com.google.java.contract.core.agent.LineNumberingClassAdapter.java Source code

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Here is the source code for com.google.java.contract.core.agent.LineNumberingClassAdapter.java

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/*
 * Copyright 2010 Google Inc.
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */
package com.google.java.contract.core.agent;

import com.google.java.contract.Invariant;
import com.google.java.contract.Requires;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

import java.util.List;

/**
 * A class adapter that adds a line number to methods.
 *
 * @author nhat.minh.le@huoc.org (Nhat Minh L)
 */
@Invariant("ContractMethodSignatures.isLineNumberList(lineNumbers)")
class LineNumberingClassAdapter extends ClassVisitor {
    protected List<Long> lineNumbers;

    /**
     * Constructs a new LineNumberingClassAdapter.
     *
     * @param cv the ClassVisitor this adapter delegates to
     * @param lineNumbers the line numbers to associate with methods
     */
    @Requires({ "cv != null", "ContractMethodSignatures.isLineNumberList(lineNumbers)" })
    public LineNumberingClassAdapter(ClassVisitor cv, List<Long> lineNumbers) {
        super(Opcodes.ASM5, cv);
        this.lineNumbers = lineNumbers;
    }

    /**
     * Visits the specified method, adding line numbering.
     */
    @Override
    public MethodVisitor visitMethod(int access, final String name, String desc, String signature,
            String[] exceptions) {
        MethodVisitor mv = cv.visitMethod(access | Opcodes.ACC_SYNTHETIC, name, desc, signature, exceptions);
        return new LineNumberingMethodAdapter(mv, access | Opcodes.ACC_SYNTHETIC, name, desc) {
            @Override
            protected void onMethodEnter() {
                this.lineNumbers = LineNumberingClassAdapter.this.lineNumbers;
                super.onMethodEnter();
            }
        };
    }
}