source/fuzz/pass_management/repeated_pass_manager_looped_with_recommendations.cpp

   1 // Copyright (c) 2020 Google LLC
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 #include "source/fuzz/pass_management/repeated_pass_manager_looped_with_recommendations.h"
  16
  17 namespace spvtools {
  18 namespace fuzz {
  19
  20 RepeatedPassManagerLoopedWithRecommendations::
  21     RepeatedPassManagerLoopedWithRecommendations(
  22         FuzzerContext* fuzzer_context, RepeatedPassInstances* pass_instances,
  23         RepeatedPassRecommender* pass_recommender)
  24     : RepeatedPassManager(fuzzer_context, pass_instances),
  25       num_transformations_applied_before_last_pass_choice_(0),
  26       next_pass_index_(0) {
  27   auto& passes = GetPassInstances()->GetPasses();
  28   do {
  29     FuzzerPass* current_pass =
  30         passes[GetFuzzerContext()->RandomIndex(passes)].get();
  31     pass_loop_.push_back(current_pass);
  32     for (auto future_pass :
  33          pass_recommender->GetFuturePassRecommendations(*current_pass)) {
  34       recommended_pass_indices_.insert(
  35           static_cast<uint32_t>(pass_loop_.size()));
  36       pass_loop_.push_back(future_pass);
  37     }
  38   } while (fuzzer_context->ChoosePercentage(
  39       fuzzer_context->GetChanceOfAddingAnotherPassToPassLoop()));
  40 }
  41
  42 RepeatedPassManagerLoopedWithRecommendations::
  43     ~RepeatedPassManagerLoopedWithRecommendations() = default;
  44
  45 FuzzerPass* RepeatedPassManagerLoopedWithRecommendations::ChoosePass(
  46     const protobufs::TransformationSequence& applied_transformations) {
  47   assert((next_pass_index_ > 0 ||
  48           recommended_pass_indices_.count(next_pass_index_) == 0) &&
  49          "The first pass in the loop should not be a recommendation.");
  50   assert(static_cast<uint32_t>(applied_transformations.transformation_size()) >=
  51              num_transformations_applied_before_last_pass_choice_ &&
  52          "The number of applied transformations should not decrease.");
  53   if (num_transformations_applied_before_last_pass_choice_ ==
  54       static_cast<uint32_t>(applied_transformations.transformation_size())) {
  55     // The last pass that was applied did not lead to any new transformations.
  56     // We thus do not want to apply recommendations based on it, so we skip on
  57     // to the next non-recommended pass.
  58     while (recommended_pass_indices_.count(next_pass_index_)) {
  59       next_pass_index_ =
  60           (next_pass_index_ + 1) % static_cast<uint32_t>(pass_loop_.size());
  61     }
  62   }
  63   auto result = pass_loop_[next_pass_index_];
  64   next_pass_index_ =
  65       (next_pass_index_ + 1) % static_cast<uint32_t>(pass_loop_.size());
  66   return result;
  67 }
  68
  69 }  // namespace fuzz
  70 }  // namespace spvtools