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 000000000000..737ee54f94b5 --- /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); +} +}  | 
