diff options
Diffstat (limited to 'third_party/llvm-project/DWARFDebugLine.cpp')
| -rw-r--r-- | third_party/llvm-project/DWARFDebugLine.cpp | 1181 |
1 files changed, 1181 insertions, 0 deletions
diff --git a/third_party/llvm-project/DWARFDebugLine.cpp b/third_party/llvm-project/DWARFDebugLine.cpp new file mode 100644 index 000000000..dbee28ff5 --- /dev/null +++ b/third_party/llvm-project/DWARFDebugLine.cpp @@ -0,0 +1,1181 @@ +//===- DWARFDebugLine.cpp -------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h" +#include "llvm/ADT/Optional.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/BinaryFormat/Dwarf.h" +#include "llvm/DebugInfo/DWARF/DWARFFormValue.h" +#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h" +#include "llvm/Support/Errc.h" +#include "llvm/Support/Format.h" +#include "llvm/Support/WithColor.h" +#include "llvm/Support/raw_ostream.h" +#include <algorithm> +#include <cassert> +#include <cinttypes> +#include <cstdint> +#include <cstdio> +#include <utility> + +using namespace llvm; +using namespace dwarf; + +using FileLineInfoKind = DILineInfoSpecifier::FileLineInfoKind; + +namespace { + +struct ContentDescriptor { + dwarf::LineNumberEntryFormat Type; + dwarf::Form Form; +}; + +using ContentDescriptors = SmallVector<ContentDescriptor, 4>; + +} // end anonmyous namespace + +void DWARFDebugLine::ContentTypeTracker::trackContentType( + dwarf::LineNumberEntryFormat ContentType) { + switch (ContentType) { + case dwarf::DW_LNCT_timestamp: + HasModTime = true; + break; + case dwarf::DW_LNCT_size: + HasLength = true; + break; + case dwarf::DW_LNCT_MD5: + HasMD5 = true; + break; + case dwarf::DW_LNCT_LLVM_source: + HasSource = true; + break; + default: + // We only care about values we consider optional, and new values may be + // added in the vendor extension range, so we do not match exhaustively. + break; + } +} + +DWARFDebugLine::Prologue::Prologue() { clear(); } + +bool DWARFDebugLine::Prologue::hasFileAtIndex(uint64_t FileIndex) const { + uint16_t DwarfVersion = getVersion(); + assert(DwarfVersion != 0 && + "line table prologue has no dwarf version information"); + if (DwarfVersion >= 5) + return FileIndex < FileNames.size(); + return FileIndex != 0 && FileIndex <= FileNames.size(); +} + +const llvm::DWARFDebugLine::FileNameEntry & +DWARFDebugLine::Prologue::getFileNameEntry(uint64_t Index) const { + uint16_t DwarfVersion = getVersion(); + assert(DwarfVersion != 0 && + "line table prologue has no dwarf version information"); + // In DWARF v5 the file names are 0-indexed. + if (DwarfVersion >= 5) + return FileNames[Index]; + return FileNames[Index - 1]; +} + +void DWARFDebugLine::Prologue::clear() { + TotalLength = PrologueLength = 0; + SegSelectorSize = 0; + MinInstLength = MaxOpsPerInst = DefaultIsStmt = LineBase = LineRange = 0; + OpcodeBase = 0; + FormParams = dwarf::FormParams({0, 0, DWARF32}); + ContentTypes = ContentTypeTracker(); + StandardOpcodeLengths.clear(); + IncludeDirectories.clear(); + FileNames.clear(); +} + +void DWARFDebugLine::Prologue::dump(raw_ostream &OS, + DIDumpOptions DumpOptions) const { + OS << "Line table prologue:\n" + << format(" total_length: 0x%8.8" PRIx64 "\n", TotalLength) + << format(" version: %u\n", getVersion()); + if (getVersion() >= 5) + OS << format(" address_size: %u\n", getAddressSize()) + << format(" seg_select_size: %u\n", SegSelectorSize); + OS << format(" prologue_length: 0x%8.8" PRIx64 "\n", PrologueLength) + << format(" min_inst_length: %u\n", MinInstLength) + << format(getVersion() >= 4 ? "max_ops_per_inst: %u\n" : "", MaxOpsPerInst) + << format(" default_is_stmt: %u\n", DefaultIsStmt) + << format(" line_base: %i\n", LineBase) + << format(" line_range: %u\n", LineRange) + << format(" opcode_base: %u\n", OpcodeBase); + + for (uint32_t I = 0; I != StandardOpcodeLengths.size(); ++I) + OS << format("standard_opcode_lengths[%s] = %u\n", + LNStandardString(I + 1).data(), StandardOpcodeLengths[I]); + + if (!IncludeDirectories.empty()) { + // DWARF v5 starts directory indexes at 0. + uint32_t DirBase = getVersion() >= 5 ? 0 : 1; + for (uint32_t I = 0; I != IncludeDirectories.size(); ++I) { + OS << format("include_directories[%3u] = ", I + DirBase); + IncludeDirectories[I].dump(OS, DumpOptions); + OS << '\n'; + } + } + + if (!FileNames.empty()) { + // DWARF v5 starts file indexes at 0. + uint32_t FileBase = getVersion() >= 5 ? 0 : 1; + for (uint32_t I = 0; I != FileNames.size(); ++I) { + const FileNameEntry &FileEntry = FileNames[I]; + OS << format("file_names[%3u]:\n", I + FileBase); + OS << " name: "; + FileEntry.Name.dump(OS, DumpOptions); + OS << '\n' + << format(" dir_index: %" PRIu64 "\n", FileEntry.DirIdx); + if (ContentTypes.HasMD5) + OS << " md5_checksum: " << FileEntry.Checksum.digest() << '\n'; + if (ContentTypes.HasModTime) + OS << format(" mod_time: 0x%8.8" PRIx64 "\n", FileEntry.ModTime); + if (ContentTypes.HasLength) + OS << format(" length: 0x%8.8" PRIx64 "\n", FileEntry.Length); + if (ContentTypes.HasSource) { + OS << " source: "; + FileEntry.Source.dump(OS, DumpOptions); + OS << '\n'; + } + } + } +} + +// Parse v2-v4 directory and file tables. +static void +parseV2DirFileTables(const DWARFDataExtractor &DebugLineData, + uint64_t *OffsetPtr, uint64_t EndPrologueOffset, + DWARFDebugLine::ContentTypeTracker &ContentTypes, + std::vector<DWARFFormValue> &IncludeDirectories, + std::vector<DWARFDebugLine::FileNameEntry> &FileNames) { + while (*OffsetPtr < EndPrologueOffset) { + StringRef S = DebugLineData.getCStrRef(OffsetPtr); + if (S.empty()) + break; + DWARFFormValue Dir = + DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, S.data()); + IncludeDirectories.push_back(Dir); + } + + while (*OffsetPtr < EndPrologueOffset) { + StringRef Name = DebugLineData.getCStrRef(OffsetPtr); + if (Name.empty()) + break; + DWARFDebugLine::FileNameEntry FileEntry; + FileEntry.Name = + DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name.data()); + FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr); + FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr); + FileEntry.Length = DebugLineData.getULEB128(OffsetPtr); + FileNames.push_back(FileEntry); + } + + ContentTypes.HasModTime = true; + ContentTypes.HasLength = true; +} + +// Parse v5 directory/file entry content descriptions. +// Returns the descriptors, or an error if we did not find a path or ran off +// the end of the prologue. +static llvm::Expected<ContentDescriptors> +parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, + uint64_t EndPrologueOffset, + DWARFDebugLine::ContentTypeTracker *ContentTypes) { + ContentDescriptors Descriptors; + int FormatCount = DebugLineData.getU8(OffsetPtr); + bool HasPath = false; + for (int I = 0; I != FormatCount; ++I) { + if (*OffsetPtr >= EndPrologueOffset) + return createStringError( + errc::invalid_argument, + "failed to parse entry content descriptions at offset " + "0x%8.8" PRIx64 + " because offset extends beyond the prologue end at offset " + "0x%8.8" PRIx64, + *OffsetPtr, EndPrologueOffset); + ContentDescriptor Descriptor; + Descriptor.Type = + dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr)); + Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr)); + if (Descriptor.Type == dwarf::DW_LNCT_path) + HasPath = true; + if (ContentTypes) + ContentTypes->trackContentType(Descriptor.Type); + Descriptors.push_back(Descriptor); + } + + if (!HasPath) + return createStringError(errc::invalid_argument, + "failed to parse entry content descriptions" + " because no path was found"); + return Descriptors; +} + +static Error +parseV5DirFileTables(const DWARFDataExtractor &DebugLineData, + uint64_t *OffsetPtr, uint64_t EndPrologueOffset, + const dwarf::FormParams &FormParams, + const DWARFContext &Ctx, const DWARFUnit *U, + DWARFDebugLine::ContentTypeTracker &ContentTypes, + std::vector<DWARFFormValue> &IncludeDirectories, + std::vector<DWARFDebugLine::FileNameEntry> &FileNames) { + // Get the directory entry description. + llvm::Expected<ContentDescriptors> DirDescriptors = + parseV5EntryFormat(DebugLineData, OffsetPtr, EndPrologueOffset, nullptr); + if (!DirDescriptors) + return DirDescriptors.takeError(); + + // Get the directory entries, according to the format described above. + int DirEntryCount = DebugLineData.getU8(OffsetPtr); + for (int I = 0; I != DirEntryCount; ++I) { + if (*OffsetPtr >= EndPrologueOffset) + return createStringError( + errc::invalid_argument, + "failed to parse directory entry at offset " + "0x%8.8" PRIx64 + " because offset extends beyond the prologue end at offset " + "0x%8.8" PRIx64, + *OffsetPtr, EndPrologueOffset); + for (auto Descriptor : *DirDescriptors) { + DWARFFormValue Value(Descriptor.Form); + switch (Descriptor.Type) { + case DW_LNCT_path: + if (!Value.extractValue(DebugLineData, OffsetPtr, FormParams, &Ctx, U)) + return createStringError(errc::invalid_argument, + "failed to parse directory entry because " + "extracting the form value failed."); + IncludeDirectories.push_back(Value); + break; + default: + if (!Value.skipValue(DebugLineData, OffsetPtr, FormParams)) + return createStringError(errc::invalid_argument, + "failed to parse directory entry because " + "skipping the form value failed."); + } + } + } + + // Get the file entry description. + llvm::Expected<ContentDescriptors> FileDescriptors = parseV5EntryFormat( + DebugLineData, OffsetPtr, EndPrologueOffset, &ContentTypes); + if (!FileDescriptors) + return FileDescriptors.takeError(); + + // Get the file entries, according to the format described above. + int FileEntryCount = DebugLineData.getU8(OffsetPtr); + for (int I = 0; I != FileEntryCount; ++I) { + if (*OffsetPtr >= EndPrologueOffset) + return createStringError( + errc::invalid_argument, + "failed to parse file entry at offset " + "0x%8.8" PRIx64 + " because offset extends beyond the prologue end at offset " + "0x%8.8" PRIx64, + *OffsetPtr, EndPrologueOffset); + DWARFDebugLine::FileNameEntry FileEntry; + for (auto Descriptor : *FileDescriptors) { + DWARFFormValue Value(Descriptor.Form); + if (!Value.extractValue(DebugLineData, OffsetPtr, FormParams, &Ctx, U)) + return createStringError(errc::invalid_argument, + "failed to parse file entry because " + "extracting the form value failed."); + switch (Descriptor.Type) { + case DW_LNCT_path: + FileEntry.Name = Value; + break; + case DW_LNCT_LLVM_source: + FileEntry.Source = Value; + break; + case DW_LNCT_directory_index: + FileEntry.DirIdx = Value.getAsUnsignedConstant().getValue(); + break; + case DW_LNCT_timestamp: + FileEntry.ModTime = Value.getAsUnsignedConstant().getValue(); + break; + case DW_LNCT_size: + FileEntry.Length = Value.getAsUnsignedConstant().getValue(); + break; + case DW_LNCT_MD5: + if (!Value.getAsBlock() || Value.getAsBlock().getValue().size() != 16) + return createStringError( + errc::invalid_argument, + "failed to parse file entry because the MD5 hash is invalid"); + std::uninitialized_copy_n(Value.getAsBlock().getValue().begin(), 16, + FileEntry.Checksum.Bytes.begin()); + break; + default: + break; + } + } + FileNames.push_back(FileEntry); + } + return Error::success(); +} + +Error DWARFDebugLine::Prologue::parse(const DWARFDataExtractor &DebugLineData, + uint64_t *OffsetPtr, + const DWARFContext &Ctx, + const DWARFUnit *U) { + const uint64_t PrologueOffset = *OffsetPtr; + + clear(); + TotalLength = DebugLineData.getRelocatedValue(4, OffsetPtr); + if (TotalLength == dwarf::DW_LENGTH_DWARF64) { + FormParams.Format = dwarf::DWARF64; + TotalLength = DebugLineData.getU64(OffsetPtr); + } else if (TotalLength >= dwarf::DW_LENGTH_lo_reserved) { + return createStringError(errc::invalid_argument, + "parsing line table prologue at offset 0x%8.8" PRIx64 + " unsupported reserved unit length found of value 0x%8.8" PRIx64, + PrologueOffset, TotalLength); + } + FormParams.Version = DebugLineData.getU16(OffsetPtr); + if (getVersion() < 2) + return createStringError(errc::not_supported, + "parsing line table prologue at offset 0x%8.8" PRIx64 + " found unsupported version 0x%2.2" PRIx16, + PrologueOffset, getVersion()); + + if (getVersion() >= 5) { + FormParams.AddrSize = DebugLineData.getU8(OffsetPtr); + assert((DebugLineData.getAddressSize() == 0 || + DebugLineData.getAddressSize() == getAddressSize()) && + "Line table header and data extractor disagree"); + SegSelectorSize = DebugLineData.getU8(OffsetPtr); + } + + PrologueLength = + DebugLineData.getRelocatedValue(sizeofPrologueLength(), OffsetPtr); + const uint64_t EndPrologueOffset = PrologueLength + *OffsetPtr; + MinInstLength = DebugLineData.getU8(OffsetPtr); + if (getVersion() >= 4) + MaxOpsPerInst = DebugLineData.getU8(OffsetPtr); + DefaultIsStmt = DebugLineData.getU8(OffsetPtr); + LineBase = DebugLineData.getU8(OffsetPtr); + LineRange = DebugLineData.getU8(OffsetPtr); + OpcodeBase = DebugLineData.getU8(OffsetPtr); + + StandardOpcodeLengths.reserve(OpcodeBase - 1); + for (uint32_t I = 1; I < OpcodeBase; ++I) { + uint8_t OpLen = DebugLineData.getU8(OffsetPtr); + StandardOpcodeLengths.push_back(OpLen); + } + + if (getVersion() >= 5) { + if (Error e = parseV5DirFileTables( + DebugLineData, OffsetPtr, EndPrologueOffset, FormParams, Ctx, U, + ContentTypes, IncludeDirectories, FileNames)) { + return joinErrors( + createStringError( + errc::invalid_argument, + "parsing line table prologue at 0x%8.8" PRIx64 + " found an invalid directory or file table description at" + " 0x%8.8" PRIx64, + PrologueOffset, *OffsetPtr), + std::move(e)); + } + } else + parseV2DirFileTables(DebugLineData, OffsetPtr, EndPrologueOffset, + ContentTypes, IncludeDirectories, FileNames); + + if (*OffsetPtr != EndPrologueOffset) + return createStringError(errc::invalid_argument, + "parsing line table prologue at 0x%8.8" PRIx64 + " should have ended at 0x%8.8" PRIx64 + " but it ended at 0x%8.8" PRIx64, + PrologueOffset, EndPrologueOffset, *OffsetPtr); + return Error::success(); +} + +DWARFDebugLine::Row::Row(bool DefaultIsStmt) { reset(DefaultIsStmt); } + +void DWARFDebugLine::Row::postAppend() { + Discriminator = 0; + BasicBlock = false; + PrologueEnd = false; + EpilogueBegin = false; +} + +void DWARFDebugLine::Row::reset(bool DefaultIsStmt) { + Address.Address = 0; + Address.SectionIndex = object::SectionedAddress::UndefSection; + Line = 1; + Column = 0; + File = 1; + Isa = 0; + Discriminator = 0; + IsStmt = DefaultIsStmt; + BasicBlock = false; + EndSequence = false; + PrologueEnd = false; + EpilogueBegin = false; +} + +void DWARFDebugLine::Row::dumpTableHeader(raw_ostream &OS) { + OS << "Address Line Column File ISA Discriminator Flags\n" + << "------------------ ------ ------ ------ --- ------------- " + "-------------\n"; +} + +void DWARFDebugLine::Row::dump(raw_ostream &OS) const { + OS << format("0x%16.16" PRIx64 " %6u %6u", Address.Address, Line, Column) + << format(" %6u %3u %13u ", File, Isa, Discriminator) + << (IsStmt ? " is_stmt" : "") << (BasicBlock ? " basic_block" : "") + << (PrologueEnd ? " prologue_end" : "") + << (EpilogueBegin ? " epilogue_begin" : "") + << (EndSequence ? " end_sequence" : "") << '\n'; +} + +DWARFDebugLine::Sequence::Sequence() { reset(); } + +void DWARFDebugLine::Sequence::reset() { + LowPC = 0; + HighPC = 0; + SectionIndex = object::SectionedAddress::UndefSection; + FirstRowIndex = 0; + LastRowIndex = 0; + Empty = true; +} + +DWARFDebugLine::LineTable::LineTable() { clear(); } + +void DWARFDebugLine::LineTable::dump(raw_ostream &OS, + DIDumpOptions DumpOptions) const { + Prologue.dump(OS, DumpOptions); + OS << '\n'; + + if (!Rows.empty()) { + Row::dumpTableHeader(OS); + for (const Row &R : Rows) { + R.dump(OS); + } + } +} + +void DWARFDebugLine::LineTable::clear() { + Prologue.clear(); + Rows.clear(); + Sequences.clear(); +} + +DWARFDebugLine::ParsingState::ParsingState(struct LineTable *LT) + : LineTable(LT) { + resetRowAndSequence(); +} + +void DWARFDebugLine::ParsingState::resetRowAndSequence() { + Row.reset(LineTable->Prologue.DefaultIsStmt); + Sequence.reset(); +} + +void DWARFDebugLine::ParsingState::appendRowToMatrix() { + unsigned RowNumber = LineTable->Rows.size(); + if (Sequence.Empty) { + // Record the beginning of instruction sequence. + Sequence.Empty = false; + Sequence.LowPC = Row.Address.Address; + Sequence.FirstRowIndex = RowNumber; + } + LineTable->appendRow(Row); + if (Row.EndSequence) { + // Record the end of instruction sequence. + Sequence.HighPC = Row.Address.Address; + Sequence.LastRowIndex = RowNumber + 1; + Sequence.SectionIndex = Row.Address.SectionIndex; + if (Sequence.isValid()) + LineTable->appendSequence(Sequence); + Sequence.reset(); + } + Row.postAppend(); +} + +const DWARFDebugLine::LineTable * +DWARFDebugLine::getLineTable(uint64_t Offset) const { + LineTableConstIter Pos = LineTableMap.find(Offset); + if (Pos != LineTableMap.end()) + return &Pos->second; + return nullptr; +} + +Expected<const DWARFDebugLine::LineTable *> DWARFDebugLine::getOrParseLineTable( + DWARFDataExtractor &DebugLineData, uint64_t Offset, const DWARFContext &Ctx, + const DWARFUnit *U, std::function<void(Error)> RecoverableErrorCallback) { + if (!DebugLineData.isValidOffset(Offset)) + return createStringError(errc::invalid_argument, "offset 0x%8.8" PRIx64 + " is not a valid debug line section offset", + Offset); + + std::pair<LineTableIter, bool> Pos = + LineTableMap.insert(LineTableMapTy::value_type(Offset, LineTable())); + LineTable *LT = &Pos.first->second; + if (Pos.second) { + if (Error Err = + LT->parse(DebugLineData, &Offset, Ctx, U, RecoverableErrorCallback)) + return std::move(Err); + return LT; + } + return LT; +} + +Error DWARFDebugLine::LineTable::parse( + DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, + const DWARFContext &Ctx, const DWARFUnit *U, + std::function<void(Error)> RecoverableErrorCallback, raw_ostream *OS) { + const uint64_t DebugLineOffset = *OffsetPtr; + + clear(); + + Error PrologueErr = Prologue.parse(DebugLineData, OffsetPtr, Ctx, U); + + if (OS) { + // The presence of OS signals verbose dumping. + DIDumpOptions DumpOptions; + DumpOptions.Verbose = true; + Prologue.dump(*OS, DumpOptions); + } + + if (PrologueErr) + return PrologueErr; + + const uint64_t EndOffset = + DebugLineOffset + Prologue.TotalLength + Prologue.sizeofTotalLength(); + + // See if we should tell the data extractor the address size. + if (DebugLineData.getAddressSize() == 0) + DebugLineData.setAddressSize(Prologue.getAddressSize()); + else + assert(Prologue.getAddressSize() == 0 || + Prologue.getAddressSize() == DebugLineData.getAddressSize()); + + ParsingState State(this); + + while (*OffsetPtr < EndOffset) { + if (OS) + *OS << format("0x%08.08" PRIx64 ": ", *OffsetPtr); + + uint8_t Opcode = DebugLineData.getU8(OffsetPtr); + + if (OS) + *OS << format("%02.02" PRIx8 " ", Opcode); + + if (Opcode == 0) { + // Extended Opcodes always start with a zero opcode followed by + // a uleb128 length so you can skip ones you don't know about + uint64_t Len = DebugLineData.getULEB128(OffsetPtr); + uint64_t ExtOffset = *OffsetPtr; + + // Tolerate zero-length; assume length is correct and soldier on. + if (Len == 0) { + if (OS) + *OS << "Badly formed extended line op (length 0)\n"; + continue; + } + + uint8_t SubOpcode = DebugLineData.getU8(OffsetPtr); + if (OS) + *OS << LNExtendedString(SubOpcode); + switch (SubOpcode) { + case DW_LNE_end_sequence: + // Set the end_sequence register of the state machine to true and + // append a row to the matrix using the current values of the + // state-machine registers. Then reset the registers to the initial + // values specified above. Every statement program sequence must end + // with a DW_LNE_end_sequence instruction which creates a row whose + // address is that of the byte after the last target machine instruction + // of the sequence. + State.Row.EndSequence = true; + State.appendRowToMatrix(); + if (OS) { + *OS << "\n"; + OS->indent(12); + State.Row.dump(*OS); + } + State.resetRowAndSequence(); + break; + + case DW_LNE_set_address: + // Takes a single relocatable address as an operand. The size of the + // operand is the size appropriate to hold an address on the target + // machine. Set the address register to the value given by the + // relocatable address. All of the other statement program opcodes + // that affect the address register add a delta to it. This instruction + // stores a relocatable value into it instead. + // + // Make sure the extractor knows the address size. If not, infer it + // from the size of the operand. + if (DebugLineData.getAddressSize() == 0) + DebugLineData.setAddressSize(Len - 1); + else if (DebugLineData.getAddressSize() != Len - 1) { + return createStringError(errc::invalid_argument, + "mismatching address size at offset 0x%8.8" PRIx64 + " expected 0x%2.2" PRIx8 " found 0x%2.2" PRIx64, + ExtOffset, DebugLineData.getAddressSize(), + Len - 1); + } + State.Row.Address.Address = DebugLineData.getRelocatedAddress( + OffsetPtr, &State.Row.Address.SectionIndex); + if (OS) + *OS << format(" (0x%16.16" PRIx64 ")", State.Row.Address.Address); + break; + + case DW_LNE_define_file: + // Takes 4 arguments. The first is a null terminated string containing + // a source file name. The second is an unsigned LEB128 number + // representing the directory index of the directory in which the file + // was found. The third is an unsigned LEB128 number representing the + // time of last modification of the file. The fourth is an unsigned + // LEB128 number representing the length in bytes of the file. The time + // and length fields may contain LEB128(0) if the information is not + // available. + // + // The directory index represents an entry in the include_directories + // section of the statement program prologue. The index is LEB128(0) + // if the file was found in the current directory of the compilation, + // LEB128(1) if it was found in the first directory in the + // include_directories section, and so on. The directory index is + // ignored for file names that represent full path names. + // + // The files are numbered, starting at 1, in the order in which they + // appear; the names in the prologue come before names defined by + // the DW_LNE_define_file instruction. These numbers are used in the + // the file register of the state machine. + { + FileNameEntry FileEntry; + const char *Name = DebugLineData.getCStr(OffsetPtr); + FileEntry.Name = + DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name); + FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr); + FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr); + FileEntry.Length = DebugLineData.getULEB128(OffsetPtr); + Prologue.FileNames.push_back(FileEntry); + if (OS) + *OS << " (" << Name << ", dir=" << FileEntry.DirIdx << ", mod_time=" + << format("(0x%16.16" PRIx64 ")", FileEntry.ModTime) + << ", length=" << FileEntry.Length << ")"; + } + break; + + case DW_LNE_set_discriminator: + State.Row.Discriminator = DebugLineData.getULEB128(OffsetPtr); + if (OS) + *OS << " (" << State.Row.Discriminator << ")"; + break; + + default: + if (OS) + *OS << format("Unrecognized extended op 0x%02.02" PRIx8, SubOpcode) + << format(" length %" PRIx64, Len); + // Len doesn't include the zero opcode byte or the length itself, but + // it does include the sub_opcode, so we have to adjust for that. + (*OffsetPtr) += Len - 1; + break; + } + // Make sure the stated and parsed lengths are the same. + // Otherwise we have an unparseable line-number program. + if (*OffsetPtr - ExtOffset != Len) + return createStringError(errc::illegal_byte_sequence, + "unexpected line op length at offset 0x%8.8" PRIx64 + " expected 0x%2.2" PRIx64 " found 0x%2.2" PRIx64, + ExtOffset, Len, *OffsetPtr - ExtOffset); + } else if (Opcode < Prologue.OpcodeBase) { + if (OS) + *OS << LNStandardString(Opcode); + switch (Opcode) { + // Standard Opcodes + case DW_LNS_copy: + // Takes no arguments. Append a row to the matrix using the + // current values of the state-machine registers. + if (OS) { + *OS << "\n"; + OS->indent(12); + State.Row.dump(*OS); + *OS << "\n"; + } + State.appendRowToMatrix(); + break; + + case DW_LNS_advance_pc: + // Takes a single unsigned LEB128 operand, multiplies it by the + // min_inst_length field of the prologue, and adds the + // result to the address register of the state machine. + { + uint64_t AddrOffset = + DebugLineData.getULEB128(OffsetPtr) * Prologue.MinInstLength; + State.Row.Address.Address += AddrOffset; + if (OS) + *OS << " (" << AddrOffset << ")"; + } + break; + + case DW_LNS_advance_line: + // Takes a single signed LEB128 operand and adds that value to + // the line register of the state machine. + State.Row.Line += DebugLineData.getSLEB128(OffsetPtr); + if (OS) + *OS << " (" << State.Row.Line << ")"; + break; + + case DW_LNS_set_file: + // Takes a single unsigned LEB128 operand and stores it in the file + // register of the state machine. + State.Row.File = DebugLineData.getULEB128(OffsetPtr); + if (OS) + *OS << " (" << State.Row.File << ")"; + break; + + case DW_LNS_set_column: + // Takes a single unsigned LEB128 operand and stores it in the + // column register of the state machine. + State.Row.Column = DebugLineData.getULEB128(OffsetPtr); + if (OS) + *OS << " (" << State.Row.Column << ")"; + break; + + case DW_LNS_negate_stmt: + // Takes no arguments. Set the is_stmt register of the state + // machine to the logical negation of its current value. + State.Row.IsStmt = !State.Row.IsStmt; + break; + + case DW_LNS_set_basic_block: + // Takes no arguments. Set the basic_block register of the + // state machine to true + State.Row.BasicBlock = true; + break; + + case DW_LNS_const_add_pc: + // Takes no arguments. Add to the address register of the state + // machine the address increment value corresponding to special + // opcode 255. The motivation for DW_LNS_const_add_pc is this: + // when the statement program needs to advance the address by a + // small amount, it can use a single special opcode, which occupies + // a single byte. When it needs to advance the address by up to + // twice the range of the last special opcode, it can use + // DW_LNS_const_add_pc followed by a special opcode, for a total + // of two bytes. Only if it needs to advance the address by more + // than twice that range will it need to use both DW_LNS_advance_pc + // and a special opcode, requiring three or more bytes. + { + uint8_t AdjustOpcode = 255 - Prologue.OpcodeBase; + uint64_t AddrOffset = + (AdjustOpcode / Prologue.LineRange) * Prologue.MinInstLength; + State.Row.Address.Address += AddrOffset; + if (OS) + *OS + << format(" (0x%16.16" PRIx64 ")", AddrOffset); + } + break; + + case DW_LNS_fixed_advance_pc: + // Takes a single uhalf operand. Add to the address register of + // the state machine the value of the (unencoded) operand. This + // is the only extended opcode that takes an argument that is not + // a variable length number. The motivation for DW_LNS_fixed_advance_pc + // is this: existing assemblers cannot emit DW_LNS_advance_pc or + // special opcodes because they cannot encode LEB128 numbers or + // judge when the computation of a special opcode overflows and + // requires the use of DW_LNS_advance_pc. Such assemblers, however, + // can use DW_LNS_fixed_advance_pc instead, sacrificing compression. + { + uint16_t PCOffset = DebugLineData.getRelocatedValue(2, OffsetPtr); + State.Row.Address.Address += PCOffset; + if (OS) + *OS + << format(" (0x%4.4" PRIx16 ")", PCOffset); + } + break; + + case DW_LNS_set_prologue_end: + // Takes no arguments. Set the prologue_end register of the + // state machine to true + State.Row.PrologueEnd = true; + break; + + case DW_LNS_set_epilogue_begin: + // Takes no arguments. Set the basic_block register of the + // state machine to true + State.Row.EpilogueBegin = true; + break; + + case DW_LNS_set_isa: + // Takes a single unsigned LEB128 operand and stores it in the + // column register of the state machine. + State.Row.Isa = DebugLineData.getULEB128(OffsetPtr); + if (OS) + *OS << " (" << State.Row.Isa << ")"; + break; + + default: + // Handle any unknown standard opcodes here. We know the lengths + // of such opcodes because they are specified in the prologue + // as a multiple of LEB128 operands for each opcode. + { + assert(Opcode - 1U < Prologue.StandardOpcodeLengths.size()); + uint8_t OpcodeLength = Prologue.StandardOpcodeLengths[Opcode - 1]; + for (uint8_t I = 0; I < OpcodeLength; ++I) { + uint64_t Value = DebugLineData.getULEB128(OffsetPtr); + if (OS) + *OS << format("Skipping ULEB128 value: 0x%16.16" PRIx64 ")\n", + Value); + } + } + break; + } + } else { + // Special Opcodes + + // A special opcode value is chosen based on the amount that needs + // to be added to the line and address registers. The maximum line + // increment for a special opcode is the value of the line_base + // field in the header, plus the value of the line_range field, + // minus 1 (line base + line range - 1). If the desired line + // increment is greater than the maximum line increment, a standard + // opcode must be used instead of a special opcode. The "address + // advance" is calculated by dividing the desired address increment + // by the minimum_instruction_length field from the header. The + // special opcode is then calculated using the following formula: + // + // opcode = (desired line increment - line_base) + + // (line_range * address advance) + opcode_base + // + // If the resulting opcode is greater than 255, a standard opcode + // must be used instead. + // + // To decode a special opcode, subtract the opcode_base from the + // opcode itself to give the adjusted opcode. The amount to + // increment the address register is the result of the adjusted + // opcode divided by the line_range multiplied by the + // minimum_instruction_length field from the header. That is: + // + // address increment = (adjusted opcode / line_range) * + // minimum_instruction_length + // + // The amount to increment the line register is the line_base plus + // the result of the adjusted opcode modulo the line_range. That is: + // + // line increment = line_base + (adjusted opcode % line_range) + + uint8_t AdjustOpcode = Opcode - Prologue.OpcodeBase; + uint64_t AddrOffset = + (AdjustOpcode / Prologue.LineRange) * Prologue.MinInstLength; + int32_t LineOffset = + Prologue.LineBase + (AdjustOpcode % Prologue.LineRange); + State.Row.Line += LineOffset; + State.Row.Address.Address += AddrOffset; + + if (OS) { + *OS << "address += " << AddrOffset << ", line += " << LineOffset + << "\n"; + OS->indent(12); + State.Row.dump(*OS); + } + + State.appendRowToMatrix(); + } + if(OS) + *OS << "\n"; + } + + if (!State.Sequence.Empty) + RecoverableErrorCallback( + createStringError(errc::illegal_byte_sequence, + "last sequence in debug line table is not terminated!")); + + // Sort all sequences so that address lookup will work faster. + if (!Sequences.empty()) { + llvm::sort(Sequences, Sequence::orderByHighPC); + // Note: actually, instruction address ranges of sequences should not + // overlap (in shared objects and executables). If they do, the address + // lookup would still work, though, but result would be ambiguous. + // We don't report warning in this case. For example, + // sometimes .so compiled from multiple object files contains a few + // rudimentary sequences for address ranges [0x0, 0xsomething). + } + + return Error::success(); +} + +uint32_t DWARFDebugLine::LineTable::findRowInSeq( + const DWARFDebugLine::Sequence &Seq, + object::SectionedAddress Address) const { + if (!Seq.containsPC(Address)) + return UnknownRowIndex; + assert(Seq.SectionIndex == Address.SectionIndex); + // In some cases, e.g. first instruction in a function, the compiler generates + // two entries, both with the same address. We want the last one. + // + // In general we want a non-empty range: the last row whose address is less + // than or equal to Address. This can be computed as upper_bound - 1. + DWARFDebugLine::Row Row; + Row.Address = Address; + RowIter FirstRow = Rows.begin() + Seq.FirstRowIndex; + RowIter LastRow = Rows.begin() + Seq.LastRowIndex; + assert(FirstRow->Address.Address <= Row.Address.Address && + Row.Address.Address < LastRow[-1].Address.Address); + RowIter RowPos = std::upper_bound(FirstRow + 1, LastRow - 1, Row, + DWARFDebugLine::Row::orderByAddress) - + 1; + assert(Seq.SectionIndex == RowPos->Address.SectionIndex); + return RowPos - Rows.begin(); +} + +uint32_t DWARFDebugLine::LineTable::lookupAddress( + object::SectionedAddress Address) const { + + // Search for relocatable addresses + uint32_t Result = lookupAddressImpl(Address); + + if (Result != UnknownRowIndex || + Address.SectionIndex == object::SectionedAddress::UndefSection) + return Result; + + // Search for absolute addresses + Address.SectionIndex = object::SectionedAddress::UndefSection; + return lookupAddressImpl(Address); +} + +uint32_t DWARFDebugLine::LineTable::lookupAddressImpl( + object::SectionedAddress Address) const { + // First, find an instruction sequence containing the given address. + DWARFDebugLine::Sequence Sequence; + Sequence.SectionIndex = Address.SectionIndex; + Sequence.HighPC = Address.Address; + SequenceIter It = llvm::upper_bound(Sequences, Sequence, + DWARFDebugLine::Sequence::orderByHighPC); + if (It == Sequences.end() || It->SectionIndex != Address.SectionIndex) + return UnknownRowIndex; + return findRowInSeq(*It, Address); +} + +bool DWARFDebugLine::LineTable::lookupAddressRange( + object::SectionedAddress Address, uint64_t Size, + std::vector<uint32_t> &Result) const { + + // Search for relocatable addresses + if (lookupAddressRangeImpl(Address, Size, Result)) + return true; + + if (Address.SectionIndex == object::SectionedAddress::UndefSection) + return false; + + // Search for absolute addresses + Address.SectionIndex = object::SectionedAddress::UndefSection; + return lookupAddressRangeImpl(Address, Size, Result); +} + +bool DWARFDebugLine::LineTable::lookupAddressRangeImpl( + object::SectionedAddress Address, uint64_t Size, + std::vector<uint32_t> &Result) const { + if (Sequences.empty()) + return false; + uint64_t EndAddr = Address.Address + Size; + // First, find an instruction sequence containing the given address. + DWARFDebugLine::Sequence Sequence; + Sequence.SectionIndex = Address.SectionIndex; + Sequence.HighPC = Address.Address; + SequenceIter LastSeq = Sequences.end(); + SequenceIter SeqPos = llvm::upper_bound( + Sequences, Sequence, DWARFDebugLine::Sequence::orderByHighPC); + if (SeqPos == LastSeq || !SeqPos->containsPC(Address)) + return false; + + SequenceIter StartPos = SeqPos; + + // Add the rows from the first sequence to the vector, starting with the + // index we just calculated + + while (SeqPos != LastSeq && SeqPos->LowPC < EndAddr) { + const DWARFDebugLine::Sequence &CurSeq = *SeqPos; + // For the first sequence, we need to find which row in the sequence is the + // first in our range. + uint32_t FirstRowIndex = CurSeq.FirstRowIndex; + if (SeqPos == StartPos) + FirstRowIndex = findRowInSeq(CurSeq, Address); + + // Figure out the last row in the range. + uint32_t LastRowIndex = + findRowInSeq(CurSeq, {EndAddr - 1, Address.SectionIndex}); + if (LastRowIndex == UnknownRowIndex) + LastRowIndex = CurSeq.LastRowIndex - 1; + + assert(FirstRowIndex != UnknownRowIndex); + assert(LastRowIndex != UnknownRowIndex); + + for (uint32_t I = FirstRowIndex; I <= LastRowIndex; ++I) { + Result.push_back(I); + } + + ++SeqPos; + } + + return true; +} + +Optional<StringRef> DWARFDebugLine::LineTable::getSourceByIndex(uint64_t FileIndex, + FileLineInfoKind Kind) const { + if (Kind == FileLineInfoKind::None || !Prologue.hasFileAtIndex(FileIndex)) + return None; + const FileNameEntry &Entry = Prologue.getFileNameEntry(FileIndex); + if (Optional<const char *> source = Entry.Source.getAsCString()) + return StringRef(*source); + return None; +} + +static bool isPathAbsoluteOnWindowsOrPosix(const Twine &Path) { + // Debug info can contain paths from any OS, not necessarily + // an OS we're currently running on. Moreover different compilation units can + // be compiled on different operating systems and linked together later. + return sys::path::is_absolute(Path, sys::path::Style::posix) || + sys::path::is_absolute(Path, sys::path::Style::windows); +} + +bool DWARFDebugLine::Prologue::getFileNameByIndex( + uint64_t FileIndex, StringRef CompDir, FileLineInfoKind Kind, + std::string &Result, sys::path::Style Style) const { + if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex)) + return false; + const FileNameEntry &Entry = getFileNameEntry(FileIndex); + StringRef FileName = Entry.Name.getAsCString().getValue(); + if (Kind != FileLineInfoKind::AbsoluteFilePath || + isPathAbsoluteOnWindowsOrPosix(FileName)) { + Result = FileName; + return true; + } + + SmallString<16> FilePath; + StringRef IncludeDir; + // Be defensive about the contents of Entry. + if (getVersion() >= 5) { + if (Entry.DirIdx < IncludeDirectories.size()) + IncludeDir = IncludeDirectories[Entry.DirIdx].getAsCString().getValue(); + } else { + if (0 < Entry.DirIdx && Entry.DirIdx <= IncludeDirectories.size()) + IncludeDir = + IncludeDirectories[Entry.DirIdx - 1].getAsCString().getValue(); + + // We may still need to append compilation directory of compile unit. + // We know that FileName is not absolute, the only way to have an + // absolute path at this point would be if IncludeDir is absolute. + if (!CompDir.empty() && !isPathAbsoluteOnWindowsOrPosix(IncludeDir)) + sys::path::append(FilePath, Style, CompDir); + } + + // sys::path::append skips empty strings. + sys::path::append(FilePath, Style, IncludeDir, FileName); + Result = FilePath.str(); + return true; +} + +bool DWARFDebugLine::LineTable::getFileLineInfoForAddress( + object::SectionedAddress Address, const char *CompDir, + FileLineInfoKind Kind, DILineInfo &Result) const { + // Get the index of row we're looking for in the line table. + uint32_t RowIndex = lookupAddress(Address); + if (RowIndex == -1U) + return false; + // Take file number and line/column from the row. + const auto &Row = Rows[RowIndex]; + if (!getFileNameByIndex(Row.File, CompDir, Kind, Result.FileName)) + return false; + Result.Line = Row.Line; + Result.Column = Row.Column; + Result.Discriminator = Row.Discriminator; + Result.Source = getSourceByIndex(Row.File, Kind); + return true; +} + +// We want to supply the Unit associated with a .debug_line[.dwo] table when +// we dump it, if possible, but still dump the table even if there isn't a Unit. +// Therefore, collect up handles on all the Units that point into the +// line-table section. +static DWARFDebugLine::SectionParser::LineToUnitMap +buildLineToUnitMap(DWARFDebugLine::SectionParser::cu_range CUs, + DWARFDebugLine::SectionParser::tu_range TUs) { + DWARFDebugLine::SectionParser::LineToUnitMap LineToUnit; + for (const auto &CU : CUs) + if (auto CUDIE = CU->getUnitDIE()) + if (auto StmtOffset = toSectionOffset(CUDIE.find(DW_AT_stmt_list))) + LineToUnit.insert(std::make_pair(*StmtOffset, &*CU)); + for (const auto &TU : TUs) + if (auto TUDIE = TU->getUnitDIE()) + if (auto StmtOffset = toSectionOffset(TUDIE.find(DW_AT_stmt_list))) + LineToUnit.insert(std::make_pair(*StmtOffset, &*TU)); + return LineToUnit; +} + +DWARFDebugLine::SectionParser::SectionParser(DWARFDataExtractor &Data, + const DWARFContext &C, + cu_range CUs, tu_range TUs) + : DebugLineData(Data), Context(C) { + LineToUnit = buildLineToUnitMap(CUs, TUs); + if (!DebugLineData.isValidOffset(Offset)) + Done = true; +} + +bool DWARFDebugLine::Prologue::totalLengthIsValid() const { + return TotalLength == dwarf::DW_LENGTH_DWARF64 || + TotalLength < dwarf::DW_LENGTH_lo_reserved; +} + +DWARFDebugLine::LineTable DWARFDebugLine::SectionParser::parseNext( + function_ref<void(Error)> RecoverableErrorCallback, + function_ref<void(Error)> UnrecoverableErrorCallback, raw_ostream *OS) { + assert(DebugLineData.isValidOffset(Offset) && + "parsing should have terminated"); + DWARFUnit *U = prepareToParse(Offset); + uint64_t OldOffset = Offset; + LineTable LT; + if (Error Err = LT.parse(DebugLineData, &Offset, Context, U, + RecoverableErrorCallback, OS)) + UnrecoverableErrorCallback(std::move(Err)); + moveToNextTable(OldOffset, LT.Prologue); + return LT; +} + +void DWARFDebugLine::SectionParser::skip( + function_ref<void(Error)> ErrorCallback) { + assert(DebugLineData.isValidOffset(Offset) && + "parsing should have terminated"); + DWARFUnit *U = prepareToParse(Offset); + uint64_t OldOffset = Offset; + LineTable LT; + if (Error Err = LT.Prologue.parse(DebugLineData, &Offset, Context, U)) + ErrorCallback(std::move(Err)); + moveToNextTable(OldOffset, LT.Prologue); +} + +DWARFUnit *DWARFDebugLine::SectionParser::prepareToParse(uint64_t Offset) { + DWARFUnit *U = nullptr; + auto It = LineToUnit.find(Offset); + if (It != LineToUnit.end()) + U = It->second; + DebugLineData.setAddressSize(U ? U->getAddressByteSize() : 0); + return U; +} + +void DWARFDebugLine::SectionParser::moveToNextTable(uint64_t OldOffset, + const Prologue &P) { + // If the length field is not valid, we don't know where the next table is, so + // cannot continue to parse. Mark the parser as done, and leave the Offset + // value as it currently is. This will be the end of the bad length field. + if (!P.totalLengthIsValid()) { + Done = true; + return; + } + + Offset = OldOffset + P.TotalLength + P.sizeofTotalLength(); + if (!DebugLineData.isValidOffset(Offset)) { + Done = true; + } +} |