// Copyright (c) 2019 Google LLC // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include "source/fuzz/fuzzer_context.h" #include namespace spvtools { namespace fuzz { namespace { // Default pairs of probabilities for applying various // transformations. All values are percentages. Keep them in alphabetical order. const std::pair kChanceOfAddingDeadBreak = {5, 80}; const std::pair kChanceOfAddingDeadContinue = {5, 80}; const std::pair kChanceOfCopyingObject = {20, 50}; const std::pair kChanceOfMovingBlockDown = {20, 50}; const std::pair kChanceOfObfuscatingConstant = {10, 90}; const std::pair kChanceOfReplacingIdWithSynonym = {10, 90}; const std::pair kChanceOfSplittingBlock = {40, 95}; // Default functions for controlling how deep to go during recursive // generation/transformation. Keep them in alphabetical order. const std::function kDefaultGoDeeperInConstantObfuscation = [](uint32_t current_depth, RandomGenerator* random_generator) -> bool { double chance = 1.0 / std::pow(3.0, static_cast(current_depth + 1)); return random_generator->RandomDouble() < chance; }; } // namespace FuzzerContext::FuzzerContext(RandomGenerator* random_generator, uint32_t min_fresh_id) : random_generator_(random_generator), next_fresh_id_(min_fresh_id), go_deeper_in_constant_obfuscation_( kDefaultGoDeeperInConstantObfuscation) { chance_of_adding_dead_break_ = ChooseBetweenMinAndMax(kChanceOfAddingDeadBreak); chance_of_adding_dead_continue_ = ChooseBetweenMinAndMax(kChanceOfAddingDeadContinue); chance_of_copying_object_ = ChooseBetweenMinAndMax(kChanceOfCopyingObject); chance_of_moving_block_down_ = ChooseBetweenMinAndMax(kChanceOfMovingBlockDown); chance_of_obfuscating_constant_ = ChooseBetweenMinAndMax(kChanceOfObfuscatingConstant); chance_of_replacing_id_with_synonym_ = ChooseBetweenMinAndMax(kChanceOfReplacingIdWithSynonym); chance_of_splitting_block_ = ChooseBetweenMinAndMax(kChanceOfSplittingBlock); } FuzzerContext::~FuzzerContext() = default; uint32_t FuzzerContext::GetFreshId() { return next_fresh_id_++; } bool FuzzerContext::ChooseEven() { return random_generator_->RandomBool(); } bool FuzzerContext::ChoosePercentage(uint32_t percentage_chance) { assert(percentage_chance <= 100); return random_generator_->RandomPercentage() < percentage_chance; } uint32_t FuzzerContext::ChooseBetweenMinAndMax( const std::pair& min_max) { assert(min_max.first <= min_max.second); return min_max.first + random_generator_->RandomUint32(min_max.second - min_max.first + 1); } } // namespace fuzz } // namespace spvtools