HandlerJoinPointCompiler.java

/**************************************************************************************
 * Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved.                 *
 * http://aspectwerkz.codehaus.org                                                    *
 * ---------------------------------------------------------------------------------- *
 * The software in this package is published under the terms of the LGPL license      *
 * a copy of which has been included with this distribution in the license.txt file.  *
 **************************************************************************************/
package org.codehaus.aspectwerkz.transform.inlining.compiler;

import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Type;

/**
 * A compiler that compiles/generates a class that represents a specific join point, a class which invokes the advices
 * and the target join point statically.
 * <p/>
 * In this case, CALLEE is the catched exception instance itself.
 *
 * @author <a href="mailto:jboner@codehaus.org">Jonas Bon�r </a>
 * @author <a href="mailto:alex AT gnilux DOT com">Alexandre Vasseur </a>
 */
public class HandlerJoinPointCompiler extends AbstractJoinPointCompiler {

    /**
     * Creates a new join point compiler instance.
     *
     * @param model
     */
    HandlerJoinPointCompiler(final CompilationInfo.Model model) {
        super(model);
    }

    /**
     * Creates join point specific fields.
     */
    protected void createJoinPointSpecificFields() {
        // create the field argument field
        String[] fieldNames = null;
        Type fieldType = Type.getType(m_calleeClassSignature);
        fieldNames = new String[1];
        String fieldName = ARGUMENT_FIELD + 0;
        fieldNames[0] = fieldName;
        m_cw.visitField(ACC_PRIVATE, fieldName, fieldType.getDescriptor(), null, null);
        m_fieldNames = fieldNames;
        m_cw.visitField(
                ACC_PRIVATE + ACC_STATIC,
                SIGNATURE_FIELD_NAME,
                HANDLER_SIGNATURE_IMPL_CLASS_SIGNATURE,
                null,
                null
        );
    }

    /**
     * Creates the signature for the join point.
     *
     * @param cv
     */
    protected void createSignature(final MethodVisitor cv) {
        cv.visitFieldInsn(GETSTATIC, m_joinPointClassName, TARGET_CLASS_FIELD_NAME_IN_JP, CLASS_CLASS_SIGNATURE);

        cv.visitMethodInsn(
                INVOKESTATIC,
                SIGNATURE_FACTORY_CLASS,
                NEW_CATCH_CLAUSE_SIGNATURE_METHOD_NAME,
                NEW_HANDLER_SIGNATURE_METHOD_SIGNATURE
        );
        cv.visitFieldInsn(
                PUTSTATIC, m_joinPointClassName, SIGNATURE_FIELD_NAME, HANDLER_SIGNATURE_IMPL_CLASS_SIGNATURE
        );

    }

    /**
     * Optimized implementation that does not retrieve the parameters from the join point instance but is passed
     * directly to the method from the input parameters in the 'invoke' method. Can only be used if no around advice
     * exists.
     *
     * @param cv
     * @param input
     */
    protected void createInlinedJoinPointInvocation(final MethodVisitor cv,
                                                    final CompilerInput input) {
        // load the exception
        cv.visitVarInsn(ALOAD, 0);//TODO if changed perhaps load CALLEE instead that host the exception ?
    }

    /**
     * Creates a call to the target join point, the parameter(s) to the join point are retrieved from the invocation
     * local join point instance.
     *
     * @param cv
     */
    protected void createJoinPointInvocation(final MethodVisitor cv) {
        cv.visitInsn(ACONST_NULL);
    }

    /**
     * Returns the join points return type.
     *
     * @return
     */
    protected Type getJoinPointReturnType() {
        return Type.getType(m_calleeClassSignature);
    }

    /**
     * Returns the join points argument type(s).
     *
     * @return
     */
    protected Type[] getJoinPointArgumentTypes() {
        return new Type[]{Type.getType(m_calleeClassSignature)};//TODO should callee be arg instead ? to bind it later ?
    }

    /**
     * Creates the getRtti method
     */
    protected void createGetRttiMethod() {
        MethodVisitor cv = m_cw.visitMethod(ACC_PUBLIC, GET_RTTI_METHOD_NAME, GET_RTTI_METHOD_SIGNATURE, null, null);

        // new CtorRttiImpl( .. )
        cv.visitTypeInsn(NEW, HANDLER_RTTI_IMPL_CLASS_NAME);
        cv.visitInsn(DUP);
        cv.visitFieldInsn(
                GETSTATIC, m_joinPointClassName, SIGNATURE_FIELD_NAME, HANDLER_SIGNATURE_IMPL_CLASS_SIGNATURE
        );
        cv.visitVarInsn(ALOAD, 0);
        cv.visitFieldInsn(GETFIELD, m_joinPointClassName, CALLER_INSTANCE_FIELD_NAME, m_callerClassSignature);
        cv.visitVarInsn(ALOAD, 0);
        cv.visitFieldInsn(GETFIELD, m_joinPointClassName, CALLEE_INSTANCE_FIELD_NAME, m_calleeClassSignature);
        cv.visitMethodInsn(
                INVOKESPECIAL, HANDLER_RTTI_IMPL_CLASS_NAME, INIT_METHOD_NAME, HANDLER_RTTI_IMPL_INIT_SIGNATURE
        );

        cv.visitInsn(ARETURN);
        cv.visitMaxs(0, 0);
    }

    /**
     * Creates the getSignature method.
     */
    protected void createGetSignatureMethod() {
        MethodVisitor cv = m_cw.visitMethod(
                ACC_PUBLIC,
                GET_SIGNATURE_METHOD_NAME,
                GET_SIGNATURE_METHOD_SIGNATURE,
                null,
                null
        );
        cv.visitFieldInsn(
                GETSTATIC, m_joinPointClassName,
                SIGNATURE_FIELD_NAME, HANDLER_SIGNATURE_IMPL_CLASS_SIGNATURE
        );
        cv.visitInsn(ARETURN);
        cv.visitMaxs(0, 0);
    }
}