fix(frontend): 规范一下前端实现

src/ir/IR.h

@@ -23,7 +23,7 @@ class Context {
   const std::shared_ptr<Type>& PtrInt32();
   // 去重创建 i32 常量。
   ConstantInt* GetConstInt(int v);
-  // 生成临时名称，如 %t0、%t1 ...
+ 
   std::string NextTemp();
 
  private:

src/ir/IRBuilder.cpp

@@ -6,6 +6,13 @@
 #include <stdexcept>
 
 namespace ir {
+namespace {
+
+bool IsArithmeticType(const std::shared_ptr<Type>& ty) {
+  return ty && ty->kind() == Type::Kind::Int32;
+}
+
+}  // namespace
 
 ConstantInt* IRBuilder::CreateConstInt(int v) {
   // 常量不需要挂在基本块里，由 Context 负责去重与生命周期。
@@ -17,7 +24,23 @@ BinaryInst* IRBuilder::CreateBinary(Opcode op, Value* lhs, Value* rhs,
   if (!insertBlock_) {
     throw std::runtime_error("IRBuilder 未设置插入点");
   }
-  return insertBlock_->Append<BinaryInst>(op, Type::Int32(), lhs, rhs, name);
+  if (!lhs) {
+    throw std::runtime_error("IRBuilder::CreateBinary 缺少 lhs");
+  }
+  if (!rhs) {
+    throw std::runtime_error("IRBuilder::CreateBinary 缺少 rhs");
+  }
+  if (op != Opcode::Add) {
+    throw std::runtime_error("IRBuilder::CreateBinary 当前只支持 Add");
+  }
+  if (!lhs->type() || !rhs->type() ||
+      lhs->type()->kind() != rhs->type()->kind()) {
+    throw std::runtime_error("IRBuilder::CreateBinary 操作数类型不匹配");
+  }
+  if (!IsArithmeticType(lhs->type())) {
+    throw std::runtime_error("IRBuilder::CreateBinary 当前只支持 i32 二元运算");
+  }
+  return insertBlock_->Append<BinaryInst>(op, lhs->type(), lhs, rhs, name);
 }
 
 AllocaInst* IRBuilder::CreateAllocaI32(const std::string& name) {