// Copyright (c) 2018 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/opt/strip_reflect_info_pass.h"

#include <cstring>
#include <vector>

#include "source/opt/instruction.h"
#include "source/opt/ir_context.h"

namespace spvtools {
namespace opt {

Pass::Status StripReflectInfoPass::Process() {
  bool modified = false;

  std::vector<Instruction*> to_remove;

  bool other_uses_for_decorate_string = false;
  for (auto& inst : context()->module()->annotations()) {
    switch (inst.opcode()) {
      case SpvOpDecorateStringGOOGLE:
        if (inst.GetSingleWordInOperand(1) == SpvDecorationHlslSemanticGOOGLE) {
          to_remove.push_back(&inst);
        } else {
          other_uses_for_decorate_string = true;
        }
        break;

      case SpvOpMemberDecorateStringGOOGLE:
        if (inst.GetSingleWordInOperand(2) == SpvDecorationHlslSemanticGOOGLE) {
          to_remove.push_back(&inst);
        } else {
          other_uses_for_decorate_string = true;
        }
        break;

      case SpvOpDecorateId:
        if (inst.GetSingleWordInOperand(1) ==
            SpvDecorationHlslCounterBufferGOOGLE) {
          to_remove.push_back(&inst);
        }
        break;

      default:
        break;
    }
  }

  for (auto& inst : context()->module()->extensions()) {
    const char* ext_name =
        reinterpret_cast<const char*>(&inst.GetInOperand(0).words[0]);
    if (0 == std::strcmp(ext_name, "SPV_GOOGLE_hlsl_functionality1")) {
      to_remove.push_back(&inst);
    } else if (!other_uses_for_decorate_string &&
               0 == std::strcmp(ext_name, "SPV_GOOGLE_decorate_string")) {
      to_remove.push_back(&inst);
    }
  }

  for (auto* inst : to_remove) {
    modified = true;
    context()->KillInst(inst);
  }

  return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}

}  // namespace opt
}  // namespace spvtools