DWARFListTable.cpp

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//===- DWARFListTable.cpp ---------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "llvm/DebugInfo/DWARF/DWARFListTable.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FormatAdapters.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/raw_ostream.h"
 
using namespace llvm;
 
Error DWARFListTableHeader::extract(DWARFDataExtractor Data,
                                    uint64_t *OffsetPtr) {
  HeaderOffset = *OffsetPtr;
  Error Err = Error::success();
 
  std::tie(HeaderData.Length, Format) = Data.getInitialLength(OffsetPtr, &Err);
  if (Err)
    return createStringError(
        errc::invalid_argument, "parsing %s table at offset 0x%" PRIx64 ": %s",
        SectionName.data(), HeaderOffset, toString(std::move(Err)).c_str());
 
  uint8_t OffsetByteSize = Format == dwarf::DWARF64 ? 8 : 4;
  uint64_t FullLength =
      HeaderData.Length + dwarf::getUnitLengthFieldByteSize(Format);
  if (FullLength < getHeaderSize(Format))
    return createStringError(errc::invalid_argument,
                       "%s table at offset 0x%" PRIx64
                       " has too small length (0x%" PRIx64
                       ") to contain a complete header",
                       SectionName.data(), HeaderOffset, FullLength);
  assert(FullLength == length() && "Inconsistent calculation of length.");
  uint64_t End = HeaderOffset + FullLength;
  if (!Data.isValidOffsetForDataOfSize(HeaderOffset, FullLength))
    return createStringError(errc::invalid_argument,
                       "section is not large enough to contain a %s table "
                       "of length 0x%" PRIx64 " at offset 0x%" PRIx64,
                       SectionName.data(), FullLength, HeaderOffset);
 
  HeaderData.Version = Data.getU16(OffsetPtr);
  HeaderData.AddrSize = Data.getU8(OffsetPtr);
  HeaderData.SegSize = Data.getU8(OffsetPtr);
  HeaderData.OffsetEntryCount = Data.getU32(OffsetPtr);
 
  // Perform basic validation of the remaining header fields.
  if (HeaderData.Version < 5 || HeaderData.Version > 6)
    return createStringError(errc::invalid_argument,
                       "unrecognised %s table version %" PRIu16
                       " in table at offset 0x%" PRIx64,
                       SectionName.data(), HeaderData.Version, HeaderOffset);
  if (Error SizeErr = DWARFContext::checkAddressSizeSupported(
          HeaderData.AddrSize, errc::not_supported,
          "%s table at offset 0x%" PRIx64, SectionName.data(), HeaderOffset))
    return SizeErr;
  if (HeaderData.SegSize != 0)
    return createStringError(errc::not_supported,
                       "%s table at offset 0x%" PRIx64
                       " has unsupported segment selector size %" PRIu8,
                       SectionName.data(), HeaderOffset, HeaderData.SegSize);
  if (End < HeaderOffset + getHeaderSize(Format) +
                HeaderData.OffsetEntryCount * OffsetByteSize)
    return createStringError(errc::invalid_argument,
        "%s table at offset 0x%" PRIx64 " has more offset entries (%" PRIu32
        ") than there is space for",
        SectionName.data(), HeaderOffset, HeaderData.OffsetEntryCount);
  Data.setAddressSize(HeaderData.AddrSize);
  *OffsetPtr += HeaderData.OffsetEntryCount * OffsetByteSize;
  return Error::success();
}
 
void DWARFListTableHeader::dump(DataExtractor Data, raw_ostream &OS,
                                DIDumpOptions DumpOpts) const {
  if (DumpOpts.Verbose)
    OS << formatv("{0:x8}: ", HeaderOffset);
  int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(Format);
  OS << formatv("{0} list header: length = 0x{1:x-}", ListTypeString.data(),
                fmt_align(HeaderData.Length, AlignStyle::Right, OffsetDumpWidth,
                          '0'))
     << ", format = " << dwarf::FormatString(Format)
     << formatv(", version = {0:x4}, addr_size = {1:x2}"
                ", seg_size = {2:x2}"
                ", offset_entry_count = {3:x8}\n",
                HeaderData.Version, HeaderData.AddrSize, HeaderData.SegSize,
                HeaderData.OffsetEntryCount);
 
  if (HeaderData.OffsetEntryCount > 0) {
    OS << "offsets: [";
    for (uint32_t I = 0; I < HeaderData.OffsetEntryCount; ++I) {
      auto Off = *getOffsetEntry(Data, I);
      OS << formatv("\n0x{0:x-}",
                    fmt_align(Off, AlignStyle::Right, OffsetDumpWidth, '0'));
      if (DumpOpts.Verbose)
        OS << formatv(" => {0:x8}", Off + HeaderOffset + getHeaderSize(Format));
    }
    OS << "\n]\n";
  }
}
 
uint64_t DWARFListTableHeader::length() const {
  if (HeaderData.Length == 0)
    return 0;
  return HeaderData.Length + dwarf::getUnitLengthFieldByteSize(Format);
}