org.eclipse.golo.compiler.JavaBytecodeUtils.java Source code

Introduction

Here is the source code for org.eclipse.golo.compiler.JavaBytecodeUtils.java

Source

/*
 * Copyright (c) 2012-2018 Institut National des Sciences Appliques de Lyon (INSA Lyon) and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 */

package org.eclipse.golo.compiler;

import gololang.ir.GoloElement;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;

import static org.objectweb.asm.Opcodes.*;

final class JavaBytecodeUtils {

    private JavaBytecodeUtils() {
        // utility class
    }

    static boolean between(int value, int lower, int upper) {
        return (value >= lower) && (value <= upper);
    }

    private static final int[] ICONST = { ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5 };

    static void loadInteger(MethodVisitor methodVisitor, int value) {
        if (between(value, Short.MIN_VALUE, Short.MAX_VALUE)) {
            if (between(value, Byte.MIN_VALUE, Byte.MAX_VALUE)) {
                if (between(value, -1, 5)) {
                    methodVisitor.visitInsn(ICONST[value + 1]);
                } else {
                    methodVisitor.visitIntInsn(BIPUSH, value);
                }
            } else {
                methodVisitor.visitIntInsn(SIPUSH, value);
            }
        } else {
            methodVisitor.visitLdcInsn(value);
        }
    }

    static void loadLong(MethodVisitor methodVisitor, long value) {
        if (value == 0) {
            methodVisitor.visitInsn(LCONST_0);
        } else if (value == 1) {
            methodVisitor.visitInsn(LCONST_1);
        } else {
            methodVisitor.visitLdcInsn(value);
        }
    }

    static Label visitLine(GoloElement<?> element, MethodVisitor visitor) {
        Label label = new Label();
        visitor.visitLabel(label);
        if (element.hasPosition()) {
            visitor.visitLineNumber(element.positionInSourceCode().getStartLine(), label);
        }
        return label;
    }
}