/*
* Copyright 2008 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.Lists;
import com.google.common.collect.Maps;
import com.google.javascript.jscomp.NodeTraversal.Callback;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
/**
* Moves top level function declarations to the top.
*
* Enable this pass if a try catch block wraps the output after compilation,
* and the output runs on Firefox because function declarations are only
* defined when reached inside a try catch block on Firefox.
*
* On Firefox, this code works:
*
* var g = f;
* function f() {}
*
* but this code does not work:
*
* try {
* var g = f;
* function f() {}
* } catch(e) {}
*
*/
class MoveFunctionDeclarations implements Callback, CompilerPass {
private final AbstractCompiler compiler;
private final Map<JSModule, List<Node>> functions;
MoveFunctionDeclarations(AbstractCompiler compiler) {
this.compiler = compiler;
functions = Maps.newHashMap();
}
@Override
public void process(Node externs, Node root) {
NodeTraversal.traverse(compiler, root, this);
for (Entry<JSModule, List<Node>> entry : functions.entrySet()) {
JSModule module = entry.getKey();
Node addingRoot = compiler.getNodeForCodeInsertion(module);
for (Node n : Lists.reverse(entry.getValue())) {
addingRoot.addChildToFront(n);
}
}
}
@Override
public boolean shouldTraverse(NodeTraversal t, Node n, Node parent) {
Node gramps = n.getAncestor(2);
return gramps == null || gramps.getType() != Token.SCRIPT;
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (parent == null ||
parent.getType() != Token.SCRIPT) {
return;
}
if (NodeUtil.isFunctionDeclaration(n)) {
parent.removeChild(n);
compiler.reportCodeChange();
JSModule module = t.getModule();
List<Node> moduleFunctions = functions.get(module);
if (moduleFunctions == null) {
moduleFunctions = Lists.newArrayList();
functions.put(module, moduleFunctions);
}
moduleFunctions.add(n);
}
}
}