ex/ex_tag.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * David Hitz of Auspex Systems, Inc.
   9  *
  10  * See the LICENSE file for redistribution information.
  11  */
  12
  13 #include "config.h"
  14
  15 #ifndef lint
  16 static const char sccsid[] = "$Id: ex_tag.c,v 10.48 2001/06/25 15:19:20 skimo Exp $ (Berkeley) $Date: 2001/06/25 15:19:20 $";
  17 #endif /* not lint */
  18
  19 #include <sys/param.h>
  20 #include <sys/types.h>          /* XXX: param.h may not have included types.h */
  21
  22 #ifdef HAVE_SYS_MMAN_H
  23 #include <sys/mman.h>
  24 #endif
  25
  26 #include <sys/queue.h>
  27 #include <sys/stat.h>
  28 #include <sys/time.h>
  29
  30 #include <bitstring.h>
  31 #include <ctype.h>
  32 #include <errno.h>
  33 #include <fcntl.h>
  34 #include <limits.h>
  35 #include <stddef.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40
  41 #include "../common/common.h"
  42 #include "../vi/vi.h"
  43 #include "tag.h"
  44
  45 static char     *binary_search __P((char *, char *, char *));
  46 static int       compare __P((char *, char *, char *));
  47 static void      ctag_file __P((SCR *, TAGF *, char *, char **, size_t *));
  48 static int       ctag_search __P((SCR *, CHAR_T *, size_t, char *));
  49 static int       ctag_sfile __P((SCR *, TAGF *, TAGQ *, char *));
  50 static TAGQ     *ctag_slist __P((SCR *, CHAR_T *));
  51 static char     *linear_search __P((char *, char *, char *));
  52 static int       tag_copy __P((SCR *, TAG *, TAG **));
  53 static int       tag_pop __P((SCR *, TAGQ *, int));
  54 static int       tagf_copy __P((SCR *, TAGF *, TAGF **));
  55 static int       tagf_free __P((SCR *, TAGF *));
  56 static int       tagq_copy __P((SCR *, TAGQ *, TAGQ **));
  57
  58 /*
  59  * ex_tag_first --
  60  *      The tag code can be entered from main, e.g., "vi -t tag".
  61  *
  62  * PUBLIC: int ex_tag_first __P((SCR *, CHAR_T *));
  63  */
  64 int
  65 ex_tag_first(SCR *sp, CHAR_T *tagarg)
  66 {
  67         EXCMD cmd;
  68
  69         /* Build an argument for the ex :tag command. */
  70         ex_cinit(sp, &cmd, C_TAG, 0, OOBLNO, OOBLNO, 0);
  71         argv_exp0(sp, &cmd, tagarg, STRLEN(tagarg));
  72
  73         /*
  74          * XXX
  75          * Historic vi went ahead and created a temporary file when it failed
  76          * to find the tag.  We match historic practice, but don't distinguish
  77          * between real error and failure to find the tag.
  78          */
  79         if (ex_tag_push(sp, &cmd))
  80                 return (0);
  81
  82         /* Display tags in the center of the screen. */
  83         F_CLR(sp, SC_SCR_TOP);
  84         F_SET(sp, SC_SCR_CENTER);
  85
  86         return (0);
  87 }
  88
  89 /*
  90  * ex_tag_push -- ^]
  91  *                :tag[!] [string]
  92  *
  93  * Enter a new TAGQ context based on a ctag string.
  94  *
  95  * PUBLIC: int ex_tag_push __P((SCR *, EXCMD *));
  96  */
  97 int
  98 ex_tag_push(SCR *sp, EXCMD *cmdp)
  99 {
 100         EX_PRIVATE *exp;
 101         TAGQ *tqp;
 102         long tl;
 103
 104         exp = EXP(sp);
 105         switch (cmdp->argc) {
 106         case 1:
 107                 if (exp->tag_last != NULL)
 108                         free(exp->tag_last);
 109
 110                 if ((exp->tag_last = v_wstrdup(sp, cmdp->argv[0]->bp,
 111                     cmdp->argv[0]->len)) == NULL) {
 112                         msgq(sp, M_SYSERR, NULL);
 113                         return (1);
 114                 }
 115
 116                 /* Taglength may limit the number of characters. */
 117                 if ((tl =
 118                     O_VAL(sp, O_TAGLENGTH)) != 0 && STRLEN(exp->tag_last) > tl)
 119                         exp->tag_last[tl] = '\0';
 120                 break;
 121         case 0:
 122                 if (exp->tag_last == NULL) {
 123                         msgq(sp, M_ERR, "158|No previous tag entered");
 124                         return (1);
 125                 }
 126                 break;
 127         default:
 128                 abort();
 129         }
 130
 131         /* Get the tag information. */
 132         if ((tqp = ctag_slist(sp, exp->tag_last)) == NULL)
 133                 return (1);
 134
 135         if (tagq_push(sp, tqp, F_ISSET(cmdp, E_NEWSCREEN),
 136                                FL_ISSET(cmdp->iflags, E_C_FORCE)))
 137                 return 1;
 138
 139         return 0;
 140 }
 141
 142 /*
 143  * ex_tag_next --
 144  *      Switch context to the next TAG.
 145  *
 146  * PUBLIC: int ex_tag_next __P((SCR *, EXCMD *));
 147  */
 148 int
 149 ex_tag_next(SCR *sp, EXCMD *cmdp)
 150 {
 151         EX_PRIVATE *exp;
 152         TAG *tp;
 153         TAGQ *tqp;
 154         char *np;
 155         size_t nlen;
 156
 157         exp = EXP(sp);
 158         if ((tqp = exp->tq.cqh_first) == (void *)&exp->tq) {
 159                 tag_msg(sp, TAG_EMPTY, NULL);
 160                 return (1);
 161         }
 162         if ((tp = tqp->current->q.cqe_next) == (void *)&tqp->tagq) {
 163                 msgq(sp, M_ERR, "282|Already at the last tag of this group");
 164                 return (1);
 165         }
 166         if (ex_tag_nswitch(sp, tp, FL_ISSET(cmdp->iflags, E_C_FORCE)))
 167                 return (1);
 168         tqp->current = tp;
 169
 170         if (F_ISSET(tqp, TAG_CSCOPE))
 171                 (void)cscope_search(sp, tqp, tp);
 172         else
 173                 (void)ctag_search(sp, tp->search, tp->slen, tqp->tag);
 174         if (tqp->current->msg) {
 175             INT2CHAR(sp, tqp->current->msg, tqp->current->mlen + 1,
 176                      np, nlen);
 177             msgq(sp, M_INFO, np);
 178         }
 179         return (0);
 180 }
 181
 182 /*
 183  * ex_tag_prev --
 184  *      Switch context to the next TAG.
 185  *
 186  * PUBLIC: int ex_tag_prev __P((SCR *, EXCMD *));
 187  */
 188 int
 189 ex_tag_prev(SCR *sp, EXCMD *cmdp)
 190 {
 191         EX_PRIVATE *exp;
 192         TAG *tp;
 193         TAGQ *tqp;
 194         char *np;
 195         size_t nlen;
 196
 197         exp = EXP(sp);
 198         if ((tqp = exp->tq.cqh_first) == (void *)&exp->tq) {
 199                 tag_msg(sp, TAG_EMPTY, NULL);
 200                 return (0);
 201         }
 202         if ((tp = tqp->current->q.cqe_prev) == (void *)&tqp->tagq) {
 203                 msgq(sp, M_ERR, "255|Already at the first tag of this group");
 204                 return (1);
 205         }
 206         if (ex_tag_nswitch(sp, tp, FL_ISSET(cmdp->iflags, E_C_FORCE)))
 207                 return (1);
 208         tqp->current = tp;
 209
 210         if (F_ISSET(tqp, TAG_CSCOPE))
 211                 (void)cscope_search(sp, tqp, tp);
 212         else
 213                 (void)ctag_search(sp, tp->search, tp->slen, tqp->tag);
 214         if (tqp->current->msg) {
 215             INT2CHAR(sp, tqp->current->msg, tqp->current->mlen + 1,
 216                      np, nlen);
 217             msgq(sp, M_INFO, np);
 218         }
 219         return (0);
 220 }
 221
 222 /*
 223  * ex_tag_nswitch --
 224  *      Switch context to the specified TAG.
 225  *
 226  * PUBLIC: int ex_tag_nswitch __P((SCR *, TAG *, int));
 227  */
 228 int
 229 ex_tag_nswitch(SCR *sp, TAG *tp, int force)
 230 {
 231         /* Get a file structure. */
 232         if (tp->frp == NULL && (tp->frp = file_add(sp, tp->fname)) == NULL)
 233                 return (1);
 234
 235         /* If not changing files, return, we're done. */
 236         if (tp->frp == sp->frp)
 237                 return (0);
 238
 239         /* Check for permission to leave. */
 240         if (file_m1(sp, force, FS_ALL | FS_POSSIBLE))
 241                 return (1);
 242
 243         /* Initialize the new file. */
 244         if (file_init(sp, tp->frp, NULL, FS_SETALT))
 245                 return (1);
 246
 247         /* Display tags in the center of the screen. */
 248         F_CLR(sp, SC_SCR_TOP);
 249         F_SET(sp, SC_SCR_CENTER);
 250
 251         /* Switch. */
 252         F_SET(sp, SC_FSWITCH);
 253         return (0);
 254 }
 255
 256 /*
 257  * ex_tag_Nswitch --
 258  *      Switch context to the specified TAG in a new screen.
 259  *
 260  * PUBLIC: int ex_tag_Nswitch __P((SCR *, TAG *, int));
 261  */
 262 int
 263 ex_tag_Nswitch(SCR *sp, TAG *tp, int force)
 264 {
 265         SCR *new;
 266
 267         /* Get a file structure. */
 268         if (tp->frp == NULL && (tp->frp = file_add(sp, tp->fname)) == NULL)
 269                 return (1);
 270
 271         /* Get a new screen. */
 272         if (screen_init(sp->gp, sp, &new))
 273                 return (1);
 274         if (vs_split(sp, new, 0)) {
 275                 (void)file_end(new, new->ep, 1);
 276                 (void)screen_end(new);
 277                 return (1);
 278         }
 279
 280         /* Get a backing file. */
 281         if (tp->frp == sp->frp) {
 282                 /* Copy file state. */
 283                 new->ep = sp->ep;
 284                 ++new->ep->refcnt;
 285
 286                 new->frp = tp->frp;
 287                 new->frp->flags = sp->frp->flags;
 288         } else if (file_init(new, tp->frp, NULL, force)) {
 289                 (void)vs_discard(new, NULL);
 290                 (void)screen_end(new);
 291                 return (1);
 292         }
 293
 294         /* Create the argument list. */
 295         new->cargv = new->argv = ex_buildargv(sp, NULL, tp->frp->name);
 296
 297         /* Display tags in the center of the screen. */
 298         F_CLR(new, SC_SCR_TOP);
 299         F_SET(new, SC_SCR_CENTER);
 300
 301         /* Switch. */
 302         sp->nextdisp = new;
 303         F_SET(sp, SC_SSWITCH);
 304
 305         return (0);
 306 }
 307
 308 /*
 309  * ex_tag_pop -- ^T
 310  *               :tagp[op][!] [number | file]
 311  *
 312  *      Pop to a previous TAGQ context.
 313  *
 314  * PUBLIC: int ex_tag_pop __P((SCR *, EXCMD *));
 315  */
 316 int
 317 ex_tag_pop(SCR *sp, EXCMD *cmdp)
 318 {
 319         EX_PRIVATE *exp;
 320         TAGQ *tqp, *dtqp;
 321         size_t arglen;
 322         long off;
 323         char *arg, *p, *t;
 324         size_t nlen;
 325
 326         /* Check for an empty stack. */
 327         exp = EXP(sp);
 328         if (exp->tq.cqh_first == (void *)&exp->tq) {
 329                 tag_msg(sp, TAG_EMPTY, NULL);
 330                 return (1);
 331         }
 332
 333         /* Find the last TAG structure that we're going to DISCARD! */
 334         switch (cmdp->argc) {
 335         case 0:                         /* Pop one tag. */
 336                 dtqp = exp->tq.cqh_first;
 337                 break;
 338         case 1:                         /* Name or number. */
 339                 INT2CHAR(sp, cmdp->argv[0]->bp, cmdp->argv[0]->len+1,
 340                          arg, nlen);
 341                 off = strtol(arg, &p, 10);
 342                 if (*p != '\0')
 343                         goto filearg;
 344
 345                 /* Number: pop that many queue entries. */
 346                 if (off < 1)
 347                         return (0);
 348                 for (tqp = exp->tq.cqh_first;
 349                     tqp != (void *)&exp->tq && --off > 1;
 350                     tqp = tqp->q.cqe_next);
 351                 if (tqp == (void *)&exp->tq) {
 352                         msgq(sp, M_ERR,
 353         "159|Less than %s entries on the tags stack; use :display t[ags]",
 354                             arg);
 355                         return (1);
 356                 }
 357                 dtqp = tqp;
 358                 break;
 359
 360                 /* File argument: pop to that queue entry. */
 361 filearg:        arglen = strlen(arg);
 362                 for (tqp = exp->tq.cqh_first;
 363                     tqp != (void *)&exp->tq;
 364                     dtqp = tqp, tqp = tqp->q.cqe_next) {
 365                         /* Don't pop to the current file. */
 366                         if (tqp == exp->tq.cqh_first)
 367                                 continue;
 368                         p = tqp->current->frp->name;
 369                         if ((t = strrchr(p, '/')) == NULL)
 370                                 t = p;
 371                         else
 372                                 ++t;
 373                         if (!strncmp(arg, t, arglen))
 374                                 break;
 375                 }
 376                 if (tqp == (void *)&exp->tq) {
 377                         msgq_str(sp, M_ERR, arg,
 378         "160|No file %s on the tags stack to return to; use :display t[ags]");
 379                         return (1);
 380                 }
 381                 if (tqp == exp->tq.cqh_first)
 382                         return (0);
 383                 break;
 384         default:
 385                 abort();
 386         }
 387
 388         return (tag_pop(sp, dtqp, FL_ISSET(cmdp->iflags, E_C_FORCE)));
 389 }
 390
 391 /*
 392  * ex_tag_top -- :tagt[op][!]
 393  *      Clear the tag stack.
 394  *
 395  * PUBLIC: int ex_tag_top __P((SCR *, EXCMD *));
 396  */
 397 int
 398 ex_tag_top(SCR *sp, EXCMD *cmdp)
 399 {
 400         EX_PRIVATE *exp;
 401
 402         exp = EXP(sp);
 403
 404         /* Check for an empty stack. */
 405         if (exp->tq.cqh_first == (void *)&exp->tq) {
 406                 tag_msg(sp, TAG_EMPTY, NULL);
 407                 return (1);
 408         }
 409
 410         /* Return to the oldest information. */
 411         return (tag_pop(sp,
 412             exp->tq.cqh_last->q.cqe_prev, FL_ISSET(cmdp->iflags, E_C_FORCE)));
 413 }
 414
 415 /*
 416  * tag_pop --
 417  *      Pop up to and including the specified TAGQ context.
 418  */
 419 static int
 420 tag_pop(SCR *sp, TAGQ *dtqp, int force)
 421 {
 422         EX_PRIVATE *exp;
 423         TAG *tp;
 424         TAGQ *tqp;
 425
 426         exp = EXP(sp);
 427
 428         /*
 429          * Update the cursor from the saved TAG information of the TAG
 430          * structure we're moving to.
 431          */
 432         tp = dtqp->q.cqe_next->current;
 433         if (tp->frp == sp->frp) {
 434                 sp->lno = tp->lno;
 435                 sp->cno = tp->cno;
 436         } else {
 437                 if (file_m1(sp, force, FS_ALL | FS_POSSIBLE))
 438                         return (1);
 439
 440                 tp->frp->lno = tp->lno;
 441                 tp->frp->cno = tp->cno;
 442                 F_SET(sp->frp, FR_CURSORSET);
 443                 if (file_init(sp, tp->frp, NULL, FS_SETALT))
 444                         return (1);
 445
 446                 F_SET(sp, SC_FSWITCH);
 447         }
 448
 449         /* Pop entries off the queue up to and including dtqp. */
 450         do {
 451                 tqp = exp->tq.cqh_first;
 452                 if (tagq_free(sp, tqp))
 453                         return (0);
 454         } while (tqp != dtqp);
 455
 456         /*
 457          * If only a single tag left, we've returned to the first tag point,
 458          * and the stack is now empty.
 459          */
 460         if (exp->tq.cqh_first->q.cqe_next == (void *)&exp->tq)
 461                 tagq_free(sp, exp->tq.cqh_first);
 462
 463         return (0);
 464 }
 465
 466 /*
 467  * ex_tag_display --
 468  *      Display the list of tags.
 469  *
 470  * PUBLIC: int ex_tag_display __P((SCR *));
 471  */
 472 int
 473 ex_tag_display(SCR *sp)
 474 {
 475         EX_PRIVATE *exp;
 476         TAG *tp;
 477         TAGQ *tqp;
 478         int cnt;
 479         size_t len;
 480         char *p;
 481
 482         exp = EXP(sp);
 483         if ((tqp = exp->tq.cqh_first) == (void *)&exp->tq) {
 484                 tag_msg(sp, TAG_EMPTY, NULL);
 485                 return (0);
 486         }
 487
 488         /*
 489          * We give the file name 20 columns and the search string the rest.
 490          * If there's not enough room, we don't do anything special, it's
 491          * not worth the effort, it just makes the display more confusing.
 492          *
 493          * We also assume that characters in file names map 1-1 to printing
 494          * characters.  This might not be true, but I don't think it's worth
 495          * fixing.  (The obvious fix is to pass the filenames through the
 496          * msg_print function.)
 497          */
 498 #define L_NAME  30              /* Name. */
 499 #define L_SLOP   4              /* Leading number plus trailing *. */
 500 #define L_SPACE  5              /* Spaces after name, before tag. */
 501 #define L_TAG   20              /* Tag. */
 502         if (sp->cols <= L_NAME + L_SLOP) {
 503                 msgq(sp, M_ERR, "292|Display too small.");
 504                 return (0);
 505         }
 506
 507         /*
 508          * Display the list of tags for each queue entry.  The first entry
 509          * is numbered, and the current tag entry has an asterisk appended.
 510          */
 511         for (cnt = 1, tqp = exp->tq.cqh_first; !INTERRUPTED(sp) &&
 512             tqp != (void *)&exp->tq; ++cnt, tqp = tqp->q.cqe_next)
 513                 for (tp = tqp->tagq.cqh_first;
 514                     tp != (void *)&tqp->tagq; tp = tp->q.cqe_next) {
 515                         if (tp == tqp->tagq.cqh_first)
 516                                 (void)ex_printf(sp, "%2d ", cnt);
 517                         else
 518                                 (void)ex_printf(sp, "   ");
 519                         p = tp->frp == NULL ? tp->fname : tp->frp->name;
 520                         if ((len = strlen(p)) > L_NAME) {
 521                                 len = len - (L_NAME - 4);
 522                                 (void)ex_printf(sp, "   ... %*.*s",
 523                                     L_NAME - 4, L_NAME - 4, p + len);
 524                         } else
 525                                 (void)ex_printf(sp,
 526                                     "   %*.*s", L_NAME, L_NAME, p);
 527                         if (tqp->current == tp)
 528                                 (void)ex_printf(sp, "*");
 529
 530                         if (tp == tqp->tagq.cqh_first && tqp->tag != NULL &&
 531                             (sp->cols - L_NAME) >= L_TAG + L_SPACE) {
 532                                 len = strlen(tqp->tag);
 533                                 if (len > sp->cols - (L_NAME + L_SPACE))
 534                                         len = sp->cols - (L_NAME + L_SPACE);
 535                                 (void)ex_printf(sp, "%s%.*s",
 536                                     tqp->current == tp ? "    " : "     ",
 537                                     (int)len, tqp->tag);
 538                         }
 539                         (void)ex_printf(sp, "\n");
 540                 }
 541         return (0);
 542 }
 543
 544 /*
 545  * ex_tag_copy --
 546  *      Copy a screen's tag structures.
 547  *
 548  * PUBLIC: int ex_tag_copy __P((SCR *, SCR *));
 549  */
 550 int
 551 ex_tag_copy(SCR *orig, SCR *sp)
 552 {
 553         EX_PRIVATE *oexp, *nexp;
 554         TAGQ *aqp, *tqp;
 555         TAG *ap, *tp;
 556         TAGF *atfp, *tfp;
 557
 558         oexp = EXP(orig);
 559         nexp = EXP(sp);
 560
 561         /* Copy tag queue and tags stack. */
 562         for (aqp = oexp->tq.cqh_first;
 563             aqp != (void *)&oexp->tq; aqp = aqp->q.cqe_next) {
 564                 if (tagq_copy(sp, aqp, &tqp))
 565                         return (1);
 566                 for (ap = aqp->tagq.cqh_first;
 567                     ap != (void *)&aqp->tagq; ap = ap->q.cqe_next) {
 568                         if (tag_copy(sp, ap, &tp))
 569                                 return (1);
 570                         /* Set the current pointer. */
 571                         if (aqp->current == ap)
 572                                 tqp->current = tp;
 573                         CIRCLEQ_INSERT_TAIL(&tqp->tagq, tp, q);
 574                 }
 575                 CIRCLEQ_INSERT_TAIL(&nexp->tq, tqp, q);
 576         }
 577
 578         /* Copy list of tag files. */
 579         for (atfp = oexp->tagfq.tqh_first;
 580             atfp != NULL; atfp = atfp->q.tqe_next) {
 581                 if (tagf_copy(sp, atfp, &tfp))
 582                         return (1);
 583                 TAILQ_INSERT_TAIL(&nexp->tagfq, tfp, q);
 584         }
 585
 586         /* Copy the last tag. */
 587         if (oexp->tag_last != NULL &&
 588             (nexp->tag_last = v_wstrdup(sp, oexp->tag_last,
 589                                         STRLEN(oexp->tag_last))) == NULL) {
 590                 msgq(sp, M_SYSERR, NULL);
 591                 return (1);
 592         }
 593         return (0);
 594 }
 595
 596 /*
 597  * tagf_copy --
 598  *      Copy a TAGF structure and return it in new memory.
 599  */
 600 static int
 601 tagf_copy(SCR *sp, TAGF *otfp, TAGF **tfpp)
 602 {
 603         TAGF *tfp;
 604
 605         MALLOC_RET(sp, tfp, TAGF *, sizeof(TAGF));
 606         *tfp = *otfp;
 607
 608         /* XXX: Allocate as part of the TAGF structure!!! */
 609         if ((tfp->name = strdup(otfp->name)) == NULL)
 610                 return (1);
 611
 612         *tfpp = tfp;
 613         return (0);
 614 }
 615
 616 /*
 617  * tagq_copy --
 618  *      Copy a TAGQ structure and return it in new memory.
 619  */
 620 static int
 621 tagq_copy(SCR *sp, TAGQ *otqp, TAGQ **tqpp)
 622 {
 623         TAGQ *tqp;
 624         size_t len;
 625
 626         len = sizeof(TAGQ);
 627         if (otqp->tag != NULL)
 628                 len += otqp->tlen + 1;
 629         MALLOC_RET(sp, tqp, TAGQ *, len);
 630         memcpy(tqp, otqp, len);
 631
 632         CIRCLEQ_INIT(&tqp->tagq);
 633         tqp->current = NULL;
 634         if (otqp->tag != NULL)
 635                 tqp->tag = tqp->buf;
 636
 637         *tqpp = tqp;
 638         return (0);
 639 }
 640
 641 /*
 642  * tag_copy --
 643  *      Copy a TAG structure and return it in new memory.
 644  */
 645 static int
 646 tag_copy(SCR *sp, TAG *otp, TAG **tpp)
 647 {
 648         TAG *tp;
 649         size_t len;
 650
 651         len = sizeof(TAG);
 652         if (otp->fname != NULL)
 653                 len += otp->fnlen + 1;
 654         if (otp->search != NULL)
 655                 len += otp->slen + 1;
 656         if (otp->msg != NULL)
 657                 len += otp->mlen + 1;
 658         MALLOC_RET(sp, tp, TAG *, len);
 659         memcpy(tp, otp, len);
 660
 661         if (otp->fname != NULL)
 662                 tp->fname = (char *)tp->buf;
 663         if (otp->search != NULL)
 664                 tp->search = tp->buf + (otp->search - otp->buf);
 665         if (otp->msg != NULL)
 666                 tp->msg = tp->buf + (otp->msg - otp->buf);
 667
 668         *tpp = tp;
 669         return (0);
 670 }
 671
 672 /*
 673  * tagf_free --
 674  *      Free a TAGF structure.
 675  */
 676 static int
 677 tagf_free(SCR *sp, TAGF *tfp)
 678 {
 679         EX_PRIVATE *exp;
 680
 681         exp = EXP(sp);
 682         TAILQ_REMOVE(&exp->tagfq, tfp, q);
 683         free(tfp->name);
 684         free(tfp);
 685         return (0);
 686 }
 687
 688 /*
 689  * tagq_free --
 690  *      Free a TAGQ structure (and associated TAG structures).
 691  *
 692  * PUBLIC: int tagq_free __P((SCR *, TAGQ *));
 693  */
 694 int
 695 tagq_free(SCR *sp, TAGQ *tqp)
 696 {
 697         EX_PRIVATE *exp;
 698         TAG *tp;
 699
 700         exp = EXP(sp);
 701         while ((tp = tqp->tagq.cqh_first) != (void *)&tqp->tagq) {
 702                 CIRCLEQ_REMOVE(&tqp->tagq, tp, q);
 703                 free(tp);
 704         }
 705         /*
 706          * !!!
 707          * If allocated and then the user failed to switch files, the TAGQ
 708          * structure was never attached to any list.
 709          */
 710         if (tqp->q.cqe_next != NULL)
 711                 CIRCLEQ_REMOVE(&exp->tq, tqp, q);
 712         free(tqp);
 713         return (0);
 714 }
 715
 716 /*
 717  * PUBLIC: int tagq_push __P((SCR*, TAGQ*, int, int ));
 718  */
 719 int
 720 tagq_push(SCR *sp, TAGQ *tqp, int new_screen, int force)
 721 {
 722         EX_PRIVATE *exp;
 723         FREF *frp;
 724         TAG *rtp;
 725         TAGQ *rtqp;
 726         db_recno_t lno;
 727         size_t cno;
 728         int istmp;
 729         char *np;
 730         size_t nlen;
 731
 732         exp = EXP(sp);
 733
 734         /*
 735          * Allocate all necessary memory before swapping screens.  Initialize
 736          * flags so we know what to free.
 737          */
 738         rtp = NULL;
 739         rtqp = NULL;
 740         if (exp->tq.cqh_first == (void *)&exp->tq) {
 741                 /* Initialize the `local context' tag queue structure. */
 742                 CALLOC_GOTO(sp, rtqp, TAGQ *, 1, sizeof(TAGQ));
 743                 CIRCLEQ_INIT(&rtqp->tagq);
 744
 745                 /* Initialize and link in its tag structure. */
 746                 CALLOC_GOTO(sp, rtp, TAG *, 1, sizeof(TAG));
 747                 CIRCLEQ_INSERT_HEAD(&rtqp->tagq, rtp, q);
 748                 rtqp->current = rtp;
 749         }
 750
 751         /*
 752          * Stick the current context information in a convenient place, we're
 753          * about to lose it.  Note, if we're called on editor startup, there
 754          * will be no FREF structure.
 755          */
 756         frp = sp->frp;
 757         lno = sp->lno;
 758         cno = sp->cno;
 759         istmp = frp == NULL ||
 760             F_ISSET(frp, FR_TMPFILE) && !new_screen;
 761
 762         /* Try to switch to the tag. */
 763         if (new_screen) {
 764                 if (ex_tag_Nswitch(sp, tqp->tagq.cqh_first, force))
 765                         goto err;
 766
 767                 /* Everything else gets done in the new screen. */
 768                 sp = sp->nextdisp;
 769                 exp = EXP(sp);
 770         } else
 771                 if (ex_tag_nswitch(sp, tqp->tagq.cqh_first, force))
 772                         goto err;
 773
 774         /*
 775          * If this is the first tag, put a `current location' queue entry
 776          * in place, so we can pop all the way back to the current mark.
 777          * Note, it doesn't point to much of anything, it's a placeholder.
 778          */
 779         if (exp->tq.cqh_first == (void *)&exp->tq) {
 780                 CIRCLEQ_INSERT_HEAD(&exp->tq, rtqp, q);
 781         } else
 782                 rtqp = exp->tq.cqh_first;
 783
 784         /* Link the new TAGQ structure into place. */
 785         CIRCLEQ_INSERT_HEAD(&exp->tq, tqp, q);
 786
 787         (void)ctag_search(sp,
 788             tqp->current->search, tqp->current->slen, tqp->tag);
 789         if (tqp->current->msg) {
 790             INT2CHAR(sp, tqp->current->msg, tqp->current->mlen + 1,
 791                      np, nlen);
 792             msgq(sp, M_INFO, np);
 793         }
 794
 795         /*
 796          * Move the current context from the temporary save area into the
 797          * right structure.
 798          *
 799          * If we were in a temporary file, we don't have a context to which
 800          * we can return, so just make it be the same as what we're moving
 801          * to.  It will be a little odd that ^T doesn't change anything, but
 802          * I don't think it's a big deal.
 803          */
 804         if (istmp) {
 805                 rtqp->current->frp = sp->frp;
 806                 rtqp->current->lno = sp->lno;
 807                 rtqp->current->cno = sp->cno;
 808         } else {
 809                 rtqp->current->frp = frp;
 810                 rtqp->current->lno = lno;
 811                 rtqp->current->cno = cno;
 812         }
 813         return (0);
 814
 815 err:
 816 alloc_err:
 817         if (rtqp != NULL)
 818                 free(rtqp);
 819         if (rtp != NULL)
 820                 free(rtp);
 821         tagq_free(sp, tqp);
 822         return (1);
 823 }
 824
 825 /*
 826  * tag_msg
 827  *      A few common messages.
 828  *
 829  * PUBLIC: void tag_msg __P((SCR *, tagmsg_t, char *));
 830  */
 831 void
 832 tag_msg(SCR *sp, tagmsg_t msg, char *tag)
 833 {
 834         switch (msg) {
 835         case TAG_BADLNO:
 836                 msgq_str(sp, M_ERR, tag,
 837             "164|%s: the tag's line number is past the end of the file");
 838                 break;
 839         case TAG_EMPTY:
 840                 msgq(sp, M_INFO, "165|The tags stack is empty");
 841                 break;
 842         case TAG_SEARCH:
 843                 msgq_str(sp, M_ERR, tag, "166|%s: search pattern not found");
 844                 break;
 845         default:
 846                 abort();
 847         }
 848 }
 849
 850 /*
 851  * ex_tagf_alloc --
 852  *      Create a new list of ctag files.
 853  *
 854  * PUBLIC: int ex_tagf_alloc __P((SCR *, char *));
 855  */
 856 int
 857 ex_tagf_alloc(SCR *sp, char *str)
 858 {
 859         EX_PRIVATE *exp;
 860         TAGF *tfp;
 861         size_t len;
 862         char *p, *t;
 863
 864         /* Free current queue. */
 865         exp = EXP(sp);
 866         while ((tfp = exp->tagfq.tqh_first) != NULL)
 867                 tagf_free(sp, tfp);
 868
 869         /* Create new queue. */
 870         for (p = t = str;; ++p) {
 871                 if (*p == '\0' || isblank(*p)) {
 872                         if ((len = p - t) > 1) {
 873                                 MALLOC_RET(sp, tfp, TAGF *, sizeof(TAGF));
 874                                 MALLOC(sp, tfp->name, char *, len + 1);
 875                                 if (tfp->name == NULL) {
 876                                         free(tfp);
 877                                         return (1);
 878                                 }
 879                                 memcpy(tfp->name, t, len);
 880                                 tfp->name[len] = '\0';
 881                                 tfp->flags = 0;
 882                                 TAILQ_INSERT_TAIL(&exp->tagfq, tfp, q);
 883                         }
 884                         t = p + 1;
 885                 }
 886                 if (*p == '\0')
 887                          break;
 888         }
 889         return (0);
 890 }
 891                                                 /* Free previous queue. */
 892 /*
 893  * ex_tag_free --
 894  *      Free the ex tag information.
 895  *
 896  * PUBLIC: int ex_tag_free __P((SCR *));
 897  */
 898 int
 899 ex_tag_free(SCR *sp)
 900 {
 901         EX_PRIVATE *exp;
 902         TAGF *tfp;
 903         TAGQ *tqp;
 904
 905         /* Free up tag information. */
 906         exp = EXP(sp);
 907         while ((tqp = exp->tq.cqh_first) != (void *)&exp->tq)
 908                 tagq_free(sp, tqp);
 909         while ((tfp = exp->tagfq.tqh_first) != NULL)
 910                 tagf_free(sp, tfp);
 911         if (exp->tag_last != NULL)
 912                 free(exp->tag_last);
 913         return (0);
 914 }
 915
 916 /*
 917  * ctag_search --
 918  *      Search a file for a tag.
 919  */
 920 static int
 921 ctag_search(SCR *sp, CHAR_T *search, size_t slen, char *tag)
 922 {
 923         MARK m;
 924         char *p;
 925         char *np;
 926         size_t nlen;
 927
 928         /*
 929          * !!!
 930          * The historic tags file format (from a long, long time ago...)
 931          * used a line number, not a search string.  I got complaints, so
 932          * people are still using the format.  POSIX 1003.2 permits it.
 933          */
 934         if (ISDIGIT(search[0])) {
 935                 INT2CHAR(sp, search, slen+1, np, nlen);
 936                 m.lno = atoi(np);
 937                 if (!db_exist(sp, m.lno)) {
 938                         tag_msg(sp, TAG_BADLNO, tag);
 939                         return (1);
 940                 }
 941         } else {
 942                 /*
 943                  * Search for the tag; cheap fallback for C functions
 944                  * if the name is the same but the arguments have changed.
 945                  */
 946                 m.lno = 1;
 947                 m.cno = 0;
 948                 if (f_search(sp, &m, &m,
 949                     search, slen, NULL,
 950                     SEARCH_FIRST | SEARCH_TAG | SEARCH_PARSE)) {
 951                         INT2CHAR(sp, search, slen, np, nlen);
 952                         if ((p = strrchr(np, '(')) != NULL) {
 953                                 slen = p - np;
 954                                 if (f_search(sp, &m, &m, search, slen,
 955                                     NULL, SEARCH_FIRST | SEARCH_TAG))
 956                                         goto notfound;
 957                         } else {
 958 notfound:                       tag_msg(sp, TAG_SEARCH, tag);
 959                                 return (1);
 960                         }
 961                 }
 962                 /*
 963                  * !!!
 964                  * Historically, tags set the search direction if it wasn't
 965                  * already set.
 966                  */
 967                 if (sp->searchdir == NOTSET)
 968                         sp->searchdir = FORWARD;
 969         }
 970
 971         /*
 972          * !!!
 973          * Tags move to the first non-blank, NOT the search pattern start.
 974          */
 975         sp->lno = m.lno;
 976         sp->cno = 0;
 977         (void)nonblank(sp, sp->lno, &sp->cno);
 978         return (0);
 979 }
 980
 981 /*
 982  * ctag_slist --
 983  *      Search the list of tags files for a tag, and return tag queue.
 984  */
 985 static TAGQ *
 986 ctag_slist(SCR *sp, CHAR_T *tag)
 987 {
 988         EX_PRIVATE *exp;
 989         TAGF *tfp;
 990         TAGQ *tqp;
 991         size_t len;
 992         int echk;
 993         char *np;
 994         size_t nlen;
 995
 996         exp = EXP(sp);
 997
 998         /* Allocate and initialize the tag queue structure. */
 999         INT2CHAR(sp, tag, STRLEN(tag) + 1, np, nlen);
1000         len = nlen - 1;
1001         CALLOC_GOTO(sp, tqp, TAGQ *, 1, sizeof(TAGQ) + len + 1);
1002         CIRCLEQ_INIT(&tqp->tagq);
1003         tqp->tag = tqp->buf;
1004         memcpy(tqp->tag, np, (tqp->tlen = len) + 1);
1005
1006         /*
1007          * Find the tag, only display missing file messages once, and
1008          * then only if we didn't find the tag.
1009          */
1010         for (echk = 0,
1011             tfp = exp->tagfq.tqh_first; tfp != NULL; tfp = tfp->q.tqe_next)
1012                 if (ctag_sfile(sp, tfp, tqp, tqp->tag)) {
1013                         echk = 1;
1014                         F_SET(tfp, TAGF_ERR);
1015                 } else
1016                         F_CLR(tfp, TAGF_ERR | TAGF_ERR_WARN);
1017
1018         /* Check to see if we found anything. */
1019         if (tqp->tagq.cqh_first == (void *)&tqp->tagq) {
1020                 msgq_str(sp, M_ERR, tqp->tag, "162|%s: tag not found");
1021                 if (echk)
1022                         for (tfp = exp->tagfq.tqh_first;
1023                             tfp != NULL; tfp = tfp->q.tqe_next)
1024                                 if (F_ISSET(tfp, TAGF_ERR) &&
1025                                     !F_ISSET(tfp, TAGF_ERR_WARN)) {
1026                                         errno = tfp->errnum;
1027                                         msgq_str(sp, M_SYSERR, tfp->name, "%s");
1028                                         F_SET(tfp, TAGF_ERR_WARN);
1029                                 }
1030                 free(tqp);
1031                 return (NULL);
1032         }
1033
1034         tqp->current = tqp->tagq.cqh_first;
1035         return (tqp);
1036
1037 alloc_err:
1038         return (NULL);
1039 }
1040
1041 /*
1042  * ctag_sfile --
1043  *      Search a tags file for a tag, adding any found to the tag queue.
1044  */
1045 static int
1046 ctag_sfile(SCR *sp, TAGF *tfp, TAGQ *tqp, char *tname)
1047 {
1048         struct stat sb;
1049         TAG *tp;
1050         size_t dlen, nlen, slen;
1051         int fd, i, nf1, nf2;
1052         char *back, *cname, *dname, *front, *map, *name, *p, *search, *t;
1053         CHAR_T *wp;
1054         size_t wlen;
1055
1056         if ((fd = open(tfp->name, O_RDONLY, 0)) < 0) {
1057                 tfp->errnum = errno;
1058                 return (1);
1059         }
1060
1061         /*
1062          * XXX
1063          * Some old BSD systems require MAP_FILE as an argument when mapping
1064          * regular files.
1065          */
1066 #ifndef MAP_FILE
1067 #define MAP_FILE        0
1068 #endif
1069         /*
1070          * XXX
1071          * We'd like to test if the file is too big to mmap.  Since we don't
1072          * know what size or type off_t's or size_t's are, what the largest
1073          * unsigned integral type is, or what random insanity the local C
1074          * compiler will perpetrate, doing the comparison in a portable way
1075          * is flatly impossible.  Hope mmap fails if the file is too large.
1076          */
1077         if (fstat(fd, &sb) != 0 ||
1078             (map = mmap(NULL, (size_t)sb.st_size, PROT_READ | PROT_WRITE,
1079             MAP_FILE | MAP_PRIVATE, fd, (off_t)0)) == (caddr_t)-1) {
1080                 tfp->errnum = errno;
1081                 (void)close(fd);
1082                 return (1);
1083         }
1084
1085         front = map;
1086         back = front + sb.st_size;
1087         front = binary_search(tname, front, back);
1088         front = linear_search(tname, front, back);
1089         if (front == NULL)
1090                 goto done;
1091
1092         /*
1093          * Initialize and link in the tag structure(s).  The historic ctags
1094          * file format only permitted a single tag location per tag.  The
1095          * obvious extension to permit multiple tags locations per tag is to
1096          * output multiple records in the standard format.  Unfortunately,
1097          * this won't work correctly with historic ex/vi implementations,
1098          * because their binary search assumes that there's only one record
1099          * per tag, and so will use a random tag entry if there si more than
1100          * one.  This code handles either format.
1101          *
1102          * The tags file is in the following format:
1103          *
1104          *      <tag> <filename> <line number> | <pattern>
1105          *
1106          * Figure out how long everything is so we can allocate in one swell
1107          * foop, but discard anything that looks wrong.
1108          */
1109         for (;;) {
1110                 /* Nul-terminate the end of the line. */
1111                 for (p = front; p < back && *p != '\n'; ++p);
1112                 if (p == back || *p != '\n')
1113                         break;
1114                 *p = '\0';
1115
1116                 /* Update the pointers for the next time. */
1117                 t = p + 1;
1118                 p = front;
1119                 front = t;
1120
1121                 /* Break the line into tokens. */
1122                 for (i = 0; i < 2 && (t = strsep(&p, "\t ")) != NULL; ++i)
1123                         switch (i) {
1124                         case 0:                 /* Tag. */
1125                                 cname = t;
1126                                 break;
1127                         case 1:                 /* Filename. */
1128                                 name = t;
1129                                 nlen = strlen(name);
1130                                 break;
1131                         }
1132
1133                 /* Check for corruption. */
1134                 if (i != 2 || p == NULL || t == NULL)
1135                         goto corrupt;
1136
1137                 /* The rest of the string is the search pattern. */
1138                 search = p;
1139                 if ((slen = strlen(p)) == 0) {
1140 corrupt:                p = msg_print(sp, tname, &nf1);
1141                         t = msg_print(sp, tfp->name, &nf2);
1142                         msgq(sp, M_ERR, "163|%s: corrupted tag in %s", p, t);
1143                         if (nf1)
1144                                 FREE_SPACE(sp, p, 0);
1145                         if (nf2)
1146                                 FREE_SPACE(sp, t, 0);
1147                         continue;
1148                 }
1149
1150                 /* Check for passing the last entry. */
1151                 if (strcmp(tname, cname))
1152                         break;
1153
1154                 /* Resolve the file name. */
1155                 ctag_file(sp, tfp, name, &dname, &dlen);
1156
1157                 CALLOC_GOTO(sp, tp,
1158                     TAG *, 1, sizeof(TAG) + dlen + 2 + nlen + 1 +
1159                     (slen + 1) * sizeof(CHAR_T));
1160                 tp->fname = (char *)tp->buf;
1161                 if (dlen != 0) {
1162                         memcpy(tp->fname, dname, dlen);
1163                         tp->fname[dlen] = '/';
1164                         ++dlen;
1165                 }
1166                 memcpy(tp->fname + dlen, name, nlen + 1);
1167                 tp->fnlen = dlen + nlen;
1168                 tp->search = (CHAR_T*)(tp->fname + tp->fnlen + 1);
1169                 CHAR2INT(sp, search, slen + 1, wp, wlen);
1170                 MEMCPYW(tp->search, wp, (tp->slen = slen) + 1);
1171                 CIRCLEQ_INSERT_TAIL(&tqp->tagq, tp, q);
1172         }
1173
1174 alloc_err:
1175 done:   if (munmap(map, (size_t)sb.st_size))
1176                 msgq(sp, M_SYSERR, "munmap");
1177         if (close(fd))
1178                 msgq(sp, M_SYSERR, "close");
1179         return (0);
1180 }
1181
1182 /*
1183  * ctag_file --
1184  *      Search for the right path to this file.
1185  */
1186 static void
1187 ctag_file(SCR *sp, TAGF *tfp, char *name, char **dirp, size_t *dlenp)
1188 {
1189         struct stat sb;
1190         size_t len;
1191         char *p, buf[MAXPATHLEN];
1192
1193         /*
1194          * !!!
1195          * If the tag file path is a relative path, see if it exists.  If it
1196          * doesn't, look relative to the tags file path.  It's okay for a tag
1197          * file to not exist, and historically, vi simply displayed a "new"
1198          * file.  However, if the path exists relative to the tag file, it's
1199          * pretty clear what's happening, so we may as well get it right.
1200          */
1201         *dlenp = 0;
1202         if (name[0] != '/' &&
1203             stat(name, &sb) && (p = strrchr(tfp->name, '/')) != NULL) {
1204                 *p = '\0';
1205                 len = snprintf(buf, sizeof(buf), "%s/%s", tfp->name, name);
1206                 if (stat(buf, &sb) == 0) {
1207                         *dirp = tfp->name;
1208                         *dlenp = strlen(*dirp);
1209                 }
1210                 *p = '/';
1211         }
1212 }
1213
1214 /*
1215  * Binary search for "string" in memory between "front" and "back".
1216  *
1217  * This routine is expected to return a pointer to the start of a line at
1218  * *or before* the first word matching "string".  Relaxing the constraint
1219  * this way simplifies the algorithm.
1220  *
1221  * Invariants:
1222  *      front points to the beginning of a line at or before the first
1223  *      matching string.
1224  *
1225  *      back points to the beginning of a line at or after the first
1226  *      matching line.
1227  *
1228  * Base of the Invariants.
1229  *      front = NULL;
1230  *      back = EOF;
1231  *
1232  * Advancing the Invariants:
1233  *
1234  *      p = first newline after halfway point from front to back.
1235  *
1236  *      If the string at "p" is not greater than the string to match,
1237  *      p is the new front.  Otherwise it is the new back.
1238  *
1239  * Termination:
1240  *
1241  *      The definition of the routine allows it return at any point,
1242  *      since front is always at or before the line to print.
1243  *
1244  *      In fact, it returns when the chosen "p" equals "back".  This
1245  *      implies that there exists a string is least half as long as
1246  *      (back - front), which in turn implies that a linear search will
1247  *      be no more expensive than the cost of simply printing a string or two.
1248  *
1249  *      Trying to continue with binary search at this point would be
1250  *      more trouble than it's worth.
1251  */
1252 #define EQUAL           0
1253 #define GREATER         1
1254 #define LESS            (-1)
1255
1256 #define SKIP_PAST_NEWLINE(p, back)      while (p < back && *p++ != '\n');
1257
1258 static char *
1259 binary_search(register char *string, register char *front, register char *back)
1260 {
1261         register char *p;
1262
1263         p = front + (back - front) / 2;
1264         SKIP_PAST_NEWLINE(p, back);
1265
1266         while (p != back) {
1267                 if (compare(string, p, back) == GREATER)
1268                         front = p;
1269                 else
1270                         back = p;
1271                 p = front + (back - front) / 2;
1272                 SKIP_PAST_NEWLINE(p, back);
1273         }
1274         return (front);
1275 }
1276
1277 /*
1278  * Find the first line that starts with string, linearly searching from front
1279  * to back.
1280  *
1281  * Return NULL for no such line.
1282  *
1283  * This routine assumes:
1284  *
1285  *      o front points at the first character in a line.
1286  *      o front is before or at the first line to be printed.
1287  */
1288 static char *
1289 linear_search(char *string, char *front, char *back)
1290 {
1291         while (front < back) {
1292                 switch (compare(string, front, back)) {
1293                 case EQUAL:             /* Found it. */
1294                         return (front);
1295                 case LESS:              /* No such string. */
1296                         return (NULL);
1297                 case GREATER:           /* Keep going. */
1298                         break;
1299                 }
1300                 SKIP_PAST_NEWLINE(front, back);
1301         }
1302         return (NULL);
1303 }
1304
1305 /*
1306  * Return LESS, GREATER, or EQUAL depending on how the string1 compares
1307  * with string2 (s1 ??? s2).
1308  *
1309  *      o Matches up to len(s1) are EQUAL.
1310  *      o Matches up to len(s2) are GREATER.
1311  *
1312  * The string "s1" is null terminated.  The string s2 is '\t', space, (or
1313  * "back") terminated.
1314  *
1315  * !!!
1316  * Reasonably modern ctags programs use tabs as separators, not spaces.
1317  * However, historic programs did use spaces, and, I got complaints.
1318  */
1319 static int
1320 compare(register char *s1, register char *s2, register char *back)
1321 {
1322         for (; *s1 && s2 < back && (*s2 != '\t' && *s2 != ' '); ++s1, ++s2)
1323                 if (*s1 != *s2)
1324                         return (*s1 < *s2 ? LESS : GREATER);
1325         return (*s1 ? GREATER : s2 < back &&
1326             (*s2 != '\t' && *s2 != ' ') ? LESS : EQUAL);
1327 }