lldb/source/Host/common/LZMA.cpp

   1 //===-- LZMA.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 "lldb/Host/Config.h"
  10 #include "llvm/ADT/StringRef.h"
  11 #include "llvm/Support/Error.h"
  12
  13 #if LLDB_ENABLE_LZMA
  14 #include <lzma.h>
  15 #endif // LLDB_ENABLE_LZMA
  16
  17 namespace lldb_private {
  18
  19 namespace lzma {
  20
  21 #if !LLDB_ENABLE_LZMA
  22 bool isAvailable() { return false; }
  23 llvm::Expected<uint64_t>
  24 getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer) {
  25   llvm_unreachable("lzma::getUncompressedSize is unavailable");
  26 }
  27
  28 llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
  29                        llvm::SmallVectorImpl<uint8_t> &Uncompressed) {
  30   llvm_unreachable("lzma::uncompress is unavailable");
  31 }
  32
  33 #else // LLDB_ENABLE_LZMA
  34
  35 bool isAvailable() { return true; }
  36
  37 static const char *convertLZMACodeToString(lzma_ret Code) {
  38   switch (Code) {
  39   case LZMA_STREAM_END:
  40     return "lzma error: LZMA_STREAM_END";
  41   case LZMA_NO_CHECK:
  42     return "lzma error: LZMA_NO_CHECK";
  43   case LZMA_UNSUPPORTED_CHECK:
  44     return "lzma error: LZMA_UNSUPPORTED_CHECK";
  45   case LZMA_GET_CHECK:
  46     return "lzma error: LZMA_GET_CHECK";
  47   case LZMA_MEM_ERROR:
  48     return "lzma error: LZMA_MEM_ERROR";
  49   case LZMA_MEMLIMIT_ERROR:
  50     return "lzma error: LZMA_MEMLIMIT_ERROR";
  51   case LZMA_FORMAT_ERROR:
  52     return "lzma error: LZMA_FORMAT_ERROR";
  53   case LZMA_OPTIONS_ERROR:
  54     return "lzma error: LZMA_OPTIONS_ERROR";
  55   case LZMA_DATA_ERROR:
  56     return "lzma error: LZMA_DATA_ERROR";
  57   case LZMA_BUF_ERROR:
  58     return "lzma error: LZMA_BUF_ERROR";
  59   case LZMA_PROG_ERROR:
  60     return "lzma error: LZMA_PROG_ERROR";
  61   default:
  62     llvm_unreachable("unknown or unexpected lzma status code");
  63   }
  64 }
  65
  66 llvm::Expected<uint64_t>
  67 getUncompressedSize(llvm::ArrayRef<uint8_t> InputBuffer) {
  68   lzma_stream_flags opts{};
  69   if (InputBuffer.size() < LZMA_STREAM_HEADER_SIZE) {
  70     return llvm::createStringError(
  71         llvm::inconvertibleErrorCode(),
  72         "size of xz-compressed blob (%lu bytes) is smaller than the "
  73         "LZMA_STREAM_HEADER_SIZE (%lu bytes)",
  74         InputBuffer.size(), LZMA_STREAM_HEADER_SIZE);
  75   }
  76
  77   // Decode xz footer.
  78   lzma_ret xzerr = lzma_stream_footer_decode(
  79       &opts, InputBuffer.take_back(LZMA_STREAM_HEADER_SIZE).data());
  80   if (xzerr != LZMA_OK) {
  81     return llvm::createStringError(llvm::inconvertibleErrorCode(),
  82                                    "lzma_stream_footer_decode()=%s",
  83                                    convertLZMACodeToString(xzerr));
  84   }
  85   if (InputBuffer.size() < (opts.backward_size + LZMA_STREAM_HEADER_SIZE)) {
  86     return llvm::createStringError(
  87         llvm::inconvertibleErrorCode(),
  88         "xz-compressed buffer size (%lu bytes) too small (required at "
  89         "least %lu bytes) ",
  90         InputBuffer.size(), (opts.backward_size + LZMA_STREAM_HEADER_SIZE));
  91   }
  92
  93   // Decode xz index.
  94   lzma_index *xzindex;
  95   uint64_t memlimit(UINT64_MAX);
  96   size_t inpos = 0;
  97   xzerr = lzma_index_buffer_decode(
  98       &xzindex, &memlimit, nullptr,
  99       InputBuffer.take_back(LZMA_STREAM_HEADER_SIZE + opts.backward_size)
 100           .data(),
 101       &inpos, InputBuffer.size());
 102   if (xzerr != LZMA_OK) {
 103     return llvm::createStringError(llvm::inconvertibleErrorCode(),
 104                                    "lzma_index_buffer_decode()=%s",
 105                                    convertLZMACodeToString(xzerr));
 106   }
 107
 108   // Get size of uncompressed file to construct an in-memory buffer of the
 109   // same size on the calling end (if needed).
 110   uint64_t uncompressedSize = lzma_index_uncompressed_size(xzindex);
 111
 112   // Deallocate xz index as it is no longer needed.
 113   lzma_index_end(xzindex, nullptr);
 114
 115   return uncompressedSize;
 116 }
 117
 118 llvm::Error uncompress(llvm::ArrayRef<uint8_t> InputBuffer,
 119                        llvm::SmallVectorImpl<uint8_t> &Uncompressed) {
 120   llvm::Expected<uint64_t> uncompressedSize = getUncompressedSize(InputBuffer);
 121
 122   if (auto err = uncompressedSize.takeError())
 123     return err;
 124
 125   Uncompressed.resize(*uncompressedSize);
 126
 127   // Decompress xz buffer to buffer.
 128   uint64_t memlimit = UINT64_MAX;
 129   size_t inpos = 0;
 130   size_t outpos = 0;
 131   lzma_ret ret = lzma_stream_buffer_decode(
 132       &memlimit, 0, nullptr, InputBuffer.data(), &inpos, InputBuffer.size(),
 133       Uncompressed.data(), &outpos, Uncompressed.size());
 134   if (ret != LZMA_OK) {
 135     return llvm::createStringError(llvm::inconvertibleErrorCode(),
 136                                    "lzma_stream_buffer_decode()=%s",
 137                                    convertLZMACodeToString(ret));
 138   }
 139
 140   return llvm::Error::success();
 141 }
 142
 143 #endif // LLDB_ENABLE_LZMA
 144
 145 } // end of namespace lzma
 146 } // namespace lldb_private