/*
* 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
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*/
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(";");
}
}
}