src/semantic/info.h

// Copyright 2021 The Tint Authors.
//
// 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 SRC_SEMANTIC_INFO_H_
#define SRC_SEMANTIC_INFO_H_

#include <assert.h>

#include <unordered_map>

#include "src/semantic/node.h"
#include "src/semantic/type_mappings.h"

namespace tint {

// Forward declarations
namespace ast {
class Node;
}  // namespace ast

namespace semantic {

/// Info holds all the resolved semantic information for a Program.
class Info {
 public:
  /// Constructor
  Info();

  /// Move constructor
  Info(Info&&);

  /// Destructor
  ~Info();

  /// Move assignment operator
  /// @param rhs the Program to move
  /// @return this Program
  Info& operator=(Info&& rhs);

  /// Get looks up the semantic information for the AST node `ast_node`.
  /// @param ast_node the AST node
  /// @returns a pointer to the semantic node if found, otherwise nullptr
  template <typename AST, typename SEM = SemanticNodeTypeFor<AST>>
  const SEM* Get(const AST* ast_node) const {
    auto it = ast_to_sem_.find(ast_node);
    if (it == ast_to_sem_.end()) {
      return nullptr;
    }
    return it->second->template As<SEM>();
  }

  /// Add registers the semantic node `sem_node` for the AST node `ast_node`.
  /// @param ast_node the AST node
  /// @param sem_node the semantic node
  template <typename AST>
  void Add(const AST* ast_node, const SemanticNodeTypeFor<AST>* sem_node) {
    // Check there's no semantic info already existing for the node
    assert(Get(ast_node) == nullptr);
    ast_to_sem_.emplace(ast_node, sem_node);
  }

  /// Wrap returns a new Info created with the contents of `inner`.
  /// The Info returned by Wrap is intended to temporarily extend the contents
  /// of an existing immutable Info.
  /// As the copied contents are owned by `inner`, `inner` must not be
  /// destructed or assigned while using the returned Info.
  /// @param inner the immutable Info to extend
  /// @return the Info that wraps `inner`
  static Info Wrap(const Info& inner) {
    Info out;
    out.ast_to_sem_ = inner.ast_to_sem_;
    return out;
  }

 private:
  std::unordered_map<const ast::Node*, const semantic::Node*> ast_to_sem_;
};

}  // namespace semantic
}  // namespace tint

#endif  // SRC_SEMANTIC_INFO_H_