blob: 838e1c9a10be654a53c850efb4fe370ae7643cc2 [file] [log] [blame]
//===- llvm/CodeGen/DwarfFile.cpp - Dwarf Debug Framework -----------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "DwarfFile.h"
#include "DwarfCompileUnit.h"
#include "DwarfDebug.h"
#include "DwarfUnit.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/Metadata.h"
#include "llvm/MC/MCStreamer.h"
#include <algorithm>
#include <cstdint>
using namespace llvm;
DwarfFile::DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA)
: Asm(AP), Abbrevs(AbbrevAllocator), StrPool(DA, *Asm, Pref) {}
void DwarfFile::addUnit(std::unique_ptr<DwarfCompileUnit> U) {
// Emit the various dwarf units to the unit section USection with
// the abbreviations going into ASection.
void DwarfFile::emitUnits(bool UseOffsets) {
for (const auto &TheU : CUs)
emitUnit(TheU.get(), UseOffsets);
void DwarfFile::emitUnit(DwarfUnit *TheU, bool UseOffsets) {
if (TheU->getCUNode()->isDebugDirectivesOnly())
MCSection *S = TheU->getSection();
if (!S)
// Skip CUs that ended up not being needed (split CUs that were abandoned
// because they added no information beyond the non-split CU)
if (llvm::empty(TheU->getUnitDie().values()))
if (MCSymbol *EndLabel = TheU->getEndLabel())
// Compute the size and offset for each DIE.
void DwarfFile::computeSizeAndOffsets() {
// Offset from the first CU in the debug info section is 0 initially.
uint64_t SecOffset = 0;
// Iterate over each compile unit and set the size and offsets for each
// DIE within each compile unit. All offsets are CU relative.
for (const auto &TheU : CUs) {
if (TheU->getCUNode()->isDebugDirectivesOnly())
// Skip CUs that ended up not being needed (split CUs that were abandoned
// because they added no information beyond the non-split CU)
if (llvm::empty(TheU->getUnitDie().values()))
SecOffset += computeSizeAndOffsetsForUnit(TheU.get());
if (SecOffset > UINT32_MAX && !Asm->isDwarf64())
report_fatal_error("The generated debug information is too large "
"for the 32-bit DWARF format.");
unsigned DwarfFile::computeSizeAndOffsetsForUnit(DwarfUnit *TheU) {
// CU-relative offset is reset to 0 here.
unsigned Offset = Asm->getUnitLengthFieldByteSize() + // Length of Unit Info
TheU->getHeaderSize(); // Unit-specific headers
// The return value here is CU-relative, after laying out
// all of the CU DIE.
return computeSizeAndOffset(TheU->getUnitDie(), Offset);
// Compute the size and offset of a DIE. The offset is relative to start of the
// CU. It returns the offset after laying out the DIE.
unsigned DwarfFile::computeSizeAndOffset(DIE &Die, unsigned Offset) {
return Die.computeOffsetsAndAbbrevs(Asm, Abbrevs, Offset);
void DwarfFile::emitAbbrevs(MCSection *Section) { Abbrevs.Emit(Asm, Section); }
// Emit strings into a string section.
void DwarfFile::emitStrings(MCSection *StrSection, MCSection *OffsetSection,
bool UseRelativeOffsets) {
StrPool.emit(*Asm, StrSection, OffsetSection, UseRelativeOffsets);
bool DwarfFile::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
auto &ScopeVars = ScopeVariables[LS];
const DILocalVariable *DV = Var->getVariable();
if (unsigned ArgNum = DV->getArg()) {
auto Cached = ScopeVars.Args.find(ArgNum);
if (Cached == ScopeVars.Args.end())
ScopeVars.Args[ArgNum] = Var;
else {
return false;
} else {
return true;
void DwarfFile::addScopeLabel(LexicalScope *LS, DbgLabel *Label) {
SmallVectorImpl<DbgLabel *> &Labels = ScopeLabels[LS];
std::pair<uint32_t, RangeSpanList *>
DwarfFile::addRange(const DwarfCompileUnit &CU, SmallVector<RangeSpan, 2> R) {
RangeSpanList{Asm->createTempSymbol("debug_ranges"), &CU, std::move(R)});
return std::make_pair(CURangeLists.size() - 1, &CURangeLists.back());