81 lines
2.0 KiB
Java
81 lines
2.0 KiB
Java
/*******************************************************************************
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* Copyright (c) 2013 IBM Corporation.
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* All rights reserved. This program and the accompanying materials
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* are made available under the terms of the Eclipse Public License v1.0
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* which accompanies this distribution, and is available at
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* http://www.eclipse.org/legal/epl-v10.html
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*
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* Contributors:
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* IBM Corporation - initial API and implementation
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*******************************************************************************/
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package com.ibm.wala.cast.js.ssa;
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import java.util.Collection;
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import java.util.Collections;
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import com.ibm.wala.cast.js.types.JavaScriptTypes;
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import com.ibm.wala.ssa.SSAInstruction;
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import com.ibm.wala.ssa.SSAInstructionFactory;
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import com.ibm.wala.ssa.SymbolTable;
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import com.ibm.wala.types.TypeReference;
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/**
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* Checks if a reference is null or undefined, and if so, throws a
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* ReferenceError. Otherwise, it's a no-op.
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*/
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public class JavaScriptCheckReference extends SSAInstruction {
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private final int ref;
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public JavaScriptCheckReference(int iindex, int ref) {
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super(iindex);
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this.ref = ref;
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}
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@Override
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public SSAInstruction copyForSSA(SSAInstructionFactory insts, int[] defs, int[] uses) {
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return ((JSInstructionFactory)insts).CheckReference(iindex, uses==null? ref: uses[0]);
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}
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@Override
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public Collection<TypeReference> getExceptionTypes() {
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return Collections.singleton(JavaScriptTypes.ReferenceError);
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}
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@Override
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public int hashCode() {
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return 87621 * ref;
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}
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@Override
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public boolean isFallThrough() {
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return true;
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}
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@Override
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public String toString(SymbolTable symbolTable) {
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return "check " + getValueString(symbolTable, ref);
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}
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@Override
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public void visit(IVisitor v) {
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((JSInstructionVisitor)v).visitCheckRef(this);
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}
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@Override
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public boolean isPEI() {
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return true;
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}
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@Override
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public int getNumberOfUses() {
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return 1;
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}
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@Override
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public int getUse(int i) {
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assert i == 0;
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return ref;
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}
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}
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