lib/DebugInfo/DWARF/DWARFDebugLoc.cpp

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

#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cinttypes>
#include <cstdint>

using namespace llvm;

void DWARFDebugLoc::dump(raw_ostream &OS) const {
  for (const LocationList &L : Locations) {
    OS << format("0x%8.8x: ", L.Offset);
    const unsigned Indent = 12;
    for (const Entry &E : L.Entries) {
      if (&E != L.Entries.begin())
        OS.indent(Indent);
      OS << "Beginning address offset: " << format("0x%016" PRIx64, E.Begin)
         << '\n';
      OS.indent(Indent) << "   Ending address offset: "
                        << format("0x%016" PRIx64, E.End) << '\n';
      OS.indent(Indent) << "    Location description: ";
      for (unsigned char Loc : E.Loc) {
        OS << format("%2.2x ", Loc);
      }
      OS << "\n\n";
    }
  }
}

void DWARFDebugLoc::parse(const DWARFDataExtractor &data) {
  uint32_t Offset = 0;
  while (data.isValidOffset(Offset+data.getAddressSize()-1)) {
    Locations.resize(Locations.size() + 1);
    LocationList &Loc = Locations.back();
    Loc.Offset = Offset;
    // 2.6.2 Location Lists
    // A location list entry consists of:
    while (true) {
      // A beginning and ending address offsets.
      Entry E;
      E.Begin = data.getRelocatedAddress(&Offset);
      E.End = data.getRelocatedAddress(&Offset);

      // The end of any given location list is marked by an end of list entry,
      // which consists of a 0 for the beginning address offset and a 0 for the
      // ending address offset.
      if (E.Begin == 0 && E.End == 0)
        break;

      unsigned Bytes = data.getU16(&Offset);
      // A single location description describing the location of the object...
      StringRef str = data.getData().substr(Offset, Bytes);
      Offset += Bytes;
      E.Loc.append(str.begin(), str.end());
      Loc.Entries.push_back(std::move(E));
    }
  }
  if (data.isValidOffset(Offset))
    errs() << "error: failed to consume entire .debug_loc section\n";
}

void DWARFDebugLocDWO::parse(DataExtractor data) {
  uint32_t Offset = 0;
  while (data.isValidOffset(Offset)) {
    Locations.resize(Locations.size() + 1);
    LocationList &Loc = Locations.back();
    Loc.Offset = Offset;
    dwarf::LocationListEntry Kind;
    while ((Kind = static_cast<dwarf::LocationListEntry>(
                data.getU8(&Offset))) != dwarf::DW_LLE_end_of_list) {

      if (Kind != dwarf::DW_LLE_startx_length) {
        errs() << "error: dumping support for LLE of kind " << (int)Kind
               << " not implemented\n";
        return;
      }

      Entry E;

      E.Start = data.getULEB128(&Offset);
      E.Length = data.getU32(&Offset);

      unsigned Bytes = data.getU16(&Offset);
      // A single location description describing the location of the object...
      StringRef str = data.getData().substr(Offset, Bytes);
      Offset += Bytes;
      E.Loc.resize(str.size());
      std::copy(str.begin(), str.end(), E.Loc.begin());

      Loc.Entries.push_back(std::move(E));
    }
  }
}

void DWARFDebugLocDWO::dump(raw_ostream &OS) const {
  for (const LocationList &L : Locations) {
    OS << format("0x%8.8x: ", L.Offset);
    const unsigned Indent = 12;
    for (const Entry &E : L.Entries) {
      if (&E != L.Entries.begin())
        OS.indent(Indent);
      OS << "Beginning address index: " << E.Start << '\n';
      OS.indent(Indent) << "                 Length: " << E.Length << '\n';
      OS.indent(Indent) << "   Location description: ";
      for (unsigned char Loc : E.Loc)
        OS << format("%2.2x ", Loc);
      OS << "\n\n";
    }
  }
}