refactor(ir): 改一下sema相关的适配

src/sem/Sema.cpp

@@ -11,57 +11,74 @@ namespace {
 void CheckExpr(SysYParser::ExpContext& exp, const SymbolTable& table,
                SemanticContext& sema);
 
-void CheckPrimary(SysYParser::PrimaryContext& primary,
-                  const SymbolTable& table, SemanticContext& sema) {
-  if (primary.Number()) {
-    return;
+std::string GetLValueName(SysYParser::LValueContext& lvalue) {
+  if (!lvalue.ID()) {
+    throw std::runtime_error(FormatError("sema", "非法左值"));
+  }
+  return lvalue.ID()->getText();
+}
+
+void CheckVar(SysYParser::VarContext& var, const SymbolTable& table,
+              SemanticContext& sema) {
+  if (!var.ID()) {
+    throw std::runtime_error(FormatError("sema", "非法变量引用"));
+  }
+  const std::string name = var.ID()->getText();
+  auto* decl = table.Lookup(name);
+  if (!decl) {
+    throw std::runtime_error(FormatError("sema", "使用了未定义的变量: " + name));
   }
+  sema.BindVarUse(&var, decl);
+}
 
-  if (primary.Ident()) {
-    const std::string name = primary.Ident()->getText();
-    auto* decl = table.Lookup(name);
-    if (!decl) {
-      throw std::runtime_error(FormatError("sema", "使用了未定义的变量: " + name));
+void CheckExpr(SysYParser::ExpContext& exp, const SymbolTable& table,
+               SemanticContext& sema) {
+  if (auto* paren = dynamic_cast<SysYParser::ParenExpContext*>(&exp)) {
+    CheckExpr(*paren->exp(), table, sema);
+    return;
+  }
+  if (auto* var = dynamic_cast<SysYParser::VarExpContext*>(&exp)) {
+    if (!var->var()) {
+      throw std::runtime_error(FormatError("sema", "非法变量表达式"));
     }
-    sema.BindVarUse(&primary, decl);
+    CheckVar(*var->var(), table, sema);
     return;
   }
-
-  if (primary.exp()) {
-    CheckExpr(*primary.exp(), table, sema);
+  if (dynamic_cast<SysYParser::NumberExpContext*>(&exp)) {
+    return;
+  }
+  if (auto* binary = dynamic_cast<SysYParser::AdditiveExpContext*>(&exp)) {
+    CheckExpr(*binary->exp(0), table, sema);
+    CheckExpr(*binary->exp(1), table, sema);
     return;
   }
-
   throw std::runtime_error(FormatError("sema", "暂不支持的表达式形式"));
 }
 
-void CheckExpr(SysYParser::ExpContext& exp, const SymbolTable& table,
-               SemanticContext& sema) {
-  if (!exp.addExp()) {
-    throw std::runtime_error(FormatError("sema", "非法表达式"));
-  }
-  const auto& terms = exp.addExp()->primary();
-  for (auto* term : terms) {
-    CheckPrimary(*term, table, sema);
+SysYParser::FuncDefContext* FindMainFunc(SysYParser::CompUnitContext& comp_unit) {
+  auto* func = comp_unit.funcDef();
+  if (func && func->ID() && func->ID()->getText() == "main") {
+    return func;
   }
+  return nullptr;
 }
 
 }  // namespace
 
 SemanticContext RunSema(SysYParser::CompUnitContext& comp_unit) {
-  auto* func = comp_unit.funcDef();
-  if (!func || !func->block()) {
+  auto* func = FindMainFunc(comp_unit);
+  if (!func || !func->blockStmt()) {
     throw std::runtime_error(FormatError("sema", "缺少 main 函数定义"));
   }
-  if (!func->Ident() || func->Ident()->getText() != "main") {
-    throw std::runtime_error(FormatError("sema", "入口函数必须命名为 main"));
+  if (!func->funcType() || !func->funcType()->INT()) {
+    throw std::runtime_error(FormatError("sema", "当前仅支持 int main"));
   }
 
   SymbolTable table;
   SemanticContext sema;
   bool seen_return = false;
 
-  const auto& items = func->block()->blockItem();
+  const auto& items = func->blockStmt()->blockItem();
   if (items.empty()) {
     throw std::runtime_error(
         FormatError("sema", "main 函数不能为空，且必须以 return 结束"));
@@ -76,19 +93,33 @@ SemanticContext RunSema(SysYParser::CompUnitContext& comp_unit) {
       throw std::runtime_error(
           FormatError("sema", "return 必须是 main 函数中的最后一条语句"));
     }
-    if (auto* decl = item->decl() ? item->decl()->varDecl() : nullptr) {
-      const std::string name = decl->Ident()->getText();
+    if (auto* decl = item->decl()) {
+      if (!decl->btype() || !decl->btype()->INT()) {
+        throw std::runtime_error(FormatError("sema", "当前仅支持局部 int 变量声明"));
+      }
+      auto* var_def = decl->varDef();
+      if (!var_def || !var_def->lValue()) {
+        throw std::runtime_error(FormatError("sema", "非法变量声明"));
+      }
+      const std::string name = GetLValueName(*var_def->lValue());
       if (table.Contains(name)) {
         throw std::runtime_error(FormatError("sema", "重复定义变量: " + name));
       }
-      if (decl->exp()) {
-        CheckExpr(*decl->exp(), table, sema);
+      if (auto* init = var_def->initValue()) {
+        if (!init->exp()) {
+          throw std::runtime_error(
+              FormatError("sema", "当前不支持聚合初始化"));
+        }
+        CheckExpr(*init->exp(), table, sema);
       }
-      table.Add(name, decl);
+      table.Add(name, var_def);
       continue;
     }
     if (auto* stmt = item->stmt(); stmt && stmt->returnStmt()) {
       auto* ret = stmt->returnStmt();
+      if (!ret->exp()) {
+        throw std::runtime_error(FormatError("sema", "return 缺少表达式"));
+      }
       CheckExpr(*ret->exp(), table, sema);
       seen_return = true;
       if (i + 1 != items.size()) {