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Diffstat (limited to 'lib/DebugInfo/DWARFDebugFrame.cpp')
| -rw-r--r-- | lib/DebugInfo/DWARFDebugFrame.cpp | 374 |
1 files changed, 0 insertions, 374 deletions
diff --git a/lib/DebugInfo/DWARFDebugFrame.cpp b/lib/DebugInfo/DWARFDebugFrame.cpp deleted file mode 100644 index dfa7e82..0000000 --- a/lib/DebugInfo/DWARFDebugFrame.cpp +++ /dev/null @@ -1,374 +0,0 @@ -//===-- DWARFDebugFrame.h - Parsing of .debug_frame -------------*- C++ -*-===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// - -#include "DWARFDebugFrame.h" -#include "llvm/ADT/SmallString.h" -#include "llvm/Support/DataTypes.h" -#include "llvm/Support/Dwarf.h" -#include "llvm/Support/ErrorHandling.h" -#include "llvm/Support/Format.h" -#include "llvm/Support/raw_ostream.h" -#include <string> -#include <vector> - -using namespace llvm; -using namespace dwarf; - - -/// \brief Abstract frame entry defining the common interface concrete -/// entries implement. -class llvm::FrameEntry { -public: - enum FrameKind {FK_CIE, FK_FDE}; - FrameEntry(FrameKind K, uint64_t Offset, uint64_t Length) - : Kind(K), Offset(Offset), Length(Length) {} - - virtual ~FrameEntry() { - } - - FrameKind getKind() const { return Kind; } - virtual uint64_t getOffset() const { return Offset; } - - /// \brief Parse and store a sequence of CFI instructions from Data, - /// starting at *Offset and ending at EndOffset. If everything - /// goes well, *Offset should be equal to EndOffset when this method - /// returns. Otherwise, an error occurred. - virtual void parseInstructions(DataExtractor Data, uint32_t *Offset, - uint32_t EndOffset); - - /// \brief Dump the entry header to the given output stream. - virtual void dumpHeader(raw_ostream &OS) const = 0; - - /// \brief Dump the entry's instructions to the given output stream. - virtual void dumpInstructions(raw_ostream &OS) const; - -protected: - const FrameKind Kind; - - /// \brief Offset of this entry in the section. - uint64_t Offset; - - /// \brief Entry length as specified in DWARF. - uint64_t Length; - - /// An entry may contain CFI instructions. An instruction consists of an - /// opcode and an optional sequence of operands. - typedef std::vector<uint64_t> Operands; - struct Instruction { - Instruction(uint8_t Opcode) - : Opcode(Opcode) - {} - - uint8_t Opcode; - Operands Ops; - }; - - std::vector<Instruction> Instructions; - - /// Convenience methods to add a new instruction with the given opcode and - /// operands to the Instructions vector. - void addInstruction(uint8_t Opcode) { - Instructions.push_back(Instruction(Opcode)); - } - - void addInstruction(uint8_t Opcode, uint64_t Operand1) { - Instructions.push_back(Instruction(Opcode)); - Instructions.back().Ops.push_back(Operand1); - } - - void addInstruction(uint8_t Opcode, uint64_t Operand1, uint64_t Operand2) { - Instructions.push_back(Instruction(Opcode)); - Instructions.back().Ops.push_back(Operand1); - Instructions.back().Ops.push_back(Operand2); - } -}; - - -// 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; - -void FrameEntry::parseInstructions(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: llvm_unreachable("Impossible primary CFI opcode"); - 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: llvm_unreachable("Invalid extended CFI opcode"); - 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: - // 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 - addInstruction(Opcode, Data.getULEB128(Offset), - Data.getULEB128(Offset)); - break; - case DW_CFA_offset_extended_sf: - case DW_CFA_def_cfa_sf: - case DW_CFA_val_offset_sf: - // Operands: ULEB128, SLEB128 - addInstruction(Opcode, Data.getULEB128(Offset), - Data.getSLEB128(Offset)); - break; - case DW_CFA_def_cfa_expression: - case DW_CFA_expression: - case DW_CFA_val_expression: - // TODO: implement this - report_fatal_error("Values with expressions not implemented yet!"); - } - } - } -} - - -void FrameEntry::dumpInstructions(raw_ostream &OS) const { - // TODO: at the moment only instruction names are dumped. Expand this to - // dump operands as well. - for (const auto &Instr : Instructions) { - uint8_t Opcode = Instr.Opcode; - if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK) - Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK; - OS << " " << CallFrameString(Opcode) << ":\n"; - } -} - - -namespace { -/// \brief DWARF Common Information Entry (CIE) -class CIE : public FrameEntry { -public: - // CIEs (and FDEs) are simply container classes, so the only sensible way to - // create them is by providing the full parsed contents in the constructor. - CIE(uint64_t Offset, uint64_t Length, uint8_t Version, - SmallString<8> Augmentation, uint64_t CodeAlignmentFactor, - int64_t DataAlignmentFactor, uint64_t ReturnAddressRegister) - : FrameEntry(FK_CIE, Offset, Length), Version(Version), - Augmentation(std::move(Augmentation)), - CodeAlignmentFactor(CodeAlignmentFactor), - DataAlignmentFactor(DataAlignmentFactor), - ReturnAddressRegister(ReturnAddressRegister) {} - - ~CIE() { - } - - void dumpHeader(raw_ostream &OS) const override { - 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"; - 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); - OS << "\n"; - } - - static bool classof(const FrameEntry *FE) { - return FE->getKind() == FK_CIE; - } - -private: - /// The following fields are defined in section 6.4.1 of the DWARF standard v3 - uint8_t Version; - SmallString<8> Augmentation; - uint64_t CodeAlignmentFactor; - int64_t DataAlignmentFactor; - uint64_t ReturnAddressRegister; -}; - - -/// \brief DWARF Frame Description Entry (FDE) -class FDE : public FrameEntry { -public: - // Each FDE has a CIE it's "linked to". Our FDE contains is constructed with - // an offset to the CIE (provided by parsing the FDE header). The CIE itself - // is obtained lazily once it's actually required. - FDE(uint64_t Offset, uint64_t Length, int64_t LinkedCIEOffset, - uint64_t InitialLocation, uint64_t AddressRange) - : FrameEntry(FK_FDE, Offset, Length), LinkedCIEOffset(LinkedCIEOffset), - InitialLocation(InitialLocation), AddressRange(AddressRange), - LinkedCIE(nullptr) {} - - ~FDE() { - } - - void dumpHeader(raw_ostream &OS) const override { - 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 (LinkedCIE) { - OS << format("%p\n", LinkedCIE); - } - } - - static bool classof(const FrameEntry *FE) { - return FE->getKind() == FK_FDE; - } - -private: - /// The following fields are defined in section 6.4.1 of the DWARF standard v3 - uint64_t LinkedCIEOffset; - uint64_t InitialLocation; - uint64_t AddressRange; - CIE *LinkedCIE; -}; -} // end anonymous namespace - - -DWARFDebugFrame::DWARFDebugFrame() { -} - -DWARFDebugFrame::~DWARFDebugFrame() { -} - -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"; -} - - -void DWARFDebugFrame::parse(DataExtractor Data) { - uint32_t Offset = 0; - - 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 EndStructureOffset = Offset + static_cast<uint32_t>(Length); - - // The Id field's size depends on the DWARF format - Id = Data.getUnsigned(&Offset, IsDWARF64 ? 8 : 4); - bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID); - - if (IsCIE) { - // Note: this is specifically DWARFv3 CIE header structure. It was - // changed in DWARFv4. We currently don't support reading DWARFv4 - // here because LLVM itself does not emit it (and LLDB doesn't - // support it either). - uint8_t Version = Data.getU8(&Offset); - const char *Augmentation = Data.getCStr(&Offset); - uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset); - int64_t DataAlignmentFactor = Data.getSLEB128(&Offset); - uint64_t ReturnAddressRegister = Data.getULEB128(&Offset); - - Entries.emplace_back(new CIE(StartOffset, Length, Version, - StringRef(Augmentation), CodeAlignmentFactor, - DataAlignmentFactor, ReturnAddressRegister)); - } else { - // FDE - uint64_t CIEPointer = Id; - uint64_t InitialLocation = Data.getAddress(&Offset); - uint64_t AddressRange = Data.getAddress(&Offset); - - Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer, - InitialLocation, AddressRange)); - } - - Entries.back()->parseInstructions(Data, &Offset, EndStructureOffset); - - if (Offset != EndStructureOffset) { - std::string Str; - raw_string_ostream OS(Str); - OS << format("Parsing entry instructions at %lx failed", StartOffset); - report_fatal_error(Str); - } - } -} - - -void DWARFDebugFrame::dump(raw_ostream &OS) const { - OS << "\n"; - for (const auto &Entry : Entries) { - Entry->dumpHeader(OS); - Entry->dumpInstructions(OS); - OS << "\n"; - } -} - |