llvm-project/lldb/source/Host/common/LZMA.cpp

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4.8 KiB
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//===-- LZMA.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 "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