64-bit format, while DWARF Version 2 specifies that such
+      // references have the same size as an address on the target system.
+      // Our current version is version 2.
+      Asm->OutStreamer.EmitIntValue(Addr,
+          Form == dwarf::DW_FORM_ref_addr ?
+          Asm->getDataLayout().getPointerSize() : 4);
       break;
     }
     case dwarf::DW_AT_ranges: {
-- 
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