DebugInfo: Do not use the DWARF Version for the .debug_pubnames or .debug_pubtypes version field

[majnemer]

Summary

LLVM would generate DWARF with version 3 in the .debug_pubname and
.debug_pubtypes version fields. This would lead SGI dwarfdump to fail
parsing the DWARF with (in the instance of .debug_pubnames) would exit
with:
dwarfdump ERROR: dwarf_get_globals: DW_DLE_PUBNAMES_VERSION_ERROR (123)

This fixes PR16950.

[echristo]

LGTM.

Thanks.

[echristo]

FWIW llvm-commits for the back end patches next time :)

-eric

include/llvm/Support/Dwarf.h

enum llvm_dwarf_constants {
   // llvm mock tags
   DW_TAG_invalid = ~0U,                 // Tag for invalid results.
 
   DW_TAG_auto_variable = 0x100,         // Tag for local (auto) variables.
   DW_TAG_arg_variable = 0x101,          // Tag for argument variables.
 
   DW_TAG_user_base = 0x1000,            // Recommended base for user tags.
 
-  DW_CIE_VERSION = 1                    // Common frame information version.
+  DW_CIE_VERSION = 1,                   // Common frame information version.
+  DW_PUBTYPES_VERSION = 2,              // Section version number for .debug_pubtypes.
+  DW_PUBNAMES_VERSION = 2               // Section version number for .debug_pubnames.
 };
 
 
 // Special ID values that distinguish a CIE from a FDE in DWARF CFI.
 // Not inside an enum because a 64-bit value is needed.
 const uint32_t DW_CIE_ID = UINT32_MAX;
 const uint64_t DW64_CIE_ID = UINT64_MAX;
 

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/MD5.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/ValueHandle.h"
 #include "llvm/Target/TargetFrameLowering.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
for (CUMapType::iterator I = CUMap.begin(), E = CUMap.end(); I != E; ++I) {
 
     Asm->OutStreamer.AddComment("Length of Public Names Info");
     Asm->EmitLabelDifference(Asm->GetTempSymbol("pubnames_end", ID),
                              Asm->GetTempSymbol("pubnames_begin", ID), 4);
 
     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubnames_begin", ID));
 
     Asm->OutStreamer.AddComment("DWARF Version");
-    Asm->EmitInt16(DwarfVersion);
+    Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
 
     Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
     Asm->EmitSectionOffset(Asm->GetTempSymbol(ISec->getLabelBeginName(), ID),
                            DwarfInfoSectionSym);
 
     Asm->OutStreamer.AddComment("Compilation Unit Length");
     Asm->EmitLabelDifference(Asm->GetTempSymbol(ISec->getLabelEndName(), ID),
                              Asm->GetTempSymbol(ISec->getLabelBeginName(), ID),
for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
     Asm->EmitLabelDifference(
       Asm->GetTempSymbol("pubtypes_end", TheCU->getUniqueID()),
       Asm->GetTempSymbol("pubtypes_begin", TheCU->getUniqueID()), 4);
 
     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_begin",
                                                   TheCU->getUniqueID()));
 
     if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DWARF Version");
-    Asm->EmitInt16(DwarfVersion);
+    Asm->EmitInt16(dwarf::DW_PUBTYPES_VERSION);
 
     Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
     const MCSection *ISec = Asm->getObjFileLowering().getDwarfInfoSection();
     Asm->EmitSectionOffset(Asm->GetTempSymbol(ISec->getLabelBeginName(),
                                               TheCU->getUniqueID()),
                            DwarfInfoSectionSym);
 
     Asm->OutStreamer.AddComment("Compilation Unit Length");

test/DebugInfo/dwarf-public-names.ll

 ;   void global_namespace_function() {
 ;     global_variable.member_function();
 ;   }
 ;   int global_namespace_variable = 1;
 ; }
 
 ; Skip the output to the header of the pubnames section.
 ; CHECK: debug_pubnames
+; CHECK: Version:               2
 
 ; Check for each name in the output.
 ; CHECK: global_namespace_variable
 ; CHECK: global_namespace_function
 ; CHECK: static_member_function
 ; CHECK: global_variable
 ; CHECK: global_function
 ; CHECK: member_function