| //===- DWARFDebugFrame.h - Parsing of .debug_frame ------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/BinaryFormat/Dwarf.h" |
| #include "llvm/Support/Casting.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Support/DataExtractor.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/Format.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <algorithm> |
| #include <cassert> |
| #include <cinttypes> |
| #include <cstdint> |
| #include <string> |
| #include <vector> |
| |
| using namespace llvm; |
| using namespace dwarf; |
| |
| |
| // See DWARF standard v3, section 7.23 |
| const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0; |
| const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f; |
| |
| Error CFIProgram::parse(DataExtractor Data, uint32_t *Offset, |
| uint32_t EndOffset) { |
| while (*Offset < EndOffset) { |
| uint8_t Opcode = Data.getU8(Offset); |
| // Some instructions have a primary opcode encoded in the top bits. |
| uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK; |
| |
| if (Primary) { |
| // If it's a primary opcode, the first operand is encoded in the bottom |
| // bits of the opcode itself. |
| uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK; |
| switch (Primary) { |
| default: |
| return make_error<StringError>( |
| "Invalid primary CFI opcode", |
| std::make_error_code(std::errc::illegal_byte_sequence)); |
| case DW_CFA_advance_loc: |
| case DW_CFA_restore: |
| addInstruction(Primary, Op1); |
| break; |
| case DW_CFA_offset: |
| addInstruction(Primary, Op1, Data.getULEB128(Offset)); |
| break; |
| } |
| } else { |
| // Extended opcode - its value is Opcode itself. |
| switch (Opcode) { |
| default: |
| return make_error<StringError>( |
| "Invalid extended CFI opcode", |
| std::make_error_code(std::errc::illegal_byte_sequence)); |
| case DW_CFA_nop: |
| case DW_CFA_remember_state: |
| case DW_CFA_restore_state: |
| case DW_CFA_GNU_window_save: |
| // No operands |
| addInstruction(Opcode); |
| break; |
| case DW_CFA_set_loc: |
| // Operands: Address |
| addInstruction(Opcode, Data.getAddress(Offset)); |
| break; |
| case DW_CFA_advance_loc1: |
| // Operands: 1-byte delta |
| addInstruction(Opcode, Data.getU8(Offset)); |
| break; |
| case DW_CFA_advance_loc2: |
| // Operands: 2-byte delta |
| addInstruction(Opcode, Data.getU16(Offset)); |
| break; |
| case DW_CFA_advance_loc4: |
| // Operands: 4-byte delta |
| addInstruction(Opcode, Data.getU32(Offset)); |
| break; |
| case DW_CFA_restore_extended: |
| case DW_CFA_undefined: |
| case DW_CFA_same_value: |
| case DW_CFA_def_cfa_register: |
| case DW_CFA_def_cfa_offset: |
| case DW_CFA_GNU_args_size: |
| // Operands: ULEB128 |
| addInstruction(Opcode, Data.getULEB128(Offset)); |
| break; |
| case DW_CFA_def_cfa_offset_sf: |
| // Operands: SLEB128 |
| addInstruction(Opcode, Data.getSLEB128(Offset)); |
| break; |
| case DW_CFA_offset_extended: |
| case DW_CFA_register: |
| case DW_CFA_def_cfa: |
| case DW_CFA_val_offset: { |
| // Operands: ULEB128, ULEB128 |
| // Note: We can not embed getULEB128 directly into function |
| // argument list. getULEB128 changes Offset and order of evaluation |
| // for arguments is unspecified. |
| auto op1 = Data.getULEB128(Offset); |
| auto op2 = Data.getULEB128(Offset); |
| addInstruction(Opcode, op1, op2); |
| break; |
| } |
| case DW_CFA_offset_extended_sf: |
| case DW_CFA_def_cfa_sf: |
| case DW_CFA_val_offset_sf: { |
| // Operands: ULEB128, SLEB128 |
| // Note: see comment for the previous case |
| auto op1 = Data.getULEB128(Offset); |
| auto op2 = (uint64_t)Data.getSLEB128(Offset); |
| addInstruction(Opcode, op1, op2); |
| break; |
| } |
| case DW_CFA_def_cfa_expression: { |
| uint32_t ExprLength = Data.getULEB128(Offset); |
| addInstruction(Opcode, 0); |
| DataExtractor Extractor( |
| Data.getData().slice(*Offset, *Offset + ExprLength), |
| Data.isLittleEndian(), Data.getAddressSize()); |
| Instructions.back().Expression = DWARFExpression( |
| Extractor, Data.getAddressSize(), dwarf::DWARF_VERSION); |
| *Offset += ExprLength; |
| break; |
| } |
| case DW_CFA_expression: |
| case DW_CFA_val_expression: { |
| auto RegNum = Data.getULEB128(Offset); |
| auto BlockLength = Data.getULEB128(Offset); |
| addInstruction(Opcode, RegNum, 0); |
| DataExtractor Extractor( |
| Data.getData().slice(*Offset, *Offset + BlockLength), |
| Data.isLittleEndian(), Data.getAddressSize()); |
| Instructions.back().Expression = DWARFExpression( |
| Extractor, Data.getAddressSize(), dwarf::DWARF_VERSION); |
| *Offset += BlockLength; |
| break; |
| } |
| } |
| } |
| } |
| |
| return Error::success(); |
| } |
| |
| namespace { |
| |
| |
| } // end anonymous namespace |
| |
| ArrayRef<CFIProgram::OperandType[2]> CFIProgram::getOperandTypes() { |
| static OperandType OpTypes[DW_CFA_restore+1][2]; |
| static bool Initialized = false; |
| if (Initialized) { |
| return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1); |
| } |
| Initialized = true; |
| |
| #define DECLARE_OP2(OP, OPTYPE0, OPTYPE1) \ |
| do { \ |
| OpTypes[OP][0] = OPTYPE0; \ |
| OpTypes[OP][1] = OPTYPE1; \ |
| } while (false) |
| #define DECLARE_OP1(OP, OPTYPE0) DECLARE_OP2(OP, OPTYPE0, OT_None) |
| #define DECLARE_OP0(OP) DECLARE_OP1(OP, OT_None) |
| |
| DECLARE_OP1(DW_CFA_set_loc, OT_Address); |
| DECLARE_OP1(DW_CFA_advance_loc, OT_FactoredCodeOffset); |
| DECLARE_OP1(DW_CFA_advance_loc1, OT_FactoredCodeOffset); |
| DECLARE_OP1(DW_CFA_advance_loc2, OT_FactoredCodeOffset); |
| DECLARE_OP1(DW_CFA_advance_loc4, OT_FactoredCodeOffset); |
| DECLARE_OP1(DW_CFA_MIPS_advance_loc8, OT_FactoredCodeOffset); |
| DECLARE_OP2(DW_CFA_def_cfa, OT_Register, OT_Offset); |
| DECLARE_OP2(DW_CFA_def_cfa_sf, OT_Register, OT_SignedFactDataOffset); |
| DECLARE_OP1(DW_CFA_def_cfa_register, OT_Register); |
| DECLARE_OP1(DW_CFA_def_cfa_offset, OT_Offset); |
| DECLARE_OP1(DW_CFA_def_cfa_offset_sf, OT_SignedFactDataOffset); |
| DECLARE_OP1(DW_CFA_def_cfa_expression, OT_Expression); |
| DECLARE_OP1(DW_CFA_undefined, OT_Register); |
| DECLARE_OP1(DW_CFA_same_value, OT_Register); |
| DECLARE_OP2(DW_CFA_offset, OT_Register, OT_UnsignedFactDataOffset); |
| DECLARE_OP2(DW_CFA_offset_extended, OT_Register, OT_UnsignedFactDataOffset); |
| DECLARE_OP2(DW_CFA_offset_extended_sf, OT_Register, OT_SignedFactDataOffset); |
| DECLARE_OP2(DW_CFA_val_offset, OT_Register, OT_UnsignedFactDataOffset); |
| DECLARE_OP2(DW_CFA_val_offset_sf, OT_Register, OT_SignedFactDataOffset); |
| DECLARE_OP2(DW_CFA_register, OT_Register, OT_Register); |
| DECLARE_OP2(DW_CFA_expression, OT_Register, OT_Expression); |
| DECLARE_OP2(DW_CFA_val_expression, OT_Register, OT_Expression); |
| DECLARE_OP1(DW_CFA_restore, OT_Register); |
| DECLARE_OP1(DW_CFA_restore_extended, OT_Register); |
| DECLARE_OP0(DW_CFA_remember_state); |
| DECLARE_OP0(DW_CFA_restore_state); |
| DECLARE_OP0(DW_CFA_GNU_window_save); |
| DECLARE_OP1(DW_CFA_GNU_args_size, OT_Offset); |
| DECLARE_OP0(DW_CFA_nop); |
| |
| #undef DECLARE_OP0 |
| #undef DECLARE_OP1 |
| #undef DECLARE_OP2 |
| |
| return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1); |
| } |
| |
| /// Print \p Opcode's operand number \p OperandIdx which has value \p Operand. |
| void CFIProgram::printOperand(raw_ostream &OS, const MCRegisterInfo *MRI, |
| bool IsEH, const Instruction &Instr, |
| unsigned OperandIdx, uint64_t Operand) const { |
| assert(OperandIdx < 2); |
| uint8_t Opcode = Instr.Opcode; |
| OperandType Type = getOperandTypes()[Opcode][OperandIdx]; |
| |
| switch (Type) { |
| case OT_Unset: { |
| OS << " Unsupported " << (OperandIdx ? "second" : "first") << " operand to"; |
| auto OpcodeName = CallFrameString(Opcode); |
| if (!OpcodeName.empty()) |
| OS << " " << OpcodeName; |
| else |
| OS << format(" Opcode %x", Opcode); |
| break; |
| } |
| case OT_None: |
| break; |
| case OT_Address: |
| OS << format(" %" PRIx64, Operand); |
| break; |
| case OT_Offset: |
| // The offsets are all encoded in a unsigned form, but in practice |
| // consumers use them signed. It's most certainly legacy due to |
| // the lack of signed variants in the first Dwarf standards. |
| OS << format(" %+" PRId64, int64_t(Operand)); |
| break; |
| case OT_FactoredCodeOffset: // Always Unsigned |
| if (CodeAlignmentFactor) |
| OS << format(" %" PRId64, Operand * CodeAlignmentFactor); |
| else |
| OS << format(" %" PRId64 "*code_alignment_factor" , Operand); |
| break; |
| case OT_SignedFactDataOffset: |
| if (DataAlignmentFactor) |
| OS << format(" %" PRId64, int64_t(Operand) * DataAlignmentFactor); |
| else |
| OS << format(" %" PRId64 "*data_alignment_factor" , int64_t(Operand)); |
| break; |
| case OT_UnsignedFactDataOffset: |
| if (DataAlignmentFactor) |
| OS << format(" %" PRId64, Operand * DataAlignmentFactor); |
| else |
| OS << format(" %" PRId64 "*data_alignment_factor" , Operand); |
| break; |
| case OT_Register: |
| OS << format(" reg%" PRId64, Operand); |
| break; |
| case OT_Expression: |
| assert(Instr.Expression && "missing DWARFExpression object"); |
| OS << " "; |
| Instr.Expression->print(OS, MRI, IsEH); |
| break; |
| } |
| } |
| |
| void CFIProgram::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH, |
| unsigned IndentLevel) const { |
| for (const auto &Instr : Instructions) { |
| uint8_t Opcode = Instr.Opcode; |
| if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK) |
| Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK; |
| OS.indent(2 * IndentLevel); |
| OS << CallFrameString(Opcode) << ":"; |
| for (unsigned i = 0; i < Instr.Ops.size(); ++i) |
| printOperand(OS, MRI, IsEH, Instr, i, Instr.Ops[i]); |
| OS << '\n'; |
| } |
| } |
| |
| void CIE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const { |
| OS << format("%08x %08x %08x CIE", (uint32_t)Offset, (uint32_t)Length, |
| DW_CIE_ID) |
| << "\n"; |
| OS << format(" Version: %d\n", Version); |
| OS << " Augmentation: \"" << Augmentation << "\"\n"; |
| if (Version >= 4) { |
| OS << format(" Address size: %u\n", (uint32_t)AddressSize); |
| OS << format(" Segment desc size: %u\n", |
| (uint32_t)SegmentDescriptorSize); |
| } |
| OS << format(" Code alignment factor: %u\n", (uint32_t)CodeAlignmentFactor); |
| OS << format(" Data alignment factor: %d\n", (int32_t)DataAlignmentFactor); |
| OS << format(" Return address column: %d\n", (int32_t)ReturnAddressRegister); |
| if (Personality) |
| OS << format(" Personality Address: %08x\n", *Personality); |
| if (!AugmentationData.empty()) { |
| OS << " Augmentation data: "; |
| for (uint8_t Byte : AugmentationData) |
| OS << ' ' << hexdigit(Byte >> 4) << hexdigit(Byte & 0xf); |
| OS << "\n"; |
| } |
| OS << "\n"; |
| CFIs.dump(OS, MRI, IsEH); |
| OS << "\n"; |
| } |
| |
| void FDE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const { |
| OS << format("%08x %08x %08x FDE ", (uint32_t)Offset, (uint32_t)Length, |
| (int32_t)LinkedCIEOffset); |
| OS << format("cie=%08x pc=%08x...%08x\n", (int32_t)LinkedCIEOffset, |
| (uint32_t)InitialLocation, |
| (uint32_t)InitialLocation + (uint32_t)AddressRange); |
| if (LSDAAddress) |
| OS << format(" LSDA Address: %08x\n", *LSDAAddress); |
| CFIs.dump(OS, MRI, IsEH); |
| OS << "\n"; |
| } |
| |
| DWARFDebugFrame::DWARFDebugFrame(bool IsEH, uint64_t EHFrameAddress) |
| : IsEH(IsEH), EHFrameAddress(EHFrameAddress) {} |
| |
| DWARFDebugFrame::~DWARFDebugFrame() = default; |
| |
| static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data, |
| uint32_t Offset, int Length) { |
| errs() << "DUMP: "; |
| for (int i = 0; i < Length; ++i) { |
| uint8_t c = Data.getU8(&Offset); |
| errs().write_hex(c); errs() << " "; |
| } |
| errs() << "\n"; |
| } |
| |
| // This is a workaround for old compilers which do not allow |
| // noreturn attribute usage in lambdas. Once the support for those |
| // compilers are phased out, we can remove this and return back to |
| // a ReportError lambda: [StartOffset](const char *ErrorMsg). |
| static void LLVM_ATTRIBUTE_NORETURN ReportError(uint32_t StartOffset, |
| const char *ErrorMsg) { |
| std::string Str; |
| raw_string_ostream OS(Str); |
| OS << format(ErrorMsg, StartOffset); |
| OS.flush(); |
| report_fatal_error(Str); |
| } |
| |
| void DWARFDebugFrame::parse(DWARFDataExtractor Data) { |
| uint32_t Offset = 0; |
| DenseMap<uint32_t, CIE *> CIEs; |
| |
| while (Data.isValidOffset(Offset)) { |
| uint32_t StartOffset = Offset; |
| |
| bool IsDWARF64 = false; |
| uint64_t Length = Data.getU32(&Offset); |
| uint64_t Id; |
| |
| if (Length == UINT32_MAX) { |
| // DWARF-64 is distinguished by the first 32 bits of the initial length |
| // field being 0xffffffff. Then, the next 64 bits are the actual entry |
| // length. |
| IsDWARF64 = true; |
| Length = Data.getU64(&Offset); |
| } |
| |
| // At this point, Offset points to the next field after Length. |
| // Length is the structure size excluding itself. Compute an offset one |
| // past the end of the structure (needed to know how many instructions to |
| // read). |
| // TODO: For honest DWARF64 support, DataExtractor will have to treat |
| // offset_ptr as uint64_t* |
| uint32_t StartStructureOffset = Offset; |
| uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length); |
| |
| // The Id field's size depends on the DWARF format |
| Id = Data.getUnsigned(&Offset, (IsDWARF64 && !IsEH) ? 8 : 4); |
| bool IsCIE = |
| ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID || (IsEH && !Id)); |
| |
| if (IsCIE) { |
| uint8_t Version = Data.getU8(&Offset); |
| const char *Augmentation = Data.getCStr(&Offset); |
| StringRef AugmentationString(Augmentation ? Augmentation : ""); |
| uint8_t AddressSize = Version < 4 ? Data.getAddressSize() : |
| Data.getU8(&Offset); |
| Data.setAddressSize(AddressSize); |
| uint8_t SegmentDescriptorSize = Version < 4 ? 0 : Data.getU8(&Offset); |
| uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset); |
| int64_t DataAlignmentFactor = Data.getSLEB128(&Offset); |
| uint64_t ReturnAddressRegister = Data.getULEB128(&Offset); |
| |
| // Parse the augmentation data for EH CIEs |
| StringRef AugmentationData(""); |
| uint32_t FDEPointerEncoding = DW_EH_PE_absptr; |
| uint32_t LSDAPointerEncoding = DW_EH_PE_omit; |
| Optional<uint64_t> Personality; |
| Optional<uint32_t> PersonalityEncoding; |
| if (IsEH) { |
| Optional<uint64_t> AugmentationLength; |
| uint32_t StartAugmentationOffset; |
| uint32_t EndAugmentationOffset; |
| |
| // Walk the augmentation string to get all the augmentation data. |
| for (unsigned i = 0, e = AugmentationString.size(); i != e; ++i) { |
| switch (AugmentationString[i]) { |
| default: |
| ReportError(StartOffset, |
| "Unknown augmentation character in entry at %lx"); |
| case 'L': |
| LSDAPointerEncoding = Data.getU8(&Offset); |
| break; |
| case 'P': { |
| if (Personality) |
| ReportError(StartOffset, |
| "Duplicate personality in entry at %lx"); |
| PersonalityEncoding = Data.getU8(&Offset); |
| Personality = Data.getEncodedPointer( |
| &Offset, *PersonalityEncoding, |
| EHFrameAddress ? EHFrameAddress + Offset : 0); |
| break; |
| } |
| case 'R': |
| FDEPointerEncoding = Data.getU8(&Offset); |
| break; |
| case 'S': |
| // Current frame is a signal trampoline. |
| break; |
| case 'z': |
| if (i) |
| ReportError(StartOffset, |
| "'z' must be the first character at %lx"); |
| // Parse the augmentation length first. We only parse it if |
| // the string contains a 'z'. |
| AugmentationLength = Data.getULEB128(&Offset); |
| StartAugmentationOffset = Offset; |
| EndAugmentationOffset = Offset + |
| static_cast<uint32_t>(*AugmentationLength); |
| } |
| } |
| |
| if (AugmentationLength.hasValue()) { |
| if (Offset != EndAugmentationOffset) |
| ReportError(StartOffset, "Parsing augmentation data at %lx failed"); |
| |
| AugmentationData = Data.getData().slice(StartAugmentationOffset, |
| EndAugmentationOffset); |
| } |
| } |
| |
| auto Cie = llvm::make_unique<CIE>( |
| StartOffset, Length, Version, AugmentationString, AddressSize, |
| SegmentDescriptorSize, CodeAlignmentFactor, DataAlignmentFactor, |
| ReturnAddressRegister, AugmentationData, FDEPointerEncoding, |
| LSDAPointerEncoding, Personality, PersonalityEncoding); |
| CIEs[StartOffset] = Cie.get(); |
| Entries.emplace_back(std::move(Cie)); |
| } else { |
| // FDE |
| uint64_t CIEPointer = Id; |
| uint64_t InitialLocation = 0; |
| uint64_t AddressRange = 0; |
| Optional<uint64_t> LSDAAddress; |
| CIE *Cie = CIEs[IsEH ? (StartStructureOffset - CIEPointer) : CIEPointer]; |
| |
| if (IsEH) { |
| // The address size is encoded in the CIE we reference. |
| if (!Cie) |
| ReportError(StartOffset, |
| "Parsing FDE data at %lx failed due to missing CIE"); |
| |
| if (auto Val = Data.getEncodedPointer( |
| &Offset, Cie->getFDEPointerEncoding(), |
| EHFrameAddress ? EHFrameAddress + Offset : 0)) { |
| InitialLocation = *Val; |
| } |
| if (auto Val = Data.getEncodedPointer( |
| &Offset, Cie->getFDEPointerEncoding(), 0)) { |
| AddressRange = *Val; |
| } |
| |
| StringRef AugmentationString = Cie->getAugmentationString(); |
| if (!AugmentationString.empty()) { |
| // Parse the augmentation length and data for this FDE. |
| uint64_t AugmentationLength = Data.getULEB128(&Offset); |
| |
| uint32_t EndAugmentationOffset = |
| Offset + static_cast<uint32_t>(AugmentationLength); |
| |
| // Decode the LSDA if the CIE augmentation string said we should. |
| if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit) { |
| LSDAAddress = Data.getEncodedPointer( |
| &Offset, Cie->getLSDAPointerEncoding(), |
| EHFrameAddress ? Offset + EHFrameAddress : 0); |
| } |
| |
| if (Offset != EndAugmentationOffset) |
| ReportError(StartOffset, "Parsing augmentation data at %lx failed"); |
| } |
| } else { |
| InitialLocation = Data.getAddress(&Offset); |
| AddressRange = Data.getAddress(&Offset); |
| } |
| |
| Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer, |
| InitialLocation, AddressRange, |
| Cie, LSDAAddress)); |
| } |
| |
| if (Error E = |
| Entries.back()->cfis().parse(Data, &Offset, EndStructureOffset)) { |
| report_fatal_error(toString(std::move(E))); |
| } |
| |
| if (Offset != EndStructureOffset) |
| ReportError(StartOffset, "Parsing entry instructions at %lx failed"); |
| } |
| } |
| |
| FrameEntry *DWARFDebugFrame::getEntryAtOffset(uint64_t Offset) const { |
| auto It = |
| std::lower_bound(Entries.begin(), Entries.end(), Offset, |
| [](const std::unique_ptr<FrameEntry> &E, |
| uint64_t Offset) { return E->getOffset() < Offset; }); |
| if (It != Entries.end() && (*It)->getOffset() == Offset) |
| return It->get(); |
| return nullptr; |
| } |
| |
| void DWARFDebugFrame::dump(raw_ostream &OS, const MCRegisterInfo *MRI, |
| Optional<uint64_t> Offset) const { |
| if (Offset) { |
| if (auto *Entry = getEntryAtOffset(*Offset)) |
| Entry->dump(OS, MRI, IsEH); |
| return; |
| } |
| |
| OS << "\n"; |
| for (const auto &Entry : Entries) |
| Entry->dump(OS, MRI, IsEH); |
| } |
