X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCDwarf.cpp;h=e964032b9d2809f90deb5d0e07324b2c7c10923d;hb=c3d768d729e32c3c9d7a8ec593fc6e3fb4def019;hp=be6731abedd94389f14e1d0bcef62e448338c225;hpb=0d356ec0eebb3fbbb2de0a12743457d44341a047;p=oota-llvm.git diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp index be6731abedd..e964032b9d2 100644 --- a/lib/MC/MCDwarf.cpp +++ b/lib/MC/MCDwarf.cpp @@ -19,6 +19,7 @@ #include "llvm/MC/MCObjectFileInfo.h" #include "llvm/MC/MCObjectStreamer.h" #include "llvm/MC/MCRegisterInfo.h" +#include "llvm/MC/MCSection.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" @@ -26,26 +27,8 @@ #include "llvm/Support/Path.h" #include "llvm/Support/SourceMgr.h" #include "llvm/Support/raw_ostream.h" -using namespace llvm; - -// Given a special op, return the address skip amount (in units of -// DWARF2_LINE_MIN_INSN_LENGTH. -#define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE) - -// The maximum address skip amount that can be encoded with a special op. -#define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255) - -// First special line opcode - leave room for the standard opcodes. -// Note: If you want to change this, you'll have to update the -// "standard_opcode_lengths" table that is emitted in DwarfFileTable::Emit(). -#define DWARF2_LINE_OPCODE_BASE 13 -// Minimum line offset in a special line info. opcode. This value -// was chosen to give a reasonable range of values. -#define DWARF2_LINE_BASE -5 - -// Range of line offsets in a special line info. opcode. -#define DWARF2_LINE_RANGE 14 +using namespace llvm; static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) { unsigned MinInsnLength = Context.getAsmInfo()->getMinInstAlignment(); @@ -63,12 +46,12 @@ static inline uint64_t ScaleAddrDelta(MCContext &Context, uint64_t AddrDelta) { // and if there is information from the last .loc directive that has yet to have // a line entry made for it is made. // -void MCLineEntry::Make(MCObjectStreamer *MCOS, const MCSection *Section) { +void MCLineEntry::Make(MCObjectStreamer *MCOS, MCSection *Section) { if (!MCOS->getContext().getDwarfLocSeen()) return; // Create a symbol at in the current section for use in the line entry. - MCSymbol *LineSym = MCOS->getContext().CreateTempSymbol(); + MCSymbol *LineSym = MCOS->getContext().createTempSymbol(); // Set the value of the symbol to use for the MCLineEntry. MCOS->EmitLabel(LineSym); @@ -79,7 +62,7 @@ void MCLineEntry::Make(MCObjectStreamer *MCOS, const MCSection *Section) { MCLineEntry LineEntry(LineSym, DwarfLoc); // clear DwarfLocSeen saying the current .loc info is now used. - MCOS->getContext().ClearDwarfLocSeen(); + MCOS->getContext().clearDwarfLocSeen(); // Add the line entry to this section's entries. MCOS->getContext() @@ -97,15 +80,15 @@ static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS, int IntVal) { MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None; const MCExpr *Res = - MCSymbolRefExpr::Create(&End, Variant, MCOS.getContext()); + MCSymbolRefExpr::create(&End, Variant, MCOS.getContext()); const MCExpr *RHS = - MCSymbolRefExpr::Create(&Start, Variant, MCOS.getContext()); + MCSymbolRefExpr::create(&Start, Variant, MCOS.getContext()); const MCExpr *Res1 = - MCBinaryExpr::Create(MCBinaryExpr::Sub, Res, RHS, MCOS.getContext()); + MCBinaryExpr::create(MCBinaryExpr::Sub, Res, RHS, MCOS.getContext()); const MCExpr *Res2 = - MCConstantExpr::Create(IntVal, MCOS.getContext()); + MCConstantExpr::create(IntVal, MCOS.getContext()); const MCExpr *Res3 = - MCBinaryExpr::Create(MCBinaryExpr::Sub, Res1, Res2, MCOS.getContext()); + MCBinaryExpr::create(MCBinaryExpr::Sub, Res1, Res2, MCOS.getContext()); return Res3; } @@ -114,7 +97,7 @@ static inline const MCExpr *MakeStartMinusEndExpr(const MCStreamer &MCOS, // in the LineSection. // static inline void -EmitDwarfLineTable(MCObjectStreamer *MCOS, const MCSection *Section, +EmitDwarfLineTable(MCObjectStreamer *MCOS, MCSection *Section, const MCLineSection::MCLineEntryCollection &LineEntries) { unsigned FileNum = 1; unsigned LastLine = 1; @@ -178,34 +161,26 @@ EmitDwarfLineTable(MCObjectStreamer *MCOS, const MCSection *Section, } // Emit a DW_LNE_end_sequence for the end of the section. - // Using the pointer Section create a temporary label at the end of the - // section and use that and the LastLabel to compute the address delta - // and use INT64_MAX as the line delta which is the signal that this is - // actually a DW_LNE_end_sequence. + // Use the section end label to compute the address delta and use INT64_MAX + // as the line delta which is the signal that this is actually a + // DW_LNE_end_sequence. + MCSymbol *SectionEnd = MCOS->endSection(Section); - // Switch to the section to be able to create a symbol at its end. - // TODO: keep track of the last subsection so that this symbol appears in the - // correct place. - MCOS->SwitchSection(Section); + // Switch back the dwarf line section, in case endSection had to switch the + // section. + MCContext &Ctx = MCOS->getContext(); + MCOS->SwitchSection(Ctx.getObjectFileInfo()->getDwarfLineSection()); - MCContext &context = MCOS->getContext(); - // Create a symbol at the end of the section. - MCSymbol *SectionEnd = context.CreateTempSymbol(); - // Set the value of the symbol, as we are at the end of the section. - MCOS->EmitLabel(SectionEnd); - - // Switch back the dwarf line section. - MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfLineSection()); - - const MCAsmInfo *asmInfo = MCOS->getContext().getAsmInfo(); + const MCAsmInfo *AsmInfo = Ctx.getAsmInfo(); MCOS->EmitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, SectionEnd, - asmInfo->getPointerSize()); + AsmInfo->getPointerSize()); } // // This emits the Dwarf file and the line tables. // -void MCDwarfLineTable::Emit(MCObjectStreamer *MCOS) { +void MCDwarfLineTable::Emit(MCObjectStreamer *MCOS, + MCDwarfLineTableParams Params) { MCContext &context = MCOS->getContext(); auto &LineTables = context.getMCDwarfLineTables(); @@ -220,14 +195,17 @@ void MCDwarfLineTable::Emit(MCObjectStreamer *MCOS) { // Handle the rest of the Compile Units. for (const auto &CUIDTablePair : LineTables) - CUIDTablePair.second.EmitCU(MCOS); + CUIDTablePair.second.EmitCU(MCOS, Params); } -void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS) const { - MCOS.EmitLabel(Header.Emit(&MCOS, None).second); +void MCDwarfDwoLineTable::Emit(MCStreamer &MCOS, + MCDwarfLineTableParams Params) const { + MCOS.EmitLabel(Header.Emit(&MCOS, Params, None).second); } -std::pair MCDwarfLineTableHeader::Emit(MCStreamer *MCOS) const { +std::pair +MCDwarfLineTableHeader::Emit(MCStreamer *MCOS, + MCDwarfLineTableParams Params) const { static const char StandardOpcodeLengths[] = { 0, // length of DW_LNS_copy 1, // length of DW_LNS_advance_pc @@ -242,49 +220,67 @@ std::pair MCDwarfLineTableHeader::Emit(MCStreamer *MCOS) 0, // length of DW_LNS_set_epilogue_begin 1 // DW_LNS_set_isa }; - assert(array_lengthof(StandardOpcodeLengths) == (DWARF2_LINE_OPCODE_BASE - 1)); - return Emit(MCOS, StandardOpcodeLengths); + assert(array_lengthof(StandardOpcodeLengths) >= + (Params.DWARF2LineOpcodeBase - 1U)); + return Emit(MCOS, Params, makeArrayRef(StandardOpcodeLengths, + Params.DWARF2LineOpcodeBase - 1)); +} + +static const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) { + MCContext &Context = OS.getContext(); + assert(!isa(Expr)); + if (Context.getAsmInfo()->hasAggressiveSymbolFolding()) + return Expr; + + MCSymbol *ABS = Context.createTempSymbol(); + OS.EmitAssignment(ABS, Expr); + return MCSymbolRefExpr::create(ABS, Context); +} + +static void emitAbsValue(MCStreamer &OS, const MCExpr *Value, unsigned Size) { + const MCExpr *ABS = forceExpAbs(OS, Value); + OS.EmitValue(ABS, Size); } std::pair -MCDwarfLineTableHeader::Emit(MCStreamer *MCOS, +MCDwarfLineTableHeader::Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params, ArrayRef StandardOpcodeLengths) const { - MCContext &context = MCOS->getContext(); // Create a symbol at the beginning of the line table. MCSymbol *LineStartSym = Label; if (!LineStartSym) - LineStartSym = context.CreateTempSymbol(); + LineStartSym = context.createTempSymbol(); // Set the value of the symbol, as we are at the start of the line table. MCOS->EmitLabel(LineStartSym); // Create a symbol for the end of the section (to be set when we get there). - MCSymbol *LineEndSym = context.CreateTempSymbol(); + MCSymbol *LineEndSym = context.createTempSymbol(); // The first 4 bytes is the total length of the information for this // compilation unit (not including these 4 bytes for the length). - MCOS->EmitAbsValue(MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym,4), - 4); + emitAbsValue(*MCOS, + MakeStartMinusEndExpr(*MCOS, *LineStartSym, *LineEndSym, 4), 4); // Next 2 bytes is the Version, which is Dwarf 2. MCOS->EmitIntValue(2, 2); // Create a symbol for the end of the prologue (to be set when we get there). - MCSymbol *ProEndSym = context.CreateTempSymbol(); // Lprologue_end + MCSymbol *ProEndSym = context.createTempSymbol(); // Lprologue_end // Length of the prologue, is the next 4 bytes. Which is the start of the // section to the end of the prologue. Not including the 4 bytes for the // total length, the 2 bytes for the version, and these 4 bytes for the // length of the prologue. - MCOS->EmitAbsValue(MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym, - (4 + 2 + 4)), 4); + emitAbsValue( + *MCOS, + MakeStartMinusEndExpr(*MCOS, *LineStartSym, *ProEndSym, (4 + 2 + 4)), 4); // Parameters of the state machine, are next. MCOS->EmitIntValue(context.getAsmInfo()->getMinInstAlignment(), 1); MCOS->EmitIntValue(DWARF2_LINE_DEFAULT_IS_STMT, 1); - MCOS->EmitIntValue(DWARF2_LINE_BASE, 1); - MCOS->EmitIntValue(DWARF2_LINE_RANGE, 1); + MCOS->EmitIntValue(Params.DWARF2LineBase, 1); + MCOS->EmitIntValue(Params.DWARF2LineRange, 1); MCOS->EmitIntValue(StandardOpcodeLengths.size() + 1, 1); // Standard opcode lengths @@ -319,25 +315,14 @@ MCDwarfLineTableHeader::Emit(MCStreamer *MCOS, return std::make_pair(LineStartSym, LineEndSym); } -void MCDwarfLineTable::EmitCU(MCObjectStreamer *MCOS) const { - MCSymbol *LineEndSym = Header.Emit(MCOS).second; +void MCDwarfLineTable::EmitCU(MCObjectStreamer *MCOS, + MCDwarfLineTableParams Params) const { + MCSymbol *LineEndSym = Header.Emit(MCOS, Params).second; // Put out the line tables. for (const auto &LineSec : MCLineSections.getMCLineEntries()) EmitDwarfLineTable(MCOS, LineSec.first, LineSec.second); - if (MCOS->getContext().getAsmInfo()->getLinkerRequiresNonEmptyDwarfLines() && - MCLineSections.getMCLineEntries().empty()) { - // The darwin9 linker has a bug (see PR8715). For for 32-bit architectures - // it requires: - // total_length >= prologue_length + 10 - // We are 4 bytes short, since we have total_length = 51 and - // prologue_length = 45 - - // The regular end_sequence should be sufficient. - MCDwarfLineAddr::Emit(MCOS, INT64_MAX, 0); - } - // This is the end of the section, so set the value of the symbol at the end // of this section (that was used in a previous expression). MCOS->EmitLabel(LineEndSym); @@ -362,10 +347,12 @@ unsigned MCDwarfLineTableHeader::getFile(StringRef &Directory, FileNumber = SourceIdMap.size() + 1; assert((MCDwarfFiles.empty() || FileNumber == MCDwarfFiles.size()) && "Don't mix autonumbered and explicit numbered line table usage"); - StringMapEntry &Ent = SourceIdMap.GetOrCreateValue( - (Directory + Twine('\0') + FileName).str(), FileNumber); - if (Ent.getValue() != FileNumber) - return Ent.getValue(); + SmallString<256> Buffer; + auto IterBool = SourceIdMap.insert( + std::make_pair((Directory + Twine('\0') + FileName).toStringRef(Buffer), + FileNumber)); + if (!IterBool.second) + return IterBool.first->second; } // Make space for this FileNumber in the MCDwarfFiles vector if needed. MCDwarfFiles.resize(FileNumber + 1); @@ -416,21 +403,31 @@ unsigned MCDwarfLineTableHeader::getFile(StringRef &Directory, } /// Utility function to emit the encoding to a streamer. -void MCDwarfLineAddr::Emit(MCStreamer *MCOS, int64_t LineDelta, - uint64_t AddrDelta) { +void MCDwarfLineAddr::Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params, + int64_t LineDelta, uint64_t AddrDelta) { MCContext &Context = MCOS->getContext(); SmallString<256> Tmp; raw_svector_ostream OS(Tmp); - MCDwarfLineAddr::Encode(Context, LineDelta, AddrDelta, OS); + MCDwarfLineAddr::Encode(Context, Params, LineDelta, AddrDelta, OS); MCOS->EmitBytes(OS.str()); } +/// Given a special op, return the address skip amount (in units of +/// DWARF2_LINE_MIN_INSN_LENGTH). +static uint64_t SpecialAddr(MCDwarfLineTableParams Params, uint64_t op) { + return (op - Params.DWARF2LineOpcodeBase) / Params.DWARF2LineRange; +} + /// Utility function to encode a Dwarf pair of LineDelta and AddrDeltas. -void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta, - uint64_t AddrDelta, raw_ostream &OS) { +void MCDwarfLineAddr::Encode(MCContext &Context, MCDwarfLineTableParams Params, + int64_t LineDelta, uint64_t AddrDelta, + raw_ostream &OS) { uint64_t Temp, Opcode; bool NeedCopy = false; + // The maximum address skip amount that can be encoded with a special op. + uint64_t MaxSpecialAddrDelta = SpecialAddr(Params, 255); + // Scale the address delta by the minimum instruction length. AddrDelta = ScaleAddrDelta(Context, AddrDelta); @@ -438,9 +435,9 @@ void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta, // DW_LNE_end_sequence. We cannot use special opcodes here, since we want the // end_sequence to emit the matrix entry. if (LineDelta == INT64_MAX) { - if (AddrDelta == MAX_SPECIAL_ADDR_DELTA) + if (AddrDelta == MaxSpecialAddrDelta) OS << char(dwarf::DW_LNS_const_add_pc); - else { + else if (AddrDelta) { OS << char(dwarf::DW_LNS_advance_pc); encodeULEB128(AddrDelta, OS); } @@ -451,16 +448,16 @@ void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta, } // Bias the line delta by the base. - Temp = LineDelta - DWARF2_LINE_BASE; + Temp = LineDelta - Params.DWARF2LineBase; // If the line increment is out of range of a special opcode, we must encode // it with DW_LNS_advance_line. - if (Temp >= DWARF2_LINE_RANGE) { + if (Temp >= Params.DWARF2LineRange) { OS << char(dwarf::DW_LNS_advance_line); encodeSLEB128(LineDelta, OS); LineDelta = 0; - Temp = 0 - DWARF2_LINE_BASE; + Temp = 0 - Params.DWARF2LineBase; NeedCopy = true; } @@ -471,19 +468,19 @@ void MCDwarfLineAddr::Encode(MCContext &Context, int64_t LineDelta, } // Bias the opcode by the special opcode base. - Temp += DWARF2_LINE_OPCODE_BASE; + Temp += Params.DWARF2LineOpcodeBase; // Avoid overflow when addr_delta is large. - if (AddrDelta < 256 + MAX_SPECIAL_ADDR_DELTA) { + if (AddrDelta < 256 + MaxSpecialAddrDelta) { // Try using a special opcode. - Opcode = Temp + AddrDelta * DWARF2_LINE_RANGE; + Opcode = Temp + AddrDelta * Params.DWARF2LineRange; if (Opcode <= 255) { OS << char(Opcode); return; } // Try using DW_LNS_const_add_pc followed by special op. - Opcode = Temp + (AddrDelta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE; + Opcode = Temp + (AddrDelta - MaxSpecialAddrDelta) * Params.DWARF2LineRange; if (Opcode <= 255) { OS << char(dwarf::DW_LNS_const_add_pc); OS << char(Opcode); @@ -518,8 +515,13 @@ static void EmitGenDwarfAbbrev(MCStreamer *MCOS) { MCOS->EmitULEB128IntValue(dwarf::DW_TAG_compile_unit); MCOS->EmitIntValue(dwarf::DW_CHILDREN_yes, 1); EmitAbbrev(MCOS, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4); - EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr); - EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr); + if (MCOS->getContext().getGenDwarfSectionSyms().size() > 1 && + MCOS->getContext().getDwarfVersion() >= 3) { + EmitAbbrev(MCOS, dwarf::DW_AT_ranges, dwarf::DW_FORM_data4); + } else { + EmitAbbrev(MCOS, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr); + EmitAbbrev(MCOS, dwarf::DW_AT_high_pc, dwarf::DW_FORM_addr); + } EmitAbbrev(MCOS, dwarf::DW_AT_name, dwarf::DW_FORM_string); if (!context.getCompilationDir().empty()) EmitAbbrev(MCOS, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string); @@ -552,20 +554,14 @@ static void EmitGenDwarfAbbrev(MCStreamer *MCOS) { } // When generating dwarf for assembly source files this emits the data for -// .debug_aranges section. Which contains a header and a table of pairs of -// PointerSize'ed values for the address and size of section(s) with line table -// entries (just the default .text in our case) and a terminating pair of zeros. +// .debug_aranges section. This section contains a header and a table of pairs +// of PointerSize'ed values for the address and size of section(s) with line +// table entries. static void EmitGenDwarfAranges(MCStreamer *MCOS, const MCSymbol *InfoSectionSymbol) { MCContext &context = MCOS->getContext(); - // Create a symbol at the end of the section that we are creating the dwarf - // debugging info to use later in here as part of the expression to calculate - // the size of the section for the table. - MCOS->SwitchSection(context.getGenDwarfSection()); - MCSymbol *SectionEndSym = context.CreateTempSymbol(); - MCOS->EmitLabel(SectionEndSym); - context.setGenDwarfSectionEndSym(SectionEndSym); + auto &Sections = context.getGenDwarfSectionSyms(); MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection()); @@ -583,8 +579,8 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS, Length += Pad; // Add the size of the pair of PointerSize'ed values for the address and size - // of the one default .text section we have in the table. - Length += 2 * AddrSize; + // of each section we have in the table. + Length += 2 * AddrSize * Sections.size(); // And the pair of terminating zeros. Length += 2 * AddrSize; @@ -597,7 +593,8 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS, // The 4 byte offset to the compile unit in the .debug_info from the start // of the .debug_info. if (InfoSectionSymbol) - MCOS->EmitSymbolValue(InfoSectionSymbol, 4); + MCOS->EmitSymbolValue(InfoSectionSymbol, 4, + asmInfo->needsDwarfSectionOffsetDirective()); else MCOS->EmitIntValue(0, 4); // The 1 byte size of an address. @@ -608,14 +605,21 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS, for(int i = 0; i < Pad; i++) MCOS->EmitIntValue(0, 1); - // Now emit the table of pairs of PointerSize'ed values for the section(s) - // address and size, in our case just the one default .text section. - const MCExpr *Addr = MCSymbolRefExpr::Create( - context.getGenDwarfSectionStartSym(), MCSymbolRefExpr::VK_None, context); - const MCExpr *Size = MakeStartMinusEndExpr(*MCOS, - *context.getGenDwarfSectionStartSym(), *SectionEndSym, 0); - MCOS->EmitValue(Addr, AddrSize); - MCOS->EmitAbsValue(Size, AddrSize); + // Now emit the table of pairs of PointerSize'ed values for the section + // addresses and sizes. + for (MCSection *Sec : Sections) { + const MCSymbol *StartSymbol = Sec->getBeginSymbol(); + MCSymbol *EndSymbol = Sec->getEndSymbol(context); + assert(StartSymbol && "StartSymbol must not be NULL"); + assert(EndSymbol && "EndSymbol must not be NULL"); + + const MCExpr *Addr = MCSymbolRefExpr::create( + StartSymbol, MCSymbolRefExpr::VK_None, context); + const MCExpr *Size = MakeStartMinusEndExpr(*MCOS, + *StartSymbol, *EndSymbol, 0); + MCOS->EmitValue(Addr, AddrSize); + emitAbsValue(*MCOS, Size, AddrSize); + } // And finally the pair of terminating zeros. MCOS->EmitIntValue(0, AddrSize); @@ -627,34 +631,36 @@ static void EmitGenDwarfAranges(MCStreamer *MCOS, // DIE and a list of label DIEs. static void EmitGenDwarfInfo(MCStreamer *MCOS, const MCSymbol *AbbrevSectionSymbol, - const MCSymbol *LineSectionSymbol) { + const MCSymbol *LineSectionSymbol, + const MCSymbol *RangesSectionSymbol) { MCContext &context = MCOS->getContext(); MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection()); // Create a symbol at the start and end of this section used in here for the // expression to calculate the length in the header. - MCSymbol *InfoStart = context.CreateTempSymbol(); + MCSymbol *InfoStart = context.createTempSymbol(); MCOS->EmitLabel(InfoStart); - MCSymbol *InfoEnd = context.CreateTempSymbol(); + MCSymbol *InfoEnd = context.createTempSymbol(); // First part: the header. // The 4 byte total length of the information for this compilation unit, not // including these 4 bytes. const MCExpr *Length = MakeStartMinusEndExpr(*MCOS, *InfoStart, *InfoEnd, 4); - MCOS->EmitAbsValue(Length, 4); + emitAbsValue(*MCOS, Length, 4); // The 2 byte DWARF version. MCOS->EmitIntValue(context.getDwarfVersion(), 2); + const MCAsmInfo &AsmInfo = *context.getAsmInfo(); // The 4 byte offset to the debug abbrevs from the start of the .debug_abbrev, // it is at the start of that section so this is zero. - if (AbbrevSectionSymbol) { - MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4); - } else { + if (AbbrevSectionSymbol == nullptr) MCOS->EmitIntValue(0, 4); - } + else + MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4, + AsmInfo.needsDwarfSectionOffsetDirective()); const MCAsmInfo *asmInfo = context.getAsmInfo(); int AddrSize = asmInfo->getPointerSize(); @@ -668,21 +674,43 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS, // DW_AT_stmt_list, a 4 byte offset from the start of the .debug_line section, // which is at the start of that section so this is zero. - if (LineSectionSymbol) { - MCOS->EmitSymbolValue(LineSectionSymbol, 4); - } else { + if (LineSectionSymbol) + MCOS->EmitSymbolValue(LineSectionSymbol, 4, + AsmInfo.needsDwarfSectionOffsetDirective()); + else MCOS->EmitIntValue(0, 4); - } - // AT_low_pc, the first address of the default .text section. - const MCExpr *Start = MCSymbolRefExpr::Create( - context.getGenDwarfSectionStartSym(), MCSymbolRefExpr::VK_None, context); - MCOS->EmitValue(Start, AddrSize); + if (RangesSectionSymbol) { + // There are multiple sections containing code, so we must use the + // .debug_ranges sections. - // AT_high_pc, the last address of the default .text section. - const MCExpr *End = MCSymbolRefExpr::Create( - context.getGenDwarfSectionEndSym(), MCSymbolRefExpr::VK_None, context); - MCOS->EmitValue(End, AddrSize); + // AT_ranges, the 4 byte offset from the start of the .debug_ranges section + // to the address range list for this compilation unit. + MCOS->EmitSymbolValue(RangesSectionSymbol, 4); + } else { + // If we only have one non-empty code section, we can use the simpler + // AT_low_pc and AT_high_pc attributes. + + // Find the first (and only) non-empty text section + auto &Sections = context.getGenDwarfSectionSyms(); + const auto TextSection = Sections.begin(); + assert(TextSection != Sections.end() && "No text section found"); + + MCSymbol *StartSymbol = (*TextSection)->getBeginSymbol(); + MCSymbol *EndSymbol = (*TextSection)->getEndSymbol(context); + assert(StartSymbol && "StartSymbol must not be NULL"); + assert(EndSymbol && "EndSymbol must not be NULL"); + + // AT_low_pc, the first address of the default .text section. + const MCExpr *Start = MCSymbolRefExpr::create( + StartSymbol, MCSymbolRefExpr::VK_None, context); + MCOS->EmitValue(Start, AddrSize); + + // AT_high_pc, the last address of the default .text section. + const MCExpr *End = MCSymbolRefExpr::create( + EndSymbol, MCSymbolRefExpr::VK_None, context); + MCOS->EmitValue(End, AddrSize); + } // AT_name, the name of the source file. Reconstruct from the first directory // and file table entries. @@ -711,14 +739,10 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS, // AT_producer, the version of the assembler tool. StringRef DwarfDebugProducer = context.getDwarfDebugProducer(); - if (!DwarfDebugProducer.empty()){ + if (!DwarfDebugProducer.empty()) MCOS->EmitBytes(DwarfDebugProducer); - } - else { - MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM ")); - MCOS->EmitBytes(StringRef(PACKAGE_VERSION)); - MCOS->EmitBytes(StringRef(")")); - } + else + MCOS->EmitBytes(StringRef("llvm-mc (based on LLVM " PACKAGE_VERSION ")")); MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string. // AT_language, a 4 byte value. We use DW_LANG_Mips_Assembler as the dwarf2 @@ -745,7 +769,7 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS, MCOS->EmitIntValue(Entry.getLineNumber(), 4); // AT_low_pc, start address of the label. - const MCExpr *AT_low_pc = MCSymbolRefExpr::Create(Entry.getLabel(), + const MCExpr *AT_low_pc = MCSymbolRefExpr::create(Entry.getLabel(), MCSymbolRefExpr::VK_None, context); MCOS->EmitValue(AT_low_pc, AddrSize); @@ -766,13 +790,50 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS, MCOS->EmitLabel(InfoEnd); } +// When generating dwarf for assembly source files this emits the data for +// .debug_ranges section. We only emit one range list, which spans all of the +// executable sections of this file. +static void EmitGenDwarfRanges(MCStreamer *MCOS) { + MCContext &context = MCOS->getContext(); + auto &Sections = context.getGenDwarfSectionSyms(); + + const MCAsmInfo *AsmInfo = context.getAsmInfo(); + int AddrSize = AsmInfo->getPointerSize(); + + MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection()); + + for (MCSection *Sec : Sections) { + const MCSymbol *StartSymbol = Sec->getBeginSymbol(); + MCSymbol *EndSymbol = Sec->getEndSymbol(context); + assert(StartSymbol && "StartSymbol must not be NULL"); + assert(EndSymbol && "EndSymbol must not be NULL"); + + // Emit a base address selection entry for the start of this section + const MCExpr *SectionStartAddr = MCSymbolRefExpr::create( + StartSymbol, MCSymbolRefExpr::VK_None, context); + MCOS->EmitFill(AddrSize, 0xFF); + MCOS->EmitValue(SectionStartAddr, AddrSize); + + // Emit a range list entry spanning this section + const MCExpr *SectionSize = MakeStartMinusEndExpr(*MCOS, + *StartSymbol, *EndSymbol, 0); + MCOS->EmitIntValue(0, AddrSize); + emitAbsValue(*MCOS, SectionSize, AddrSize); + } + + // Emit end of list entry + MCOS->EmitIntValue(0, AddrSize); + MCOS->EmitIntValue(0, AddrSize); +} + // // When generating dwarf for assembly source files this emits the Dwarf // sections. // void MCGenDwarfInfo::Emit(MCStreamer *MCOS) { - // Create the dwarf sections in this order (.debug_line already created). MCContext &context = MCOS->getContext(); + + // Create the dwarf sections in this order (.debug_line already created). const MCAsmInfo *AsmInfo = context.getAsmInfo(); bool CreateDwarfSectionSymbols = AsmInfo->doesDwarfUseRelocationsAcrossSections(); @@ -781,30 +842,57 @@ void MCGenDwarfInfo::Emit(MCStreamer *MCOS) { LineSectionSymbol = MCOS->getDwarfLineTableSymbol(0); MCSymbol *AbbrevSectionSymbol = nullptr; MCSymbol *InfoSectionSymbol = nullptr; + MCSymbol *RangesSectionSymbol = nullptr; + + // Create end symbols for each section, and remove empty sections + MCOS->getContext().finalizeDwarfSections(*MCOS); + + // If there are no sections to generate debug info for, we don't need + // to do anything + if (MCOS->getContext().getGenDwarfSectionSyms().empty()) + return; + + // We only use the .debug_ranges section if we have multiple code sections, + // and we are emitting a DWARF version which supports it. + const bool UseRangesSection = + MCOS->getContext().getGenDwarfSectionSyms().size() > 1 && + MCOS->getContext().getDwarfVersion() >= 3; + CreateDwarfSectionSymbols |= UseRangesSection; + MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfInfoSection()); if (CreateDwarfSectionSymbols) { - InfoSectionSymbol = context.CreateTempSymbol(); + InfoSectionSymbol = context.createTempSymbol(); MCOS->EmitLabel(InfoSectionSymbol); } MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfAbbrevSection()); if (CreateDwarfSectionSymbols) { - AbbrevSectionSymbol = context.CreateTempSymbol(); + AbbrevSectionSymbol = context.createTempSymbol(); MCOS->EmitLabel(AbbrevSectionSymbol); } - MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection()); + if (UseRangesSection) { + MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfRangesSection()); + if (CreateDwarfSectionSymbols) { + RangesSectionSymbol = context.createTempSymbol(); + MCOS->EmitLabel(RangesSectionSymbol); + } + } - // If there are no line table entries then do not emit any section contents. - if (!context.hasMCLineSections()) - return; + assert((RangesSectionSymbol != NULL) || !UseRangesSection); + + MCOS->SwitchSection(context.getObjectFileInfo()->getDwarfARangesSection()); // Output the data for .debug_aranges section. EmitGenDwarfAranges(MCOS, InfoSectionSymbol); + if (UseRangesSection) + EmitGenDwarfRanges(MCOS); + // Output the data for .debug_abbrev section. EmitGenDwarfAbbrev(MCOS); // Output the data for .debug_info section. - EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol); + EmitGenDwarfInfo(MCOS, AbbrevSectionSymbol, LineSectionSymbol, + RangesSectionSymbol); } // @@ -815,12 +903,13 @@ void MCGenDwarfInfo::Emit(MCStreamer *MCOS) { // void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS, SourceMgr &SrcMgr, SMLoc &Loc) { - // We won't create dwarf labels for temporary symbols or symbols not in - // the default text. + // We won't create dwarf labels for temporary symbols. if (Symbol->isTemporary()) return; MCContext &context = MCOS->getContext(); - if (context.getGenDwarfSection() != MCOS->getCurrentSection().first) + // We won't create dwarf labels for symbols in sections that we are not + // generating debug info for. + if (!context.getGenDwarfSectionSyms().count(MCOS->getCurrentSection().first)) return; // The dwarf label's name does not have the symbol name's leading @@ -834,14 +923,14 @@ void MCGenDwarfLabelEntry::Make(MCSymbol *Symbol, MCStreamer *MCOS, // Finding the line number is the expensive part which is why we just don't // pass it in as for some symbols we won't create a dwarf label. - int CurBuffer = SrcMgr.FindBufferContainingLoc(Loc); + unsigned CurBuffer = SrcMgr.FindBufferContainingLoc(Loc); unsigned LineNumber = SrcMgr.FindLineNumber(Loc, CurBuffer); // We create a temporary symbol for use for the AT_high_pc and AT_low_pc // values so that they don't have things like an ARM thumb bit from the // original symbol. So when used they won't get a low bit set after // relocation. - MCSymbol *Label = context.CreateTempSymbol(); + MCSymbol *Label = context.createTempSymbol(); MCOS->EmitLabel(Label); // Create and entry for the info and add it to the other entries. @@ -880,18 +969,16 @@ static unsigned getSizeForEncoding(MCStreamer &streamer, } } -static void EmitFDESymbol(MCStreamer &streamer, const MCSymbol &symbol, - unsigned symbolEncoding, bool isEH, - const char *comment = nullptr) { +static void emitFDESymbol(MCObjectStreamer &streamer, const MCSymbol &symbol, + unsigned symbolEncoding, bool isEH) { MCContext &context = streamer.getContext(); const MCAsmInfo *asmInfo = context.getAsmInfo(); const MCExpr *v = asmInfo->getExprForFDESymbol(&symbol, symbolEncoding, streamer); unsigned size = getSizeForEncoding(streamer, symbolEncoding); - if (streamer.isVerboseAsm() && comment) streamer.AddComment(comment); if (asmInfo->doDwarfFDESymbolsUseAbsDiff() && isEH) - streamer.EmitAbsValue(v, size); + emitAbsValue(streamer, v, size); else streamer.EmitValue(v, size); } @@ -910,17 +997,18 @@ static void EmitPersonality(MCStreamer &streamer, const MCSymbol &symbol, namespace { class FrameEmitterImpl { int CFAOffset; - int CIENum; + int InitialCFAOffset; bool IsEH; const MCSymbol *SectionStart; public: FrameEmitterImpl(bool isEH) - : CFAOffset(0), CIENum(0), IsEH(isEH), SectionStart(nullptr) {} + : CFAOffset(0), InitialCFAOffset(0), IsEH(isEH), SectionStart(nullptr) { + } void setSectionStart(const MCSymbol *Label) { SectionStart = Label; } - /// EmitCompactUnwind - Emit the unwind information in a compact way. - void EmitCompactUnwind(MCStreamer &streamer, + /// Emit the unwind information in a compact way. + void EmitCompactUnwind(MCObjectStreamer &streamer, const MCDwarfFrameInfo &frame); const MCSymbol &EmitCIE(MCObjectStreamer &streamer, @@ -942,64 +1030,22 @@ namespace { } // end anonymous namespace -static void EmitEncodingByte(MCStreamer &Streamer, unsigned Encoding, - StringRef Prefix) { - if (Streamer.isVerboseAsm()) { - const char *EncStr; - switch (Encoding) { - default: EncStr = ""; break; - case dwarf::DW_EH_PE_absptr: EncStr = "absptr"; break; - case dwarf::DW_EH_PE_omit: EncStr = "omit"; break; - case dwarf::DW_EH_PE_pcrel: EncStr = "pcrel"; break; - case dwarf::DW_EH_PE_udata4: EncStr = "udata4"; break; - case dwarf::DW_EH_PE_udata8: EncStr = "udata8"; break; - case dwarf::DW_EH_PE_sdata4: EncStr = "sdata4"; break; - case dwarf::DW_EH_PE_sdata8: EncStr = "sdata8"; break; - case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4: - EncStr = "pcrel udata4"; - break; - case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4: - EncStr = "pcrel sdata4"; - break; - case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8: - EncStr = "pcrel udata8"; - break; - case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8: - EncStr = "screl sdata8"; - break; - case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_udata4: - EncStr = "indirect pcrel udata4"; - break; - case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_sdata4: - EncStr = "indirect pcrel sdata4"; - break; - case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_udata8: - EncStr = "indirect pcrel udata8"; - break; - case dwarf::DW_EH_PE_indirect |dwarf::DW_EH_PE_pcrel|dwarf::DW_EH_PE_sdata8: - EncStr = "indirect pcrel sdata8"; - break; - } - - Streamer.AddComment(Twine(Prefix) + " = " + EncStr); - } - +static void emitEncodingByte(MCObjectStreamer &Streamer, unsigned Encoding) { Streamer.EmitIntValue(Encoding, 1); } void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer, const MCCFIInstruction &Instr) { int dataAlignmentFactor = getDataAlignmentFactor(Streamer); - bool VerboseAsm = Streamer.isVerboseAsm(); + auto *MRI = Streamer.getContext().getRegisterInfo(); switch (Instr.getOperation()) { case MCCFIInstruction::OpRegister: { unsigned Reg1 = Instr.getRegister(); unsigned Reg2 = Instr.getRegister2(); - if (VerboseAsm) { - Streamer.AddComment("DW_CFA_register"); - Streamer.AddComment(Twine("Reg1 ") + Twine(Reg1)); - Streamer.AddComment(Twine("Reg2 ") + Twine(Reg2)); + if (!IsEH) { + Reg1 = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg1, true), false); + Reg2 = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg2, true), false); } Streamer.EmitIntValue(dwarf::DW_CFA_register, 1); Streamer.EmitULEB128IntValue(Reg1); @@ -1012,10 +1058,6 @@ void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer, } case MCCFIInstruction::OpUndefined: { unsigned Reg = Instr.getRegister(); - if (VerboseAsm) { - Streamer.AddComment("DW_CFA_undefined"); - Streamer.AddComment(Twine("Reg ") + Twine(Reg)); - } Streamer.EmitIntValue(dwarf::DW_CFA_undefined, 1); Streamer.EmitULEB128IntValue(Reg); return; @@ -1025,8 +1067,6 @@ void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer, const bool IsRelative = Instr.getOperation() == MCCFIInstruction::OpAdjustCfaOffset; - if (VerboseAsm) - Streamer.AddComment("DW_CFA_def_cfa_offset"); Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1); if (IsRelative) @@ -1034,38 +1074,28 @@ void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer, else CFAOffset = -Instr.getOffset(); - if (VerboseAsm) - Streamer.AddComment(Twine("Offset " + Twine(CFAOffset))); Streamer.EmitULEB128IntValue(CFAOffset); return; } case MCCFIInstruction::OpDefCfa: { - if (VerboseAsm) - Streamer.AddComment("DW_CFA_def_cfa"); + unsigned Reg = Instr.getRegister(); + if (!IsEH) + Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false); Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1); - - if (VerboseAsm) - Streamer.AddComment(Twine("Reg ") + Twine(Instr.getRegister())); - Streamer.EmitULEB128IntValue(Instr.getRegister()); - + Streamer.EmitULEB128IntValue(Reg); CFAOffset = -Instr.getOffset(); - - if (VerboseAsm) - Streamer.AddComment(Twine("Offset " + Twine(CFAOffset))); Streamer.EmitULEB128IntValue(CFAOffset); return; } case MCCFIInstruction::OpDefCfaRegister: { - if (VerboseAsm) - Streamer.AddComment("DW_CFA_def_cfa_register"); + unsigned Reg = Instr.getRegister(); + if (!IsEH) + Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false); Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1); - - if (VerboseAsm) - Streamer.AddComment(Twine("Reg ") + Twine(Instr.getRegister())); - Streamer.EmitULEB128IntValue(Instr.getRegister()); + Streamer.EmitULEB128IntValue(Reg); return; } @@ -1076,69 +1106,60 @@ void FrameEmitterImpl::EmitCFIInstruction(MCObjectStreamer &Streamer, Instr.getOperation() == MCCFIInstruction::OpRelOffset; unsigned Reg = Instr.getRegister(); + if (!IsEH) + Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false); + int Offset = Instr.getOffset(); if (IsRelative) Offset -= CFAOffset; Offset = Offset / dataAlignmentFactor; if (Offset < 0) { - if (VerboseAsm) Streamer.AddComment("DW_CFA_offset_extended_sf"); Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1); - if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg)); Streamer.EmitULEB128IntValue(Reg); - if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset)); Streamer.EmitSLEB128IntValue(Offset); } else if (Reg < 64) { - if (VerboseAsm) Streamer.AddComment(Twine("DW_CFA_offset + Reg(") + - Twine(Reg) + ")"); Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1); - if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset)); Streamer.EmitULEB128IntValue(Offset); } else { - if (VerboseAsm) Streamer.AddComment("DW_CFA_offset_extended"); Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended, 1); - if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg)); Streamer.EmitULEB128IntValue(Reg); - if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset)); Streamer.EmitULEB128IntValue(Offset); } return; } case MCCFIInstruction::OpRememberState: - if (VerboseAsm) Streamer.AddComment("DW_CFA_remember_state"); Streamer.EmitIntValue(dwarf::DW_CFA_remember_state, 1); return; case MCCFIInstruction::OpRestoreState: - if (VerboseAsm) Streamer.AddComment("DW_CFA_restore_state"); Streamer.EmitIntValue(dwarf::DW_CFA_restore_state, 1); return; case MCCFIInstruction::OpSameValue: { unsigned Reg = Instr.getRegister(); - if (VerboseAsm) Streamer.AddComment("DW_CFA_same_value"); Streamer.EmitIntValue(dwarf::DW_CFA_same_value, 1); - if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg)); Streamer.EmitULEB128IntValue(Reg); return; } case MCCFIInstruction::OpRestore: { unsigned Reg = Instr.getRegister(); - if (VerboseAsm) { - Streamer.AddComment("DW_CFA_restore"); - Streamer.AddComment(Twine("Reg ") + Twine(Reg)); - } + if (!IsEH) + Reg = MRI->getDwarfRegNum(MRI->getLLVMRegNum(Reg, true), false); Streamer.EmitIntValue(dwarf::DW_CFA_restore | Reg, 1); return; } + case MCCFIInstruction::OpGnuArgsSize: { + Streamer.EmitIntValue(dwarf::DW_CFA_GNU_args_size, 1); + Streamer.EmitULEB128IntValue(Instr.getOffset()); + return; + } case MCCFIInstruction::OpEscape: - if (VerboseAsm) Streamer.AddComment("Escape bytes"); Streamer.EmitBytes(Instr.getValues()); return; } llvm_unreachable("Unhandled case in switch"); } -/// EmitFrameMoves - Emit frame instructions to describe the layout of the -/// frame. +/// Emit frame instructions to describe the layout of the frame. void FrameEmitterImpl::EmitCFIInstructions(MCObjectStreamer &streamer, ArrayRef Instrs, MCSymbol *BaseLabel) { @@ -1152,7 +1173,6 @@ void FrameEmitterImpl::EmitCFIInstructions(MCObjectStreamer &streamer, if (BaseLabel && Label) { MCSymbol *ThisSym = Label; if (ThisSym != BaseLabel) { - if (streamer.isVerboseAsm()) streamer.AddComment("DW_CFA_advance_loc4"); streamer.EmitDwarfAdvanceFrameAddr(BaseLabel, ThisSym); BaseLabel = ThisSym; } @@ -1162,12 +1182,11 @@ void FrameEmitterImpl::EmitCFIInstructions(MCObjectStreamer &streamer, } } -/// EmitCompactUnwind - Emit the unwind information in a compact way. -void FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer, +/// Emit the unwind information in a compact way. +void FrameEmitterImpl::EmitCompactUnwind(MCObjectStreamer &Streamer, const MCDwarfFrameInfo &Frame) { MCContext &Context = Streamer.getContext(); const MCObjectFileInfo *MOFI = Context.getObjectFileInfo(); - bool VerboseAsm = Streamer.isVerboseAsm(); // range-start range-length compact-unwind-enc personality-func lsda // _foo LfooEnd-_foo 0x00000023 0 0 @@ -1202,24 +1221,19 @@ void FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer, // Range Start unsigned FDEEncoding = MOFI->getFDEEncoding(); unsigned Size = getSizeForEncoding(Streamer, FDEEncoding); - if (VerboseAsm) Streamer.AddComment("Range Start"); - Streamer.EmitSymbolValue(Frame.Function, Size); + Streamer.EmitSymbolValue(Frame.Begin, Size); // Range Length const MCExpr *Range = MakeStartMinusEndExpr(Streamer, *Frame.Begin, *Frame.End, 0); - if (VerboseAsm) Streamer.AddComment("Range Length"); - Streamer.EmitAbsValue(Range, 4); + emitAbsValue(Streamer, Range, 4); // Compact Encoding Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_udata4); - if (VerboseAsm) Streamer.AddComment("Compact Unwind Encoding: 0x" + - Twine::utohexstr(Encoding)); Streamer.EmitIntValue(Encoding, Size); // Personality Function Size = getSizeForEncoding(Streamer, dwarf::DW_EH_PE_absptr); - if (VerboseAsm) Streamer.AddComment("Personality Function"); if (!DwarfEHFrameOnly && Frame.Personality) Streamer.EmitSymbolValue(Frame.Personality, Size); else @@ -1227,13 +1241,26 @@ void FrameEmitterImpl::EmitCompactUnwind(MCStreamer &Streamer, // LSDA Size = getSizeForEncoding(Streamer, Frame.LsdaEncoding); - if (VerboseAsm) Streamer.AddComment("LSDA"); if (!DwarfEHFrameOnly && Frame.Lsda) Streamer.EmitSymbolValue(Frame.Lsda, Size); else Streamer.EmitIntValue(0, Size); // No LSDA } +static unsigned getCIEVersion(bool IsEH, unsigned DwarfVersion) { + if (IsEH) + return 1; + switch (DwarfVersion) { + case 2: + return 1; + case 3: + return 3; + case 4: + return 4; + } + llvm_unreachable("Unknown version"); +} + const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, const MCSymbol *personality, unsigned personalityEncoding, @@ -1244,38 +1271,28 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, MCContext &context = streamer.getContext(); const MCRegisterInfo *MRI = context.getRegisterInfo(); const MCObjectFileInfo *MOFI = context.getObjectFileInfo(); - bool verboseAsm = streamer.isVerboseAsm(); - - MCSymbol *sectionStart; - if (MOFI->isFunctionEHFrameSymbolPrivate() || !IsEH) - sectionStart = context.CreateTempSymbol(); - else - sectionStart = context.GetOrCreateSymbol(Twine("EH_frame") + Twine(CIENum)); + MCSymbol *sectionStart = context.createTempSymbol(); streamer.EmitLabel(sectionStart); - CIENum++; - MCSymbol *sectionEnd = context.CreateTempSymbol(); + MCSymbol *sectionEnd = context.createTempSymbol(); // Length const MCExpr *Length = MakeStartMinusEndExpr(streamer, *sectionStart, *sectionEnd, 4); - if (verboseAsm) streamer.AddComment("CIE Length"); - streamer.EmitAbsValue(Length, 4); + emitAbsValue(streamer, Length, 4); // CIE ID unsigned CIE_ID = IsEH ? 0 : -1; - if (verboseAsm) streamer.AddComment("CIE ID Tag"); streamer.EmitIntValue(CIE_ID, 4); // Version - if (verboseAsm) streamer.AddComment("DW_CIE_VERSION"); - streamer.EmitIntValue(dwarf::DW_CIE_VERSION, 1); + uint8_t CIEVersion = getCIEVersion(IsEH, context.getDwarfVersion()); + streamer.EmitIntValue(CIEVersion, 1); // Augmentation String SmallString<8> Augmentation; if (IsEH) { - if (verboseAsm) streamer.AddComment("CIE Augmentation"); Augmentation += "z"; if (personality) Augmentation += "P"; @@ -1284,21 +1301,33 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, Augmentation += "R"; if (IsSignalFrame) Augmentation += "S"; - streamer.EmitBytes(Augmentation.str()); + streamer.EmitBytes(Augmentation); } streamer.EmitIntValue(0, 1); + if (CIEVersion >= 4) { + // Address Size + streamer.EmitIntValue(context.getAsmInfo()->getPointerSize(), 1); + + // Segment Descriptor Size + streamer.EmitIntValue(0, 1); + } + // Code Alignment Factor - if (verboseAsm) streamer.AddComment("CIE Code Alignment Factor"); streamer.EmitULEB128IntValue(context.getAsmInfo()->getMinInstAlignment()); // Data Alignment Factor - if (verboseAsm) streamer.AddComment("CIE Data Alignment Factor"); streamer.EmitSLEB128IntValue(getDataAlignmentFactor(streamer)); // Return Address Register - if (verboseAsm) streamer.AddComment("CIE Return Address Column"); - streamer.EmitULEB128IntValue(MRI->getDwarfRegNum(MRI->getRARegister(), true)); + if (CIEVersion == 1) { + assert(MRI->getRARegister() <= 255 && + "DWARF 2 encodes return_address_register in one byte"); + streamer.EmitIntValue(MRI->getDwarfRegNum(MRI->getRARegister(), IsEH), 1); + } else { + streamer.EmitULEB128IntValue( + MRI->getDwarfRegNum(MRI->getRARegister(), IsEH)); + } // Augmentation Data Length (optional) @@ -1315,24 +1344,21 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, // Encoding of the FDE pointers augmentationLength += 1; - if (verboseAsm) streamer.AddComment("Augmentation Size"); streamer.EmitULEB128IntValue(augmentationLength); // Augmentation Data (optional) if (personality) { // Personality Encoding - EmitEncodingByte(streamer, personalityEncoding, - "Personality Encoding"); + emitEncodingByte(streamer, personalityEncoding); // Personality - if (verboseAsm) streamer.AddComment("Personality"); EmitPersonality(streamer, *personality, personalityEncoding); } if (lsda) - EmitEncodingByte(streamer, lsdaEncoding, "LSDA Encoding"); + emitEncodingByte(streamer, lsdaEncoding); // Encoding of the FDE pointers - EmitEncodingByte(streamer, MOFI->getFDEEncoding(), "FDE Encoding"); + emitEncodingByte(streamer, MOFI->getFDEEncoding()); } // Initial Instructions @@ -1344,6 +1370,8 @@ const MCSymbol &FrameEmitterImpl::EmitCIE(MCObjectStreamer &streamer, EmitCFIInstructions(streamer, Instructions, nullptr); } + InitialCFAOffset = CFAOffset; + // Padding streamer.EmitValueToAlignment(IsEH ? 4 : MAI->getPointerSize()); @@ -1355,22 +1383,15 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCObjectStreamer &streamer, const MCSymbol &cieStart, const MCDwarfFrameInfo &frame) { MCContext &context = streamer.getContext(); - MCSymbol *fdeStart = context.CreateTempSymbol(); - MCSymbol *fdeEnd = context.CreateTempSymbol(); + MCSymbol *fdeStart = context.createTempSymbol(); + MCSymbol *fdeEnd = context.createTempSymbol(); const MCObjectFileInfo *MOFI = context.getObjectFileInfo(); - bool verboseAsm = streamer.isVerboseAsm(); - if (IsEH && frame.Function && !MOFI->isFunctionEHFrameSymbolPrivate()) { - MCSymbol *EHSym = - context.GetOrCreateSymbol(frame.Function->getName() + Twine(".eh")); - streamer.EmitEHSymAttributes(frame.Function, EHSym); - streamer.EmitLabel(EHSym); - } + CFAOffset = InitialCFAOffset; // Length const MCExpr *Length = MakeStartMinusEndExpr(streamer, *fdeStart, *fdeEnd, 0); - if (verboseAsm) streamer.AddComment("FDE Length"); - streamer.EmitAbsValue(Length, 4); + emitAbsValue(streamer, Length, 4); streamer.EmitLabel(fdeStart); @@ -1379,12 +1400,11 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCObjectStreamer &streamer, if (IsEH) { const MCExpr *offset = MakeStartMinusEndExpr(streamer, cieStart, *fdeStart, 0); - if (verboseAsm) streamer.AddComment("FDE CIE Offset"); - streamer.EmitAbsValue(offset, 4); + emitAbsValue(streamer, offset, 4); } else if (!asmInfo->doesDwarfUseRelocationsAcrossSections()) { const MCExpr *offset = MakeStartMinusEndExpr(streamer, *SectionStart, cieStart, 0); - streamer.EmitAbsValue(offset, 4); + emitAbsValue(streamer, offset, 4); } else { streamer.EmitSymbolValue(&cieStart, 4); } @@ -1393,13 +1413,12 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCObjectStreamer &streamer, unsigned PCEncoding = IsEH ? MOFI->getFDEEncoding() : (unsigned)dwarf::DW_EH_PE_absptr; unsigned PCSize = getSizeForEncoding(streamer, PCEncoding); - EmitFDESymbol(streamer, *frame.Begin, PCEncoding, IsEH, "FDE initial location"); + emitFDESymbol(streamer, *frame.Begin, PCEncoding, IsEH); // PC Range const MCExpr *Range = MakeStartMinusEndExpr(streamer, *frame.Begin, *frame.End, 0); - if (verboseAsm) streamer.AddComment("FDE address range"); - streamer.EmitAbsValue(Range, PCSize); + emitAbsValue(streamer, Range, PCSize); if (IsEH) { // Augmentation Data Length @@ -1408,13 +1427,11 @@ MCSymbol *FrameEmitterImpl::EmitFDE(MCObjectStreamer &streamer, if (frame.Lsda) augmentationLength += getSizeForEncoding(streamer, frame.LsdaEncoding); - if (verboseAsm) streamer.AddComment("Augmentation size"); streamer.EmitULEB128IntValue(augmentationLength); // Augmentation Data if (frame.Lsda) - EmitFDESymbol(streamer, *frame.Lsda, frame.LsdaEncoding, true, - "Language Specific Data Area"); + emitFDESymbol(streamer, *frame.Lsda, frame.LsdaEncoding, true); } // Call Frame Instructions @@ -1435,19 +1452,18 @@ namespace { return CIEKey(nullptr, -1, 0, false, false); } - CIEKey(const MCSymbol* Personality_, unsigned PersonalityEncoding_, - unsigned LsdaEncoding_, bool IsSignalFrame_, bool IsSimple_) : - Personality(Personality_), PersonalityEncoding(PersonalityEncoding_), - LsdaEncoding(LsdaEncoding_), IsSignalFrame(IsSignalFrame_), - IsSimple(IsSimple_) { - } - const MCSymbol* Personality; + CIEKey(const MCSymbol *Personality_, unsigned PersonalityEncoding_, + unsigned LsdaEncoding_, bool IsSignalFrame_, bool IsSimple_) + : Personality(Personality_), PersonalityEncoding(PersonalityEncoding_), + LsdaEncoding(LsdaEncoding_), IsSignalFrame(IsSignalFrame_), + IsSimple(IsSimple_) {} + const MCSymbol *Personality; unsigned PersonalityEncoding; unsigned LsdaEncoding; bool IsSignalFrame; bool IsSimple; }; -} +} // anonymous namespace namespace llvm { template <> @@ -1474,7 +1490,7 @@ namespace llvm { LHS.IsSimple == RHS.IsSimple; } }; -} +} // namespace llvm void MCDwarfFrameEmitter::Emit(MCObjectStreamer &Streamer, MCAsmBackend *MAB, bool IsEH) { @@ -1483,7 +1499,7 @@ void MCDwarfFrameEmitter::Emit(MCObjectStreamer &Streamer, MCAsmBackend *MAB, MCContext &Context = Streamer.getContext(); const MCObjectFileInfo *MOFI = Context.getObjectFileInfo(); FrameEmitterImpl Emitter(IsEH); - ArrayRef FrameArray = Streamer.getFrameInfos(); + ArrayRef FrameArray = Streamer.getDwarfFrameInfos(); // Emit the compact unwind info if available. bool NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame(); @@ -1506,17 +1522,17 @@ void MCDwarfFrameEmitter::Emit(MCObjectStreamer &Streamer, MCAsmBackend *MAB, if (!NeedsEHFrameSection) return; - const MCSection &Section = - IsEH ? *const_cast(MOFI)->getEHFrameSection() : - *MOFI->getDwarfFrameSection(); + MCSection &Section = + IsEH ? *const_cast(MOFI)->getEHFrameSection() + : *MOFI->getDwarfFrameSection(); Streamer.SwitchSection(&Section); - MCSymbol *SectionStart = Context.CreateTempSymbol(); + MCSymbol *SectionStart = Context.createTempSymbol(); Streamer.EmitLabel(SectionStart); Emitter.setSectionStart(SectionStart); MCSymbol *FDEEnd = nullptr; - DenseMap CIEStarts; + DenseMap CIEStarts; const MCSymbol *DummyDebugKey = nullptr; NeedsEHFrameSection = !MOFI->getSupportsCompactUnwindWithoutEHFrame(); @@ -1576,18 +1592,17 @@ void MCDwarfFrameEmitter::EncodeAdvanceLoc(MCContext &Context, OS << uint8_t(dwarf::DW_CFA_advance_loc1); OS << uint8_t(AddrDelta); } else if (isUInt<16>(AddrDelta)) { - // FIXME: check what is the correct behavior on a big endian machine. OS << uint8_t(dwarf::DW_CFA_advance_loc2); - OS << uint8_t( AddrDelta & 0xff); - OS << uint8_t((AddrDelta >> 8) & 0xff); + if (Context.getAsmInfo()->isLittleEndian()) + support::endian::Writer(OS).write(AddrDelta); + else + support::endian::Writer(OS).write(AddrDelta); } else { - // FIXME: check what is the correct behavior on a big endian machine. assert(isUInt<32>(AddrDelta)); OS << uint8_t(dwarf::DW_CFA_advance_loc4); - OS << uint8_t( AddrDelta & 0xff); - OS << uint8_t((AddrDelta >> 8) & 0xff); - OS << uint8_t((AddrDelta >> 16) & 0xff); - OS << uint8_t((AddrDelta >> 24) & 0xff); - + if (Context.getAsmInfo()->isLittleEndian()) + support::endian::Writer(OS).write(AddrDelta); + else + support::endian::Writer(OS).write(AddrDelta); } }