xref: /freebsd/contrib/llvm-project/llvm/lib/Support/Compression.cpp (revision 7ef62cebc2f965b0f640263e179276928885e33d)
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
221