import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    if (_select != null) {
        _type = _select.typeCheck(stable);
        if (_type instanceof NodeType || _type instanceof ReferenceType) {
            _select = new CastExpr(_select, Type.NodeSet);
            _type = Type.NodeSet;
        }
        if (_type instanceof NodeSetType||_type instanceof ResultTreeType) {
            typeCheckContents(stable); // with-params
            return Type.Void;
        }
        throw new TypeCheckError(this);
    }
    else {
        typeCheckContents(stable);          // with-params
        return Type.Void;
    }
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
/**
 * Type checking a cast expression amounts to verifying that the
 * type conversion is legal. Cast expressions are created during
 * type checking, but typeCheck() is usually not called on them.
 * As a result, this method is called from the constructor.
 */
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    Type tleft = _left.getType();
    if (tleft == null) {
        tleft = _left.typeCheck(stable);
    }
    if (tleft instanceof NodeType) {
        tleft = Type.Node;  // multiple instances
    }
    else if (tleft instanceof ResultTreeType) {
        tleft = Type.ResultTree; // multiple instances
    }
    if (InternalTypeMap.maps(tleft, _type) != null) {
        return _type;
    }
    // throw new TypeCheckError(this);
    throw new TypeCheckError(new ErrorMsg(
        ErrorMsg.DATA_CONVERSION_ERR, tleft.toString(), _type.toString()));
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
/**
 * Remove the mapping of this variable to a register.
 * Called when we leave the AST scope of the variable's declaration
 */
public void unmapRegister(ClassGenerator classGen, MethodGenerator methodGen) {
    if (_local != null) {
        if (_type instanceof ResultTreeType) {
            final ConstantPoolGen cpg = classGen.getConstantPool();
            final InstructionList il = methodGen.getInstructionList();
            if (classGen.getStylesheet().callsNodeset() && classGen.getDOMClass().equals(MULTI_DOM_CLASS)) {
                final int removeDA = cpg.addMethodref(MULTI_DOM_CLASS, "removeDOMAdapter", "(" + DOM_ADAPTER_SIG + ")V");
                il.append(methodGen.loadDOM());
                il.append(new CHECKCAST(cpg.addClass(MULTI_DOM_CLASS)));
                il.append(loadInstruction());
                il.append(new CHECKCAST(cpg.addClass(DOM_ADAPTER_CLASS)));
                il.append(new INVOKEVIRTUAL(removeDA));
            }
            final int release = cpg.addInterfaceMethodref(DOM_IMPL_CLASS, "release", "()V");
            il.append(loadInstruction());
            il.append(new INVOKEINTERFACE(release, 1));
        }

        _local.setEnd(methodGen.getInstructionList().getEnd());
        methodGen.removeLocalVariable(_local);
        _refs = null;
        _local = null;
    }
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    _type = _select.typeCheck(stable);

    if (_type instanceof ReferenceType || _type instanceof NodeType) {
        _select = new CastExpr(_select, Type.NodeSet);
        typeCheckContents(stable);
        return Type.Void;
    }
    if (_type instanceof NodeSetType||_type instanceof ResultTreeType) {
        typeCheckContents(stable);
        return Type.Void;
    }
    throw new TypeCheckError(this);
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    final Type tselect = _select.typeCheck(stable);
    if (tselect instanceof NodeType ||
        tselect instanceof NodeSetType ||
        tselect instanceof ReferenceType ||
        tselect instanceof ResultTreeType) {
        // falls through
    }
    else {
        _select = new CastExpr(_select, Type.String);
    }
    return Type.Void;
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    // Save current node and current iterator on the stack
    il.append(methodGen.loadCurrentNode());
    il.append(methodGen.loadIterator());

    // Collect sort objects associated with this instruction
    final Vector sortObjects = new Vector();
    Enumeration children = elements();
    while (children.hasMoreElements()) {
        final Object child = children.nextElement();
        if (child instanceof Sort) {
            sortObjects.addElement(child);
        }
    }

    if ((_type != null) && (_type instanceof ResultTreeType)) {
        // Store existing DOM on stack - must be restored when loop is done
        il.append(methodGen.loadDOM());

        // <xsl:sort> cannot be applied to a result tree - issue warning
        if (sortObjects.size() > 0) {
            ErrorMsg msg = new ErrorMsg(ErrorMsg.RESULT_TREE_SORT_ERR,this);
            getParser().reportError(WARNING, msg);
        }

        // Put the result tree on the stack (DOM)
        _select.translate(classGen, methodGen);
        // Get an iterator for the whole DOM - excluding the root node
        _type.translateTo(classGen, methodGen, Type.NodeSet);
        // Store the result tree as the default DOM
        il.append(SWAP);
        il.append(methodGen.storeDOM());
    }
    else {
        // Compile node iterator
        if (sortObjects.size() > 0) {
            Sort.translateSortIterator(classGen, methodGen,
                                       _select, sortObjects);
        }
        else {
            _select.translate(classGen, methodGen);
        }

        if (_type instanceof ReferenceType == false) {
            il.append(methodGen.loadContextNode());
            il.append(methodGen.setStartNode());
        }
    }


    // Overwrite current iterator
    il.append(methodGen.storeIterator());

    // Give local variables (if any) default values before starting loop
    initializeVariables(classGen, methodGen);

    final BranchHandle nextNode = il.append(new GOTO(null));
    final InstructionHandle loop = il.append(NOP);

    translateContents(classGen, methodGen);

    nextNode.setTarget(il.append(methodGen.loadIterator()));
    il.append(methodGen.nextNode());
    il.append(DUP);
    il.append(methodGen.storeCurrentNode());
    il.append(new IFGT(loop));

    // Restore current DOM (if result tree was used instead for this loop)
    if ((_type != null) && (_type instanceof ResultTreeType)) {
        il.append(methodGen.storeDOM());
    }

    // Restore current node and current iterator from the stack
    il.append(methodGen.storeIterator());
    il.append(methodGen.storeCurrentNode());
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
/**
 * Typing rules: see XSLT Reference by M. Kay page 345.
 */
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    final Type tleft = _left.typeCheck(stable);
    final Type tright = _right.typeCheck(stable);

    if (tleft.isSimple() && tright.isSimple()) {
        if (tleft != tright) {
            if (tleft instanceof BooleanType) {
                _right = new CastExpr(_right, Type.Boolean);
            }
            else if (tright instanceof BooleanType) {
                _left = new CastExpr(_left, Type.Boolean);
            }
            else if (tleft instanceof NumberType ||
                     tright instanceof NumberType) {
                _left = new CastExpr(_left, Type.Real);
                _right = new CastExpr(_right, Type.Real);
            }
            else {          // both compared as strings
                _left = new CastExpr(_left,   Type.String);
                _right = new CastExpr(_right, Type.String);
            }
        }
    }
    else if (tleft instanceof ReferenceType) {
        _right = new CastExpr(_right, Type.Reference);
    }
    else if (tright instanceof ReferenceType) {
        _left = new CastExpr(_left, Type.Reference);
    }
    // the following 2 cases optimize @attr|.|.. = 'string'
    else if (tleft instanceof NodeType && tright == Type.String) {
        _left = new CastExpr(_left, Type.String);
    }
    else if (tleft == Type.String && tright instanceof NodeType) {
        _right = new CastExpr(_right, Type.String);
    }
    // optimize node/node
    else if (tleft instanceof NodeType && tright instanceof NodeType) {
        _left = new CastExpr(_left, Type.String);
        _right = new CastExpr(_right, Type.String);
    }
    else if (tleft instanceof NodeType && tright instanceof NodeSetType) {
        // compare(Node, NodeSet) will be invoked
    }
    else if (tleft instanceof NodeSetType && tright instanceof NodeType) {
        swapArguments();    // for compare(Node, NodeSet)
    }
    else {
        // At least one argument is of type node, node-set or result-tree

        // Promote an expression of type node to node-set
        if (tleft instanceof NodeType) {
            _left = new CastExpr(_left, Type.NodeSet);
        }
        if (tright instanceof NodeType) {
            _right = new CastExpr(_right, Type.NodeSet);
        }

        // If one arg is a node-set then make it the left one
        if (tleft.isSimple() ||
            tleft instanceof ResultTreeType &&
            tright instanceof NodeSetType) {
            swapArguments();
        }

        // Promote integers to doubles to have fewer compares
        if (_right.getType() instanceof IntType) {
            _right = new CastExpr(_right, Type.Real);
        }
    }
    return _type = Type.Boolean;
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
/**
 * Type check a predicate expression. If the type of the expression is
 * number convert it to boolean by adding a comparison with position().
 * Note that if the expression is a parameter, we cannot distinguish
 * at compile time if its type is number or not. Hence, expressions of
 * reference type are always converted to booleans.
 *
 * This method may be called twice, before and after calling
 * <code>dontOptimize()</code>. If so, the second time it should honor
 * the new value of <code>_canOptimize</code>.
 */
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    Type texp = _exp.typeCheck(stable);

    // We need explicit type information for reference types - no good!
    if (texp instanceof ReferenceType) {
        _exp = new CastExpr(_exp, texp = Type.Real);
    }

    // A result tree fragment should not be cast directly to a number type,
    // but rather to a boolean value, and then to a numer (0 or 1).
    // Ref. section 11.2 of the XSLT 1.0 spec
    if (texp instanceof ResultTreeType) {
        _exp = new CastExpr(_exp, Type.Boolean);
        _exp = new CastExpr(_exp, Type.Real);
        texp = _exp.typeCheck(stable);
    }

    // Numerical types will be converted to a position filter
    if (texp instanceof NumberType) {
        // Cast any numerical types to an integer
        if (texp instanceof IntType == false) {
            _exp = new CastExpr(_exp, Type.Int);
        }

        if (_canOptimize) {
            // Nth position optimization. Expression must not depend on context
            _nthPositionFilter =
                !_exp.hasLastCall() && !_exp.hasPositionCall();

            // _nthDescendant optimization - only if _nthPositionFilter is on
            if (_nthPositionFilter) {
                SyntaxTreeNode parent = getParent();
                _nthDescendant = (parent instanceof Step) &&
                    (parent.getParent() instanceof AbsoluteLocationPath);
                return _type = Type.NodeSet;
            }
        }

       // Reset optimization flags
        _nthPositionFilter = _nthDescendant = false;

       // Otherwise, expand [e] to [position() = e]
       final QName position =
            getParser().getQNameIgnoreDefaultNs("position");
       final PositionCall positionCall =
            new PositionCall(position);
       positionCall.setParser(getParser());
       positionCall.setParent(this);

       _exp = new EqualityExpr(Operators.EQ, positionCall,
                                _exp);
       if (_exp.typeCheck(stable) != Type.Boolean) {
           _exp = new CastExpr(_exp, Type.Boolean);
       }
       return _type = Type.Boolean;
    }
    else {
        // All other types will be handled as boolean values
        if (texp instanceof BooleanType == false) {
            _exp = new CastExpr(_exp, Type.Boolean);
        }
        return _type = Type.Boolean;
    }
}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    final Type tselect = _select.getType();

    final String CPY1_SIG = "("+NODE_ITERATOR_SIG+TRANSLET_OUTPUT_SIG+")V";
    final int cpy1 = cpg.addInterfaceMethodref(DOM_INTF, "copy", CPY1_SIG);

    final String CPY2_SIG = "("+NODE_SIG+TRANSLET_OUTPUT_SIG+")V";
    final int cpy2 = cpg.addInterfaceMethodref(DOM_INTF, "copy", CPY2_SIG);

    final String getDoc_SIG = "()"+NODE_SIG;
    final int getDoc = cpg.addInterfaceMethodref(DOM_INTF, "getDocument", getDoc_SIG);


    if (tselect instanceof NodeSetType) {
        il.append(methodGen.loadDOM());

        // push NodeIterator
        _select.translate(classGen, methodGen);
        _select.startIterator(classGen, methodGen);

        // call copy from the DOM 'library'
        il.append(methodGen.loadHandler());
        il.append(new INVOKEINTERFACE(cpy1, 3));
    }
    else if (tselect instanceof NodeType) {
        il.append(methodGen.loadDOM());
        _select.translate(classGen, methodGen);
        il.append(methodGen.loadHandler());
        il.append(new INVOKEINTERFACE(cpy2, 3));
    }
    else if (tselect instanceof ResultTreeType) {
        _select.translate(classGen, methodGen);
        // We want the whole tree, so we start with the root node
        il.append(DUP); //need a pointer to the DOM ;
        il.append(new INVOKEINTERFACE(getDoc,1)); //ICONST_0);
        il.append(methodGen.loadHandler());
        il.append(new INVOKEINTERFACE(cpy2, 3));
    }
    else if (tselect instanceof ReferenceType) {
        _select.translate(classGen, methodGen);
        il.append(methodGen.loadHandler());
        il.append(methodGen.loadCurrentNode());
        il.append(methodGen.loadDOM());
        final int copy = cpg.addMethodref(BASIS_LIBRARY_CLASS, "copy",
                                          "("
                                          + OBJECT_SIG
                                          + TRANSLET_OUTPUT_SIG
                                          + NODE_SIG
                                          + DOM_INTF_SIG
                                          + ")V");
        il.append(new INVOKESTATIC(copy));
    }
    else {
        il.append(classGen.loadTranslet());
        _select.translate(classGen, methodGen);
        il.append(methodGen.loadHandler());
        il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
                                                     CHARACTERSW,
                                                     CHARACTERSW_SIG)));
    }

}
 

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ResultTreeType; //导入依赖的package包/类
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    // Save current node and current iterator on the stack
    il.append(methodGen.loadCurrentNode());
    il.append(methodGen.loadIterator());

    // Collect sort objects associated with this instruction
    final Vector sortObjects = new Vector();
    Iterator<SyntaxTreeNode> children = elements();
    while (children.hasNext()) {
        final Object child = children.next();
        if (child instanceof Sort) {
            sortObjects.addElement(child);
        }
    }

    if ((_type != null) && (_type instanceof ResultTreeType)) {
        // Store existing DOM on stack - must be restored when loop is done
        il.append(methodGen.loadDOM());

        // <xsl:sort> cannot be applied to a result tree - issue warning
        if (sortObjects.size() > 0) {
            ErrorMsg msg = new ErrorMsg(ErrorMsg.RESULT_TREE_SORT_ERR,this);
            getParser().reportError(WARNING, msg);
        }

        // Put the result tree on the stack (DOM)
        _select.translate(classGen, methodGen);
        // Get an iterator for the whole DOM - excluding the root node
        _type.translateTo(classGen, methodGen, Type.NodeSet);
        // Store the result tree as the default DOM
        il.append(SWAP);
        il.append(methodGen.storeDOM());
    }
    else {
        // Compile node iterator
        if (sortObjects.size() > 0) {
            Sort.translateSortIterator(classGen, methodGen,
                                       _select, sortObjects);
        }
        else {
            _select.translate(classGen, methodGen);
        }

        if (_type instanceof ReferenceType == false) {
            il.append(methodGen.loadContextNode());
            il.append(methodGen.setStartNode());
        }
    }


    // Overwrite current iterator
    il.append(methodGen.storeIterator());

    // Give local variables (if any) default values before starting loop
    initializeVariables(classGen, methodGen);

    final BranchHandle nextNode = il.append(new GOTO(null));
    final InstructionHandle loop = il.append(NOP);

    translateContents(classGen, methodGen);

    nextNode.setTarget(il.append(methodGen.loadIterator()));
    il.append(methodGen.nextNode());
    il.append(DUP);
    il.append(methodGen.storeCurrentNode());
    il.append(new IFGT(loop));

    // Restore current DOM (if result tree was used instead for this loop)
    if ((_type != null) && (_type instanceof ResultTreeType)) {
        il.append(methodGen.storeDOM());
    }

    // Restore current node and current iterator from the stack
    il.append(methodGen.storeIterator());
    il.append(methodGen.storeCurrentNode());
}