/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Rhino code, released
* May 6, 1999.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1997-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Norris Boyd
* Roger Lawrence
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License Version 2 or later (the "GPL"), in which
* case the provisions of the GPL are applicable instead of those above. If
* you wish to allow use of your version of this file only under the terms of
* the GPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replacing
* them with the notice and other provisions required by the GPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.javascript.optimizer;
import org.mozilla.javascript.*;
import java.util.Hashtable;
/**
* This class performs node transforms to prepare for optimization.
*
* @see NodeTransformer
* @author Norris Boyd
*/
class OptTransformer extends NodeTransformer {
OptTransformer(Hashtable possibleDirectCalls, ObjArray directCallTargets)
{
this.possibleDirectCalls = possibleDirectCalls;
this.directCallTargets = directCallTargets;
}
protected void visitNew(Node node, ScriptOrFnNode tree) {
detectDirectCall(node, tree);
super.visitNew(node, tree);
}
protected void visitCall(Node node, ScriptOrFnNode tree) {
detectDirectCall(node, tree);
super.visitCall(node, tree);
}
private void detectDirectCall(Node node, ScriptOrFnNode tree)
{
if (tree.getType() == Token.FUNCTION) {
Node left = node.getFirstChild();
// count the arguments
int argCount = 0;
Node arg = left.getNext();
while (arg != null) {
arg = arg.getNext();
argCount++;
}
if (argCount == 0) {
OptFunctionNode.get(tree).itsContainsCalls0 = true;
}
/*
* Optimize a call site by converting call("a", b, c) into :
*
* FunctionObjectFor"a" <-- instance variable init'd by constructor
*
* // this is a DIRECTCALL node
* fn = GetProp(tmp = GetBase("a"), "a");
* if (fn == FunctionObjectFor"a")
* fn.call(tmp, b, c)
* else
* ScriptRuntime.Call(fn, tmp, b, c)
*/
if (possibleDirectCalls != null) {
String targetName = null;
if (left.getType() == Token.NAME) {
targetName = left.getString();
} else if (left.getType() == Token.GETPROP) {
targetName = left.getFirstChild().getNext().getString();
} else if (left.getType() == Token.GETPROPNOWARN) {
throw Kit.codeBug();
}
if (targetName != null) {
OptFunctionNode ofn;
ofn = (OptFunctionNode)possibleDirectCalls.get(targetName);
if (ofn != null
&& argCount == ofn.fnode.getParamCount()
&& !ofn.fnode.requiresActivation())
{
// Refuse to directCall any function with more
// than 32 parameters - prevent code explosion
// for wacky test cases
if (argCount <= 32) {
node.putProp(Node.DIRECTCALL_PROP, ofn);
if (!ofn.isTargetOfDirectCall()) {
int index = directCallTargets.size();
directCallTargets.add(ofn);
ofn.setDirectTargetIndex(index);
}
}
}
}
}
}
}
private Hashtable possibleDirectCalls;
private ObjArray directCallTargets;
}
