eval.c

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/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ozan Yigit at York University.
 *
 * 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[] = "@(#)eval.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

/*
 * eval.c
 * Facility: m4 macro processor
 * by: oz
 */

#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"
#include "pathnames.h"

/*
 * eval - evaluate built-in macros.
 *	  argc - number of elements in argv.
 *	  argv - element vector :
 *			argv[0] = definition of a user
 *				  macro or nil if built-in.
 *			argv[1] = name of the macro or
 *				  built-in.
 *			argv[2] = parameters to user-defined
 *			   .	  macro or built-in.
 *			   .
 *
 * Note that the minimum value for argc is 3. A call in the form
 * of macro-or-builtin() will result in:
 *			argv[0] = nullstr
 *			argv[1] = macro-or-builtin
 *			argv[2] = nullstr
 */

void
eval(argv, argc, td)
register char *argv[];
register int argc;
register int td;
{
	register int c, n;
	static int sysval = 0;

#ifdef DEBUG
	printf("argc = %d\n", argc);
	for (n = 0; n < argc; n++)
		printf("argv[%d] = %s\n", n, argv[n]);
#endif
 /*
  * if argc == 3 and argv[2] is null, then we
  * have macro-or-builtin() type call. We adjust
  * argc to avoid further checking..
  */
	if (argc == 3 && !*(argv[2]))
		argc--;

	switch (td & ~STATIC) {

	case DEFITYPE:
		if (argc > 2)
			dodefine(argv[2], (argc > 3) ? argv[3] : null);
		break;

	case PUSDTYPE:
		if (argc > 2)
			dopushdef(argv[2], (argc > 3) ? argv[3] : null);
		break;

	case DUMPTYPE:
		dodump(argv, argc);
		break;

	case EXPRTYPE:
	/*
	 * doexpr - evaluate arithmetic
	 * expression
	 */
		if (argc > 2)
			pbnum(expr(argv[2]));
		break;

	case IFELTYPE:
		if (argc > 4)
			doifelse(argv, argc);
		break;

	case IFDFTYPE:
	/*
	 * doifdef - select one of two
	 * alternatives based on the existence of
	 * another definition
	 */
		if (argc > 3) {
			if (lookup(argv[2]) != nil)
				pbstr(argv[3]);
			else if (argc > 4)
				pbstr(argv[4]);
		}
		break;

	case LENGTYPE:
	/*
	 * dolen - find the length of the
	 * argument
	 */
		if (argc > 2)
			pbnum((argc > 2) ? strlen(argv[2]) : 0);
		break;

	case INCRTYPE:
	/*
	 * doincr - increment the value of the
	 * argument
	 */
		if (argc > 2)
			pbnum(atoi(argv[2]) + 1);
		break;

	case DECRTYPE:
	/*
	 * dodecr - decrement the value of the
	 * argument
	 */
		if (argc > 2)
			pbnum(atoi(argv[2]) - 1);
		break;

	case SYSCTYPE:
	/*
	 * dosys - execute system command
	 */
		if (argc > 2)
			sysval = system(argv[2]);
		break;

	case SYSVTYPE:
	/*
	 * dosysval - return value of the last
	 * system call.
	 * 
	 */
		pbnum(sysval);
		break;

	case INCLTYPE:
		if (argc > 2)
			if (!doincl(argv[2]))
				oops("%s: %s", argv[2], strerror(errno));
		break;

	case SINCTYPE:
		if (argc > 2)
			(void) doincl(argv[2]);
		break;
#ifdef EXTENDED
	case PASTTYPE:
		if (argc > 2)
			if (!dopaste(argv[2]))
				oops("%s: %s", argv[2], strerror(errno));
		break;

	case SPASTYPE:
		if (argc > 2)
			(void) dopaste(argv[2]);
		break;
#endif
	case CHNQTYPE:
		dochq(argv, argc);
		break;

	case CHNCTYPE:
		dochc(argv, argc);
		break;

	case SUBSTYPE:
	/*
	 * dosub - select substring
	 * 
	 */
		if (argc > 3)
			dosub(argv, argc);
		break;

	case SHIFTYPE:
	/*
	 * doshift - push back all arguments
	 * except the first one (i.e. skip
	 * argv[2])
	 */
		if (argc > 3) {
			for (n = argc - 1; n > 3; n--) {
				putback(rquote);
				pbstr(argv[n]);
				putback(lquote);
				putback(',');
			}
			putback(rquote);
			pbstr(argv[3]);
			putback(lquote);
		}
		break;

	case DIVRTYPE:
		if (argc > 2 && (n = atoi(argv[2])) != 0)
			dodiv(n);
		else {
			active = stdout;
			oindex = 0;
		}
		break;

	case UNDVTYPE:
		doundiv(argv, argc);
		break;

	case DIVNTYPE:
	/*
	 * dodivnum - return the number of
	 * current output diversion
	 */
		pbnum(oindex);
		break;

	case UNDFTYPE:
	/*
	 * doundefine - undefine a previously
	 * defined macro(s) or m4 keyword(s).
	 */
		if (argc > 2)
			for (n = 2; n < argc; n++)
				remhash(argv[n], ALL);
		break;

	case POPDTYPE:
	/*
	 * dopopdef - remove the topmost
	 * definitions of macro(s) or m4
	 * keyword(s).
	 */
		if (argc > 2)
			for (n = 2; n < argc; n++)
				remhash(argv[n], TOP);
		break;

	case MKTMTYPE:
	/*
	 * dotemp - create a temporary file
	 */
		if (argc > 2)
			pbstr(mktemp(argv[2]));
		break;

	case TRNLTYPE:
	/*
	 * dotranslit - replace all characters in
	 * the source string that appears in the
	 * "from" string with the corresponding
	 * characters in the "to" string.
	 */
		if (argc > 3) {
			char temp[MAXTOK];
			if (argc > 4)
				map(temp, argv[2], argv[3], argv[4]);
			else
				map(temp, argv[2], argv[3], null);
			pbstr(temp);
		}
		else if (argc > 2)
			pbstr(argv[2]);
		break;

	case INDXTYPE:
	/*
	 * doindex - find the index of the second
	 * argument string in the first argument
	 * string. -1 if not present.
	 */
		pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
		break;

	case ERRPTYPE:
	/*
	 * doerrp - print the arguments to stderr
	 * file
	 */
		if (argc > 2) {
			for (n = 2; n < argc; n++)
				fprintf(stderr, "%s ", argv[n]);
			fprintf(stderr, "\n");
		}
		break;

	case DNLNTYPE:
	/*
	 * dodnl - eat-up-to and including
	 * newline
	 */
		while ((c = gpbc()) != '\n' && c != EOF)
			;
		break;

	case M4WRTYPE:
	/*
	 * dom4wrap - set up for
	 * wrap-up/wind-down activity
	 */
		m4wraps = (argc > 2) ? xstrdup(argv[2]) : null;
		break;

	case EXITTYPE:
	/*
	 * doexit - immediate exit from m4.
	 */
		exit((argc > 2) ? atoi(argv[2]) : 0);
		break;

	case DEFNTYPE:
		if (argc > 2)
			for (n = 2; n < argc; n++)
				dodefn(argv[n]);
		break;

	default:
		oops("%s: major botch.", "eval");
		break;
	}
}

char *dumpfmt = "`%s'\t`%s'\n";	       /* format string for dumpdef   */

/*
 * expand - user-defined macro expansion
 */
void
expand(argv, argc)
register char *argv[];
register int argc;
{
	register char *t;
	register char *p;
	register int n;
	register int argno;

	t = argv[0];		       /* defn string as a whole */
	p = t;
	while (*p)
		p++;
	p--;			       /* last character of defn */
	while (p > t) {
		if (*(p - 1) != ARGFLAG)
			putback(*p);
		else {
			switch (*p) {