fix(frontend): 补充不支持语法的警告输出

src/frontend/AntlrDriver.cpp

@@ -4,15 +4,30 @@
 #include <fstream>
 #include <sstream>
 #include <stdexcept>
+#include <string>
 
 #include "SysYLexer.h"
 #include "SysYParser.h"
 #include "antlr4-runtime.h"
 
+namespace {
+
+class ParseErrorListener : public antlr4::BaseErrorListener {
+ public:
+  void syntaxError(antlr4::Recognizer* /*recognizer*/, antlr4::Token* /*offendingSymbol*/,
+                   size_t line, size_t charPositionInLine,
+                   const std::string& msg, std::exception_ptr /*e*/) override {
+    throw std::runtime_error("[parse] 暂不支持的语法/词法 @" + std::to_string(line) + ":" +
+                             std::to_string(charPositionInLine) + " - " + msg);
+  }
+};
+
+}  // namespace
+
 AntlrResult ParseFileWithAntlr(const std::string& path) {
   std::ifstream fin(path);
   if (!fin.is_open()) {
-    throw std::runtime_error("无法打开输入文件: " + path);
+    throw std::runtime_error("[parse] 无法打开输入文件: " + path);
   }
   std::ostringstream ss;
   ss << fin.rdbuf();
@@ -21,8 +36,29 @@ AntlrResult ParseFileWithAntlr(const std::string& path) {
   auto lexer = std::make_unique<SysYLexer>(input.get());
   auto tokens = std::make_unique<antlr4::CommonTokenStream>(lexer.get());
   auto parser = std::make_unique<SysYParser>(tokens.get());
+
+  ParseErrorListener error_listener;
+  lexer->removeErrorListeners();
+  lexer->addErrorListener(&error_listener);
   parser->removeErrorListeners();
-  auto tree = parser->compUnit();
+  parser->addErrorListener(&error_listener);
+  parser->setErrorHandler(std::make_shared<antlr4::BailErrorStrategy>());
+  antlr4::tree::ParseTree* tree = nullptr;
+  try {
+    tree = parser->compUnit();
+  } catch (const std::exception& ex) {
+    const std::string msg = ex.what();
+    if (!msg.empty()) {
+      throw std::runtime_error("[parse] 暂不支持的语法/词法 - " + msg);
+    }
+    if (auto* tok = parser->getCurrentToken()) {
+      throw std::runtime_error("[parse] 暂不支持的语法/词法 @" +
+                               std::to_string(tok->getLine()) + ":" +
+                               std::to_string(tok->getCharPositionInLine()) +
+                               " near token '" + tok->getText() + "'");
+    }
+    throw std::runtime_error("[parse] 暂不支持的语法/词法");
+  }
 
   AntlrResult result;
   result.input = std::move(input);