--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jaxp/src/com/sun/org/apache/xalan/internal/xsltc/compiler/Expression.java Thu Apr 12 08:38:26 2012 -0700
@@ -0,0 +1,224 @@
+/*
+ * reserved comment block
+ * DO NOT REMOVE OR ALTER!
+ */
+/*
+ * Copyright 2001-2004 The Apache Software Foundation.
+ *
+ * Licensed 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: Expression.java,v 1.2.4.1 2005/09/01 14:17:51 pvedula Exp $
+ */
+
+package com.sun.org.apache.xalan.internal.xsltc.compiler;
+
+import java.util.Vector;
+
+import com.sun.org.apache.bcel.internal.generic.BranchHandle;
+import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
+import com.sun.org.apache.bcel.internal.generic.GOTO_W;
+import com.sun.org.apache.bcel.internal.generic.IFEQ;
+import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
+import com.sun.org.apache.bcel.internal.generic.InstructionList;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodType;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeSetType;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
+import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
+
+/**
+ * @author Jacek Ambroziak
+ * @author Santiago Pericas-Geertsen
+ * @author Morten Jorgensen
+ * @author Erwin Bolwidt <ejb@klomp.org>
+ */
+abstract class Expression extends SyntaxTreeNode {
+ /**
+ * The type of this expression. It is set after calling
+ * <code>typeCheck()</code>.
+ */
+ protected Type _type;
+
+ /**
+ * Instruction handles that comprise the true list.
+ */
+ protected FlowList _trueList = new FlowList();
+
+ /**
+ * Instruction handles that comprise the false list.
+ */
+ protected FlowList _falseList = new FlowList();
+
+ public Type getType() {
+ return _type;
+ }
+
+ public abstract String toString();
+
+ public boolean hasPositionCall() {
+ return false; // default should be 'false' for StepPattern
+ }
+
+ public boolean hasLastCall() {
+ return false;
+ }
+
+ /**
+ * Returns an object representing the compile-time evaluation
+ * of an expression. We are only using this for function-available
+ * and element-available at this time.
+ */
+ public Object evaluateAtCompileTime() {
+ return null;
+ }
+
+ /**
+ * Type check all the children of this node.
+ */
+ public Type typeCheck(SymbolTable stable) throws TypeCheckError {
+ return typeCheckContents(stable);
+ }
+
+ /**
+ * Translate this node into JVM bytecodes.
+ */
+ public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
+ ErrorMsg msg = new ErrorMsg(ErrorMsg.NOT_IMPLEMENTED_ERR,
+ getClass(), this);
+ getParser().reportError(FATAL, msg);
+ }
+
+ /**
+ * Translate this node into a fresh instruction list.
+ * The original instruction list is saved and restored.
+ */
+ public final InstructionList compile(ClassGenerator classGen,
+ MethodGenerator methodGen) {
+ final InstructionList result, save = methodGen.getInstructionList();
+ methodGen.setInstructionList(result = new InstructionList());
+ translate(classGen, methodGen);
+ methodGen.setInstructionList(save);
+ return result;
+ }
+
+ /**
+ * Redefined by expressions of type boolean that use flow lists.
+ */
+ public void translateDesynthesized(ClassGenerator classGen,
+ MethodGenerator methodGen) {
+ translate(classGen, methodGen);
+ if (_type instanceof BooleanType) {
+ desynthesize(classGen, methodGen);
+ }
+ }
+
+ /**
+ * If this expression is of type node-set and it is not a variable
+ * reference, then call setStartNode() passing the context node.
+ */
+ public void startIterator(ClassGenerator classGen,
+ MethodGenerator methodGen) {
+ // Ignore if type is not node-set
+ if (_type instanceof NodeSetType == false) {
+ return;
+ }
+
+ // setStartNode() should not be called if expr is a variable ref
+ Expression expr = this;
+ if (expr instanceof CastExpr) {
+ expr = ((CastExpr) expr).getExpr();
+ }
+ if (expr instanceof VariableRefBase == false) {
+ final InstructionList il = methodGen.getInstructionList();
+ il.append(methodGen.loadContextNode());
+ il.append(methodGen.setStartNode());
+ }
+ }
+
+ /**
+ * Synthesize a boolean expression, i.e., either push a 0 or 1 onto the
+ * operand stack for the next statement to succeed. Returns the handle
+ * of the instruction to be backpatched.
+ */
+ public void synthesize(ClassGenerator classGen, MethodGenerator methodGen) {
+ final ConstantPoolGen cpg = classGen.getConstantPool();
+ final InstructionList il = methodGen.getInstructionList();
+ _trueList.backPatch(il.append(ICONST_1));
+ final BranchHandle truec = il.append(new GOTO_W(null));
+ _falseList.backPatch(il.append(ICONST_0));
+ truec.setTarget(il.append(NOP));
+ }
+
+ public void desynthesize(ClassGenerator classGen,
+ MethodGenerator methodGen) {
+ final InstructionList il = methodGen.getInstructionList();
+ _falseList.add(il.append(new IFEQ(null)));
+ }
+
+ public FlowList getFalseList() {
+ return _falseList;
+ }
+
+ public FlowList getTrueList() {
+ return _trueList;
+ }
+
+ public void backPatchFalseList(InstructionHandle ih) {
+ _falseList.backPatch(ih);
+ }
+
+ public void backPatchTrueList(InstructionHandle ih) {
+ _trueList.backPatch(ih);
+ }
+
+ /**
+ * Search for a primop in the symbol table that matches the method type
+ * <code>ctype</code>. Two methods match if they have the same arity.
+ * If a primop is overloaded then the "closest match" is returned. The
+ * first entry in the vector of primops that has the right arity is
+ * considered to be the default one.
+ */
+ public MethodType lookupPrimop(SymbolTable stable, String op,
+ MethodType ctype) {
+ MethodType result = null;
+ final Vector primop = stable.lookupPrimop(op);
+ if (primop != null) {
+ final int n = primop.size();
+ int minDistance = Integer.MAX_VALUE;
+ for (int i = 0; i < n; i++) {
+ final MethodType ptype = (MethodType) primop.elementAt(i);
+ // Skip if different arity
+ if (ptype.argsCount() != ctype.argsCount()) {
+ continue;
+ }
+
+ // The first method with the right arity is the default
+ if (result == null) {
+ result = ptype; // default method
+ }
+
+ // Check if better than last one found
+ final int distance = ctype.distanceTo(ptype);
+ if (distance < minDistance) {
+ minDistance = distance;
+ result = ptype;
+ }
+ }
+ }
+ return result;
+ }
+}