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1 package net.sf.saxon.instruct;
2 import net.sf.saxon.Configuration;
3 import net.sf.saxon.Controller;
4 import net.sf.saxon.expr.*;
5 import net.sf.saxon.om.AxisIterator;
6 import net.sf.saxon.om.SingletonIterator;
7 import net.sf.saxon.om.ValueRepresentation;
8 import net.sf.saxon.om.NamePool;
9 import net.sf.saxon.style.StandardNames;
10 import net.sf.saxon.trace.InstructionInfo;
11 import net.sf.saxon.trans.DynamicError;
12 import net.sf.saxon.trans.StaticError;
13 import net.sf.saxon.trans.XPathException;
14
15 import java.util.ArrayList  ;
16 import java.util.List ;
17 import java.util.Stack ;
18
19
22
23 public class GlobalVariable extends GeneralVariable implements Container {
24
25 private Executable executable;
26 private SlotManager stackFrameMap = null;
27
28 public Executable getExecutable() {
29 return executable;
30 }
31
32 public void setExecutable(Executable executable) {
33 this.executable = executable;
34 }
35
36 public void setContainsLocals(SlotManager map) {
37 this.stackFrameMap = map;
38 }
39
40 public boolean isGlobal() {
41 return true;
42 }
43
44
51
52 public void lookForCycles(Stack referees) throws StaticError {
53 if (referees.contains(this)) {
54 int s = referees.indexOf(this);
55 referees.push(this);
56 String message = "Circular definition of global variable. ";
57 NamePool pool = executable.getConfiguration().getNamePool();
58 for (int i=s; i<referees.size()-1; i++) {
59 if (referees.get(i+1) instanceof GlobalVariable) {
60 GlobalVariable next = (GlobalVariable)referees.get(i+1);
61 if (i==s) {
62 message += '$' + getVariableName() + " uses $" + next.getVariableName();
63 } else {
64 message += ", which uses $" + next.getVariableName();
65 }
66 } else if (referees.get(i+1) instanceof UserFunction) {
67 UserFunction next = (UserFunction)referees.get(i+1);
68 message += ", which calls " + pool.getDisplayName(next.getFunctionNameCode()) + "()";
69 }
70 }
71 message += '.';
72 StaticError err = new StaticError(message);
73 err.setErrorCode("XQST0054");
74 err.setLocator(this);
75 throw err;
76 }
77 if (select != null) {
78 referees.push(this);
79 List list = new ArrayList (10);
80 ExpressionTool.gatherReferencedVariables(select, list);
81 for (int i=0; i<list.size(); i++) {
82 Binding b = (Binding)list.get(i);
83 if (b instanceof GlobalVariable) {
84 ((GlobalVariable)b).lookForCycles(referees);
85 }
86 }
87 list.clear();
88 ExpressionTool.gatherCalledFunctions(select, list);
89 for (int i=0; i<list.size(); i++) {
90 UserFunction f = (UserFunction)list.get(i);
91 if (!referees.contains(f)) {
92 lookForFunctionCycles(f, referees);
94 }
95 }
96 referees.pop();
97 }
98 }
99
100
103
104 private static void lookForFunctionCycles(UserFunction f, Stack referees) throws StaticError {
105 Expression body = f.getBody();
106 referees.push(f);
107 List list = new ArrayList (10);
108 ExpressionTool.gatherReferencedVariables(body, list);
109 for (int i=0; i<list.size(); i++) {
110 Binding b = (Binding)list.get(i);
111 if (b instanceof GlobalVariable) {
112 ((GlobalVariable)b).lookForCycles(referees);
113 }
114 }
115 list.clear();
116 ExpressionTool.gatherCalledFunctions(body, list);
117 for (int i=0; i<list.size(); i++) {
118 UserFunction fn = (UserFunction)list.get(i);
119 if (!referees.contains(fn)) {
120 lookForFunctionCycles(fn, referees);
122 }
123 }
124 referees.pop();
125 }
126
127
128
131
132 public TailCall processLeavingTail(XPathContext context) throws XPathException {
133
134 return null;
137 }
138
139
144
145 public ValueRepresentation getSelectValue(XPathContext context) throws XPathException {
146 if (select==null) {
147 throw new AssertionError ("*** No select expression for global variable!!");
148 } else {
149 XPathContextMajor c2 = context.newCleanContext();
150 c2.setOrigin(this);
151 AxisIterator initialNode = SingletonIterator.makeIterator(c2.getController().getPrincipalSourceDocument());
152 initialNode.next();
153 c2.setCurrentIterator(initialNode);
154 if (stackFrameMap != null) {
155 c2.openStackFrame(stackFrameMap);
156 }
157 return ExpressionTool.lazyEvaluate(select, c2, 10);
158 }
159 }
160
161
164
165 public ValueRepresentation evaluateVariable(XPathContext context) throws XPathException {
166 Controller controller = context.getController();
167 Bindery b = controller.getBindery();
168
169 ValueRepresentation v = b.getGlobalVariableValue(this);
170
171 if (v != null) {
172 return v;
173 } else {
174
175
179 try {
180 b.setExecuting(this, true);
181 ValueRepresentation value = getSelectValue(context);
182 b.defineGlobalVariable(this, value);
183 b.setExecuting(this, false);
184 return value;
185
186 } catch (XPathException err) {
187 b.setExecuting(this, false);
188 if (err instanceof XPathException.Circularity) {
189 DynamicError e = new DynamicError("Circular definition of variable " + getVariableName());
190 int lang = context.getController().getExecutable().getHostLanguage();
191 e.setErrorCode(lang == Configuration.XQUERY ? "XQST0054" : "XTDE0640");
192 e.setXPathContext(context);
193 select = new ErrorExpression(e);
195 throw e;
196 } else {
197 throw err;
198 }
199 }
200 }
201 }
202
203
206
207 public InstructionInfo getInstructionInfo() {
208 InstructionDetails details = new InstructionDetails();
209 details.setConstructType(StandardNames.XSL_VARIABLE);
210 details.setObjectNameCode(getVariableFingerprint());
211 details.setProperty("expression", this);
212 details.setSystemId(getSystemId());
213 details.setLineNumber(getLineNumber());
214 details.setColumnNumber(getColumnNumber());
215 return details;
216 }
217
218
219 }
220
221 |
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