Add basic zlib support to LLVM. This would allow to use compression/uncompression in selected LLVM tools.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180083 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Compression.cpp b/lib/Support/Compression.cpp
new file mode 100644
index 0000000..d0adf79
--- /dev/null
+++ b/lib/Support/Compression.cpp
@@ -0,0 +1,89 @@
+//===--- 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/OwningPtr.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Config/config.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/MemoryBuffer.h"
+#if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
+#include <zlib.h>
+#endif
+
+using namespace llvm;
+
+#if LLVM_ENABLE_ZLIB == 1
+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;
+ }
+}
+
+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,
+ OwningPtr<MemoryBuffer> &CompressedBuffer,
+ CompressionLevel Level) {
+ unsigned long CompressedSize = ::compressBound(InputBuffer.size());
+ OwningArrayPtr<char> TmpBuffer(new char[CompressedSize]);
+ int CLevel = encodeZlibCompressionLevel(Level);
+ Status Res = encodeZlibReturnValue(::compress2(
+ (Bytef *)TmpBuffer.get(), &CompressedSize,
+ (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel));
+ if (Res == StatusOK)
+ CompressedBuffer.reset(MemoryBuffer::getMemBufferCopy(
+ StringRef(TmpBuffer.get(), CompressedSize)));
+ return Res;
+}
+
+zlib::Status zlib::uncompress(StringRef InputBuffer,
+ OwningPtr<MemoryBuffer> &UncompressedBuffer,
+ size_t UncompressedSize) {
+ OwningArrayPtr<char> TmpBuffer(new char[UncompressedSize]);
+ Status Res = encodeZlibReturnValue(
+ ::uncompress((Bytef *)TmpBuffer.get(), (uLongf *)&UncompressedSize,
+ (const Bytef *)InputBuffer.data(), InputBuffer.size()));
+ if (Res == StatusOK)
+ UncompressedBuffer.reset(MemoryBuffer::getMemBufferCopy(
+ StringRef(TmpBuffer.get(), UncompressedSize)));
+ return Res;
+}
+
+#else
+bool zlib::isAvailable() { return false; }
+zlib::Status zlib::compress(StringRef InputBuffer,
+ OwningPtr<MemoryBuffer> &CompressedBuffer,
+ CompressionLevel Level) {
+ return zlib::StatusUnsupported;
+}
+zlib::Status zlib::uncompress(StringRef InputBuffer,
+ OwningPtr<MemoryBuffer> &UncompressedBuffer,
+ size_t UncompressedSize) {
+ return zlib::StatusUnsupported;
+}
+#endif
+