text: // Copyright (c) 2021 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 <cstdint>
  #include <vector>
  
  #include "source/fuzz/fuzzer.h"
  #include "source/fuzz/pseudo_random_generator.h"
  #include "spirv-tools/libspirv.hpp"
  #include "test/fuzzers/random_generator.h"
  
  extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
    if (size == 0 || (size % sizeof(uint32_t)) != 0) {
      // An empty binary, or a binary whose size is not a multiple of word-size,
      // cannot be valid, so can be rejected immediately.
      return 0;
    }
  
    std::vector<uint32_t> initial_binary(size / sizeof(uint32_t));
    memcpy(initial_binary.data(), data, size);
  
    spvtools::ValidatorOptions validator_options;
  
    spvtools::MessageConsumer message_consumer =
        [](spv_message_level_t, const char*, const spv_position_t&, const char*) {
        };
  
    spvtools::fuzzers::RandomGenerator random_gen(data, size);
    auto target_env = random_gen.GetTargetEnv();
    std::unique_ptr<spvtools::opt::IRContext> ir_context;
    if (!spvtools::fuzz::fuzzerutil::BuildIRContext(
            target_env, message_consumer, initial_binary, validator_options,
            &ir_context)) {
      // The input is invalid - give up.
      return 0;
    }
  
    std::vector<spvtools::fuzz::fuzzerutil::ModuleSupplier> donor_suppliers = {
        [&initial_binary, message_consumer, target_env,
         &validator_options]() -> std::unique_ptr<spvtools::opt::IRContext> {
          std::unique_ptr<spvtools::opt::IRContext> result;
          if (!spvtools::fuzz::fuzzerutil::BuildIRContext(
                  target_env, message_consumer, initial_binary, validator_options,
                  &result)) {
            // The input was successfully parsed and validated first time around,
            // so something is wrong if it is now invalid.
            abort();
          }
          return result;
        }};
  
    uint32_t seed = random_gen.GetUInt32(std::numeric_limits<uint32_t>::max());
    auto fuzzer_context = spvtools::MakeUnique<spvtools::fuzz::FuzzerContext>(
        spvtools::MakeUnique<spvtools::fuzz::PseudoRandomGenerator>(seed),
        spvtools::fuzz::FuzzerContext::GetMinFreshId(ir_context.get()), false);
  
    auto transformation_context =
        spvtools::MakeUnique<spvtools::fuzz::TransformationContext>(
            spvtools::MakeUnique<spvtools::fuzz::FactManager>(ir_context.get()),
            validator_options);
  
    spvtools::fuzz::Fuzzer fuzzer(
        std::move(ir_context), std::move(transformation_context),
        std::move(fuzzer_context), message_consumer, donor_suppliers, false,
        spvtools::fuzz::RepeatedPassStrategy::kLoopedWithRecommendations, true,
        validator_options);
    fuzzer.Run(0);
    return 0;
  }
  