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* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package jdk.nashorn.internal.ir;
import static jdk.nashorn.internal.parser.TokenType.BIT_NOT;
import static jdk.nashorn.internal.parser.TokenType.DECPOSTFIX;
import static jdk.nashorn.internal.parser.TokenType.INCPOSTFIX;
import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import jdk.nashorn.internal.codegen.types.Type;
import jdk.nashorn.internal.ir.annotations.Ignore;
import jdk.nashorn.internal.ir.annotations.Immutable;
import jdk.nashorn.internal.ir.visitor.NodeVisitor;
import jdk.nashorn.internal.parser.Token;
import jdk.nashorn.internal.parser.TokenType;
/**
* UnaryNode nodes represent single operand operations.
*/
@Immutable
public final class UnaryNode extends Expression implements Assignment<Expression>, Optimistic {
private static final long serialVersionUID = 1L;
/** Right hand side argument. */
private final Expression expression;
private final int programPoint;
private final Type type;
@Ignore
private static final List<TokenType> CAN_OVERFLOW =
Collections.unmodifiableList(
Arrays.asList(new TokenType[] {
TokenType.ADD,
TokenType.SUB, //negate
TokenType.DECPREFIX,
TokenType.DECPOSTFIX,
TokenType.INCPREFIX,
TokenType.INCPOSTFIX,
}));
/**
* Constructor
*
* @param token token
* @param rhs expression
*/
public UnaryNode(final long token, final Expression rhs) {
this(token, Math.min(rhs.getStart(), Token.descPosition(token)), Math.max(Token.descPosition(token) + Token.descLength(token), rhs.getFinish()), rhs);
}
/**
* Constructor
*
* @param token token
* @param start start
* @param finish finish
* @param expression expression
*/
public UnaryNode(final long token, final int start, final int finish, final Expression expression) {
super(token, start, finish);
this.expression = expression;
this.programPoint = INVALID_PROGRAM_POINT;
this.type = null;
}
private UnaryNode(final UnaryNode unaryNode, final Expression expression, final Type type, final int programPoint) {
super(unaryNode);
this.expression = expression;
this.programPoint = programPoint;
this.type = type;
}
/**
* Is this an assignment - i.e. that mutates something such as a++
*
* @return true if assignment
*/
@Override
public boolean isAssignment() {
switch (tokenType()) {
case DECPOSTFIX:
case DECPREFIX:
case INCPOSTFIX:
case INCPREFIX:
return true;
default:
return false;
}
}
@Override
public boolean isSelfModifying() {
return isAssignment();
}
@Override
public Type getWidestOperationType() {
switch (tokenType()) {
case ADD:
final Type operandType = getExpression().getType();
if(operandType == Type.BOOLEAN) {
return Type.INT;
} else if(operandType.isObject()) {
return Type.NUMBER;
}
assert operandType.isNumeric();
return operandType;
case SUB:
// This might seems overly conservative until you consider that -0 can only be represented as a double.
return Type.NUMBER;
case NOT:
case DELETE:
return Type.BOOLEAN;
case BIT_NOT:
return Type.INT;
case VOID:
return Type.UNDEFINED;
default:
return isAssignment() ? Type.NUMBER : Type.OBJECT;
}
}
@Override
public Expression getAssignmentDest() {
return isAssignment() ? getExpression() : null;
}
@Override
public UnaryNode setAssignmentDest(final Expression n) {
return setExpression(n);
}
@Override
public Expression getAssignmentSource() {
return getAssignmentDest();
}
/**
* Assist in IR navigation.
* @param visitor IR navigating visitor.
*/
@Override
public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
if (visitor.enterUnaryNode(this)) {
return visitor.leaveUnaryNode(setExpression((Expression)expression.accept(visitor)));
}
return this;
}
@Override
public boolean isLocal() {
switch (tokenType()) {
case NEW:
return false;
case ADD:
case SUB:
case NOT:
case BIT_NOT:
return expression.isLocal() && expression.getType().isJSPrimitive();
case DECPOSTFIX:
case DECPREFIX:
case INCPOSTFIX:
case INCPREFIX:
return expression instanceof IdentNode && expression.isLocal() && expression.getType().isJSPrimitive();
default:
return expression.isLocal();
}
}
@Override
public void toString(final StringBuilder sb, final boolean printType) {
toString(sb,
new Runnable() {
@Override
public void run() {
getExpression().toString(sb, printType);
}
},
printType);
}
/**
* Creates the string representation of this unary node, delegating the creation of the string representation of its
* operand to a specified runnable.
* @param sb the string builder to use
* @param rhsStringBuilder the runnable that appends the string representation of the operand to the string builder
* @param printType should we print type
* when invoked.
*/
public void toString(final StringBuilder sb, final Runnable rhsStringBuilder, final boolean printType) {
final TokenType tokenType = tokenType();
final String name = tokenType.getName();
final boolean isPostfix = tokenType == DECPOSTFIX || tokenType == INCPOSTFIX;
if (isOptimistic()) {
sb.append(Expression.OPT_IDENTIFIER);
}
boolean rhsParen = tokenType.needsParens(getExpression().tokenType(), false);
if (!isPostfix) {
if (name == null) {
sb.append(tokenType.name());
rhsParen = true;
} else {
sb.append(name);
if (tokenType.ordinal() > BIT_NOT.ordinal()) {
sb.append(' ');
}
}
}
if (rhsParen) {
sb.append('(');
}
rhsStringBuilder.run();
if (rhsParen) {
sb.append(')');
}
if (isPostfix) {
sb.append(tokenType == DECPOSTFIX ? "--" : "++");
}
}
/**
* Get the right hand side of this if it is inherited by a binary expression,
* or just the expression itself if still Unary
*
* @see BinaryNode
*
* @return right hand side or expression node
*/
public Expression getExpression() {
return expression;
}
/**
* Reset the right hand side of this if it is inherited by a binary expression,
* or just the expression itself if still Unary
*
* @see BinaryNode
*
* @param expression right hand side or expression node
* @return a node equivalent to this one except for the requested change.
*/
public UnaryNode setExpression(final Expression expression) {
if (this.expression == expression) {
return this;
}
return new UnaryNode(this, expression, type, programPoint);
}
@Override
public int getProgramPoint() {
return programPoint;
}
@Override
public UnaryNode setProgramPoint(final int programPoint) {
if (this.programPoint == programPoint) {
return this;
}
return new UnaryNode(this, expression, type, programPoint);
}
@Override
public boolean canBeOptimistic() {
return getMostOptimisticType() != getMostPessimisticType();
}
@Override
public Type getMostOptimisticType() {
if (CAN_OVERFLOW.contains(tokenType())) {
return Type.INT;
}
return getMostPessimisticType();
}
@Override
public Type getMostPessimisticType() {
return getWidestOperationType();
}
@Override
public Type getType() {
final Type widest = getWidestOperationType();
if(type == null) {
return widest;
}
return Type.narrowest(widest, Type.widest(type, expression.getType()));
}
@Override
public UnaryNode setType(final Type type) {
if (this.type == type) {
return this;
}
return new UnaryNode(this, expression, type, programPoint);
}
}