src/org/apache/xalan/xsltc/compiler/Param.java - xalan-java - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements. See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership. The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the  "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 /*
  * $Id$
  */

 package org.apache.xalan.xsltc.compiler;

 import org.apache.bcel.classfile.Field;
 import org.apache.bcel.generic.BranchHandle;
 import org.apache.bcel.generic.CHECKCAST;
 import org.apache.bcel.generic.IFNONNULL;
 import org.apache.bcel.generic.ConstantPoolGen;
 import org.apache.bcel.generic.INVOKEVIRTUAL;
 import org.apache.bcel.generic.Instruction;
 import org.apache.bcel.generic.InstructionList;
 import org.apache.bcel.generic.PUSH;
 import org.apache.bcel.generic.PUTFIELD;
 import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
 import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
 import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
 import org.apache.xalan.xsltc.compiler.util.ReferenceType;
 import org.apache.xalan.xsltc.compiler.util.Type;
 import org.apache.xalan.xsltc.compiler.util.ObjectType;
 import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
 import org.apache.xalan.xsltc.runtime.BasisLibrary;

 /**
  * @author Jacek Ambroziak
  * @author Santiago Pericas-Geertsen
  * @author Morten Jorgensen
  * @author Erwin Bolwidt <ejb@klomp.org>
  * @author John Howard <JohnH@schemasoft.com>
  */
 final class Param extends VariableBase {

     /**
      * True if this Param is declared in a simple named template.
      * This is used to optimize codegen for parameter passing
      * in named templates.
      */
     private boolean _isInSimpleNamedTemplate = false;

     /**
      * Display variable as single string
      */
     public String toString() {
 	return "param(" + _name + ")";
     }

     /**
      * Set the instruction for loading the value of this variable onto the
      * JVM stack and returns the old instruction.
      */
     public Instruction setLoadInstruction(Instruction instruction) {
         Instruction tmp = _loadInstruction;
         _loadInstruction = instruction;
         return tmp;
     }

     /**
      * Set the instruction for storing a value from the stack into this
      * variable and returns the old instruction.
      */
     public Instruction setStoreInstruction(Instruction instruction) {
         Instruction tmp = _storeInstruction;
         _storeInstruction = instruction;
         return tmp;
     }

     /**
      * Display variable in a full AST dump
      */
     public void display(int indent) {
 	indent(indent);
 	System.out.println("param " + _name);
 	if (_select != null) {
 	    indent(indent + IndentIncrement);
 	    System.out.println("select " + _select.toString());
 	}
 	displayContents(indent + IndentIncrement);
     }

     /**
      * Parse the contents of the <xsl:param> element. This method must read
      * the 'name' (required) and 'select' (optional) attributes.
      */
     public void parseContents(Parser parser) {

 	// Parse 'name' and 'select' attributes plus parameter contents
 	super.parseContents(parser);

 	// Add a ref to this param to its enclosing construct
 	final SyntaxTreeNode parent = getParent();
 	if (parent instanceof Stylesheet) {
 	    // Mark this as a global parameter
 	    _isLocal = false;
 	    // Check if a global variable with this name already exists...
 	    Param param = parser.getSymbolTable().lookupParam(_name);
 	    // ...and if it does we need to check import precedence
 	    if (param != null) {
 		final int us = this.getImportPrecedence();
 		final int them = param.getImportPrecedence();
 		// It is an error if the two have the same import precedence
 		if (us == them) {
 		    final String name = _name.toString();
 		    reportError(this, parser, ErrorMsg.VARIABLE_REDEF_ERR,name);
 		}
 		// Ignore this if previous definition has higher precedence
 		else if (them > us) {
 		    _ignore = true;
 		    return;
 		}
 		else {
 		    param.disable();
 		}
 	    }
 	    // Add this variable if we have higher precedence
 	    ((Stylesheet)parent).addParam(this);
 	    parser.getSymbolTable().addParam(this);
 	}
 	else if (parent instanceof Template) {
             Template template = (Template) parent;
 	    _isLocal = true;
             template.addParameter(this);
             if (template.isSimpleNamedTemplate()) {
                 _isInSimpleNamedTemplate = true;
             }
 	}
     }

     /**
      * Type-checks the parameter. The parameter type is determined by the
      * 'select' expression (if present) or is a result tree if the parameter
      * element has a body and no 'select' expression.
      */
     public Type typeCheck(SymbolTable stable) throws TypeCheckError {
 	if (_select != null) {
 	    _type = _select.typeCheck(stable);
 	    if (_type instanceof ReferenceType == false && !(_type instanceof ObjectType)) {
 		_select = new CastExpr(_select, Type.Reference);
 	    }
 	}
 	else if (hasContents()) {
 	    typeCheckContents(stable);
 	}
 	_type = Type.Reference;

 	// This element has no type (the parameter does, but the parameter
 	// element itself does not).
 	return Type.Void;
     }

     public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
 	final ConstantPoolGen cpg = classGen.getConstantPool();
 	final InstructionList il = methodGen.getInstructionList();

 	if (_ignore) return;
 	_ignore = true;

         /*
          * To fix bug 24518 related to setting parameters of the form
          * {namespaceuri}localName which will get mapped to an instance
          * variable in the class.
          */
 	final String name = BasisLibrary.mapQNameToJavaName(_name.toString());
 	final String signature = _type.toSignature();
 	final String className = _type.getClassName();

 	if (isLocal()) {
             /*
               * If simple named template then generate a conditional init of the
               * param using its default value:
               *       if (param == null) param = <default-value>
               */
             if (_isInSimpleNamedTemplate) {
 		il.append(loadInstruction());
                 BranchHandle ifBlock = il.append(new IFNONNULL(null));
                 translateValue(classGen, methodGen);
                 il.append(storeInstruction());
                 ifBlock.setTarget(il.append(NOP));
                 return;
             }

 	    il.append(classGen.loadTranslet());
 	    il.append(new PUSH(cpg, name));
 	    translateValue(classGen, methodGen);
 	    il.append(new PUSH(cpg, true));

 	    // Call addParameter() from this class
 	    il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
 							 ADD_PARAMETER,
 							 ADD_PARAMETER_SIG)));
 	    if (className != EMPTYSTRING) {
 		il.append(new CHECKCAST(cpg.addClass(className)));
 	    }

 	    _type.translateUnBox(classGen, methodGen);

 	    if (_refs.isEmpty()) { // nobody uses the value
 		il.append(_type.POP());
 		_local = null;
 	    }
 	    else {		// normal case
 		_local = methodGen.addLocalVariable2(name,
 						     _type.toJCType(),
 						     null);
 		// Cache the result of addParameter() in a local variable
 		_local.setStart(il.append(_type.STORE(_local.getIndex())));
 	    }
 	}
 	else {
 	    if (classGen.containsField(name) == null) {
 		classGen.addField(new Field(ACC_PUBLIC, cpg.addUtf8(name),
 					    cpg.addUtf8(signature),
 					    null, cpg.getConstantPool()));
 		il.append(classGen.loadTranslet());
 		il.append(DUP);
 		il.append(new PUSH(cpg, name));
 		translateValue(classGen, methodGen);
 		il.append(new PUSH(cpg, true));

 		// Call addParameter() from this class
 		il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
 						     ADD_PARAMETER,
 						     ADD_PARAMETER_SIG)));

 		_type.translateUnBox(classGen, methodGen);

 		// Cache the result of addParameter() in a field
 		if (className != EMPTYSTRING) {
 		    il.append(new CHECKCAST(cpg.addClass(className)));
 		}
 		il.append(new PUTFIELD(cpg.addFieldref(classGen.getClassName(),
 						       name, signature)));
 	    }
 	}
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	/*
	* $Id$
	*/

	package org.apache.xalan.xsltc.compiler;

	import org.apache.bcel.classfile.Field;
	import org.apache.bcel.generic.BranchHandle;
	import org.apache.bcel.generic.CHECKCAST;
	import org.apache.bcel.generic.IFNONNULL;
	import org.apache.bcel.generic.ConstantPoolGen;
	import org.apache.bcel.generic.INVOKEVIRTUAL;
	import org.apache.bcel.generic.Instruction;
	import org.apache.bcel.generic.InstructionList;
	import org.apache.bcel.generic.PUSH;
	import org.apache.bcel.generic.PUTFIELD;
	import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
	import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
	import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
	import org.apache.xalan.xsltc.compiler.util.ReferenceType;
	import org.apache.xalan.xsltc.compiler.util.Type;
	import org.apache.xalan.xsltc.compiler.util.ObjectType;
	import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
	import org.apache.xalan.xsltc.runtime.BasisLibrary;

	/**
	* @author Jacek Ambroziak
	* @author Santiago Pericas-Geertsen
	* @author Morten Jorgensen
	* @author Erwin Bolwidt <ejb@klomp.org>
	* @author John Howard <JohnH@schemasoft.com>
	*/
	final class Param extends VariableBase {

	/**
	* True if this Param is declared in a simple named template.
	* This is used to optimize codegen for parameter passing
	* in named templates.
	*/
	private boolean _isInSimpleNamedTemplate = false;

	/**
	* Display variable as single string
	*/
	public String toString() {
	return "param(" + _name + ")";
	}

	/**
	* Set the instruction for loading the value of this variable onto the
	* JVM stack and returns the old instruction.
	*/
	public Instruction setLoadInstruction(Instruction instruction) {
	Instruction tmp = _loadInstruction;
	_loadInstruction = instruction;
	return tmp;
	}

	/**
	* Set the instruction for storing a value from the stack into this
	* variable and returns the old instruction.
	*/
	public Instruction setStoreInstruction(Instruction instruction) {
	Instruction tmp = _storeInstruction;
	_storeInstruction = instruction;
	return tmp;
	}

	/**
	* Display variable in a full AST dump
	*/
	public void display(int indent) {
	indent(indent);
	System.out.println("param " + _name);
	if (_select != null) {
	indent(indent + IndentIncrement);
	System.out.println("select " + _select.toString());
	}
	displayContents(indent + IndentIncrement);
	}

	/**
	* Parse the contents of the <xsl:param> element. This method must read
	* the 'name' (required) and 'select' (optional) attributes.
	*/
	public void parseContents(Parser parser) {

	// Parse 'name' and 'select' attributes plus parameter contents
	super.parseContents(parser);

	// Add a ref to this param to its enclosing construct
	final SyntaxTreeNode parent = getParent();
	if (parent instanceof Stylesheet) {
	// Mark this as a global parameter
	_isLocal = false;
	// Check if a global variable with this name already exists...
	Param param = parser.getSymbolTable().lookupParam(_name);
	// ...and if it does we need to check import precedence
	if (param != null) {
	final int us = this.getImportPrecedence();
	final int them = param.getImportPrecedence();
	// It is an error if the two have the same import precedence
	if (us == them) {
	final String name = _name.toString();
	reportError(this, parser, ErrorMsg.VARIABLE_REDEF_ERR,name);
	}
	// Ignore this if previous definition has higher precedence
	else if (them > us) {
	_ignore = true;
	return;
	}
	else {
	param.disable();
	}
	}
	// Add this variable if we have higher precedence
	((Stylesheet)parent).addParam(this);
	parser.getSymbolTable().addParam(this);
	}
	else if (parent instanceof Template) {
	Template template = (Template) parent;
	_isLocal = true;
	template.addParameter(this);
	if (template.isSimpleNamedTemplate()) {
	_isInSimpleNamedTemplate = true;
	}
	}
	}

	/**
	* Type-checks the parameter. The parameter type is determined by the
	* 'select' expression (if present) or is a result tree if the parameter
	* element has a body and no 'select' expression.
	*/
	public Type typeCheck(SymbolTable stable) throws TypeCheckError {
	if (_select != null) {
	_type = _select.typeCheck(stable);
	if (_type instanceof ReferenceType == false && !(_type instanceof ObjectType)) {
	_select = new CastExpr(_select, Type.Reference);
	}
	}
	else if (hasContents()) {
	typeCheckContents(stable);
	}
	_type = Type.Reference;

	// This element has no type (the parameter does, but the parameter
	// element itself does not).
	return Type.Void;
	}

	public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

	if (_ignore) return;
	_ignore = true;

	/*
	* To fix bug 24518 related to setting parameters of the form
	* {namespaceuri}localName which will get mapped to an instance
	* variable in the class.
	*/
	final String name = BasisLibrary.mapQNameToJavaName(_name.toString());
	final String signature = _type.toSignature();
	final String className = _type.getClassName();

	if (isLocal()) {
	/*
	* If simple named template then generate a conditional init of the
	* param using its default value:
	* if (param == null) param = <default-value>
	*/
	if (_isInSimpleNamedTemplate) {
	il.append(loadInstruction());
	BranchHandle ifBlock = il.append(new IFNONNULL(null));
	translateValue(classGen, methodGen);
	il.append(storeInstruction());
	ifBlock.setTarget(il.append(NOP));
	return;
	}

	il.append(classGen.loadTranslet());
	il.append(new PUSH(cpg, name));
	translateValue(classGen, methodGen);
	il.append(new PUSH(cpg, true));

	// Call addParameter() from this class
	il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
	ADD_PARAMETER,
	ADD_PARAMETER_SIG)));
	if (className != EMPTYSTRING) {
	il.append(new CHECKCAST(cpg.addClass(className)));
	}

	_type.translateUnBox(classGen, methodGen);

	if (_refs.isEmpty()) { // nobody uses the value
	il.append(_type.POP());
	_local = null;
	}
	else { // normal case
	_local = methodGen.addLocalVariable2(name,
	_type.toJCType(),
	null);
	// Cache the result of addParameter() in a local variable
	_local.setStart(il.append(_type.STORE(_local.getIndex())));
	}
	}
	else {
	if (classGen.containsField(name) == null) {
	classGen.addField(new Field(ACC_PUBLIC, cpg.addUtf8(name),
	cpg.addUtf8(signature),
	null, cpg.getConstantPool()));
	il.append(classGen.loadTranslet());
	il.append(DUP);
	il.append(new PUSH(cpg, name));
	translateValue(classGen, methodGen);
	il.append(new PUSH(cpg, true));

	// Call addParameter() from this class
	il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
	ADD_PARAMETER,
	ADD_PARAMETER_SIG)));

	_type.translateUnBox(classGen, methodGen);

	// Cache the result of addParameter() in a field
	if (className != EMPTYSTRING) {
	il.append(new CHECKCAST(cpg.addClass(className)));
	}
	il.append(new PUTFIELD(cpg.addFieldref(classGen.getClassName(),
	name, signature)));
	}
	}
	}
	}