[llvm] r185484 - Debug Info: use module flag to set up Dwarf version.
David Blaikie
dblaikie at gmail.com
Wed Jul 3 18:28:52 PDT 2013
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,
>
> -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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> >> llvm-commits at cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> >
> >
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> >
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