// Copyright (c) 2020 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.

#ifndef SOURCE_FUZZ_COMPARATOR_BLOCKS_DEEP_FIRST_H_
#define SOURCE_FUZZ_COMPARATOR_BLOCKS_DEEP_FIRST_H_

#include "source/fuzz/fuzzer_util.h"
#include "source/opt/ir_context.h"

namespace spvtools {
namespace fuzz {

// Comparator for blocks, comparing them based on how deep they are nested
// inside selection or loop constructs. Deeper blocks are considered less than
// ones that are not as deep. The blocks are required to be in the same
// function.
class ComparatorDeepBlocksFirst {
 public:
  explicit ComparatorDeepBlocksFirst(opt::IRContext* ir_context)
      : ir_context_(ir_context) {}

  bool operator()(uint32_t bb1, uint32_t bb2) const {
    return this->operator()(fuzzerutil::MaybeFindBlock(ir_context_, bb1),
                            fuzzerutil::MaybeFindBlock(ir_context_, bb2));
  }

  bool operator()(const opt::BasicBlock* bb1, opt::BasicBlock* bb2) const {
    assert(bb1 && bb2 && "The blocks must exist.");
    assert(bb1->GetParent() == bb2->GetParent() &&
           "The blocks must be in the same functions.");
    return ir_context_->GetStructuredCFGAnalysis()->NestingDepth(bb1->id()) >
           ir_context_->GetStructuredCFGAnalysis()->NestingDepth(bb2->id());
  }

 private:
  opt::IRContext* ir_context_;
};

}  // namespace fuzz
}  // namespace spvtools

#endif  // SOURCE_FUZZ_COMPARATOR_BLOCKS_DEEP_FIRST_H_