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llvm-for-llvmta/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

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2022-04-25 10:02:23 +02:00
//===- 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/FormatVariadic.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 anonymous namespace
static bool versionIsSupported(uint16_t Version) {
return Version >= 2 && Version <= 5;
}
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();
}
Optional<uint64_t> DWARFDebugLine::Prologue::getLastValidFileIndex() const {
if (FileNames.empty())
return None;
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.size() - 1;
return 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 {
if (!totalLengthIsValid())
return;
int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(FormParams.Format);
OS << "Line table prologue:\n"
<< format(" total_length: 0x%0*" PRIx64 "\n", OffsetDumpWidth,
TotalLength)
<< " format: " << dwarf::FormatString(FormParams.Format) << "\n"
<< format(" version: %u\n", getVersion());
if (!versionIsSupported(getVersion()))
return;
if (getVersion() >= 5)
OS << format(" address_size: %u\n", getAddressSize())
<< format(" seg_select_size: %u\n", SegSelectorSize);
OS << format(" prologue_length: 0x%0*" PRIx64 "\n", OffsetDumpWidth,
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 << formatv("standard_opcode_lengths[{0}] = {1}\n",
static_cast<dwarf::LineNumberOps>(I + 1),
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 Error
parseV2DirFileTables(const DWARFDataExtractor &DebugLineData,
uint64_t *OffsetPtr,
DWARFDebugLine::ContentTypeTracker &ContentTypes,
std::vector<DWARFFormValue> &IncludeDirectories,
std::vector<DWARFDebugLine::FileNameEntry> &FileNames) {
while (true) {
Error Err = Error::success();
StringRef S = DebugLineData.getCStrRef(OffsetPtr, &Err);
if (Err) {
consumeError(std::move(Err));
return createStringError(errc::invalid_argument,
"include directories table was not null "
"terminated before the end of the prologue");
}
if (S.empty())
break;
DWARFFormValue Dir =
DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, S.data());
IncludeDirectories.push_back(Dir);
}
ContentTypes.HasModTime = true;
ContentTypes.HasLength = true;
while (true) {
Error Err = Error::success();
StringRef Name = DebugLineData.getCStrRef(OffsetPtr, &Err);
if (!Err && Name.empty())
break;
DWARFDebugLine::FileNameEntry FileEntry;
FileEntry.Name =
DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name.data());
FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr, &Err);
FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr, &Err);
FileEntry.Length = DebugLineData.getULEB128(OffsetPtr, &Err);
if (Err) {
consumeError(std::move(Err));
return createStringError(
errc::invalid_argument,
"file names table was not null terminated before "
"the end of the prologue");
}
FileNames.push_back(FileEntry);
}
return Error::success();
}
// 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,
DWARFDebugLine::ContentTypeTracker *ContentTypes) {
Error Err = Error::success();
ContentDescriptors Descriptors;
int FormatCount = DebugLineData.getU8(OffsetPtr, &Err);
bool HasPath = false;
for (int I = 0; I != FormatCount && !Err; ++I) {
ContentDescriptor Descriptor;
Descriptor.Type =
dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr, &Err));
Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr, &Err));
if (Descriptor.Type == dwarf::DW_LNCT_path)
HasPath = true;
if (ContentTypes)
ContentTypes->trackContentType(Descriptor.Type);
Descriptors.push_back(Descriptor);
}
if (Err)
return createStringError(errc::invalid_argument,
"failed to parse entry content descriptors: %s",
toString(std::move(Err)).c_str());
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, 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, nullptr);
if (!DirDescriptors)
return DirDescriptors.takeError();
// Get the directory entries, according to the format described above.
uint64_t DirEntryCount = DebugLineData.getULEB128(OffsetPtr);
for (uint64_t I = 0; I != DirEntryCount; ++I) {
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, &ContentTypes);
if (!FileDescriptors)
return FileDescriptors.takeError();
// Get the file entries, according to the format described above.
uint64_t FileEntryCount = DebugLineData.getULEB128(OffsetPtr);
for (uint64_t I = 0; I != FileEntryCount; ++I) {
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();
}
uint64_t DWARFDebugLine::Prologue::getLength() const {
uint64_t Length = PrologueLength + sizeofTotalLength() +
sizeof(getVersion()) + sizeofPrologueLength();
if (getVersion() >= 5)
Length += 2; // Address + Segment selector sizes.
return Length;
}
Error DWARFDebugLine::Prologue::parse(
DWARFDataExtractor DebugLineData, uint64_t *OffsetPtr,
function_ref<void(Error)> RecoverableErrorHandler, const DWARFContext &Ctx,
const DWARFUnit *U) {
const uint64_t PrologueOffset = *OffsetPtr;
clear();
DataExtractor::Cursor Cursor(*OffsetPtr);
std::tie(TotalLength, FormParams.Format) =
DebugLineData.getInitialLength(Cursor);
DebugLineData =
DWARFDataExtractor(DebugLineData, Cursor.tell() + TotalLength);
FormParams.Version = DebugLineData.getU16(Cursor);
if (Cursor && !versionIsSupported(getVersion())) {
// Treat this error as unrecoverable - we cannot be sure what any of
// the data represents including the length field, so cannot skip it or make
// any reasonable assumptions.
*OffsetPtr = Cursor.tell();
return createStringError(
errc::not_supported,
"parsing line table prologue at offset 0x%8.8" PRIx64
": unsupported version %" PRIu16,
PrologueOffset, getVersion());
}
if (getVersion() >= 5) {
FormParams.AddrSize = DebugLineData.getU8(Cursor);
assert((!Cursor || DebugLineData.getAddressSize() == 0 ||
DebugLineData.getAddressSize() == getAddressSize()) &&
"Line table header and data extractor disagree");
SegSelectorSize = DebugLineData.getU8(Cursor);
}
PrologueLength =
DebugLineData.getRelocatedValue(Cursor, sizeofPrologueLength());
const uint64_t EndPrologueOffset = PrologueLength + Cursor.tell();
DebugLineData = DWARFDataExtractor(DebugLineData, EndPrologueOffset);
MinInstLength = DebugLineData.getU8(Cursor);
if (getVersion() >= 4)
MaxOpsPerInst = DebugLineData.getU8(Cursor);
DefaultIsStmt = DebugLineData.getU8(Cursor);
LineBase = DebugLineData.getU8(Cursor);
LineRange = DebugLineData.getU8(Cursor);
OpcodeBase = DebugLineData.getU8(Cursor);
if (Cursor && OpcodeBase == 0) {
// If the opcode base is 0, we cannot read the standard opcode lengths (of
// which there are supposed to be one fewer than the opcode base). Assume
// there are no standard opcodes and continue parsing.
RecoverableErrorHandler(createStringError(
errc::invalid_argument,
"parsing line table prologue at offset 0x%8.8" PRIx64
" found opcode base of 0. Assuming no standard opcodes",
PrologueOffset));
} else if (Cursor) {
StandardOpcodeLengths.reserve(OpcodeBase - 1);
for (uint32_t I = 1; I < OpcodeBase; ++I) {
uint8_t OpLen = DebugLineData.getU8(Cursor);
StandardOpcodeLengths.push_back(OpLen);
}
}
*OffsetPtr = Cursor.tell();
// A corrupt file name or directory table does not prevent interpretation of
// the main line program, so check the cursor state now so that its errors can
// be handled separately.
if (!Cursor)
return createStringError(
errc::invalid_argument,
"parsing line table prologue at offset 0x%8.8" PRIx64 ": %s",
PrologueOffset, toString(Cursor.takeError()).c_str());
Error E =
getVersion() >= 5
? parseV5DirFileTables(DebugLineData, OffsetPtr, FormParams, Ctx, U,
ContentTypes, IncludeDirectories, FileNames)
: parseV2DirFileTables(DebugLineData, OffsetPtr, ContentTypes,
IncludeDirectories, FileNames);
if (E) {
RecoverableErrorHandler(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)));
return Error::success();
}
assert(*OffsetPtr <= EndPrologueOffset);
if (*OffsetPtr != EndPrologueOffset) {
RecoverableErrorHandler(createStringError(
errc::invalid_argument,
"unknown data in line table prologue at offset 0x%8.8" PRIx64
": parsing ended (at offset 0x%8.8" PRIx64
") before reaching the prologue end at offset 0x%8.8" PRIx64,
PrologueOffset, *OffsetPtr, EndPrologueOffset));
}
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, unsigned Indent) {
OS.indent(Indent)
<< "Address Line Column File ISA Discriminator Flags\n";
OS.indent(Indent)
<< "------------------ ------ ------ ------ --- ------------- "
"-------------\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);
if (!Rows.empty()) {
OS << '\n';
Row::dumpTableHeader(OS, 0);
for (const Row &R : Rows) {
R.dump(OS);
}
}
// Terminate the table with a final blank line to clearly delineate it from
// later dumps.
OS << '\n';
}
void DWARFDebugLine::LineTable::clear() {
Prologue.clear();
Rows.clear();
Sequences.clear();
}
DWARFDebugLine::ParsingState::ParsingState(
struct LineTable *LT, uint64_t TableOffset,
function_ref<void(Error)> ErrorHandler)
: LineTable(LT), LineTableOffset(TableOffset), ErrorHandler(ErrorHandler) {
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, function_ref<void(Error)> RecoverableErrorHandler) {
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, RecoverableErrorHandler))
return std::move(Err);
return LT;
}
return LT;
}
static StringRef getOpcodeName(uint8_t Opcode, uint8_t OpcodeBase) {
assert(Opcode != 0);
if (Opcode < OpcodeBase)
return LNStandardString(Opcode);
return "special";
}
uint64_t DWARFDebugLine::ParsingState::advanceAddr(uint64_t OperationAdvance,
uint8_t Opcode,
uint64_t OpcodeOffset) {
StringRef OpcodeName = getOpcodeName(Opcode, LineTable->Prologue.OpcodeBase);
// For versions less than 4, the MaxOpsPerInst member is set to 0, as the
// maximum_operations_per_instruction field wasn't introduced until DWARFv4.
// Don't warn about bad values in this situation.
if (ReportAdvanceAddrProblem && LineTable->Prologue.getVersion() >= 4 &&
LineTable->Prologue.MaxOpsPerInst != 1)
ErrorHandler(createStringError(
errc::not_supported,
"line table program at offset 0x%8.8" PRIx64
" contains a %s opcode at offset 0x%8.8" PRIx64
", but the prologue maximum_operations_per_instruction value is %" PRId8
", which is unsupported. Assuming a value of 1 instead",
LineTableOffset, OpcodeName.data(), OpcodeOffset,
LineTable->Prologue.MaxOpsPerInst));
if (ReportAdvanceAddrProblem && LineTable->Prologue.MinInstLength == 0)
ErrorHandler(
createStringError(errc::invalid_argument,
"line table program at offset 0x%8.8" PRIx64
" contains a %s opcode at offset 0x%8.8" PRIx64
", but the prologue minimum_instruction_length value "
"is 0, which prevents any address advancing",
LineTableOffset, OpcodeName.data(), OpcodeOffset));
ReportAdvanceAddrProblem = false;
uint64_t AddrOffset = OperationAdvance * LineTable->Prologue.MinInstLength;
Row.Address.Address += AddrOffset;
return AddrOffset;
}
DWARFDebugLine::ParsingState::AddrAndAdjustedOpcode
DWARFDebugLine::ParsingState::advanceAddrForOpcode(uint8_t Opcode,
uint64_t OpcodeOffset) {
assert(Opcode == DW_LNS_const_add_pc ||
Opcode >= LineTable->Prologue.OpcodeBase);
if (ReportBadLineRange && LineTable->Prologue.LineRange == 0) {
StringRef OpcodeName =
getOpcodeName(Opcode, LineTable->Prologue.OpcodeBase);
ErrorHandler(
createStringError(errc::not_supported,
"line table program at offset 0x%8.8" PRIx64
" contains a %s opcode at offset 0x%8.8" PRIx64
", but the prologue line_range value is 0. The "
"address and line will not be adjusted",
LineTableOffset, OpcodeName.data(), OpcodeOffset));
ReportBadLineRange = false;
}
uint8_t OpcodeValue = Opcode;
if (Opcode == DW_LNS_const_add_pc)
OpcodeValue = 255;
uint8_t AdjustedOpcode = OpcodeValue - LineTable->Prologue.OpcodeBase;
uint64_t OperationAdvance =
LineTable->Prologue.LineRange != 0
? AdjustedOpcode / LineTable->Prologue.LineRange
: 0;
uint64_t AddrOffset = advanceAddr(OperationAdvance, Opcode, OpcodeOffset);
return {AddrOffset, AdjustedOpcode};
}
DWARFDebugLine::ParsingState::AddrAndLineDelta
DWARFDebugLine::ParsingState::handleSpecialOpcode(uint8_t Opcode,
uint64_t OpcodeOffset) {
// 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)
DWARFDebugLine::ParsingState::AddrAndAdjustedOpcode AddrAdvanceResult =
advanceAddrForOpcode(Opcode, OpcodeOffset);
int32_t LineOffset = 0;
if (LineTable->Prologue.LineRange != 0)
LineOffset =
LineTable->Prologue.LineBase +
(AddrAdvanceResult.AdjustedOpcode % LineTable->Prologue.LineRange);
Row.Line += LineOffset;
return {AddrAdvanceResult.AddrDelta, LineOffset};
}
/// Parse a ULEB128 using the specified \p Cursor. \returns the parsed value on
/// success, or None if \p Cursor is in a failing state.
template <typename T>
static Optional<T> parseULEB128(DWARFDataExtractor &Data,
DataExtractor::Cursor &Cursor) {
T Value = Data.getULEB128(Cursor);
if (Cursor)
return Value;
return None;
}
Error DWARFDebugLine::LineTable::parse(
DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr,
const DWARFContext &Ctx, const DWARFUnit *U,
function_ref<void(Error)> RecoverableErrorHandler, raw_ostream *OS,
bool Verbose) {
assert((OS || !Verbose) && "cannot have verbose output without stream");
const uint64_t DebugLineOffset = *OffsetPtr;
clear();
Error PrologueErr =
Prologue.parse(DebugLineData, OffsetPtr, RecoverableErrorHandler, Ctx, U);
if (OS) {
DIDumpOptions DumpOptions;
DumpOptions.Verbose = Verbose;
Prologue.dump(*OS, DumpOptions);
}
if (PrologueErr) {
// Ensure there is a blank line after the prologue to clearly delineate it
// from later dumps.
if (OS)
*OS << "\n";
return PrologueErr;
}
uint64_t ProgramLength = Prologue.TotalLength + Prologue.sizeofTotalLength();
if (!DebugLineData.isValidOffsetForDataOfSize(DebugLineOffset,
ProgramLength)) {
assert(DebugLineData.size() > DebugLineOffset &&
"prologue parsing should handle invalid offset");
uint64_t BytesRemaining = DebugLineData.size() - DebugLineOffset;
RecoverableErrorHandler(
createStringError(errc::invalid_argument,
"line table program with offset 0x%8.8" PRIx64
" has length 0x%8.8" PRIx64 " but only 0x%8.8" PRIx64
" bytes are available",
DebugLineOffset, ProgramLength, BytesRemaining));
// Continue by capping the length at the number of remaining bytes.
ProgramLength = BytesRemaining;
}
// Create a DataExtractor which can only see the data up to the end of the
// table, to prevent reading past the end.
const uint64_t EndOffset = DebugLineOffset + ProgramLength;
DWARFDataExtractor TableData(DebugLineData, EndOffset);
// See if we should tell the data extractor the address size.
if (TableData.getAddressSize() == 0)
TableData.setAddressSize(Prologue.getAddressSize());
else
assert(Prologue.getAddressSize() == 0 ||
Prologue.getAddressSize() == TableData.getAddressSize());
ParsingState State(this, DebugLineOffset, RecoverableErrorHandler);
*OffsetPtr = DebugLineOffset + Prologue.getLength();
if (OS && *OffsetPtr < EndOffset) {
*OS << '\n';
Row::dumpTableHeader(*OS, /*Indent=*/Verbose ? 12 : 0);
}
bool TombstonedAddress = false;
auto EmitRow = [&] {
if (!TombstonedAddress) {
if (Verbose) {
*OS << "\n";
OS->indent(12);
}
if (OS)
State.Row.dump(*OS);
State.appendRowToMatrix();
}
};
while (*OffsetPtr < EndOffset) {
DataExtractor::Cursor Cursor(*OffsetPtr);
if (Verbose)
*OS << format("0x%08.08" PRIx64 ": ", *OffsetPtr);
uint64_t OpcodeOffset = *OffsetPtr;
uint8_t Opcode = TableData.getU8(Cursor);
size_t RowCount = Rows.size();
if (Cursor && Verbose)
*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 = TableData.getULEB128(Cursor);
uint64_t ExtOffset = Cursor.tell();
// Tolerate zero-length; assume length is correct and soldier on.
if (Len == 0) {
if (Cursor && Verbose)
*OS << "Badly formed extended line op (length 0)\n";
if (!Cursor) {
if (Verbose)
*OS << "\n";
RecoverableErrorHandler(Cursor.takeError());
}
*OffsetPtr = Cursor.tell();
continue;
}
uint8_t SubOpcode = TableData.getU8(Cursor);
// OperandOffset will be the same as ExtOffset, if it was not possible to
// read the SubOpcode.
uint64_t OperandOffset = Cursor.tell();
if (Verbose)
*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;
// No need to test the Cursor is valid here, since it must be to get
// into this code path - if it were invalid, the default case would be
// followed.
EmitRow();
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.
{
uint8_t ExtractorAddressSize = TableData.getAddressSize();
uint64_t OpcodeAddressSize = Len - 1;
if (ExtractorAddressSize != OpcodeAddressSize &&
ExtractorAddressSize != 0)
RecoverableErrorHandler(createStringError(
errc::invalid_argument,
"mismatching address size at offset 0x%8.8" PRIx64
" expected 0x%2.2" PRIx8 " found 0x%2.2" PRIx64,
ExtOffset, ExtractorAddressSize, Len - 1));
// Assume that the line table is correct and temporarily override the
// address size. If the size is unsupported, give up trying to read
// the address and continue to the next opcode.
if (OpcodeAddressSize != 1 && OpcodeAddressSize != 2 &&
OpcodeAddressSize != 4 && OpcodeAddressSize != 8) {
RecoverableErrorHandler(createStringError(
errc::invalid_argument,
"address size 0x%2.2" PRIx64
" of DW_LNE_set_address opcode at offset 0x%8.8" PRIx64
" is unsupported",
OpcodeAddressSize, ExtOffset));
TableData.skip(Cursor, OpcodeAddressSize);
} else {
TableData.setAddressSize(OpcodeAddressSize);
State.Row.Address.Address = TableData.getRelocatedAddress(
Cursor, &State.Row.Address.SectionIndex);
uint64_t Tombstone =
dwarf::computeTombstoneAddress(OpcodeAddressSize);
TombstonedAddress = State.Row.Address.Address == Tombstone;
// Restore the address size if the extractor already had it.
if (ExtractorAddressSize != 0)
TableData.setAddressSize(ExtractorAddressSize);
}
if (Cursor && Verbose) {
*OS << " (";
DWARFFormValue::dumpAddress(*OS, OpcodeAddressSize, State.Row.Address.Address);
*OS << ')';
}
}
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 = TableData.getCStr(Cursor);
FileEntry.Name =
DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name);
FileEntry.DirIdx = TableData.getULEB128(Cursor);
FileEntry.ModTime = TableData.getULEB128(Cursor);
FileEntry.Length = TableData.getULEB128(Cursor);
Prologue.FileNames.push_back(FileEntry);
if (Cursor && Verbose)
*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 = TableData.getULEB128(Cursor);
if (Cursor && Verbose)
*OS << " (" << State.Row.Discriminator << ")";
break;
default:
if (Cursor && Verbose)
*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.
TableData.skip(Cursor, Len - 1);
break;
}
// Make sure the length as recorded in the table and the standard length
// for the opcode match. If they don't, continue from the end as claimed
// by the table. Similarly, continue from the claimed end in the event of
// a parsing error.
uint64_t End = ExtOffset + Len;
if (Cursor && Cursor.tell() != End)
RecoverableErrorHandler(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, Cursor.tell() - ExtOffset));
if (!Cursor && Verbose) {
DWARFDataExtractor::Cursor ByteCursor(OperandOffset);
uint8_t Byte = TableData.getU8(ByteCursor);
if (ByteCursor) {
*OS << " (<parsing error>";
do {
*OS << format(" %2.2" PRIx8, Byte);
Byte = TableData.getU8(ByteCursor);
} while (ByteCursor);
*OS << ")";
}
// The only parse failure in this case should be if the end was reached.
// In that case, throw away the error, as the main Cursor's error will
// be sufficient.
consumeError(ByteCursor.takeError());
}
*OffsetPtr = End;
} else if (Opcode < Prologue.OpcodeBase) {
if (Verbose)
*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.
EmitRow();
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.
if (Optional<uint64_t> Operand =
parseULEB128<uint64_t>(TableData, Cursor)) {
uint64_t AddrOffset =
State.advanceAddr(*Operand, Opcode, OpcodeOffset);
if (Verbose)
*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.
{
int64_t LineDelta = TableData.getSLEB128(Cursor);
if (Cursor) {
State.Row.Line += LineDelta;
if (Verbose)
*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.
if (Optional<uint16_t> File =
parseULEB128<uint16_t>(TableData, Cursor)) {
State.Row.File = *File;
if (Verbose)
*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.
if (Optional<uint16_t> Column =
parseULEB128<uint16_t>(TableData, Cursor)) {
State.Row.Column = *Column;
if (Verbose)
*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.
{
uint64_t AddrOffset =
State.advanceAddrForOpcode(Opcode, OpcodeOffset).AddrDelta;
if (Verbose)
*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 =
TableData.getRelocatedValue(Cursor, 2);
if (Cursor) {
State.Row.Address.Address += PCOffset;
if (Verbose)
*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
// ISA register of the state machine.
if (Optional<uint8_t> Isa = parseULEB128<uint8_t>(TableData, Cursor)) {
State.Row.Isa = *Isa;
if (Verbose)
*OS << " (" << (uint64_t)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());
if (Verbose)
*OS << "Unrecognized standard opcode";
uint8_t OpcodeLength = Prologue.StandardOpcodeLengths[Opcode - 1];
std::vector<uint64_t> Operands;
for (uint8_t I = 0; I < OpcodeLength; ++I) {
if (Optional<uint64_t> Value =
parseULEB128<uint64_t>(TableData, Cursor))
Operands.push_back(*Value);
else
break;
}
if (Verbose && !Operands.empty()) {
*OS << " (operands: ";
bool First = true;
for (uint64_t Value : Operands) {
if (!First)
*OS << ", ";
First = false;
*OS << format("0x%16.16" PRIx64, Value);
}
if (Verbose)
*OS << ')';
}
}
break;
}
*OffsetPtr = Cursor.tell();
} else {
// Special Opcodes.
ParsingState::AddrAndLineDelta Delta =
State.handleSpecialOpcode(Opcode, OpcodeOffset);
if (Verbose)
*OS << "address += " << Delta.Address << ", line += " << Delta.Line;
EmitRow();
*OffsetPtr = Cursor.tell();
}
// When a row is added to the matrix, it is also dumped, which includes a
// new line already, so don't add an extra one.
if (Verbose && Rows.size() == RowCount)
*OS << "\n";
// Most parse failures other than when parsing extended opcodes are due to
// failures to read ULEBs. Bail out of parsing, since we don't know where to
// continue reading from as there is no stated length for such byte
// sequences. Print the final trailing new line if needed before doing so.
if (!Cursor && Opcode != 0) {
if (Verbose)
*OS << "\n";
return Cursor.takeError();
}
if (!Cursor)
RecoverableErrorHandler(Cursor.takeError());
}
if (!State.Sequence.Empty)
RecoverableErrorHandler(createStringError(
errc::illegal_byte_sequence,
"last sequence in debug line table at offset 0x%8.8" PRIx64
" is not terminated",
DebugLineOffset));
// 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).
}
// Terminate the table with a final blank line to clearly delineate it from
// later dumps.
if (OS)
*OS << "\n";
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);
Optional<const char *> Name = Entry.Name.getAsCString();
if (!Name)
return false;
StringRef FileName = *Name;
if (Kind == FileLineInfoKind::RawValue ||
isPathAbsoluteOnWindowsOrPosix(FileName)) {
Result = std::string(FileName);
return true;
}
if (Kind == FileLineInfoKind::BaseNameOnly) {
Result = std::string(llvm::sys::path::filename(FileName));
return true;
}
SmallString<16> FilePath;
StringRef IncludeDir;
// Be defensive about the contents of Entry.
if (getVersion() >= 5) {
// DirIdx 0 is the compilation directory, so don't include it for
// relative names.
if ((Entry.DirIdx != 0 || Kind != FileLineInfoKind::RelativeFilePath) &&
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();
}
// For absolute paths only, include the 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 (Kind == FileLineInfoKind::AbsoluteFilePath && !CompDir.empty() &&
!isPathAbsoluteOnWindowsOrPosix(IncludeDir))
sys::path::append(FilePath, Style, CompDir);
assert((Kind == FileLineInfoKind::AbsoluteFilePath ||
Kind == FileLineInfoKind::RelativeFilePath) &&
"invalid FileLineInfo Kind");
// sys::path::append skips empty strings.
sys::path::append(FilePath, Style, IncludeDir, FileName);
Result = std::string(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(DWARFUnitVector::iterator_range Units) {
DWARFDebugLine::SectionParser::LineToUnitMap LineToUnit;
for (const auto &U : Units)
if (auto CUDIE = U->getUnitDIE())
if (auto StmtOffset = toSectionOffset(CUDIE.find(DW_AT_stmt_list)))
LineToUnit.insert(std::make_pair(*StmtOffset, &*U));
return LineToUnit;
}
DWARFDebugLine::SectionParser::SectionParser(
DWARFDataExtractor &Data, const DWARFContext &C,
DWARFUnitVector::iterator_range Units)
: DebugLineData(Data), Context(C) {
LineToUnit = buildLineToUnitMap(Units);
if (!DebugLineData.isValidOffset(Offset))
Done = true;
}
bool DWARFDebugLine::Prologue::totalLengthIsValid() const {
return TotalLength != 0u;
}
DWARFDebugLine::LineTable DWARFDebugLine::SectionParser::parseNext(
function_ref<void(Error)> RecoverableErrorHandler,
function_ref<void(Error)> UnrecoverableErrorHandler, raw_ostream *OS,
bool Verbose) {
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,
RecoverableErrorHandler, OS, Verbose))
UnrecoverableErrorHandler(std::move(Err));
moveToNextTable(OldOffset, LT.Prologue);
return LT;
}
void DWARFDebugLine::SectionParser::skip(
function_ref<void(Error)> RecoverableErrorHandler,
function_ref<void(Error)> UnrecoverableErrorHandler) {
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,
RecoverableErrorHandler, Context, U))
UnrecoverableErrorHandler(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;
}
}