xref: /freebsd/usr.bin/m4/eval.c (revision b7a1a0a5ff8895e6a5c9404d02357ac9e2eb8091)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Ozan Yigit at York University.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static char sccsid[] = "@(#)eval.c	8.1 (Berkeley) 6/6/93";
39 #endif /* not lint */
40 
41 /*
42  * eval.c
43  * Facility: m4 macro processor
44  * by: oz
45  */
46 
47 #include <sys/types.h>
48 #include <errno.h>
49 #include <unistd.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include "mdef.h"
54 #include "stdd.h"
55 #include "extern.h"
56 #include "pathnames.h"
57 
58 /*
59  * eval - evaluate built-in macros.
60  *	  argc - number of elements in argv.
61  *	  argv - element vector :
62  *			argv[0] = definition of a user
63  *				  macro or nil if built-in.
64  *			argv[1] = name of the macro or
65  *				  built-in.
66  *			argv[2] = parameters to user-defined
67  *			   .	  macro or built-in.
68  *			   .
69  *
70  * Note that the minimum value for argc is 3. A call in the form
71  * of macro-or-builtin() will result in:
72  *			argv[0] = nullstr
73  *			argv[1] = macro-or-builtin
74  *			argv[2] = nullstr
75  */
76 
77 void
78 eval(argv, argc, td)
79 register char *argv[];
80 register int argc;
81 register int td;
82 {
83 	register int c, n;
84 	static int sysval = 0;
85 
86 #ifdef DEBUG
87 	printf("argc = %d\n", argc);
88 	for (n = 0; n < argc; n++)
89 		printf("argv[%d] = %s\n", n, argv[n]);
90 #endif
91  /*
92   * if argc == 3 and argv[2] is null, then we
93   * have macro-or-builtin() type call. We adjust
94   * argc to avoid further checking..
95   */
96 	if (argc == 3 && !*(argv[2]))
97 		argc--;
98 
99 	switch (td & ~STATIC) {
100 
101 	case DEFITYPE:
102 		if (argc > 2)
103 			dodefine(argv[2], (argc > 3) ? argv[3] : null);
104 		break;
105 
106 	case PUSDTYPE:
107 		if (argc > 2)
108 			dopushdef(argv[2], (argc > 3) ? argv[3] : null);
109 		break;
110 
111 	case DUMPTYPE:
112 		dodump(argv, argc);
113 		break;
114 
115 	case EXPRTYPE:
116 	/*
117 	 * doexpr - evaluate arithmetic
118 	 * expression
119 	 */
120 		if (argc > 2)
121 			pbnum(expr(argv[2]));
122 		break;
123 
124 	case IFELTYPE:
125 		if (argc > 4)
126 			doifelse(argv, argc);
127 		break;
128 
129 	case IFDFTYPE:
130 	/*
131 	 * doifdef - select one of two
132 	 * alternatives based on the existence of
133 	 * another definition
134 	 */
135 		if (argc > 3) {
136 			if (lookup(argv[2]) != nil)
137 				pbstr(argv[3]);
138 			else if (argc > 4)
139 				pbstr(argv[4]);
140 		}
141 		break;
142 
143 	case LENGTYPE:
144 	/*
145 	 * dolen - find the length of the
146 	 * argument
147 	 */
148 		if (argc > 2)
149 			pbnum((argc > 2) ? strlen(argv[2]) : 0);
150 		break;
151 
152 	case INCRTYPE:
153 	/*
154 	 * doincr - increment the value of the
155 	 * argument
156 	 */
157 		if (argc > 2)
158 			pbnum(atoi(argv[2]) + 1);
159 		break;
160 
161 	case DECRTYPE:
162 	/*
163 	 * dodecr - decrement the value of the
164 	 * argument
165 	 */
166 		if (argc > 2)
167 			pbnum(atoi(argv[2]) - 1);
168 		break;
169 
170 	case SYSCTYPE:
171 	/*
172 	 * dosys - execute system command
173 	 */
174 		if (argc > 2)
175 			sysval = system(argv[2]);
176 		break;
177 
178 	case SYSVTYPE:
179 	/*
180 	 * dosysval - return value of the last
181 	 * system call.
182 	 *
183 	 */
184 		pbnum(sysval);
185 		break;
186 
187 	case INCLTYPE:
188 		if (argc > 2)
189 			if (!doincl(argv[2]))
190 				oops("%s: %s", argv[2], strerror(errno));
191 		break;
192 
193 	case SINCTYPE:
194 		if (argc > 2)
195 			(void) doincl(argv[2]);
196 		break;
197 #ifdef EXTENDED
198 	case PASTTYPE:
199 		if (argc > 2)
200 			if (!dopaste(argv[2]))
201 				oops("%s: %s", argv[2], strerror(errno));
202 		break;
203 
204 	case SPASTYPE:
205 		if (argc > 2)
206 			(void) dopaste(argv[2]);
207 		break;
208 #endif
209 	case CHNQTYPE:
210 		dochq(argv, argc);
211 		break;
212 
213 	case CHNCTYPE:
214 		dochc(argv, argc);
215 		break;
216 
217 	case SUBSTYPE:
218 	/*
219 	 * dosub - select substring
220 	 *
221 	 */
222 		if (argc > 3)
223 			dosub(argv, argc);
224 		break;
225 
226 	case SHIFTYPE:
227 	/*
228 	 * doshift - push back all arguments
229 	 * except the first one (i.e. skip
230 	 * argv[2])
231 	 */
232 		if (argc > 3) {
233 			for (n = argc - 1; n > 3; n--) {
234 				putback(rquote);
235 				pbstr(argv[n]);
236 				putback(lquote);
237 				putback(',');
238 			}
239 			putback(rquote);
240 			pbstr(argv[3]);
241 			putback(lquote);
242 		}
243 		break;
244 
245 	case DIVRTYPE:
246 		if (argc > 2 && (n = atoi(argv[2])) != 0)
247 			dodiv(n);
248 		else {
249 			active = stdout;
250 			oindex = 0;
251 		}
252 		break;
253 
254 	case UNDVTYPE:
255 		doundiv(argv, argc);
256 		break;
257 
258 	case DIVNTYPE:
259 	/*
260 	 * dodivnum - return the number of
261 	 * current output diversion
262 	 */
263 		pbnum(oindex);
264 		break;
265 
266 	case UNDFTYPE:
267 	/*
268 	 * doundefine - undefine a previously
269 	 * defined macro(s) or m4 keyword(s).
270 	 */
271 		if (argc > 2)
272 			for (n = 2; n < argc; n++)
273 				remhash(argv[n], ALL);
274 		break;
275 
276 	case POPDTYPE:
277 	/*
278 	 * dopopdef - remove the topmost
279 	 * definitions of macro(s) or m4
280 	 * keyword(s).
281 	 */
282 		if (argc > 2)
283 			for (n = 2; n < argc; n++)
284 				remhash(argv[n], TOP);
285 		break;
286 
287 	case MKTMTYPE:
288 	/*
289 	 * dotemp - create a temporary file
290 	 */
291 		if (argc > 2)
292 			pbstr(mktemp(argv[2]));
293 		break;
294 
295 	case TRNLTYPE:
296 	/*
297 	 * dotranslit - replace all characters in
298 	 * the source string that appears in the
299 	 * "from" string with the corresponding
300 	 * characters in the "to" string.
301 	 */
302 		if (argc > 3) {
303 			char temp[MAXTOK];
304 			if (argc > 4)
305 				map(temp, argv[2], argv[3], argv[4]);
306 			else
307 				map(temp, argv[2], argv[3], null);
308 			pbstr(temp);
309 		}
310 		else if (argc > 2)
311 			pbstr(argv[2]);
312 		break;
313 
314 	case INDXTYPE:
315 	/*
316 	 * doindex - find the index of the second
317 	 * argument string in the first argument
318 	 * string. -1 if not present.
319 	 */
320 		pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
321 		break;
322 
323 	case ERRPTYPE:
324 	/*
325 	 * doerrp - print the arguments to stderr
326 	 * file
327 	 */
328 		if (argc > 2) {
329 			for (n = 2; n < argc; n++)
330 				fprintf(stderr, "%s ", argv[n]);
331 			fprintf(stderr, "\n");
332 		}
333 		break;
334 
335 	case DNLNTYPE:
336 	/*
337 	 * dodnl - eat-up-to and including
338 	 * newline
339 	 */
340 		while ((c = gpbc()) != '\n' && c != EOF)
341 			;
342 		break;
343 
344 	case M4WRTYPE:
345 	/*
346 	 * dom4wrap - set up for
347 	 * wrap-up/wind-down activity
348 	 */
349 		m4wraps = (argc > 2) ? xstrdup(argv[2]) : null;
350 		break;
351 
352 	case EXITTYPE:
353 	/*
354 	 * doexit - immediate exit from m4.
355 	 */
356 		exit((argc > 2) ? atoi(argv[2]) : 0);
357 		break;
358 
359 	case DEFNTYPE:
360 		if (argc > 2)
361 			for (n = 2; n < argc; n++)
362 				dodefn(argv[n]);
363 		break;
364 
365 	default:
366 		oops("%s: major botch.", "eval");
367 		break;
368 	}
369 }
370 
371 char *dumpfmt = "`%s'\t`%s'\n";	       /* format string for dumpdef   */
372 
373 /*
374  * expand - user-defined macro expansion
375  */
376 void
377 expand(argv, argc)
378 register char *argv[];
379 register int argc;
380 {
381 	register unsigned char *t;
382 	register unsigned char *p;
383 	register int n;
384 	register int argno;
385 
386 	t = argv[0];		       /* defn string as a whole */
387 	p = t;
388 	while (*p)
389 		p++;
390 	p--;			       /* last character of defn */
391 	while (p > t) {
392 		if (*(p - 1) != ARGFLAG)
393 			putback(*p);
394 		else {
395 			switch (*p) {
396 
397 			case '#':
398 				pbnum(argc - 2);
399 				break;
400 			case '0':
401 			case '1':
402 			case '2':
403 			case '3':
404 			case '4':
405 			case '5':
406 			case '6':
407 			case '7':
408 			case '8':
409 			case '9':
410 				if ((argno = *p - '0') < argc - 1)
411 					pbstr(argv[argno + 1]);
412 				break;
413 			case '*':
414 				for (n = argc - 1; n > 2; n--) {
415 					pbstr(argv[n]);
416 					putback(',');
417 				}
418 				pbstr(argv[2]);
419 				break;
420 			default:
421 				putback(*p);
422 				putback('$');
423 				break;
424 			}
425 			p--;
426 		}
427 		p--;
428 	}
429 	if (p == t)		       /* do last character */
430 		putback(*p);
431 }
432 
433 /*
434  * dodefine - install definition in the table
435  */
436 void
437 dodefine(name, defn)
438 register char *name;
439 register char *defn;
440 {
441 	register ndptr p;
442 
443 	if (!*name)
444 		oops("null definition.");
445 	if (STREQ(name, defn))
446 		oops("%s: recursive definition.", name);
447 	if ((p = lookup(name)) == nil)
448 		p = addent(name);
449 	else if (p->defn != null)
450 		free((char *) p->defn);
451 	if (!*defn)
452 		p->defn = null;
453 	else
454 		p->defn = xstrdup(defn);
455 	p->type = MACRTYPE;
456 }
457 
458 /*
459  * dodefn - push back a quoted definition of
460  *      the given name.
461  */
462 void
463 dodefn(name)
464 char *name;
465 {
466 	register ndptr p;
467 
468 	if ((p = lookup(name)) != nil && p->defn != null) {
469 		putback(rquote);
470 		pbstr(p->defn);
471 		putback(lquote);
472 	}
473 }
474 
475 /*
476  * dopushdef - install a definition in the hash table
477  *      without removing a previous definition. Since
478  *      each new entry is entered in *front* of the
479  *      hash bucket, it hides a previous definition from
480  *      lookup.
481  */
482 void
483 dopushdef(name, defn)
484 register char *name;
485 register char *defn;
486 {
487 	register ndptr p;
488 
489 	if (!*name)
490 		oops("null definition");
491 	if (STREQ(name, defn))
492 		oops("%s: recursive definition.", name);
493 	p = addent(name);
494 	if (!*defn)
495 		p->defn = null;
496 	else
497 		p->defn = xstrdup(defn);
498 	p->type = MACRTYPE;
499 }
500 
501 /*
502  * dodumpdef - dump the specified definitions in the hash
503  *      table to stderr. If nothing is specified, the entire
504  *      hash table is dumped.
505  */
506 void
507 dodump(argv, argc)
508 register char *argv[];
509 register int argc;
510 {
511 	register int n;
512 	ndptr p;
513 
514 	if (argc > 2) {
515 		for (n = 2; n < argc; n++)
516 			if ((p = lookup(argv[n])) != nil)
517 				fprintf(stderr, dumpfmt, p->name,
518 					p->defn);
519 	}
520 	else {
521 		for (n = 0; n < HASHSIZE; n++)
522 			for (p = hashtab[n]; p != nil; p = p->nxtptr)
523 				fprintf(stderr, dumpfmt, p->name,
524 					p->defn);
525 	}
526 }
527 
528 /*
529  * doifelse - select one of two alternatives - loop.
530  */
531 void
532 doifelse(argv, argc)
533 register char *argv[];
534 register int argc;
535 {
536 	cycle {
537 		if (STREQ(argv[2], argv[3]))
538 			pbstr(argv[4]);
539 		else if (argc == 6)
540 			pbstr(argv[5]);
541 		else if (argc > 6) {
542 			argv += 3;
543 			argc -= 3;
544 			continue;
545 		}
546 		break;
547 	}
548 }
549 
550 /*
551  * doinclude - include a given file.
552  */
553 int
554 doincl(ifile)
555 char *ifile;
556 {
557 	if (ilevel + 1 == MAXINP)
558 		oops("too many include files.");
559 	if ((infile[ilevel + 1] = fopen(ifile, "r")) != NULL) {
560 		ilevel++;
561 		bbase[ilevel] = bufbase = bp;
562 		return (1);
563 	}
564 	else
565 		return (0);
566 }
567 
568 #ifdef EXTENDED
569 /*
570  * dopaste - include a given file without any
571  *           macro processing.
572  */
573 int
574 dopaste(pfile)
575 char *pfile;
576 {
577 	FILE *pf;
578 	register int c;
579 
580 	if ((pf = fopen(pfile, "r")) != NULL) {
581 		while ((c = getc(pf)) != EOF)
582 			putc(c, active);
583 		(void) fclose(pf);
584 		return (1);
585 	}
586 	else
587 		return (0);
588 }
589 #endif
590 
591 /*
592  * dochq - change quote characters
593  */
594 void
595 dochq(argv, argc)
596 register char *argv[];
597 register int argc;
598 {
599 	if (argc > 2) {
600 		if (*argv[2])
601 			lquote = *argv[2];
602 		if (argc > 3) {
603 			if (*argv[3])
604 				rquote = *argv[3];
605 		}
606 		else
607 			rquote = lquote;
608 	}
609 	else {
610 		lquote = LQUOTE;
611 		rquote = RQUOTE;
612 	}
613 }
614 
615 /*
616  * dochc - change comment characters
617  */
618 void
619 dochc(argv, argc)
620 register char *argv[];
621 register int argc;
622 {
623 	if (argc > 2) {
624 		if (*argv[2])
625 			scommt = *argv[2];
626 		if (argc > 3) {
627 			if (*argv[3])
628 				ecommt = *argv[3];
629 		}
630 		else
631 			ecommt = ECOMMT;
632 	}
633 	else {
634 		scommt = SCOMMT;
635 		ecommt = ECOMMT;
636 	}
637 }
638 
639 /*
640  * dodivert - divert the output to a temporary file
641  */
642 void
643 dodiv(n)
644 register int n;
645 {
646 	if (n < 0 || n >= MAXOUT)
647 		n = 0;		       /* bitbucket */
648 	if (outfile[n] == NULL) {
649 		m4temp[UNIQUE] = n + '0';
650 		if ((outfile[n] = fopen(m4temp, "w")) == NULL)
651 			oops("%s: cannot divert.", m4temp);
652 	}
653 	oindex = n;
654 	active = outfile[n];
655 }
656 
657 /*
658  * doundivert - undivert a specified output, or all
659  *              other outputs, in numerical order.
660  */
661 void
662 doundiv(argv, argc)
663 register char *argv[];
664 register int argc;
665 {
666 	register int ind;
667 	register int n;
668 
669 	if (argc > 2) {
670 		for (ind = 2; ind < argc; ind++) {
671 			n = atoi(argv[ind]);
672 			if (n > 0 && n < MAXOUT && outfile[n] != NULL)
673 				getdiv(n);
674 
675 		}
676 	}
677 	else
678 		for (n = 1; n < MAXOUT; n++)
679 			if (outfile[n] != NULL)
680 				getdiv(n);
681 }
682 
683 /*
684  * dosub - select substring
685  */
686 void
687 dosub(argv, argc)
688 register char *argv[];
689 register int argc;
690 {
691 	register unsigned char *ap, *fc, *k;
692 	register int nc;
693 
694 	if (argc < 5)
695 		nc = MAXTOK;
696 	else
697 #ifdef EXPR
698 		nc = expr(argv[4]);
699 #else
700 		nc = atoi(argv[4]);
701 #endif
702 	ap = argv[2];		       /* target string */
703 #ifdef EXPR
704 	fc = ap + expr(argv[3]);       /* first char */
705 #else
706 	fc = ap + atoi(argv[3]);       /* first char */
707 #endif
708 	if (fc >= ap && fc < ap + strlen(ap))
709 		for (k = fc + min(nc, strlen(fc)) - 1; k >= fc; k--)
710 			putback(*k);
711 }
712 
713 /*
714  * map:
715  * map every character of s1 that is specified in from
716  * into s3 and replace in s. (source s1 remains untouched)
717  *
718  * This is a standard implementation of map(s,from,to) function of ICON
719  * language. Within mapvec, we replace every character of "from" with
720  * the corresponding character in "to". If "to" is shorter than "from",
721  * than the corresponding entries are null, which means that those
722  * characters dissapear altogether. Furthermore, imagine
723  * map(dest, "sourcestring", "srtin", "rn..*") type call. In this case,
724  * `s' maps to `r', `r' maps to `n' and `n' maps to `*'. Thus, `s'
725  * ultimately maps to `*'. In order to achieve this effect in an efficient
726  * manner (i.e. without multiple passes over the destination string), we
727  * loop over mapvec, starting with the initial source character. if the
728  * character value (dch) in this location is different than the source
729  * character (sch), sch becomes dch, once again to index into mapvec, until
730  * the character value stabilizes (i.e. sch = dch, in other words
731  * mapvec[n] == n). Even if the entry in the mapvec is null for an ordinary
732  * character, it will stabilize, since mapvec[0] == 0 at all times. At the
733  * end, we restore mapvec* back to normal where mapvec[n] == n for
734  * 0 <= n <= 127. This strategy, along with the restoration of mapvec, is
735  * about 5 times faster than any algorithm that makes multiple passes over
736  * destination string.
737  */
738 void
739 map(dest, src, from, to)
740 register char *dest;
741 register char *src;
742 register char *from;
743 register char *to;
744 {
745 	register char *tmp;
746 	register char sch, dch;
747 	static char mapvec[128] = {
748 		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
749 		12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
750 		24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
751 		36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
752 		48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
753 		60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
754 		72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83,
755 		84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
756 		96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107,
757 		108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
758 		120, 121, 122, 123, 124, 125, 126, 127
759 	};
760 
761 	if (*src) {
762 		tmp = from;
763 	/*
764 	 * create a mapping between "from" and
765 	 * "to"
766 	 */
767 		while (*from)
768 			mapvec[*from++] = (*to) ? *to++ : (char) 0;
769 
770 		while (*src) {
771 			sch = *src++;
772 			dch = mapvec[sch];
773 			while (dch != sch) {
774 				sch = dch;
775 				dch = mapvec[sch];
776 			}
777 			if (*dest = dch)
778 				dest++;
779 		}
780 	/*
781 	 * restore all the changed characters
782 	 */
783 		while (*tmp) {
784 			mapvec[*tmp] = *tmp;
785 			tmp++;
786 		}
787 	}
788 	*dest = (char) 0;
789 }
790