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

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

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/*
 * Copyright 2007 Johannes Rieken
 * 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.AllowUnusedImport;
import com.google.java.contract.Invariant;
import com.google.java.contract.core.model.ClassName;
import com.google.java.contract.core.model.ContractKind;
import com.google.java.contract.core.util.DebugUtils;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.MethodNode;

import java.util.ArrayList;
import java.util.List;

/**
 * Bytecode class visitor. Initiates/delegates method instrumentation
 * to instances of {@link SpecificationMethodAdapter}.
 *
 * @author nhat.minh.le@huoc.org (Nhat Minh L)
 * @author johannes.rieken@gmail.com (Johannes Rieken)
 */
@AllowUnusedImport(ClassName.class)
@Invariant({ "getClassName() == null || ClassName.isBinaryName(getClassName())", "getContracts() != null",
        "getParent() != null" })
class SpecificationClassAdapter extends ClassVisitor {
    protected String className;
    protected ContractAnalyzer contracts;

    public SpecificationClassAdapter(ClassVisitor cv, ContractAnalyzer contracts) {
        super(Opcodes.ASM5, cv);
        this.contracts = contracts;
    }

    @Override
    public void visit(int version, int access, String name, String signature, String superName,
            String[] interfaces) {
        super.visit(version, access, name, signature, superName, interfaces);
        className = name;
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
        MethodVisitor mv = cv.visitMethod(access, name, desc, signature, exceptions);
        if ((access & (Opcodes.ACC_ABSTRACT | Opcodes.ACC_NATIVE)) != 0) {
            return mv;
        }

        return new SpecificationMethodAdapter(this, mv, access, name, desc);
    }

    @Override
    public void visitEnd() {
        if (contracts != null) {
            List<ClassContractHandle> synths = new ArrayList<ClassContractHandle>();
            synths.addAll(contracts.getClassHandles(ContractKind.ACCESS));
            synths.addAll(contracts.getClassHandles(ContractKind.LAMBDA));
            for (ClassContractHandle h : synths) {
                h.getContractMethod().accept(cv);
            }

            List<ClassContractHandle> helpers = contracts.getClassHandles(ContractKind.HELPER);
            for (ClassContractHandle h : helpers) {
                MethodNode methodNode = h.getContractMethod();
                DebugUtils.info("instrument",
                        "helper method " + className + "." + methodNode.name + methodNode.desc);
                ClassVisitor visitor = cv;
                List<Long> lineNumbers = h.getLineNumbers();
                if (lineNumbers != null) {
                    visitor = new LineNumberingClassAdapter(visitor, lineNumbers);
                }
                methodNode.accept(new ContractFixingClassAdapter(visitor));
                h.setInjected(true);
            }
        }
        super.visitEnd();
    }

    /**
     * Returns the name of the visited class.
     */
    String getClassName() {
        return className;
    }

    /**
     * Returns the class visitor this one delegates to.
     */
    ClassVisitor getParent() {
        return cv;
    }

    /**
     * Returns the contract analyzer of the visited class.
     */
    ContractAnalyzer getContracts() {
        return contracts;
    }
}