lib/DebugInfo/DWARFContext.cpp

//===-- DWARFContext.cpp --------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "DWARFContext.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
using namespace dwarf;

void DWARFContext::dump(raw_ostream &OS) {
  OS << ".debug_abbrev contents:\n";
  getDebugAbbrev()->dump(OS);

  OS << "\n.debug_info contents:\n";
  for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i)
    getCompileUnitAtIndex(i)->dump(OS);

  OS << "\n.debug_aranges contents:\n";
  DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
  uint32_t offset = 0;
  DWARFDebugArangeSet set;
  while (set.extract(arangesData, &offset))
    set.dump(OS);

  OS << "\n.debug_lines contents:\n";
  for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) {
    DWARFCompileUnit *cu = getCompileUnitAtIndex(i);
    unsigned stmtOffset =
      cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
                                                           -1U);
    if (stmtOffset != -1U) {
      DataExtractor lineData(getLineSection(), isLittleEndian(),
                             cu->getAddressByteSize());
      DWARFDebugLine::DumpingState state(OS);
      DWARFDebugLine::parseStatementTable(lineData, &stmtOffset, state);
    }
  }

  OS << "\n.debug_str contents:\n";
  DataExtractor strData(getStringSection(), isLittleEndian(), 0);
  offset = 0;
  uint32_t lastOffset = 0;
  while (const char *s = strData.getCStr(&offset)) {
    OS << format("0x%8.8x: \"%s\"\n", lastOffset, s);
    lastOffset = offset;
  }
}

const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
  if (Abbrev)
    return Abbrev.get();

  DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);

  Abbrev.reset(new DWARFDebugAbbrev());
  Abbrev->parse(abbrData);
  return Abbrev.get();
}

const DWARFDebugAranges *DWARFContext::getDebugAranges() {
  if (Aranges)
    return Aranges.get();

  DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);

  Aranges.reset(new DWARFDebugAranges());
  Aranges->extract(arangesData);
  if (Aranges->isEmpty()) // No aranges in file, generate them from the DIEs.
    Aranges->generate(this);
  return Aranges.get();
}

const DWARFDebugLine::LineTable *
DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
  if (!Line)
    Line.reset(new DWARFDebugLine());

  unsigned stmtOffset =
    cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
                                                         -1U);
  if (stmtOffset == -1U)
    return 0; // No line table for this compile unit.

  // See if the line table is cached.
  if (const DWARFDebugLine::LineTable *lt = Line->getLineTable(stmtOffset))
    return lt;

  // We have to parse it first.
  DataExtractor lineData(getLineSection(), isLittleEndian(),
                         cu->getAddressByteSize());
  return Line->getOrParseLineTable(lineData, stmtOffset);
}

void DWARFContext::parseCompileUnits() {
  uint32_t offset = 0;
  const DataExtractor &debug_info_data = DataExtractor(getInfoSection(),
                                                       isLittleEndian(), 0);
  while (debug_info_data.isValidOffset(offset)) {
    CUs.push_back(DWARFCompileUnit(*this));
    if (!CUs.back().extract(debug_info_data, &offset)) {
      CUs.pop_back();
      break;
    }

    offset = CUs.back().getNextCompileUnitOffset();
  }
}