1 //===--- Compression.cpp - Compression implementation ---------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements compression functions. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Support/Compression.h" 14 #include "llvm/ADT/SmallVector.h" 15 #include "llvm/ADT/StringRef.h" 16 #include "llvm/Config/config.h" 17 #include "llvm/Support/Compiler.h" 18 #include "llvm/Support/Error.h" 19 #include "llvm/Support/ErrorHandling.h" 20 #if LLVM_ENABLE_ZLIB 21 #include <zlib.h> 22 #endif 23 24 using namespace llvm; 25 26 #if LLVM_ENABLE_ZLIB 27 static Error createError(StringRef Err) { 28 return make_error<StringError>(Err, inconvertibleErrorCode()); 29 } 30 31 static StringRef convertZlibCodeToString(int Code) { 32 switch (Code) { 33 case Z_MEM_ERROR: 34 return "zlib error: Z_MEM_ERROR"; 35 case Z_BUF_ERROR: 36 return "zlib error: Z_BUF_ERROR"; 37 case Z_STREAM_ERROR: 38 return "zlib error: Z_STREAM_ERROR"; 39 case Z_DATA_ERROR: 40 return "zlib error: Z_DATA_ERROR"; 41 case Z_OK: 42 default: 43 llvm_unreachable("unknown or unexpected zlib status code"); 44 } 45 } 46 47 bool zlib::isAvailable() { return true; } 48 49 Error zlib::compress(StringRef InputBuffer, 50 SmallVectorImpl<char> &CompressedBuffer, int Level) { 51 unsigned long CompressedSize = ::compressBound(InputBuffer.size()); 52 CompressedBuffer.reserve(CompressedSize); 53 int Res = 54 ::compress2((Bytef *)CompressedBuffer.data(), &CompressedSize, 55 (const Bytef *)InputBuffer.data(), InputBuffer.size(), Level); 56 // Tell MemorySanitizer that zlib output buffer is fully initialized. 57 // This avoids a false report when running LLVM with uninstrumented ZLib. 58 __msan_unpoison(CompressedBuffer.data(), CompressedSize); 59 CompressedBuffer.set_size(CompressedSize); 60 return Res ? createError(convertZlibCodeToString(Res)) : Error::success(); 61 } 62 63 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer, 64 size_t &UncompressedSize) { 65 int Res = 66 ::uncompress((Bytef *)UncompressedBuffer, (uLongf *)&UncompressedSize, 67 (const Bytef *)InputBuffer.data(), InputBuffer.size()); 68 // Tell MemorySanitizer that zlib output buffer is fully initialized. 69 // This avoids a false report when running LLVM with uninstrumented ZLib. 70 __msan_unpoison(UncompressedBuffer, UncompressedSize); 71 return Res ? createError(convertZlibCodeToString(Res)) : Error::success(); 72 } 73 74 Error zlib::uncompress(StringRef InputBuffer, 75 SmallVectorImpl<char> &UncompressedBuffer, 76 size_t UncompressedSize) { 77 UncompressedBuffer.reserve(UncompressedSize); 78 Error E = 79 uncompress(InputBuffer, UncompressedBuffer.data(), UncompressedSize); 80 UncompressedBuffer.set_size(UncompressedSize); 81 return E; 82 } 83 84 uint32_t zlib::crc32(StringRef Buffer) { 85 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size()); 86 } 87 88 #else 89 bool zlib::isAvailable() { return false; } 90 Error zlib::compress(StringRef InputBuffer, 91 SmallVectorImpl<char> &CompressedBuffer, int Level) { 92 llvm_unreachable("zlib::compress is unavailable"); 93 } 94 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer, 95 size_t &UncompressedSize) { 96 llvm_unreachable("zlib::uncompress is unavailable"); 97 } 98 Error zlib::uncompress(StringRef InputBuffer, 99 SmallVectorImpl<char> &UncompressedBuffer, 100 size_t UncompressedSize) { 101 llvm_unreachable("zlib::uncompress is unavailable"); 102 } 103 uint32_t zlib::crc32(StringRef Buffer) { 104 llvm_unreachable("zlib::crc32 is unavailable"); 105 } 106 #endif 107