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1
24
25 package org.aspectj.compiler.base.ast;
26
27 import org.aspectj.compiler.base.*;
28 import org.aspectj.compiler.base.JavaCompiler;
29 import org.aspectj.compiler.base.CodeWriter;
30
31 import org.aspectj.compiler.base.bcg.CodeBuilder;
32 import org.aspectj.compiler.base.bcg.Label;
33
34
39
40 public class WhileStmt extends TestStmt {
41
42 public boolean isBreakable() { return true; }
43 public boolean isContinuable() { return true; }
44
45 public void unparse(CodeWriter writer) {
46 writer.writeKeyword("while");
47 writer.optionalSpace();
48 writer.parenExpr(test);
49 writer.write(body);
50 }
51
52 public void checkSpec() {
53 body.requireStmt();
54 super.checkSpec();
55 }
56
57
60 public void walkFlow(FlowCheckerPass w) {
61 FlowCheckerPass.Set enteringPossiblyAssigned = w.popPossiblyAssigned();
63 w.processBoolean(getTest());
64 FlowCheckerPass.Vars p = w.getVars();
65 FlowCheckerPass.Vars tv = p.getTrue();
66 FlowCheckerPass.Vars fv = p.getFalse();
67
68 w.setLive(! getTest().isConstantFalse());
69 w.setVars(tv);
70 w.enterContext(this);
71 w.process(getBody());
72 w.leaveContext();
73
74 FlowCheckerPass.Vars v = w.getVars();
75 FlowCheckerPass.Vars cv = w.getContinueVars(this);
76 FlowCheckerPass.Vars bv = w.getBreakVars(this);
77
78 FlowCheckerPass.Set loopPossiblyAssigned = w.popPossiblyAssigned();
79
80 w.checkLoopingFinals(this, loopPossiblyAssigned.inter(enteringPossiblyAssigned), v.join(cv));
81 w.mergePossiblyAssigned(enteringPossiblyAssigned);
82 w.mergePossiblyAssigned(loopPossiblyAssigned);
83
84 w.setLive(! getTest().isConstantTrue() || w.isBroken(this));
85 w.setVars(fv.join(bv));
86 }
87
88
91 public void walkCleanup(ByteCodeCleanupPass w) {
92 if (getTest().isConstantFalse()) return;
93 w.enterContext(this);
94 w.process(getBody());
95 w.leaveContext();
96 w.setLive(! getTest().isConstantTrue() || w.isBroken(this));
97 }
98
99 public ASTObject postCleanup(ByteCodeCleanupPass w) {
100 if (getTest().isConstantFalse()) {
101 return getAST().makeEmptyStmt().setSource(this);
102 } else {
103 return this;
104 }
105 }
106
107
110 protected void cgStmt(CodeBuilder cb) {
111 Label startLab = cb.genLabel();
112 Label testLab = cb.genLabel();
113 Label endLab = cb.genLabel();
114 cb.emitJump(testLab);
115 cb.emitLabel(startLab);
116 cb.enterNonWindingContext(this, endLab, testLab);
117 body.cgTop(cb);
118 cb.leaveContext();
119 cb.emitLabel(testLab);
120 test.cgTest(cb, startLab, endLab);
121 cb.emitLabel(endLab);
122 }
123
124 protected Expr test;
126 public Expr getTest() { return test; }
127 public void setTest(Expr _test) {
128 if (_test != null) _test.setParent(this);
129 test = _test;
130 }
131
132 protected Stmt body;
133 public Stmt getBody() { return body; }
134 public void setBody(Stmt _body) {
135 if (_body != null) _body.setParent(this);
136 body = _body;
137 }
138
139 public WhileStmt(SourceLocation location, Expr _test, Stmt _body) {
140 super(location);
141 setTest(_test);
142 setBody(_body);
143 }
144 protected WhileStmt(SourceLocation source) {
145 super(source);
146 }
147
148 public ASTObject copyWalk(CopyWalker walker) {
149 WhileStmt ret = new WhileStmt(getSourceLocation());
150 ret.preCopy(walker, this);
151 if (test != null) ret.setTest( (Expr)walker.process(test) );
152 if (body != null) ret.setBody( (Stmt)walker.process(body) );
153 return ret;
154 }
155
156 public ASTObject getChildAt(int childIndex) {
157 switch(childIndex) {
158 case 0: return test;
159 case 1: return body;
160 default: return super.getChildAt(childIndex);
161 }
162 }
163 public String  getChildNameAt(int childIndex) {
164 switch(childIndex) {
165 case 0: return "test";
166 case 1: return "body";
167 default: return super.getChildNameAt(childIndex);
168 }
169 }
170 public void setChildAt(int childIndex, ASTObject child) {
171 switch(childIndex) {
172 case 0: setTest((Expr)child); return;
173 case 1: setBody((Stmt)child); return;
174 default: super.setChildAt(childIndex, child); return;
175 }
176 }
177 public int getChildCount() {
178 return 2;
179 }
180
181 public String getDefaultDisplayName() {
182 return "WhileStmt()";
183 }
184
185 }
187 |
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