Initial commit from sysy-main

antlr/antlr4-runtime-4.12.0/runtime/src/tree/ParseTreeWalker.cpp

@@ -0,0 +1,48 @@
+/* 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 "tree/ErrorNode.h"
+#include "ParserRuleContext.h"
+#include "tree/ParseTreeListener.h"
+#include "support/CPPUtils.h"
+#include "support/Casts.h"
+
+#include "tree/IterativeParseTreeWalker.h"
+#include "tree/ParseTreeWalker.h"
+
+using namespace antlr4::tree;
+using namespace antlrcpp;
+
+static IterativeParseTreeWalker defaultWalker;
+ParseTreeWalker &ParseTreeWalker::DEFAULT = defaultWalker;
+
+void ParseTreeWalker::walk(ParseTreeListener *listener, ParseTree *t) const {
+  if (ErrorNode::is(*t)) {
+    listener->visitErrorNode(downCast<ErrorNode*>(t));
+    return;
+  }
+  if (TerminalNode::is(*t)) {
+    listener->visitTerminal(downCast<TerminalNode*>(t));
+    return;
+  }
+
+  enterRule(listener, t);
+  for (auto &child : t->children) {
+    walk(listener, child);
+  }
+  exitRule(listener, t);
+}
+
+void ParseTreeWalker::enterRule(ParseTreeListener *listener, ParseTree *r) const {
+  auto *ctx = downCast<ParserRuleContext*>(r);
+  listener->enterEveryRule(ctx);
+  ctx->enterRule(listener);
+}
+
+void ParseTreeWalker::exitRule(ParseTreeListener *listener, ParseTree *r) const {
+  auto *ctx = downCast<ParserRuleContext*>(r);
+  ctx->exitRule(listener);
+  listener->exitEveryRule(ctx);
+}