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

#pragma once

#include <optional>
#include <string>
#include <unordered_map>
#include <vector>

namespace ir {
class Function;
class Value;
}

enum class SemanticType {
  Void,
  Int,
  Float,
};

enum class SymbolKind {
  Variable,
  Constant,
  Function,
};

struct ConstantValue {
  SemanticType type = SemanticType::Int;
  int int_value = 0;
  float float_value = 0.0f;
};

struct FunctionTypeInfo {
  SemanticType return_type = SemanticType::Void;
  std::vector<SemanticType> param_types;
  std::vector<bool> param_is_array;
  std::vector<std::vector<int>> param_dims;
};

struct SymbolEntry {
  SymbolKind kind = SymbolKind::Variable;
  SemanticType type = SemanticType::Int;
  bool is_const = false;
  bool is_array = false;
  bool is_param_array = false;
  std::vector<int> dims;

  ir::Value* ir_value = nullptr;
  ir::Function* function = nullptr;

  std::optional<ConstantValue> const_scalar;
  std::vector<ConstantValue> const_array;
  FunctionTypeInfo function_type;
};

class SymbolTable {
 public:
  void Clear();
  void EnterScope();
  void ExitScope();

  bool Insert(const std::string& name, const SymbolEntry& entry);
  bool ContainsInCurrentScope(const std::string& name) const;

  SymbolEntry* Lookup(const std::string& name);
  const SymbolEntry* Lookup(const std::string& name) const;

 private:
  std::vector<std::unordered_map<std::string, SymbolEntry>> scopes_;
};