reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    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
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
//===-- LZMA.cpp ------------------------------------------------*- C++ -*-===//
//
// 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 "lldb/Host/Config.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"

#if LLDB_ENABLE_LZMA
#include <lzma.h>
#endif // LLDB_ENABLE_LZMA

namespace lldb_private {

namespace lzma {

#if !LLDB_ENABLE_LZMA
bool isAvailable() { return false; }
llvm::Expected<uint64_t>
getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer) {
  llvm_unreachable("lzma::getUncompressedSize is unavailable");
}

llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
                       llvm::SmallVectorImpl<uint8_t> &Uncompressed) {
  llvm_unreachable("lzma::uncompress is unavailable");
}

#else // LLDB_ENABLE_LZMA

bool isAvailable() { return true; }

static const char *convertLZMACodeToString(lzma_ret Code) {
  switch (Code) {
  case LZMA_STREAM_END:
    return "lzma error: LZMA_STREAM_END";
  case LZMA_NO_CHECK:
    return "lzma error: LZMA_NO_CHECK";
  case LZMA_UNSUPPORTED_CHECK:
    return "lzma error: LZMA_UNSUPPORTED_CHECK";
  case LZMA_GET_CHECK:
    return "lzma error: LZMA_GET_CHECK";
  case LZMA_MEM_ERROR:
    return "lzma error: LZMA_MEM_ERROR";
  case LZMA_MEMLIMIT_ERROR:
    return "lzma error: LZMA_MEMLIMIT_ERROR";
  case LZMA_FORMAT_ERROR:
    return "lzma error: LZMA_FORMAT_ERROR";
  case LZMA_OPTIONS_ERROR:
    return "lzma error: LZMA_OPTIONS_ERROR";
  case LZMA_DATA_ERROR:
    return "lzma error: LZMA_DATA_ERROR";
  case LZMA_BUF_ERROR:
    return "lzma error: LZMA_BUF_ERROR";
  case LZMA_PROG_ERROR:
    return "lzma error: LZMA_PROG_ERROR";
  default:
    llvm_unreachable("unknown or unexpected lzma status code");
  }
}

llvm::Expected<uint64_t>
getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer) {
  lzma_stream_flags opts{};
  if (InputBuffer.size() < LZMA_STREAM_HEADER_SIZE) {
    return llvm::createStringError(
        llvm::inconvertibleErrorCode(),
        "size of xz-compressed blob (%lu bytes) is smaller than the "
        "LZMA_STREAM_HEADER_SIZE (%lu bytes)",
        InputBuffer.size(), LZMA_STREAM_HEADER_SIZE);
  }

  // Decode xz footer.
  lzma_ret xzerr = lzma_stream_footer_decode(
      &opts, InputBuffer.take_back(LZMA_STREAM_HEADER_SIZE).data());
  if (xzerr != LZMA_OK) {
    return llvm::createStringError(llvm::inconvertibleErrorCode(),
                                   "lzma_stream_footer_decode()=%s",
                                   convertLZMACodeToString(xzerr));
  }
  if (InputBuffer.size() < (opts.backward_size + LZMA_STREAM_HEADER_SIZE)) {
    return llvm::createStringError(
        llvm::inconvertibleErrorCode(),
        "xz-compressed buffer size (%lu bytes) too small (required at "
        "least %lu bytes) ",
        InputBuffer.size(), (opts.backward_size + LZMA_STREAM_HEADER_SIZE));
  }

  // Decode xz index.
  lzma_index *xzindex;
  uint64_t memlimit(UINT64_MAX);
  size_t inpos = 0;
  xzerr = lzma_index_buffer_decode(
      &xzindex, &memlimit, nullptr,
      InputBuffer.take_back(LZMA_STREAM_HEADER_SIZE + opts.backward_size)
          .data(),
      &inpos, InputBuffer.size());
  if (xzerr != LZMA_OK) {
    return llvm::createStringError(llvm::inconvertibleErrorCode(),
                                   "lzma_index_buffer_decode()=%s",
                                   convertLZMACodeToString(xzerr));
  }

  // Get size of uncompressed file to construct an in-memory buffer of the
  // same size on the calling end (if needed).
  uint64_t uncompressedSize = lzma_index_uncompressed_size(xzindex);

  // Deallocate xz index as it is no longer needed.
  lzma_index_end(xzindex, nullptr);

  return uncompressedSize;
}

llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
                       llvm::SmallVectorImpl<uint8_t> &Uncompressed) {
  llvm::Expected<uint64_t> uncompressedSize = getUncompressedSize(InputBuffer);

  if (auto err = uncompressedSize.takeError())
    return err;

  Uncompressed.resize(*uncompressedSize);

  // Decompress xz buffer to buffer.
  uint64_t memlimit = UINT64_MAX;
  size_t inpos = 0;
  size_t outpos = 0;
  lzma_ret ret = lzma_stream_buffer_decode(
      &memlimit, 0, nullptr, InputBuffer.data(), &inpos, InputBuffer.size(),
      Uncompressed.data(), &outpos, Uncompressed.size());
  if (ret != LZMA_OK) {
    return llvm::createStringError(llvm::inconvertibleErrorCode(),
                                   "lzma_stream_buffer_decode()=%s",
                                   convertLZMACodeToString(ret));
  }

  return llvm::Error::success();
}

#endif // LLDB_ENABLE_LZMA

} // end of namespace lzma
} // namespace lldb_private