/** 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;
}
/** Type check the two parameters for this function */
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
// Check that the function was passed exactly two arguments
if (argumentCount() != 2) {
throw new TypeCheckError(new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR, getName(), this));
}
// The first argument must be a literal String
Expression exp = argument(0);
if (exp instanceof LiteralExpr) {
_className = ((LiteralExpr) exp).getValue();
_type = Type.newObjectType(_className);
} else {
throw new TypeCheckError(new ErrorMsg(ErrorMsg.NEED_LITERAL_ERR, getName(), this));
}
// Second argument must be of type reference or object
_right = argument(1);
Type tright = _right.typeCheck(stable);
if (tright != Type.Reference && tright instanceof ObjectType == false) {
throw new TypeCheckError(new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR, tright, _type, this));
}
return _type;
}
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());
}
public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
final ConstantPoolGen cpg = classGen.getConstantPool();
final InstructionList il = methodGen.getInstructionList();
final Type tleft = _left.getType();
Type tright = _right.getType();
if (tleft instanceof BooleanType || tleft instanceof NumberType) {
translateDesynthesized(classGen, methodGen);
synthesize(classGen, methodGen);
return;
}
if (tleft instanceof StringType) {
final int equals = cpg.addMethodref(STRING_CLASS, "equals", "(" + OBJECT_SIG + ")Z");
_left.translate(classGen, methodGen);
_right.translate(classGen, methodGen);
il.append(new INVOKEVIRTUAL(equals));
if (_op == Operators.NE) {
il.append(ICONST_1);
il.append(IXOR); // not x <-> x xor 1
}
return;
}
BranchHandle truec, falsec;
if (tleft instanceof ResultTreeType) {
if (tright instanceof BooleanType) {
_right.translate(classGen, methodGen);
if (_op == Operators.NE) {
il.append(ICONST_1);
il.append(IXOR); // not x <-> x xor 1
}
return;
}
if (tright instanceof RealType) {
_left.translate(classGen, methodGen);
tleft.translateTo(classGen, methodGen, Type.Real);
_right.translate(classGen, methodGen);
il.append(DCMPG);
falsec =
il.append(
_op == Operators.EQ
? (BranchInstruction) new IFNE(null)
: (BranchInstruction) new IFEQ(null));
il.append(ICONST_1);
truec = il.append(new GOTO(null));
falsec.setTarget(il.append(ICONST_0));
truec.setTarget(il.append(NOP));
return;
}
// Next, result-tree/string and result-tree/result-tree comparisons
_left.translate(classGen, methodGen);
tleft.translateTo(classGen, methodGen, Type.String);
_right.translate(classGen, methodGen);
if (tright instanceof ResultTreeType) {
tright.translateTo(classGen, methodGen, Type.String);
}
final int equals = cpg.addMethodref(STRING_CLASS, "equals", "(" + OBJECT_SIG + ")Z");
il.append(new INVOKEVIRTUAL(equals));
if (_op == Operators.NE) {
il.append(ICONST_1);
il.append(IXOR); // not x <-> x xor 1
}
return;
}
if (tleft instanceof NodeSetType && tright instanceof BooleanType) {
_left.translate(classGen, methodGen);
_left.startIterator(classGen, methodGen);
Type.NodeSet.translateTo(classGen, methodGen, Type.Boolean);
_right.translate(classGen, methodGen);
il.append(IXOR); // x != y <-> x xor y
if (_op == Operators.EQ) {
il.append(ICONST_1);
il.append(IXOR); // not x <-> x xor 1
}
return;
}
if (tleft instanceof NodeSetType && tright instanceof StringType) {
_left.translate(classGen, methodGen);
_left.startIterator(classGen, methodGen); // needed ?
_right.translate(classGen, methodGen);
il.append(new PUSH(cpg, _op));
il.append(methodGen.loadDOM());
final int cmp =
cpg.addMethodref(
BASIS_LIBRARY_CLASS,
"compare",
"(" + tleft.toSignature() + tright.toSignature() + "I" + DOM_INTF_SIG + ")Z");
il.append(new INVOKESTATIC(cmp));
return;
}
// Next, node-set/t for t in {real, string, node-set, result-tree}
_left.translate(classGen, methodGen);
_left.startIterator(classGen, methodGen);
_right.translate(classGen, methodGen);
_right.startIterator(classGen, methodGen);
// Cast a result tree to a string to use an existing compare
if (tright instanceof ResultTreeType) {
tright.translateTo(classGen, methodGen, Type.String);
tright = Type.String;
}
// Call the appropriate compare() from the BasisLibrary
il.append(new PUSH(cpg, _op));
il.append(methodGen.loadDOM());
final int compare =
cpg.addMethodref(
BASIS_LIBRARY_CLASS,
"compare",
"(" + tleft.toSignature() + tright.toSignature() + "I" + DOM_INTF_SIG + ")Z");
il.append(new INVOKESTATIC(compare));
}