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llvm-capstone/bolt/lib/Core/DebugData.cpp
Rafael Auler a34c753fe7 Rebase: [NFC] Refactor sources to be buildable in shared mode 
Summary:
Moves source files into separate components, and make explicit
component dependency on each other, so LLVM build system knows how to
build BOLT in BUILD_SHARED_LIBS=ON.

Please use the -c merge.renamelimit=230 git option when rebasing your
work on top of this change.

To achieve this, we create a new library to hold core IR files (most
classes beginning with Binary in their names), a new library to hold
Utils, some command line options shared across both RewriteInstance
and core IR files, a new library called Rewrite to hold most classes
concerned with running top-level functions coordinating the binary
rewriting process, and a new library called Profile to hold classes
dealing with profile reading and writing.

To remove the dependency from BinaryContext into X86-specific classes,
we do some refactoring on the BinaryContext constructor to receive a
reference to the specific backend directly from RewriteInstance. Then,
the dependency on X86 or AArch64-specific classes is transfered to the
Rewrite library. We can't have the Core library depend on targets
because targets depend on Core (which would create a cycle).

Files implementing the entry point of a tool are transferred to the
tools/ folder. All header files are transferred to the include/
folder. The src/ folder was renamed to lib/.

(cherry picked from FBD32746834)
2021-10-08 11:47:10 -07:00

792 lines
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//===- DebugData.cpp - Representation and writing of debugging information. ==//
//
// 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 "bolt/Core/DebugData.h"
#include "bolt/Core/BinaryBasicBlock.h"
#include "bolt/Core/BinaryFunction.h"
#include "bolt/Utils/Utils.h"
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/LEB128.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <limits>
#undef DEBUG_TYPE
#define DEBUG_TYPE "bolt-debug-info"
namespace opts {
extern llvm::cl::opt<unsigned> Verbosity;
}
namespace llvm {
namespace bolt {
const DebugLineTableRowRef DebugLineTableRowRef::NULL_ROW{0, 0};
namespace {
// Writes address ranges to Writer as pairs of 64-bit (address, size).
// If RelativeRange is true, assumes the address range to be written must be of
// the form (begin address, range size), otherwise (begin address, end address).
// Terminates the list by writing a pair of two zeroes.
// Returns the number of written bytes.
uint64_t writeAddressRanges(
raw_svector_ostream &Stream,
const DebugAddressRangesVector &AddressRanges,
const bool WriteRelativeRanges = false) {
for (const DebugAddressRange &Range : AddressRanges) {
support::endian::write(Stream, Range.LowPC, support::little);
support::endian::write(
Stream, WriteRelativeRanges ? Range.HighPC - Range.LowPC : Range.HighPC,
support::little);
}
// Finish with 0 entries.
support::endian::write(Stream, 0ULL, support::little);
support::endian::write(Stream, 0ULL, support::little);
return AddressRanges.size() * 16 + 16;
}
} // namespace
DebugRangesSectionWriter::DebugRangesSectionWriter() {
RangesBuffer = std::make_unique<DebugBufferVector>();
RangesStream = std::make_unique<raw_svector_ostream>(*RangesBuffer);
// Add an empty range as the first entry;
SectionOffset +=
writeAddressRanges(*RangesStream.get(), DebugAddressRangesVector{});
}
uint64_t DebugRangesSectionWriter::addRanges(
DebugAddressRangesVector &&Ranges,
std::map<DebugAddressRangesVector, uint64_t> &CachedRanges) {
if (Ranges.empty())
return getEmptyRangesOffset();
const auto RI = CachedRanges.find(Ranges);
if (RI != CachedRanges.end())
return RI->second;
const uint64_t EntryOffset = addRanges(Ranges);
CachedRanges.emplace(std::move(Ranges), EntryOffset);
return EntryOffset;
}
uint64_t
DebugRangesSectionWriter::addRanges(const DebugAddressRangesVector &Ranges) {
if (Ranges.empty())
return getEmptyRangesOffset();
// Reading the SectionOffset and updating it should be atomic to guarantee
// unique and correct offsets in patches.
std::lock_guard<std::mutex> Lock(WriterMutex);
const uint32_t EntryOffset = SectionOffset;
SectionOffset += writeAddressRanges(*RangesStream.get(), Ranges);
return EntryOffset;
}
uint64_t DebugRangesSectionWriter::getSectionOffset() {
std::lock_guard<std::mutex> Lock(WriterMutex);
return SectionOffset;
}
void DebugARangesSectionWriter::addCURanges(uint64_t CUOffset,
DebugAddressRangesVector &&Ranges) {
std::lock_guard<std::mutex> Lock(CUAddressRangesMutex);
CUAddressRanges.emplace(CUOffset, std::move(Ranges));
}
void DebugARangesSectionWriter::writeARangesSection(
raw_svector_ostream &RangesStream) const {
// For reference on the format of the .debug_aranges section, see the DWARF4
// specification, section 6.1.4 Lookup by Address
// http://www.dwarfstd.org/doc/DWARF4.pdf
for (const auto &CUOffsetAddressRangesPair : CUAddressRanges) {
const uint64_t Offset = CUOffsetAddressRangesPair.first;
const DebugAddressRangesVector &AddressRanges =
CUOffsetAddressRangesPair.second;
// Emit header.
// Size of this set: 8 (size of the header) + 4 (padding after header)
// + 2*sizeof(uint64_t) bytes for each of the ranges, plus an extra
// pair of uint64_t's for the terminating, zero-length range.
// Does not include size field itself.
uint32_t Size = 8 + 4 + 2*sizeof(uint64_t) * (AddressRanges.size() + 1);
// Header field #1: set size.
support::endian::write(RangesStream, Size, support::little);
// Header field #2: version number, 2 as per the specification.
support::endian::write(RangesStream, static_cast<uint16_t>(2),
support::little);
// Header field #3: debug info offset of the correspondent compile unit.
support::endian::write(RangesStream, static_cast<uint32_t>(Offset),
support::little);
// Header field #4: address size.
// 8 since we only write ELF64 binaries for now.
RangesStream << char(8);
// Header field #5: segment size of target architecture.
RangesStream << char(0);
// Padding before address table - 4 bytes in the 64-bit-pointer case.
support::endian::write(RangesStream, static_cast<uint32_t>(0),
support::little);
writeAddressRanges(RangesStream, AddressRanges, true);
}
}
DebugAddrWriter::DebugAddrWriter(BinaryContext *Bc) { BC = Bc; }
void DebugAddrWriter::AddressForDWOCU::dump() {
std::vector<IndexAddressPair> SortedMap(indexToAddressBegin(),
indexToAdddessEnd());
// Sorting address in increasing order of indices.
std::sort(SortedMap.begin(), SortedMap.end(),
[](const IndexAddressPair &A, const IndexAddressPair &B) {
return A.first < B.first;
});
for (auto &Pair : SortedMap)
dbgs() << Twine::utohexstr(Pair.second) << "\t" << Pair.first << "\n";
}
uint32_t DebugAddrWriter::getIndexFromAddress(uint64_t Address,
uint64_t DWOId) {
if (!AddressMaps.count(DWOId))
AddressMaps[DWOId] = AddressForDWOCU();
AddressForDWOCU &Map = AddressMaps[DWOId];
auto Entry = Map.find(Address);
if (Entry == Map.end()) {
auto Index = Map.getNextIndex();
Entry = Map.insert(Address, Index).first;
}
return Entry->second;
}
// Case1) Address is not in map insert in to AddresToIndex and IndexToAddres
// Case2) Address is in the map but Index is higher or equal. Need to update
// IndexToAddrss. Case3) Address is in the map but Index is lower. Need to
// update AddressToIndex and IndexToAddress
void DebugAddrWriter::addIndexAddress(uint64_t Address, uint32_t Index,
uint64_t DWOId) {
AddressForDWOCU &Map = AddressMaps[DWOId];
auto Entry = Map.find(Address);
if (Entry != Map.end()) {
if (Entry->second > Index)
Map.updateAddressToIndex(Address, Index);
Map.updateIndexToAddrss(Address, Index);
} else
Map.insert(Address, Index);
}
AddressSectionBuffer DebugAddrWriter::finalize() {
// Need to layout all sections within .debug_addr
// Within each section sort Address by index.
AddressSectionBuffer Buffer;
raw_svector_ostream AddressStream(Buffer);
for (std::unique_ptr<DWARFUnit> &CU : BC->DwCtx->compile_units()) {
Optional<uint64_t> DWOId = CU->getDWOId();
// Handling the case wehre debug information is a mix of Debug fission and
// monolitic.
if (!DWOId)
continue;
auto AM = AddressMaps.find(*DWOId);
// Adding to map even if it did not contribute to .debug_addr.
// The Skeleton CU will still have DW_AT_GNU_addr_base.
DWOIdToOffsetMap[*DWOId] = Buffer.size();
// If does not exist this CUs DWO section didn't contribute to .debug_addr.
if (AM == AddressMaps.end())
continue;
std::vector<IndexAddressPair> SortedMap(AM->second.indexToAddressBegin(),
AM->second.indexToAdddessEnd());
// Sorting address in increasing order of indices.
std::sort(SortedMap.begin(), SortedMap.end(),
[](const IndexAddressPair &A, const IndexAddressPair &B) {
return A.first < B.first;
});
uint8_t AddrSize = CU->getAddressByteSize();
uint32_t Counter = 0;
auto WriteAddress = [&](uint64_t Address) -> void {
++Counter;
switch (AddrSize) {
default:
assert(false && "Address Size is invalid.");
break;
case 4:
support::endian::write(AddressStream, static_cast<uint32_t>(Address),
support::little);
break;
case 8:
support::endian::write(AddressStream, Address, support::little);
break;
}
};
for (const IndexAddressPair &Val : SortedMap) {
while (Val.first > Counter)
WriteAddress(0);
WriteAddress(Val.second);
}
}
return Buffer;
}
uint64_t DebugAddrWriter::getOffset(uint64_t DWOId) {
auto Iter = DWOIdToOffsetMap.find(DWOId);
assert(Iter != DWOIdToOffsetMap.end() &&
"Offset in to.debug_addr was not found for DWO ID.");
return Iter->second;
}
DebugLocWriter::DebugLocWriter(BinaryContext *BC) {
LocBuffer = std::make_unique<DebugBufferVector>();
LocStream = std::make_unique<raw_svector_ostream>(*LocBuffer);
}
void DebugLocWriter::addList(uint64_t AttrOffset,
DebugLocationsVector &&LocList) {
if (LocList.empty()) {
EmptyAttrLists.push_back(AttrOffset);
return;
}
// Since there is a separate DebugLocWriter for each thread,
// we don't need a lock to read the SectionOffset and update it.
const uint32_t EntryOffset = SectionOffset;
for (const DebugLocationEntry &Entry : LocList) {
support::endian::write(*LocStream, static_cast<uint64_t>(Entry.LowPC),
support::little);
support::endian::write(*LocStream, static_cast<uint64_t>(Entry.HighPC),
support::little);
support::endian::write(*LocStream, static_cast<uint16_t>(Entry.Expr.size()),
support::little);
*LocStream << StringRef(reinterpret_cast<const char *>(Entry.Expr.data()),
Entry.Expr.size());
SectionOffset += 2 * 8 + 2 + Entry.Expr.size();
}
LocStream->write_zeros(16);
SectionOffset += 16;
LocListDebugInfoPatches.push_back({AttrOffset, EntryOffset});
}
void DebugLoclistWriter::addList(uint64_t AttrOffset,
DebugLocationsVector &&LocList) {
Patches.push_back({AttrOffset, std::move(LocList)});
}
std::unique_ptr<DebugBufferVector> DebugLocWriter::getBuffer() {
return std::move(LocBuffer);
}
// DWARF 4: 2.6.2
void DebugLocWriter::finalize(uint64_t SectionOffset,
SimpleBinaryPatcher &DebugInfoPatcher) {
for (const auto LocListDebugInfoPatchType : LocListDebugInfoPatches) {
uint64_t Offset = SectionOffset + LocListDebugInfoPatchType.LocListOffset;
DebugInfoPatcher.addLE32Patch(LocListDebugInfoPatchType.DebugInfoAttrOffset,
Offset);
}
for (uint64_t DebugInfoAttrOffset : EmptyAttrLists)
DebugInfoPatcher.addLE32Patch(DebugInfoAttrOffset,
DebugLocWriter::EmptyListOffset);
}
void DebugLoclistWriter::finalize(uint64_t SectionOffset,
SimpleBinaryPatcher &DebugInfoPatcher) {
for (LocPatch &Patch : Patches) {
if (Patch.LocList.empty()) {
DebugInfoPatcher.addLE32Patch(Patch.AttrOffset,
DebugLocWriter::EmptyListOffset);
continue;
}
const uint32_t EntryOffset = LocBuffer->size();
for (const DebugLocationEntry &Entry : Patch.LocList) {
support::endian::write(*LocStream,
static_cast<uint8_t>(dwarf::DW_LLE_startx_length),
support::little);
uint32_t Index = AddrWriter->getIndexFromAddress(Entry.LowPC, DWOId);
encodeULEB128(Index, *LocStream);
// TODO: Support DWARF5
support::endian::write(*LocStream,
static_cast<uint32_t>(Entry.HighPC - Entry.LowPC),
support::little);
support::endian::write(*LocStream,
static_cast<uint16_t>(Entry.Expr.size()),
support::little);
*LocStream << StringRef(reinterpret_cast<const char *>(Entry.Expr.data()),
Entry.Expr.size());
}
support::endian::write(*LocStream,
static_cast<uint8_t>(dwarf::DW_LLE_end_of_list),
support::little);
DebugInfoPatcher.addLE32Patch(Patch.AttrOffset, EntryOffset);
clearList(Patch.LocList);
}
clearList(Patches);
}
DebugAddrWriter *DebugLoclistWriter::AddrWriter = nullptr;
void SimpleBinaryPatcher::addBinaryPatch(uint32_t Offset,
const std::string &NewValue) {
Patches.emplace_back(Offset, NewValue);
}
void SimpleBinaryPatcher::addBytePatch(uint32_t Offset, uint8_t Value) {
Patches.emplace_back(Offset, std::string(1, Value));
}
void SimpleBinaryPatcher::addLEPatch(uint32_t Offset, uint64_t NewValue,
size_t ByteSize) {
std::string LE64(ByteSize, 0);
for (size_t I = 0; I < ByteSize; ++I) {
LE64[I] = NewValue & 0xff;
NewValue >>= 8;
}
Patches.emplace_back(Offset, LE64);
}
void SimpleBinaryPatcher::addUDataPatch(uint32_t Offset, uint64_t Value, uint64_t Size) {
std::string Buff;
raw_string_ostream OS(Buff);
encodeULEB128(Value, OS, Size);
Patches.emplace_back(Offset, OS.str());
}
void SimpleBinaryPatcher::addLE64Patch(uint32_t Offset, uint64_t NewValue) {
addLEPatch(Offset, NewValue, 8);
}
void SimpleBinaryPatcher::addLE32Patch(uint32_t Offset, uint32_t NewValue) {
addLEPatch(Offset, NewValue, 4);
}
void SimpleBinaryPatcher::patchBinary(std::string &BinaryContents,
uint32_t DWPOffset = 0) {
for (const auto &Patch : Patches) {
uint32_t Offset = Patch.first - DWPOffset;
const std::string &ByteSequence = Patch.second;
assert(Offset + ByteSequence.size() <= BinaryContents.size() &&
"Applied patch runs over binary size.");
for (uint64_t I = 0, Size = ByteSequence.size(); I < Size; ++I) {
BinaryContents[Offset + I] = ByteSequence[I];
}
}
}
void DebugStrWriter::create() {
StrBuffer = std::make_unique<DebugStrBufferVector>();
StrStream = std::make_unique<raw_svector_ostream>(*StrBuffer);
}
void DebugStrWriter::initialize() {
auto StrSection = BC->DwCtx->getDWARFObj().getStrSection();
(*StrStream) << StrSection;
}
uint32_t DebugStrWriter::addString(StringRef Str) {
if (StrBuffer->empty())
initialize();
auto Offset = StrBuffer->size();
(*StrStream) << Str;
StrStream->write_zeros(1);
return Offset;
}
void DebugAbbrevWriter::addUnitAbbreviations(DWARFUnit &Unit) {
const DWARFAbbreviationDeclarationSet *Abbrevs = Unit.getAbbreviations();
if (!Abbrevs)
return;
// Multiple units may share the same abbreviations. Only add abbreviations
// for the first unit and reuse them.
const uint64_t AbbrevOffset = Unit.getAbbreviationsOffset();
if (CUAbbrevData.find(AbbrevOffset) != CUAbbrevData.end())
return;
std::lock_guard<std::mutex> Lock(WriterMutex);
AbbrevData &UnitData = CUAbbrevData[AbbrevOffset];
UnitData.Buffer = std::make_unique<DebugBufferVector>();
UnitData.Stream = std::make_unique<raw_svector_ostream>(*UnitData.Buffer);
const auto &UnitPatches = Patches[&Unit];
raw_svector_ostream &OS = *UnitData.Stream.get();
// Take a fast path if there are no patches to apply. Simply copy the original
// contents.
if (UnitPatches.empty()) {
StringRef AbbrevSectionContents =
Unit.isDWOUnit() ? Unit.getContext().getDWARFObj().getAbbrevDWOSection()
: Unit.getContext().getDWARFObj().getAbbrevSection();
StringRef AbbrevContents;
const DWARFUnitIndex &CUIndex = Unit.getContext().getCUIndex();
if (!CUIndex.getRows().empty()) {
// Handle DWP section contribution.
const DWARFUnitIndex::Entry *DWOEntry =
CUIndex.getFromHash(*Unit.getDWOId());
if (!DWOEntry)
return;
const DWARFUnitIndex::Entry::SectionContribution *DWOContrubution =
DWOEntry->getContribution(DWARFSectionKind::DW_SECT_ABBREV);
AbbrevContents = AbbrevSectionContents.substr(DWOContrubution->Offset,
DWOContrubution->Length);
} else {
DWARFCompileUnit *NextUnit =
Unit.getContext().getCompileUnitForOffset(Unit.getNextUnitOffset());
const uint64_t StartOffset = Unit.getAbbreviationsOffset();
const uint64_t EndOffset = NextUnit ? NextUnit->getAbbreviationsOffset()
: AbbrevSectionContents.size();
AbbrevContents = AbbrevSectionContents.slice(StartOffset, EndOffset);
}
OS.reserveExtraSpace(AbbrevContents.size());
OS << AbbrevContents;
return;
}
for (auto I = Abbrevs->begin(), E = Abbrevs->end(); I != E; ++I) {
const DWARFAbbreviationDeclaration &Abbrev = *I;
auto Patch = UnitPatches.find(&Abbrev);
encodeULEB128(Abbrev.getCode(), OS);
encodeULEB128(Abbrev.getTag(), OS);
encodeULEB128(Abbrev.hasChildren(), OS);
for (const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec :
Abbrev.attributes()) {
if (Patch != UnitPatches.end()) {
bool Patched = false;
// Patches added later take a precedence over earlier ones.
for (auto I = Patch->second.rbegin(), E = Patch->second.rend(); I != E;
++I) {
if (I->OldAttr != AttrSpec.Attr)
continue;
encodeULEB128(I->NewAttr, OS);
encodeULEB128(I->NewAttrForm, OS);
Patched = true;
break;
}
if (Patched)
continue;
}
encodeULEB128(AttrSpec.Attr, OS);
encodeULEB128(AttrSpec.Form, OS);
if (AttrSpec.isImplicitConst())
encodeSLEB128(AttrSpec.getImplicitConstValue(), OS);
}
encodeULEB128(0, OS);
encodeULEB128(0, OS);
}
encodeULEB128(0, OS);
}
std::unique_ptr<DebugBufferVector> DebugAbbrevWriter::finalize() {
DebugBufferVector ReturnBuffer;
// Pre-calculate the total size of abbrev section.
uint64_t Size = 0;
for (const auto &KV : CUAbbrevData) {
const AbbrevData &UnitData = KV.second;
Size += UnitData.Buffer->size();
}
ReturnBuffer.reserve(Size);
uint64_t Pos = 0;
for (auto &KV : CUAbbrevData) {
AbbrevData &UnitData = KV.second;
ReturnBuffer.append(*UnitData.Buffer);
UnitData.Offset = Pos;
Pos += UnitData.Buffer->size();
UnitData.Buffer.reset();
UnitData.Stream.reset();
}
return std::make_unique<DebugBufferVector>(ReturnBuffer);
}
static void emitDwarfSetLineAddrAbs(MCStreamer &OS,
MCDwarfLineTableParams Params,
int64_t LineDelta, uint64_t Address,
int PointerSize) {
// emit the sequence to set the address
OS.emitIntValue(dwarf::DW_LNS_extended_op, 1);
OS.emitULEB128IntValue(PointerSize + 1);
OS.emitIntValue(dwarf::DW_LNE_set_address, 1);
OS.emitIntValue(Address, PointerSize);
// emit the sequence for the LineDelta (from 1) and a zero address delta.
MCDwarfLineAddr::Emit(&OS, Params, LineDelta, 0);
}
static inline void emitBinaryDwarfLineTable(
MCStreamer *MCOS, MCDwarfLineTableParams Params,
const DWARFDebugLine::LineTable *Table,
const std::vector<DwarfLineTable::RowSequence> &InputSequences) {
if (InputSequences.empty())
return;
constexpr uint64_t InvalidAddress = UINT64_MAX;
unsigned FileNum = 1;
unsigned LastLine = 1;
unsigned Column = 0;
unsigned Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0;
unsigned Isa = 0;
unsigned Discriminator = 0;
uint64_t LastAddress = InvalidAddress;
uint64_t PrevEndOfSequence = InvalidAddress;
const MCAsmInfo *AsmInfo = MCOS->getContext().getAsmInfo();
auto emitEndOfSequence = [&](uint64_t Address) {
MCDwarfLineAddr::Emit(MCOS, Params, INT64_MAX, Address - LastAddress);
FileNum = 1;
LastLine = 1;
Column = 0;
Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0;
Isa = 0;
Discriminator = 0;
LastAddress = InvalidAddress;
};
for (const DwarfLineTable::RowSequence &Sequence : InputSequences) {
const uint64_t SequenceStart =
Table->Rows[Sequence.FirstIndex].Address.Address;
// Check if we need to mark the end of the sequence.
if (PrevEndOfSequence != InvalidAddress && LastAddress != InvalidAddress &&
PrevEndOfSequence != SequenceStart) {
emitEndOfSequence(PrevEndOfSequence);
}
for (uint32_t RowIndex = Sequence.FirstIndex;
RowIndex <= Sequence.LastIndex; ++RowIndex) {
const DWARFDebugLine::Row &Row = Table->Rows[RowIndex];
int64_t LineDelta = static_cast<int64_t>(Row.Line) - LastLine;
const uint64_t Address = Row.Address.Address;
if (FileNum != Row.File) {
FileNum = Row.File;
MCOS->emitInt8(dwarf::DW_LNS_set_file);
MCOS->emitULEB128IntValue(FileNum);
}
if (Column != Row.Column) {
Column = Row.Column;
MCOS->emitInt8(dwarf::DW_LNS_set_column);
MCOS->emitULEB128IntValue(Column);
}
if (Discriminator != Row.Discriminator &&
MCOS->getContext().getDwarfVersion() >= 4) {
Discriminator = Row.Discriminator;
unsigned Size = getULEB128Size(Discriminator);
MCOS->emitInt8(dwarf::DW_LNS_extended_op);
MCOS->emitULEB128IntValue(Size + 1);
MCOS->emitInt8(dwarf::DW_LNE_set_discriminator);
MCOS->emitULEB128IntValue(Discriminator);
}
if (Isa != Row.Isa) {
Isa = Row.Isa;
MCOS->emitInt8(dwarf::DW_LNS_set_isa);
MCOS->emitULEB128IntValue(Isa);
}
if (Row.IsStmt != Flags) {
Flags = Row.IsStmt;
MCOS->emitInt8(dwarf::DW_LNS_negate_stmt);
}
if (Row.BasicBlock)
MCOS->emitInt8(dwarf::DW_LNS_set_basic_block);
if (Row.PrologueEnd)
MCOS->emitInt8(dwarf::DW_LNS_set_prologue_end);
if (Row.EpilogueBegin)
MCOS->emitInt8(dwarf::DW_LNS_set_epilogue_begin);
// The end of the sequence is not normal in the middle of the input
// sequence, but could happen, e.g. for assembly code.
if (Row.EndSequence) {
emitEndOfSequence(Address);
} else {
if (LastAddress == InvalidAddress)
emitDwarfSetLineAddrAbs(*MCOS, Params, LineDelta, Address,
AsmInfo->getCodePointerSize());
else
MCDwarfLineAddr::Emit(MCOS, Params, LineDelta, Address - LastAddress);
LastAddress = Address;
LastLine = Row.Line;
}
Discriminator = 0;
}
PrevEndOfSequence = Sequence.EndAddress;
}
// Finish with the end of the sequence.
if (LastAddress != InvalidAddress)
emitEndOfSequence(PrevEndOfSequence);
}
// This function is similar to the one from MCDwarfLineTable, except it handles
// end-of-sequence entries differently by utilizing line entries with
// DWARF2_FLAG_END_SEQUENCE flag.
static inline void emitDwarfLineTable(
MCStreamer *MCOS, MCSection *Section,
const MCLineSection::MCDwarfLineEntryCollection &LineEntries) {
unsigned FileNum = 1;
unsigned LastLine = 1;
unsigned Column = 0;
unsigned Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0;
unsigned Isa = 0;
unsigned Discriminator = 0;
MCSymbol *LastLabel = nullptr;
const MCAsmInfo *AsmInfo = MCOS->getContext().getAsmInfo();
// Loop through each MCDwarfLineEntry and encode the dwarf line number table.
for (const MCDwarfLineEntry &LineEntry : LineEntries) {
if (LineEntry.getFlags() & DWARF2_FLAG_END_SEQUENCE) {
MCOS->emitDwarfAdvanceLineAddr(INT64_MAX, LastLabel, LineEntry.getLabel(),
AsmInfo->getCodePointerSize());
FileNum = 1;
LastLine = 1;
Column = 0;
Flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_IS_STMT : 0;
Isa = 0;
Discriminator = 0;
LastLabel = nullptr;
continue;
}
int64_t LineDelta = static_cast<int64_t>(LineEntry.getLine()) - LastLine;
if (FileNum != LineEntry.getFileNum()) {
FileNum = LineEntry.getFileNum();
MCOS->emitInt8(dwarf::DW_LNS_set_file);
MCOS->emitULEB128IntValue(FileNum);
}
if (Column != LineEntry.getColumn()) {
Column = LineEntry.getColumn();
MCOS->emitInt8(dwarf::DW_LNS_set_column);
MCOS->emitULEB128IntValue(Column);
}
if (Discriminator != LineEntry.getDiscriminator() &&
MCOS->getContext().getDwarfVersion() >= 4) {
Discriminator = LineEntry.getDiscriminator();
unsigned Size = getULEB128Size(Discriminator);
MCOS->emitInt8(dwarf::DW_LNS_extended_op);
MCOS->emitULEB128IntValue(Size + 1);
MCOS->emitInt8(dwarf::DW_LNE_set_discriminator);
MCOS->emitULEB128IntValue(Discriminator);
}
if (Isa != LineEntry.getIsa()) {
Isa = LineEntry.getIsa();
MCOS->emitInt8(dwarf::DW_LNS_set_isa);
MCOS->emitULEB128IntValue(Isa);
}
if ((LineEntry.getFlags() ^ Flags) & DWARF2_FLAG_IS_STMT) {
Flags = LineEntry.getFlags();
MCOS->emitInt8(dwarf::DW_LNS_negate_stmt);
}
if (LineEntry.getFlags() & DWARF2_FLAG_BASIC_BLOCK)
MCOS->emitInt8(dwarf::DW_LNS_set_basic_block);
if (LineEntry.getFlags() & DWARF2_FLAG_PROLOGUE_END)
MCOS->emitInt8(dwarf::DW_LNS_set_prologue_end);
if (LineEntry.getFlags() & DWARF2_FLAG_EPILOGUE_BEGIN)
MCOS->emitInt8(dwarf::DW_LNS_set_epilogue_begin);
MCSymbol *Label = LineEntry.getLabel();
// At this point we want to emit/create the sequence to encode the delta
// in line numbers and the increment of the address from the previous
// Label and the current Label.
MCOS->emitDwarfAdvanceLineAddr(LineDelta, LastLabel, Label,
AsmInfo->getCodePointerSize());
Discriminator = 0;
LastLine = LineEntry.getLine();
LastLabel = Label;
}
assert(LastLabel == nullptr && "end of sequence expected");
}
void DwarfLineTable::emitCU(MCStreamer *MCOS, MCDwarfLineTableParams Params,
Optional<MCDwarfLineStr> &LineStr) const {
if (!RawData.empty()) {
assert(MCLineSections.getMCLineEntries().empty() &&
InputSequences.empty() &&
"cannot combine raw data with new line entries");
MCOS->emitLabel(getLabel());
MCOS->emitBytes(RawData);
return;
}
MCSymbol *LineEndSym = Header.Emit(MCOS, Params, LineStr).second;
// Put out the line tables.
for (const auto &LineSec : MCLineSections.getMCLineEntries())
emitDwarfLineTable(MCOS, LineSec.first, LineSec.second);
// Emit line tables for the original code.
emitBinaryDwarfLineTable(MCOS, Params, InputTable, InputSequences);
// This is the end of the section, so set the value of the symbol at the end
// of this section (that was used in a previous expression).
MCOS->emitLabel(LineEndSym);
}
void DwarfLineTable::emit(BinaryContext &BC, MCStreamer &Streamer) {
MCAssembler &Assembler =
static_cast<MCObjectStreamer *>(&Streamer)->getAssembler();
MCDwarfLineTableParams Params = Assembler.getDWARFLinetableParams();
auto &LineTables = BC.getDwarfLineTables();
// Bail out early so we don't switch to the debug_line section needlessly and
// in doing so create an unnecessary (if empty) section.
if (LineTables.empty())
return;
// In a v5 non-split line table, put the strings in a separate section.
Optional<MCDwarfLineStr> LineStr(None);
if (BC.Ctx->getDwarfVersion() >= 5)
LineStr = MCDwarfLineStr(*BC.Ctx);
// Switch to the section where the table will be emitted into.
Streamer.SwitchSection(BC.MOFI->getDwarfLineSection());
// Handle the rest of the Compile Units.
for (auto &CUIDTablePair : LineTables) {
CUIDTablePair.second.emitCU(&Streamer, Params, LineStr);
}
}
} // namespace bolt
} // namespace llvm
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