com.google.javascript.jscomp.Es6RenameReferences Maven / Gradle / Ivy
/*
* Copyright 2015 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp;
import com.google.common.collect.Table;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.rhino.Node;
/** Renames references in code. */
final class Es6RenameReferences extends AbstractPostOrderCallback {
/**
* Map from the root node of a scope + the original variable name to a new name for the variable.
*
* An entry in this map means we should rename a variable that was originally declared in the
* scope with the given root and had the original variable name to the new name.
*/
private final Table renameTable;
Es6RenameReferences(Table renameTable) {
this.renameTable = renameTable;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (NodeUtil.isReferenceName(n)) {
renameReference(t, n, n.getString());
}
}
/**
* @param t The NodeTraversal.
* @param oldName The root name of a qualified name.
*/
private void renameReference(NodeTraversal t, Node n, String oldName) {
Scope current = t.getScope();
// You should be wondering:
//
// Why are we searching up the stack of scopes here instead of just looking up the Var for
// oldName and getting the scope from that?
//
// The answer is:
//
// When Es6RewriteBlockScopedDeclaration uses this class, it has already modified the scopes so
// that `oldName` is no longer declared in its original scope.
//
// I don't know if the other users of this class are also modifying the scopes in advance.
// - [email protected]
while (current != null) {
String newName = renameTable.get(current.getRootNode(), oldName);
if (newName != null) {
n.setString(newName);
t.reportCodeChange();
return;
} else if (current.hasOwnSlot(oldName)) {
return;
} else {
current = current.getParent();
}
}
}
}