llvm/lib/Support/Compression.cpp

   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 #if LLVM_ENABLE_ZSTD
  24 #include <zstd.h>
  25 #endif
  26
  27 using namespace llvm;
  28 using namespace llvm::compression;
  29
  30 const char *compression::getReasonIfUnsupported(compression::Format F) {
  31   switch (F) {
  32   case compression::Format::Zlib:
  33     if (zlib::isAvailable())
  34       return nullptr;
  35     return "LLVM was not built with LLVM_ENABLE_ZLIB or did not find zlib at "
  36            "build time";
  37   case compression::Format::Zstd:
  38     if (zstd::isAvailable())
  39       return nullptr;
  40     return "LLVM was not built with LLVM_ENABLE_ZSTD or did not find zstd at "
  41            "build time";
  42   }
  43   llvm_unreachable("");
  44 }
  45
  46 void compression::compress(Params P, ArrayRef<uint8_t> Input,
  47                            SmallVectorImpl<uint8_t> &Output) {
  48   switch (P.format) {
  49   case compression::Format::Zlib:
  50     zlib::compress(Input, Output, P.level);
  51     break;
  52   case compression::Format::Zstd:
  53     zstd::compress(Input, Output, P.level);
  54     break;
  55   }
  56 }
  57
  58 Error compression::decompress(DebugCompressionType T, ArrayRef<uint8_t> Input,
  59                               uint8_t *Output, size_t UncompressedSize) {
  60   switch (formatFor(T)) {
  61   case compression::Format::Zlib:
  62     return zlib::decompress(Input, Output, UncompressedSize);
  63   case compression::Format::Zstd:
  64     return zstd::decompress(Input, Output, UncompressedSize);
  65   }
  66   llvm_unreachable("");
  67 }
  68
  69 Error compression::decompress(compression::Format F, ArrayRef<uint8_t> Input,
  70                               SmallVectorImpl<uint8_t> &Output,
  71                               size_t UncompressedSize) {
  72   switch (F) {
  73   case compression::Format::Zlib:
  74     return zlib::decompress(Input, Output, UncompressedSize);
  75   case compression::Format::Zstd:
  76     return zstd::decompress(Input, Output, UncompressedSize);
  77   }
  78   llvm_unreachable("");
  79 }
  80
  81 Error compression::decompress(DebugCompressionType T, ArrayRef<uint8_t> Input,
  82                               SmallVectorImpl<uint8_t> &Output,
  83                               size_t UncompressedSize) {
  84   return decompress(formatFor(T), Input, Output, UncompressedSize);
  85 }
  86
  87 #if LLVM_ENABLE_ZLIB
  88
  89 static StringRef convertZlibCodeToString(int Code) {
  90   switch (Code) {
  91   case Z_MEM_ERROR:
  92     return "zlib error: Z_MEM_ERROR";
  93   case Z_BUF_ERROR:
  94     return "zlib error: Z_BUF_ERROR";
  95   case Z_STREAM_ERROR:
  96     return "zlib error: Z_STREAM_ERROR";
  97   case Z_DATA_ERROR:
  98     return "zlib error: Z_DATA_ERROR";
  99   case Z_OK:
 100   default:
 101     llvm_unreachable("unknown or unexpected zlib status code");
 102   }
 103 }
 104
 105 bool zlib::isAvailable() { return true; }
 106
 107 void zlib::compress(ArrayRef<uint8_t> Input,
 108                     SmallVectorImpl<uint8_t> &CompressedBuffer, int Level) {
 109   unsigned long CompressedSize = ::compressBound(Input.size());
 110   CompressedBuffer.resize_for_overwrite(CompressedSize);
 111   int Res = ::compress2((Bytef *)CompressedBuffer.data(), &CompressedSize,
 112                         (const Bytef *)Input.data(), Input.size(), Level);
 113   if (Res == Z_MEM_ERROR)
 114     report_bad_alloc_error("Allocation failed");
 115   assert(Res == Z_OK);
 116   // Tell MemorySanitizer that zlib output buffer is fully initialized.
 117   // This avoids a false report when running LLVM with uninstrumented ZLib.
 118   __msan_unpoison(CompressedBuffer.data(), CompressedSize);
 119   if (CompressedSize < CompressedBuffer.size())
 120     CompressedBuffer.truncate(CompressedSize);
 121 }
 122
 123 Error zlib::decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
 124                        size_t &UncompressedSize) {
 125   int Res = ::uncompress((Bytef *)Output, (uLongf *)&UncompressedSize,
 126                          (const Bytef *)Input.data(), Input.size());
 127   // Tell MemorySanitizer that zlib output buffer is fully initialized.
 128   // This avoids a false report when running LLVM with uninstrumented ZLib.
 129   __msan_unpoison(Output, UncompressedSize);
 130   return Res ? make_error<StringError>(convertZlibCodeToString(Res),
 131                                        inconvertibleErrorCode())
 132              : Error::success();
 133 }
 134
 135 Error zlib::decompress(ArrayRef<uint8_t> Input,
 136                        SmallVectorImpl<uint8_t> &Output,
 137                        size_t UncompressedSize) {
 138   Output.resize_for_overwrite(UncompressedSize);
 139   Error E = zlib::decompress(Input, Output.data(), UncompressedSize);
 140   if (UncompressedSize < Output.size())
 141     Output.truncate(UncompressedSize);
 142   return E;
 143 }
 144
 145 #else
 146 bool zlib::isAvailable() { return false; }
 147 void zlib::compress(ArrayRef<uint8_t> Input,
 148                     SmallVectorImpl<uint8_t> &CompressedBuffer, int Level) {
 149   llvm_unreachable("zlib::compress is unavailable");
 150 }
 151 Error zlib::decompress(ArrayRef<uint8_t> Input, uint8_t *UncompressedBuffer,
 152                        size_t &UncompressedSize) {
 153   llvm_unreachable("zlib::decompress is unavailable");
 154 }
 155 Error zlib::decompress(ArrayRef<uint8_t> Input,
 156                        SmallVectorImpl<uint8_t> &UncompressedBuffer,
 157                        size_t UncompressedSize) {
 158   llvm_unreachable("zlib::decompress is unavailable");
 159 }
 160 #endif
 161
 162 #if LLVM_ENABLE_ZSTD
 163
 164 bool zstd::isAvailable() { return true; }
 165
 166 void zstd::compress(ArrayRef<uint8_t> Input,
 167                     SmallVectorImpl<uint8_t> &CompressedBuffer, int Level) {
 168   unsigned long CompressedBufferSize = ::ZSTD_compressBound(Input.size());
 169   CompressedBuffer.resize_for_overwrite(CompressedBufferSize);
 170   unsigned long CompressedSize =
 171       ::ZSTD_compress((char *)CompressedBuffer.data(), CompressedBufferSize,
 172                       (const char *)Input.data(), Input.size(), Level);
 173   if (ZSTD_isError(CompressedSize))
 174     report_bad_alloc_error("Allocation failed");
 175   // Tell MemorySanitizer that zstd output buffer is fully initialized.
 176   // This avoids a false report when running LLVM with uninstrumented ZLib.
 177   __msan_unpoison(CompressedBuffer.data(), CompressedSize);
 178   if (CompressedSize < CompressedBuffer.size())
 179     CompressedBuffer.truncate(CompressedSize);
 180 }
 181
 182 Error zstd::decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
 183                        size_t &UncompressedSize) {
 184   const size_t Res = ::ZSTD_decompress(
 185       Output, UncompressedSize, (const uint8_t *)Input.data(), Input.size());
 186   UncompressedSize = Res;
 187   // Tell MemorySanitizer that zstd output buffer is fully initialized.
 188   // This avoids a false report when running LLVM with uninstrumented ZLib.
 189   __msan_unpoison(Output, UncompressedSize);
 190   return ZSTD_isError(Res) ? make_error<StringError>(ZSTD_getErrorName(Res),
 191                                                      inconvertibleErrorCode())
 192                            : Error::success();
 193 }
 194
 195 Error zstd::decompress(ArrayRef<uint8_t> Input,
 196                        SmallVectorImpl<uint8_t> &Output,
 197                        size_t UncompressedSize) {
 198   Output.resize_for_overwrite(UncompressedSize);
 199   Error E = zstd::decompress(Input, Output.data(), UncompressedSize);
 200   if (UncompressedSize < Output.size())
 201     Output.truncate(UncompressedSize);
 202   return E;
 203 }
 204
 205 #else
 206 bool zstd::isAvailable() { return false; }
 207 void zstd::compress(ArrayRef<uint8_t> Input,
 208                     SmallVectorImpl<uint8_t> &CompressedBuffer, int Level) {
 209   llvm_unreachable("zstd::compress is unavailable");
 210 }
 211 Error zstd::decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
 212                        size_t &UncompressedSize) {
 213   llvm_unreachable("zstd::decompress is unavailable");
 214 }
 215 Error zstd::decompress(ArrayRef<uint8_t> Input,
 216                        SmallVectorImpl<uint8_t> &Output,
 217                        size_t UncompressedSize) {
 218   llvm_unreachable("zstd::decompress is unavailable");
 219 }
 220 #endif