clas.c

/* -*- mode: c; tabs: 8; hard-tabs: yes; -*- */
/*-
 * 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.
 */

#if !defined(lint) && defined(sccs)
static char sccsid[] = "@(#)clas.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#include "whoami.h"
#include "0.h"
#include "tree.h"
#include "tree_ty.h"

/*
 * This is the array of class names for the classes returned
 * by classify.  The order of the classes is the same as the base
 * of the namelist, with special negative index entries for structures,
 * scalars, pointers, sets and strings to be collapsed into.
 */
const char *clnxxxx[] =
{
	"file", 		/* -7	TFILE */
	"record",		/* -6	TREC */
	"array",		/* -5	TARY */
	"scalar",		/* -4	TSCAL */
	"pointer",		/* -3	TPTR */
	"set",			/* -2	TSET */
	"string",		/* -1	TSTR */
	"SNARK",		/*  0	NIL */
	"Boolean",		/*  1	TBOOL */
	"char", 		/*  2	TCHAR */
	"integer",		/*  3	TINT */
	"real", 		/*  4	TREAL */
	"\"nil\"",		/*  5	TNIL */
};

const char **clnames = &clnxxxx[-(TFIRST)];

/*
 * Classify takes a pointer to a type and returns one of several
 * interesting group classifications for easy use.
 */
int
classify(p1)
	struct nl *p1;
{
	register struct nl *p;

	p = p1;
swit:
	if (p == NLNIL) {
		nocascade();
		return (TNONE);
	}
	if (p == &nl[TSTR])
		return (TSTR);
	if ( p == &nl[ TSET ] ) {
	    return TSET;
	}
	switch (p->class) {
		case PTR:
			return (TPTR);
		case ARRAY:
			if (p->type == nl+T1CHAR)
				return (TSTR);
			return (TARY);
		case STR:
			return (TSTR);
		case SET:
			return (TSET);
		case CRANGE:
		case RANGE:
			p = p->type;
			goto swit;
		case TYPE:
			if (p <= nl+TLAST)
				return (p - nl);
			panic("clas2");
		case FILET:
			return (TFILE);
		case RECORD:
			return (TREC);
		case SCAL:
			return (TSCAL);
		default:
			{
			    panic("clas");
			    return(TNONE);
			}
	}
}


#ifndef PI0
/*
 * Is p a text file?
 */
int
text(p)
        struct nl *p;
{
	return (p != NIL && p->class == FILET && p->type == nl+T1CHAR);
}
#endif


/*
 * Scalar returns a pointer to
 * the the base scalar type of
 * its argument if its argument
 * is a SCALar else NIL.
 */
struct nl *
scalar(p1)
        struct nl *p1;
{
	register struct nl *p;

	p = p1;
	if (p == NLNIL)
		return (NLNIL);
	if (p->class == RANGE || p->class == CRANGE)
		p = p->type;
	if (p == NLNIL)
		return (NLNIL);
	return (p->class == SCAL ? p : NLNIL);
}

/*
 * Isa tells whether p is one of a group of namelist classes.  The
 * classes wanted are specified by the characters in s.
 * (Note that s would more efficiently, if less clearly, be given
 * by a mask.)
 */
int
isa(p, s)
	register struct nl *p;
	char *s;
{
	register int i;
	register char *cp;

	if (p == NIL)
		return (TNONE);
	/*
	 * map ranges down to
	 * the base type
	 */
	if (p->class == RANGE) {
		p = p->type;
	}
	/*
	 * the following character/class
	 * associations are made:
	 *
	 *	s	scalar
	 *	b	Boolean
	 *	c	character
	 *	i	integer
	 *	d	double (real)
	 *	t	set
	 */
	switch (p->class) {
		case SET:
			i = TDOUBLE+1;
			break;
		case SCAL:
			i = 0;
			break;
		case CRANGE:
			/*
			 * find the base type of a conformant array range
			 */
			switch (classify(p->type)) {
				case TBOOL: i = 1; break;
				case TCHAR: i = 2; break;
				case TINT: i = 3; break;
				case TSCAL: i = 0; break;
				default:
					panic( "isa" );
			}
			break;
		default:
			i = p - nl;
	}
	if (i >= 0 && i <= TDOUBLE+1) {
		i = "sbcidt"[i];
		cp = s;
		while (*cp)
			if (*cp++ == i)
				return (1);
	}
	return (TNONE);
}


/*
 * Isnta is !isa
 */
int
isnta(p, s)
	struct nl *p;
	char *s;
{

	return (!isa(p, s));
}

/*
 * "shorthand"
 */
const char *
nameof(p)
struct nl *p;
{

	return (clnames[classify(p)]);
}


#ifndef PI0
/*
 *  find out for sure what kind of node this is being passed
 *  possibly several different kinds of node are passed to it
 */
int nowexp(r)
	struct tnode *r;
{
	if (r->tag == T_WEXP) {
		if (r->var_node.cptr == NIL)
			error("Oct/hex allowed only on writeln/write calls");
		else
			error("Width expressions allowed only in writeln/write calls");
		return (1);
	}
	return (0);
}
#endif

    /*
     *  is a variable a local, a formal parameter, or a global?
     *  all this from just the offset:
     *      globals are at levels 0 or 1
     *      positives are parameters
     *      negative evens are locals
     */
/*ARGSUSED*/
int whereis( offset , other_flags )
	int	offset;
	char	other_flags;
{
#ifdef OBJ
	(void) other_flags;
	return ( offset >= 0 ? PARAMVAR : LOCALVAR );
#endif /*OBJ*/
#ifdef PC
	switch ( other_flags & ( NGLOBAL | NPARAM | NLOCAL | NNLOCAL) ) {
		default:
			panic( "whereis" );
		case NGLOBAL:
			return GLOBALVAR;
		case NPARAM:
			return PARAMVAR;
		case NNLOCAL:
			return NAMEDLOCALVAR;
		case NLOCAL:
			return LOCALVAR;
	}
#endif /*PC*/
}