/*
* @(#)WhileStatement.java 1.15 95/11/12 Arthur van Hoff
*
* Copyright (c) 1994 Sun Microsystems, Inc. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software
* and its documentation for NON-COMMERCIAL purposes and without
* fee is hereby granted provided that this copyright notice
* appears in all copies. Please refer to the file "copyright.html"
* for further important copyright and licensing information.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
* THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
* TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
*/
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;
public
class WhileStatement extends Statement {
Expression cond;
Statement body;
/**
* Constructor
*/
public WhileStatement(int where, Expression cond, Statement body) {
super(WHILE, where);
this.cond = cond;
this.body = body;
}
/**
* Check a while statement
*/
long check(Environment env, Context ctx, long vset, Hashtable exp) {
CheckContext newctx = new CheckContext(ctx, this);
// 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.
body.check(env, newctx, cvars.vsTrue, exp);
// Exit the while loop by testing false or getting a break statement
vset = newctx.vsBreak & 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) {
return 1 + cond.costInline(thresh) + ((body != null) ? body.costInline(thresh) : 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(";");
}
}
}