IntLiteral.java

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.impl.*;
import org.eclipse.jdt.internal.compiler.codegen.*;
import org.eclipse.jdt.internal.compiler.lookup.*;

public class IntLiteral extends NumberLiteral {
	public int value;
	
	public static final IntLiteral
		One = new IntLiteral(new char[]{'1'},0,0,1);//used for ++ and -- 

	static final Constant FORMAT_ERROR = new DoubleConstant(1.0/0.0); // NaN;
public IntLiteral(char[] token, int s, int e) {
	super(token, s,e);
}
public IntLiteral(char[] token, int s,int e, int value) {
	this(token, s,e);
	this.value = value;
}
public IntLiteral(int intValue) {
	//special optimized constructor : the cst is the argument 

	//value that should not be used
	//	tokens = null ;
	//	sourceStart = 0;
	//	sourceEnd = 0;
	super(null,0,0);
	constant = Constant.fromValue(intValue);
	value = intValue;
	
}
public void computeConstant() {
	//a special constant is use for the potential Integer.MAX_VALUE+1
	//which is legal if used with a - as prefix....cool....
	//notice that Integer.MIN_VALUE  == -2147483648

	long MAX = Integer.MAX_VALUE;
	if (this == One) {	constant = Constant.One; return ;}
	
	int length = source.length;
	long computedValue = 0L;
	if (source[0] == '0')
	{	MAX = 0xFFFFFFFFL ; //a long in order to be positive ! 	
		if (length == 1) {	constant = Constant.fromValue(0); return ;}
		final int shift,radix;
		int j ;
		if ( (source[1] == 'x') || (source[1] == 'X') )
		{	shift = 4 ; j = 2; radix = 16;}
		else
		{	shift = 3 ; j = 1; radix = 8;}
		while (source[j]=='0') 
		{	j++; //jump over redondant zero
			if (j == length)
			{	//watch for 000000000000000000
				constant = Constant.fromValue(value = (int)computedValue);
				return ;}}
		
		while (j<length)
		{	int digitValue ;
			if ((digitValue = Character.digit(source[j++],radix))	< 0 ) 	
			{	constant = FORMAT_ERROR; return ;}
			computedValue = (computedValue<<shift) | digitValue ;
			if (computedValue > MAX) return /*constant stays null*/ ;}}
	else
	{	//-----------regular case : radix = 10-----------
		for (int i = 0 ; i < length;i++)
		{	int digitValue ;
			if ((digitValue = Character.digit(source[i],10))	< 0 ) 
			{	constant = FORMAT_ERROR; return ;}
			computedValue = 10*computedValue + digitValue;
			if (computedValue > MAX) return /*constant stays null*/ ; }}

	constant = Constant.fromValue(value = (int)computedValue);
		
}
/**
 * Code generation for int literal
 *
 * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
 * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
 * @param valueRequired boolean
 */ 
public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
	int pc = codeStream.position;
	if (valueRequired)
		if ((implicitConversion >> 4) == T_int)
			codeStream.generateInlinedValue(value);
		else
			codeStream.generateConstant(constant, implicitConversion);
	codeStream.recordPositionsFrom(pc, this.sourceStart);
}
public TypeBinding literalType(BlockScope scope) {
	return IntBinding;
}
public final boolean mayRepresentMIN_VALUE(){
	//a special autorized int literral is 2147483648
	//which is ONE over the limit. This special case 
	//only is used in combinaison with - to denote
	//the minimal value of int -2147483648

	return ((source.length == 10) &&
			(source[0] == '2') &&
			(source[1] == '1') &&
			(source[2] == '4') &&
			(source[3] == '7') &&			
			(source[4] == '4') &&
			(source[5] == '8') &&
			(source[6] == '3') &&
			(source[7] == '6') &&			
			(source[8] == '4') &&
			(source[9] == '8'));}
public TypeBinding resolveType(BlockScope scope) {
	// the format may be incorrect while the scanner could detect
	// such an error only on painfull tests...easier and faster here

	TypeBinding tb = super.resolveType(scope);
	if (constant == FORMAT_ERROR) {
		constant = NotAConstant;
		scope.problemReporter().constantOutOfFormat(this);
		this.resolvedType = null;
		return null;
	}
	return tb;
}
public StringBuffer printExpression(int indent, StringBuffer output){

	if (source == null) {
	/* special optimized IntLiteral that are created by the compiler */
		return output.append(String.valueOf(value));
	}
	return super.printExpression(indent, output);
}
	
public void traverse(ASTVisitor visitor, BlockScope scope) {
	visitor.visit(this, scope);
	visitor.endVisit(this, scope);
}
}