Annotation of src/usr.bin/less/tags.c, Revision 1.8
1.1 etheisen 1: /*
1.4 millert 2: * Copyright (C) 1984-2002 Mark Nudelman
3: *
4: * You may distribute under the terms of either the GNU General Public
5: * License or the Less License, as specified in the README file.
1.1 etheisen 6: *
1.4 millert 7: * For more information about less, or for information on how to
8: * contact the author, see the README file.
1.1 etheisen 9: */
10:
11:
12: #include "less.h"
13:
14: #define WHITESP(c) ((c)==' ' || (c)=='\t')
15:
16: public char *tags = "tags";
17:
1.4 millert 18: static int total;
19: static int curseq;
1.1 etheisen 20:
21: extern int linenums;
22: extern int sigs;
1.4 millert 23:
24: enum tag_result {
25: TAG_FOUND,
26: TAG_NOFILE,
27: TAG_NOTAG,
28: TAG_NOTYPE,
29: TAG_INTR
30: };
31:
32: /*
33: * Tag type
34: */
35: enum {
36: T_CTAGS, /* 'tags': standard and extended format (ctags) */
37: T_CTAGS_X, /* stdin: cross reference format (ctags) */
38: T_GTAGS, /* 'GTAGS': function defenition (global) */
39: T_GRTAGS, /* 'GRTAGS': function reference (global) */
40: T_GSYMS, /* 'GSYMS': other symbols (global) */
41: T_GPATH /* 'GPATH': path name (global) */
42: };
43:
44: static enum tag_result findctag();
45: static enum tag_result findgtag();
46: static char *nextgtag();
47: static char *prevgtag();
48: static POSITION ctagsearch();
49: static POSITION gtagsearch();
50: static int getentry();
51:
52: /*
53: * The list of tags generated by the last findgtag() call.
54: *
55: * Use either pattern or line number.
56: * findgtag() always uses line number, so pattern is always NULL.
57: * findctag() usually either pattern (in which case line number is 0),
58: * or line number (in which case pattern is NULL).
59: */
60: struct taglist {
61: struct tag *tl_first;
62: struct tag *tl_last;
63: };
64: #define TAG_END ((struct tag *) &taglist)
65: static struct taglist taglist = { TAG_END, TAG_END };
66: struct tag {
67: struct tag *next, *prev; /* List links */
68: char *tag_file; /* Source file containing the tag */
69: LINENUM tag_linenum; /* Appropriate line number in source file */
70: char *tag_pattern; /* Pattern used to find the tag */
71: char tag_endline; /* True if the pattern includes '$' */
72: };
73: static struct tag *curtag;
74:
75: #define TAG_INS(tp) \
76: (tp)->next = taglist.tl_first; \
77: (tp)->prev = TAG_END; \
78: taglist.tl_first->prev = (tp); \
79: taglist.tl_first = (tp);
80:
81: #define TAG_RM(tp) \
82: (tp)->next->prev = (tp)->prev; \
83: (tp)->prev->next = (tp)->next;
84:
85: /*
86: * Delete tag structures.
87: */
88: public void
89: cleantags()
90: {
91: register struct tag *tp;
92:
93: /*
94: * Delete any existing tag list.
95: * {{ Ideally, we wouldn't do this until after we know that we
96: * can load some other tag information. }}
97: */
98: while ((tp = taglist.tl_first) != TAG_END)
99: {
100: TAG_RM(tp);
101: free(tp);
102: }
103: curtag = NULL;
104: total = curseq = 0;
105: }
106:
107: /*
108: * Create a new tag entry.
109: */
110: static struct tag *
111: maketagent(name, file, linenum, pattern, endline)
112: char *name;
113: char *file;
114: LINENUM linenum;
115: char *pattern;
116: int endline;
117: {
118: register struct tag *tp;
119:
120: tp = (struct tag *) ecalloc(sizeof(struct tag), 1);
121: tp->tag_file = save(file);
122: tp->tag_linenum = linenum;
123: tp->tag_endline = endline;
124: if (pattern == NULL)
125: tp->tag_pattern = NULL;
126: else
127: tp->tag_pattern = save(pattern);
128: return (tp);
129: }
130:
131: /*
132: * Get tag mode.
133: */
134: public int
135: gettagtype()
136: {
137: int f;
138:
139: if (strcmp(tags, "GTAGS") == 0)
140: return T_GTAGS;
141: if (strcmp(tags, "GRTAGS") == 0)
142: return T_GRTAGS;
143: if (strcmp(tags, "GSYMS") == 0)
144: return T_GSYMS;
145: if (strcmp(tags, "GPATH") == 0)
146: return T_GPATH;
147: if (strcmp(tags, "-") == 0)
148: return T_CTAGS_X;
149: f = open(tags, OPEN_READ);
150: if (f >= 0)
151: {
152: close(f);
153: return T_CTAGS;
154: }
155: return T_GTAGS;
156: }
1.1 etheisen 157:
158: /*
1.4 millert 159: * Find tags in tag file.
1.1 etheisen 160: * Find a tag in the "tags" file.
1.4 millert 161: * Sets "tag_file" to the name of the file containing the tag,
1.1 etheisen 162: * and "tagpattern" to the search pattern which should be used
163: * to find the tag.
164: */
165: public void
166: findtag(tag)
1.4 millert 167: register char *tag;
168: {
169: int type = gettagtype();
170: enum tag_result result;
171:
172: if (type == T_CTAGS)
173: result = findctag(tag);
174: else
175: result = findgtag(tag, type);
176: switch (result)
177: {
178: case TAG_FOUND:
179: case TAG_INTR:
180: break;
181: case TAG_NOFILE:
182: error("No tags file", NULL_PARG);
183: break;
184: case TAG_NOTAG:
185: error("No such tag in tags file", NULL_PARG);
186: break;
187: case TAG_NOTYPE:
188: error("unknown tag type", NULL_PARG);
189: break;
190: }
191: }
192:
193: /*
194: * Search for a tag.
195: */
196: public POSITION
197: tagsearch()
198: {
199: if (curtag == NULL)
200: return (NULL_POSITION); /* No gtags loaded! */
201: if (curtag->tag_linenum != 0)
202: return gtagsearch();
203: else
204: return ctagsearch();
205: }
206:
207: /*
208: * Go to the next tag.
209: */
210: public char *
211: nexttag(n)
212: int n;
213: {
214: char *tagfile = (char *) NULL;
215:
216: while (n-- > 0)
217: tagfile = nextgtag();
218: return tagfile;
219: }
220:
221: /*
222: * Go to the previous tag.
223: */
224: public char *
225: prevtag(n)
226: int n;
227: {
228: char *tagfile = (char *) NULL;
229:
230: while (n-- > 0)
231: tagfile = prevgtag();
232: return tagfile;
233: }
234:
235: /*
236: * Return the total number of tags.
237: */
238: public int
239: ntags()
240: {
241: return total;
242: }
243:
244: /*
245: * Return the sequence number of current tag.
246: */
247: public int
248: curr_tag()
249: {
250: return curseq;
251: }
252:
253: /*****************************************************************************
254: * ctags
255: */
256:
257: /*
258: * Find tags in the "tags" file.
259: * Sets curtag to the first tag entry.
260: */
261: static enum tag_result
262: findctag(tag)
263: register char *tag;
1.1 etheisen 264: {
265: char *p;
1.4 millert 266: register FILE *f;
267: register int taglen;
268: LINENUM taglinenum;
269: char *tagfile;
270: char *tagpattern;
271: int tagendline;
1.1 etheisen 272: int search_char;
273: int err;
1.4 millert 274: char tline[TAGLINE_SIZE];
275: struct tag *tp;
1.1 etheisen 276:
1.4 millert 277: p = shell_unquote(tags);
278: f = fopen(p, "r");
279: free(p);
280: if (f == NULL)
281: return TAG_NOFILE;
1.1 etheisen 282:
1.4 millert 283: cleantags();
284: total = 0;
1.1 etheisen 285: taglen = strlen(tag);
286:
287: /*
288: * Search the tags file for the desired tag.
289: */
290: while (fgets(tline, sizeof(tline), f) != NULL)
291: {
1.4 millert 292: if (tline[0] == '!')
293: /* Skip header of extended format. */
294: continue;
1.1 etheisen 295: if (strncmp(tag, tline, taglen) != 0 || !WHITESP(tline[taglen]))
296: continue;
297:
298: /*
299: * Found it.
300: * The line contains the tag, the filename and the
301: * location in the file, separated by white space.
302: * The location is either a decimal line number,
303: * or a search pattern surrounded by a pair of delimiters.
304: * Parse the line and extract these parts.
305: */
1.4 millert 306: tagpattern = NULL;
1.1 etheisen 307:
308: /*
309: * Skip over the whitespace after the tag name.
310: */
311: p = skipsp(tline+taglen);
312: if (*p == '\0')
313: /* File name is missing! */
314: continue;
315:
316: /*
317: * Save the file name.
318: * Skip over the whitespace after the file name.
319: */
320: tagfile = p;
321: while (!WHITESP(*p) && *p != '\0')
322: p++;
323: *p++ = '\0';
324: p = skipsp(p);
325: if (*p == '\0')
326: /* Pattern is missing! */
327: continue;
328:
329: /*
330: * First see if it is a line number.
331: */
1.4 millert 332: tagendline = 0;
1.1 etheisen 333: taglinenum = getnum(&p, 0, &err);
334: if (err)
335: {
336: /*
337: * No, it must be a pattern.
338: * Delete the initial "^" (if present) and
339: * the final "$" from the pattern.
340: * Delete any backslash in the pattern.
341: */
342: taglinenum = 0;
343: search_char = *p++;
344: if (*p == '^')
345: p++;
1.4 millert 346: tagpattern = p;
1.1 etheisen 347: while (*p != search_char && *p != '\0')
348: {
349: if (*p == '\\')
350: p++;
1.4 millert 351: p++;
1.1 etheisen 352: }
1.4 millert 353: tagendline = (p[-1] == '$');
354: if (tagendline)
355: p--;
356: *p = '\0';
1.1 etheisen 357: }
1.4 millert 358: tp = maketagent(tag, tagfile, taglinenum, tagpattern, tagendline);
359: TAG_INS(tp);
360: total++;
1.1 etheisen 361: }
362: fclose(f);
1.4 millert 363: if (total == 0)
364: return TAG_NOTAG;
365: curtag = taglist.tl_first;
366: curseq = 1;
367: return TAG_FOUND;
368: }
369:
370: /*
371: * Edit current tagged file.
372: */
373: public int
374: edit_tagfile()
375: {
376: if (curtag == NULL)
377: return (1);
378: return (edit(curtag->tag_file));
1.1 etheisen 379: }
380:
381: /*
382: * Search for a tag.
383: * This is a stripped-down version of search().
384: * We don't use search() for several reasons:
385: * - We don't want to blow away any search string we may have saved.
386: * - The various regular-expression functions (from different systems:
387: * regcmp vs. re_comp) behave differently in the presence of
388: * parentheses (which are almost always found in a tag).
389: */
1.4 millert 390: static POSITION
391: ctagsearch()
1.1 etheisen 392: {
393: POSITION pos, linepos;
1.4 millert 394: LINENUM linenum;
395: int len;
1.1 etheisen 396: char *line;
397:
398: pos = ch_zero();
399: linenum = find_linenum(pos);
400:
401: for (;;)
402: {
403: /*
404: * Get lines until we find a matching one or
405: * until we hit end-of-file.
406: */
407: if (ABORT_SIGS())
408: return (NULL_POSITION);
409:
410: /*
411: * Read the next line, and save the
412: * starting position of that line in linepos.
413: */
414: linepos = pos;
415: pos = forw_raw_line(pos, &line);
416: if (linenum != 0)
417: linenum++;
418:
419: if (pos == NULL_POSITION)
420: {
421: /*
422: * We hit EOF without a match.
423: */
424: error("Tag not found", NULL_PARG);
425: return (NULL_POSITION);
426: }
427:
428: /*
429: * If we're using line numbers, we might as well
430: * remember the information we have now (the position
431: * and line number of the current line).
432: */
433: if (linenums)
434: add_lnum(linenum, pos);
435:
436: /*
437: * Test the line to see if we have a match.
438: * Use strncmp because the pattern may be
439: * truncated (in the tags file) if it is too long.
1.4 millert 440: * If tagendline is set, make sure we match all
441: * the way to end of line (no extra chars after the match).
1.1 etheisen 442: */
1.4 millert 443: len = strlen(curtag->tag_pattern);
444: if (strncmp(curtag->tag_pattern, line, len) == 0 &&
445: (!curtag->tag_endline || line[len] == '\0' || line[len] == '\r'))
446: {
447: curtag->tag_linenum = find_linenum(linepos);
1.1 etheisen 448: break;
1.4 millert 449: }
1.1 etheisen 450: }
451:
452: return (linepos);
453: }
454:
1.4 millert 455: /*******************************************************************************
456: * gtags
457: */
458:
459: /*
460: * Find tags in the GLOBAL's tag file.
461: * The findgtag() will try and load information about the requested tag.
462: * It does this by calling "global -x tag" and storing the parsed output
463: * for future use by gtagsearch().
464: * Sets curtag to the first tag entry.
465: */
466: static enum tag_result
467: findgtag(tag, type)
468: char *tag; /* tag to load */
469: int type; /* tags type */
470: {
471: char buf[256];
472: FILE *fp;
473: struct tag *tp;
474:
475: if (type != T_CTAGS_X && tag == NULL)
476: return TAG_NOFILE;
477:
478: cleantags();
479: total = 0;
480:
481: /*
482: * If type == T_CTAGS_X then read ctags's -x format from stdin
483: * else execute global(1) and read from it.
484: */
485: if (type == T_CTAGS_X)
486: {
487: fp = stdin;
488: /* Set tag default because we cannot read stdin again. */
489: tags = "tags";
490: } else
491: {
492: #if !HAVE_POPEN
493: return TAG_NOFILE;
494: #else
495: char command[512];
496: char *flag;
497: char *qtag;
498: char *cmd = lgetenv("LESSGLOBALTAGS");
499:
500: if (cmd == NULL || *cmd == '\0')
501: return TAG_NOFILE;
502: /* Get suitable flag value for global(1). */
503: switch (type)
504: {
505: case T_GTAGS:
506: flag = "" ;
507: break;
508: case T_GRTAGS:
509: flag = "r";
510: break;
511: case T_GSYMS:
512: flag = "s";
513: break;
514: case T_GPATH:
515: flag = "P";
516: break;
517: default:
518: return TAG_NOTYPE;
519: }
520:
521: /* Get our data from global(1). */
522: qtag = shell_quote(tag);
523: if (qtag == NULL)
524: qtag = tag;
525: snprintf(command, sizeof(command), "%s -x%s %s", cmd,
526: flag, qtag);
527: if (qtag != tag)
528: free(qtag);
529: fp = popen(command, "r");
530: #endif
531: }
532: if (fp != NULL)
533: {
534: while (fgets(buf, sizeof(buf), fp))
535: {
536: char *name, *file, *line;
1.6 cloder 537: size_t len;
1.4 millert 538:
539: if (sigs)
540: {
541: #if HAVE_POPEN
542: if (fp != stdin)
543: pclose(fp);
544: #endif
545: return TAG_INTR;
546: }
1.6 cloder 547: if ((len = strlen(buf)) && buf[len - 1] == '\n')
548: buf[len - 1] = 0;
1.4 millert 549: else
550: {
551: int c;
552: do {
553: c = fgetc(fp);
554: } while (c != '\n' && c != EOF);
555: }
556:
557: if (getentry(buf, &name, &file, &line))
558: {
559: /*
560: * Couldn't parse this line for some reason.
561: * We'll just pretend it never happened.
562: */
563: break;
564: }
565:
566: /* Make new entry and add to list. */
567: tp = maketagent(name, file, (LINENUM) atoi(line), NULL, 0);
568: TAG_INS(tp);
569: total++;
570: }
571: if (fp != stdin)
572: {
573: if (pclose(fp))
574: {
575: curtag = NULL;
576: total = curseq = 0;
577: return TAG_NOFILE;
578: }
579: }
580: }
581:
582: /* Check to see if we found anything. */
583: tp = taglist.tl_first;
584: if (tp == TAG_END)
585: return TAG_NOTAG;
586: curtag = tp;
587: curseq = 1;
588: return TAG_FOUND;
589: }
590:
591: static int circular = 0; /* 1: circular tag structure */
592:
593: /*
594: * Return the filename required for the next gtag in the queue that was setup
595: * by findgtag(). The next call to gtagsearch() will try to position at the
596: * appropriate tag.
597: */
598: static char *
599: nextgtag()
600: {
601: struct tag *tp;
602:
603: if (curtag == NULL)
604: /* No tag loaded */
605: return NULL;
606:
607: tp = curtag->next;
608: if (tp == TAG_END)
609: {
610: if (!circular)
611: return NULL;
612: /* Wrapped around to the head of the queue */
613: curtag = taglist.tl_first;
614: curseq = 1;
615: } else
616: {
617: curtag = tp;
618: curseq++;
619: }
620: return (curtag->tag_file);
621: }
622:
623: /*
624: * Return the filename required for the previous gtag in the queue that was
625: * setup by findgtat(). The next call to gtagsearch() will try to position
626: * at the appropriate tag.
627: */
628: static char *
629: prevgtag()
630: {
631: struct tag *tp;
632:
633: if (curtag == NULL)
634: /* No tag loaded */
635: return NULL;
636:
637: tp = curtag->prev;
638: if (tp == TAG_END)
639: {
640: if (!circular)
641: return NULL;
642: /* Wrapped around to the tail of the queue */
643: curtag = taglist.tl_last;
644: curseq = total;
645: } else
646: {
647: curtag = tp;
648: curseq--;
649: }
650: return (curtag->tag_file);
651: }
652:
653: /*
654: * Position the current file at at what is hopefully the tag that was chosen
655: * using either findtag() or one of nextgtag() and prevgtag(). Returns -1
1.5 jmc 656: * if it was unable to position at the tag, 0 if successful.
1.4 millert 657: */
658: static POSITION
659: gtagsearch()
660: {
661: if (curtag == NULL)
662: return (NULL_POSITION); /* No gtags loaded! */
663: return (find_pos(curtag->tag_linenum));
664: }
665:
666: /*
667: * The getentry() parses both standard and extended ctags -x format.
668: *
669: * [standard format]
670: * <tag> <lineno> <file> <image>
671: * +------------------------------------------------
672: * |main 30 main.c main(argc, argv)
673: * |func 21 subr.c func(arg)
674: *
675: * The following commands write this format.
676: * o Traditinal Ctags with -x option
677: * o Global with -x option
678: * See <http://www.gnu.org/software/global/global.html>
679: *
680: * [extended format]
681: * <tag> <type> <lineno> <file> <image>
682: * +----------------------------------------------------------
683: * |main function 30 main.c main(argc, argv)
684: * |func function 21 subr.c func(arg)
685: *
686: * The following commands write this format.
687: * o Exuberant Ctags with -x option
688: * See <http://ctags.sourceforge.net>
689: *
690: * Returns 0 on success, -1 on error.
691: * The tag, file, and line will each be NUL-terminated pointers
692: * into buf.
693: */
694:
695: #ifndef isspace
696: #define isspace(c) ((c) == ' ' || (c) == '\t' || (c) == '\n' || (c) == '\r' || (c) == '\f')
697: #endif
698: #ifndef isdigit
699: #define isdigit(c) ((c) >= '0' && (c <= '9'))
700: #endif
701:
702: static int
703: getentry(buf, tag, file, line)
704: char *buf; /* standard or extended ctags -x format data */
705: char **tag; /* name of the tag we actually found */
706: char **file; /* file in which to find this tag */
707: char **line; /* line number of file where this tag is found */
708: {
709: char *p = buf;
710:
711: for (*tag = p; *p && !isspace(*p); p++) /* tag name */
712: ;
713: if (*p == 0)
714: return (-1);
715: *p++ = 0;
1.7 tedu 716: for ( ; isspace(*p); p++) /* (skip blanks) */
1.4 millert 717: ;
718: if (*p == 0)
719: return (-1);
720: /*
721: * If the second part begin with other than digit,
722: * it is assumed tag type. Skip it.
723: */
724: if (!isdigit(*p))
725: {
726: for ( ; *p && !isspace(*p); p++) /* (skip tag type) */
727: ;
1.7 tedu 728: for (; isspace(*p); p++) /* (skip blanks) */
1.4 millert 729: ;
730: }
731: if (!isdigit(*p))
732: return (-1);
733: *line = p; /* line number */
734: for (*line = p; *p && !isspace(*p); p++)
735: ;
736: if (*p == 0)
737: return (-1);
738: *p++ = 0;
1.7 tedu 739: for ( ; isspace(*p); p++) /* (skip blanks) */
1.4 millert 740: ;
741: if (*p == 0)
742: return (-1);
743: *file = p; /* file name */
744: for (*file = p; *p && !isspace(*p); p++)
745: ;
746: if (*p == 0)
747: return (-1);
748: *p = 0;
749:
750: /* value check */
751: if (strlen(*tag) && strlen(*line) && strlen(*file) && atoi(*line) > 0)
752: return (0);
753: return (-1);
754: }
1.8 ! guenther 755: