1 //===--- Compression.cpp - Compression implementation ---------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements compression functions. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Support/Compression.h" 15 #include "llvm/ADT/SmallVector.h" 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/Config/config.h" 18 #include "llvm/Support/Compiler.h" 19 #include "llvm/Support/Error.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H 22 #include <zlib.h> 23 #endif 24 25 using namespace llvm; 26 27 #if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ 28 static Error createError(StringRef Err) { 29 return make_error<StringError>(Err, inconvertibleErrorCode()); 30 } 31 32 static StringRef convertZlibCodeToString(int Code) { 33 switch (Code) { 34 case Z_MEM_ERROR: 35 return "zlib error: Z_MEM_ERROR"; 36 case Z_BUF_ERROR: 37 return "zlib error: Z_BUF_ERROR"; 38 case Z_STREAM_ERROR: 39 return "zlib error: Z_STREAM_ERROR"; 40 case Z_DATA_ERROR: 41 return "zlib error: Z_DATA_ERROR"; 42 case Z_OK: 43 default: 44 llvm_unreachable("unknown or unexpected zlib status code"); 45 } 46 } 47 48 bool zlib::isAvailable() { return true; } 49 50 Error zlib::compress(StringRef InputBuffer, 51 SmallVectorImpl<char> &CompressedBuffer, int Level) { 52 unsigned long CompressedSize = ::compressBound(InputBuffer.size()); 53 CompressedBuffer.reserve(CompressedSize); 54 int Res = 55 ::compress2((Bytef *)CompressedBuffer.data(), &CompressedSize, 56 (const Bytef *)InputBuffer.data(), InputBuffer.size(), Level); 57 // Tell MemorySanitizer that zlib output buffer is fully initialized. 58 // This avoids a false report when running LLVM with uninstrumented ZLib. 59 __msan_unpoison(CompressedBuffer.data(), CompressedSize); 60 CompressedBuffer.set_size(CompressedSize); 61 return Res ? createError(convertZlibCodeToString(Res)) : Error::success(); 62 } 63 64 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer, 65 size_t &UncompressedSize) { 66 int Res = 67 ::uncompress((Bytef *)UncompressedBuffer, (uLongf *)&UncompressedSize, 68 (const Bytef *)InputBuffer.data(), InputBuffer.size()); 69 // Tell MemorySanitizer that zlib output buffer is fully initialized. 70 // This avoids a false report when running LLVM with uninstrumented ZLib. 71 __msan_unpoison(UncompressedBuffer, UncompressedSize); 72 return Res ? createError(convertZlibCodeToString(Res)) : Error::success(); 73 } 74 75 Error zlib::uncompress(StringRef InputBuffer, 76 SmallVectorImpl<char> &UncompressedBuffer, 77 size_t UncompressedSize) { 78 UncompressedBuffer.resize(UncompressedSize); 79 Error E = 80 uncompress(InputBuffer, UncompressedBuffer.data(), UncompressedSize); 81 UncompressedBuffer.resize(UncompressedSize); 82 return E; 83 } 84 85 uint32_t zlib::crc32(StringRef Buffer) { 86 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size()); 87 } 88 89 #else 90 bool zlib::isAvailable() { return false; } 91 Error zlib::compress(StringRef InputBuffer, 92 SmallVectorImpl<char> &CompressedBuffer, 93 CompressionLevel Level) { 94 llvm_unreachable("zlib::compress is unavailable"); 95 } 96 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer, 97 size_t &UncompressedSize) { 98 llvm_unreachable("zlib::uncompress is unavailable"); 99 } 100 Error zlib::uncompress(StringRef InputBuffer, 101 SmallVectorImpl<char> &UncompressedBuffer, 102 size_t UncompressedSize) { 103 llvm_unreachable("zlib::uncompress is unavailable"); 104 } 105 uint32_t zlib::crc32(StringRef Buffer) { 106 llvm_unreachable("zlib::crc32 is unavailable"); 107 } 108 #endif 109