org.sonar.java.model.LiteralUtils.java Source code

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Here is the source code for org.sonar.java.model.LiteralUtils.java

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/*
 * SonarQube Java
 * Copyright (C) 2012-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.java.model;

import org.apache.commons.lang.StringUtils;
import org.sonar.plugins.java.api.tree.ExpressionTree;
import org.sonar.plugins.java.api.tree.LiteralTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.Tree.Kind;
import org.sonar.plugins.java.api.tree.UnaryExpressionTree;

import javax.annotation.CheckForNull;
import javax.annotation.Nullable;

public class LiteralUtils {

    private LiteralUtils() {
        // This class only contains static methods
    }

    @CheckForNull
    public static Integer intLiteralValue(ExpressionTree expression) {
        if (expression.is(Tree.Kind.INT_LITERAL)) {
            return intLiteralValue((LiteralTree) expression);
        }
        if (expression.is(Tree.Kind.UNARY_MINUS, Tree.Kind.UNARY_PLUS)) {
            UnaryExpressionTree unaryExp = (UnaryExpressionTree) expression;
            Integer subExpressionIntValue = intLiteralValue(unaryExp.expression());
            return expression.is(Tree.Kind.UNARY_MINUS) ? minus(subExpressionIntValue) : subExpressionIntValue;
        }
        return null;
    }

    @CheckForNull
    private static Integer intLiteralValue(LiteralTree literal) {
        String literalValue = literal.value().replaceAll("_", "");
        if (literalValue.startsWith("0x") || literalValue.startsWith("0b")) {
            return null;
        }
        return Integer.valueOf(literalValue);
    }

    @CheckForNull
    public static Long longLiteralValue(ExpressionTree tree) {
        ExpressionTree expression = tree;

        int sign = tree.is(Kind.UNARY_MINUS) ? -1 : 1;
        if (tree.is(Kind.UNARY_MINUS, Kind.UNARY_PLUS)) {
            expression = ((UnaryExpressionTree) tree).expression();
        }

        if (expression.is(Kind.INT_LITERAL, Kind.LONG_LITERAL)) {
            String value = trimLongSuffix(((LiteralTree) expression).value());
            // long as hexadecimal can be written using underscore to separate groups
            value = value.replaceAll("\\_", "");
            try {
                return sign * Long.decode(value);
            } catch (NumberFormatException e) {
                // Long.decode() may fail in case of very large long number written in hexadecimal. In such situation, we ignore the number.
                // Note that Long.MAX_VALUE = "0x7FFF_FFFF_FFFF_FFFFL", but it is possible to write larger numbers in hexadecimal
                // to be used as mask in bitwise operation. For instance:
                // 0x8000_0000_0000_0000L (MAX_VALUE + 1),
                // 0xFFFF_FFFF_FFFF_FFFFL (only ones),
                // 0xFFFF_FFFF_FFFF_FFFEL (only ones except least significant bit), ...
            }
        }
        return null;
    }

    @CheckForNull
    private static Integer minus(@Nullable Integer nullableInteger) {
        return nullableInteger == null ? null : -nullableInteger;
    }

    public static String trimQuotes(String value) {
        return value.substring(1, value.length() - 1);
    }

    public static String trimLongSuffix(String longString) {
        if (StringUtils.isBlank(longString)) {
            return longString;
        }
        int lastCharPosition = longString.length() - 1;
        char lastChar = longString.charAt(lastCharPosition);
        String value = longString;
        if (lastChar == 'L' || lastChar == 'l') {
            value = longString.substring(0, lastCharPosition);
        }
        return value;
    }
}