nudt-compiler-cpp/include/sem/Sema.h

// 基于语法树的语义检查与名称绑定。
#pragma once

#include <unordered_map>

#include "SysYParser.h"

class SemanticContext {
 public:
  void BindVarUse(SysYParser::LValContext* use,
                  SysYParser::VarDefContext* decl) {
    var_uses_[use] = decl;
  }

  SysYParser::VarDefContext* ResolveVarUse(
      const SysYParser::LValContext* use) const {
    auto it = var_uses_.find(use);
    return it == var_uses_.end() ? nullptr : it->second;
  }

  void BindConstArrayUse(SysYParser::LValContext* use,
                         SysYParser::ConstDefContext* decl) {
    const_array_uses_[use] = decl;
  }

  SysYParser::ConstDefContext* ResolveConstArrayUse(
      const SysYParser::LValContext* use) const {
    auto it = const_array_uses_.find(use);
    return it == const_array_uses_.end() ? nullptr : it->second;
  }

  void BindConstScalarUse(SysYParser::LValContext* use,
                          SysYParser::ConstDefContext* decl) {
    const_scalar_uses_[use] = decl;
  }

  SysYParser::ConstDefContext* ResolveConstScalarUse(
      const SysYParser::LValContext* use) const {
    auto it = const_scalar_uses_.find(use);
    return it == const_scalar_uses_.end() ? nullptr : it->second;
  }

  void BindConstUse(SysYParser::LValContext* use, int value) {
    const_uses_[use] = value;
  }

  const int* ResolveConstUse(const SysYParser::LValContext* use) const {
    auto it = const_uses_.find(use);
    return it == const_uses_.end() ? nullptr : &it->second;
  }

  void BindConstFloatUse(SysYParser::LValContext* use, double value) {
    const_float_uses_[use] = value;
  }

  const double* ResolveConstFloatUse(const SysYParser::LValContext* use) const {
    auto it = const_float_uses_.find(use);
    return it == const_float_uses_.end() ? nullptr : &it->second;
  }

  void BindCallUse(SysYParser::UnaryExpContext* call,
                   SysYParser::FuncDefContext* decl) {
    call_uses_[call] = decl;
  }

  SysYParser::FuncDefContext* ResolveCallUse(
      const SysYParser::UnaryExpContext* call) const {
    auto it = call_uses_.find(call);
    return it == call_uses_.end() ? nullptr : it->second;
  }

 private:
  std::unordered_map<const SysYParser::LValContext*,
                     SysYParser::VarDefContext*>
      var_uses_;
  std::unordered_map<const SysYParser::LValContext*, int> const_uses_;
  std::unordered_map<const SysYParser::LValContext*, double> const_float_uses_;
  std::unordered_map<const SysYParser::LValContext*,
                     SysYParser::ConstDefContext*>
      const_array_uses_;
  std::unordered_map<const SysYParser::LValContext*,
                     SysYParser::ConstDefContext*>
      const_scalar_uses_;
  std::unordered_map<const SysYParser::UnaryExpContext*,
                     SysYParser::FuncDefContext*>
      call_uses_;
};

// 目前仅检查：
// - 变量先声明后使用
// - 局部变量不允许重复定义
SemanticContext RunSema(SysYParser::CompUnitContext& comp_unit);