aboutsummaryrefslogtreecommitdiff
path: root/src/common/dwarf/bytereader.cc
blob: ca072980e49f75a9098842d5ffda802a8b6517ca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
// Copyright (c) 2010 Google Inc. All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include <assert.h>

#include "common/dwarf/bytereader-inl.h"
#include "common/dwarf/bytereader.h"

namespace dwarf2reader {

ByteReader::ByteReader(enum Endianness endian)
    :offset_reader_(NULL), address_reader_(NULL), endian_(endian),
     address_size_(0), offset_size_(0)
{ }

ByteReader::~ByteReader() { }

void ByteReader::SetOffsetSize(uint8 size) {
  offset_size_ = size;
  assert(size == 4 || size == 8);
  if (size == 4) {
    this->offset_reader_ = &ByteReader::ReadFourBytes;
  } else {
    this->offset_reader_ = &ByteReader::ReadEightBytes;
  }
}

void ByteReader::SetAddressSize(uint8 size) {
  address_size_ = size;
  assert(size == 4 || size == 8);
  if (size == 4) {
    this->address_reader_ = &ByteReader::ReadFourBytes;
  } else {
    this->address_reader_ = &ByteReader::ReadEightBytes;
  }
}

uint64 ByteReader::ReadInitialLength(const char* start, size_t* len) {
  const uint64 initial_length = ReadFourBytes(start);
  start += 4;

  // In DWARF2/3, if the initial length is all 1 bits, then the offset
  // size is 8 and we need to read the next 8 bytes for the real length.
  if (initial_length == 0xffffffff) {
    SetOffsetSize(8);
    *len = 12;
    return ReadOffset(start);
  } else {
    SetOffsetSize(4);
    *len = 4;
  }
  return initial_length;
}

}  // namespace dwarf2reader