Complete Lab2 IR generation and document process

include/sem/SymbolTable.h

@@ -1,17 +1,30 @@
-// 极简符号表：记录局部变量定义点。
 #pragma once
 
 #include <string>
 #include <unordered_map>
+#include <vector>
 
 #include "SysYParser.h"
 
+struct Symbol {
+  enum class Kind { Variable, Constant, Function, Parameter };
+  Kind kind;
+  antlr4::ParserRuleContext* def_ctx;
+  bool is_const = false;
+  bool is_array = false;
+  // For functions, we can store pointers to their parameter types or just the
+  // FuncDefContext*
+};
+
 class SymbolTable {
  public:
-  void Add(const std::string& name, SysYParser::VarDefContext* decl);
-  bool Contains(const std::string& name) const;
-  SysYParser::VarDefContext* Lookup(const std::string& name) const;
+  SymbolTable();
+  void PushScope();
+  void PopScope();
+  bool Add(const std::string& name, const Symbol& symbol);
+  Symbol* Lookup(const std::string& name);
+  bool IsInCurrentScope(const std::string& name) const;
 
  private:
-  std::unordered_map<std::string, SysYParser::VarDefContext*> table_;
+  std::vector<std::unordered_map<std::string, Symbol>> scopes_;
 };