xref: /plan9/sys/src/cmd/pic/input.c (revision 14f51593fd82e19ba95969a8c07ff71131015979)
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <ctype.h>
5 #include <errno.h>
6 #include "pic.h"
7 #include "y.tab.h"
8 
9 Infile	infile[10];
10 Infile	*curfile = infile;
11 
12 #define	MAXSRC	50
13 Src	src[MAXSRC];	/* input source stack */
14 Src	*srcp	= src;
15 
16 void	do_thru(void);
17 int	nextchar(void);
18 int	getarg(char *);
19 void	freedef(char *);
20 int	baldelim(int, char *);
21 
pushsrc(int type,char * ptr)22 void pushsrc(int type, char *ptr)	/* new input source */
23 {
24 	if (++srcp >= src + MAXSRC)
25 		ERROR "inputs nested too deep" FATAL;
26 	srcp->type = type;
27 	srcp->sp = ptr;
28 	if (dbg > 1) {
29 		printf("\n%3d ", srcp - src);
30 		switch (srcp->type) {
31 		case File:
32 			printf("push file %s\n", ((Infile *)ptr)->fname);
33 			break;
34 		case Macro:
35 			printf("push macro <%s>\n", ptr);
36 			break;
37 		case Char:
38 			printf("push char <%c>\n", *ptr);
39 			break;
40 		case Thru:
41 			printf("push thru\n");
42 			break;
43 		case String:
44 			printf("push string <%s>\n", ptr);
45 			break;
46 		case Free:
47 			printf("push free <%s>\n", ptr);
48 			break;
49 		default:
50 			ERROR "pushed bad type %d", srcp->type FATAL;
51 		}
52 	}
53 }
54 
popsrc(void)55 void popsrc(void)	/* restore an old one */
56 {
57 	if (srcp <= src)
58 		ERROR "too many inputs popped" FATAL;
59 	if (dbg > 1) {
60 		printf("%3d ", srcp - src);
61 		switch (srcp->type) {
62 		case File:
63 			printf("pop file\n");
64 			break;
65 		case Macro:
66 			printf("pop macro\n");
67 			break;
68 		case Char:
69 			printf("pop char <%c>\n", *srcp->sp);
70 			break;
71 		case Thru:
72 			printf("pop thru\n");
73 			break;
74 		case String:
75 			printf("pop string\n");
76 			break;
77 		case Free:
78 			printf("pop free\n");
79 			break;
80 		default:
81 			ERROR "pop weird input %d", srcp->type FATAL;
82 		}
83 	}
84 	srcp--;
85 }
86 
definition(char * s)87 void definition(char *s)	/* collect definition for s and install */
88 				/* definitions picked up lexically */
89 {
90 	char *p;
91 	struct symtab *stp;
92 
93 	p = delimstr("definition");
94 	stp = lookup(s);
95 	if (stp != NULL) {	/* it's there before */
96 		if (stp->s_type != DEFNAME) {
97 			ERROR "%s used as variable and definition", s WARNING;
98 			return;
99 		}
100 		free(stp->s_val.p);
101 		stp->s_val.p = p;
102 	} else {
103 		YYSTYPE u;
104 		u.p = p;
105 		makevar(tostring(s), DEFNAME, u);
106 	}
107 	dprintf("installing %s as `%s'\n", s, p);
108 }
109 
delimstr(char * s)110 char *delimstr(char *s)	/* get body of X ... X */
111 				/* message if too big */
112 {
113 	int c, delim, rdelim, n, deep;
114 	static char *buf = NULL;
115 	static int nbuf = 0;
116 	char *p;
117 
118 	if (buf == NULL)
119 		buf = grow(buf, "buf", nbuf += 1000, sizeof(buf[0]));
120 	while ((delim = input()) == ' ' || delim == '\t' || delim == '\n')
121 		;
122 	rdelim = baldelim(delim, "{}");		/* could be "(){}[]`'" */
123 	deep = 1;
124 	for (p = buf; ; ) {
125 		c = input();
126 		if (c == rdelim)
127 			if (--deep == 0)
128 				break;
129 		if (c == delim)
130 			deep++;
131 		if (p >= buf + nbuf) {
132 			n = p - buf;
133 			buf = grow(buf, "buf", nbuf += 1000, sizeof(buf[0]));
134 			p = buf + n;
135 		}
136 		if (c == EOF)
137 			ERROR "end of file in %s %c %.20s... %c", s, delim, buf, delim FATAL;
138 		*p++ = c;
139 	}
140 	*p = '\0';
141 	dprintf("delimstr %s %c <%s> %c\n", s, delim, buf, delim);
142 	return tostring(buf);
143 }
144 
baldelim(int c,char * s)145 baldelim(int c, char *s)	/* replace c by balancing entry in s */
146 {
147 	for ( ; *s; s += 2)
148 		if (*s == c)
149 			return s[1];
150 	return c;
151 }
152 
undefine(char * s)153 void undefine(char *s)	/* undefine macro */
154 {
155 	while (*s != ' ' && *s != '\t')		/* skip "undef..." */
156 		s++;
157 	while (*s == ' ' || *s == '\t')
158 		s++;
159 	freedef(s);
160 }
161 
162 
163 Arg	args[10];	/* argument frames */
164 Arg	*argfp = args;	/* frame pointer */
165 int	argcnt;		/* number of arguments seen so far */
166 
dodef(struct symtab * stp)167 void dodef(struct symtab *stp)	/* collect args and switch input to defn */
168 {
169 	int i, len;
170 	char *p;
171 	Arg *ap;
172 
173 	ap = argfp+1;
174 	if (ap >= args+10)
175 		ERROR "arguments too deep" FATAL;
176 	argcnt = 0;
177 	if (input() != '(')
178 		ERROR "disaster in dodef" FATAL;
179 	if (ap->argval == 0)
180 		ap->argval = malloc(1000);
181 	for (p = ap->argval; (len = getarg(p)) != -1; p += len) {
182 		ap->argstk[argcnt++] = p;
183 		if (input() == ')')
184 			break;
185 	}
186 	for (i = argcnt; i < MAXARGS; i++)
187 		ap->argstk[i] = "";
188 	if (dbg)
189 		for (i = 0; i < argcnt; i++)
190 			printf("arg %d.%d = <%s>\n", ap-args, i+1, ap->argstk[i]);
191 	argfp = ap;
192 	pushsrc(Macro, stp->s_val.p);
193 }
194 
getarg(char * p)195 getarg(char *p)	/* pick up single argument, store in p, return length */
196 {
197 	int n, c, npar;
198 
199 	n = npar = 0;
200 	for ( ;; ) {
201 		c = input();
202 		if (c == EOF)
203 			ERROR "end of file in getarg" FATAL;
204 		if (npar == 0 && (c == ',' || c == ')'))
205 			break;
206 		if (c == '"')	/* copy quoted stuff intact */
207 			do {
208 				*p++ = c;
209 				n++;
210 			} while ((c = input()) != '"' && c != EOF);
211 		else if (c == '(')
212 			npar++;
213 		else if (c == ')')
214 			npar--;
215 		n++;
216 		*p++ = c;
217 	}
218 	*p = 0;
219 	unput(c);
220 	return(n + 1);
221 }
222 
223 #define	PBSIZE	2000
224 char	pbuf[PBSIZE];		/* pushback buffer */
225 char	*pb	= pbuf-1;	/* next pushed back character */
226 
227 char	ebuf[200];		/* collect input here for error reporting */
228 char	*ep	= ebuf;
229 
230 int	begin	= 0;
231 extern	int	thru;
232 extern	struct symtab	*thrudef;
233 extern	char	*untilstr;
234 
input(void)235 input(void)
236 {
237 	register int c;
238 
239 	if (thru && begin) {
240 		do_thru();
241 		begin = 0;
242 	}
243 	c = nextchar();
244 	if (dbg > 1)
245 		printf(" <%c>", c);
246 	if (ep >= ebuf + sizeof ebuf)
247 		ep = ebuf;
248 	return *(unsigned char *)ep++ = c;
249 }
250 
nextchar(void)251 nextchar(void)
252 {
253 	register int c;
254 
255 	c = 0;
256   loop:
257 	switch (srcp->type) {
258 	case Free:	/* free string */
259 		free(srcp->sp);
260 		popsrc();
261 		goto loop;
262 	case Thru:	/* end of pushed back line */
263 		begin = 1;
264 		popsrc();
265 		c = '\n';
266 		break;
267 	case Char:
268 		if (pb >= pbuf) {
269 			c = *pb--;
270 			popsrc();
271 			break;
272 		} else {	/* can't happen? */
273 			popsrc();
274 			goto loop;
275 		}
276 	case String:
277 		c = *srcp->sp++;
278 		if (c == '\0') {
279 			popsrc();
280 			goto loop;
281 		} else {
282 			if (*srcp->sp == '\0')	/* empty, so pop */
283 				popsrc();
284 			break;
285 		}
286 	case Macro:
287 		c = *srcp->sp++;
288 		if (c == '\0') {
289 			if (--argfp < args)
290 				ERROR "argfp underflow" FATAL;
291 			popsrc();
292 			goto loop;
293 		} else if (c == '$' && isdigit(*srcp->sp)) {
294 			int n = 0;
295 			while (isdigit(*srcp->sp))
296 				n = 10 * n + *srcp->sp++ - '0';
297 			if (n > 0 && n <= MAXARGS)
298 				pushsrc(String, argfp->argstk[n-1]);
299 			goto loop;
300 		}
301 		break;
302 	case File:
303 		c = getc(curfile->fin);
304 		if (c == EOF) {
305 			if (curfile == infile)
306 				ERROR "end of file inside .PS/.PE" FATAL;
307 			if (curfile->fin != stdin) {
308 				fclose(curfile->fin);
309 				free(curfile->fname);	/* assumes allocated */
310 			}
311 			curfile--;
312 			printlf(curfile->lineno, curfile->fname);
313 			popsrc();
314 			thru = 0;	/* chicken out */
315 			thrudef = 0;
316 			if (untilstr) {
317 				free(untilstr);
318 				untilstr = 0;
319 			}
320 			goto loop;
321 		}
322 		if (c == '\n')
323 			curfile->lineno++;
324 		break;
325 	}
326 	return c;
327 }
328 
do_thru(void)329 void do_thru(void)	/* read one line, make into a macro expansion */
330 {
331 	int c, i;
332 	char *p;
333 	Arg *ap;
334 
335 	ap = argfp+1;
336 	if (ap >= args+10)
337 		ERROR "arguments too deep" FATAL;
338 	if (ap->argval == NULL)
339 		ap->argval = malloc(1000);
340 	p = ap->argval;
341 	argcnt = 0;
342 	c = nextchar();
343 	if (thru == 0) {	/* end of file was seen, so thru is done */
344 		unput(c);
345 		return;
346 	}
347 	for ( ; c != '\n' && c != EOF; ) {
348 		if (c == ' ' || c == '\t') {
349 			c = nextchar();
350 			continue;
351 		}
352 		ap->argstk[argcnt++] = p;
353 		if (c == '"') {
354 			do {
355 				*p++ = c;
356 				if ((c = nextchar()) == '\\') {
357 					*p++ = c;
358 					*p++ = nextchar();
359 					c = nextchar();
360 				}
361 			} while (c != '"' && c != '\n' && c != EOF);
362 			*p++ = '"';
363 			if (c == '"')
364 				c = nextchar();
365 		} else {
366 			do {
367 				*p++ = c;
368 			} while ((c = nextchar())!=' ' && c!='\t' && c!='\n' && c!=',' && c!=EOF);
369 			if (c == ',')
370 				c = nextchar();
371 		}
372 		*p++ = '\0';
373 	}
374 	if (c == EOF)
375 		ERROR "unexpected end of file in do_thru" FATAL;
376 	if (argcnt == 0) {	/* ignore blank line */
377 		pushsrc(Thru, (char *) 0);
378 		return;
379 	}
380 	for (i = argcnt; i < MAXARGS; i++)
381 		ap->argstk[i] = "";
382 	if (dbg)
383 		for (i = 0; i < argcnt; i++)
384 			printf("arg %d.%d = <%s>\n", ap-args, i+1, ap->argstk[i]);
385 	if (strcmp(ap->argstk[0], ".PE") == 0) {
386 		thru = 0;
387 		thrudef = 0;
388 		pushsrc(String, "\n.PE\n");
389 		return;
390 	}
391 	if (untilstr && strcmp(ap->argstk[0], untilstr) == 0) {
392 		thru = 0;
393 		thrudef = 0;
394 		free(untilstr);
395 		untilstr = 0;
396 		return;
397 	}
398 	pushsrc(Thru, (char *) 0);
399 	dprintf("do_thru pushing back <%s>\n", thrudef->s_val.p);
400 	argfp = ap;
401 	pushsrc(Macro, thrudef->s_val.p);
402 }
403 
unput(int c)404 unput(int c)
405 {
406 	if (++pb >= pbuf + sizeof pbuf)
407 		ERROR "pushback overflow" FATAL;
408 	if (--ep < ebuf)
409 		ep = ebuf + sizeof(ebuf) - 1;
410 	*pb = c;
411 	pushsrc(Char, pb);
412 	return c;
413 }
414 
pbstr(char * s)415 void pbstr(char *s)
416 {
417 	pushsrc(String, s);
418 }
419 
errcheck(double x,char * s)420 double errcheck(double x, char  *s)
421 {
422 	extern int errno;
423 
424 	if (errno == EDOM) {
425 		errno = 0;
426 		ERROR "%s argument out of domain", s WARNING;
427 	} else if (errno == ERANGE) {
428 		errno = 0;
429 		ERROR "%s result out of range", s WARNING;
430 	}
431 	return x;
432 }
433 
434 char	errbuf[200];
435 
436 void	eprint(void);
437 
yyerror(char * s)438 void yyerror(char *s)
439 {
440 	extern char *cmdname;
441 	int ern = errno;	/* cause some libraries clobber it */
442 
443 	if (synerr)
444 		return;
445 	fflush(stdout);
446 	fprintf(stderr, "%s: %s", cmdname, s);
447 	if (ern > 0) {
448 		errno = ern;
449 		perror("???");
450 	}
451 	fprintf(stderr, " near %s:%d\n",
452 		curfile->fname, curfile->lineno+1);
453 	eprint();
454 	synerr = 1;
455 	errno = 0;
456 }
457 
eprint(void)458 void eprint(void)	/* try to print context around error */
459 {
460 	char *p, *q;
461 
462 	p = ep - 1;
463 	if (p > ebuf && *p == '\n')
464 		p--;
465 	for ( ; p >= ebuf && *p != '\n'; p--)
466 		;
467 	while (*p == '\n')
468 		p++;
469 	fprintf(stderr, " context is\n\t");
470 	for (q=ep-1; q>=p && *q!=' ' && *q!='\t' && *q!='\n'; q--)
471 		;
472 	while (p < q)
473 		putc(*p++, stderr);
474 	fprintf(stderr, " >>> ");
475 	while (p < ep)
476 		putc(*p++, stderr);
477 	fprintf(stderr, " <<< ");
478 	while (pb >= pbuf)
479 		putc(*pb--, stderr);
480 	fgets(ebuf, sizeof ebuf, curfile->fin);
481 	fprintf(stderr, "%s", ebuf);
482 	pbstr("\n.PE\n");	/* safety first */
483 	ep = ebuf;
484 }
485 
486 int
yywrap(void)487 yywrap(void)
488 {
489 	return 1;		/* read eof; did not switch inputs */
490 }
491 
492 char	*newfile = 0;		/* filename for file copy */
493 char	*untilstr = 0;		/* string that terminates a thru */
494 int	thru	= 0;		/* 1 if copying thru macro */
495 struct symtab	*thrudef = 0;		/* macro being used */
496 
copyfile(char * s)497 void copyfile(char *s)	/* remember file to start reading from */
498 {
499 	newfile = s;
500 }
501 
copydef(struct symtab * p)502 void copydef(struct symtab *p)	/* remember macro symtab ptr */
503 {
504 	thrudef = p;
505 }
506 
copythru(char * s)507 struct symtab *copythru(char *s)	/* collect the macro name or body for thru */
508 {
509 	struct symtab *p;
510 	char *q, *addnewline(char *);
511 
512 	p = lookup(s);
513 	if (p != NULL) {
514 		if (p->s_type == DEFNAME) {
515 			p->s_val.p = addnewline(p->s_val.p);
516 			return p;
517 		} else
518 			ERROR "%s used as define and name", s FATAL;
519 	}
520 	/* have to collect the definition */
521 	pbstr(s);	/* first char is the delimiter */
522 	q = delimstr("thru body");
523 	s = "nameless";
524 	p = lookup(s);
525 	if (p != NULL) {
526 		if (p->s_val.p)
527 			free(p->s_val.p);
528 		p->s_val.p = q;
529 	} else {
530 		YYSTYPE u;
531 		u.p = q;
532 		p = makevar(tostring(s), DEFNAME, u);
533 	}
534 	p->s_val.p = addnewline(p->s_val.p);
535 	dprintf("installing %s as `%s'\n", s, p->s_val.p);
536 	return p;
537 }
538 
addnewline(char * p)539 char *addnewline(char *p)	/* add newline to end of p */
540 {
541 	int n;
542 
543 	n = strlen(p);
544 	if (p[n-1] != '\n') {
545 		p = realloc(p, n+2);
546 		p[n] = '\n';
547 		p[n+1] = '\0';
548 	}
549 	return p;
550 }
551 
copyuntil(char * s)552 void copyuntil(char *s)	/* string that terminates a thru */
553 {
554 	untilstr = s;
555 }
556 
copy(void)557 void copy(void)	/* begin input from file, etc. */
558 {
559 	FILE *fin;
560 
561 	if (newfile) {
562 		if ((fin = fopen(newfile, "r")) == NULL)
563 			ERROR "can't open file %s", newfile FATAL;
564 		curfile++;
565 		curfile->fin = fin;
566 		curfile->fname = newfile;
567 		curfile->lineno = 0;
568 		printlf(1, curfile->fname);
569 		pushsrc(File, curfile->fname);
570 		newfile = 0;
571 	}
572 	if (thrudef) {
573 		thru = 1;
574 		begin = 1;	/* wrong place */
575 	}
576 }
577 
578 char	shellbuf[1000], *shellp;
579 
shell_init(void)580 void shell_init(void)	/* set up to interpret a shell command */
581 {
582 	sprintf(shellbuf, "rc -c '");
583 	shellp = shellbuf + strlen(shellbuf);
584 }
585 
shell_text(char * s)586 void shell_text(char *s)	/* add string to command being collected */
587 {
588 	while (*shellp++ = *s++)
589 		;
590 	shellp--;
591 }
592 
shell_exec(void)593 void shell_exec(void)	/* do it */
594 {
595 	*shellp++ = '\'';
596 	*shellp = '\0';
597 	system(shellbuf);
598 }
599