1 //===- FuzzerCrossOver.cpp - Cross over two test inputs -------------------===// 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 // Cross over test inputs. 10 //===----------------------------------------------------------------------===// 11 12 #include "FuzzerInternal.h" 13 #include <algorithm> 14 15 namespace fuzzer { 16 17 // Cross A and B, store the result (ap to MaxLen bytes) in U. 18 void CrossOver(const Unit &A, const Unit &B, Unit *U, size_t MaxLen) { 19 size_t Size = rand() % MaxLen + 1; 20 U->clear(); 21 const Unit *V = &A; 22 size_t PosA = 0; 23 size_t PosB = 0; 24 size_t *Pos = &PosA; 25 while (U->size() < Size && (PosA < A.size() || PosB < B.size())) { 26 // Merge a part of V into U. 27 size_t SizeLeftU = Size - U->size(); 28 if (*Pos < V->size()) { 29 size_t SizeLeftV = V->size() - *Pos; 30 size_t MaxExtraSize = std::min(SizeLeftU, SizeLeftV); 31 size_t ExtraSize = rand() % MaxExtraSize + 1; 32 U->insert(U->end(), V->begin() + *Pos, V->begin() + *Pos + ExtraSize); 33 (*Pos) += ExtraSize; 34 } 35 36 // Use the other Unit on the next iteration. 37 if (Pos == &PosA) { 38 Pos = &PosB; 39 V = &B; 40 } else { 41 Pos = &PosA; 42 V = &A; 43 } 44 } 45 } 46 47 } // namespace fuzzer 48
