assign.c

早期freebsd实现

/*-
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)assign.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

/*
 * assign the value of an expression to a variable (or term)
 */

#include "defs.h"
#include "tree.h"
#include "sym.h"
#include "process.h"
#include "tree.rep"
#include "process/process.rep"
#include "process/pxinfo.h"

assign(var, exp)
NODE *var;
NODE *exp;
{
	ADDRESS addr;
	int varsize;
	char cvalue;
	short svalue;
	long lvalue;

	if (!compatible(var->nodetype, exp->nodetype)) {
		error("incompatible types");
	}
	addr = lval(var);
	eval(exp);
	varsize = size(var->nodetype);
	if (varsize < sizeof(long)) {
		lvalue = pop(long);
		switch (varsize) {
			case sizeof(char):
				cvalue = lvalue;
				dwrite(&cvalue, addr, varsize);
				break;

			case sizeof(short):
				svalue = lvalue;
				dwrite(&svalue, addr, varsize);
				break;

			default:
				goto othersize;
				/*
				panic("bad size %d", varsize);
				*/
		}
	} else {
	    othersize:
		sp -= varsize;
		dwrite(sp, addr, varsize);
#ifdef tahoe
		downalignstack();
#endif
	}
}