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1
24
25 package org.aspectj.compiler.base.ast;
26
27 import org.aspectj.compiler.base.*;
28 import java.util.*;
29
30 import org.aspectj.compiler.base.JavaCompiler;
31 import org.aspectj.compiler.base.CodeWriter;
32
33 import org.aspectj.compiler.base.bcg.CodeBuilder;
34 import org.aspectj.compiler.base.bcg.Label;
35
36 import java.util.Iterator  ;
37
38
43 public class TryCatchStmt extends TryStmt {
44
45 public void checkSpec() {
46 super.checkSpec();
47 if (catches.size() == 0) {
48 showError("'try' without 'catch' or 'finally'");
49 }
50
51 body.requireBlockStmt();
52 }
53
54 public void unparse(CodeWriter writer) {
55 if (catches.size() == 0) {
56 writer.write(body);
57 return;
58 }
59
60 writer.writeKeyword("try");
61 writer.optionalSpace();
62 writer.write(body);
63
64 writer.writeChildren(catches);
65 }
66
67 public ASTObject postFixAST(final ASTFixerPass fixer) {
70 if (! isOptional()) return super.postFixAST(fixer);
71
72 Set exceptions = ExceptionFinder.getPossibleExceptions(getBody(), true);
74
75
78 exceptions.add(getTypeManager().getRuntimeExceptionType());
79 exceptions.add(getTypeManager().getErrorType());
80
82 filterCatchClauses(catches, exceptions);
83 setIsOptional(false);
84 return super.postFixAST(fixer);
85 }
86 private void filterCatchClauses(CatchClauses ccs, Set exceptions) {
87 for (int i = 0; i < ccs.size(); i++) {
89 CatchClause cc = ccs.get(i);
90 if (!possibleCatchClause(cc, exceptions)) {
92 ccs.remove(i);
94 i--;
95 }
96 }
97 }
98 private boolean possibleCatchClause(CatchClause cc, Set exceptions) {
99 return canThrow(exceptions, cc.getFormal().getType());
100 }
101 private boolean canThrow(Set types, Type baseType) {
103
107 for(Iterator iter = types.iterator(); iter.hasNext(); ) {
108 Type checkType = (Type)iter.next();
109 if (checkType != null && (checkType.isSubtypeOf(baseType) ||
110 baseType.isSubtypeOf(checkType))) {
111 return true;
112 }
113 }
114 return false;
115 }
116
117
120 public void walkFlow(FlowCheckerPass w) {
121 FlowCheckerPass.Vars beforeV = w.getVars();
122 FlowCheckerPass.ESet beforeExns = w.popExns();
123 w.enterContext(this);
124 w.process(getBody());
125 w.leaveContext();
126 boolean bodyLive = w.isLive();
127 FlowCheckerPass.ESet bodyExns = w.popExns();
128
129 FlowCheckerPass.Vars v = w.getVars(); FlowCheckerPass.Vars tv = w.getTryVars(this);
132 FlowCheckerPass.Vars cv =
133 FlowCheckerPass.Vars.makeSets(beforeV.getDa(),
134 v.getDua().inter(tv.getDua()));
135
136 FlowCheckerPass.ESet caughtExns = FlowCheckerPass.ESet.getEmpty();
137 FlowCheckerPass.ESet thrownExns = beforeExns;
138 FlowCheckerPass.Vars cvExit = v;
139 boolean liveSoFar = bodyLive;
140 CatchClauses c = getCatches();
141 if (c != null) {
142 for (int i = 0, len = c.size(); i < len; i++) {
143 CatchClause cl = c.get(i);
144 NameType exnType = (NameType) cl.getFormal().getType();
145 if (! bodyExns.containsSuperOrSub(exnType) &&
146 ! exnType.isUncheckedThrowable() &&
147 exnType != getTypeManager().getExceptionType() &&
148 exnType != getTypeManager().getThrowableType()) {
149 cl.showError("exception " + exnType.getId() +
150 " is never thrown in body of corresponding try statement");
151 continue;
152 }
153 if (caughtExns.containsSuper(exnType)) {
154 cl.showError("exception " + exnType.getId() + " has already been caught");
155 continue;
156 }
157 w.setLive(true);
158 w.setVars(cv);
159 w.enterContext(this);
166 w.process(cl);
167 w.leaveContext();
168 liveSoFar = liveSoFar | w.isLive();
169 cvExit = cvExit.join(w.getVars());
170 thrownExns = thrownExns.union(w.popExns());
171 caughtExns = caughtExns.add(exnType);
172 }
173 }
174 w.setExns(bodyExns.diff(caughtExns).union(thrownExns).union(beforeExns));
175 w.setVars(cvExit);
176 w.releasePendingTransfers(this);
177 w.setLive(liveSoFar);
178 }
179
180
183 public void walkCleanup(ByteCodeCleanupPass w) {
184 w.enterContext(this);
185 setBody((Stmt) w.process(getBody()));
186 w.leaveContext();
187 boolean bodyLive = w.isLive();
188
189 boolean liveSoFar = bodyLive;
190 CatchClauses c = getCatches();
191 for (int i = 0, len = c.size(); i < len; i++) {
192 CatchClause cl = c.get(i);
193 w.setLive(true);
194 w.process(cl);
195 liveSoFar = liveSoFar || w.isLive();
196 }
197 w.setLive(liveSoFar);
198 }
199
200 public ASTObject postCleanup(ByteCodeCleanupPass walker) {
201 if (getBody() instanceof EmptyStmt) {
202 return getAST().makeEmptyStmt().setSource(this);
203 } else {
204 return this;
205 }
206 }
207
208
211 protected void cgStmt(CodeBuilder cb) {
212 Label startBody = cb.genAnchor();
213 Label endBody = cb.genAnchor();
214 Label end = cb.genLabel();
215 cb.emitLabel(startBody);
216 getBody().cgTop(cb);
217 cb.emitLabel(endBody);
218 if (body.completesNormally()) cb.emitJump(end);
219 for (int i = 0, len = catches.size(); i < len; i++ ) {
220 CatchClause clause = catches.get(i);
221 Label exnStart = cb.genAnchor();
222 FormalDec clauseFormal = clause.getFormal();
223 Stmt clauseBody = clause.getBody();
224
225 cb.enterBlock();
226 cb.enterVar(clauseFormal);
227 cb.emitLabel(exnStart);
228 cb.pushStack(1); cb.emitASTORE(clauseFormal.getFrameLoc()); clauseBody.cgTop(cb);
231 if (clauseBody.completesNormally()) cb.emitJump(end);
232 cb.addHandler(startBody, endBody, exnStart, (NameType) clauseFormal.getType());
233 cb.exitBlock();
234 }
235 cb.emitLabel(end);
236 }
237
238 protected Stmt body;
240 public Stmt getBody() { return body; }
241 public void setBody(Stmt _body) {
242 if (_body != null) _body.setParent(this);
243 body = _body;
244 }
245
246 protected CatchClauses catches;
247 public CatchClauses getCatches() { return catches; }
248 public void setCatches(CatchClauses _catches) {
249 if (_catches != null) _catches.setParent(this);
250 catches = _catches;
251 }
252
253 public TryCatchStmt(SourceLocation location, Stmt _body, CatchClauses _catches) {
254 super(location);
255 setBody(_body);
256 setCatches(_catches);
257 }
258 protected TryCatchStmt(SourceLocation source) {
259 super(source);
260 }
261
262 public ASTObject copyWalk(CopyWalker walker) {
263 TryCatchStmt ret = new TryCatchStmt(getSourceLocation());
264 ret.preCopy(walker, this);
265 if (body != null) ret.setBody( (Stmt)walker.process(body) );
266 if (catches != null) ret.setCatches( (CatchClauses)walker.process(catches) );
267 return ret;
268 }
269
270 public ASTObject getChildAt(int childIndex) {
271 switch(childIndex) {
272 case 0: return body;
273 case 1: return catches;
274 default: return super.getChildAt(childIndex);
275 }
276 }
277 public String getChildNameAt(int childIndex) {
278 switch(childIndex) {
279 case 0: return "body";
280 case 1: return "catches";
281 default: return super.getChildNameAt(childIndex);
282 }
283 }
284 public void setChildAt(int childIndex, ASTObject child) {
285 switch(childIndex) {
286 case 0: setBody((Stmt)child); return;
287 case 1: setCatches((CatchClauses)child); return;
288 default: super.setChildAt(childIndex, child); return;
289 }
290 }
291 public int getChildCount() {
292 return 2;
293 }
294
295 public String getDefaultDisplayName() {
296 return "TryCatchStmt()";
297 }
298
299 }
301
302
303 |
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