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J. Duke319a3b92007-12-01 00:00:00 +00001/*
2 * Copyright 1994-2003 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26package sun.tools.tree;
27
28import sun.tools.java.*;
29import sun.tools.asm.Assembler;
30import sun.tools.asm.Label;
31import java.io.PrintStream;
32import java.util.Hashtable;
33
34/**
35 * WARNING: The contents of this source file are not part of any
36 * supported API. Code that depends on them does so at its own risk:
37 * they are subject to change or removal without notice.
38 */
39public
40class ForStatement extends Statement {
41 Statement init;
42 Expression cond;
43 Expression inc;
44 Statement body;
45
46 /**
47 * Constructor
48 */
49 public ForStatement(long where, Statement init, Expression cond, Expression inc, Statement body) {
50 super(FOR, where);
51 this.init = init;
52 this.cond = cond;
53 this.inc = inc;
54 this.body = body;
55 }
56
57 /**
58 * Check statement
59 */
60 Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {
61 checkLabel(env, ctx);
62 vset = reach(env, vset);
63 Context initctx = new Context(ctx, this);
64 if (init != null) {
65 vset = init.checkBlockStatement(env, initctx, vset, exp);
66 }
67 CheckContext newctx = new CheckContext(initctx, this);
68 // remember what was unassigned on entry
69 Vset vsEntry = vset.copy();
70 ConditionVars cvars;
71 if (cond != null) {
72 cvars = cond.checkCondition(env, newctx, vset, exp);
73 cond = convert(env, newctx, Type.tBoolean, cond);
74 } else {
75 // a missing test is equivalent to "true"
76 cvars = new ConditionVars();
77 cvars.vsFalse = Vset.DEAD_END;
78 cvars.vsTrue = vset;
79 }
80 vset = body.check(env, newctx, cvars.vsTrue, exp);
81 vset = vset.join(newctx.vsContinue);
82 if (inc != null) {
83 vset = inc.check(env, newctx, vset, exp);
84 }
85 // Make sure the back-branch fits the entry of the loop.
86 // Must include variables declared in the for-init part in the
87 // set of variables visible upon loop entry that must be checked.
88 initctx.checkBackBranch(env, this, vsEntry, vset);
89 // exit by testing false or executing a break;
90 vset = newctx.vsBreak.join(cvars.vsFalse);
91 return ctx.removeAdditionalVars(vset);
92 }
93
94 /**
95 * Inline
96 */
97 public Statement inline(Environment env, Context ctx) {
98 ctx = new Context(ctx, this);
99 if (init != null) {
100 Statement body[] = {init, this};
101 init = null;
102 return new CompoundStatement(where, body).inline(env, ctx);
103 }
104 if (cond != null) {
105 cond = cond.inlineValue(env, ctx);
106 }
107 if (body != null) {
108 body = body.inline(env, ctx);
109 }
110 if (inc != null) {
111 inc = inc.inline(env, ctx);
112 }
113 return this;
114 }
115
116 /**
117 * Create a copy of the statement for method inlining
118 */
119 public Statement copyInline(Context ctx, boolean valNeeded) {
120 ForStatement s = (ForStatement)clone();
121 if (init != null) {
122 s.init = init.copyInline(ctx, valNeeded);
123 }
124 if (cond != null) {
125 s.cond = cond.copyInline(ctx);
126 }
127 if (body != null) {
128 s.body = body.copyInline(ctx, valNeeded);
129 }
130 if (inc != null) {
131 s.inc = inc.copyInline(ctx);
132 }
133 return s;
134 }
135
136 /**
137 * The cost of inlining this statement
138 */
139 public int costInline(int thresh, Environment env, Context ctx) {
140 int cost = 2;
141 if (init != null) {
142 cost += init.costInline(thresh, env, ctx);
143 }
144 if (cond != null) {
145 cost += cond.costInline(thresh, env, ctx);
146 }
147 if (body != null) {
148 cost += body.costInline(thresh, env, ctx);
149 }
150 if (inc != null) {
151 cost += inc.costInline(thresh, env, ctx);
152 }
153 return cost;
154 }
155
156 /**
157 * Code
158 */
159 public void code(Environment env, Context ctx, Assembler asm) {
160 CodeContext newctx = new CodeContext(ctx, this);
161 if (init != null) {
162 init.code(env, newctx, asm);
163 }
164
165 Label l1 = new Label();
166 Label l2 = new Label();
167
168 asm.add(where, opc_goto, l2);
169
170 asm.add(l1);
171 if (body != null) {
172 body.code(env, newctx, asm);
173 }
174
175 asm.add(newctx.contLabel);
176 if (inc != null) {
177 inc.code(env, newctx, asm);
178 }
179
180 asm.add(l2);
181 if (cond != null) {
182 cond.codeBranch(env, newctx, asm, l1, true);
183 } else {
184 asm.add(where, opc_goto, l1);
185 }
186 asm.add(newctx.breakLabel);
187 }
188
189 /**
190 * Print
191 */
192 public void print(PrintStream out, int indent) {
193 super.print(out, indent);
194 out.print("for (");
195 if (init != null) {
196 init.print(out, indent);
197 out.print(" ");
198 } else {
199 out.print("; ");
200 }
201 if (cond != null) {
202 cond.print(out);
203 out.print(" ");
204 }
205 out.print("; ");
206 if (inc != null) {
207 inc.print(out);
208 }
209 out.print(") ");
210 if (body != null) {
211 body.print(out, indent);
212 } else {
213 out.print(";");
214 }
215 }
216}