1/*
2 * Copyright (c) 1994, 2003, Oracle and/or its affiliates. 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.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * 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<Object, Object> 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}
217