functioncall.java

java1.6众多例子参考

		    if (local.indexOf('-') > 0) {
		        local = replaceDash(local);
		    }
		    
		    String extFunction = (String)_extensionFunctionTable.get(namespace + ":" + local);
		    if (extFunction != null) {
		      	_fname = new QName(null, null, extFunction);
		      	return typeCheckStandard(stable);
		    }
		    else
		      	_fname = new QName(namespace, null, local);
		}
		  
		return typeCheckExternal(stable);
	    } 
	    catch (TypeCheckError e) {
		ErrorMsg errorMsg = e.getErrorMsg();
		if (errorMsg == null) {
		    final String name = _fname.getLocalPart();
		    errorMsg = new ErrorMsg(ErrorMsg.METHOD_NOT_FOUND_ERR, name);
		}
		getParser().reportError(ERROR, errorMsg);
		return _type = Type.Void;
	    }
	  }
    }

    /**
     * Type check a call to a standard function. Insert CastExprs when needed.
     * If as a result of the insertion of a CastExpr a type check error is 
     * thrown, then catch it and re-throw it with a new "this".
     */
    public Type typeCheckStandard(SymbolTable stable) throws TypeCheckError {
	_fname.clearNamespace(); 	// HACK!!!

	final int n = _arguments.size();
	final Vector argsType = typeCheckArgs(stable);
	final MethodType args = new MethodType(Type.Void, argsType);
	final MethodType ptype =
	    lookupPrimop(stable, _fname.getLocalPart(), args);

	if (ptype != null) {
	    for (int i = 0; i < n; i++) {
		final Type argType = (Type) ptype.argsType().elementAt(i);
		final Expression exp = (Expression)_arguments.elementAt(i);
		if (!argType.identicalTo(exp.getType())) {
		    try {
			_arguments.setElementAt(new CastExpr(exp, argType), i);
		    }
		    catch (TypeCheckError e) {
			throw new TypeCheckError(this);	// invalid conversion
		    }
		}
	    }
	    _chosenMethodType = ptype;
	    return _type = ptype.resultType();
	}
	throw new TypeCheckError(this);
    }

   

    public Type typeCheckConstructor(SymbolTable stable) throws TypeCheckError{
        final Vector constructors = findConstructors();
	if (constructors == null) {
            // Constructor not found in this class
            throw new TypeCheckError(ErrorMsg.CONSTRUCTOR_NOT_FOUND, 
		_className);
        
	}

	final int nConstructors = constructors.size();
	final int nArgs = _arguments.size();
	final Vector argsType = typeCheckArgs(stable);

	// Try all constructors 
	int bestConstrDistance = Integer.MAX_VALUE;
	_type = null;			// reset
	for (int j, i = 0; i < nConstructors; i++) {
	    // Check if all parameters to this constructor can be converted
	    final Constructor constructor = 
		(Constructor)constructors.elementAt(i);
	    final Class[] paramTypes = constructor.getParameterTypes();

	    Class extType = null;
	    int currConstrDistance = 0;
	    for (j = 0; j < nArgs; j++) {
		// Convert from internal (translet) type to external (Java) type
		extType = paramTypes[j];
		final Type intType = (Type)argsType.elementAt(j);
		Object match = _internal2Java.maps(intType, extType);
		if (match != null) {
		    currConstrDistance += ((JavaType)match).distance;
		}
		else if (intType instanceof ObjectType) {
		    ObjectType objectType = (ObjectType)intType;
		    if (objectType.getJavaClass() == extType)
		        continue;
		    else if (extType.isAssignableFrom(objectType.getJavaClass()))
		        currConstrDistance += 1;
		    else {
			currConstrDistance = Integer.MAX_VALUE;
			break;
		    }
		}
		else {
		    // no mapping available
		    currConstrDistance = Integer.MAX_VALUE;
		    break;
		} 
	    }

	    if (j == nArgs && currConstrDistance < bestConstrDistance ) {
	        _chosenConstructor = constructor;
	        _isExtConstructor = true;
		bestConstrDistance = currConstrDistance;
		
                _type = (_clazz != null) ? Type.newObjectType(_clazz)
                    : Type.newObjectType(_className);
	    }
	}

	if (_type != null) {
	    return _type;
	}

	throw new TypeCheckError(ErrorMsg.ARGUMENT_CONVERSION_ERR, getMethodSignature(argsType));
    }


    /**
     * Type check a call to an external (Java) method.
     * The method must be static an public, and a legal type conversion
     * must exist for all its arguments and its return type.
     * Every method of name <code>_fname</code> is inspected
     * as a possible candidate.
     */
    public Type typeCheckExternal(SymbolTable stable) throws TypeCheckError {
	int nArgs = _arguments.size();
	final String name = _fname.getLocalPart();
    
 	// check if function is a contructor 'new'
	if (_fname.getLocalPart().equals("new")) {
	    return typeCheckConstructor(stable);
	}
	// check if we are calling an instance method
	else {
	    boolean hasThisArgument = false;
	  
	    if (nArgs == 0)
	        _isStatic = true;
	  
	    if (!_isStatic) {
	        if (_namespace_format == NAMESPACE_FORMAT_JAVA
	  	    || _namespace_format == NAMESPACE_FORMAT_PACKAGE)
	   	    hasThisArgument = true;
	  	  
	  	Expression firstArg = (Expression)_arguments.elementAt(0);
	  	Type firstArgType = (Type)firstArg.typeCheck(stable);
	  	
	  	if (_namespace_format == NAMESPACE_FORMAT_CLASS
	  	    && firstArgType instanceof ObjectType
	  	    && _clazz != null
	  	    && _clazz.isAssignableFrom(((ObjectType)firstArgType).getJavaClass()))
	  	    hasThisArgument = true;
	  	
	  	if (hasThisArgument) {
	  	    _thisArgument = (Expression) _arguments.elementAt(0);
	  	    _arguments.remove(0); nArgs--;
		    if (firstArgType instanceof ObjectType) {
		    	_className = ((ObjectType) firstArgType).getJavaClassName();
		    }
		    else
		    	throw new TypeCheckError(ErrorMsg.NO_JAVA_FUNCT_THIS_REF, name);  	  	
	  	}
	    }
	    else if (_className.length() == 0) {
		/*
		 * Warn user if external function could not be resolved.
		 * Warning will _NOT_ be issued is the call is properly
		 * wrapped in an <xsl:if> or <xsl:when> element. For details
		 * see If.parserContents() and When.parserContents()
		 */
		final Parser parser = getParser();
		if (parser != null) {
		    reportWarning(this, parser, ErrorMsg.FUNCTION_RESOLVE_ERR,
				  _fname.toString());
		}
		unresolvedExternal = true;
		return _type = Type.Int;	// use "Int" as "unknown"
	    }
	}
	
	final Vector methods = findMethods();
	
	if (methods == null) {
	    // Method not found in this class
	    throw new TypeCheckError(ErrorMsg.METHOD_NOT_FOUND_ERR, _className + "." + name);
	}

	Class extType = null;
	final int nMethods = methods.size();
	final Vector argsType = typeCheckArgs(stable);

	// Try all methods to identify the best fit 
	int bestMethodDistance  = Integer.MAX_VALUE;
	_type = null;                       // reset internal type 
	for (int j, i = 0; i < nMethods; i++) {
	    // Check if all paramteters to this method can be converted
	    final Method method = (Method)methods.elementAt(i);
	    final Class[] paramTypes = method.getParameterTypes();
	    
	    int currMethodDistance = 0;
	    for (j = 0; j < nArgs; j++) {
		// Convert from internal (translet) type to external (Java) type
		extType = paramTypes[j];
		final Type intType = (Type)argsType.elementAt(j);
		Object match = _internal2Java.maps(intType, extType);
		if (match != null) {
		    currMethodDistance += ((JavaType)match).distance; 
		}
		else {
		    // no mapping available
		    //
		    // Allow a Reference type to match any external (Java) type at
		    // the moment. The real type checking is performed at runtime.
		    if (intType instanceof ReferenceType) {
		       currMethodDistance += 1; 
		    }
		    else if (intType instanceof ObjectType) {
		        ObjectType object = (ObjectType)intType;
		        if (extType.getName().equals(object.getJavaClassName()))
		            currMethodDistance += 0;
		      	else if (extType.isAssignableFrom(object.getJavaClass()))
		            currMethodDistance += 1;
		      	else {
		      	    currMethodDistance = Integer.MAX_VALUE;
		      	    break;
		        }
		    }
		    else {
		        currMethodDistance = Integer.MAX_VALUE;
		        break;
		    }
		}
	    }

	    if (j == nArgs) {
		  // Check if the return type can be converted
		  extType = method.getReturnType();
		
		  _type = (Type) _java2Internal.get(extType);
		  if (_type == null) {
		      _type = Type.newObjectType(extType);
		  }		

		  // Use this method if all parameters & return type match
		  if (_type != null && currMethodDistance < bestMethodDistance) {
		      _chosenMethod = method;
		      bestMethodDistance = currMethodDistance;
		  }
	    }
	}
	
	// It is an error if the chosen method is an instance menthod but we don't
	// have a this argument.
	if (_chosenMethod != null && _thisArgument == null &&
	    !Modifier.isStatic(_chosenMethod.getModifiers())) {
	    throw new TypeCheckError(ErrorMsg.NO_JAVA_FUNCT_THIS_REF, getMethodSignature(argsType));
	}

	if (_type != null) {
	    if (_type == Type.NodeSet) {
            	getXSLTC().setMultiDocument(true);
            }
	    return _type;
	}

	throw new TypeCheckError(ErrorMsg.ARGUMENT_CONVERSION_ERR, getMethodSignature(argsType));
    }

    /**
     * Type check the actual arguments of this function call.
     */
    public Vector typeCheckArgs(SymbolTable stable) throws TypeCheckError {
	final Vector result = new Vector();
	final Enumeration e = _arguments.elements();	
	while (e.hasMoreElements()) {
	    final Expression exp = (Expression)e.nextElement();
	    result.addElement(exp.typeCheck(stable));
	}
	return result;
    }

    protected final Expression argument(int i) {
	return (Expression)_arguments.elementAt(i);
    }

    protected final Expression argument() {
	return argument(0);
    }
    
    protected final int argumentCount() {
	return _arguments.size();
    }

    protected final void setArgument(int i, Expression exp) {
	_arguments.setElementAt(exp, i);
    }

    /**
     * Compile the function call and treat as an expression
     * Update true/false-lists.
     */
    public void translateDesynthesized(ClassGenerator classGen,
				       MethodGenerator methodGen) 
    {
	Type type = Type.Boolean;
	if (_chosenMethodType != null)
	    type = _chosenMethodType.resultType();

	final InstructionList il = methodGen.getInstructionList();
	translate(classGen, methodGen);

	if ((type instanceof BooleanType) || (type instanceof IntType)) {
	    _falseList.add(il.append(new IFEQ(null)));
	}
    }


    /**
     * Translate a function call. The compiled code will leave the function's
     * return value on the JVM's stack.
     */
    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	final int n = argumentCount();
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();
	final boolean isSecureProcessing = classGen.getParser().getXSLTC().isSecureProcessing();
	int index;

	// Translate calls to methods in the BasisLibrary
	if (isStandard() || isExtension()) {
	    for (int i = 0; i < n; i++) {
		final Expression exp = argument(i);
		exp.translate(classGen, methodGen);
		exp.startIterator(classGen, methodGen);
	    }

	    // append "F" to the function's name
	    final String name = _fname.toString().replace('-', '_') + "F";
	    String args = Constants.EMPTYSTRING;

	    // Special precautions for some method calls
	    if (name.equals("sumF")) {
		args = DOM_INTF_SIG;
		il.append(methodGen.loadDOM());
	    }
	    else if (name.equals("normalize_spaceF")) {
		if (_chosenMethodType.toSignature(args).
		    equals("()Ljava/lang/String;")) {
		    args = "I"+DOM_INTF_SIG;
		    il.append(methodGen.loadContextNode());
		    il.append(methodGen.loadDOM());