build(antlr): 引入第三方 ANTLR4 runtime/tool 并接入构建

third_party/antlr4-runtime-4.13.2/runtime/src/ANTLRFileStream.cpp

@@ -0,0 +1,23 @@
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#include "ANTLRFileStream.h"
+
+using namespace antlr4;
+
+void ANTLRFileStream::loadFromFile(const std::string &fileName) {
+  _fileName = fileName;
+  if (_fileName.empty()) {
+    return;
+  }
+
+  std::ifstream stream(fileName, std::ios::binary);
+
+  ANTLRInputStream::load(stream);
+}
+
+std::string ANTLRFileStream::getSourceName() const {
+  return _fileName;
+}