/******************************************************************************
* Copyright (c) 2002 - 2012 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*****************************************************************************/
package com.ibm.wala.cast.js.callgraph.fieldbased;
import com.ibm.wala.cast.ir.ssa.AstGlobalRead;
import com.ibm.wala.cast.js.ssa.JSAbstractInstructionVisitor;
import com.ibm.wala.cast.js.ssa.JavaScriptInvoke;
import com.ibm.wala.cast.js.types.JavaScriptMethods;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.ssa.DefUse;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SymbolTable;
/**
* A {@link JSAbstractInstructionVisitor} that is used to only visit instructions of a single method.
*
* @author mschaefer
*
*/
public class JSMethodInstructionVisitor extends JSAbstractInstructionVisitor {
protected final IMethod method;
protected final SymbolTable symtab;
protected final DefUse du;
public JSMethodInstructionVisitor(IMethod method, SymbolTable symtab, DefUse du) {
this.method = method;
this.symtab = symtab;
this.du = du;
}
/**
* Determine whether <code>invk</code> corresponds to a function declaration or function expression.
*
* TODO: A bit hackish. Is there a more principled way to do this?
*/
protected boolean isFunctionConstructorInvoke(JavaScriptInvoke invk) {
/*
* Function objects are allocated by explicit constructor invocations like this:
*
* v8 = global:global Function
* v4 = construct v8@2 v6:#L<fullFunctionName> exception:<nd>
*/
if(invk.getDeclaredTarget().equals(JavaScriptMethods.ctorReference)) {
int fn = invk.getFunction();
SSAInstruction fndef = du.getDef(fn);
if(fndef instanceof AstGlobalRead) {
AstGlobalRead agr = (AstGlobalRead)fndef;
if(agr.getGlobalName().equals("global Function")) {
if(invk.getNumberOfParameters() != 2)
return false;
// this may be a genuine use of "new Function()", not a declaration/expression
if(!symtab.isStringConstant(invk.getUse(1)))
return false;
return true;
}
}
}
return false;
}
}