forked from OSchip/llvm-project
48 lines
1.4 KiB
C++
48 lines
1.4 KiB
C++
//===- FuzzerCrossOver.cpp - Cross over two test inputs -------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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// Cross over test inputs.
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//===----------------------------------------------------------------------===//
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#include "FuzzerInternal.h"
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#include <algorithm>
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namespace fuzzer {
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// Cross A and B, store the result (ap to MaxLen bytes) in U.
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void CrossOver(const Unit &A, const Unit &B, Unit *U, size_t MaxLen) {
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size_t Size = rand() % MaxLen + 1;
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U->clear();
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const Unit *V = &A;
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size_t PosA = 0;
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size_t PosB = 0;
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size_t *Pos = &PosA;
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while (U->size() < Size && (PosA < A.size() || PosB < B.size())) {
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// Merge a part of V into U.
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size_t SizeLeftU = Size - U->size();
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if (*Pos < V->size()) {
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size_t SizeLeftV = V->size() - *Pos;
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size_t MaxExtraSize = std::min(SizeLeftU, SizeLeftV);
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size_t ExtraSize = rand() % MaxExtraSize + 1;
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U->insert(U->end(), V->begin() + *Pos, V->begin() + *Pos + ExtraSize);
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(*Pos) += ExtraSize;
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}
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// Use the other Unit on the next iteration.
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if (Pos == &PosA) {
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Pos = &PosB;
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V = &B;
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} else {
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Pos = &PosA;
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V = &A;
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}
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}
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}
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} // namespace fuzzer
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