1 files changed, 146 insertions, 0 deletions
diff --git a/source/Host/common/LZMA.cpp b/source/Host/common/LZMA.cpp
new file mode 100644
index 0000000000000..02be8a09df66a
--- /dev/null
+++ b/source/Host/common/LZMA.cpp
@@ -0,0 +1,146 @@
+//===-- 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