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llvm-project/llvm/lib/DWARFLinker/DWARFStreamer.cpp
Alexey Lapshin 536f35ea62 [DWARFLinker][DWARFv5] Support debug_loclists. 
This patch adds support of DWARFv5 .debug_loclists table.
As DWARFLinker resolves relocations, it is able to always
use DW_FORM_addr instead of DW_FORM_addrx. DW_FORM_addrx
helps to minimize number of relocations, it is also used for
split DWARF. Both of these cases are not relevant for the
DWARFLinker. Thus, this patch converts all DW_FORM_addrx
forms into the DW_FORM_addr. And, as the result, it converts
location lists of DW_FORM_loclistx form into the DW_FORM_sec_offset.
For the --update case all DW_FORM_addrx, DW_FORM_loclistx
are preserved as is.

Depends On D145499

Differential Revision: https://reviews.llvm.org/D145680
2023-03-15 11:36:59 +01:00

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//===- DwarfStreamer.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/DWARFLinker/DWARFStreamer.h"
#include "llvm/CodeGen/NonRelocatableStringpool.h"
#include "llvm/DWARFLinker/DWARFLinkerCompileUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/MC/MCTargetOptionsCommandFlags.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/TargetParser/Triple.h"
namespace llvm {
bool DwarfStreamer::init(Triple TheTriple,
StringRef Swift5ReflectionSegmentName) {
std::string ErrorStr;
std::string TripleName;
StringRef Context = "dwarf streamer init";
// Get the target.
const Target *TheTarget =
TargetRegistry::lookupTarget(TripleName, TheTriple, ErrorStr);
if (!TheTarget)
return error(ErrorStr, Context), false;
TripleName = TheTriple.getTriple();
// Create all the MC Objects.
MRI.reset(TheTarget->createMCRegInfo(TripleName));
if (!MRI)
return error(Twine("no register info for target ") + TripleName, Context),
false;
MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags();
MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
if (!MAI)
return error("no asm info for target " + TripleName, Context), false;
MSTI.reset(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
if (!MSTI)
return error("no subtarget info for target " + TripleName, Context), false;
MC.reset(new MCContext(TheTriple, MAI.get(), MRI.get(), MSTI.get(), nullptr,
nullptr, true, Swift5ReflectionSegmentName));
MOFI.reset(TheTarget->createMCObjectFileInfo(*MC, /*PIC=*/false, false));
MC->setObjectFileInfo(MOFI.get());
MAB = TheTarget->createMCAsmBackend(*MSTI, *MRI, MCOptions);
if (!MAB)
return error("no asm backend for target " + TripleName, Context), false;
MII.reset(TheTarget->createMCInstrInfo());
if (!MII)
return error("no instr info info for target " + TripleName, Context), false;
MCE = TheTarget->createMCCodeEmitter(*MII, *MC);
if (!MCE)
return error("no code emitter for target " + TripleName, Context), false;
switch (OutFileType) {
case OutputFileType::Assembly: {
MIP = TheTarget->createMCInstPrinter(TheTriple, MAI->getAssemblerDialect(),
*MAI, *MII, *MRI);
MS = TheTarget->createAsmStreamer(
*MC, std::make_unique<formatted_raw_ostream>(OutFile), true, true, MIP,
std::unique_ptr<MCCodeEmitter>(MCE), std::unique_ptr<MCAsmBackend>(MAB),
true);
break;
}
case OutputFileType::Object: {
MS = TheTarget->createMCObjectStreamer(
TheTriple, *MC, std::unique_ptr<MCAsmBackend>(MAB),
MAB->createObjectWriter(OutFile), std::unique_ptr<MCCodeEmitter>(MCE),
*MSTI, MCOptions.MCRelaxAll, MCOptions.MCIncrementalLinkerCompatible,
/*DWARFMustBeAtTheEnd*/ false);
break;
}
}
if (!MS)
return error("no object streamer for target " + TripleName, Context), false;
// Finally create the AsmPrinter we'll use to emit the DIEs.
TM.reset(TheTarget->createTargetMachine(TripleName, "", "", TargetOptions(),
std::nullopt));
if (!TM)
return error("no target machine for target " + TripleName, Context), false;
Asm.reset(TheTarget->createAsmPrinter(*TM, std::unique_ptr<MCStreamer>(MS)));
if (!Asm)
return error("no asm printer for target " + TripleName, Context), false;
Asm->setDwarfUsesRelocationsAcrossSections(false);
RangesSectionSize = 0;
RngListsSectionSize = 0;
LocSectionSize = 0;
LocListsSectionSize = 0;
LineSectionSize = 0;
FrameSectionSize = 0;
DebugInfoSectionSize = 0;
MacInfoSectionSize = 0;
MacroSectionSize = 0;
return true;
}
void DwarfStreamer::finish() { MS->finish(); }
void DwarfStreamer::switchToDebugInfoSection(unsigned DwarfVersion) {
MS->switchSection(MOFI->getDwarfInfoSection());
MC->setDwarfVersion(DwarfVersion);
}
/// Emit the compilation unit header for \p Unit in the debug_info section.
///
/// A Dwarf 4 section header is encoded as:
/// uint32_t Unit length (omitting this field)
/// uint16_t Version
/// uint32_t Abbreviation table offset
/// uint8_t Address size
/// Leading to a total of 11 bytes.
///
/// A Dwarf 5 section header is encoded as:
/// uint32_t Unit length (omitting this field)
/// uint16_t Version
/// uint8_t Unit type
/// uint8_t Address size
/// uint32_t Abbreviation table offset
/// Leading to a total of 12 bytes.
void DwarfStreamer::emitCompileUnitHeader(CompileUnit &Unit,
unsigned DwarfVersion) {
switchToDebugInfoSection(DwarfVersion);
/// The start of the unit within its section.
Unit.setLabelBegin(Asm->createTempSymbol("cu_begin"));
Asm->OutStreamer->emitLabel(Unit.getLabelBegin());
// Emit size of content not including length itself. The size has already
// been computed in CompileUnit::computeOffsets(). Subtract 4 to that size to
// account for the length field.
Asm->emitInt32(Unit.getNextUnitOffset() - Unit.getStartOffset() - 4);
Asm->emitInt16(DwarfVersion);
if (DwarfVersion >= 5) {
Asm->emitInt8(dwarf::DW_UT_compile);
Asm->emitInt8(Unit.getOrigUnit().getAddressByteSize());
// We share one abbreviations table across all units so it's always at the
// start of the section.
Asm->emitInt32(0);
DebugInfoSectionSize += 12;
} else {
// We share one abbreviations table across all units so it's always at the
// start of the section.
Asm->emitInt32(0);
Asm->emitInt8(Unit.getOrigUnit().getAddressByteSize());
DebugInfoSectionSize += 11;
}
// Remember this CU.
EmittedUnits.push_back({Unit.getUniqueID(), Unit.getLabelBegin()});
}
/// Emit the \p Abbrevs array as the shared abbreviation table
/// for the linked Dwarf file.
void DwarfStreamer::emitAbbrevs(
const std::vector<std::unique_ptr<DIEAbbrev>> &Abbrevs,
unsigned DwarfVersion) {
MS->switchSection(MOFI->getDwarfAbbrevSection());
MC->setDwarfVersion(DwarfVersion);
Asm->emitDwarfAbbrevs(Abbrevs);
}
/// Recursively emit the DIE tree rooted at \p Die.
void DwarfStreamer::emitDIE(DIE &Die) {
MS->switchSection(MOFI->getDwarfInfoSection());
Asm->emitDwarfDIE(Die);
DebugInfoSectionSize += Die.getSize();
}
/// Emit contents of section SecName From Obj.
void DwarfStreamer::emitSectionContents(StringRef SecData, StringRef SecName) {
MCSection *Section =
StringSwitch<MCSection *>(SecName)
.Case("debug_line", MC->getObjectFileInfo()->getDwarfLineSection())
.Case("debug_loc", MC->getObjectFileInfo()->getDwarfLocSection())
.Case("debug_ranges",
MC->getObjectFileInfo()->getDwarfRangesSection())
.Case("debug_frame", MC->getObjectFileInfo()->getDwarfFrameSection())
.Case("debug_aranges",
MC->getObjectFileInfo()->getDwarfARangesSection())
.Case("debug_addr", MC->getObjectFileInfo()->getDwarfAddrSection())
.Case("debug_rnglists",
MC->getObjectFileInfo()->getDwarfRnglistsSection())
.Case("debug_loclists",
MC->getObjectFileInfo()->getDwarfLoclistsSection())
.Default(nullptr);
if (Section) {
MS->switchSection(Section);
MS->emitBytes(SecData);
}
}
/// Emit DIE containing warnings.
void DwarfStreamer::emitPaperTrailWarningsDie(DIE &Die) {
switchToDebugInfoSection(/* Version */ 2);
auto &Asm = getAsmPrinter();
Asm.emitInt32(11 + Die.getSize() - 4);
Asm.emitInt16(2);
Asm.emitInt32(0);
Asm.emitInt8(MC->getTargetTriple().isArch64Bit() ? 8 : 4);
DebugInfoSectionSize += 11;
emitDIE(Die);
}
/// Emit the debug_str section stored in \p Pool.
void DwarfStreamer::emitStrings(const NonRelocatableStringpool &Pool) {
Asm->OutStreamer->switchSection(MOFI->getDwarfStrSection());
std::vector<DwarfStringPoolEntryRef> Entries = Pool.getEntriesForEmission();
for (auto Entry : Entries) {
// Emit the string itself.
Asm->OutStreamer->emitBytes(Entry.getString());
// Emit a null terminator.
Asm->emitInt8(0);
}
#if 0
if (DwarfVersion >= 5) {
// Emit an empty string offset section.
Asm->OutStreamer->switchSection(MOFI->getDwarfStrOffSection());
Asm->emitDwarfUnitLength(4, "Length of String Offsets Set");
Asm->emitInt16(DwarfVersion);
Asm->emitInt16(0);
}
#endif
}
void DwarfStreamer::emitDebugNames(
AccelTable<DWARF5AccelTableStaticData> &Table) {
if (EmittedUnits.empty())
return;
// Build up data structures needed to emit this section.
std::vector<MCSymbol *> CompUnits;
DenseMap<unsigned, size_t> UniqueIdToCuMap;
unsigned Id = 0;
for (auto &CU : EmittedUnits) {
CompUnits.push_back(CU.LabelBegin);
// We might be omitting CUs, so we need to remap them.
UniqueIdToCuMap[CU.ID] = Id++;
}
Asm->OutStreamer->switchSection(MOFI->getDwarfDebugNamesSection());
emitDWARF5AccelTable(
Asm.get(), Table, CompUnits,
[&UniqueIdToCuMap](const DWARF5AccelTableStaticData &Entry) {
return UniqueIdToCuMap[Entry.getCUIndex()];
});
}
void DwarfStreamer::emitAppleNamespaces(
AccelTable<AppleAccelTableStaticOffsetData> &Table) {
Asm->OutStreamer->switchSection(MOFI->getDwarfAccelNamespaceSection());
auto *SectionBegin = Asm->createTempSymbol("namespac_begin");
Asm->OutStreamer->emitLabel(SectionBegin);
emitAppleAccelTable(Asm.get(), Table, "namespac", SectionBegin);
}
void DwarfStreamer::emitAppleNames(
AccelTable<AppleAccelTableStaticOffsetData> &Table) {
Asm->OutStreamer->switchSection(MOFI->getDwarfAccelNamesSection());
auto *SectionBegin = Asm->createTempSymbol("names_begin");
Asm->OutStreamer->emitLabel(SectionBegin);
emitAppleAccelTable(Asm.get(), Table, "names", SectionBegin);
}
void DwarfStreamer::emitAppleObjc(
AccelTable<AppleAccelTableStaticOffsetData> &Table) {
Asm->OutStreamer->switchSection(MOFI->getDwarfAccelObjCSection());
auto *SectionBegin = Asm->createTempSymbol("objc_begin");
Asm->OutStreamer->emitLabel(SectionBegin);
emitAppleAccelTable(Asm.get(), Table, "objc", SectionBegin);
}
void DwarfStreamer::emitAppleTypes(
AccelTable<AppleAccelTableStaticTypeData> &Table) {
Asm->OutStreamer->switchSection(MOFI->getDwarfAccelTypesSection());
auto *SectionBegin = Asm->createTempSymbol("types_begin");
Asm->OutStreamer->emitLabel(SectionBegin);
emitAppleAccelTable(Asm.get(), Table, "types", SectionBegin);
}
/// Emit the swift_ast section stored in \p Buffers.
void DwarfStreamer::emitSwiftAST(StringRef Buffer) {
MCSection *SwiftASTSection = MOFI->getDwarfSwiftASTSection();
SwiftASTSection->setAlignment(Align(32));
MS->switchSection(SwiftASTSection);
MS->emitBytes(Buffer);
}
void DwarfStreamer::emitSwiftReflectionSection(
llvm::binaryformat::Swift5ReflectionSectionKind ReflSectionKind,
StringRef Buffer, uint32_t Alignment, uint32_t Size) {
MCSection *ReflectionSection =
MOFI->getSwift5ReflectionSection(ReflSectionKind);
if (ReflectionSection == nullptr)
return;
ReflectionSection->setAlignment(Align(Alignment));
MS->switchSection(ReflectionSection);
MS->emitBytes(Buffer);
}
void DwarfStreamer::emitDwarfDebugArangesTable(
const CompileUnit &Unit, const AddressRanges &LinkedRanges) {
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
// Make .debug_aranges to be current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfARangesSection());
// Emit Header.
MCSymbol *BeginLabel = Asm->createTempSymbol("Barange");
MCSymbol *EndLabel = Asm->createTempSymbol("Earange");
unsigned HeaderSize =
sizeof(int32_t) + // Size of contents (w/o this field
sizeof(int16_t) + // DWARF ARange version number
sizeof(int32_t) + // Offset of CU in the .debug_info section
sizeof(int8_t) + // Pointer Size (in bytes)
sizeof(int8_t); // Segment Size (in bytes)
unsigned TupleSize = AddressSize * 2;
unsigned Padding = offsetToAlignment(HeaderSize, Align(TupleSize));
Asm->emitLabelDifference(EndLabel, BeginLabel, 4); // Arange length
Asm->OutStreamer->emitLabel(BeginLabel);
Asm->emitInt16(dwarf::DW_ARANGES_VERSION); // Version number
Asm->emitInt32(Unit.getStartOffset()); // Corresponding unit's offset
Asm->emitInt8(AddressSize); // Address size
Asm->emitInt8(0); // Segment size
Asm->OutStreamer->emitFill(Padding, 0x0);
// Emit linked ranges.
for (const AddressRange &Range : LinkedRanges) {
MS->emitIntValue(Range.start(), AddressSize);
MS->emitIntValue(Range.end() - Range.start(), AddressSize);
}
// Emit terminator.
Asm->OutStreamer->emitIntValue(0, AddressSize);
Asm->OutStreamer->emitIntValue(0, AddressSize);
Asm->OutStreamer->emitLabel(EndLabel);
}
void DwarfStreamer::emitDwarfDebugRangesTableFragment(
const CompileUnit &Unit, const AddressRanges &LinkedRanges,
PatchLocation Patch) {
Patch.set(RangesSectionSize);
// Make .debug_ranges to be current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfRangesSection());
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
// Emit ranges.
uint64_t BaseAddress = 0;
if (std::optional<uint64_t> LowPC = Unit.getLowPc())
BaseAddress = *LowPC;
for (const AddressRange &Range : LinkedRanges) {
MS->emitIntValue(Range.start() - BaseAddress, AddressSize);
MS->emitIntValue(Range.end() - BaseAddress, AddressSize);
RangesSectionSize += AddressSize;
RangesSectionSize += AddressSize;
}
// Add the terminator entry.
MS->emitIntValue(0, AddressSize);
MS->emitIntValue(0, AddressSize);
RangesSectionSize += AddressSize;
RangesSectionSize += AddressSize;
}
MCSymbol *
DwarfStreamer::emitDwarfDebugRangeListHeader(const CompileUnit &Unit) {
if (Unit.getOrigUnit().getVersion() < 5)
return nullptr;
// Make .debug_rnglists to be current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfRnglistsSection());
MCSymbol *BeginLabel = Asm->createTempSymbol("Brnglists");
MCSymbol *EndLabel = Asm->createTempSymbol("Ernglists");
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
// Length
Asm->emitLabelDifference(EndLabel, BeginLabel, sizeof(uint32_t));
Asm->OutStreamer->emitLabel(BeginLabel);
RngListsSectionSize += sizeof(uint32_t);
// Version.
MS->emitInt16(5);
RngListsSectionSize += sizeof(uint16_t);
// Address size.
MS->emitInt8(AddressSize);
RngListsSectionSize++;
// Seg_size
MS->emitInt8(0);
RngListsSectionSize++;
// Offset entry count
MS->emitInt32(0);
RngListsSectionSize += sizeof(uint32_t);
return EndLabel;
}
void DwarfStreamer::emitDwarfDebugRangeListFragment(
const CompileUnit &Unit, const AddressRanges &LinkedRanges,
PatchLocation Patch) {
if (Unit.getOrigUnit().getVersion() < 5) {
emitDwarfDebugRangesTableFragment(Unit, LinkedRanges, Patch);
return;
}
emitDwarfDebugRngListsTableFragment(Unit, LinkedRanges, Patch);
}
void DwarfStreamer::emitDwarfDebugRangeListFooter(const CompileUnit &Unit,
MCSymbol *EndLabel) {
if (Unit.getOrigUnit().getVersion() < 5)
return;
// Make .debug_rnglists to be current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfRnglistsSection());
if (EndLabel != nullptr)
Asm->OutStreamer->emitLabel(EndLabel);
}
void DwarfStreamer::emitDwarfDebugRngListsTableFragment(
const CompileUnit &Unit, const AddressRanges &LinkedRanges,
PatchLocation Patch) {
Patch.set(RngListsSectionSize);
// Make .debug_rnglists to be current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfRnglistsSection());
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
for (const AddressRange &Range : LinkedRanges) {
// Emit type of entry.
MS->emitInt8(dwarf::DW_RLE_start_length);
RngListsSectionSize += 1;
// Emit start address.
MS->emitIntValue(Range.start(), AddressSize);
RngListsSectionSize += AddressSize;
// Emit length of the range.
RngListsSectionSize += MS->emitSLEB128IntValue(Range.end() - Range.start());
}
// Emit the terminator entry.
MS->emitInt8(dwarf::DW_RLE_end_of_list);
RngListsSectionSize += 1;
}
/// Emit debug locations(.debug_loc, .debug_loclists) header.
MCSymbol *DwarfStreamer::emitDwarfDebugLocListHeader(const CompileUnit &Unit) {
if (Unit.getOrigUnit().getVersion() < 5)
return nullptr;
// Make .debug_loclists the current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfLoclistsSection());
MCSymbol *BeginLabel = Asm->createTempSymbol("Bloclists");
MCSymbol *EndLabel = Asm->createTempSymbol("Eloclists");
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
// Length
Asm->emitLabelDifference(EndLabel, BeginLabel, sizeof(uint32_t));
Asm->OutStreamer->emitLabel(BeginLabel);
LocListsSectionSize += sizeof(uint32_t);
// Version.
MS->emitInt16(5);
LocListsSectionSize += sizeof(uint16_t);
// Address size.
MS->emitInt8(AddressSize);
LocListsSectionSize++;
// Seg_size
MS->emitInt8(0);
LocListsSectionSize++;
// Offset entry count
MS->emitInt32(0);
LocListsSectionSize += sizeof(uint32_t);
return EndLabel;
}
/// Emit debug locations(.debug_loc, .debug_loclists) fragment.
void DwarfStreamer::emitDwarfDebugLocListFragment(
const CompileUnit &Unit,
const DWARFLocationExpressionsVector &LinkedLocationExpression,
PatchLocation Patch) {
if (Unit.getOrigUnit().getVersion() < 5) {
emitDwarfDebugLocTableFragment(Unit, LinkedLocationExpression, Patch);
return;
}
emitDwarfDebugLocListsTableFragment(Unit, LinkedLocationExpression, Patch);
}
/// Emit debug locations(.debug_loc, .debug_loclists) footer.
void DwarfStreamer::emitDwarfDebugLocListFooter(const CompileUnit &Unit,
MCSymbol *EndLabel) {
if (Unit.getOrigUnit().getVersion() < 5)
return;
// Make .debug_loclists the current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfLoclistsSection());
if (EndLabel != nullptr)
Asm->OutStreamer->emitLabel(EndLabel);
}
/// Emit piece of .debug_loc for \p LinkedLocationExpression.
void DwarfStreamer::emitDwarfDebugLocTableFragment(
const CompileUnit &Unit,
const DWARFLocationExpressionsVector &LinkedLocationExpression,
PatchLocation Patch) {
Patch.set(LocSectionSize);
// Make .debug_loc to be current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfLocSection());
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
// Emit ranges.
uint64_t BaseAddress = 0;
if (std::optional<uint64_t> LowPC = Unit.getLowPc())
BaseAddress = *LowPC;
for (const DWARFLocationExpression &LocExpression :
LinkedLocationExpression) {
if (LocExpression.Range) {
MS->emitIntValue(LocExpression.Range->LowPC - BaseAddress, AddressSize);
MS->emitIntValue(LocExpression.Range->HighPC - BaseAddress, AddressSize);
LocSectionSize += AddressSize;
LocSectionSize += AddressSize;
}
Asm->OutStreamer->emitIntValue(LocExpression.Expr.size(), 2);
Asm->OutStreamer->emitBytes(StringRef(
(const char *)LocExpression.Expr.data(), LocExpression.Expr.size()));
LocSectionSize += LocExpression.Expr.size() + 2;
}
// Add the terminator entry.
MS->emitIntValue(0, AddressSize);
MS->emitIntValue(0, AddressSize);
LocSectionSize += AddressSize;
LocSectionSize += AddressSize;
}
/// Emit piece of .debug_loclists for \p LinkedLocationExpression.
void DwarfStreamer::emitDwarfDebugLocListsTableFragment(
const CompileUnit &Unit,
const DWARFLocationExpressionsVector &LinkedLocationExpression,
PatchLocation Patch) {
Patch.set(LocListsSectionSize);
// Make .debug_loclists the current section.
MS->switchSection(MC->getObjectFileInfo()->getDwarfLoclistsSection());
unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
for (const DWARFLocationExpression &LocExpression :
LinkedLocationExpression) {
if (LocExpression.Range) {
// Emit type of entry.
MS->emitInt8(dwarf::DW_LLE_start_length);
LocListsSectionSize += 1;
// Emit start address.
MS->emitIntValue(LocExpression.Range->LowPC, AddressSize);
LocListsSectionSize += AddressSize;
// Emit length of the range.
LocListsSectionSize += MS->emitSLEB128IntValue(
LocExpression.Range->HighPC - LocExpression.Range->LowPC);
} else {
// Emit type of entry.
MS->emitInt8(dwarf::DW_LLE_default_location);
LocListsSectionSize += 1;
}
LocListsSectionSize += MS->emitULEB128IntValue(LocExpression.Expr.size());
Asm->OutStreamer->emitBytes(StringRef(
(const char *)LocExpression.Expr.data(), LocExpression.Expr.size()));
LocListsSectionSize += LocExpression.Expr.size();
}
// Emit the terminator entry.
MS->emitInt8(dwarf::DW_LLE_end_of_list);
LocListsSectionSize += 1;
}
void DwarfStreamer::emitLineTableForUnit(MCDwarfLineTableParams Params,
StringRef PrologueBytes,
unsigned MinInstLength,
std::vector<DWARFDebugLine::Row> &Rows,
unsigned PointerSize) {
// Switch to the section where the table will be emitted into.
MS->switchSection(MC->getObjectFileInfo()->getDwarfLineSection());
MCSymbol *LineStartSym = MC->createTempSymbol();
MCSymbol *LineEndSym = MC->createTempSymbol();
// The first 4 bytes is the total length of the information for this
// compilation unit (not including these 4 bytes for the length).
Asm->emitLabelDifference(LineEndSym, LineStartSym, 4);
Asm->OutStreamer->emitLabel(LineStartSym);
// Copy Prologue.
MS->emitBytes(PrologueBytes);
LineSectionSize += PrologueBytes.size() + 4;
SmallString<128> EncodingBuffer;
raw_svector_ostream EncodingOS(EncodingBuffer);
if (Rows.empty()) {
// We only have the dummy entry, dsymutil emits an entry with a 0
// address in that case.
MCDwarfLineAddr::Encode(*MC, Params, std::numeric_limits<int64_t>::max(), 0,
EncodingOS);
MS->emitBytes(EncodingOS.str());
LineSectionSize += EncodingBuffer.size();
MS->emitLabel(LineEndSym);
return;
}
// Line table state machine fields
unsigned FileNum = 1;
unsigned LastLine = 1;
unsigned Column = 0;
unsigned IsStatement = 1;
unsigned Isa = 0;
uint64_t Address = -1ULL;
unsigned RowsSinceLastSequence = 0;
for (DWARFDebugLine::Row &Row : Rows) {
int64_t AddressDelta;
if (Address == -1ULL) {
MS->emitIntValue(dwarf::DW_LNS_extended_op, 1);
MS->emitULEB128IntValue(PointerSize + 1);
MS->emitIntValue(dwarf::DW_LNE_set_address, 1);
MS->emitIntValue(Row.Address.Address, PointerSize);
LineSectionSize += 2 + PointerSize + getULEB128Size(PointerSize + 1);
AddressDelta = 0;
} else {
AddressDelta = (Row.Address.Address - Address) / MinInstLength;
}
// FIXME: code copied and transformed from MCDwarf.cpp::EmitDwarfLineTable.
// We should find a way to share this code, but the current compatibility
// requirement with classic dsymutil makes it hard. Revisit that once this
// requirement is dropped.
if (FileNum != Row.File) {
FileNum = Row.File;
MS->emitIntValue(dwarf::DW_LNS_set_file, 1);
MS->emitULEB128IntValue(FileNum);
LineSectionSize += 1 + getULEB128Size(FileNum);
}
if (Column != Row.Column) {
Column = Row.Column;
MS->emitIntValue(dwarf::DW_LNS_set_column, 1);
MS->emitULEB128IntValue(Column);
LineSectionSize += 1 + getULEB128Size(Column);
}
// FIXME: We should handle the discriminator here, but dsymutil doesn't
// consider it, thus ignore it for now.
if (Isa != Row.Isa) {
Isa = Row.Isa;
MS->emitIntValue(dwarf::DW_LNS_set_isa, 1);
MS->emitULEB128IntValue(Isa);
LineSectionSize += 1 + getULEB128Size(Isa);
}
if (IsStatement != Row.IsStmt) {
IsStatement = Row.IsStmt;
MS->emitIntValue(dwarf::DW_LNS_negate_stmt, 1);
LineSectionSize += 1;
}
if (Row.BasicBlock) {
MS->emitIntValue(dwarf::DW_LNS_set_basic_block, 1);
LineSectionSize += 1;
}
if (Row.PrologueEnd) {
MS->emitIntValue(dwarf::DW_LNS_set_prologue_end, 1);
LineSectionSize += 1;
}
if (Row.EpilogueBegin) {
MS->emitIntValue(dwarf::DW_LNS_set_epilogue_begin, 1);
LineSectionSize += 1;
}
int64_t LineDelta = int64_t(Row.Line) - LastLine;
if (!Row.EndSequence) {
MCDwarfLineAddr::Encode(*MC, Params, LineDelta, AddressDelta, EncodingOS);
MS->emitBytes(EncodingOS.str());
LineSectionSize += EncodingBuffer.size();
EncodingBuffer.resize(0);
Address = Row.Address.Address;
LastLine = Row.Line;
RowsSinceLastSequence++;
} else {
if (LineDelta) {
MS->emitIntValue(dwarf::DW_LNS_advance_line, 1);
MS->emitSLEB128IntValue(LineDelta);
LineSectionSize += 1 + getSLEB128Size(LineDelta);
}
if (AddressDelta) {
MS->emitIntValue(dwarf::DW_LNS_advance_pc, 1);
MS->emitULEB128IntValue(AddressDelta);
LineSectionSize += 1 + getULEB128Size(AddressDelta);
}
MCDwarfLineAddr::Encode(*MC, Params, std::numeric_limits<int64_t>::max(),
0, EncodingOS);
MS->emitBytes(EncodingOS.str());
LineSectionSize += EncodingBuffer.size();
EncodingBuffer.resize(0);
Address = -1ULL;
LastLine = FileNum = IsStatement = 1;
RowsSinceLastSequence = Column = Isa = 0;
}
}
if (RowsSinceLastSequence) {
MCDwarfLineAddr::Encode(*MC, Params, std::numeric_limits<int64_t>::max(), 0,
EncodingOS);
MS->emitBytes(EncodingOS.str());
LineSectionSize += EncodingBuffer.size();
EncodingBuffer.resize(0);
}
MS->emitLabel(LineEndSym);
}
/// Copy the debug_line over to the updated binary while unobfuscating the file
/// names and directories.
void DwarfStreamer::translateLineTable(DataExtractor Data, uint64_t Offset) {
MS->switchSection(MC->getObjectFileInfo()->getDwarfLineSection());
StringRef Contents = Data.getData();
// We have to deconstruct the line table header, because it contains to
// length fields that will need to be updated when we change the length of
// the files and directories in there.
unsigned UnitLength = Data.getU32(&Offset);
uint64_t UnitEnd = Offset + UnitLength;
MCSymbol *BeginLabel = MC->createTempSymbol();
MCSymbol *EndLabel = MC->createTempSymbol();
unsigned Version = Data.getU16(&Offset);
if (Version > 5) {
warn("Unsupported line table version: dropping contents and not "
"unobfsucating line table.");
return;
}
Asm->emitLabelDifference(EndLabel, BeginLabel, 4);
Asm->OutStreamer->emitLabel(BeginLabel);
Asm->emitInt16(Version);
LineSectionSize += 6;
MCSymbol *HeaderBeginLabel = MC->createTempSymbol();
MCSymbol *HeaderEndLabel = MC->createTempSymbol();
Asm->emitLabelDifference(HeaderEndLabel, HeaderBeginLabel, 4);
Asm->OutStreamer->emitLabel(HeaderBeginLabel);
Offset += 4;
LineSectionSize += 4;
uint64_t AfterHeaderLengthOffset = Offset;
// Skip to the directories.
Offset += (Version >= 4) ? 5 : 4;
unsigned OpcodeBase = Data.getU8(&Offset);
Offset += OpcodeBase - 1;
Asm->OutStreamer->emitBytes(Contents.slice(AfterHeaderLengthOffset, Offset));
LineSectionSize += Offset - AfterHeaderLengthOffset;
// Offset points to the first directory.
while (const char *Dir = Data.getCStr(&Offset)) {
if (Dir[0] == 0)
break;
StringRef Translated = Translator(Dir);
Asm->OutStreamer->emitBytes(Translated);
Asm->emitInt8(0);
LineSectionSize += Translated.size() + 1;
}
Asm->emitInt8(0);
LineSectionSize += 1;
while (const char *File = Data.getCStr(&Offset)) {
if (File[0] == 0)
break;
StringRef Translated = Translator(File);
Asm->OutStreamer->emitBytes(Translated);
Asm->emitInt8(0);
LineSectionSize += Translated.size() + 1;
uint64_t OffsetBeforeLEBs = Offset;
Asm->emitULEB128(Data.getULEB128(&Offset));
Asm->emitULEB128(Data.getULEB128(&Offset));
Asm->emitULEB128(Data.getULEB128(&Offset));
LineSectionSize += Offset - OffsetBeforeLEBs;
}
Asm->emitInt8(0);
LineSectionSize += 1;
Asm->OutStreamer->emitLabel(HeaderEndLabel);
// Copy the actual line table program over.
Asm->OutStreamer->emitBytes(Contents.slice(Offset, UnitEnd));
LineSectionSize += UnitEnd - Offset;
Asm->OutStreamer->emitLabel(EndLabel);
Offset = UnitEnd;
}
/// Emit the pubnames or pubtypes section contribution for \p
/// Unit into \p Sec. The data is provided in \p Names.
void DwarfStreamer::emitPubSectionForUnit(
MCSection *Sec, StringRef SecName, const CompileUnit &Unit,
const std::vector<CompileUnit::AccelInfo> &Names) {
if (Names.empty())
return;
// Start the dwarf pubnames section.
Asm->OutStreamer->switchSection(Sec);
MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + SecName + "_begin");
MCSymbol *EndLabel = Asm->createTempSymbol("pub" + SecName + "_end");
bool HeaderEmitted = false;
// Emit the pubnames for this compilation unit.
for (const auto &Name : Names) {
if (Name.SkipPubSection)
continue;
if (!HeaderEmitted) {
// Emit the header.
Asm->emitLabelDifference(EndLabel, BeginLabel, 4); // Length
Asm->OutStreamer->emitLabel(BeginLabel);
Asm->emitInt16(dwarf::DW_PUBNAMES_VERSION); // Version
Asm->emitInt32(Unit.getStartOffset()); // Unit offset
Asm->emitInt32(Unit.getNextUnitOffset() - Unit.getStartOffset()); // Size
HeaderEmitted = true;
}
Asm->emitInt32(Name.Die->getOffset());
// Emit the string itself.
Asm->OutStreamer->emitBytes(Name.Name.getString());
// Emit a null terminator.
Asm->emitInt8(0);
}
if (!HeaderEmitted)
return;
Asm->emitInt32(0); // End marker.
Asm->OutStreamer->emitLabel(EndLabel);
}
/// Emit .debug_pubnames for \p Unit.
void DwarfStreamer::emitPubNamesForUnit(const CompileUnit &Unit) {
emitPubSectionForUnit(MC->getObjectFileInfo()->getDwarfPubNamesSection(),
"names", Unit, Unit.getPubnames());
}
/// Emit .debug_pubtypes for \p Unit.
void DwarfStreamer::emitPubTypesForUnit(const CompileUnit &Unit) {
emitPubSectionForUnit(MC->getObjectFileInfo()->getDwarfPubTypesSection(),
"types", Unit, Unit.getPubtypes());
}
/// Emit a CIE into the debug_frame section.
void DwarfStreamer::emitCIE(StringRef CIEBytes) {
MS->switchSection(MC->getObjectFileInfo()->getDwarfFrameSection());
MS->emitBytes(CIEBytes);
FrameSectionSize += CIEBytes.size();
}
/// Emit a FDE into the debug_frame section. \p FDEBytes
/// contains the FDE data without the length, CIE offset and address
/// which will be replaced with the parameter values.
void DwarfStreamer::emitFDE(uint32_t CIEOffset, uint32_t AddrSize,
uint64_t Address, StringRef FDEBytes) {
MS->switchSection(MC->getObjectFileInfo()->getDwarfFrameSection());
MS->emitIntValue(FDEBytes.size() + 4 + AddrSize, 4);
MS->emitIntValue(CIEOffset, 4);
MS->emitIntValue(Address, AddrSize);
MS->emitBytes(FDEBytes);
FrameSectionSize += FDEBytes.size() + 8 + AddrSize;
}
void DwarfStreamer::emitMacroTables(DWARFContext *Context,
const Offset2UnitMap &UnitMacroMap,
OffsetsStringPool &StringPool) {
assert(Context != nullptr && "Empty DWARF context");
// Check for .debug_macinfo table.
if (const DWARFDebugMacro *Table = Context->getDebugMacinfo()) {
MS->switchSection(MC->getObjectFileInfo()->getDwarfMacinfoSection());
emitMacroTableImpl(Table, UnitMacroMap, StringPool, MacInfoSectionSize);
}
// Check for .debug_macro table.
if (const DWARFDebugMacro *Table = Context->getDebugMacro()) {
MS->switchSection(MC->getObjectFileInfo()->getDwarfMacroSection());
emitMacroTableImpl(Table, UnitMacroMap, StringPool, MacroSectionSize);
}
}
void DwarfStreamer::emitMacroTableImpl(const DWARFDebugMacro *MacroTable,
const Offset2UnitMap &UnitMacroMap,
OffsetsStringPool &StringPool,
uint64_t &OutOffset) {
bool DefAttributeIsReported = false;
bool UndefAttributeIsReported = false;
bool ImportAttributeIsReported = false;
for (const DWARFDebugMacro::MacroList &List : MacroTable->MacroLists) {
Offset2UnitMap::const_iterator UnitIt = UnitMacroMap.find(List.Offset);
if (UnitIt == UnitMacroMap.end()) {
warn(formatv(
"couldn`t find compile unit for the macro table with offset = {0:x}",
List.Offset));
continue;
}
// Skip macro table if the unit was not cloned.
DIE *OutputUnitDIE = UnitIt->second->getOutputUnitDIE();
if (OutputUnitDIE == nullptr)
continue;
// Update macro attribute of cloned compile unit with the proper offset to
// the macro table.
bool hasDWARFv5Header = false;
for (auto &V : OutputUnitDIE->values()) {
if (V.getAttribute() == dwarf::DW_AT_macro_info) {
V = DIEValue(V.getAttribute(), V.getForm(), DIEInteger(OutOffset));
break;
} else if (V.getAttribute() == dwarf::DW_AT_macros) {
hasDWARFv5Header = true;
V = DIEValue(V.getAttribute(), V.getForm(), DIEInteger(OutOffset));
break;
}
}
// Write DWARFv5 header.
if (hasDWARFv5Header) {
// Write header version.
MS->emitIntValue(List.Header.Version, sizeof(List.Header.Version));
OutOffset += sizeof(List.Header.Version);
uint8_t Flags = List.Header.Flags;
// Check for OPCODE_OPERANDS_TABLE.
if (Flags &
DWARFDebugMacro::HeaderFlagMask::MACRO_OPCODE_OPERANDS_TABLE) {
Flags &= ~DWARFDebugMacro::HeaderFlagMask::MACRO_OPCODE_OPERANDS_TABLE;
warn("opcode_operands_table is not supported yet.");
}
// Check for DEBUG_LINE_OFFSET.
std::optional<uint64_t> StmtListOffset;
if (Flags & DWARFDebugMacro::HeaderFlagMask::MACRO_DEBUG_LINE_OFFSET) {
// Get offset to the line table from the cloned compile unit.
for (auto &V : OutputUnitDIE->values()) {
if (V.getAttribute() == dwarf::DW_AT_stmt_list) {
StmtListOffset = V.getDIEInteger().getValue();
break;
}
}
if (!StmtListOffset) {
Flags &= ~DWARFDebugMacro::HeaderFlagMask::MACRO_DEBUG_LINE_OFFSET;
warn("couldn`t find line table for macro table.");
}
}
// Write flags.
MS->emitIntValue(Flags, sizeof(Flags));
OutOffset += sizeof(Flags);
// Write offset to line table.
if (StmtListOffset) {
MS->emitIntValue(*StmtListOffset, List.Header.getOffsetByteSize());
OutOffset += List.Header.getOffsetByteSize();
}
}
// Write macro entries.
for (const DWARFDebugMacro::Entry &MacroEntry : List.Macros) {
if (MacroEntry.Type == 0) {
OutOffset += MS->emitULEB128IntValue(MacroEntry.Type);
continue;
}
uint8_t MacroType = MacroEntry.Type;
switch (MacroType) {
default: {
bool HasVendorSpecificExtension =
(!hasDWARFv5Header && MacroType == dwarf::DW_MACINFO_vendor_ext) ||
(hasDWARFv5Header && (MacroType >= dwarf::DW_MACRO_lo_user &&
MacroType <= dwarf::DW_MACRO_hi_user));
if (HasVendorSpecificExtension) {
// Write macinfo type.
MS->emitIntValue(MacroType, 1);
OutOffset++;
// Write vendor extension constant.
OutOffset += MS->emitULEB128IntValue(MacroEntry.ExtConstant);
// Write vendor extension string.
StringRef String = MacroEntry.ExtStr;
MS->emitBytes(String);
MS->emitIntValue(0, 1);
OutOffset += String.size() + 1;
} else
warn("unknown macro type. skip.");
} break;
// debug_macro and debug_macinfo share some common encodings.
// DW_MACRO_define == DW_MACINFO_define
// DW_MACRO_undef == DW_MACINFO_undef
// DW_MACRO_start_file == DW_MACINFO_start_file
// DW_MACRO_end_file == DW_MACINFO_end_file
// For readibility/uniformity we are using DW_MACRO_*.
case dwarf::DW_MACRO_define:
case dwarf::DW_MACRO_undef: {
// Write macinfo type.
MS->emitIntValue(MacroType, 1);
OutOffset++;
// Write source line.
OutOffset += MS->emitULEB128IntValue(MacroEntry.Line);
// Write macro string.
StringRef String = MacroEntry.MacroStr;
MS->emitBytes(String);
MS->emitIntValue(0, 1);
OutOffset += String.size() + 1;
} break;
case dwarf::DW_MACRO_define_strp:
case dwarf::DW_MACRO_undef_strp:
case dwarf::DW_MACRO_define_strx:
case dwarf::DW_MACRO_undef_strx: {
assert(UnitIt->second->getOrigUnit().getVersion() >= 5);
// DW_MACRO_*_strx forms are not supported currently.
// Convert to *_strp.
switch (MacroType) {
case dwarf::DW_MACRO_define_strx: {
MacroType = dwarf::DW_MACRO_define_strp;
if (!DefAttributeIsReported) {
warn("DW_MACRO_define_strx unsupported yet. Convert to "
"DW_MACRO_define_strp.");
DefAttributeIsReported = true;
}
} break;
case dwarf::DW_MACRO_undef_strx: {
MacroType = dwarf::DW_MACRO_undef_strp;
if (!UndefAttributeIsReported) {
warn("DW_MACRO_undef_strx unsupported yet. Convert to "
"DW_MACRO_undef_strp.");
UndefAttributeIsReported = true;
}
} break;
default:
// Nothing to do.
break;
}
// Write macinfo type.
MS->emitIntValue(MacroType, 1);
OutOffset++;
// Write source line.
OutOffset += MS->emitULEB128IntValue(MacroEntry.Line);
// Write macro string.
DwarfStringPoolEntryRef EntryRef =
StringPool.getEntry(MacroEntry.MacroStr);
MS->emitIntValue(EntryRef.getOffset(), List.Header.getOffsetByteSize());
OutOffset += List.Header.getOffsetByteSize();
break;
}
case dwarf::DW_MACRO_start_file: {
// Write macinfo type.
MS->emitIntValue(MacroType, 1);
OutOffset++;
// Write source line.
OutOffset += MS->emitULEB128IntValue(MacroEntry.Line);
// Write source file id.
OutOffset += MS->emitULEB128IntValue(MacroEntry.File);
} break;
case dwarf::DW_MACRO_end_file: {
// Write macinfo type.
MS->emitIntValue(MacroType, 1);
OutOffset++;
} break;
case dwarf::DW_MACRO_import:
case dwarf::DW_MACRO_import_sup: {
if (!ImportAttributeIsReported) {
warn("DW_MACRO_import and DW_MACRO_import_sup are unsupported yet. "
"remove.");
ImportAttributeIsReported = true;
}
} break;
}
}
}
}
} // namespace llvm
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