include/llvm/MC/MCAsmInfo.h | 7 +++++++ lib/MC/MCAsmInfo.cpp | 1 + lib/MC/MCDwarf.cpp | 16 ++++++++++------ lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp | 5 +++++ 4 files changed, 23 insertions(+), 6 deletions(-) diff --git a/include/llvm/MC/MCAsmInfo.h b/include/llvm/MC/MCAsmInfo.h index 8672b8d..b189956 100644 --- a/include/llvm/MC/MCAsmInfo.h +++ b/include/llvm/MC/MCAsmInfo.h @@ -302,6 +302,10 @@ namespace llvm { /// uses relocations for references to other .debug_* sections. bool DwarfUsesRelocationsAcrossSections; + /// DwarfFDESymbolsUseAbsDiff - true if DWARF FDE symbol reference + /// relocations should be replaced by an absolute difference. + bool DwarfFDESymbolsUseAbsDiff; + /// DwarfRegNumForCFI - True if dwarf register numbers are printed /// instead of symbolic register names in .cfi_* directives. bool DwarfRegNumForCFI; // Defaults to false; @@ -527,6 +531,9 @@ namespace llvm { bool doesDwarfUseRelocationsAcrossSections() const { return DwarfUsesRelocationsAcrossSections; } + bool doDwarfFDESymbolsUseAbsDiff() const { + return DwarfFDESymbolsUseAbsDiff; + } bool useDwarfRegNumForCFI() const { return DwarfRegNumForCFI; } diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp index 16506fe..0bba0a2 100644 --- a/lib/MC/MCAsmInfo.cpp +++ b/lib/MC/MCAsmInfo.cpp @@ -85,6 +85,7 @@ MCAsmInfo::MCAsmInfo() { SupportsDebugInformation = false; ExceptionsType = ExceptionHandling::None; DwarfUsesRelocationsAcrossSections = true; + DwarfFDESymbolsUseAbsDiff = false; DwarfRegNumForCFI = false; HasMicrosoftFastStdCallMangling = false; NeedsDwarfSectionOffsetDirective = false; diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp index 1e5c2e3..9fd13ab 100644 --- a/lib/MC/MCDwarf.cpp +++ b/lib/MC/MCDwarf.cpp @@ -836,8 +836,9 @@ static unsigned getSizeForEncoding(MCStreamer &streamer, } } -static void EmitSymbol(MCStreamer &streamer, const MCSymbol &symbol, - unsigned symbolEncoding, const char *comment = 0) { +static void EmitFDESymbol(MCStreamer &streamer, const MCSymbol &symbol, + unsigned symbolEncoding, bool isEH, + const char *comment = 0) { MCContext &context = streamer.getContext(); const MCAsmInfo *asmInfo = context.getAsmInfo(); const MCExpr *v = asmInfo->getExprForFDESymbol(&symbol, @@ -845,7 +846,10 @@ static void EmitSymbol(MCStreamer &streamer, const MCSymbol &symbol, streamer); unsigned size = getSizeForEncoding(streamer, symbolEncoding); if (streamer.isVerboseAsm() && comment) streamer.AddComment(comment); - streamer.EmitAbsValue(v, size); + if (asmInfo->doDwarfFDESymbolsUseAbsDiff() && isEH) + streamer.EmitAbsValue(v, size); + else + streamer.EmitValue(v, size); } static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol, @@ -1344,7 +1348,7 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer, unsigned PCEncoding = IsEH ? MOFI->getFDEEncoding(UsingCFI) : (unsigned)dwarf::DW_EH_PE_absptr; unsigned PCSize = getSizeForEncoding(streamer, PCEncoding); - EmitSymbol(streamer, *frame.Begin, PCEncoding, "FDE initial location"); + EmitFDESymbol(streamer, *frame.Begin, PCEncoding, IsEH, "FDE initial location"); // PC Range const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin, @@ -1364,8 +1368,8 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCStreamer &streamer, // Augmentation Data if (frame.Lsda) - EmitSymbol(streamer, *frame.Lsda, frame.LsdaEncoding, - "Language Specific Data Area"); + EmitFDESymbol(streamer, *frame.Lsda, frame.LsdaEncoding, true, + "Language Specific Data Area"); } // Call Frame Instructions diff --git a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp index 9304dec..b9f3648 100644 --- a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp +++ b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp @@ -65,6 +65,11 @@ X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) { // Exceptions handling ExceptionsType = ExceptionHandling::DwarfCFI; + + // FIXME: this should not depend on the target OS version, but on the ld64 + // version in use. From at least >= ld64-97.17 (Xcode 3.2.6) the abs-ified + // FDE relocs may be used. + DwarfFDESymbolsUseAbsDiff = T.isMacOSX() && !T.isMacOSXVersionLT(10, 6); } X86_64MCAsmInfoDarwin::X86_64MCAsmInfoDarwin(const Triple &Triple)