diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp new file mode 100644 index 0000000..737ee54 --- /dev/null +++ b/contrib/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp @@ -0,0 +1,156 @@ +//===-- llvm/CodeGen/DwarfFile.cpp - Dwarf Debug Framework ----------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "DwarfFile.h" + +#include "DwarfDebug.h" +#include "DwarfUnit.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/Support/LEB128.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/Target/TargetLoweringObjectFile.h" + +namespace llvm { +DwarfFile::DwarfFile(AsmPrinter *AP, StringRef Pref, BumpPtrAllocator &DA) + : Asm(AP), StrPool(DA, *Asm, Pref) {} + +DwarfFile::~DwarfFile() {} + +// Define a unique number for the abbreviation. +// +void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) { + // Check the set for priors. + DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev); + + // If it's newly added. + if (InSet == &Abbrev) { + // Add to abbreviation list. + Abbreviations.push_back(&Abbrev); + + // Assign the vector position + 1 as its number. + Abbrev.setNumber(Abbreviations.size()); + } else { + // Assign existing abbreviation number. + Abbrev.setNumber(InSet->getNumber()); + } +} + +void DwarfFile::addUnit(std::unique_ptr<DwarfUnit> U) { + CUs.push_back(std::move(U)); +} + +// Emit the various dwarf units to the unit section USection with +// the abbreviations going into ASection. +void DwarfFile::emitUnits(DwarfDebug *DD, const MCSymbol *ASectionSym) { + for (const auto &TheU : CUs) { + DIE &Die = TheU->getUnitDie(); + const MCSection *USection = TheU->getSection(); + Asm->OutStreamer.SwitchSection(USection); + + // Emit the compile units header. + Asm->OutStreamer.EmitLabel(TheU->getLabelBegin()); + + // Emit size of content not including length itself + Asm->OutStreamer.AddComment("Length of Unit"); + Asm->EmitInt32(TheU->getHeaderSize() + Die.getSize()); + + TheU->emitHeader(ASectionSym); + + DD->emitDIE(Die); + Asm->OutStreamer.EmitLabel(TheU->getLabelEnd()); + } +} +// Compute the size and offset for each DIE. +void DwarfFile::computeSizeAndOffsets() { + // Offset from the first CU in the debug info section is 0 initially. + unsigned 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) { + TheU->setDebugInfoOffset(SecOffset); + + // CU-relative offset is reset to 0 here. + unsigned Offset = sizeof(int32_t) + // Length of Unit Info + TheU->getHeaderSize(); // Unit-specific headers + + // EndOffset here is CU-relative, after laying out + // all of the CU DIE. + unsigned EndOffset = computeSizeAndOffset(TheU->getUnitDie(), Offset); + SecOffset += EndOffset; + } +} +// 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) { + // Record the abbreviation. + assignAbbrevNumber(Die.getAbbrev()); + + // Get the abbreviation for this DIE. + const DIEAbbrev &Abbrev = Die.getAbbrev(); + + // Set DIE offset + Die.setOffset(Offset); + + // Start the size with the size of abbreviation code. + Offset += getULEB128Size(Die.getAbbrevNumber()); + + const SmallVectorImpl<DIEValue *> &Values = Die.getValues(); + const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData(); + + // Size the DIE attribute values. + for (unsigned i = 0, N = Values.size(); i < N; ++i) + // Size attribute value. + Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm()); + + // Get the children. + const auto &Children = Die.getChildren(); + + // Size the DIE children if any. + if (!Children.empty()) { + assert(Abbrev.hasChildren() && "Children flag not set"); + + for (auto &Child : Children) + Offset = computeSizeAndOffset(*Child, Offset); + + // End of children marker. + Offset += sizeof(int8_t); + } + + Die.setSize(Offset - Die.getOffset()); + return Offset; +} +void DwarfFile::emitAbbrevs(const MCSection *Section) { + // Check to see if it is worth the effort. + if (!Abbreviations.empty()) { + // Start the debug abbrev section. + Asm->OutStreamer.SwitchSection(Section); + + // For each abbrevation. + for (const DIEAbbrev *Abbrev : Abbreviations) { + // Emit the abbrevations code (base 1 index.) + Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code"); + + // Emit the abbreviations data. + Abbrev->Emit(Asm); + } + + // Mark end of abbreviations. + Asm->EmitULEB128(0, "EOM(3)"); + } +} + +// Emit strings into a string section. +void DwarfFile::emitStrings(const MCSection *StrSection, + const MCSection *OffsetSection, + const MCSymbol *StrSecSym) { + StrPool.emit(*Asm, StrSection, OffsetSection, StrSecSym); +} +} |