[llvm] r185484 - Debug Info: use module flag to set up Dwarf version.
David Blaikie
dblaikie at gmail.com
Mon Jul 8 16:08:57 PDT 2013
On Mon, Jul 8, 2013 at 3:49 PM, Manman Ren <mren at apple.com> wrote:
>
> On Jul 3, 2013, at 6:31 PM, Eric Christopher wrote:
>
>> On Wed, Jul 3, 2013 at 6:28 PM, David Blaikie <dblaikie at gmail.com> wrote:
>>>
>>> On Jul 3, 2013 5:35 PM, "Eric Christopher" <echristo at gmail.com> wrote:
>>>>
>>>> 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
>>>> :)
>>>
>>> I think we could still make that claim even if its a module flag. If you
>>> have debug info metadata and no flag: invalid. If you don't have any debug
>>> info metadata, we shouldn't care what the flag value is,
>>>
>>
>> Sure. Can do. I am in favor of Module having a function to look up an
>> attribute marked by key. I assume that was just an oversight.
>>
>> Manman: Can you please make all of these changes?
>
> I can definitely add a helper function in Module to query a module flag given a key.
> If we say a module without "Dwarf Version" flag is invalid, we need to update all the existing test cases.
I don't think we have to do that... we can still have a helper
function that queries a given flag & just returns some "nonvalue" or
default value if the module metadata isn't present.
> If we are going to use a metadata field in each DICompileUnit in the long run, I would prefer
> to switch to that now.
Due to a lack of clear recollection of prior discussions on the
subject, I'm less clear on whether there's any overwhelming reason not
to do this, so I can't really veto it.
>
> Manman
>
>> Thanks.
>>
>> -eric
>>
>>>>
>>>> -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}
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> llvm-commits mailing list
>>>>>> llvm-commits at cs.uiuc.edu
>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> llvm-commits mailing list
>>>>> llvm-commits at cs.uiuc.edu
>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>>>
>
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