[llvm] r185484 - Debug Info: use module flag to set up Dwarf version.
Eric Christopher
echristo at gmail.com
Wed Jul 3 17:35:45 PDT 2013
On Wed, Jul 3, 2013 at 5:29 PM, David Blaikie <dblaikie at gmail.com> wrote:
>
> On Jul 2, 2013 7:06 PM, "Manman Ren" <mren at apple.com> wrote:
>>
>> Author: mren
>> Date: Tue Jul 2 18:40:10 2013
>> New Revision: 185484
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=185484&view=rev
>> Log:
>> Debug Info: use module flag to set up Dwarf version.
>>
>> Correctly handles ref_addr depending on the Dwarf version. Emit Dwarf with
>> version from module flag.
>>
>> TODO: turn on/off features depending on the Dwarf version.
>>
>> Added:
>> llvm/trunk/test/DebugInfo/version.ll
>> Modified:
>> llvm/trunk/include/llvm/CodeGen/AsmPrinter.h
>> llvm/trunk/lib/CodeGen/AsmPrinter/DIE.cpp
>> llvm/trunk/lib/CodeGen/AsmPrinter/DIE.h
>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
>>
>> Modified: llvm/trunk/include/llvm/CodeGen/AsmPrinter.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/AsmPrinter.h?rev=185484&r1=185483&r2=185484&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/include/llvm/CodeGen/AsmPrinter.h (original)
>> +++ llvm/trunk/include/llvm/CodeGen/AsmPrinter.h Tue Jul 2 18:40:10 2013
>> @@ -121,6 +121,8 @@ namespace llvm {
>> public:
>> virtual ~AsmPrinter();
>>
>> + const DwarfDebug *getDwarfDebug() const { return DD; }
>> +
>> /// isVerbose - Return true if assembly output should contain
>> comments.
>> ///
>> bool isVerbose() const { return VerboseAsm; }
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DIE.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DIE.cpp?rev=185484&r1=185483&r2=185484&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DIE.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DIE.cpp Tue Jul 2 18:40:10 2013
>> @@ -12,6 +12,7 @@
>>
>> //===----------------------------------------------------------------------===//
>>
>> #include "DIE.h"
>> +#include "DwarfDebug.h"
>> #include "llvm/ADT/Twine.h"
>> #include "llvm/CodeGen/AsmPrinter.h"
>> #include "llvm/IR/DataLayout.h"
>> @@ -331,6 +332,16 @@ void DIEEntry::EmitValue(AsmPrinter *AP,
>> AP->EmitInt32(Entry->getOffset());
>> }
>>
>> +unsigned DIEEntry::getRefAddrSize(AsmPrinter *AP) {
>> + // 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.
>> + if (AP->getDwarfDebug()->getDwarfVersion() == 2)
>> + return AP->getDataLayout().getPointerSize();
>> + return sizeof(int32_t);
>> +}
>
> This seems like a slightly strange place for this function - it also doesn't
> need any access to private members of DIEEntry. As it's a generic debug info
> utility function, could it go somewhere more central than DIEEntry? (If its
> needed from other places, which it seems to be)
>
>> +
>> #ifndef NDEBUG
>> void DIEEntry::print(raw_ostream &O) const {
>> O << format("Die: 0x%lx", (long)(intptr_t)Entry);
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DIE.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DIE.h?rev=185484&r1=185483&r2=185484&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DIE.h (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DIE.h Tue Jul 2 18:40:10 2013
>> @@ -365,9 +365,13 @@ namespace llvm {
>> /// SizeOf - Determine size of debug information entry in bytes.
>> ///
>> virtual unsigned SizeOf(AsmPrinter *AP, unsigned Form) const {
>> - return sizeof(int32_t);
>> + return Form == dwarf::DW_FORM_ref_addr ? getRefAddrSize(AP) :
>> + sizeof(int32_t);
>> }
>>
>> + /// Returns size of a ref_addr entry.
>> + static unsigned getRefAddrSize(AsmPrinter *AP);
>> +
>> // Implement isa/cast/dyncast.
>> static bool classof(const DIEValue *E) { return E->getType() ==
>> isEntry; }
>>
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=185484&r1=185483&r2=185484&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Tue Jul 2 18:40:10
>> 2013
>> @@ -162,6 +162,21 @@ DIType DbgVariable::getType() const {
>>
>> } // end llvm namespace
>>
>> +/// Return Dwarf Version by checking module flags.
>> +static unsigned getDwarfVersionFromModule(const Module *M) {
>> + SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
>> + M->getModuleFlagsMetadata(ModuleFlags);
>> + for (unsigned I = 0, E = ModuleFlags.size(); I < E; ++I) {
>> + const Module::ModuleFlagEntry &MFE = ModuleFlags[I];
>> + StringRef Key = MFE.Key->getString();
>> + Value *Val = MFE.Val;
>> +
>> + if (Key == "Dwarf Version")
>> + return cast<ConstantInt>(Val)->getZExtValue();
>> + }
>> + return dwarf::DWARF_VERSION;
>
> Do we not have a better way to query module flags? Perhaps we should add
> one?
>
> Is there any need to support debug info generation for modules that lack
> this flag? Seems we could just consider that to be invalid?
>
Icky. Either we need to autoupgrade modules that come in to specify a
dwarf version or leave this sort of thing around. Admittedly if we
stored it in the CU we could call it an incompatible debug info change
:)
-eric
>> +}
>> +
>> DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
>> : Asm(A), MMI(Asm->MMI), FirstCU(0),
>> AbbreviationsSet(InitAbbreviationsSetSize),
>> @@ -204,6 +219,8 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Mo
>> else
>> HasSplitDwarf = SplitDwarf == Enable ? true : false;
>>
>> + DwarfVersion = getDwarfVersionFromModule(MMI->getModule());
>> +
>> {
>> NamedRegionTimer T(DbgTimerName, DWARFGroupName,
>> TimePassesIsEnabled);
>> beginModule();
>> @@ -1900,7 +1917,8 @@ void DwarfDebug::emitDIE(DIE *Die, std::
>> DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder :
>> InfoHolder;
>> Addr += Holder.getCUOffset(Origin->getCompileUnit());
>> }
>> - Asm->EmitInt32(Addr);
>> + Asm->OutStreamer.EmitIntValue(Addr,
>> + Form == dwarf::DW_FORM_ref_addr ? DIEEntry::getRefAddrSize(Asm)
>> : 4);
>> break;
>> }
>> case dwarf::DW_AT_ranges: {
>> @@ -1984,7 +2002,7 @@ void DwarfUnits::emitUnits(DwarfDebug *D
>> Asm->OutStreamer.AddComment("Length of Compilation Unit Info");
>> Asm->EmitInt32(ContentSize);
>> Asm->OutStreamer.AddComment("DWARF version number");
>> - Asm->EmitInt16(dwarf::DWARF_VERSION);
>> + Asm->EmitInt16(DD->getDwarfVersion());
>> Asm->OutStreamer.AddComment("Offset Into Abbrev. Section");
>>
>> Asm->EmitSectionOffset(Asm->GetTempSymbol(ASection->getLabelBeginName()),
>> ASectionSym);
>> @@ -2225,7 +2243,7 @@ void DwarfDebug::emitDebugPubnames() {
>> Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubnames_begin", ID));
>>
>> Asm->OutStreamer.AddComment("DWARF Version");
>> - Asm->EmitInt16(dwarf::DWARF_VERSION);
>> + Asm->EmitInt16(DwarfVersion);
>>
>> Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
>> Asm->EmitSectionOffset(Asm->GetTempSymbol(ISec->getLabelBeginName(),
>> ID),
>> @@ -2272,7 +2290,7 @@ void DwarfDebug::emitDebugPubTypes() {
>> TheCU->getUniqueID()));
>>
>> if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DWARF Version");
>> - Asm->EmitInt16(dwarf::DWARF_VERSION);
>> + Asm->EmitInt16(DwarfVersion);
>>
>> Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
>> const MCSection *ISec =
>> Asm->getObjFileLowering().getDwarfInfoSection();
>> @@ -2553,7 +2571,7 @@ void DwarfDebug::emitDebugInlineInfo() {
>> Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_inlined_begin",
>> 1));
>>
>> Asm->OutStreamer.AddComment("Dwarf Version");
>> - Asm->EmitInt16(dwarf::DWARF_VERSION);
>> + Asm->EmitInt16(DwarfVersion);
>> Asm->OutStreamer.AddComment("Address Size (in bytes)");
>> Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
>>
>>
>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h?rev=185484&r1=185483&r2=185484&view=diff
>>
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h (original)
>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.h Tue Jul 2 18:40:10
>> 2013
>> @@ -407,6 +407,8 @@ class DwarfDebug {
>> bool HasDwarfAccelTables;
>> bool HasSplitDwarf;
>>
>> + unsigned DwarfVersion;
>> +
>> // Separated Dwarf Variables
>> // In general these will all be for bits that are left in the
>> // original object file, rather than things that are meant
>> @@ -650,6 +652,9 @@ public:
>> /// \brief Returns whether or not to change the current debug info for
>> the
>> /// split dwarf proposal support.
>> bool useSplitDwarf() { return HasSplitDwarf; }
>> +
>> + /// Returns the Dwarf Version.
>> + unsigned getDwarfVersion() const { return DwarfVersion; }
>> };
>> } // End of namespace llvm
>>
>>
>> Added: llvm/trunk/test/DebugInfo/version.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/version.ll?rev=185484&view=auto
>>
>> ==============================================================================
>> --- llvm/trunk/test/DebugInfo/version.ll (added)
>> +++ llvm/trunk/test/DebugInfo/version.ll Tue Jul 2 18:40:10 2013
>> @@ -0,0 +1,27 @@
>> +; RUN: llc -O0 < %s | FileCheck %s
>> +; Make sure we are generating DWARF version 3 when module flag says so.
>> +; CHECK: .short 3 ## DWARF version number
>> +
>> +define i32 @main() #0 {
>> +entry:
>> + %retval = alloca i32, align 4
>> + store i32 0, i32* %retval
>> + ret i32 0, !dbg !10
>> +}
>> +
>> +attributes #0 = { nounwind uwtable "less-precise-fpmad"="false"
>> "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true"
>> "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false"
>> "use-soft-float"="false" }
>> +
>> +!llvm.dbg.cu = !{!0}
>> +!llvm.module.flags = !{!9}
>> +
>> +!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version
>> 3.4 (trunk 185475)", i1 false, metadata !"", i32 0, metadata !2, metadata
>> !2, metadata !3, metadata !2, metadata !2, metadata !""} ; [
>> DW_TAG_compile_unit ]
>> +!1 = metadata !{metadata !"CodeGen/dwarf-version.c", metadata !"test"}
>> +!2 = metadata !{i32 0}
>> +!3 = metadata !{metadata !4}
>> +!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"main",
>> metadata !"main", metadata !"", i32 6, metadata !6, i1 false, i1 true, i32
>> 0, i32 0, null, i32 256, i1 false, i32 ()* @main, null, null, metadata !2,
>> i32 6} ; [ DW_TAG_subprogram ] [line 6] [def] [main]
>> +!5 = metadata !{i32 786473, metadata !1} ; [ DW_TAG_file_type ]
>> +!6 = metadata !{i32 786453, i32 0, i32 0, metadata !"", i32 0, i64 0, i64
>> 0, i64 0, i32 0, null, metadata !7, i32 0, i32 0} ; [ DW_TAG_subroutine_type
>> ] [line 0, size 0, align 0, offset 0] [from ]
>> +!7 = metadata !{metadata !8}
>> +!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32,
>> i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32,
>> align 32, offset 0, enc DW_ATE_signed]
>> +!9 = metadata !{i32 2, metadata !"Dwarf Version", i32 3}
>> +!10 = metadata !{i32 7, i32 0, metadata !4, null}
>>
>>
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