Java Bytecode.addOpcode方法代码示例

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
/**
 * Declares a constructor that takes no parameter.
 *
 * @param classfile The class descriptor
 *
 * @throws CannotCompileException Indicates trouble with the underlying Javassist calls
 */
private void addDefaultConstructor(ClassFile classfile) throws CannotCompileException {
	final ConstPool constPool = classfile.getConstPool();
	final String constructorSignature = "()V";
	final MethodInfo constructorMethodInfo = new MethodInfo( constPool, MethodInfo.nameInit, constructorSignature );

	final Bytecode code = new Bytecode( constPool, 0, 1 );
	// aload_0
	code.addAload( 0 );
	// invokespecial
	code.addInvokespecial( BulkAccessor.class.getName(), MethodInfo.nameInit, constructorSignature );
	// return
	code.addOpcode( Opcode.RETURN );

	constructorMethodInfo.setCodeAttribute( code.toCodeAttribute() );
	constructorMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
	classfile.addMethod( constructorMethodInfo );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
/**
 * Declares a constructor that takes no parameter.
 *
 * @param classfile
 * @throws CannotCompileException
 */
private void addDefaultConstructor(ClassFile classfile) throws CannotCompileException {
	ConstPool cp = classfile.getConstPool();
	String cons_desc = "()V";
	MethodInfo mi = new MethodInfo( cp, MethodInfo.nameInit, cons_desc );

	Bytecode code = new Bytecode( cp, 0, 1 );
	// aload_0
	code.addAload( 0 );
	// invokespecial
	code.addInvokespecial( BulkAccessor.class.getName(), MethodInfo.nameInit, cons_desc );
	// return
	code.addOpcode( Opcode.RETURN );

	mi.setCodeAttribute( code.toCodeAttribute() );
	mi.setAccessFlags( AccessFlag.PUBLIC );
	classfile.addMethod( mi );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addGetFieldHandlerMethod(ClassFile classfile)
		throws CannotCompileException {
	ConstPool cp = classfile.getConstPool();
	int this_class_index = cp.getThisClassInfo();
	MethodInfo minfo = new MethodInfo(cp, GETFIELDHANDLER_METHOD_NAME,
	                                  GETFIELDHANDLER_METHOD_DESCRIPTOR);
	/* local variable | this | */
	Bytecode code = new Bytecode(cp, 2, 1);
	// aload_0 // load this
	code.addAload(0);
	// getfield // get field "$JAVASSIST_CALLBACK" defined already
	code.addOpcode(Opcode.GETFIELD);
	int field_index = cp.addFieldrefInfo(this_class_index,
	                                     HANDLER_FIELD_NAME, HANDLER_FIELD_DESCRIPTOR);
	code.addIndex(field_index);
	// areturn // return the value of the field
	code.addOpcode(Opcode.ARETURN);
	minfo.setCodeAttribute(code.toCodeAttribute());
	minfo.setAccessFlags(AccessFlag.PUBLIC);
	classfile.addMethod(minfo);
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addSetFieldHandlerMethod(ClassFile classfile)
		throws CannotCompileException {
	ConstPool cp = classfile.getConstPool();
	int this_class_index = cp.getThisClassInfo();
	MethodInfo minfo = new MethodInfo(cp, SETFIELDHANDLER_METHOD_NAME,
	                                  SETFIELDHANDLER_METHOD_DESCRIPTOR);
	/* local variables | this | callback | */
	Bytecode code = new Bytecode(cp, 3, 3);
	// aload_0 // load this
	code.addAload(0);
	// aload_1 // load callback
	code.addAload(1);
	// putfield // put field "$JAVASSIST_CALLBACK" defined already
	code.addOpcode(Opcode.PUTFIELD);
	int field_index = cp.addFieldrefInfo(this_class_index,
	                                     HANDLER_FIELD_NAME, HANDLER_FIELD_DESCRIPTOR);
	code.addIndex(field_index);
	// return
	code.addOpcode(Opcode.RETURN);
	minfo.setCodeAttribute(code.toCodeAttribute());
	minfo.setAccessFlags(AccessFlag.PUBLIC);
	classfile.addMethod(minfo);
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private static void addTypeDependDataReturn(Bytecode code, String typeName) {
	if ((typeName.charAt(0) == 'L')
	    && (typeName.charAt(typeName.length() - 1) == ';')
	    || (typeName.charAt(0) == '[')) {
		// reference type
		code.addOpcode(Opcode.ARETURN);
	} else if (typeName.equals("Z") || typeName.equals("B")
	           || typeName.equals("C") || typeName.equals("I")
	           || typeName.equals("S")) {
		// boolean, byte, char, int, short
		code.addOpcode(Opcode.IRETURN);
	} else if (typeName.equals("D")) {
		// double
		code.addOpcode(Opcode.DRETURN);
	} else if (typeName.equals("F")) {
		// float
		code.addOpcode(Opcode.FRETURN);
	} else if (typeName.equals("J")) {
		// long
		code.addOpcode(Opcode.LRETURN);
	} else {
		// bad type
		throw new RuntimeException("bad type: " + typeName);
	}
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addGetFieldHandlerMethod(ClassFile classfile) throws CannotCompileException, BadBytecode {
	final ConstPool constPool = classfile.getConstPool();
	final int thisClassInfo = constPool.getThisClassInfo();
	final MethodInfo getterMethodInfo = new MethodInfo(
			constPool,
			GETFIELDHANDLER_METHOD_NAME,
			GETFIELDHANDLER_METHOD_DESCRIPTOR
	);

	/* local variable | this | */
	final Bytecode code = new Bytecode( constPool, 2, 1 );
	// aload_0 // load this
	code.addAload( 0 );
	// getfield // get field "$JAVASSIST_CALLBACK" defined already
	code.addOpcode( Opcode.GETFIELD );
	final int fieldIndex = constPool.addFieldrefInfo( thisClassInfo, HANDLER_FIELD_NAME, HANDLER_FIELD_DESCRIPTOR );
	code.addIndex( fieldIndex );
	// areturn // return the value of the field
	code.addOpcode( Opcode.ARETURN );
	getterMethodInfo.setCodeAttribute( code.toCodeAttribute() );
	getterMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
	final CodeAttribute codeAttribute = getterMethodInfo.getCodeAttribute();
	if ( codeAttribute != null ) {
		final StackMapTable smt = MapMaker.make( classPool, getterMethodInfo );
		codeAttribute.setAttribute( smt );
	}
	classfile.addMethod( getterMethodInfo );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addSetFieldHandlerMethod(ClassFile classfile) throws CannotCompileException, BadBytecode {
	final ConstPool constPool = classfile.getConstPool();
	final int thisClassInfo = constPool.getThisClassInfo();
	final MethodInfo methodInfo = new MethodInfo(
			constPool,
			SETFIELDHANDLER_METHOD_NAME,
			SETFIELDHANDLER_METHOD_DESCRIPTOR
	);

	/* local variables | this | callback | */
	final Bytecode code = new Bytecode(constPool, 3, 3);
	// aload_0 : load this
	code.addAload( 0 );
	// aload_1 : load callback
	code.addAload( 1 );
	// putfield // put field "$JAVASSIST_CALLBACK" defined already
	code.addOpcode( Opcode.PUTFIELD );
	final int fieldIndex = constPool.addFieldrefInfo( thisClassInfo, HANDLER_FIELD_NAME, HANDLER_FIELD_DESCRIPTOR );
	code.addIndex( fieldIndex );
	// return
	code.addOpcode( Opcode.RETURN );
	methodInfo.setCodeAttribute( code.toCodeAttribute() );
	methodInfo.setAccessFlags( AccessFlag.PUBLIC );
	final CodeAttribute codeAttribute = methodInfo.getCodeAttribute();
	if ( codeAttribute != null ) {
		final StackMapTable smt = MapMaker.make( classPool, methodInfo );
		codeAttribute.setAttribute( smt );
	}
	classfile.addMethod( methodInfo );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private static void addTypeDependDataReturn(Bytecode code, String typeName) {
	if ( typeName.charAt( 0 ) == 'L'
			&& typeName.charAt( typeName.length() - 1 ) == ';'
			|| typeName.charAt( 0 ) == '[') {
		// reference type
		code.addOpcode( Opcode.ARETURN );
	}
	else if ( typeName.equals( "Z" )
			|| typeName.equals( "B" )
			|| typeName.equals( "C" )
			|| typeName.equals( "I" )
			|| typeName.equals( "S" ) ) {
		// boolean, byte, char, int, short
		code.addOpcode( Opcode.IRETURN );
	}
	else if ( typeName.equals( "D" ) ) {
		// double
		code.addOpcode( Opcode.DRETURN );
	}
	else if ( typeName.equals( "F" ) ) {
		// float
		code.addOpcode( Opcode.FRETURN );
	}
	else if ( typeName.equals( "J" ) ) {
		// long
		code.addOpcode( Opcode.LRETURN );
	}
	else {
		// bad type
		throw new RuntimeException( "bad type: " + typeName );
	}
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
static final void storeStack(CtClass[] params, boolean isStaticCall,
        int regno, Bytecode bytecode) {
    storeStack0(0, params.length, params, regno + 1, bytecode);
    if (isStaticCall)
        bytecode.addOpcode(ACONST_NULL);

    bytecode.addAstore(regno);
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private static void makeDefaultBody(Bytecode b, CtClass type) {
    int op;
    int value;
    if (type instanceof CtPrimitiveType) {
        CtPrimitiveType pt = (CtPrimitiveType)type;
        op = pt.getReturnOp();
        if (op == Opcode.DRETURN)
            value = Opcode.DCONST_0;
        else if (op == Opcode.FRETURN)
            value = Opcode.FCONST_0;
        else if (op == Opcode.LRETURN)
            value = Opcode.LCONST_0;
        else if (op == Opcode.RETURN)
            value = Opcode.NOP;
        else
            value = Opcode.ICONST_0;
    }
    else {
        op = Opcode.ARETURN;
        value = Opcode.ACONST_NULL;
    }

    if (value != Opcode.NOP)
        b.addOpcode(value);

    b.addOpcode(op);
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addGetter(ClassFile classfile, final Method[] getters) throws CannotCompileException {
	ConstPool cp = classfile.getConstPool();
	int target_type_index = cp.addClassInfo( this.targetBean.getName() );
	String desc = GET_SETTER_DESC;
	MethodInfo mi = new MethodInfo( cp, GENERATED_GETTER_NAME, desc );

	Bytecode code = new Bytecode( cp, 6, 4 );
	/* | this | bean | args | raw bean | */
	if ( getters.length >= 0 ) {
		// aload_1 // load bean
		code.addAload( 1 );
		// checkcast // cast bean
		code.addCheckcast( this.targetBean.getName() );
		// astore_3 // store bean
		code.addAstore( 3 );
		for ( int i = 0; i < getters.length; ++i ) {
			if ( getters[i] != null ) {
				Method getter = getters[i];
				// aload_2 // args
				code.addAload( 2 );
				// iconst_i // continue to aastore
				code.addIconst( i ); // growing stack is 1
				Class returnType = getter.getReturnType();
				int typeIndex = -1;
				if ( returnType.isPrimitive() ) {
					typeIndex = FactoryHelper.typeIndex( returnType );
					// new
					code.addNew( FactoryHelper.wrapperTypes[typeIndex] );
					// dup
					code.addOpcode( Opcode.DUP );
				}

				// aload_3 // load the raw bean
				code.addAload( 3 );
				String getter_desc = RuntimeSupport.makeDescriptor( getter );
				String getterName = getter.getName();
				if ( this.targetBean.isInterface() ) {
					// invokeinterface
					code.addInvokeinterface( target_type_index, getterName, getter_desc, 1 );
				}
				else {
					// invokevirtual
					code.addInvokevirtual( target_type_index, getterName, getter_desc );
				}

				if ( typeIndex >= 0 ) {       // is a primitive type
					// invokespecial
					code.addInvokespecial(
							FactoryHelper.wrapperTypes[typeIndex],
					        MethodInfo.nameInit,
					        FactoryHelper.wrapperDesc[typeIndex]
					);
				}

				// aastore // args
				code.add( Opcode.AASTORE );
				code.growStack( -3 );
			}
		}
	}
	// return
	code.addOpcode( Opcode.RETURN );

	mi.setCodeAttribute( code.toCodeAttribute() );
	mi.setAccessFlags( AccessFlag.PUBLIC );
	classfile.addMethod( mi );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
/**
 * Replaces creation of the array with the creation of the <em>KoratArray</em>
 * field. Just invokes its constructor with the <code>int</code> parameter
 * that represents the length of the array.
 * 
 * @param arrayType - 
 *            type of array in terms of JVM
 * @param cit -
 *            iterator through method's body code
 * @param idx -
 *            current position in the <code>cit</code>
 * @throws BadBytecode
 */
private void delegateNewArray(int arrayType, CodeIterator cit, int idx) {

    // check how this new array is going to be consumed
    if (operandStack.peek().consumedBy != ConsumedByKind.PUTFIELD)
        return;
    
    String koratClassName = koratArrayClassNames[arrayType];
    int locals = cit.get().getMaxLocals();
    int localVar1 = locals + 1;

    try {

        Bytecode codes = new Bytecode(constPool);
        codes.addIstore(localVar1);
        codes.addNew(koratClassName);
        codes.addOpcode(Opcode.DUP);
        codes.addIload(localVar1);
        String descr = Descriptor.ofMethod(CtClass.voidType,
                new CtClass[] { CtClass.intType });
        codes.addInvokespecial(koratClassName, "<init>", descr);

        int diff = codes.getSize() - 2;
        // -2 because original instruction
        // (NEWARRAY) is 2 bytes long.

        cit.insertGap(idx, diff);
        cit.write(codes.get(), idx);
        cit.get().setMaxLocals(localVar1 + 1);

    } catch (BadBytecode e) {
        throw new RuntimeException(e);
    }

}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addGetter(ClassFile classfile, final Method[] getters) throws CannotCompileException {
	final ConstPool constPool = classfile.getConstPool();
	final int targetBeanConstPoolIndex = constPool.addClassInfo( this.targetBean.getName() );
	final String desc = GET_SETTER_DESC;
	final MethodInfo getterMethodInfo = new MethodInfo( constPool, GENERATED_GETTER_NAME, desc );

	final Bytecode code = new Bytecode( constPool, 6, 4 );
	/* | this | bean | args | raw bean | */
	if ( getters.length >= 0 ) {
		// aload_1 // load bean
		code.addAload( 1 );
		// checkcast // cast bean
		code.addCheckcast( this.targetBean.getName() );
		// astore_3 // store bean
		code.addAstore( 3 );
		for ( int i = 0; i < getters.length; ++i ) {
			if ( getters[i] != null ) {
				final Method getter = getters[i];
				// aload_2 // args
				code.addAload( 2 );
				// iconst_i // continue to aastore
				// growing stack is 1
				code.addIconst( i );
				final Class returnType = getter.getReturnType();
				int typeIndex = -1;
				if ( returnType.isPrimitive() ) {
					typeIndex = FactoryHelper.typeIndex( returnType );
					// new
					code.addNew( FactoryHelper.wrapperTypes[typeIndex] );
					// dup
					code.addOpcode( Opcode.DUP );
				}

				// aload_3 // load the raw bean
				code.addAload( 3 );
				final String getterSignature = RuntimeSupport.makeDescriptor( getter );
				final String getterName = getter.getName();
				if ( this.targetBean.isInterface() ) {
					// invokeinterface
					code.addInvokeinterface( targetBeanConstPoolIndex, getterName, getterSignature, 1 );
				}
				else {
					// invokevirtual
					code.addInvokevirtual( targetBeanConstPoolIndex, getterName, getterSignature );
				}

				if ( typeIndex >= 0 ) {
					// is a primitive type
					// invokespecial
					code.addInvokespecial(
							FactoryHelper.wrapperTypes[typeIndex],
							MethodInfo.nameInit,
							FactoryHelper.wrapperDesc[typeIndex]
					);
				}

				// aastore // args
				code.add( Opcode.AASTORE );
				code.growStack( -3 );
			}
		}
	}
	// return
	code.addOpcode( Opcode.RETURN );

	getterMethodInfo.setCodeAttribute( code.toCodeAttribute() );
	getterMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
	classfile.addMethod( getterMethodInfo );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addReadMethod(ClassFile classfile, FieldInfo finfo) throws CannotCompileException, BadBytecode {
	final ConstPool constPool = classfile.getConstPool();
	final int thisClassInfo = constPool.getThisClassInfo();
	final String readMethodDescriptor = "()" + finfo.getDescriptor();
	final MethodInfo readMethodInfo = new MethodInfo(
			constPool,
			EACH_READ_METHOD_PREFIX + finfo.getName(),
			readMethodDescriptor
	);

	/* local variables | target obj | each oldvalue | */
	final Bytecode code = new Bytecode(constPool, 5, 3);
	// aload_0
	code.addAload( 0 );
	// getfield // get each field
	code.addOpcode( Opcode.GETFIELD );
	final int baseFieldIndex = constPool.addFieldrefInfo( thisClassInfo, finfo.getName(), finfo.getDescriptor() );
	code.addIndex( baseFieldIndex );
	// aload_0
	code.addAload( 0 );
	// invokeinterface : invoke Enabled.getInterceptFieldCallback()
	final int enabledClassIndex = constPool.addClassInfo( FIELD_HANDLED_TYPE_NAME );
	code.addInvokeinterface(
			enabledClassIndex,
			GETFIELDHANDLER_METHOD_NAME,
			GETFIELDHANDLER_METHOD_DESCRIPTOR,
			1
	);
	// ifnonnull
	code.addOpcode( Opcode.IFNONNULL );
	code.addIndex( 4 );
	// *return // each type
	addTypeDependDataReturn( code, finfo.getDescriptor() );
	// *store_1 // each type
	addTypeDependDataStore( code, finfo.getDescriptor(), 1 );
	// aload_0
	code.addAload( 0 );
	// invokeinterface // invoke Enabled.getInterceptFieldCallback()
	code.addInvokeinterface(
			enabledClassIndex,
			GETFIELDHANDLER_METHOD_NAME, GETFIELDHANDLER_METHOD_DESCRIPTOR,
			1
	);
	// aload_0
	code.addAload( 0 );
	// ldc // name of the field
	code.addLdc( finfo.getName() );
	// *load_1 // each type
	addTypeDependDataLoad( code, finfo.getDescriptor(), 1 );
	// invokeinterface // invoke Callback.read*() // each type
	addInvokeFieldHandlerMethod(
			classfile, code, finfo.getDescriptor(),
			true
	);
	// *return // each type
	addTypeDependDataReturn( code, finfo.getDescriptor() );

	readMethodInfo.setCodeAttribute( code.toCodeAttribute() );
	readMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
	final CodeAttribute codeAttribute = readMethodInfo.getCodeAttribute();
	if ( codeAttribute != null ) {
		final StackMapTable smt = MapMaker.make( classPool, readMethodInfo );
		codeAttribute.setAttribute( smt );
	}
	classfile.addMethod( readMethodInfo );
}
 

import javassist.bytecode.Bytecode; //导入方法依赖的package包/类
private void addWriteMethod(ClassFile classfile, FieldInfo finfo) throws CannotCompileException, BadBytecode {
	final ConstPool constPool = classfile.getConstPool();
	final int thisClassInfo = constPool.getThisClassInfo();
	final String writeMethodDescriptor = "(" + finfo.getDescriptor() + ")V";
	final MethodInfo writeMethodInfo = new MethodInfo(
			constPool,
			EACH_WRITE_METHOD_PREFIX+ finfo.getName(),
			writeMethodDescriptor
	);

	/* local variables | target obj | each oldvalue | */
	final Bytecode code = new Bytecode(constPool, 6, 3);
	// aload_0
	code.addAload( 0 );
	// invokeinterface : enabled.getInterceptFieldCallback()
	final int enabledClassIndex = constPool.addClassInfo( FIELD_HANDLED_TYPE_NAME );
	code.addInvokeinterface(
			enabledClassIndex,
			GETFIELDHANDLER_METHOD_NAME, GETFIELDHANDLER_METHOD_DESCRIPTOR,
			1
	);
	// ifnonnull (label1)
	code.addOpcode( Opcode.IFNONNULL );
	code.addIndex( 9 );
	// aload_0
	code.addAload( 0 );
	// *load_1
	addTypeDependDataLoad( code, finfo.getDescriptor(), 1 );
	// putfield
	code.addOpcode( Opcode.PUTFIELD );
	final int baseFieldIndex = constPool.addFieldrefInfo( thisClassInfo, finfo.getName(), finfo.getDescriptor() );
	code.addIndex( baseFieldIndex );
	code.growStack( -Descriptor.dataSize( finfo.getDescriptor() ) );
	// return ;
	code.addOpcode( Opcode.RETURN );
	// aload_0
	code.addAload( 0 );
	// dup
	code.addOpcode( Opcode.DUP );
	// invokeinterface // enabled.getInterceptFieldCallback()
	code.addInvokeinterface(
			enabledClassIndex,
			GETFIELDHANDLER_METHOD_NAME,
			GETFIELDHANDLER_METHOD_DESCRIPTOR,
			1
	);
	// aload_0
	code.addAload( 0 );
	// ldc // field name
	code.addLdc( finfo.getName() );
	// aload_0
	code.addAload( 0 );
	// getfield // old value of the field
	code.addOpcode( Opcode.GETFIELD );
	code.addIndex( baseFieldIndex );
	code.growStack( Descriptor.dataSize( finfo.getDescriptor() ) - 1 );
	// *load_1
	addTypeDependDataLoad( code, finfo.getDescriptor(), 1 );
	// invokeinterface // callback.write*(..)
	addInvokeFieldHandlerMethod( classfile, code, finfo.getDescriptor(), false );
	// putfield // new value of the field
	code.addOpcode( Opcode.PUTFIELD );
	code.addIndex( baseFieldIndex );
	code.growStack( -Descriptor.dataSize( finfo.getDescriptor() ) );
	// return
	code.addOpcode( Opcode.RETURN );

	writeMethodInfo.setCodeAttribute( code.toCodeAttribute() );
	writeMethodInfo.setAccessFlags( AccessFlag.PUBLIC );
	final CodeAttribute codeAttribute = writeMethodInfo.getCodeAttribute();
	if ( codeAttribute != null ) {
		final StackMapTable smt = MapMaker.make( classPool, writeMethodInfo );
		codeAttribute.setAttribute( smt );
	}
	classfile.addMethod( writeMethodInfo );
}