/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * 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 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.*;
import org.eclipse.jdt.internal.compiler.parser.ScannerHelper;

public class LongLiteral extends NumberLiteral {
	long value;
	
	static final Constant FORMAT_ERROR = DoubleConstant.fromValue(1.0/0.0); // NaN;	
		
public LongLiteral(char[] token, int s,int e) {
	super(token, s,e);
}
public LongLiteral(char[] token, int s,int e, long value) {
	this(token, s,e);
	this.value = value;
}
public void computeConstant() {
	//the overflow (when radix=10) is tested using the fact that
	//the value should always grow during its computation
	int length = source.length - 1; //minus one because the last char is 'l' or 'L'
	
	long computedValue ;
	if (source[0] == '0') {
		if (length == 1) {
			constant = LongConstant.fromValue(0L);
			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;
		}
		int nbDigit = 0;
		while (source[j]=='0') {
			j++; //jump over redondant zero
			if ( j == length) {
				//watch for 0000000000000L
				constant = LongConstant.fromValue(value = 0L);
				return ;
			}
		}
				
		int digitValue ;
		if ((digitValue = ScannerHelper.digit(source[j++],radix)) < 0 ) {
			constant = FORMAT_ERROR; return ;
		}
		if (digitValue >= 8)
			nbDigit = 4;
		else if (digitValue >= 4)
			nbDigit = 3;
		else if (digitValue >= 2)
			nbDigit = 2;
		else
			nbDigit = 1; //digitValue is not 0
		computedValue = digitValue ;
		while (j<length) {
			if ((digitValue = ScannerHelper.digit(source[j++],radix)) < 0) {
				constant = FORMAT_ERROR; return ;
			}
			if ((nbDigit += shift) > 64)
				return /*constant stays null*/ ;
			computedValue = (computedValue<<shift) | digitValue ;
		}
	} else {
		//-----------case radix=10-----------------
		long previous = 0;
		computedValue = 0;
		final long limit = Long.MAX_VALUE / 10; // needed to check prior to the multiplication
		for (int i = 0 ; i < length; i++) {
			int digitValue ;	
			if ((digitValue = ScannerHelper.digit(source[i], 10)) < 0 ) return /*constant stays null*/;
			previous = computedValue;
			if (computedValue > limit)
				return /*constant stays null*/;
			computedValue *= 10;
			if ((computedValue + digitValue) > Long.MAX_VALUE)
				return /*constant stays null*/;
			computedValue += digitValue;
			if (previous > computedValue)
				return /*constant stays null*/;
		}
	}
	constant = LongConstant.fromValue(value = computedValue);
}
/**
 * Code generation for long 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) {
		codeStream.generateConstant(constant, implicitConversion);
	}
	codeStream.recordPositionsFrom(pc, this.sourceStart);
}
public TypeBinding literalType(BlockScope scope) {
	return TypeBinding.LONG;
}
public final boolean mayRepresentMIN_VALUE(){
	//a special autorized int literral is 9223372036854775808L
	//which is ONE over the limit. This special case 
	//only is used in combinaison with - to denote
	//the minimal value of int -9223372036854775808L

	return ((source.length == 20) &&
			(source[0] == '9') &&
			(source[1] == '2') &&
			(source[2] == '2') &&
			(source[3] == '3') &&			
			(source[4] == '3') &&
			(source[5] == '7') &&
			(source[6] == '2') &&
			(source[7] == '0') &&			
			(source[8] == '3') &&
			(source[9] == '6') &&
			(source[10] == '8') &&
			(source[11] == '5') &&
			(source[12] == '4') &&			
			(source[13] == '7') &&
			(source[14] == '7') &&
			(source[15] == '5') &&
			(source[16] == '8') &&			
			(source[17] == '0') &&
			(source[18] == '8') &&
			(((this.bits & ASTNode.ParenthesizedMASK) >> ASTNode.ParenthesizedSHIFT) == 0));
}
public TypeBinding resolveType(BlockScope scope) {
	// the format may be incorrect while the scanner could detect
	// such error only on painfull tests...easier and faster here

	TypeBinding tb = super.resolveType(scope);
	if (constant == FORMAT_ERROR) {
		constant = Constant.NotAConstant;
		scope.problemReporter().constantOutOfFormat(this);
		this.resolvedType = null;
		return null;
	}
	return tb;
}
public void traverse(ASTVisitor visitor, BlockScope scope) {
	visitor.visit(this, scope);
	visitor.endVisit(this, scope);
}
}
