rval.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[] = "@(#)rval.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#include "whoami.h"
#include "0.h"
#include "tree.h"
#include "opcode.h"
#include "objfmt.h"
#ifdef PC
#   include	"pc.h"
#   include <pcc.h>
#endif PC
#include "tmps.h"
#include "tree_ty.h"

extern	char *opnames[];

    /* line number of the last record comparison warning */
short reccompline = 0;
    /* line number of the last non-standard set comparison */
short nssetline = 0;

#ifdef PC
    char	*relts[] =  {
				"_RELEQ" , "_RELNE" ,
				"_RELTLT" , "_RELTGT" ,
				"_RELTLE" , "_RELTGE"
			    };
    char	*relss[] =  {
				"_RELEQ" , "_RELNE" ,
				"_RELSLT" , "_RELSGT" ,
				"_RELSLE" , "_RELSGE"
			    };
    long	relops[] =  {	
				PCC_EQ , PCC_NE ,
				PCC_LT , PCC_GT ,
				PCC_LE , PCC_GE 
			    };
    long	mathop[] =  {	PCC_MUL , PCC_PLUS , PCC_MINUS };
    char	*setop[] =  {	"_MULT" , "_ADDT" , "_SUBT" };
#endif PC
/*
 * Rvalue - an expression.
 *
 * Contype is the type that the caller would prefer, nand is important
 * if constant strings are involved, because of string padding.
 * required is a flag whether an lvalue or an rvalue is required.
 * only VARs and structured things can have gt their lvalue this way.
 */
/*ARGSUSED*/
struct nl *
rvalue(r, contype , required )
	struct tnode *r;
	struct nl *contype;
	int	required;
{
	register struct nl *p, *p1;
	register struct nl *q;
	int c, c1, w;
#ifdef OBJ
	int g;
#endif
	struct tnode *rt;
	char *cp, *cp1, *opname;
	long l;
	union
	{
	    long plong[2];
	    double pdouble;
	}f;
	extern int	flagwas;
	struct csetstr	csetd;
#	ifdef PC
	    struct nl	*rettype;
	    long	ctype;
	    struct nl	*tempnlp;
#	endif PC

	if (r == TR_NIL)
		return (NLNIL);
	if (nowexp(r))
		return (NLNIL);
	/*
	 * Pick up the name of the operation
	 * for future error messages.
	 */
	if (r->tag <= T_IN)
		opname = opnames[r->tag];

	/*
	 * The root of the tree tells us what sort of expression we have.
	 */
	switch (r->tag) {

	/*
	 * The constant nil
	 */
	case T_NIL:
#		ifdef OBJ
		    (void) put(2, O_CON2, 0);
#		endif OBJ
#		ifdef PC
		    putleaf( PCC_ICON , 0 , 0 , PCCTM_PTR|PCCT_UNDEF , (char *) 0 );
#		endif PC
		return (nl+TNIL);

	/*
	 * Function call with arguments.
	 */
	case T_FCALL:
#	    ifdef OBJ
		return (funccod(r));
#	    endif OBJ
#	    ifdef PC
		return (pcfunccod( r ));
#	    endif PC

	case T_VAR:
		p = lookup(r->var_node.cptr);
		if (p == NLNIL || p->class == BADUSE)
			return (NLNIL);
		switch (p->class) {
		    case VAR:
			    /*
			     * If a variable is
			     * qualified then get
			     * the rvalue by a
			     * lvalue and an ind.
			     */
			    if (r->var_node.qual != TR_NIL)
				    goto ind;
			    q = p->type;
			    if (q == NIL)
				    return (NLNIL);
#			    ifdef OBJ
				w = width(q);
				switch (w) {
				    case 8:
					(void) put(2, O_RV8 | bn << 8+INDX,
						(int)p->value[0]);
					break;
				    case 4:
					(void) put(2, O_RV4 | bn << 8+INDX,
						(int)p->value[0]);
					break;
				    case 2:
					(void) put(2, O_RV2 | bn << 8+INDX,
						(int)p->value[0]);
					break;
				    case 1:
					(void) put(2, O_RV1 | bn << 8+INDX,
						(int)p->value[0]);
					break;
				    default:
					(void) put(3, O_RV | bn << 8+INDX,
						(int)p->value[0], w);
				}
#			   endif OBJ
#			   ifdef PC
				if ( required == RREQ ) {
				    putRV( p -> symbol , bn , p -> value[0] ,
					    p -> extra_flags , p2type( q ) );
				} else {
				    putLV( p -> symbol , bn , p -> value[0] ,
					    p -> extra_flags , p2type( q ) );
				}
#			   endif PC
			   return (q);

		    case WITHPTR:
		    case REF:
			    /*
			     * A lvalue for these
			     * is actually what one
			     * might consider a rvalue.
			     */
ind:
			    q = lvalue(r, NOFLAGS , LREQ );
			    if (q == NIL)
				    return (NLNIL);
#			    ifdef OBJ
				w = width(q);
				switch (w) {
				    case 8:
					    (void) put(1, O_IND8);
					    break;
				    case 4:
					    (void) put(1, O_IND4);
					    break;
				    case 2:
					    (void) put(1, O_IND2);
					    break;
				    case 1:
					    (void) put(1, O_IND1);
					    break;
				    default:
					    (void) put(2, O_IND, w);
				}
#			    endif OBJ
#			    ifdef PC
				if ( required == RREQ ) {
				    putop( PCCOM_UNARY PCC_MUL , p2type( q ) );
				}
#			    endif PC
			    return (q);

		    case CONST:
			    if (r->var_node.qual != TR_NIL) {
				error("%s is a constant and cannot be qualified", r->var_node.cptr);
				return (NLNIL);
			    }
			    q = p->type;
			    if (q == NLNIL)
				    return (NLNIL);
			    if (q == nl+TSTR) {
				    /*
				     * Find the size of the string
				     * constant if needed.
				     */
				    cp = (char *) p->ptr[0];
cstrng:
				    cp1 = cp;
				    for (c = 0; *cp++; c++)
					    continue;
				    w = c;
				    if (contype != NIL && !opt('s')) {
					    if (width(contype) < c && classify(contype) == TSTR) {
						    error("Constant string too long");
						    return (NLNIL);
					    }
					    w = width(contype);
				    }
#				    ifdef OBJ
					(void) put(2, O_CONG, w);
					putstr(cp1, w - c);
#				    endif OBJ
#				    ifdef PC
					putCONG( cp1 , w , required );
#				    endif PC
				    /*
				     * Define the string temporarily
				     * so later people can know its
				     * width.
				     * cleaned out by stat.
				     */
				    q = defnl((char *) 0, STR, NLNIL, w);
				    q->type = q;
				    return (q);
			    }
			    if (q == nl+T1CHAR) {
#				    ifdef OBJ
					(void) put(2, O_CONC, (int)p->value[0]);
#				    endif OBJ
#				    ifdef PC
					putleaf( PCC_ICON , p -> value[0] , 0
						, PCCT_CHAR , (char *) 0 );
#				    endif PC
				    return (q);
			    }
			    /*
			     * Every other kind of constant here
			     */
			    switch (width(q)) {
			    case 8:
#ifndef DEBUG
#				    ifdef OBJ
					(void) put(2, O_CON8, p->real);
#				    endif OBJ
#				    ifdef PC
					putCON8( p -> real );
#				    endif PC
#else
				    if (hp21mx) {
					    f.pdouble = p->real;
					    conv((int *) (&f.pdouble));
					    l = f.plong[1];
					    (void) put(2, O_CON4, l);
				    } else
#					    ifdef OBJ
						(void) put(2, O_CON8, p->real);
#					    endif OBJ
#					    ifdef PC
						putCON8( p -> real );
#					    endif PC
#endif
				    break;
			    case 4:
#				    ifdef OBJ
					(void) put(2, O_CON4, p->range[0]);
#				    endif OBJ
#				    ifdef PC
					putleaf( PCC_ICON , (int) p->range[0] , 0
						, PCCT_INT , (char *) 0 );
#				    endif PC
				    break;
			    case 2:
#				    ifdef OBJ
					(void) put(2, O_CON2, (short)p->range[0]);
#				    endif OBJ
#				    ifdef PC
					putleaf( PCC_ICON , (short) p -> range[0]
						, 0 , PCCT_SHORT , (char *) 0 );
#				    endif PC
				    break;
			    case 1:
#				    ifdef OBJ
					(void) put(2, O_CON1, p->value[0]);
#				    endif OBJ
#				    ifdef PC
					putleaf( PCC_ICON , p -> value[0] , 0
						, PCCT_CHAR , (char *) 0 );
#				    endif PC
				    break;
			    default:
				    panic("rval");
			    }
			    return (q);

		    case FUNC:
		    case FFUNC:
			    /*
			     * Function call with no arguments.
			     */
			    if (r->var_node.qual != TR_NIL) {
				    error("Can't qualify a function result value");
				    return (NLNIL);
			    }
#			    ifdef OBJ
				return (funccod(r));
#			    endif OBJ
#			    ifdef PC
				return (pcfunccod( r ));
#			    endif PC

		    case TYPE:
			    error("Type names (e.g. %s) allowed only in declarations", p->symbol);
			    return (NLNIL);

		    case PROC:
		    case FPROC:
			    error("Procedure %s found where expression required", p->symbol);
			    return (NLNIL);
		    default:
			    panic("rvid");
		}
	/*
	 * Constant sets
	 */
	case T_CSET:
#		ifdef OBJ
		    if ( precset( r , contype , &csetd ) ) {
			if ( csetd.csettype == NIL ) {
			    return (NLNIL);
			}
			postcset( r , &csetd );
		    } else {
			(void) put( 2, O_PUSH, -lwidth(csetd.csettype));
			postcset( r , &csetd );
			setran( ( csetd.csettype ) -> type );
			(void) put( 2, O_CON24, set.uprbp);
			(void) put( 2, O_CON24, set.lwrb);
			(void) put( 2, O_CTTOT,
				(int)(4 + csetd.singcnt + 2 * csetd.paircnt));
		    }
		    return csetd.csettype;
#		endif OBJ
#		ifdef PC
		    if ( precset( r , contype , &csetd ) ) {
			if ( csetd.csettype == NIL ) {
			    return (NLNIL);
			}
			postcset( r , &csetd );
		    } else {
			putleaf( PCC_ICON , 0 , 0
				, PCCM_ADDTYPE( PCCTM_FTN | PCCT_INT , PCCTM_PTR )
				, "_CTTOT" );
			/*
			 *	allocate a temporary and use it
			 */
			tempnlp = tmpalloc(lwidth(csetd.csettype),
				csetd.csettype, NOREG);
			putLV( (char *) 0 , cbn , tempnlp -> value[ NL_OFFS ] ,
				tempnlp -> extra_flags , PCCTM_PTR|PCCT_STRTY );
			setran( ( csetd.csettype ) -> type );
			putleaf( PCC_ICON , set.lwrb , 0 , PCCT_INT , (char *) 0 );
			putop( PCC_CM , PCCT_INT );
			putleaf( PCC_ICON , set.uprbp , 0 , PCCT_INT , (char *) 0 );
			putop( PCC_CM , PCCT_INT );
			postcset( r , &csetd );
			putop( PCC_CALL , PCCT_INT );
		    }
		    return csetd.csettype;