1//===- DWARFListTable.cpp ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/DebugInfo/DWARF/DWARFListTable.h"
10#include "llvm/BinaryFormat/Dwarf.h"
11#include "llvm/Support/Errc.h"
12#include "llvm/Support/Error.h"
13#include "llvm/Support/Format.h"
14#include "llvm/Support/raw_ostream.h"
15
16using namespace llvm;
17
18Error DWARFListTableHeader::extract(DWARFDataExtractor Data,
19                                    uint64_t *OffsetPtr) {
20  HeaderOffset = *OffsetPtr;
21  Error Err = Error::success();
22
23  std::tie(HeaderData.Length, Format) = Data.getInitialLength(OffsetPtr, &Err);
24  if (Err)
25    return createStringError(
26        errc::invalid_argument, "parsing %s table at offset 0x%" PRIx64 ": %s",
27        SectionName.data(), HeaderOffset, toString(std::move(Err)).c_str());
28
29  uint8_t OffsetByteSize = Format == dwarf::DWARF64 ? 8 : 4;
30  uint64_t FullLength =
31      HeaderData.Length + dwarf::getUnitLengthFieldByteSize(Format);
32  if (FullLength < getHeaderSize(Format))
33    return createStringError(errc::invalid_argument,
34                       "%s table at offset 0x%" PRIx64
35                       " has too small length (0x%" PRIx64
36                       ") to contain a complete header",
37                       SectionName.data(), HeaderOffset, FullLength);
38  assert(FullLength == length() && "Inconsistent calculation of length.");
39  uint64_t End = HeaderOffset + FullLength;
40  if (!Data.isValidOffsetForDataOfSize(HeaderOffset, FullLength))
41    return createStringError(errc::invalid_argument,
42                       "section is not large enough to contain a %s table "
43                       "of length 0x%" PRIx64 " at offset 0x%" PRIx64,
44                       SectionName.data(), FullLength, HeaderOffset);
45
46  HeaderData.Version = Data.getU16(OffsetPtr);
47  HeaderData.AddrSize = Data.getU8(OffsetPtr);
48  HeaderData.SegSize = Data.getU8(OffsetPtr);
49  HeaderData.OffsetEntryCount = Data.getU32(OffsetPtr);
50
51  // Perform basic validation of the remaining header fields.
52  if (HeaderData.Version != 5)
53    return createStringError(errc::invalid_argument,
54                       "unrecognised %s table version %" PRIu16
55                       " in table at offset 0x%" PRIx64,
56                       SectionName.data(), HeaderData.Version, HeaderOffset);
57  if (HeaderData.AddrSize != 4 && HeaderData.AddrSize != 8)
58    return createStringError(errc::not_supported,
59                       "%s table at offset 0x%" PRIx64
60                       " has unsupported address size %" PRIu8,
61                       SectionName.data(), HeaderOffset, HeaderData.AddrSize);
62  if (HeaderData.SegSize != 0)
63    return createStringError(errc::not_supported,
64                       "%s table at offset 0x%" PRIx64
65                       " has unsupported segment selector size %" PRIu8,
66                       SectionName.data(), HeaderOffset, HeaderData.SegSize);
67  if (End < HeaderOffset + getHeaderSize(Format) +
68                HeaderData.OffsetEntryCount * OffsetByteSize)
69    return createStringError(errc::invalid_argument,
70        "%s table at offset 0x%" PRIx64 " has more offset entries (%" PRIu32
71        ") than there is space for",
72        SectionName.data(), HeaderOffset, HeaderData.OffsetEntryCount);
73  Data.setAddressSize(HeaderData.AddrSize);
74  *OffsetPtr += HeaderData.OffsetEntryCount * OffsetByteSize;
75  return Error::success();
76}
77
78void DWARFListTableHeader::dump(DataExtractor Data, raw_ostream &OS,
79                                DIDumpOptions DumpOpts) const {
80  if (DumpOpts.Verbose)
81    OS << format("0x%8.8" PRIx64 ": ", HeaderOffset);
82  int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(Format);
83  OS << format("%s list header: length = 0x%0*" PRIx64, ListTypeString.data(),
84               OffsetDumpWidth, HeaderData.Length)
85     << ", format = " << dwarf::FormatString(Format)
86     << format(", version = 0x%4.4" PRIx16 ", addr_size = 0x%2.2" PRIx8
87               ", seg_size = 0x%2.2" PRIx8
88               ", offset_entry_count = 0x%8.8" PRIx32 "\n",
89               HeaderData.Version, HeaderData.AddrSize, HeaderData.SegSize,
90               HeaderData.OffsetEntryCount);
91
92  if (HeaderData.OffsetEntryCount > 0) {
93    OS << "offsets: [";
94    for (uint32_t I = 0; I < HeaderData.OffsetEntryCount; ++I) {
95      auto Off = *getOffsetEntry(Data, I);
96      OS << format("\n0x%0*" PRIx64, OffsetDumpWidth, Off);
97      if (DumpOpts.Verbose)
98        OS << format(" => 0x%08" PRIx64,
99                     Off + HeaderOffset + getHeaderSize(Format));
100    }
101    OS << "\n]\n";
102  }
103}
104
105uint64_t DWARFListTableHeader::length() const {
106  if (HeaderData.Length == 0)
107    return 0;
108  return HeaderData.Length + dwarf::getUnitLengthFieldByteSize(Format);
109}
110