xref: /titanic_50/usr/src/cmd/vgrind/vfontedpr.c (revision ae115bc77f6fcde83175c75b4206dc2e50747966)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  */
6 
7 #pragma ident	"%Z%%M%	%I%	%E% SMI"
8 
9 #include <ctype.h>
10 #include <stdio.h>
11 #include <sys/types.h>
12 #include <sys/stat.h>
13 #include <locale.h>
14 #include <euc.h>
15 #include <stdlib.h>
16 
17 #define boolean int
18 #define TRUE 1
19 #define FALSE 0
20 #define NIL 0
21 #define STANDARD 0
22 #define ALTERNATE 1
23 
24 /*
25  * Vfontedpr.
26  *
27  * Dave Presotto 1/12/81 (adapted from an earlier version by Bill Joy)
28  *
29  */
30 
31 #define STRLEN 10		/* length of strings introducing things */
32 #define PNAMELEN 40		/* length of a function/procedure name */
33 #define PSMAX 20		/* size of procedure name stacking */
34 
35 /* regular expression routines */
36 
37 char	*expmatch();		/* match a string to an expression */
38 char	*STRNCMP();		/* a different kind of strncmp */
39 char	*convexp();		/* convert expression to internal form */
40 
41 char	*tgetstr();		/* extract a string-valued capability */
42 boolean	isproc();
43 char	*ctime();
44 char	*strchr();
45 
46 /*
47  *	The state variables
48  */
49 
50 boolean	incomm;			/* in a comment of the primary type */
51 boolean	instr;			/* in a string constant */
52 boolean	inchr;			/* in a string constant */
53 boolean	nokeyw = FALSE;		/* no keywords being flagged */
54 boolean	doindex = FALSE;	/* form an index */
55 boolean twocol = FALSE;		/* in two-column mode */
56 boolean	filter = FALSE;		/* act as a filter (like eqn) */
57 boolean	pass = FALSE;		/* when acting as a filter, pass indicates
58 				 * whether we are currently processing
59 				 * input.
60 				 */
61 boolean	prccont;		/* continue last procedure */
62 int	comtype;		/* type of comment */
63 int	margin;
64 int	psptr;			/* the stack index of the current procedure */
65 char	pstack[PSMAX][PNAMELEN+1];	/* the procedure name stack */
66 int	plstack[PSMAX];		/* the procedure nesting level stack */
67 int	blklevel;		/* current nesting level */
68 int	prclevel;		/* nesting level at which procedure definitions
69 				   may be found, -1 if none currently valid
70 				   (meaningful only if l_prclevel is true) */
71 char	*defsfile = "/usr/lib/vgrindefs";	/* name of language definitions file */
72 char	pname[BUFSIZ+1];
73 
74 /*
75  *	The language specific globals
76  */
77 
78 char	*language = "c";	/* the language indicator */
79 char	*l_keywds[BUFSIZ/2];	/* keyword table address */
80 char	*l_prcbeg;		/* regular expr for procedure begin */
81 char	*l_combeg;		/* string introducing a comment */
82 char	*l_comend;		/* string ending a comment */
83 char	*l_acmbeg;		/* string introducing a comment */
84 char	*l_acmend;		/* string ending a comment */
85 char	*l_blkbeg;		/* string begining of a block */
86 char	*l_blkend;		/* string ending a block */
87 char	*l_strbeg;		/* delimiter for string constant */
88 char	*l_strend;		/* delimiter for string constant */
89 char	*l_chrbeg;		/* delimiter for character constant */
90 char	*l_chrend;		/* delimiter for character constant */
91 char	*l_prcenable;		/* re indicating that procedure definitions
92 				   can be found in the next lexical level --
93 				   kludge for lisp-like languages that use
94 				   something like
95 					   (defun (proc ...)
96 					  	(proc ...)
97 					   )
98 				   to define procedures */
99 char	l_escape;		/* character used to  escape characters */
100 boolean	l_toplex;		/* procedures only defined at top lex level */
101 boolean l_prclevel;		/* procedure definitions valid only within
102 				   the nesting level indicated by the px
103 				   (l_prcenable) capability */
104 
105 /*
106  *  for the benefit of die-hards who aren't convinced that tabs
107  *  occur every eight columns
108  */
109 short tabsize = 8;
110 
111 /*
112  *  global variables also used by expmatch
113  */
114 boolean	_escaped;		/* if last character was an escape */
115 char	*Start;			/* start of the current string */
116 boolean	l_onecase;		/* upper and lower case are equivalent */
117 char	*l_idchars;		/* characters legal in identifiers in addition
118 				   to letters and digits (default "_") */
119 
120 static void putcp(int c);
121 static int width(char *s, char *os);
122 static int tabs(char *s, char *os);
123 static void putKcp(char *start, char *end, boolean force);
124 static void putScp(char *os);
125 static int iskw(char *s);
126 
127 /*
128  * The code below emits troff macros and directives that consume part of the
129  * troff macro and register space.  See tmac.vgrind for an enumeration of
130  * these macros and registers.
131  */
132 
133 int
134 main(int argc, char *argv[])
135 {
136     FILE *in;
137     char *fname;
138     struct stat stbuf;
139     char buf[BUFSIZ];
140     char idbuf[256];	/* enough for all 8 bit chars */
141     char strings[2 * BUFSIZ];
142     char defs[2 * BUFSIZ];
143     int needbp = 0;
144     int i;
145     char *cp;
146 
147 	(void) setlocale(LC_ALL, "");
148 #if !defined(TEXT_DOMAIN)
149 #define	TEXT_DOMAIN	"SYS_TEST"
150 #endif
151 	(void) textdomain(TEXT_DOMAIN);
152 
153     /*
154      * Dump the name by which we were invoked.
155      */
156     argc--, argv++;
157 
158     /*
159      * Process arguments.  For the sake of compatibility with older versions
160      * of the program, the syntax accepted below is very idiosyncratic.  Some
161      * options require space between the option and its argument; others
162      * disallow it.  No options may be bundled together.
163      *
164      * Actually, there is one incompatibility.  Files and options formerly
165      * could be arbitrarily intermixed, but this is no longer allowed.  (This
166      * possiblity was never documented.)
167      */
168     while (argc > 0 && *argv[0] == '-') {
169 	switch (*(cp = argv[0] + 1)) {
170 
171 	case '\0':				/* - */
172 	    /* Take input from stdin. */
173 	    /*
174 	     * This option implies the end of the flag arguments.  Leave the
175 	     * "-" in place for the file processing code to see.
176 	     */
177 	    goto flagsdone;
178 
179 	case '2':				/* -2 */
180 	    /* Enter two column mode. */
181 	    twocol = 1;
182 	    printf("'nr =2 1\n");
183 	    break;
184 
185 	case 'd':				/* -d <defs-file> */
186 	    /* Specify the language description file. */
187 	    defsfile = argv[1];
188 	    argc--, argv++;
189 	    break;
190 
191 	case 'f':				/* -f */
192 	    /* Act as a filter like eqn. */
193 	    filter = 1;
194 	    /*
195 	     * Slide remaining arguments down one position and postpend "-",
196 	     * to force reading from stdin.
197 	     */
198 	    for (i = 0; i < argc - 1; i++)
199 		argv[i] = argv[i + 1];
200 	    argv[argc - 1] = "-";
201 	    continue;
202 
203 	case 'h':				/* -h [header] */
204 	    /* Specify header string. */
205 	    if (argc == 1) {
206 		printf("'ds =H\n");
207 		break;
208 	    }
209 	    printf("'ds =H %s\n", argv[1]);
210 	    argc--, argv++;
211 	    break;
212 
213 	case 'l':				/* -l<language> */
214 	    /* Specify the language. */
215 	    language = cp + 1;
216 	    break;
217 
218 	case 'n':				/* -n */
219 	    /* Indicate no keywords. */
220 	    nokeyw = 1;
221 	    break;
222 
223 	case 's':				/* -s<size> */
224 	    /* Specify the font size. */
225 	    i = 0;
226 	    cp++;
227 	    while (*cp)
228 		i = i * 10 + (*cp++ - '0');
229 	    printf("'nr vP %d\n", i);
230 	    break;
231 
232 	case 't':				/* -t */
233 	    /* Specify a nondefault tab size. */
234 	    tabsize = 4;
235 	    break;
236 
237 	case 'x':				/* -x */
238 	    /* Build an index. */
239 	    doindex = 1;
240 	    /* This option implies "-n" as well; turn it on. */
241 	    argv[0] = "-n";
242 	    continue;
243 	}
244 
245 	/* Advance to next argument. */
246 	argc--, argv++;
247     }
248 
249 flagsdone:
250 
251     /*
252      * Get the language definition from the defs file.
253      */
254     i = tgetent (defs, language, defsfile);
255     if (i == 0) {
256 	fprintf (stderr, gettext("no entry for language %s\n"), language);
257 	exit (0);
258     } else  if (i < 0) {
259 	fprintf (stderr,  gettext("cannot find vgrindefs file %s\n"), defsfile);
260 	exit (0);
261     }
262     cp = strings;
263     if (tgetstr ("kw", &cp) == NIL)
264 	nokeyw = TRUE;
265     else  {
266 	char **cpp;
267 
268 	cpp = l_keywds;
269 	cp = strings;
270 	while (*cp) {
271 	    while (*cp == ' ' || *cp =='\t')
272 		*cp++ = NULL;
273 	    if (*cp)
274 		*cpp++ = cp;
275 	    while (*cp != ' ' && *cp  != '\t' && *cp)
276 		cp++;
277 	}
278 	*cpp = NIL;
279     }
280     cp = buf;
281     l_prcbeg = convexp (tgetstr ("pb", &cp));
282     cp = buf;
283     l_combeg = convexp (tgetstr ("cb", &cp));
284     cp = buf;
285     l_comend = convexp (tgetstr ("ce", &cp));
286     cp = buf;
287     l_acmbeg = convexp (tgetstr ("ab", &cp));
288     cp = buf;
289     l_acmend = convexp (tgetstr ("ae", &cp));
290     cp = buf;
291     l_strbeg = convexp (tgetstr ("sb", &cp));
292     cp = buf;
293     l_strend = convexp (tgetstr ("se", &cp));
294     cp = buf;
295     l_blkbeg = convexp (tgetstr ("bb", &cp));
296     cp = buf;
297     l_blkend = convexp (tgetstr ("be", &cp));
298     cp = buf;
299     l_chrbeg = convexp (tgetstr ("lb", &cp));
300     cp = buf;
301     l_chrend = convexp (tgetstr ("le", &cp));
302     cp = buf;
303     l_prcenable = convexp (tgetstr ("px", &cp));
304     cp = idbuf;
305     l_idchars = tgetstr ("id", &cp);
306     /* Set default, for compatibility with old version */
307     if (l_idchars == NIL)
308 	l_idchars = "_";
309     l_escape = '\\';
310     l_onecase = tgetflag ("oc");
311     l_toplex = tgetflag ("tl");
312     l_prclevel = tgetflag ("pl");
313 
314     /*
315      * Emit a call to the initialization macro.  If not in filter mode, emit a
316      * call to the vS macro, so that tmac.vgrind can uniformly assume that all
317      * program input is bracketed with vS-vE pairs.
318      */
319     printf("'vI\n");
320     if (!filter)
321 	printf("'vS\n");
322 
323     if (doindex) {
324 	/*
325 	 * XXX:	Hard-wired spacing information.  This should probably turn
326 	 *	into the emission of a macro invocation, so that tmac.vgrind
327 	 *	can make up its own mind about what spacing is appropriate.
328 	 */
329 	if (twocol)
330 	    printf("'ta 2.5i 2.75i 4.0iR\n'in .25i\n");
331 	else
332 	    printf("'ta 4i 4.25i 5.5iR\n'in .5i\n");
333     }
334 
335     while (argc > 0) {
336 	if (strcmp(argv[0], "-") == 0) {
337 	    /* Embed an instance of the original stdin. */
338 	    in = fdopen(fileno(stdin), "r");
339 	    fname = "";
340 	} else {
341 	    /* Open the file for input. */
342 	    if ((in = fopen(argv[0], "r")) == NULL) {
343 		perror(argv[0]);
344 		exit(1);
345 	    }
346 	    fname = argv[0];
347 	}
348 	argc--, argv++;
349 
350 	/*
351 	 * Reinitialize for the current file.
352 	 */
353 	incomm = FALSE;
354 	instr = FALSE;
355 	inchr = FALSE;
356 	_escaped = FALSE;
357 	blklevel = 0;
358 	prclevel = -1;
359 	for (psptr=0; psptr<PSMAX; psptr++) {
360 	    pstack[psptr][0] = NULL;
361 	    plstack[psptr] = 0;
362 	}
363 	psptr = -1;
364 	printf("'-F\n");
365 	if (!filter) {
366 	    char *cp;
367 
368 	    printf(".ds =F %s\n", fname);
369 	    if (needbp) {
370 		needbp = 0;
371 		printf(".()\n");
372 		printf(".bp\n");
373 	    }
374 	    fstat(fileno(in), &stbuf);
375 	    cp = ctime(&stbuf.st_mtime);
376 	    cp[16] = '\0';
377 	    cp[24] = '\0';
378 	    printf(".ds =M %s %s\n", cp+4, cp+20);
379 	    printf("'wh 0 vH\n");
380 	    printf("'wh -1i vF\n");
381 	}
382 	if (needbp && filter) {
383 	    needbp = 0;
384 	    printf(".()\n");
385 	    printf(".bp\n");
386 	}
387 
388 	/*
389 	 *	MAIN LOOP!!!
390 	 */
391 	while (fgets(buf, sizeof buf, in) != NULL) {
392 	    if (buf[0] == '\f') {
393 		printf(".bp\n");
394 	    }
395 	    if (buf[0] == '.') {
396 		printf("%s", buf);
397 		if (!strncmp (buf+1, "vS", 2))
398 		    pass = TRUE;
399 		if (!strncmp (buf+1, "vE", 2))
400 		    pass = FALSE;
401 		continue;
402 	    }
403 	    prccont = FALSE;
404 	    if (!filter || pass)
405 		putScp(buf);
406 	    else
407 		printf("%s", buf);
408 	    if (prccont && (psptr >= 0))
409 		printf("'FC %s\n", pstack[psptr]);
410 #ifdef DEBUG
411 	    printf ("com %o str %o chr %o ptr %d\n", incomm, instr, inchr, psptr);
412 #endif
413 	    margin = 0;
414 	}
415 
416 	needbp = 1;
417 	(void) fclose(in);
418     }
419 
420     /* Close off the vS-vE pair. */
421     if (!filter)
422 	printf("'vE\n");
423 
424     return (0);
425 }
426 
427 #define isidchr(c) (isalnum(c) || ((c) != NIL && strchr(l_idchars, (c)) != NIL))
428 
429 static void
430 putScp(char *os)
431 {
432     char *s = os;			/* pointer to unmatched string */
433     char dummy[BUFSIZ];			/* dummy to be used by expmatch */
434     char *comptr;			/* end of a comment delimiter */
435     char *acmptr;			/* end of a comment delimiter */
436     char *strptr;			/* end of a string delimiter */
437     char *chrptr;			/* end of a character const delimiter */
438     char *blksptr;			/* end of a lexical block start */
439     char *blkeptr;			/* end of a lexical block end */
440 
441     Start = os;			/* remember the start for expmatch */
442     _escaped = FALSE;
443     if (nokeyw || incomm || instr)
444 	goto skip;
445     if (isproc(s)) {
446 	printf("'FN %s\n", pname);
447 	if (psptr < PSMAX-1) {
448 	    ++psptr;
449 	    strncpy (pstack[psptr], pname, PNAMELEN);
450 	    pstack[psptr][PNAMELEN] = NULL;
451 	    plstack[psptr] = blklevel;
452 	}
453     }
454     /*
455      * if l_prclevel is set, check to see whether this lexical level
456      * is one immediately below which procedure definitions are allowed.
457      */
458     if (l_prclevel && !incomm && !instr && !inchr) {
459 	if (expmatch (s, l_prcenable, dummy) != NIL)
460 	    prclevel = blklevel + 1;
461     }
462 skip:
463     do {
464 	/* check for string, comment, blockstart, etc */
465 	if (!incomm && !instr && !inchr) {
466 
467 	    blkeptr = expmatch (s, l_blkend, dummy);
468 	    blksptr = expmatch (s, l_blkbeg, dummy);
469 	    comptr = expmatch (s, l_combeg, dummy);
470 	    acmptr = expmatch (s, l_acmbeg, dummy);
471 	    strptr = expmatch (s, l_strbeg, dummy);
472 	    chrptr = expmatch (s, l_chrbeg, dummy);
473 
474 	    /* start of a comment? */
475 	    if (comptr != NIL)
476 		if ((comptr < strptr || strptr == NIL)
477 		  && (comptr < acmptr || acmptr == NIL)
478 		  && (comptr < chrptr || chrptr == NIL)
479 		  && (comptr < blksptr || blksptr == NIL)
480 		  && (comptr < blkeptr || blkeptr == NIL)) {
481 		    putKcp (s, comptr-1, FALSE);
482 		    s = comptr;
483 		    incomm = TRUE;
484 		    comtype = STANDARD;
485 		    if (s != os)
486 			printf ("\\c");
487 		    printf ("\\c\n'+C\n");
488 		    continue;
489 		}
490 
491 	    /* start of a comment? */
492 	    if (acmptr != NIL)
493 		if ((acmptr < strptr || strptr == NIL)
494 		  && (acmptr < chrptr || chrptr == NIL)
495 		  && (acmptr < blksptr || blksptr == NIL)
496 		  && (acmptr < blkeptr || blkeptr == NIL)) {
497 		    putKcp (s, acmptr-1, FALSE);
498 		    s = acmptr;
499 		    incomm = TRUE;
500 		    comtype = ALTERNATE;
501 		    if (s != os)
502 			printf ("\\c");
503 		    printf ("\\c\n'+C\n");
504 		    continue;
505 		}
506 
507 	    /* start of a string? */
508 	    if (strptr != NIL)
509 		if ((strptr < chrptr || chrptr == NIL)
510 		  && (strptr < blksptr || blksptr == NIL)
511 		  && (strptr < blkeptr || blkeptr == NIL)) {
512 		    putKcp (s, strptr-1, FALSE);
513 		    s = strptr;
514 		    instr = TRUE;
515 		    continue;
516 		}
517 
518 	    /* start of a character string? */
519 	    if (chrptr != NIL)
520 		if ((chrptr < blksptr || blksptr == NIL)
521 		  && (chrptr < blkeptr || blkeptr == NIL)) {
522 		    putKcp (s, chrptr-1, FALSE);
523 		    s = chrptr;
524 		    inchr = TRUE;
525 		    continue;
526 		}
527 
528 	    /* end of a lexical block */
529 	    if (blkeptr != NIL) {
530 		if (blkeptr < blksptr || blksptr == NIL) {
531 		    /* reset prclevel if necessary */
532 		    if (l_prclevel && prclevel == blklevel)
533 			prclevel = -1;
534 		    putKcp (s, blkeptr - 1, FALSE);
535 		    s = blkeptr;
536 		    blklevel--;
537 		    if (psptr >= 0 && plstack[psptr] >= blklevel) {
538 
539 			/* end of current procedure */
540 			if (s != os)
541 			    printf ("\\c");
542 			printf ("\\c\n'-F\n");
543 			blklevel = plstack[psptr];
544 
545 			/* see if we should print the last proc name */
546 			if (--psptr >= 0)
547 			    prccont = TRUE;
548 			else
549 			    psptr = -1;
550 		    }
551 		    continue;
552 		}
553 	    }
554 
555 	    /* start of a lexical block */
556 	    if (blksptr != NIL) {
557 		putKcp (s, blksptr - 1, FALSE);
558 		s = blksptr;
559 		blklevel++;
560 		continue;
561 	    }
562 
563 	/* check for end of comment */
564 	} else if (incomm) {
565 	    comptr = expmatch (s, l_comend, dummy);
566 	    acmptr = expmatch (s, l_acmend, dummy);
567 	    if (((comtype == STANDARD) && (comptr != NIL)) ||
568 	        ((comtype == ALTERNATE) && (acmptr != NIL))) {
569 		if (comtype == STANDARD) {
570 		    putKcp (s, comptr-1, TRUE);
571 		    s = comptr;
572 		} else {
573 		    putKcp (s, acmptr-1, TRUE);
574 		    s = acmptr;
575 		}
576 		incomm = FALSE;
577 		printf("\\c\n'-C\n");
578 		continue;
579 	    } else {
580 		putKcp (s, s + strlen(s) -1, TRUE);
581 		s = s + strlen(s);
582 		continue;
583 	    }
584 
585 	/* check for end of string */
586 	} else if (instr) {
587 	    if ((strptr = expmatch (s, l_strend, dummy)) != NIL) {
588 		putKcp (s, strptr-1, TRUE);
589 		s = strptr;
590 		instr = FALSE;
591 		continue;
592 	    } else {
593 		putKcp (s, s+strlen(s)-1, TRUE);
594 		s = s + strlen(s);
595 		continue;
596 	    }
597 
598 	/* check for end of character string */
599 	} else if (inchr) {
600 	    if ((chrptr = expmatch (s, l_chrend, dummy)) != NIL) {
601 		putKcp (s, chrptr-1, TRUE);
602 		s = chrptr;
603 		inchr = FALSE;
604 		continue;
605 	    } else {
606 		putKcp (s, s+strlen(s)-1, TRUE);
607 		s = s + strlen(s);
608 		continue;
609 	    }
610 	}
611 
612 	/* print out the line */
613 	putKcp (s, s + strlen(s) -1, FALSE);
614 	s = s + strlen(s);
615     } while (*s);
616 }
617 
618 static void
619 putKcp(char *start, char *end, boolean force)
620 	/* start - start of string to write */
621 	/* end - end of string to write */
622 	/* force - true if we should force nokeyw */
623 {
624     int i;
625     int xfld = 0;
626 
627     while (start <= end) {
628 	if (doindex) {
629 	    if (*start == ' ' || *start == '\t') {
630 		if (xfld == 0)
631 		    printf("");
632 		printf("\t");
633 		xfld = 1;
634 		while (*start == ' ' || *start == '\t')
635 		    start++;
636 		continue;
637 	    }
638 	}
639 
640 	/* take care of nice tab stops */
641 	if (*start == '\t') {
642 	    while (*start == '\t')
643 		start++;
644 	    i = tabs(Start, start) - margin / tabsize;
645 	    printf ("\\h'|%dn'",
646 		    i * (tabsize == 4 ? 5 : 10) + 1 - margin % tabsize);
647 	    continue;
648 	}
649 
650 	if (!nokeyw && !force)
651 	    if (  (*start == '#'   ||  isidchr(*start))
652 	       && (start == Start || !isidchr(start[-1]))
653 	       ) {
654 		i = iskw(start);
655 		if (i > 0) {
656 		    printf("\\*(+K");
657 		    do
658 			putcp(*start++);
659 		    while (--i > 0);
660 		    printf("\\*(-K");
661 		    continue;
662 		}
663 	    }
664 
665 	putcp (*start++);
666     }
667 }
668 
669 
670 static int
671 tabs(char *s, char *os)
672 {
673 
674     return (width(s, os) / tabsize);
675 }
676 
677 static int
678 width(char *s, char *os)
679 {
680 	int i = 0;
681 	unsigned char c;
682 	int n;
683 
684 	while (s < os) {
685 		if (*s == '\t') {
686 			i = (i + tabsize) &~ (tabsize-1);
687 			s++;
688 			continue;
689 		}
690 		c = *(unsigned char *)s;
691 		if (c < ' ')
692 			i += 2, s++;
693 		else if (c >= 0200) {
694 			if ((n = mblen(s, MB_CUR_MAX)) > 0) {
695 				i += csetcol(csetno(c));
696 				s += n;
697 			} else
698 				s++;
699 		} else
700 			i++, s++;
701 	}
702 	return (i);
703 }
704 
705 static void
706 putcp(int c)
707 {
708 
709 	switch(c) {
710 
711 	case 0:
712 		break;
713 
714 	case '\f':
715 		break;
716 
717 	case '{':
718 		printf("\\*(+K{\\*(-K");
719 		break;
720 
721 	case '}':
722 		printf("\\*(+K}\\*(-K");
723 		break;
724 
725 	case '\\':
726 		printf("\\e");
727 		break;
728 
729 	case '_':
730 		printf("\\*_");
731 		break;
732 
733 	case '-':
734 		printf("\\*-");
735 		break;
736 
737 		/*
738 		 * The following two cases deal with the accent characters.
739 		 * If they're part of a comment, we assume that they're part
740 		 * of running text and hand them to troff as regular quote
741 		 * characters.  Otherwise, we assume they're being used as
742 		 * special characters (e.g., string delimiters) and arrange
743 		 * for troff to render them as accents.  This is an imperfect
744 		 * heuristic that produces slightly better appearance than the
745 		 * former behavior of unconditionally rendering the characters
746 		 * as accents.  (See bug 1040343.)
747 		 */
748 
749 	case '`':
750 		if (incomm)
751 			printf("`");
752 		else
753 			printf("\\`");
754 		break;
755 
756 	case '\'':
757 		if (incomm)
758 			printf("'");
759 		else
760 			printf("\\'");
761 		break;
762 
763 	case '.':
764 		printf("\\&.");
765 		break;
766 
767 		/*
768 		 * The following two cases contain special hacking
769 		 * to make C-style comments line up.  The tests aren't
770 		 * really adequate; they lead to grotesqueries such
771 		 * as italicized multiplication and division operators.
772 		 * However, the obvious test (!incomm) doesn't work,
773 		 * because incomm isn't set until after we've put out
774 		 * the comment-begin characters.  The real problem is
775 		 * that expmatch() doesn't give us enough information.
776 		 */
777 
778 	case '*':
779 		if (instr || inchr)
780 			printf("*");
781 		else
782 			printf("\\f2*\\fP");
783 		break;
784 
785 	case '/':
786 		if (instr || inchr)
787 			printf("/");
788 		else
789 			printf("\\f2\\h'\\w' 'u-\\w'/'u'/\\fP");
790 		break;
791 
792 	default:
793 		if (c < 040)
794 			putchar('^'), c |= '@';
795 	case '\t':
796 	case '\n':
797 		putchar(c);
798 	}
799 }
800 
801 /*
802  *	look for a process beginning on this line
803  */
804 boolean
805 isproc(s)
806     char *s;
807 {
808     pname[0] = NULL;
809     if (l_prclevel ? (prclevel == blklevel) : (!l_toplex || blklevel == 0))
810 	if (expmatch (s, l_prcbeg, pname) != NIL) {
811 	    return (TRUE);
812 	}
813     return (FALSE);
814 }
815 
816 
817 /*
818  * iskw - check to see if the next word is a keyword
819  *	Return its length if it is or 0 if it isn't.
820  */
821 
822 static int
823 iskw(char *s)
824 {
825 	char **ss = l_keywds;
826 	int i = 1;
827 	char *cp = s;
828 
829 	/* Get token length. */
830 	while (++cp, isidchr(*cp))
831 		i++;
832 
833 	while (cp = *ss++) {
834 		if (!STRNCMP(s,cp,i) && !isidchr(cp[i]))
835 			return (i);
836 	}
837 	return (0);
838 }
839