// 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.

#ifndef SOURCE_OPT_WRAP_OPKILL_H_

#define SOURCE_OPT_WRAP_OPKILL_H_

#include "source/opt/pass.h"

namespace spvtools {

namespace opt {

// Documented in optimizer.hpp

class WrapOpKill : public Pass {

 public:

  WrapOpKill() : void_type_id_(0) {}

  const char* name() const override { return "wrap-opkill"; }

  Status Process() override;

  IRContext::Analysis GetPreservedAnalyses() override {

    return IRContext::kAnalysisDefUse |

           IRContext::kAnalysisInstrToBlockMapping |

           IRContext::kAnalysisDecorations | IRContext::kAnalysisCombinators |

           IRContext::kAnalysisNameMap | IRContext::kAnalysisBuiltinVarId |

           IRContext::kAnalysisConstants | IRContext::kAnalysisTypes;

  }

 private:

  // Replaces the OpKill or OpTerminateInvocation instruction |inst| with a

  // function call to a function that contains a single instruction, a clone of

  // |inst|.  An OpUnreachable instruction will be placed after the function

  // call. Return true if successful.

  bool ReplaceWithFunctionCall(Instruction* inst);

  // Returns the id of the void type.

  uint32_t GetVoidTypeId();

  // Returns the id of the function type for a void function with no parameters.

  uint32_t GetVoidFunctionTypeId();

  // Return the id of a function that has return type void, has no parameters,

  // and contains a single instruction, which is |opcode|, either OpKill or

  // OpTerminateInvocation.  Returns 0 if the function could not be generated.

  uint32_t GetKillingFuncId(spv::Op opcode);

  // Returns the id of the return type for the function that contains |inst|.

  // Returns 0 if |inst| is not in a function.

  uint32_t GetOwningFunctionsReturnType(Instruction* inst);

  // The id of the void type.  If its value is 0, then the void type has not

  // been found or created yet.

  uint32_t void_type_id_;

  // The function that is a single instruction, which is an OpKill.  The

  // function has a void return type and takes no parameters. If the function is

  // |nullptr|, then the function has not been generated.

  std::unique_ptr<Function> opkill_function_;

  // The function that is a single instruction, which is an

  // OpTerminateInvocation. The function has a void return type and takes no

  // parameters. If the function is |nullptr|, then the function has not been

  // generated.

  std::unique_ptr<Function> opterminateinvocation_function_;

};

}  // namespace opt

}  // namespace spvtools

#endif  // SOURCE_OPT_WRAP_OPKILL_H_