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
createError(StringRef Err)28 static Error createError(StringRef Err) {
29 return make_error<StringError>(Err, inconvertibleErrorCode());
30 }
31
convertZlibCodeToString(int Code)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
isAvailable()48 bool zlib::isAvailable() { return true; }
49
compress(StringRef InputBuffer,SmallVectorImpl<char> & CompressedBuffer,int Level)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
uncompress(StringRef InputBuffer,char * UncompressedBuffer,size_t & UncompressedSize)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
uncompress(StringRef InputBuffer,SmallVectorImpl<char> & UncompressedBuffer,size_t UncompressedSize)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
crc32(StringRef Buffer)85 uint32_t zlib::crc32(StringRef Buffer) {
86 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size());
87 }
88
89 #else
isAvailable()90 bool zlib::isAvailable() { return false; }
compress(StringRef InputBuffer,SmallVectorImpl<char> & CompressedBuffer,int Level)91 Error zlib::compress(StringRef InputBuffer,
92 SmallVectorImpl<char> &CompressedBuffer, int Level) {
93 llvm_unreachable("zlib::compress is unavailable");
94 }
uncompress(StringRef InputBuffer,char * UncompressedBuffer,size_t & UncompressedSize)95 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
96 size_t &UncompressedSize) {
97 llvm_unreachable("zlib::uncompress is unavailable");
98 }
uncompress(StringRef InputBuffer,SmallVectorImpl<char> & UncompressedBuffer,size_t UncompressedSize)99 Error zlib::uncompress(StringRef InputBuffer,
100 SmallVectorImpl<char> &UncompressedBuffer,
101 size_t UncompressedSize) {
102 llvm_unreachable("zlib::uncompress is unavailable");
103 }
crc32(StringRef Buffer)104 uint32_t zlib::crc32(StringRef Buffer) {
105 llvm_unreachable("zlib::crc32 is unavailable");
106 }
107 #endif
108