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

include/llvm/Support/Compression.h

@@ -0,0 +1,58 @@
+//===-- llvm/Support/Compression.h ---Compression----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains basic functions for compression/uncompression.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_COMPRESSION_H
+#define LLVM_SUPPORT_COMPRESSION_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+class MemoryBuffer;
+template<typename T> class OwningPtr;
+class StringRef;
+
+namespace zlib {
+
+enum CompressionLevel {
+  NoCompression,
+  DefaultCompression,
+  BestSpeedCompression,
+  BestSizeCompression
+};
+
+enum Status {
+  StatusOK,
+  StatusUnsupported,  // zlib is unavaliable
+  StatusOutOfMemory,  // there was not enough memory
+  StatusBufferTooShort,  // there was not enough room in the output buffer
+  StatusInvalidArg,  // invalid input parameter
+  StatusInvalidData  // data was corrupted or incomplete
+};
+
+bool isAvailable();
+
+Status compress(StringRef InputBuffer,
+                OwningPtr<MemoryBuffer> &CompressedBuffer,
+                CompressionLevel Level = DefaultCompression);
+
+Status uncompress(StringRef InputBuffer,
+                  OwningPtr<MemoryBuffer> &UncompressedBuffer,
+                  size_t UncompressedSize);
+
+}  // End of namespace zlib
+
+} // End of namespace llvm
+
+#endif
+