mirror of
https://github.com/KhronosGroup/SPIRV-Tools
synced 2024-10-18 19:20:05 +00:00
e2e95172df
Before this change there was quite a lot of duplication in the code being used to choose random percentages, and some of it was incorrect so that a percentage chance of (100-N)% instead of N% was being used. Also there was a lot of duplicate code to choose a random index into a vector. This change eliminates that duplication (fixing up the percentage problem), and gets rid of direct access to the random number generator being used for fuzzing, so that all randomization requests must go through the FuzzerContext class, discouraging future ad-hoc uses of the random number generator.
70 lines
2.6 KiB
C++
70 lines
2.6 KiB
C++
// 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 <cmath>
|
|
|
|
namespace spvtools {
|
|
namespace fuzz {
|
|
|
|
namespace {
|
|
// Default probabilities for applying various transformations.
|
|
// All values are percentages.
|
|
// Keep them in alphabetical order.
|
|
|
|
const uint32_t kDefaultChanceOfAddingDeadBreak = 20;
|
|
const uint32_t kDefaultChanceOfAddingDeadContinue = 20;
|
|
const uint32_t kDefaultChanceOfMovingBlockDown = 25;
|
|
const uint32_t kDefaultChanceOfObfuscatingConstant = 20;
|
|
const uint32_t kDefaultChanceOfSplittingBlock = 20;
|
|
|
|
// Default functions for controlling how deep to go during recursive
|
|
// generation/transformation. Keep them in alphabetical order.
|
|
|
|
const std::function<bool(uint32_t, RandomGenerator*)>
|
|
kDefaultGoDeeperInConstantObfuscation =
|
|
[](uint32_t current_depth, RandomGenerator* random_generator) -> bool {
|
|
double chance = 1.0 / std::pow(3.0, static_cast<float>(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),
|
|
chance_of_adding_dead_break_(kDefaultChanceOfAddingDeadBreak),
|
|
chance_of_adding_dead_continue_(kDefaultChanceOfAddingDeadContinue),
|
|
chance_of_moving_block_down_(kDefaultChanceOfMovingBlockDown),
|
|
chance_of_obfuscating_constant_(kDefaultChanceOfObfuscatingConstant),
|
|
chance_of_splitting_block_(kDefaultChanceOfSplittingBlock),
|
|
go_deeper_in_constant_obfuscation_(
|
|
kDefaultGoDeeperInConstantObfuscation) {}
|
|
|
|
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;
|
|
}
|
|
|
|
} // namespace fuzz
|
|
} // namespace spvtools
|