1 files changed, 99 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Support/Compression.cpp b/contrib/llvm/lib/Support/Compression.cpp
new file mode 100644
index 000000000000..b54613e92b8b
--- /dev/null
+++ b/contrib/llvm/lib/Support/Compression.cpp
@@ -0,0 +1,99 @@
+//===--- Compression.cpp - Compression implementation ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements compression functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Compression.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Config/config.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
+#if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
+#include <zlib.h>
+#endif
+
+using namespace llvm;
+
+#if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
+static int encodeZlibCompressionLevel(zlib::CompressionLevel Level) {
+  switch (Level) {
+    case zlib::NoCompression: return 0;
+    case zlib::BestSpeedCompression: return 1;
+    case zlib::DefaultCompression: return Z_DEFAULT_COMPRESSION;
+    case zlib::BestSizeCompression: return 9;
+  }
+  llvm_unreachable("Invalid zlib::CompressionLevel!");
+}
+
+static zlib::Status encodeZlibReturnValue(int ReturnValue) {
+  switch (ReturnValue) {
+    case Z_OK: return zlib::StatusOK;
+    case Z_MEM_ERROR: return zlib::StatusOutOfMemory;
+    case Z_BUF_ERROR: return zlib::StatusBufferTooShort;
+    case Z_STREAM_ERROR: return zlib::StatusInvalidArg;
+    case Z_DATA_ERROR: return zlib::StatusInvalidData;
+    default: llvm_unreachable("unknown zlib return status!");
+  }
+}
+
+bool zlib::isAvailable() { return true; }
+zlib::Status zlib::compress(StringRef InputBuffer,
+                            SmallVectorImpl<char> &CompressedBuffer,
+                            CompressionLevel Level) {
+  unsigned long CompressedSize = ::compressBound(InputBuffer.size());
+  CompressedBuffer.resize(CompressedSize);
+  int CLevel = encodeZlibCompressionLevel(Level);
+  Status Res = encodeZlibReturnValue(::compress2(
+      (Bytef *)CompressedBuffer.data(), &CompressedSize,
+      (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel));
+  // Tell MemorySanitizer that zlib output buffer is fully initialized.
+  // This avoids a false report when running LLVM with uninstrumented ZLib.
+  __msan_unpoison(CompressedBuffer.data(), CompressedSize);
+  CompressedBuffer.resize(CompressedSize);
+  return Res;
+}
+
+zlib::Status zlib::uncompress(StringRef InputBuffer,
+                              SmallVectorImpl<char> &UncompressedBuffer,
+                              size_t UncompressedSize) {
+  UncompressedBuffer.resize(UncompressedSize);
+  Status Res = encodeZlibReturnValue(::uncompress(
+      (Bytef *)UncompressedBuffer.data(), (uLongf *)&UncompressedSize,
+      (const Bytef *)InputBuffer.data(), InputBuffer.size()));
+  // Tell MemorySanitizer that zlib output buffer is fully initialized.
+  // This avoids a false report when running LLVM with uninstrumented ZLib.
+  __msan_unpoison(UncompressedBuffer.data(), UncompressedSize);
+  UncompressedBuffer.resize(UncompressedSize);
+  return Res;
+}
+
+uint32_t zlib::crc32(StringRef Buffer) {
+  return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size());
+}
+
+#else
+bool zlib::isAvailable() { return false; }
+zlib::Status zlib::compress(StringRef InputBuffer,
+                            SmallVectorImpl<char> &CompressedBuffer,
+                            CompressionLevel Level) {
+  return zlib::StatusUnsupported;
+}
+zlib::Status zlib::uncompress(StringRef InputBuffer,
+                              SmallVectorImpl<char> &UncompressedBuffer,
+                              size_t UncompressedSize) {
+  return zlib::StatusUnsupported;
+}
+uint32_t zlib::crc32(StringRef Buffer) {
+  llvm_unreachable("zlib::crc32 is unavailable");
+}
+#endif
+