/*

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */

#ifndef HERMES_OPTIMIZER_PASSMANAGER_PASS_H

#define HERMES_OPTIMIZER_PASSMANAGER_PASS_H

#include "llvh/ADT/StringRef.h"

#include <memory>

namespace hermes {

class Function;

class Module;

class Instruction;

class IRBuilder;

/// This class represents a pass, which is a transformation of the IR. Passes

/// are either Function passes, which transform one function, and are not

/// allowed to create new functions or modify other functions, or module

/// passes which operate on the entire module and are free to manipulate

/// multiple functions.

class Pass {

 public:

  enum class PassKind {

    Function,

    Module,

  };

 private:

  /// Stores the kind of derived class.

  const PassKind kind;

  /// The textual name of the pass.

  llvh::StringRef name;

 public:

  /// Constructor. \p K indicates the kind of pass this is.

  explicit Pass(Pass::PassKind K, llvh::StringRef name) : kind(K), name(name) {}

  virtual ~Pass() = default;

  /// Returns the kind of the pass.

  PassKind getKind() const {

    return kind;

  }

  /// Returns the textual name of the pass.

  llvh::StringRef getName() const {

    return name;

  }

};

class FunctionPass : public Pass {

 public:

  explicit FunctionPass(llvh::StringRef name)

      : Pass(Pass::PassKind::Function, name) {}

  ~FunctionPass() override = default;

  /// Runs the current pass on the function \p F.

  /// \returns true if the function was modified.

  virtual bool runOnFunction(Function *F) = 0;

  static bool classof(const Pass *S) {

    return S->getKind() == PassKind::Function;

  }

};

class ModulePass : public Pass {

 public:

  explicit ModulePass(llvh::StringRef name)

      : Pass(Pass::PassKind::Module, name) {}

  ~ModulePass() override = default;

  /// Runs the current pass on the module \p M.

  /// \returns true if module was modified.

  virtual bool runOnModule(Module *M) = 0;

  static bool classof(const Pass *S) {

    return S->getKind() == PassKind::Module;

  }

};

/// Pass header declaration.

#define PASS(ID, NAME, DESCRIPTION) std::unique_ptr<Pass> create##ID();

#include "Passes.def"

} // namespace hermes

#endif // HERMES_OPTIMIZER_PASSMANAGER_PASS_H