| /* |
| * Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.tools.tree; |
| |
| import sun.tools.java.*; |
| import sun.tools.asm.Assembler; |
| import sun.tools.asm.Label; |
| import java.io.PrintStream; |
| import java.util.Hashtable; |
| |
| /** |
| * WARNING: The contents of this source file are not part of any |
| * supported API. Code that depends on them does so at its own risk: |
| * they are subject to change or removal without notice. |
| */ |
| public |
| class WhileStatement extends Statement { |
| Expression cond; |
| Statement body; |
| |
| /** |
| * Constructor |
| */ |
| public WhileStatement(long where, Expression cond, Statement body) { |
| super(WHILE, where); |
| this.cond = cond; |
| this.body = body; |
| } |
| |
| /** |
| * Check a while statement |
| */ |
| Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) { |
| checkLabel(env, ctx); |
| CheckContext newctx = new CheckContext(ctx, this); |
| // remember what was unassigned on entry |
| Vset vsEntry = vset.copy(); |
| // check the condition. Determine which variables have values if |
| // it returns true or false. |
| ConditionVars cvars = |
| cond.checkCondition(env, newctx, reach(env, vset), exp); |
| cond = convert(env, newctx, Type.tBoolean, cond); |
| // check the body, given that the condition returned true. |
| vset = body.check(env, newctx, cvars.vsTrue, exp); |
| vset = vset.join(newctx.vsContinue); |
| // make sure the back-branch fits the entry of the loop |
| ctx.checkBackBranch(env, this, vsEntry, vset); |
| // Exit the while loop by testing false or getting a break statement |
| vset = newctx.vsBreak.join(cvars.vsFalse); |
| return ctx.removeAdditionalVars(vset); |
| } |
| |
| /** |
| * Inline |
| */ |
| public Statement inline(Environment env, Context ctx) { |
| ctx = new Context(ctx, this); |
| cond = cond.inlineValue(env, ctx); |
| if (body != null) { |
| body = body.inline(env, ctx); |
| } |
| return this; |
| } |
| |
| /** |
| * The cost of inlining this statement |
| */ |
| public int costInline(int thresh, Environment env, Context ctx) { |
| return 1 + cond.costInline(thresh, env, ctx) |
| + ((body != null) ? body.costInline(thresh, env, ctx) : 0); |
| } |
| |
| /** |
| * Create a copy of the statement for method inlining |
| */ |
| public Statement copyInline(Context ctx, boolean valNeeded) { |
| WhileStatement s = (WhileStatement)clone(); |
| s.cond = cond.copyInline(ctx); |
| if (body != null) { |
| s.body = body.copyInline(ctx, valNeeded); |
| } |
| return s; |
| } |
| |
| /** |
| * Code |
| */ |
| public void code(Environment env, Context ctx, Assembler asm) { |
| CodeContext newctx = new CodeContext(ctx, this); |
| |
| asm.add(where, opc_goto, newctx.contLabel); |
| |
| Label l1 = new Label(); |
| asm.add(l1); |
| |
| if (body != null) { |
| body.code(env, newctx, asm); |
| } |
| |
| asm.add(newctx.contLabel); |
| cond.codeBranch(env, newctx, asm, l1, true); |
| asm.add(newctx.breakLabel); |
| } |
| |
| /** |
| * Print |
| */ |
| public void print(PrintStream out, int indent) { |
| super.print(out, indent); |
| out.print("while "); |
| cond.print(out); |
| if (body != null) { |
| out.print(" "); |
| body.print(out, indent); |
| } else { |
| out.print(";"); |
| } |
| } |
| } |