Bug Summary

File:lib/Fuzzer/FuzzerMutate.cpp
Warning:line 213, column 5
Value stored to 'HandleFirst' is never read

Annotated Source Code

1//===- FuzzerMutate.cpp - Mutate a test input -----------------------------===//
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// Mutate a test input.
10//===----------------------------------------------------------------------===//
11
12#include "FuzzerCorpus.h"
13#include "FuzzerDefs.h"
14#include "FuzzerExtFunctions.h"
15#include "FuzzerIO.h"
16#include "FuzzerMutate.h"
17#include "FuzzerOptions.h"
18
19namespace fuzzer {
20
21const size_t Dictionary::kMaxDictSize;
22
23static void PrintASCII(const Word &W, const char *PrintAfter) {
24 PrintASCII(W.data(), W.size(), PrintAfter);
25}
26
27MutationDispatcher::MutationDispatcher(Random &Rand,
28 const FuzzingOptions &Options)
29 : Rand(Rand), Options(Options) {
30 DefaultMutators.insert(
31 DefaultMutators.begin(),
32 {
33 {&MutationDispatcher::Mutate_EraseBytes, "EraseBytes"},
34 {&MutationDispatcher::Mutate_InsertByte, "InsertByte"},
35 {&MutationDispatcher::Mutate_InsertRepeatedBytes,
36 "InsertRepeatedBytes"},
37 {&MutationDispatcher::Mutate_ChangeByte, "ChangeByte"},
38 {&MutationDispatcher::Mutate_ChangeBit, "ChangeBit"},
39 {&MutationDispatcher::Mutate_ShuffleBytes, "ShuffleBytes"},
40 {&MutationDispatcher::Mutate_ChangeASCIIInteger, "ChangeASCIIInt"},
41 {&MutationDispatcher::Mutate_ChangeBinaryInteger, "ChangeBinInt"},
42 {&MutationDispatcher::Mutate_CopyPart, "CopyPart"},
43 {&MutationDispatcher::Mutate_CrossOver, "CrossOver"},
44 {&MutationDispatcher::Mutate_AddWordFromManualDictionary,
45 "ManualDict"},
46 {&MutationDispatcher::Mutate_AddWordFromTemporaryAutoDictionary,
47 "TempAutoDict"},
48 {&MutationDispatcher::Mutate_AddWordFromPersistentAutoDictionary,
49 "PersAutoDict"},
50 });
51 if(Options.UseCmp)
52 DefaultMutators.push_back(
53 {&MutationDispatcher::Mutate_AddWordFromTORC, "CMP"});
54
55 if (EF->LLVMFuzzerCustomMutator)
56 Mutators.push_back({&MutationDispatcher::Mutate_Custom, "Custom"});
57 else
58 Mutators = DefaultMutators;
59
60 if (EF->LLVMFuzzerCustomCrossOver)
61 Mutators.push_back(
62 {&MutationDispatcher::Mutate_CustomCrossOver, "CustomCrossOver"});
63}
64
65static char RandCh(Random &Rand) {
66 if (Rand.RandBool()) return Rand(256);
67 const char *Special = "!*'();:@&=+$,/?%#[]012Az-`~.\xff\x00";
68 return Special[Rand(sizeof(Special) - 1)];
69}
70
71size_t MutationDispatcher::Mutate_Custom(uint8_t *Data, size_t Size,
72 size_t MaxSize) {
73 return EF->LLVMFuzzerCustomMutator(Data, Size, MaxSize, Rand.Rand());
74}
75
76size_t MutationDispatcher::Mutate_CustomCrossOver(uint8_t *Data, size_t Size,
77 size_t MaxSize) {
78 if (!Corpus || Corpus->size() < 2 || Size == 0)
79 return 0;
80 size_t Idx = Rand(Corpus->size());
81 const Unit &Other = (*Corpus)[Idx];
82 if (Other.empty())
83 return 0;
84 CustomCrossOverInPlaceHere.resize(MaxSize);
85 auto &U = CustomCrossOverInPlaceHere;
86 size_t NewSize = EF->LLVMFuzzerCustomCrossOver(
87 Data, Size, Other.data(), Other.size(), U.data(), U.size(), Rand.Rand());
88 if (!NewSize)
89 return 0;
90 assert(NewSize <= MaxSize && "CustomCrossOver returned overisized unit")((NewSize <= MaxSize && "CustomCrossOver returned overisized unit"
) ? static_cast<void> (0) : __assert_fail ("NewSize <= MaxSize && \"CustomCrossOver returned overisized unit\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 90, __PRETTY_FUNCTION__))
;
91 memcpy(Data, U.data(), NewSize);
92 return NewSize;
93}
94
95size_t MutationDispatcher::Mutate_ShuffleBytes(uint8_t *Data, size_t Size,
96 size_t MaxSize) {
97 if (Size > MaxSize || Size == 0) return 0;
98 size_t ShuffleAmount =
99 Rand(std::min(Size, (size_t)8)) + 1; // [1,8] and <= Size.
100 size_t ShuffleStart = Rand(Size - ShuffleAmount);
101 assert(ShuffleStart + ShuffleAmount <= Size)((ShuffleStart + ShuffleAmount <= Size) ? static_cast<void
> (0) : __assert_fail ("ShuffleStart + ShuffleAmount <= Size"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 101, __PRETTY_FUNCTION__))
;
102 std::shuffle(Data + ShuffleStart, Data + ShuffleStart + ShuffleAmount, Rand);
103 return Size;
104}
105
106size_t MutationDispatcher::Mutate_EraseBytes(uint8_t *Data, size_t Size,
107 size_t MaxSize) {
108 if (Size <= 1) return 0;
109 size_t N = Rand(Size / 2) + 1;
110 assert(N < Size)((N < Size) ? static_cast<void> (0) : __assert_fail (
"N < Size", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 110, __PRETTY_FUNCTION__))
;
111 size_t Idx = Rand(Size - N + 1);
112 // Erase Data[Idx:Idx+N].
113 memmove(Data + Idx, Data + Idx + N, Size - Idx - N);
114 // Printf("Erase: %zd %zd => %zd; Idx %zd\n", N, Size, Size - N, Idx);
115 return Size - N;
116}
117
118size_t MutationDispatcher::Mutate_InsertByte(uint8_t *Data, size_t Size,
119 size_t MaxSize) {
120 if (Size >= MaxSize) return 0;
121 size_t Idx = Rand(Size + 1);
122 // Insert new value at Data[Idx].
123 memmove(Data + Idx + 1, Data + Idx, Size - Idx);
124 Data[Idx] = RandCh(Rand);
125 return Size + 1;
126}
127
128size_t MutationDispatcher::Mutate_InsertRepeatedBytes(uint8_t *Data,
129 size_t Size,
130 size_t MaxSize) {
131 const size_t kMinBytesToInsert = 3;
132 if (Size + kMinBytesToInsert >= MaxSize) return 0;
133 size_t MaxBytesToInsert = std::min(MaxSize - Size, (size_t)128);
134 size_t N = Rand(MaxBytesToInsert - kMinBytesToInsert + 1) + kMinBytesToInsert;
135 assert(Size + N <= MaxSize && N)((Size + N <= MaxSize && N) ? static_cast<void>
(0) : __assert_fail ("Size + N <= MaxSize && N", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 135, __PRETTY_FUNCTION__))
;
136 size_t Idx = Rand(Size + 1);
137 // Insert new values at Data[Idx].
138 memmove(Data + Idx + N, Data + Idx, Size - Idx);
139 // Give preference to 0x00 and 0xff.
140 uint8_t Byte = Rand.RandBool() ? Rand(256) : (Rand.RandBool() ? 0 : 255);
141 for (size_t i = 0; i < N; i++)
142 Data[Idx + i] = Byte;
143 return Size + N;
144}
145
146size_t MutationDispatcher::Mutate_ChangeByte(uint8_t *Data, size_t Size,
147 size_t MaxSize) {
148 if (Size > MaxSize) return 0;
149 size_t Idx = Rand(Size);
150 Data[Idx] = RandCh(Rand);
151 return Size;
152}
153
154size_t MutationDispatcher::Mutate_ChangeBit(uint8_t *Data, size_t Size,
155 size_t MaxSize) {
156 if (Size > MaxSize) return 0;
157 size_t Idx = Rand(Size);
158 Data[Idx] ^= 1 << Rand(8);
159 return Size;
160}
161
162size_t MutationDispatcher::Mutate_AddWordFromManualDictionary(uint8_t *Data,
163 size_t Size,
164 size_t MaxSize) {
165 return AddWordFromDictionary(ManualDictionary, Data, Size, MaxSize);
166}
167
168size_t MutationDispatcher::Mutate_AddWordFromTemporaryAutoDictionary(
169 uint8_t *Data, size_t Size, size_t MaxSize) {
170 return AddWordFromDictionary(TempAutoDictionary, Data, Size, MaxSize);
171}
172
173size_t MutationDispatcher::ApplyDictionaryEntry(uint8_t *Data, size_t Size,
174 size_t MaxSize,
175 DictionaryEntry &DE) {
176 const Word &W = DE.GetW();
177 bool UsePositionHint = DE.HasPositionHint() &&
178 DE.GetPositionHint() + W.size() < Size &&
179 Rand.RandBool();
180 if (Rand.RandBool()) { // Insert W.
181 if (Size + W.size() > MaxSize) return 0;
182 size_t Idx = UsePositionHint ? DE.GetPositionHint() : Rand(Size + 1);
183 memmove(Data + Idx + W.size(), Data + Idx, Size - Idx);
184 memcpy(Data + Idx, W.data(), W.size());
185 Size += W.size();
186 } else { // Overwrite some bytes with W.
187 if (W.size() > Size) return 0;
188 size_t Idx = UsePositionHint ? DE.GetPositionHint() : Rand(Size - W.size());
189 memcpy(Data + Idx, W.data(), W.size());
190 }
191 return Size;
192}
193
194// Somewhere in the past we have observed a comparison instructions
195// with arguments Arg1 Arg2. This function tries to guess a dictionary
196// entry that will satisfy that comparison.
197// It first tries to find one of the arguments (possibly swapped) in the
198// input and if it succeeds it creates a DE with a position hint.
199// Otherwise it creates a DE with one of the arguments w/o a position hint.
200DictionaryEntry MutationDispatcher::MakeDictionaryEntryFromCMP(
201 const void *Arg1, const void *Arg2,
202 const void *Arg1Mutation, const void *Arg2Mutation,
203 size_t ArgSize, const uint8_t *Data,
204 size_t Size) {
205 ScopedDoingMyOwnMemOrStr scoped_doing_my_own_mem_os_str;
206 bool HandleFirst = Rand.RandBool();
207 const void *ExistingBytes, *DesiredBytes;
208 Word W;
209 const uint8_t *End = Data + Size;
210 for (int Arg = 0; Arg < 2; Arg++) {
211 ExistingBytes = HandleFirst ? Arg1 : Arg2;
212 DesiredBytes = HandleFirst ? Arg2Mutation : Arg1Mutation;
213 HandleFirst = !HandleFirst;
Value stored to 'HandleFirst' is never read
214 W.Set(reinterpret_cast<const uint8_t*>(DesiredBytes), ArgSize);
215 const size_t kMaxNumPositions = 8;
216 size_t Positions[kMaxNumPositions];
217 size_t NumPositions = 0;
218 for (const uint8_t *Cur = Data;
219 Cur < End && NumPositions < kMaxNumPositions; Cur++) {
220 Cur =
221 (const uint8_t *)SearchMemory(Cur, End - Cur, ExistingBytes, ArgSize);
222 if (!Cur) break;
223 Positions[NumPositions++] = Cur - Data;
224 }
225 if (!NumPositions) break;
226 return DictionaryEntry(W, Positions[Rand(NumPositions)]);
227 }
228 DictionaryEntry DE(W);
229 return DE;
230}
231
232
233template <class T>
234DictionaryEntry MutationDispatcher::MakeDictionaryEntryFromCMP(
235 T Arg1, T Arg2, const uint8_t *Data, size_t Size) {
236 if (Rand.RandBool()) Arg1 = Bswap(Arg1);
237 if (Rand.RandBool()) Arg2 = Bswap(Arg2);
238 T Arg1Mutation = Arg1 + Rand(-1, 1);
239 T Arg2Mutation = Arg2 + Rand(-1, 1);
240 return MakeDictionaryEntryFromCMP(&Arg1, &Arg2, &Arg1Mutation, &Arg2Mutation,
241 sizeof(Arg1), Data, Size);
242}
243
244DictionaryEntry MutationDispatcher::MakeDictionaryEntryFromCMP(
245 const Word &Arg1, const Word &Arg2, const uint8_t *Data, size_t Size) {
246 return MakeDictionaryEntryFromCMP(Arg1.data(), Arg2.data(), Arg1.data(),
247 Arg2.data(), Arg1.size(), Data, Size);
248}
249
250size_t MutationDispatcher::Mutate_AddWordFromTORC(
251 uint8_t *Data, size_t Size, size_t MaxSize) {
252 Word W;
253 DictionaryEntry DE;
254 switch (Rand(3)) {
255 case 0: {
256 auto X = TPC.TORC8.Get(Rand.Rand());
257 DE = MakeDictionaryEntryFromCMP(X.A, X.B, Data, Size);
258 } break;
259 case 1: {
260 auto X = TPC.TORC4.Get(Rand.Rand());
261 if ((X.A >> 16) == 0 && (X.B >> 16) == 0 && Rand.RandBool())
262 DE = MakeDictionaryEntryFromCMP((uint16_t)X.A, (uint16_t)X.B, Data, Size);
263 else
264 DE = MakeDictionaryEntryFromCMP(X.A, X.B, Data, Size);
265 } break;
266 case 2: {
267 auto X = TPC.TORCW.Get(Rand.Rand());
268 DE = MakeDictionaryEntryFromCMP(X.A, X.B, Data, Size);
269 } break;
270 default:
271 assert(0)((0) ? static_cast<void> (0) : __assert_fail ("0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 271, __PRETTY_FUNCTION__))
;
272 }
273 if (!DE.GetW().size()) return 0;
274 Size = ApplyDictionaryEntry(Data, Size, MaxSize, DE);
275 if (!Size) return 0;
276 DictionaryEntry &DERef =
277 CmpDictionaryEntriesDeque[CmpDictionaryEntriesDequeIdx++ %
278 kCmpDictionaryEntriesDequeSize];
279 DERef = DE;
280 CurrentDictionaryEntrySequence.push_back(&DERef);
281 return Size;
282}
283
284size_t MutationDispatcher::Mutate_AddWordFromPersistentAutoDictionary(
285 uint8_t *Data, size_t Size, size_t MaxSize) {
286 return AddWordFromDictionary(PersistentAutoDictionary, Data, Size, MaxSize);
287}
288
289size_t MutationDispatcher::AddWordFromDictionary(Dictionary &D, uint8_t *Data,
290 size_t Size, size_t MaxSize) {
291 if (Size > MaxSize) return 0;
292 if (D.empty()) return 0;
293 DictionaryEntry &DE = D[Rand(D.size())];
294 Size = ApplyDictionaryEntry(Data, Size, MaxSize, DE);
295 if (!Size) return 0;
296 DE.IncUseCount();
297 CurrentDictionaryEntrySequence.push_back(&DE);
298 return Size;
299}
300
301// Overwrites part of To[0,ToSize) with a part of From[0,FromSize).
302// Returns ToSize.
303size_t MutationDispatcher::CopyPartOf(const uint8_t *From, size_t FromSize,
304 uint8_t *To, size_t ToSize) {
305 // Copy From[FromBeg, FromBeg + CopySize) into To[ToBeg, ToBeg + CopySize).
306 size_t ToBeg = Rand(ToSize);
307 size_t CopySize = Rand(ToSize - ToBeg) + 1;
308 assert(ToBeg + CopySize <= ToSize)((ToBeg + CopySize <= ToSize) ? static_cast<void> (0
) : __assert_fail ("ToBeg + CopySize <= ToSize", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 308, __PRETTY_FUNCTION__))
;
309 CopySize = std::min(CopySize, FromSize);
310 size_t FromBeg = Rand(FromSize - CopySize + 1);
311 assert(FromBeg + CopySize <= FromSize)((FromBeg + CopySize <= FromSize) ? static_cast<void>
(0) : __assert_fail ("FromBeg + CopySize <= FromSize", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 311, __PRETTY_FUNCTION__))
;
312 memmove(To + ToBeg, From + FromBeg, CopySize);
313 return ToSize;
314}
315
316// Inserts part of From[0,ToSize) into To.
317// Returns new size of To on success or 0 on failure.
318size_t MutationDispatcher::InsertPartOf(const uint8_t *From, size_t FromSize,
319 uint8_t *To, size_t ToSize,
320 size_t MaxToSize) {
321 if (ToSize >= MaxToSize) return 0;
322 size_t AvailableSpace = MaxToSize - ToSize;
323 size_t MaxCopySize = std::min(AvailableSpace, FromSize);
324 size_t CopySize = Rand(MaxCopySize) + 1;
325 size_t FromBeg = Rand(FromSize - CopySize + 1);
326 assert(FromBeg + CopySize <= FromSize)((FromBeg + CopySize <= FromSize) ? static_cast<void>
(0) : __assert_fail ("FromBeg + CopySize <= FromSize", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 326, __PRETTY_FUNCTION__))
;
327 size_t ToInsertPos = Rand(ToSize + 1);
328 assert(ToInsertPos + CopySize <= MaxToSize)((ToInsertPos + CopySize <= MaxToSize) ? static_cast<void
> (0) : __assert_fail ("ToInsertPos + CopySize <= MaxToSize"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 328, __PRETTY_FUNCTION__))
;
329 size_t TailSize = ToSize - ToInsertPos;
330 if (To == From) {
331 MutateInPlaceHere.resize(MaxToSize);
332 memcpy(MutateInPlaceHere.data(), From + FromBeg, CopySize);
333 memmove(To + ToInsertPos + CopySize, To + ToInsertPos, TailSize);
334 memmove(To + ToInsertPos, MutateInPlaceHere.data(), CopySize);
335 } else {
336 memmove(To + ToInsertPos + CopySize, To + ToInsertPos, TailSize);
337 memmove(To + ToInsertPos, From + FromBeg, CopySize);
338 }
339 return ToSize + CopySize;
340}
341
342size_t MutationDispatcher::Mutate_CopyPart(uint8_t *Data, size_t Size,
343 size_t MaxSize) {
344 if (Size > MaxSize || Size == 0) return 0;
345 if (Rand.RandBool())
346 return CopyPartOf(Data, Size, Data, Size);
347 else
348 return InsertPartOf(Data, Size, Data, Size, MaxSize);
349}
350
351size_t MutationDispatcher::Mutate_ChangeASCIIInteger(uint8_t *Data, size_t Size,
352 size_t MaxSize) {
353 if (Size > MaxSize) return 0;
354 size_t B = Rand(Size);
355 while (B < Size && !isdigit(Data[B])) B++;
356 if (B == Size) return 0;
357 size_t E = B;
358 while (E < Size && isdigit(Data[E])) E++;
359 assert(B < E)((B < E) ? static_cast<void> (0) : __assert_fail ("B < E"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 359, __PRETTY_FUNCTION__))
;
360 // now we have digits in [B, E).
361 // strtol and friends don't accept non-zero-teminated data, parse it manually.
362 uint64_t Val = Data[B] - '0';
363 for (size_t i = B + 1; i < E; i++)
364 Val = Val * 10 + Data[i] - '0';
365
366 // Mutate the integer value.
367 switch(Rand(5)) {
368 case 0: Val++; break;
369 case 1: Val--; break;
370 case 2: Val /= 2; break;
371 case 3: Val *= 2; break;
372 case 4: Val = Rand(Val * Val); break;
373 default: assert(0)((0) ? static_cast<void> (0) : __assert_fail ("0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 373, __PRETTY_FUNCTION__))
;
374 }
375 // Just replace the bytes with the new ones, don't bother moving bytes.
376 for (size_t i = B; i < E; i++) {
377 size_t Idx = E + B - i - 1;
378 assert(Idx >= B && Idx < E)((Idx >= B && Idx < E) ? static_cast<void>
(0) : __assert_fail ("Idx >= B && Idx < E", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 378, __PRETTY_FUNCTION__))
;
379 Data[Idx] = (Val % 10) + '0';
380 Val /= 10;
381 }
382 return Size;
383}
384
385template<class T>
386size_t ChangeBinaryInteger(uint8_t *Data, size_t Size, Random &Rand) {
387 if (Size < sizeof(T)) return 0;
388 size_t Off = Rand(Size - sizeof(T) + 1);
389 assert(Off + sizeof(T) <= Size)((Off + sizeof(T) <= Size) ? static_cast<void> (0) :
__assert_fail ("Off + sizeof(T) <= Size", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 389, __PRETTY_FUNCTION__))
;
390 T Val;
391 if (Off < 64 && !Rand(4)) {
392 Val = Size;
393 if (Rand.RandBool())
394 Val = Bswap(Val);
395 } else {
396 memcpy(&Val, Data + Off, sizeof(Val));
397 T Add = Rand(21);
398 Add -= 10;
399 if (Rand.RandBool())
400 Val = Bswap(T(Bswap(Val) + Add)); // Add assuming different endiannes.
401 else
402 Val = Val + Add; // Add assuming current endiannes.
403 if (Add == 0 || Rand.RandBool()) // Maybe negate.
404 Val = -Val;
405 }
406 memcpy(Data + Off, &Val, sizeof(Val));
407 return Size;
408}
409
410size_t MutationDispatcher::Mutate_ChangeBinaryInteger(uint8_t *Data,
411 size_t Size,
412 size_t MaxSize) {
413 if (Size > MaxSize) return 0;
414 switch (Rand(4)) {
415 case 3: return ChangeBinaryInteger<uint64_t>(Data, Size, Rand);
416 case 2: return ChangeBinaryInteger<uint32_t>(Data, Size, Rand);
417 case 1: return ChangeBinaryInteger<uint16_t>(Data, Size, Rand);
418 case 0: return ChangeBinaryInteger<uint8_t>(Data, Size, Rand);
419 default: assert(0)((0) ? static_cast<void> (0) : __assert_fail ("0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 419, __PRETTY_FUNCTION__))
;
420 }
421 return 0;
422}
423
424size_t MutationDispatcher::Mutate_CrossOver(uint8_t *Data, size_t Size,
425 size_t MaxSize) {
426 if (Size > MaxSize) return 0;
427 if (!Corpus || Corpus->size() < 2 || Size == 0) return 0;
428 size_t Idx = Rand(Corpus->size());
429 const Unit &O = (*Corpus)[Idx];
430 if (O.empty()) return 0;
431 MutateInPlaceHere.resize(MaxSize);
432 auto &U = MutateInPlaceHere;
433 size_t NewSize = 0;
434 switch(Rand(3)) {
435 case 0:
436 NewSize = CrossOver(Data, Size, O.data(), O.size(), U.data(), U.size());
437 break;
438 case 1:
439 NewSize = InsertPartOf(O.data(), O.size(), U.data(), U.size(), MaxSize);
440 if (!NewSize)
441 NewSize = CopyPartOf(O.data(), O.size(), U.data(), U.size());
442 break;
443 case 2:
444 NewSize = CopyPartOf(O.data(), O.size(), U.data(), U.size());
445 break;
446 default: assert(0)((0) ? static_cast<void> (0) : __assert_fail ("0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 446, __PRETTY_FUNCTION__))
;
447 }
448 assert(NewSize > 0 && "CrossOver returned empty unit")((NewSize > 0 && "CrossOver returned empty unit") ?
static_cast<void> (0) : __assert_fail ("NewSize > 0 && \"CrossOver returned empty unit\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 448, __PRETTY_FUNCTION__))
;
449 assert(NewSize <= MaxSize && "CrossOver returned overisized unit")((NewSize <= MaxSize && "CrossOver returned overisized unit"
) ? static_cast<void> (0) : __assert_fail ("NewSize <= MaxSize && \"CrossOver returned overisized unit\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 449, __PRETTY_FUNCTION__))
;
450 memcpy(Data, U.data(), NewSize);
451 return NewSize;
452}
453
454void MutationDispatcher::StartMutationSequence() {
455 CurrentMutatorSequence.clear();
456 CurrentDictionaryEntrySequence.clear();
457}
458
459// Copy successful dictionary entries to PersistentAutoDictionary.
460void MutationDispatcher::RecordSuccessfulMutationSequence() {
461 for (auto DE : CurrentDictionaryEntrySequence) {
462 // PersistentAutoDictionary.AddWithSuccessCountOne(DE);
463 DE->IncSuccessCount();
464 assert(DE->GetW().size())((DE->GetW().size()) ? static_cast<void> (0) : __assert_fail
("DE->GetW().size()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 464, __PRETTY_FUNCTION__))
;
465 // Linear search is fine here as this happens seldom.
466 if (!PersistentAutoDictionary.ContainsWord(DE->GetW()))
467 PersistentAutoDictionary.push_back({DE->GetW(), 1});
468 }
469}
470
471void MutationDispatcher::PrintRecommendedDictionary() {
472 std::vector<DictionaryEntry> V;
473 for (auto &DE : PersistentAutoDictionary)
474 if (!ManualDictionary.ContainsWord(DE.GetW()))
475 V.push_back(DE);
476 if (V.empty()) return;
477 Printf("###### Recommended dictionary. ######\n");
478 for (auto &DE: V) {
479 assert(DE.GetW().size())((DE.GetW().size()) ? static_cast<void> (0) : __assert_fail
("DE.GetW().size()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 479, __PRETTY_FUNCTION__))
;
480 Printf("\"");
481 PrintASCII(DE.GetW(), "\"");
482 Printf(" # Uses: %zd\n", DE.GetUseCount());
483 }
484 Printf("###### End of recommended dictionary. ######\n");
485}
486
487void MutationDispatcher::PrintMutationSequence() {
488 Printf("MS: %zd ", CurrentMutatorSequence.size());
489 for (auto M : CurrentMutatorSequence)
490 Printf("%s-", M.Name);
491 if (!CurrentDictionaryEntrySequence.empty()) {
492 Printf(" DE: ");
493 for (auto DE : CurrentDictionaryEntrySequence) {
494 Printf("\"");
495 PrintASCII(DE->GetW(), "\"-");
496 }
497 }
498}
499
500size_t MutationDispatcher::Mutate(uint8_t *Data, size_t Size, size_t MaxSize) {
501 return MutateImpl(Data, Size, MaxSize, Mutators);
502}
503
504size_t MutationDispatcher::DefaultMutate(uint8_t *Data, size_t Size,
505 size_t MaxSize) {
506 return MutateImpl(Data, Size, MaxSize, DefaultMutators);
507}
508
509// Mutates Data in place, returns new size.
510size_t MutationDispatcher::MutateImpl(uint8_t *Data, size_t Size,
511 size_t MaxSize,
512 const std::vector<Mutator> &Mutators) {
513 assert(MaxSize > 0)((MaxSize > 0) ? static_cast<void> (0) : __assert_fail
("MaxSize > 0", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303041/lib/Fuzzer/FuzzerMutate.cpp"
, 513, __PRETTY_FUNCTION__))
;
514 // Some mutations may fail (e.g. can't insert more bytes if Size == MaxSize),
515 // in which case they will return 0.
516 // Try several times before returning un-mutated data.
517 for (int Iter = 0; Iter < 100; Iter++) {
518 auto M = Mutators[Rand(Mutators.size())];
519 size_t NewSize = (this->*(M.Fn))(Data, Size, MaxSize);
520 if (NewSize && NewSize <= MaxSize) {
521 if (Options.OnlyASCII)
522 ToASCII(Data, NewSize);
523 CurrentMutatorSequence.push_back(M);
524 return NewSize;
525 }
526 }
527 *Data = ' ';
528 return 1; // Fallback, should not happen frequently.
529}
530
531void MutationDispatcher::AddWordToManualDictionary(const Word &W) {
532 ManualDictionary.push_back(
533 {W, std::numeric_limits<size_t>::max()});
534}
535
536void MutationDispatcher::AddWordToAutoDictionary(DictionaryEntry DE) {
537 static const size_t kMaxAutoDictSize = 1 << 14;
538 if (TempAutoDictionary.size() >= kMaxAutoDictSize) return;
539 TempAutoDictionary.push_back(DE);
540}
541
542void MutationDispatcher::ClearAutoDictionary() {
543 TempAutoDictionary.clear();
544}
545
546} // namespace fuzzer