text: /*
   * VIM - Vi IMproved	by Bram Moolenaar
   *
   * Do ":help uganda"  in Vim to read copying and usage conditions.
   * Do ":help credits" in Vim to see a list of people who contributed.
   * See README.txt for an overview of the Vim source code.
   */
  
  /*
   * Code to handle tags and the tag stack
   */
  
  #include <assert.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <stdbool.h>
  #include <string.h>
  
  #include "nvim/vim.h"
  #include "nvim/ascii.h"
  #include "nvim/tag.h"
  #include "nvim/buffer.h"
  #include "nvim/charset.h"
  #include "nvim/cursor.h"
  #include "nvim/edit.h"
  #include "nvim/eval.h"
  #include "nvim/ex_cmds.h"
  #include "nvim/ex_cmds2.h"
  #include "nvim/ex_docmd.h"
  #include "nvim/ex_getln.h"
  #include "nvim/fileio.h"
  #include "nvim/fold.h"
  #include "nvim/if_cscope.h"
  #include "nvim/mark.h"
  #include "nvim/mbyte.h"
  #include "nvim/message.h"
  #include "nvim/misc1.h"
  #include "nvim/misc2.h"
  #include "nvim/file_search.h"
  #include "nvim/garray.h"
  #include "nvim/memory.h"
  #include "nvim/move.h"
  #include "nvim/option.h"
  #include "nvim/os_unix.h"
  #include "nvim/path.h"
  #include "nvim/quickfix.h"
  #include "nvim/regexp.h"
  #include "nvim/screen.h"
  #include "nvim/search.h"
  #include "nvim/strings.h"
  #include "nvim/ui.h"
  #include "nvim/window.h"
  #include "nvim/os/os.h"
  #include "nvim/os/time.h"
  #include "nvim/os/input.h"
  
  /*
   * Structure to hold pointers to various items in a tag line.
   */
  typedef struct tag_pointers {
    /* filled in by parse_tag_line(): */
    char_u      *tagname;         /* start of tag name (skip "file:") */
    char_u      *tagname_end;     /* char after tag name */
    char_u      *fname;           /* first char of file name */
    char_u      *fname_end;       /* char after file name */
    char_u      *command;         /* first char of command */
    /* filled in by parse_match(): */
    char_u      *command_end;     /* first char after command */
    char_u      *tag_fname;       /* file name of the tags file */
    char_u      *tagkind;         /* "kind:" value */
    char_u      *tagkind_end;     /* end of tagkind */
  } tagptrs_T;
  
  /*
   * Structure to hold info about the tag pattern being used.
   */
  typedef struct {
    char_u      *pat;             /* the pattern */
    int len;                      /* length of pat[] */
    char_u      *head;            /* start of pattern head */
    int headlen;                  /* length of head[] */
    regmatch_T regmatch;          /* regexp program, may be NULL */
  } pat_T;
  
  /*
   * The matching tags are first stored in ga_match[].  In which one depends on
   * the priority of the match.
   * At the end, the matches from ga_match[] are concatenated, to make a list
   * sorted on priority.
   */
  #define MT_ST_CUR       0               /* static match in current file */
  #define MT_GL_CUR       1               /* global match in current file */
  #define MT_GL_OTH       2               /* global match in other file */
  #define MT_ST_OTH       3               /* static match in other file */
  #define MT_IC_ST_CUR    4               /* icase static match in current file */
  #define MT_IC_GL_CUR    5               /* icase global match in current file */
  #define MT_IC_GL_OTH    6               /* icase global match in other file */
  #define MT_IC_ST_OTH    7               /* icase static match in other file */
  #define MT_IC_OFF       4               /* add for icase match */
  #define MT_RE_OFF       8               /* add for regexp match */
  #define MT_MASK         7               /* mask for printing priority */
  #define MT_COUNT        16
  
  static char     *mt_names[MT_COUNT/2] =
  {"FSC", "F C", "F  ", "FS ", " SC", "  C", "   ", " S "};
  
  #define NOTAGFILE       99              /* return value for jumpto_tag */
  static char_u   *nofile_fname = NULL;   /* fname for NOTAGFILE error */
  
  
  #ifdef INCLUDE_GENERATED_DECLARATIONS
  # include "tag.c.generated.h"
  #endif
  
  static char_u *bottommsg = (char_u *)N_("E555: at bottom of tag stack");
  static char_u *topmsg = (char_u *)N_("E556: at top of tag stack");
  
  static char_u   *tagmatchname = NULL;   /* name of last used tag */
  
  /*
   * We use ftello() here, if available.  It returns off_t instead of long,
   * which helps if long is 32 bit and off_t is 64 bit.
   * We assume that when fseeko() is available then ftello() is too.
   */
  #ifdef HAVE_FSEEKO
  # define ftell ftello
  #endif
  
  /*
   * Tag for preview window is remembered separately, to avoid messing up the
   * normal tagstack.
   */
  static taggy_T ptag_entry = {NULL, {INIT_POS_T(0, 0, 0), 0}, 0, 0};
  
  /*
   * Jump to tag; handling of tag commands and tag stack
   *
   * *tag != NUL: ":tag {tag}", jump to new tag, add to tag stack
   *
   * type == DT_TAG:	":tag [tag]", jump to newer position or same tag again
   * type == DT_HELP:	like DT_TAG, but don't use regexp.
   * type == DT_POP:	":pop" or CTRL-T, jump to old position
   * type == DT_NEXT:	jump to next match of same tag
   * type == DT_PREV:	jump to previous match of same tag
   * type == DT_FIRST:	jump to first match of same tag
   * type == DT_LAST:	jump to last match of same tag
   * type == DT_SELECT:	":tselect [tag]", select tag from a list of all matches
   * type == DT_JUMP:	":tjump [tag]", jump to tag or select tag from a list
   * type == DT_CSCOPE:	use cscope to find the tag
   * type == DT_LTAG:	use location list for displaying tag matches
   * type == DT_FREE:	free cached matches
   *
   * for cscope, returns TRUE if we jumped to tag or aborted, FALSE otherwise
   */
  int 
  do_tag (
      char_u *tag,               /* tag (pattern) to jump to */
      int type,
      int count,
      int forceit,                    /* :ta with ! */
      int verbose                    /* print "tag not found" message */
  )
  {
    taggy_T     *tagstack = curwin->w_tagstack;
    int tagstackidx = curwin->w_tagstackidx;
    int tagstacklen = curwin->w_tagstacklen;
    int cur_match = 0;
    int cur_fnum = curbuf->b_fnum;
    int oldtagstackidx = tagstackidx;
    int prevtagstackidx = tagstackidx;
    int prev_num_matches;
    int new_tag = FALSE;
    int other_name;
    int i, j, k;
    int idx;
    int ic;
    char_u      *p;
    char_u      *name;
    int no_regexp = FALSE;
    int error_cur_match = 0;
    char_u      *command_end;
    int save_pos = FALSE;
    fmark_T saved_fmark;
    int taglen;
    int jumped_to_tag = FALSE;
    tagptrs_T tagp, tagp2;
    int new_num_matches;
    char_u      **new_matches;
    int attr;
    int use_tagstack;
    int skip_msg = FALSE;
    char_u      *buf_ffname = curbuf->b_ffname;       /* name to use for
                                                         priority computation */
  
    /* remember the matches for the last used tag */
    static int num_matches = 0;
    static int max_num_matches = 0;             /* limit used for match search */
    static char_u       **matches = NULL;
    static int flags;
  
  #ifdef EXITFREE
    if (type == DT_FREE) {
      /* remove the list of matches */
      FreeWild(num_matches, matches);
      cs_free_tags();
      num_matches = 0;
      return FALSE;
    }
  #endif
  
    if (type == DT_HELP) {
      type = DT_TAG;
      no_regexp = TRUE;
    }
  
    prev_num_matches = num_matches;
    free_string_option(nofile_fname);
    nofile_fname = NULL;
  
    clearpos(&saved_fmark.mark);          /* shutup gcc 4.0 */
    saved_fmark.fnum = 0;
  
    /*
     * Don't add a tag to the tagstack if 'tagstack' has been reset.
     */
    if ((!p_tgst && *tag != NUL)) {
      use_tagstack = FALSE;
      new_tag = TRUE;
    } else {
      if (g_do_tagpreview != 0)
        use_tagstack = FALSE;
      else
        use_tagstack = TRUE;
  
      /* new pattern, add to the tag stack */
      if (*tag != NUL
          && (type == DT_TAG || type == DT_SELECT || type == DT_JUMP
              || type == DT_LTAG
              || type == DT_CSCOPE
              )) {
        if (g_do_tagpreview != 0) {
          if (ptag_entry.tagname != NULL
              && STRCMP(ptag_entry.tagname, tag) == 0) {
            /* Jumping to same tag: keep the current match, so that
             * the CursorHold autocommand example works. */
            cur_match = ptag_entry.cur_match;
            cur_fnum = ptag_entry.cur_fnum;
          } else {
            free(ptag_entry.tagname);
            ptag_entry.tagname = vim_strsave(tag);
          }
        } else {
          /*
           * If the last used entry is not at the top, delete all tag
           * stack entries above it.
           */
          while (tagstackidx < tagstacklen)
            free(tagstack[--tagstacklen].tagname);
  
          /* if the tagstack is full: remove oldest entry */
          if (++tagstacklen > TAGSTACKSIZE) {
            tagstacklen = TAGSTACKSIZE;
            free(tagstack[0].tagname);
            for (i = 1; i < tagstacklen; ++i)
              tagstack[i - 1] = tagstack[i];
            --tagstackidx;
          }
  
          // put the tag name in the tag stack
          tagstack[tagstackidx].tagname = vim_strsave(tag);
  
          curwin->w_tagstacklen = tagstacklen;
  
          save_pos = TRUE;                /* save the cursor position below */
        }
  
        new_tag = TRUE;
      } else {
        if (
          g_do_tagpreview != 0 ? ptag_entry.tagname == NULL :
          tagstacklen == 0) {
          /* empty stack */
          EMSG(_(e_tagstack));
          goto end_do_tag;
        }
  
        if (type == DT_POP) {             /* go to older position */
          int old_KeyTyped = KeyTyped;
          if ((tagstackidx -= count) < 0) {
            EMSG(_(bottommsg));
            if (tagstackidx + count == 0) {
              /* We did [num]^T from the bottom of the stack */
              tagstackidx = 0;
              goto end_do_tag;
            }
            /* We weren't at the bottom of the stack, so jump all the
             * way to the bottom now.
             */
            tagstackidx = 0;
          } else if (tagstackidx >= tagstacklen)   {      /* count == 0? */
            EMSG(_(topmsg));
            goto end_do_tag;
          }
  
          /* Make a copy of the fmark, autocommands may invalidate the
           * tagstack before it's used. */
          saved_fmark = tagstack[tagstackidx].fmark;
          if (saved_fmark.fnum != curbuf->b_fnum) {
            /*
             * Jump to other file. If this fails (e.g. because the
             * file was changed) keep original position in tag stack.
             */
            if (buflist_getfile(saved_fmark.fnum, saved_fmark.mark.lnum,
                    GETF_SETMARK, forceit) == FAIL) {
              tagstackidx = oldtagstackidx;              /* back to old posn */
              goto end_do_tag;
            }
            /* A BufReadPost autocommand may jump to the '" mark, but
             * we don't what that here. */
            curwin->w_cursor.lnum = saved_fmark.mark.lnum;
          } else {
            setpcmark();
            curwin->w_cursor.lnum = saved_fmark.mark.lnum;
          }
          curwin->w_cursor.col = saved_fmark.mark.col;
          curwin->w_set_curswant = TRUE;
          check_cursor();
          if ((fdo_flags & FDO_TAG) && old_KeyTyped)
            foldOpenCursor();
  
          /* remove the old list of matches */
          FreeWild(num_matches, matches);
          cs_free_tags();
          num_matches = 0;
          tag_freematch();
          goto end_do_tag;
        }
  
        if (type == DT_TAG
            || type == DT_LTAG
            ) {
          if (g_do_tagpreview != 0) {
            cur_match = ptag_entry.cur_match;
            cur_fnum = ptag_entry.cur_fnum;
          } else {
            /* ":tag" (no argument): go to newer pattern */
            save_pos = TRUE;              /* save the cursor position below */
            if ((tagstackidx += count - 1) >= tagstacklen) {
              /*
               * Beyond the last one, just give an error message and
               * go to the last one.  Don't store the cursor
               * position.
               */
              tagstackidx = tagstacklen - 1;
              EMSG(_(topmsg));
              save_pos = FALSE;
            } else if (tagstackidx < 0)   {       /* must have been count == 0 */
              EMSG(_(bottommsg));
              tagstackidx = 0;
              goto end_do_tag;
            }
            cur_match = tagstack[tagstackidx].cur_match;
            cur_fnum = tagstack[tagstackidx].cur_fnum;
          }
          new_tag = TRUE;
        } else {                                /* go to other matching tag */
          /* Save index for when selection is cancelled. */
          prevtagstackidx = tagstackidx;
  
          if (g_do_tagpreview != 0) {
            cur_match = ptag_entry.cur_match;
            cur_fnum = ptag_entry.cur_fnum;
          } else {
            if (--tagstackidx < 0)
              tagstackidx = 0;
            cur_match = tagstack[tagstackidx].cur_match;
            cur_fnum = tagstack[tagstackidx].cur_fnum;
          }
          switch (type) {
          case DT_FIRST: cur_match = count - 1; break;
          case DT_SELECT:
          case DT_JUMP:
          case DT_CSCOPE:
          case DT_LAST:  cur_match = MAXCOL - 1; break;
          case DT_NEXT:  cur_match += count; break;
          case DT_PREV:  cur_match -= count; break;
          }
          if (cur_match >= MAXCOL)
            cur_match = MAXCOL - 1;
          else if (cur_match < 0) {
            EMSG(_("E425: Cannot go before first matching tag"));
            skip_msg = TRUE;
            cur_match = 0;
            cur_fnum = curbuf->b_fnum;
          }
        }
      }
  
      if (g_do_tagpreview != 0) {
        if (type != DT_SELECT && type != DT_JUMP) {
          ptag_entry.cur_match = cur_match;
          ptag_entry.cur_fnum = cur_fnum;
        }
      } else {
        /*
         * For ":tag [arg]" or ":tselect" remember position before the jump.
         */
        saved_fmark = tagstack[tagstackidx].fmark;
        if (save_pos) {
          tagstack[tagstackidx].fmark.mark = curwin->w_cursor;
          tagstack[tagstackidx].fmark.fnum = curbuf->b_fnum;
        }
  
        /* Curwin will change in the call to jumpto_tag() if ":stag" was
         * used or an autocommand jumps to another window; store value of
         * tagstackidx now. */
        curwin->w_tagstackidx = tagstackidx;
        if (type != DT_SELECT && type != DT_JUMP) {
          curwin->w_tagstack[tagstackidx].cur_match = cur_match;
          curwin->w_tagstack[tagstackidx].cur_fnum = cur_fnum;
        }
      }
    }
  
    /* When not using the current buffer get the name of buffer "cur_fnum".
     * Makes sure that the tag order doesn't change when using a remembered
     * position for "cur_match". */
    if (cur_fnum != curbuf->b_fnum) {
      buf_T *buf = buflist_findnr(cur_fnum);
  
      if (buf != NULL)
        buf_ffname = buf->b_ffname;
    }
  
    /*
     * Repeat searching for tags, when a file has not been found.
     */
    for (;; ) {
      /*
       * When desired match not found yet, try to find it (and others).
       */
      if (use_tagstack)
        name = tagstack[tagstackidx].tagname;
      else if (g_do_tagpreview != 0)
        name = ptag_entry.tagname;
      else
        name = tag;
      other_name = (tagmatchname == NULL || STRCMP(tagmatchname, name) != 0);
      if (new_tag
          || (cur_match >= num_matches && max_num_matches != MAXCOL)
          || other_name) {
        if (other_name) {
          free(tagmatchname);
          tagmatchname = vim_strsave(name);
        }
  
        /*
         * If a count is supplied to the ":tag <name>" command, then
         * jump to count'th matching tag.
         */
        if (type == DT_TAG && *tag != NUL && count > 0)
          cur_match = count - 1;
  
        if (type == DT_SELECT || type == DT_JUMP
            || type == DT_LTAG
            )
          cur_match = MAXCOL - 1;
        max_num_matches = cur_match + 1;
  
        /* when the argument starts with '/', use it as a regexp */
        if (!no_regexp && *name == '/') {
          flags = TAG_REGEXP;
          ++name;
        } else
          flags = TAG_NOIC;
  
        if (type == DT_CSCOPE)
          flags = TAG_CSCOPE;
        if (verbose)
          flags |= TAG_VERBOSE;
        if (find_tags(name, &new_num_matches, &new_matches, flags,
                max_num_matches, buf_ffname) == OK
            && new_num_matches < max_num_matches)
          max_num_matches = MAXCOL;         /* If less than max_num_matches
                                               found: all matches found. */
  
        /* If there already were some matches for the same name, move them
         * to the start.  Avoids that the order changes when using
         * ":tnext" and jumping to another file. */
        if (!new_tag && !other_name) {
          /* Find the position of each old match in the new list.  Need
           * to use parse_match() to find the tag line. */
          idx = 0;
          for (j = 0; j < num_matches; ++j) {
            parse_match(matches[j], &tagp);
            for (i = idx; i < new_num_matches; ++i) {
              parse_match(new_matches[i], &tagp2);
              if (STRCMP(tagp.tagname, tagp2.tagname) == 0) {
                p = new_matches[i];
                for (k = i; k > idx; --k)
                  new_matches[k] = new_matches[k - 1];
                new_matches[idx++] = p;
                break;
              }
            }
          }
        }
        FreeWild(num_matches, matches);
        num_matches = new_num_matches;
        matches = new_matches;
      }
  
      if (num_matches <= 0) {
        if (verbose)
          EMSG2(_("E426: tag not found: %s"), name);
        g_do_tagpreview = 0;
      } else {
        int ask_for_selection = FALSE;
  
        if (type == DT_CSCOPE && num_matches > 1) {
          cs_print_tags();
          ask_for_selection = TRUE;
        } else if (type == DT_SELECT ||
                   (type == DT_JUMP && num_matches > 1))        {
          /*
           * List all the matching tags.
           * Assume that the first match indicates how long the tags can
           * be, and align the file names to that.
           */
          parse_match(matches[0], &tagp);
          taglen = (int)(tagp.tagname_end - tagp.tagname + 2);
          if (taglen < 18)
            taglen = 18;
          if (taglen > Columns - 25)
            taglen = MAXCOL;
          if (msg_col == 0)
            msg_didout = FALSE;           /* overwrite previous message */
          msg_start();
          MSG_PUTS_ATTR(_("  # pri kind tag"), hl_attr(HLF_T));
          msg_clr_eos();
          taglen_advance(taglen);
          MSG_PUTS_ATTR(_("file\n"), hl_attr(HLF_T));
  
          for (i = 0; i < num_matches && !got_int; ++i) {
            parse_match(matches[i], &tagp);
            if (!new_tag && (
                  (g_do_tagpreview != 0
                   && i == ptag_entry.cur_match) ||
                  (use_tagstack
                   && i == tagstack[tagstackidx].cur_match)))
              *IObuff = '>';
            else
              *IObuff = ' ';
            vim_snprintf((char *)IObuff + 1, IOSIZE - 1,
                "%2d %s ", i + 1,
                mt_names[matches[i][0] & MT_MASK]);
            msg_puts(IObuff);
            if (tagp.tagkind != NULL)
              msg_outtrans_len(tagp.tagkind,
                  (int)(tagp.tagkind_end - tagp.tagkind));
            msg_advance(13);
            msg_outtrans_len_attr(tagp.tagname,
                (int)(tagp.tagname_end - tagp.tagname),
                hl_attr(HLF_T));
            msg_putchar(' ');
            taglen_advance(taglen);
  
            /* Find out the actual file name. If it is long, truncate
             * it and put "..." in the middle */
            p = tag_full_fname(&tagp);
            msg_puts_long_attr(p, hl_attr(HLF_D));
            free(p);
  
            if (msg_col > 0)
              msg_putchar('\n');
            if (got_int)
              break;
            msg_advance(15);
  
            /* print any extra fields */
            command_end = tagp.command_end;
            if (command_end != NULL) {
              p = command_end + 3;
              while (*p && *p != '\r' && *p != '\n') {
                while (*p == TAB)
                  ++p;
  
                /* skip "file:" without a value (static tag) */
                if (STRNCMP(p, "file:", 5) == 0
                    && vim_isspace(p[5])) {
                  p += 5;
                  continue;
                }
                /* skip "kind:<kind>" and "<kind>" */
                if (p == tagp.tagkind
                    || (p + 5 == tagp.tagkind
                        && STRNCMP(p, "kind:", 5) == 0)) {
                  p = tagp.tagkind_end;
                  continue;
                }
                /* print all other extra fields */
                attr = hl_attr(HLF_CM);
                while (*p && *p != '\r' && *p != '\n') {
                  if (msg_col + ptr2cells(p) >= Columns) {
                    msg_putchar('\n');
                    if (got_int)
                      break;
                    msg_advance(15);
                  }
                  p = msg_outtrans_one(p, attr);
                  if (*p == TAB) {
                    msg_puts_attr((char_u *)" ", attr);
                    break;
                  }
                  if (*p == ':')
                    attr = 0;
                }
              }
              if (msg_col > 15) {
                msg_putchar('\n');
                if (got_int)
                  break;
                msg_advance(15);
              }
            } else {
              for (p = tagp.command;
                   *p && *p != '\r' && *p != '\n'; ++p)
                ;
              command_end = p;
            }
  
            /*
             * Put the info (in several lines) at column 15.
             * Don't display "/^" and "?^".
             */
            p = tagp.command;
            if (*p == '/' || *p == '?') {
              ++p;
              if (*p == '^')
                ++p;
            }
            /* Remove leading whitespace from pattern */
            while (p != command_end && vim_isspace(*p))
              ++p;
  
            while (p != command_end) {
              if (msg_col + (*p == TAB ? 1 : ptr2cells(p)) > Columns)
                msg_putchar('\n');
              if (got_int)
                break;
              msg_advance(15);
  
              // Skip backslash used for escaping a command char or a backslash.
              if (*p == '\\' && (*(p + 1) == *tagp.command
                                 || *(p + 1) == '\\')) {
                ++p;
              }
  
              if (*p == TAB) {
                msg_putchar(' ');
                ++p;
              } else
                p = msg_outtrans_one(p, 0);
  
              /* don't display the "$/;\"" and "$?;\"" */
              if (p == command_end - 2 && *p == '$'
                  && *(p + 1) == *tagp.command)
                break;
              /* don't display matching '/' or '?' */
              if (p == command_end - 1 && *p == *tagp.command
                  && (*p == '/' || *p == '?'))
                break;
            }
            if (msg_col)
              msg_putchar('\n');
            os_breakcheck();
          }
          if (got_int)
            got_int = FALSE;              /* only stop the listing */
          ask_for_selection = TRUE;
        } else if (type == DT_LTAG)   {
          list_T  *list;
          char_u tag_name[128 + 1];
          char_u  *fname;
          char_u  *cmd;
  
          /*
           * Add the matching tags to the location list for the current
           * window.
           */
  
          fname = xmalloc(MAXPATHL + 1);
          cmd = xmalloc(CMDBUFFSIZE + 1);
          list = list_alloc();
  
          for (i = 0; i < num_matches; ++i) {
            int len, cmd_len;
            long lnum;
            dict_T  *dict;
  
            parse_match(matches[i], &tagp);
  
            /* Save the tag name */
            len = (int)(tagp.tagname_end - tagp.tagname);
            if (len > 128)
              len = 128;
            STRLCPY(tag_name, tagp.tagname, len + 1);
  
            /* Save the tag file name */
            p = tag_full_fname(&tagp);
            STRLCPY(fname, p, MAXPATHL + 1);
            free(p);
  
            /*
             * Get the line number or the search pattern used to locate
             * the tag.
             */
            lnum = 0;
            if (isdigit(*tagp.command))
              /* Line number is used to locate the tag */
              lnum = atol((char *)tagp.command);
            else {
              char_u *cmd_start, *cmd_end;
  
              /* Search pattern is used to locate the tag */
  
              /* Locate the end of the command */
              cmd_start = tagp.command;
              cmd_end = tagp.command_end;
              if (cmd_end == NULL) {
                for (p = tagp.command;
                     *p && *p != '\r' && *p != '\n'; ++p)
                  ;
                cmd_end = p;
              }
  
              /*
               * Now, cmd_end points to the character after the
               * command. Adjust it to point to the last
               * character of the command.
               */
              cmd_end--;
  
              /*
               * Skip the '/' and '?' characters at the
               * beginning and end of the search pattern.
               */
              if (*cmd_start == '/' || *cmd_start == '?')
                cmd_start++;
  
              if (*cmd_end == '/' || *cmd_end == '?')
                cmd_end--;
  
              len = 0;
              cmd[0] = NUL;
  
              /*
               * If "^" is present in the tag search pattern, then
               * copy it first.
               */
              if (*cmd_start == '^') {
                STRCPY(cmd, "^");
                cmd_start++;
                len++;
              }
  
              /*
               * Precede the tag pattern with \V to make it very
               * nomagic.
               */
              STRCAT(cmd, "\\V");
              len += 2;
  
              cmd_len = (int)(cmd_end - cmd_start + 1);
              if (cmd_len > (CMDBUFFSIZE - 5))
                cmd_len = CMDBUFFSIZE - 5;
              STRNCAT(cmd, cmd_start, cmd_len);
              len += cmd_len;
  
              if (cmd[len - 1] == '$') {
                /*
                 * Replace '$' at the end of the search pattern
                 * with '\$'
                 */
                cmd[len - 1] = '\\';
                cmd[len] = '$';
                len++;
              }
  
              cmd[len] = NUL;
            }
  
            dict = dict_alloc();
            list_append_dict(list, dict);
  
            dict_add_nr_str(dict, "text", 0L, tag_name);
            dict_add_nr_str(dict, "filename", 0L, fname);
            dict_add_nr_str(dict, "lnum", lnum, NULL);
            if (lnum == 0)
              dict_add_nr_str(dict, "pattern", 0L, cmd);
          }
  
          vim_snprintf((char *)IObuff, IOSIZE, "ltag %s", tag);
          set_errorlist(curwin, list, ' ', IObuff);
  
          list_free(list, TRUE);
          free(fname);
          free(cmd);
  
          cur_match = 0;                  /* Jump to the first tag */
        }
  
        if (ask_for_selection == TRUE) {
          /*
           * Ask to select a tag from the list.
           */
          i = prompt_for_number(NULL);
          if (i <= 0 || i > num_matches || got_int) {
            /* no valid choice: don't change anything */
            if (use_tagstack) {
              tagstack[tagstackidx].fmark = saved_fmark;
              tagstackidx = prevtagstackidx;
            }
            cs_free_tags();
            jumped_to_tag = TRUE;
            break;
          }
          cur_match = i - 1;
        }
  
        if (cur_match >= num_matches) {
          /* Avoid giving this error when a file wasn't found and we're
           * looking for a match in another file, which wasn't found.
           * There will be an EMSG("file doesn't exist") below then. */
          if ((type == DT_NEXT || type == DT_FIRST)
              && nofile_fname == NULL) {
            if (num_matches == 1)
              EMSG(_("E427: There is only one matching tag"));
            else
              EMSG(_("E428: Cannot go beyond last matching tag"));
            skip_msg = TRUE;
          }
          cur_match = num_matches - 1;
        }
        if (use_tagstack) {
          tagstack[tagstackidx].cur_match = cur_match;
          tagstack[tagstackidx].cur_fnum = cur_fnum;
          ++tagstackidx;
        } else if (g_do_tagpreview != 0)   {
          ptag_entry.cur_match = cur_match;
          ptag_entry.cur_fnum = cur_fnum;
        }
  
        /*
         * Only when going to try the next match, report that the previous
         * file didn't exist.  Otherwise an EMSG() is given below.
         */
        if (nofile_fname != NULL && error_cur_match != cur_match)
          smsg((char_u *)_("File \"%s\" does not exist"), nofile_fname);
  
  
        ic = (matches[cur_match][0] & MT_IC_OFF);
        if (type != DT_SELECT && type != DT_JUMP
            && type != DT_CSCOPE
            && (num_matches > 1 || ic)
            && !skip_msg) {
          /* Give an indication of the number of matching tags */
          sprintf((char *)IObuff, _("tag %d of %d%s"),
              cur_match + 1,
              num_matches,
              max_num_matches != MAXCOL ? _(" or more") : "");
          if (ic)
            STRCAT(IObuff, _("  Using tag with different case!"));
          if ((num_matches > prev_num_matches || new_tag)
              && num_matches > 1) {
            if (ic)
              msg_attr(IObuff, hl_attr(HLF_W));
            else
              msg(IObuff);
            msg_scroll = TRUE;            /* don't overwrite this message */
          } else
            give_warning(IObuff, ic);
          if (ic && !msg_scrolled && msg_silent == 0) {
            ui_flush();
            os_delay(1000L, true);
          }
        }
  
        /* Let the SwapExists event know what tag we are jumping to. */
        vim_snprintf((char *)IObuff, IOSIZE, ":ta %s\r", name);
        set_vim_var_string(VV_SWAPCOMMAND, IObuff, -1);
  
        /*
         * Jump to the desired match.
         */
        i = jumpto_tag(matches[cur_match], forceit, type != DT_CSCOPE);
  
        set_vim_var_string(VV_SWAPCOMMAND, NULL, -1);
  
        if (i == NOTAGFILE) {
          /* File not found: try again with another matching tag */
          if ((type == DT_PREV && cur_match > 0)
              || ((type == DT_TAG || type == DT_NEXT
                   || type == DT_FIRST)
                  && (max_num_matches != MAXCOL
                      || cur_match < num_matches - 1))) {
            error_cur_match = cur_match;
            if (use_tagstack)
              --tagstackidx;
            if (type == DT_PREV)
              --cur_match;
            else {
              type = DT_NEXT;
              ++cur_match;
            }
            continue;
          }
          EMSG2(_("E429: File \"%s\" does not exist"), nofile_fname);
        } else {
          /* We may have jumped to another window, check that
           * tagstackidx is still valid. */
          if (use_tagstack && tagstackidx > curwin->w_tagstacklen)
            tagstackidx = curwin->w_tagstackidx;
          jumped_to_tag = TRUE;
        }
      }
      break;
    }
  
  end_do_tag:
    /* Only store the new index when using the tagstack and it's valid. */
    if (use_tagstack && tagstackidx <= curwin->w_tagstacklen)
      curwin->w_tagstackidx = tagstackidx;
    postponed_split = 0;          /* don't split next time */
  
    return jumped_to_tag;
  }
  
  /*
   * Free cached tags.
   */
  void tag_freematch(void)
  {
    free(tagmatchname);
    tagmatchname = NULL;
  }
  
  static void taglen_advance(int l)
  {
    if (l == MAXCOL) {
      msg_putchar('\n');
      msg_advance(24);
    } else
      msg_advance(13 + l);
  }
  
  /*
   * Print the tag stack
   */
  void do_tags(exarg_T *eap)
  {
    int i;
    char_u      *name;
    taggy_T     *tagstack = curwin->w_tagstack;
    int tagstackidx = curwin->w_tagstackidx;
    int tagstacklen = curwin->w_tagstacklen;
  
    /* Highlight title */
    MSG_PUTS_TITLE(_("\n  # TO tag         FROM line  in file/text"));
    for (i = 0; i < tagstacklen; ++i) {
      if (tagstack[i].tagname != NULL) {
        name = fm_getname(&(tagstack[i].fmark), 30);
        if (name == NULL)             /* file name not available */
          continue;
  
        msg_putchar('\n');
        sprintf((char *)IObuff, "%c%2d %2d %-15s %5ld  ",
            i == tagstackidx ? '>' : ' ',
            i + 1,
            tagstack[i].cur_match + 1,
            tagstack[i].tagname,
            tagstack[i].fmark.mark.lnum);
        msg_outtrans(IObuff);
        msg_outtrans_attr(name, tagstack[i].fmark.fnum == curbuf->b_fnum
            ? hl_attr(HLF_D) : 0);
        free(name);
      }
      ui_flush();                    /* show one line at a time */
    }
    if (tagstackidx == tagstacklen)       /* idx at top of stack */
      MSG_PUTS("\n>");
  }
  
  
  
  /*
   * Compare two strings, for length "len", ignoring case the ASCII way.
   * return 0 for match, < 0 for smaller, > 0 for bigger
   * Make sure case is folded to uppercase in comparison (like for 'sort -f')
   */
  static int tag_strnicmp(char_u *s1, char_u *s2, size_t len)
  {
    int i;
  
    while (len > 0) {
      i = (int)TOUPPER_ASC(*s1) - (int)TOUPPER_ASC(*s2);
      if (i != 0)
        return i;                         /* this character different */
      if (*s1 == NUL)
        break;                            /* strings match until NUL */
      ++s1;
      ++s2;
      --len;
    }
    return 0;                             /* strings match */
  }
  
  
  /*
   * Extract info from the tag search pattern "pats->pat".
   */
  static void prepare_pats(pat_T *pats, int has_re)
  {
    pats->head = pats->pat;
    pats->headlen = pats->len;
    if (has_re) {
      /* When the pattern starts with '^' or "\\<", binary searching can be
       * used (much faster). */
      if (pats->pat[0] == '^')
        pats->head = pats->pat + 1;
      else if (pats->pat[0] == '\\' && pats->pat[1] == '<')
        pats->head = pats->pat + 2;
      if (pats->head == pats->pat)
        pats->headlen = 0;
      else
        for (pats->headlen = 0; pats->head[pats->headlen] != NUL;
             ++pats->headlen)
          if (vim_strchr((char_u *)(p_magic ? ".[~*\\$" : "\\$"),
                  pats->head[pats->headlen]) != NULL)
            break;
      if (p_tl != 0 && pats->headlen > p_tl)      /* adjust for 'taglength' */
        pats->headlen = p_tl;
    }
  
    if (has_re)
      pats->regmatch.regprog = vim_regcomp(pats->pat, p_magic ? RE_MAGIC : 0);
    else
      pats->regmatch.regprog = NULL;
  }
  
  /*
   * find_tags() - search for tags in tags files
   *
   * Return FAIL if search completely failed (*num_matches will be 0, *matchesp
   * will be NULL), OK otherwise.
   *
   * There is a priority in which type of tag is recognized.
   *
   *  6.	A static or global tag with a full matching tag for the current file.
   *  5.	A global tag with a full matching tag for another file.
   *  4.	A static tag with a full matching tag for another file.
   *  3.	A static or global tag with an ignore-case matching tag for the
   *	current file.
   *  2.	A global tag with an ignore-case matching tag for another file.
   *  1.	A static tag with an ignore-case matching tag for another file.
   *
   * Tags in an emacs-style tags file are always global.
   *
   * flags:
   * TAG_HELP	  only search for help tags
   * TAG_NAMES	  only return name of tag
   * TAG_REGEXP	  use "pat" as a regexp
   * TAG_NOIC	  don't always ignore case
   * TAG_KEEP_LANG  keep language
   */
  int 
  find_tags (
      char_u *pat,                       /* pattern to search for */
      int *num_matches,               /* return: number of matches found */
      char_u ***matchesp,                /* return: array of matches found */
      int flags,
      int mincount,                           /*  MAXCOL: find all matches
                                               other: minimal number of matches */
      char_u *buf_ffname                /* name of buffer for priority */
  )
  {
    FILE       *fp;
    char_u     *lbuf;                     /* line buffer */
    int lbuf_size = LSIZE;                /* length of lbuf */
    char_u     *tag_fname;                /* name of tag file */
    tagname_T tn;                         /* info for get_tagfname() */
    int first_file;                       /* trying first tag file */
    tagptrs_T tagp;
    int did_open = FALSE;                 /* did open a tag file */
    int stop_searching = FALSE;           /* stop when match found or error */
    int retval = FAIL;                    /* return value */
    int is_static;                        /* current tag line is static */
    int is_current;                       /* file name matches */
    int eof = FALSE;                      /* found end-of-file */
    char_u      *p;
    char_u      *s;
    int i;
    int tag_file_sorted = NUL;            /* !_TAG_FILE_SORTED value */
    struct tag_search_info        /* Binary search file offsets */
    {
      off_t low_offset;           /* offset for first char of first line that
                                     could match */
      off_t high_offset;          /* offset of char after last line that could
                                     match */
      off_t curr_offset;          /* Current file offset in search range */
      off_t curr_offset_used;       /* curr_offset used when skipping back */
      off_t match_offset;         /* Where the binary search found a tag */
      int low_char;               /* first char at low_offset */
      int high_char;              /* first char at high_offset */
    } search_info;
    off_t filesize;
    int tagcmp;
    off_t offset;
    int round;
    enum {
      TS_START,                   /* at start of file */
      TS_LINEAR                   /* linear searching forward, till EOF */
      , TS_BINARY,                /* binary searching */
      TS_SKIP_BACK,               /* skipping backwards */
      TS_STEP_FORWARD             /* stepping forwards */
    }   state;                    /* Current search state */
  
    int cmplen;
    int match;                    /* matches */
    int match_no_ic = 0;          /* matches with rm_ic == FALSE */
    int match_re;                 /* match with regexp */
    int matchoff = 0;
    int save_emsg_off;
  
  
    struct match_found {
      int len;                    /* nr of chars of match[] to be compared */
      char_u match[1];            /* actually longer */
    } *mfp, *mfp2;
    garray_T ga_match[MT_COUNT];
    int match_count = 0;                          /* number of matches found */
    char_u      **matches;
    int mtt;
    int help_save;
    int help_pri = 0;
    char_u      *help_lang_find = NULL;           /* lang to be found */
    char_u help_lang[3];                          /* lang of current tags file */
    char_u      *saved_pat = NULL;                /* copy of pat[] */
  
    pat_T orgpat;                         /* holds unconverted pattern info */
    vimconv_T vimconv;
  
    int findall = (mincount == MAXCOL || mincount == TAG_MANY);
    /* find all matching tags */
    int sort_error = FALSE;                       /* tags file not sorted */
    int linear;                                   /* do a linear search */
    int sortic = FALSE;                           /* tag file sorted in nocase */
    int line_error = FALSE;                       /* syntax error */
    int has_re = (flags & TAG_REGEXP);            /* regexp used */
    int help_only = (flags & TAG_HELP);
    int name_only = (flags & TAG_NAMES);
    int noic = (flags & TAG_NOIC);
    int get_it_again = FALSE;
    int use_cscope = (flags & TAG_CSCOPE);
    int verbose = (flags & TAG_VERBOSE);
  
    help_save = curbuf->b_help;
    orgpat.pat = pat;
    vimconv.vc_type = CONV_NONE;
  
    /*
     * Allocate memory for the buffers that are used
     */
    lbuf = xmalloc(lbuf_size);
    tag_fname = xmalloc(MAXPATHL + 1);
    for (mtt = 0; mtt < MT_COUNT; ++mtt)
      ga_init(&ga_match[mtt], (int)sizeof(struct match_found *), 100);
  
    STRCPY(tag_fname, "from cscope");             /* for error messages */
  
    /*
     * Initialize a few variables
     */
    if (help_only)                                /* want tags from help file */
      curbuf->b_help = true;                      /* will be restored later */
  
    orgpat.len = (int)STRLEN(pat);
    if (curbuf->b_help) {
      /* When "@ab" is specified use only the "ab" language, otherwise
       * search all languages. */
      if (orgpat.len > 3 && pat[orgpat.len - 3] == '@'
          && ASCII_ISALPHA(pat[orgpat.len - 2])
          && ASCII_ISALPHA(pat[orgpat.len - 1])) {
        saved_pat = vim_strnsave(pat, orgpat.len - 3);
        help_lang_find = &pat[orgpat.len - 2];
        orgpat.pat = saved_pat;
        orgpat.len -= 3;
      }
    }
    if (p_tl != 0 && orgpat.len > p_tl)           /* adjust for 'taglength' */
      orgpat.len = p_tl;
  
    save_emsg_off = emsg_off;
    emsg_off = TRUE;    /* don't want error for invalid RE here */
    prepare_pats(&orgpat, has_re);
    emsg_off = save_emsg_off;
    if (has_re && orgpat.regmatch.regprog == NULL)
      goto findtag_end;
  
    /* This is only to avoid a compiler warning for using search_info
     * uninitialised. */
    memset(&search_info, 0, (size_t)1);
  
    /*
     * When finding a specified number of matches, first try with matching
     * case, so binary search can be used, and try ignore-case matches in a
     * second loop.
     * When finding all matches, 'tagbsearch' is off, or there is no fixed
     * string to look for, ignore case right away to avoid going though the
     * tags files twice.
     * When the tag file is case-fold sorted, it is either one or the other.
     * Only ignore case when TAG_NOIC not used or 'ignorecase' set.
     */
    orgpat.regmatch.rm_ic = ((p_ic || !noic)
                             && (findall || orgpat.headlen == 0 || !p_tbs));
    for (round = 1; round <= 2; ++round) {
      linear = (orgpat.headlen == 0 || !p_tbs || round == 2);
  
      /*
       * Try tag file names from tags option one by one.
       */
      for (first_file = TRUE;
           use_cscope ||
           get_tagfname(&tn, first_file, tag_fname) == OK;
           first_file = FALSE) {
        /*
         * A file that doesn't exist is silently ignored.  Only when not a
         * single file is found, an error message is given (further on).
         */
        if (use_cscope)
          fp = NULL;          /* avoid GCC warning */
        else {
          if (curbuf->b_help) {
            /* Prefer help tags according to 'helplang'.  Put the
             * two-letter language name in help_lang[]. */
            i = (int)STRLEN(tag_fname);
            if (i > 3 && tag_fname[i - 3] == '-')
              STRCPY(help_lang, tag_fname + i - 2);
            else
              STRCPY(help_lang, "en");
  
            /* When searching for a specific language skip tags files
             * for other languages. */
            if (help_lang_find != NULL
                && STRICMP(help_lang, help_lang_find) != 0)
              continue;
  
            /* For CTRL-] in a help file prefer a match with the same
             * language. */
            if ((flags & TAG_KEEP_LANG)
                && help_lang_find == NULL
                && curbuf->b_fname != NULL
                && (i = (int)STRLEN(curbuf->b_fname)) > 4
                && curbuf->b_fname[i - 1] == 'x'
                && curbuf->b_fname[i - 4] == '.'
                && STRNICMP(curbuf->b_fname + i - 3, help_lang, 2) == 0)
              help_pri = 0;
            else {
              help_pri = 1;
              for (s = p_hlg; *s != NUL; ++s) {
                if (STRNICMP(s, help_lang, 2) == 0)
                  break;
                ++help_pri;
                if ((s = vim_strchr(s, ',')) == NULL)
                  break;
              }
              if (s == NULL || *s == NUL) {
                /* Language not in 'helplang': use last, prefer English,
                 * unless found already. */
                ++help_pri;
                if (STRICMP(help_lang, "en") != 0)
                  ++help_pri;
              }
            }
          }
  
          if ((fp = mch_fopen((char *)tag_fname, "r")) == NULL)
            continue;
  
          if (p_verbose >= 5) {
            verbose_enter();
            smsg((char_u *)_("Searching tags file %s"), tag_fname);
            verbose_leave();
          }
        }
        did_open = TRUE;      /* remember that we found at least one file */
  
        state = TS_START;     /* we're at the start of the file */
  
        /*
         * Read and parse the lines in the file one by one
         */
        for (;; ) {
          line_breakcheck();          /* check for CTRL-C typed */
          if ((flags & TAG_INS_COMP))     /* Double brackets for gcc */
            ins_compl_check_keys(30);
          if (got_int || compl_interrupted) {
            stop_searching = TRUE;
            break;
          }
          /* When mincount is TAG_MANY, stop when enough matches have been
           * found (for completion). */
          if (mincount == TAG_MANY && match_count >= TAG_MANY) {
            stop_searching = TRUE;
            retval = OK;
            break;
          }
          if (get_it_again)
            goto line_read_in;
          /*
           * For binary search: compute the next offset to use.
           */
          if (state == TS_BINARY) {
            offset = search_info.low_offset + ((search_info.high_offset
                                                - search_info.low_offset) / 2);
            if (offset == search_info.curr_offset)
              break;              /* End the binary search without a match. */
            else
              search_info.curr_offset = offset;
          }
          /*
           * Skipping back (after a match during binary search).
           */
          else if (state == TS_SKIP_BACK) {
            search_info.curr_offset -= LSIZE * 2;
            if (search_info.curr_offset < 0) {
              search_info.curr_offset = 0;
              rewind(fp);
              state = TS_STEP_FORWARD;
            }
          }
  
          /*
           * When jumping around in the file, first read a line to find the
           * start of the next line.
           */
          if (state == TS_BINARY || state == TS_SKIP_BACK) {
            /* Adjust the search file offset to the correct position */
            search_info.curr_offset_used = search_info.curr_offset;
  #ifdef HAVE_FSEEKO
            fseeko(fp, search_info.curr_offset, SEEK_SET);
  #else
            fseek(fp, (long)search_info.curr_offset, SEEK_SET);
  #endif
            eof = vim_fgets(lbuf, LSIZE, fp);
            if (!eof && search_info.curr_offset != 0) {
              /* The explicit cast is to work around a bug in gcc 3.4.2
               * (repeated below). */
              search_info.curr_offset = ftell(fp);
              if (search_info.curr_offset == search_info.high_offset) {
                /* oops, gone a bit too far; try from low offset */
  #ifdef HAVE_FSEEKO
                fseeko(fp, search_info.low_offset, SEEK_SET);
  #else
                fseek(fp, (long)search_info.low_offset, SEEK_SET);
  #endif
                search_info.curr_offset = search_info.low_offset;
              }
              eof = vim_fgets(lbuf, LSIZE, fp);
            }
            /* skip empty and blank lines */
            while (!eof && vim_isblankline(lbuf)) {
              search_info.curr_offset = ftell(fp);
              eof = vim_fgets(lbuf, LSIZE, fp);
            }
            if (eof) {
              /* Hit end of file.  Skip backwards. */
              state = TS_SKIP_BACK;
              search_info.match_offset = ftell(fp);
              search_info.curr_offset = search_info.curr_offset_used;
              continue;
            }
          }
          /*
           * Not jumping around in the file: Read the next line.
           */
          else {
            /* skip empty and blank lines */
            do {
              if (use_cscope)
                eof = cs_fgets(lbuf, LSIZE);
              else
                eof = vim_fgets(lbuf, LSIZE, fp);
            } while (!eof && vim_isblankline(lbuf));
  
            if (eof) {
              break;                                  /* end of file */
            }
          }
  line_read_in:
  
          if (vimconv.vc_type != CONV_NONE) {
            char_u  *conv_line;
            int len;
  
            /* Convert every line.  Converting the pattern from 'enc' to
             * the tags file encoding doesn't work, because characters are
             * not recognized. */
            conv_line = string_convert(&vimconv, lbuf, NULL);
            if (conv_line != NULL) {
              /* Copy or swap lbuf and conv_line. */
              len = (int)STRLEN(conv_line) + 1;
              if (len > lbuf_size) {
                free(lbuf);
                lbuf = conv_line;
                lbuf_size = len;
              } else {
                STRCPY(lbuf, conv_line);
                free(conv_line);
              }
            }
          }
  
  
  
          /*
           * When still at the start of the file, check for Emacs tags file
           * format, and for "not sorted" flag.
           */
          if (state == TS_START) {
            /* The header ends when the line sorts below "!_TAG_".  When
             * case is folded lower case letters sort before "_". */
            if (STRNCMP(lbuf, "!_TAG_", 6) <= 0
                || (lbuf[0] == '!' && ASCII_ISLOWER(lbuf[1]))) {
              if (STRNCMP(lbuf, "!_TAG_", 6) != 0)
                /* Non-header item before the header, e.g. "!" itself.
                 */
                goto parse_line;
  
              /*
               * Read header line.
               */
              if (STRNCMP(lbuf, "!_TAG_FILE_SORTED\t", 18) == 0)
                tag_file_sorted = lbuf[18];
              if (STRNCMP(lbuf, "!_TAG_FILE_ENCODING\t", 20) == 0) {
                /* Prepare to convert every line from the specified
                 * encoding to 'encoding'. */
                for (p = lbuf + 20; *p > ' ' && *p < 127; ++p)
                  ;
                *p = NUL;
                convert_setup(&vimconv, lbuf + 20, p_enc);
              }
  
              /* Read the next line.  Unrecognized flags are ignored. */
              continue;
            }
  
            /* Headers ends. */
  
            /*
             * When there is no tag head, or ignoring case, need to do a
             * linear search.
             * When no "!_TAG_" is found, default to binary search.  If
             * the tag file isn't sorted, the second loop will find it.
             * When "!_TAG_FILE_SORTED" found: start binary search if
             * flag set.
             * For cscope, it's always linear.
             */
            if (linear || use_cscope)
              state = TS_LINEAR;
            else if (tag_file_sorted == NUL)
              state = TS_BINARY;
            else if (tag_file_sorted == '1')
              state = TS_BINARY;
            else if (tag_file_sorted == '2') {
              state = TS_BINARY;
              sortic = TRUE;
              orgpat.regmatch.rm_ic = (p_ic || !noic);
            } else
              state = TS_LINEAR;
  
            if (state == TS_BINARY && orgpat.regmatch.rm_ic && !sortic) {
              /* Binary search won't work for ignoring case, use linear
               * search. */
              linear = TRUE;
              state = TS_LINEAR;
            }
  
            /*
             * When starting a binary search, get the size of the file and
             * compute the first offset.
             */
            if (state == TS_BINARY) {
              // Get the tag file size.
              if ((filesize = lseek(fileno(fp), (off_t)0L, SEEK_END)) <= 0) {
                state = TS_LINEAR;
              } else {
                lseek(fileno(fp), (off_t)0L, SEEK_SET);
  
                /* Calculate the first read offset in the file.  Start
                 * the search in the middle of the file. */
                search_info.low_offset = 0;
                search_info.low_char = 0;
                search_info.high_offset = filesize;
                search_info.curr_offset = 0;
                search_info.high_char = 0xff;
              }
              continue;
            }
          }
  
  parse_line:
          /*
           * Figure out where the different strings are in this line.
           * For "normal" tags: Do a quick check if the tag matches.
           * This speeds up tag searching a lot!
           */
          if (orgpat.headlen
              ) {
            tagp.tagname = lbuf;
            tagp.tagname_end = vim_strchr(lbuf, TAB);
            if (tagp.tagname_end == NULL)
            {
              if (vim_strchr(lbuf, NL) == NULL) {
                /* Truncated line, ignore it.  Has been reported for
                 * Mozilla JS with extremely long names. */
                if (p_verbose >= 5) {
                  verbose_enter();
                  MSG(_("Ignoring long line in tags file"));
                  verbose_leave();
                }
                if (state != TS_LINEAR) {
                  /* Avoid getting stuck. */
                  linear = TRUE;
                  state = TS_LINEAR;
  # ifdef HAVE_FSEEKO
                  fseeko(fp, search_info.low_offset, SEEK_SET);
  # else
                  fseek(fp, (long)search_info.low_offset, SEEK_SET);
  # endif
                }
                continue;
              }
  
              /* Corrupted tag line. */
              line_error = TRUE;
              break;
            }
  
            /*
             * Check for old style static tag: "file:tag file .."
             */
            tagp.fname = NULL;
            for (p = lbuf; p < tagp.tagname_end; ++p) {
              if (*p == ':') {
                if (tagp.fname == NULL)
                  tagp.fname = tagp.tagname_end + 1;
                if (       fnamencmp(lbuf, tagp.fname, p - lbuf) == 0
                           && tagp.fname[p - lbuf] == TAB
                           ) {
                  /* found one */
                  tagp.tagname = p + 1;
                  break;
                }
              }
            }
  
            /*
             * Skip this line if the length of the tag is different and
             * there is no regexp, or the tag is too short.
             */
            cmplen = (int)(tagp.tagname_end - tagp.tagname);
            if (p_tl != 0 && cmplen > p_tl)           /* adjust for 'taglength' */
              cmplen = p_tl;
            if (has_re && orgpat.headlen < cmplen)
              cmplen = orgpat.headlen;
            else if (state == TS_LINEAR && orgpat.headlen != cmplen)
              continue;
  
            if (state == TS_BINARY) {
              /*
               * Simplistic check for unsorted tags file.
               */
              i = (int)tagp.tagname[0];
              if (sortic)
                i = (int)TOUPPER_ASC(tagp.tagname[0]);
              if (i < search_info.low_char || i > search_info.high_char)
                sort_error = TRUE;
  
              /*
               * Compare the current tag with the searched tag.
               */
              if (sortic)
                tagcmp = tag_strnicmp(tagp.tagname, orgpat.head,
                    (size_t)cmplen);
              else
                tagcmp = STRNCMP(tagp.tagname, orgpat.head, cmplen);
  
              /*
               * A match with a shorter tag means to search forward.
               * A match with a longer tag means to search backward.
               */
              if (tagcmp == 0) {
                if (cmplen < orgpat.headlen)
                  tagcmp = -1;
                else if (cmplen > orgpat.headlen)
                  tagcmp = 1;
              }
  
              if (tagcmp == 0) {
                /* We've located the tag, now skip back and search
                 * forward until the first matching tag is found.
                 */
                state = TS_SKIP_BACK;
                search_info.match_offset = search_info.curr_offset;
                continue;
              }
              if (tagcmp < 0) {
                search_info.curr_offset = ftell(fp);
                if (search_info.curr_offset < search_info.high_offset) {
                  search_info.low_offset = search_info.curr_offset;
                  if (sortic)
                    search_info.low_char =
                      TOUPPER_ASC(tagp.tagname[0]);
                  else
                    search_info.low_char = tagp.tagname[0];
                  continue;
                }
              }
              if (tagcmp > 0
                  && search_info.curr_offset != search_info.high_offset) {
                search_info.high_offset = search_info.curr_offset;
                if (sortic)
                  search_info.high_char =
                    TOUPPER_ASC(tagp.tagname[0]);
                else
                  search_info.high_char = tagp.tagname[0];
                continue;
              }
  
              /* No match yet and are at the end of the binary search. */
              break;
            } else if (state == TS_SKIP_BACK)   {
              assert(cmplen >= 0);
              if (mb_strnicmp(tagp.tagname, orgpat.head, (size_t)cmplen) != 0)
                state = TS_STEP_FORWARD;
              else
                /* Have to skip back more.  Restore the curr_offset
                 * used, otherwise we get stuck at a long line. */
                search_info.curr_offset = search_info.curr_offset_used;
              continue;
            } else if (state == TS_STEP_FORWARD)   {
              assert(cmplen >= 0);
              if (mb_strnicmp(tagp.tagname, orgpat.head, (size_t)cmplen) != 0) {
                if ((off_t)ftell(fp) > search_info.match_offset)
                  break;                  /* past last match */
                else
                  continue;               /* before first match */
              }
            } else
            /* skip this match if it can't match */
            assert(cmplen >= 0);
            if (mb_strnicmp(tagp.tagname, orgpat.head, (size_t)cmplen) != 0)
              continue;
  
            /*
             * Can be a matching tag, isolate the file name and command.
             */
            if (tagp.fname == NULL)
              tagp.fname = tagp.tagname_end + 1;
            tagp.fname_end = vim_strchr(tagp.fname, TAB);
            tagp.command = tagp.fname_end + 1;
            if (tagp.fname_end == NULL)
              i = FAIL;
            else
              i = OK;
          } else
            i = parse_tag_line(lbuf,
                &tagp);
          if (i == FAIL) {
            line_error = TRUE;
            break;
          }
  
          /*
           * First try matching with the pattern literally (also when it is
           * a regexp).
           */
          cmplen = (int)(tagp.tagname_end - tagp.tagname);
          if (p_tl != 0 && cmplen > p_tl)             /* adjust for 'taglength' */
            cmplen = p_tl;
          /* if tag length does not match, don't try comparing */
          if (orgpat.len != cmplen)
            match = FALSE;
          else {
            if (orgpat.regmatch.rm_ic) {
              assert(cmplen >= 0);
              match = mb_strnicmp(tagp.tagname, orgpat.pat, (size_t)cmplen) == 0;
              if (match)
                match_no_ic = (STRNCMP(tagp.tagname, orgpat.pat,
                                   cmplen) == 0);
            } else
              match = (STRNCMP(tagp.tagname, orgpat.pat, cmplen) == 0);
          }
  
          /*
           * Has a regexp: Also find tags matching regexp.
           */
          match_re = FALSE;
          if (!match && orgpat.regmatch.regprog != NULL) {
            int cc;
  
            cc = *tagp.tagname_end;
            *tagp.tagname_end = NUL;
            match = vim_regexec(&orgpat.regmatch, tagp.tagname, (colnr_T)0);
            if (match) {
              matchoff = (int)(orgpat.regmatch.startp[0] - tagp.tagname);
              if (orgpat.regmatch.rm_ic) {
                orgpat.regmatch.rm_ic = FALSE;
                match_no_ic = vim_regexec(&orgpat.regmatch, tagp.tagname,
                    (colnr_T)0);
                orgpat.regmatch.rm_ic = TRUE;
              }
            }
            *tagp.tagname_end = cc;
            match_re = TRUE;
          }
  
          /*
           * If a match is found, add it to ga_match[].
           */
          if (match) {
            if (use_cscope) {
              /* Don't change the ordering, always use the same table. */
              mtt = MT_GL_OTH;
            } else {
              /* Decide in which array to store this match. */
              is_current = test_for_current(
                  tagp.fname, tagp.fname_end, tag_fname,
                  buf_ffname);
              {
                if (tagp.tagname != lbuf)
                  is_static = TRUE;               /* detected static tag before */
                else
                  is_static = test_for_static(&tagp);
              }
  
              /* decide in which of the sixteen tables to store this
               * match */
              if (is_static) {
                if (is_current)
                  mtt = MT_ST_CUR;
                else
                  mtt = MT_ST_OTH;
              } else {
                if (is_current)
                  mtt = MT_GL_CUR;
                else
                  mtt = MT_GL_OTH;
              }
              if (orgpat.regmatch.rm_ic && !match_no_ic)
                mtt += MT_IC_OFF;
              if (match_re)
                mtt += MT_RE_OFF;
            }
  
            /*
             * Add the found match in ga_match[mtt], avoiding duplicates.
             * Store the info we need later, which depends on the kind of
             * tags we are dealing with.
             */
            ga_grow(&ga_match[mtt], 1);
            {
              int len;
  
              if (help_only) {
  # define ML_EXTRA 3
                /*
                 * Append the help-heuristic number after the
                 * tagname, for sorting it later.
                 */
                *tagp.tagname_end = NUL;
                len = (int)(tagp.tagname_end - tagp.tagname);
                mfp = xmalloc(sizeof(struct match_found) + len + 10 + ML_EXTRA);
                /* "len" includes the language and the NUL, but
                 * not the priority. */
                mfp->len = len + ML_EXTRA + 1;
  #define ML_HELP_LEN 6
                p = mfp->match;
                STRCPY(p, tagp.tagname);
                p[len] = '@';
                STRCPY(p + len + 1, help_lang);
                sprintf((char *)p + len + 1 + ML_EXTRA, "%06d",
                    help_heuristic(tagp.tagname,
                        match_re ? matchoff : 0, !match_no_ic)
                    + help_pri
                    );
  
                *tagp.tagname_end = TAB;
              } else if (name_only)   {
                if (get_it_again) {
                  char_u *temp_end = tagp.command;
  
                  if (*temp_end == '/')
                    while (*temp_end && *temp_end != '\r'
                           && *temp_end != '\n'
                           && *temp_end != '$')
                      temp_end++;
  
                  if (tagp.command + 2 < temp_end) {
                    len = (int)(temp_end - tagp.command - 2);
                    mfp = xmalloc(sizeof(struct match_found) + len);
                    mfp->len = len + 1;                 /* include the NUL */
                    p = mfp->match;
                    STRLCPY(p, tagp.command + 2, len + 1);
                  } else
                    mfp = NULL;
                  get_it_again = FALSE;
                } else {
                  len = (int)(tagp.tagname_end - tagp.tagname);
                  mfp = xmalloc(sizeof(struct match_found) + len);
                  mfp->len = len + 1;               /* include the NUL */
                  p = mfp->match;
                  STRLCPY(p, tagp.tagname, len + 1);
  
                  /* if wanted, re-read line to get long form too */
                  if (State & INSERT)
                    get_it_again = p_sft;
                }
              } else {
                /* Save the tag in a buffer.
                 * Emacs tag: <mtt><tag_fname><NUL><ebuf><NUL><lbuf>
                 * other tag: <mtt><tag_fname><NUL><NUL><lbuf>
                 * without Emacs tags: <mtt><tag_fname><NUL><lbuf>
                 */
                len = (int)STRLEN(tag_fname)
                      + (int)STRLEN(lbuf) + 3;
                mfp = xmalloc(sizeof(struct match_found) + len);
                mfp->len = len;
                p = mfp->match;
                p[0] = mtt;
                STRCPY(p + 1, tag_fname);
  #ifdef BACKSLASH_IN_FILENAME
                /* Ignore differences in slashes, avoid adding
                 * both path/file and path\file. */
                slash_adjust(p + 1);
  #endif
                s = p + 1 + STRLEN(tag_fname) + 1;
                STRCPY(s, lbuf);
              }
  
              if (mfp != NULL) {
                /*
                 * Don't add identical matches.
                 * This can take a lot of time when finding many
                 * matches, check for CTRL-C now and then.
                 * Add all cscope tags, because they are all listed.
                 */
                if (use_cscope)
                  i = -1;
                else
                  for (i = ga_match[mtt].ga_len; --i >= 0 && !got_int; ) {
                    mfp2 = ((struct match_found **)
                            (ga_match[mtt].ga_data))[i];
                    if (mfp2->len == mfp->len
                        && memcmp(mfp2->match, mfp->match,
                            (size_t)mfp->len) == 0)
                      break;
                    line_breakcheck();
                  }
                if (i < 0) {
                  ((struct match_found **)(ga_match[mtt].ga_data))
                  [ga_match[mtt].ga_len++] = mfp;
                  ++match_count;
                } else
                  free(mfp);
              }
            }
          }
          if (use_cscope && eof)
            break;
        }   /* forever */
  
        if (line_error) {
          EMSG2(_("E431: Format error in tags file \"%s\""), tag_fname);
          if (!use_cscope)
            EMSGN(_("Before byte %" PRId64), ftell(fp));
          stop_searching = TRUE;
          line_error = FALSE;
        }
  
        if (!use_cscope)
          fclose(fp);
        if (vimconv.vc_type != CONV_NONE)
          convert_setup(&vimconv, NULL, NULL);
  
        tag_file_sorted = NUL;
        if (sort_error) {
          EMSG2(_("E432: Tags file not sorted: %s"), tag_fname);
          sort_error = FALSE;
        }
  
        /*
         * Stop searching if sufficient tags have been found.
         */
        if (match_count >= mincount) {
          retval = OK;
          stop_searching = TRUE;
        }
  
        if (stop_searching || use_cscope)
          break;
  
      }   /* end of for-each-file loop */
  
      if (!use_cscope)
        tagname_free(&tn);
  
      /* stop searching when already did a linear search, or when TAG_NOIC
       * used, and 'ignorecase' not set or already did case-ignore search */
      if (stop_searching || linear || (!p_ic && noic) || orgpat.regmatch.rm_ic)
        break;
      if (use_cscope)
        break;
      orgpat.regmatch.rm_ic = TRUE;       /* try another time while ignoring case */
    }
  
    if (!stop_searching) {
      if (!did_open && verbose)           /* never opened any tags file */
        EMSG(_("E433: No tags file"));
      retval = OK;                /* It's OK even when no tag found */
    }
  
  findtag_end:
    free(lbuf);
    vim_regfree(orgpat.regmatch.regprog);
    free(tag_fname);
  
    /*
     * Move the matches from the ga_match[] arrays into one list of
     * matches.  When retval == FAIL, free the matches.
     */
    if (retval == FAIL)
      match_count = 0;
  
    if (match_count > 0)
      matches = xmalloc(match_count * sizeof(char_u *));
    else
      matches = NULL;
    match_count = 0;
    for (mtt = 0; mtt < MT_COUNT; ++mtt) {
      for (int i = 0; i < ga_match[mtt].ga_len; ++i) {
        mfp = ((struct match_found **)(ga_match[mtt].ga_data))[i];
        if (matches == NULL)
          free(mfp);
        else {
          /* To avoid allocating memory again we turn the struct
           * match_found into a string.  For help the priority was not
           * included in the length. */
          memmove(mfp, mfp->match,
              (size_t)(mfp->len + (help_only ? ML_HELP_LEN : 0)));
          matches[match_count++] = (char_u *)mfp;
        }
      }
      ga_clear(&ga_match[mtt]);
    }
  
    *matchesp = matches;
    *num_matches = match_count;
  
    curbuf->b_help = help_save;
    free(saved_pat);
  
    return retval;
  }
  
  static garray_T tag_fnames = GA_EMPTY_INIT_VALUE;
  
  /*
   * Callback function for finding all "tags" and "tags-??" files in
   * 'runtimepath' doc directories.
   */
  static void found_tagfile_cb(char_u *fname, void *cookie)
  {
    GA_APPEND(char_u *, &tag_fnames, vim_strsave(fname));
  }
  
  #if defined(EXITFREE)
  void free_tag_stuff(void)
  {
    ga_clear_strings(&tag_fnames);
    do_tag(NULL, DT_FREE, 0, 0, 0);
    tag_freematch();
  
    if (ptag_entry.tagname) {
      free(ptag_entry.tagname);
      ptag_entry.tagname = NULL;
    }
  }
  
  #endif
  
  /*
   * Get the next name of a tag file from the tag file list.
   * For help files, use "tags" file only.
   *
   * Return FAIL if no more tag file names, OK otherwise.
   */
  int 
  get_tagfname (
      tagname_T *tnp,       /* holds status info */
      int first,              /* TRUE when first file name is wanted */
      char_u *buf       /* pointer to buffer of MAXPATHL chars */
  )
  {
    char_u              *fname = NULL;
    char_u              *r_ptr;
  
    if (first)
      memset(tnp, 0, sizeof(tagname_T));
  
    if (curbuf->b_help) {
      /*
       * For help files it's done in a completely different way:
       * Find "doc/tags" and "doc/tags-??" in all directories in
       * 'runtimepath'.
       */
      if (first) {
        ga_clear_strings(&tag_fnames);
        ga_init(&tag_fnames, (int)sizeof(char_u *), 10);
        do_in_runtimepath((char_u *)
            "doc/tags doc/tags-??"
            , TRUE, found_tagfile_cb, NULL);
      }
  
      if (tnp->tn_hf_idx >= tag_fnames.ga_len) {
        /* Not found in 'runtimepath', use 'helpfile', if it exists and
         * wasn't used yet, replacing "help.txt" with "tags". */
        if (tnp->tn_hf_idx > tag_fnames.ga_len || *p_hf == NUL)
          return FAIL;
        ++tnp->tn_hf_idx;
        STRCPY(buf, p_hf);
        STRCPY(path_tail(buf), "tags");
      } else
        STRLCPY(buf, ((char_u **)(tag_fnames.ga_data))[
              tnp->tn_hf_idx++], MAXPATHL);
      return OK;
    }
  
    if (first) {
      /* Init.  We make a copy of 'tags', because autocommands may change
       * the value without notifying us. */
      tnp->tn_tags = vim_strsave((*curbuf->b_p_tags != NUL)
          ? curbuf->b_p_tags : p_tags);
      tnp->tn_np = tnp->tn_tags;
    }
  
    /*
     * Loop until we have found a file name that can be used.
     * There are two states:
     * tnp->tn_did_filefind_init == FALSE: setup for next part in 'tags'.
     * tnp->tn_did_filefind_init == TRUE: find next file in this part.
     */
    for (;; ) {
      if (tnp->tn_did_filefind_init) {
        fname = vim_findfile(tnp->tn_search_ctx);
        if (fname != NULL)
          break;
  
        tnp->tn_did_filefind_init = FALSE;
      } else {
        char_u  *filename = NULL;
  
        /* Stop when used all parts of 'tags'. */
        if (*tnp->tn_np == NUL) {
          vim_findfile_cleanup(tnp->tn_search_ctx);
          tnp->tn_search_ctx = NULL;
          return FAIL;
        }
  
        /*
         * Copy next file name into buf.
         */
        buf[0] = NUL;
        (void)copy_option_part(&tnp->tn_np, buf, MAXPATHL - 1, " ,");
  
        r_ptr = vim_findfile_stopdir(buf);
        /* move the filename one char forward and truncate the
         * filepath with a NUL */
        filename = path_tail(buf);
        STRMOVE(filename + 1, filename);
        *filename++ = NUL;
  
        tnp->tn_search_ctx = vim_findfile_init(buf, filename,
            r_ptr, 100,
            FALSE,                   /* don't free visited list */
            FINDFILE_FILE,           /* we search for a file */
            tnp->tn_search_ctx, TRUE, curbuf->b_ffname);
        if (tnp->tn_search_ctx != NULL)
          tnp->tn_did_filefind_init = TRUE;
      }
    }
  
    STRCPY(buf, fname);
    free(fname);
    return OK;
  }
  
  /*
   * Free the contents of a tagname_T that was filled by get_tagfname().
   */
  void tagname_free(tagname_T *tnp)
  {
    free(tnp->tn_tags);
    vim_findfile_cleanup(tnp->tn_search_ctx);
    tnp->tn_search_ctx = NULL;
    ga_clear_strings(&tag_fnames);
  }
  
  /*
   * Parse one line from the tags file. Find start/end of tag name, start/end of
   * file name and start of search pattern.
   *
   * If is_etag is TRUE, tagp->fname and tagp->fname_end are not set.
   *
   * Return FAIL if there is a format error in this line, OK otherwise.
   */
  static int 
  parse_tag_line (
      char_u *lbuf,              /* line to be parsed */
      tagptrs_T *tagp
  )
  {
    char_u      *p;
  
    /* Isolate the tagname, from lbuf up to the first white */
    tagp->tagname = lbuf;
    p = vim_strchr(lbuf, TAB);
    if (p == NULL)
      return FAIL;
    tagp->tagname_end = p;
  
    /* Isolate file name, from first to second white space */
    if (*p != NUL)
      ++p;
    tagp->fname = p;
    p = vim_strchr(p, TAB);
    if (p == NULL)
      return FAIL;
    tagp->fname_end = p;
  
    /* find start of search command, after second white space */
    if (*p != NUL)
      ++p;
    if (*p == NUL)
      return FAIL;
    tagp->command = p;
  
    return OK;
  }
  
  /*
   * Check if tagname is a static tag
   *
   * Static tags produced by the older ctags program have the format:
   *	'file:tag  file  /pattern'.
   * This is only recognized when both occurrence of 'file' are the same, to
   * avoid recognizing "string::string" or ":exit".
   *
   * Static tags produced by the new ctags program have the format:
   *	'tag  file  /pattern/;"<Tab>file:'	    "
   *
   * Return TRUE if it is a static tag and adjust *tagname to the real tag.
   * Return FALSE if it is not a static tag.
   */
  static int test_for_static(tagptrs_T *tagp)
  {
    char_u      *p;
  
    int len;
  
    /*
     * Check for old style static tag: "file:tag file .."
     */
    len = (int)(tagp->fname_end - tagp->fname);
    p = tagp->tagname + len;
    if (       p < tagp->tagname_end
               && *p == ':'
               && fnamencmp(tagp->tagname, tagp->fname, len) == 0) {
      tagp->tagname = p + 1;
      return TRUE;
    }
  
    /*
     * Check for new style static tag ":...<Tab>file:[<Tab>...]"
     */
    p = tagp->command;
    while ((p = vim_strchr(p, '\t')) != NULL) {
      ++p;
      if (STRNCMP(p, "file:", 5) == 0)
        return TRUE;
    }
  
    return FALSE;
  }
  
  /*
   * Parse a line from a matching tag.  Does not change the line itself.
   *
   * The line that we get looks like this:
   * Emacs tag: <mtt><tag_fname><NUL><ebuf><NUL><lbuf>
   * other tag: <mtt><tag_fname><NUL><NUL><lbuf>
   * without Emacs tags: <mtt><tag_fname><NUL><lbuf>
   *
   * Return OK or FAIL.
   */
  static int 
  parse_match (
      char_u *lbuf,          /* input: matching line */
      tagptrs_T *tagp          /* output: pointers into the line */
  )
  {
    int retval;
    char_u      *p;
    char_u      *pc, *pt;
  
    tagp->tag_fname = lbuf + 1;
    lbuf += STRLEN(tagp->tag_fname) + 2;
  
    /* Find search pattern and the file name for non-etags. */
    retval = parse_tag_line(lbuf,
        tagp);
  
    tagp->tagkind = NULL;
    tagp->command_end = NULL;
  
    if (retval == OK) {
      /* Try to find a kind field: "kind:<kind>" or just "<kind>"*/
      p = tagp->command;
      if (find_extra(&p) == OK) {
        tagp->command_end = p;
        p += 2;           /* skip ";\"" */
        if (*p++ == TAB)
          while (ASCII_ISALPHA(*p)) {
            if (STRNCMP(p, "kind:", 5) == 0) {
              tagp->tagkind = p + 5;
              break;
            }
            pc = vim_strchr(p, ':');
            pt = vim_strchr(p, '\t');
            if (pc == NULL || (pt != NULL && pc > pt)) {
              tagp->tagkind = p;
              break;
            }
            if (pt == NULL)
              break;
            p = pt + 1;
          }
      }
      if (tagp->tagkind != NULL) {
        for (p = tagp->tagkind;
             *p && *p != '\t' && *p != '\r' && *p != '\n'; ++p)
          ;
        tagp->tagkind_end = p;
      }
    }
    return retval;
  }
  
  /*
   * Find out the actual file name of a tag.  Concatenate the tags file name
   * with the matching tag file name.
   * Returns an allocated string.
   */
  static char_u *tag_full_fname(tagptrs_T *tagp)
  {
    int c = *tagp->fname_end;
    *tagp->fname_end = NUL;
    char_u *fullname = expand_tag_fname(tagp->fname, tagp->tag_fname, FALSE);
    *tagp->fname_end = c;
  
    return fullname;
  }
  
  /*
   * Jump to a tag that has been found in one of the tag files
   *
   * returns OK for success, NOTAGFILE when file not found, FAIL otherwise.
   */
  static int 
  jumpto_tag (
      char_u *lbuf,              /* line from the tags file for this tag */
      int forceit,                    /* :ta with ! */
      int keep_help                  /* keep help flag (FALSE for cscope) */
  )
  {
    int save_secure;
    int save_magic;
    bool save_p_ws;
    int save_p_scs, save_p_ic;
    linenr_T save_lnum;
    int csave = 0;
    char_u      *str;
    char_u      *pbuf;                    /* search pattern buffer */
    char_u      *pbuf_end;
    char_u      *tofree_fname = NULL;
    char_u      *fname;
    tagptrs_T tagp;
    int retval = FAIL;
    int getfile_result;
    int search_options;
    int save_no_hlsearch;
    win_T       *curwin_save = NULL;
    char_u      *full_fname = NULL;
    int old_KeyTyped = KeyTyped;              /* getting the file may reset it */
    const int l_g_do_tagpreview = g_do_tagpreview;
  
    pbuf = xmalloc(LSIZE);
  
    /* parse the match line into the tagp structure */
    if (parse_match(lbuf, &tagp) == FAIL) {
      tagp.fname_end = NULL;
      goto erret;
    }
  
    /* truncate the file name, so it can be used as a string */
    csave = *tagp.fname_end;
    *tagp.fname_end = NUL;
    fname = tagp.fname;
  
    /* copy the command to pbuf[], remove trailing CR/NL */
    str = tagp.command;
    for (pbuf_end = pbuf; *str && *str != '\n' && *str != '\r'; ) {
      *pbuf_end++ = *str++;
    }
    *pbuf_end = NUL;
  
    {
      /*
       * Remove the "<Tab>fieldname:value" stuff; we don't need it here.
       */
      str = pbuf;
      if (find_extra(&str) == OK) {
        pbuf_end = str;
        *pbuf_end = NUL;
      }
    }
  
    /*
     * Expand file name, when needed (for environment variables).
     * If 'tagrelative' option set, may change file name.
     */
    fname = expand_tag_fname(fname, tagp.tag_fname, TRUE);
    tofree_fname = fname;         /* free() it later */
  
    /*
     * Check if the file with the tag exists before abandoning the current
     * file.  Also accept a file name for which there is a matching BufReadCmd
     * autocommand event (e.g., http://sys/file).
     */
    if (!os_file_exists(fname)
        && !has_autocmd(EVENT_BUFREADCMD, fname, NULL)
        ) {
      retval = NOTAGFILE;
      free(nofile_fname);
      nofile_fname = vim_strsave(fname);
      goto erret;
    }
  
    ++RedrawingDisabled;
  
  
    if (l_g_do_tagpreview != 0) {
      postponed_split = 0;        /* don't split again below */
      curwin_save = curwin;       /* Save current window */
  
      /*
       * If we are reusing a window, we may change dir when
       * entering it (autocommands) so turn the tag filename
       * into a fullpath
       */
      if (!curwin->w_p_pvw) {
        full_fname = FullName_save(fname, FALSE);
        fname = full_fname;
  
        /*
         * Make the preview window the current window.
         * Open a preview window when needed.
         */
        prepare_tagpreview(true);
      }
    }
  
    /* If it was a CTRL-W CTRL-] command split window now.  For ":tab tag"
     * open a new tab page. */
    if (postponed_split || cmdmod.tab != 0) {
      win_split(postponed_split > 0 ? postponed_split : 0,
          postponed_split_flags);
      RESET_BINDING(curwin);
    }
  
    if (keep_help) {
      /* A :ta from a help file will keep the b_help flag set.  For ":ptag"
       * we need to use the flag from the window where we came from. */
      if (l_g_do_tagpreview != 0)
        keep_help_flag = curwin_save->w_buffer->b_help;
      else
        keep_help_flag = curbuf->b_help;
    }
    getfile_result = getfile(0, fname, NULL, TRUE, (linenr_T)0, forceit);
    keep_help_flag = FALSE;
  
    if (getfile_result <= 0) {            /* got to the right file */
      curwin->w_set_curswant = TRUE;
      postponed_split = 0;
  
      save_secure = secure;
      secure = 1;
  #ifdef HAVE_SANDBOX
      ++sandbox;
  #endif
      save_magic = p_magic;
      p_magic = FALSE;            /* always execute with 'nomagic' */
      /* Save value of no_hlsearch, jumping to a tag is not a real search */
      save_no_hlsearch = no_hlsearch;
  
      /*
       * If 'cpoptions' contains 't', store the search pattern for the "n"
       * command.  If 'cpoptions' does not contain 't', the search pattern
       * is not stored.
       */
      if (vim_strchr(p_cpo, CPO_TAGPAT) != NULL)
        search_options = 0;
      else
        search_options = SEARCH_KEEP;
  
      /*
       * If the command is a search, try here.
       *
       * Reset 'smartcase' for the search, since the search pattern was not
       * typed by the user.
       * Only use do_search() when there is a full search command, without
       * anything following.
       */
      str = pbuf;
      if (pbuf[0] == '/' || pbuf[0] == '?')
        str = skip_regexp(pbuf + 1, pbuf[0], FALSE, NULL) + 1;
      if (str > pbuf_end - 1) {   /* search command with nothing following */
        save_p_ws = p_ws;
        save_p_ic = p_ic;
        save_p_scs = p_scs;
        p_ws = true;              /* need 'wrapscan' for backward searches */
        p_ic = FALSE;             /* don't ignore case now */
        p_scs = FALSE;
        save_lnum = curwin->w_cursor.lnum;
        curwin->w_cursor.lnum = 0;        /* start search before first line */
        if (do_search(NULL, pbuf[0], pbuf + 1, (long)1,
                search_options, NULL))
          retval = OK;
        else {
          int found = 1;
          int cc;
  
          /*
           * try again, ignore case now
           */
          p_ic = TRUE;
          if (!do_search(NULL, pbuf[0], pbuf + 1, (long)1,
                  search_options, NULL)) {
            /*
             * Failed to find pattern, take a guess: "^func  ("
             */
            found = 2;
            (void)test_for_static(&tagp);
            cc = *tagp.tagname_end;
            *tagp.tagname_end = NUL;
            sprintf((char *)pbuf, "^%s\\s\\*(", tagp.tagname);
            if (!do_search(NULL, '/', pbuf, (long)1,
                    search_options, NULL)) {
              /* Guess again: "^char * \<func  (" */
              sprintf((char *)pbuf, "^\\[#a-zA-Z_]\\.\\*\\<%s\\s\\*(",
                  tagp.tagname);
              if (!do_search(NULL, '/', pbuf, (long)1,
                      search_options, NULL))
                found = 0;
            }
            *tagp.tagname_end = cc;
          }
          if (found == 0) {
            EMSG(_("E434: Can't find tag pattern"));
            curwin->w_cursor.lnum = save_lnum;
          } else {
            /*
             * Only give a message when really guessed, not when 'ic'
             * is set and match found while ignoring case.
             */
            if (found == 2 || !save_p_ic) {
              MSG(_("E435: Couldn't find tag, just guessing!"));
              if (!msg_scrolled && msg_silent == 0) {
                ui_flush();
                os_delay(1000L, true);
              }
            }
            retval = OK;
          }
        }
        p_ws = save_p_ws;
        p_ic = save_p_ic;
        p_scs = save_p_scs;
  
        /* A search command may have positioned the cursor beyond the end
         * of the line.  May need to correct that here. */
        check_cursor();
      } else {
        curwin->w_cursor.lnum = 1;                /* start command in line 1 */
        do_cmdline_cmd(pbuf);
        retval = OK;
      }
  
      /*
       * When the command has done something that is not allowed make sure
       * the error message can be seen.
       */
      if (secure == 2)
        wait_return(TRUE);
      secure = save_secure;
      p_magic = save_magic;
  #ifdef HAVE_SANDBOX
      --sandbox;
  #endif
      /* restore no_hlsearch when keeping the old search pattern */
      if (search_options) {
        SET_NO_HLSEARCH(save_no_hlsearch);
      }
  
      /* Return OK if jumped to another file (at least we found the file!). */
      if (getfile_result == -1)
        retval = OK;
  
      if (retval == OK) {
        /*
         * For a help buffer: Put the cursor line at the top of the window,
         * the help subject will be below it.
         */
        if (curbuf->b_help)
          set_topline(curwin, curwin->w_cursor.lnum);
        if ((fdo_flags & FDO_TAG) && old_KeyTyped)
          foldOpenCursor();
      }
  
      if (l_g_do_tagpreview != 0
          && curwin != curwin_save && win_valid(curwin_save)) {
        /* Return cursor to where we were */
        validate_cursor();
        redraw_later(VALID);
        win_enter(curwin_save, true);
      }
  
      --RedrawingDisabled;
    } else {
      --RedrawingDisabled;
      if (postponed_split) {              /* close the window */
        win_close(curwin, FALSE);
        postponed_split = 0;
      }
    }
  
  erret:
    g_do_tagpreview = 0;   /* For next time */
    if (tagp.fname_end != NULL)
      *tagp.fname_end = csave;
    free(pbuf);
    free(tofree_fname);
    free(full_fname);
  
    return retval;
  }
  
  /*
   * If "expand" is TRUE, expand wildcards in fname.
   * If 'tagrelative' option set, change fname (name of file containing tag)
   * according to tag_fname (name of tag file containing fname).
   * Returns a pointer to allocated memory.
   */
  static char_u *expand_tag_fname(char_u *fname, char_u *tag_fname, int expand)
  {
    char_u      *p;
    char_u      *expanded_fname = NULL;
    expand_T xpc;
  
    /*
     * Expand file name (for environment variables) when needed.
     */
    if (expand && mch_has_wildcard(fname)) {
      ExpandInit(&xpc);
      xpc.xp_context = EXPAND_FILES;
      expanded_fname = ExpandOne(&xpc, (char_u *)fname, NULL,
          WILD_LIST_NOTFOUND|WILD_SILENT, WILD_EXPAND_FREE);
      if (expanded_fname != NULL)
        fname = expanded_fname;
    }
  
    char_u *retval;
    if ((p_tr || curbuf->b_help)
        && !vim_isAbsName(fname)
        && (p = path_tail(tag_fname)) != tag_fname) {
      retval = xmalloc(MAXPATHL);
      STRCPY(retval, tag_fname);
      STRLCPY(retval + (p - tag_fname), fname,
          MAXPATHL - (p - tag_fname));
      /*
       * Translate names like "src/a/../b/file.c" into "src/b/file.c".
       */
      simplify_filename(retval);
    } else
      retval = vim_strsave(fname);
  
    free(expanded_fname);
  
    return retval;
  }
  
  /*
   * Check if we have a tag for the buffer with name "buf_ffname".
   * This is a bit slow, because of the full path compare in path_full_compare().
   * Return TRUE if tag for file "fname" if tag file "tag_fname" is for current
   * file.
   */
  static int test_for_current(char_u *fname, char_u *fname_end, char_u *tag_fname, char_u *buf_ffname)
  {
    int c;
    int retval = FALSE;
    char_u  *fullname;
  
    if (buf_ffname != NULL) {     /* if the buffer has a name */
      {
        c = *fname_end;
        *fname_end = NUL;
      }
      fullname = expand_tag_fname(fname, tag_fname, TRUE);
      retval = (path_full_compare(fullname, buf_ffname, TRUE) & kEqualFiles);
      free(fullname);
      *fname_end = c;
    }
  
    return retval;
  }
  
  /*
   * Find the end of the tagaddress.
   * Return OK if ";\"" is following, FAIL otherwise.
   */
  static int find_extra(char_u **pp)
  {
    char_u      *str = *pp;
  
    /* Repeat for addresses separated with ';' */
    for (;; ) {
      if (VIM_ISDIGIT(*str))
        str = skipdigits(str);
      else if (*str == '/' || *str == '?') {
        str = skip_regexp(str + 1, *str, FALSE, NULL);
        if (*str != **pp)
          str = NULL;
        else
          ++str;
      } else
        str = NULL;
      if (str == NULL || *str != ';'
          || !(VIM_ISDIGIT(str[1]) || str[1] == '/' || str[1] == '?'))
        break;
      ++str;      /* skip ';' */
    }
  
    if (str != NULL && STRNCMP(str, ";\"", 2) == 0) {
      *pp = str;
      return OK;
    }
    return FAIL;
  }
  
  int 
  expand_tags (
      int tagnames,                   /* expand tag names */
      char_u *pat,
      int *num_file,
      char_u ***file
  )
  {
    int i;
    int c;
    int tagnmflag;
    char_u tagnm[100];
    tagptrs_T t_p;
    int ret;
  
    if (tagnames)
      tagnmflag = TAG_NAMES;
    else
      tagnmflag = 0;
    if (pat[0] == '/')
      ret = find_tags(pat + 1, num_file, file,
          TAG_REGEXP | tagnmflag | TAG_VERBOSE,
          TAG_MANY, curbuf->b_ffname);
    else
      ret = find_tags(pat, num_file, file,
          TAG_REGEXP | tagnmflag | TAG_VERBOSE | TAG_NOIC,
          TAG_MANY, curbuf->b_ffname);
    if (ret == OK && !tagnames) {
      /* Reorganize the tags for display and matching as strings of:
       * "<tagname>\0<kind>\0<filename>\0"
       */
      for (i = 0; i < *num_file; i++) {
        parse_match((*file)[i], &t_p);
        c = (int)(t_p.tagname_end - t_p.tagname);
        memmove(tagnm, t_p.tagname, (size_t)c);
        tagnm[c++] = 0;
        tagnm[c++] = (t_p.tagkind != NULL && *t_p.tagkind)
                     ? *t_p.tagkind : 'f';
        tagnm[c++] = 0;
        memmove((*file)[i] + c, t_p.fname, t_p.fname_end - t_p.fname);
        (*file)[i][c + (t_p.fname_end - t_p.fname)] = 0;
        memmove((*file)[i], tagnm, (size_t)c);
      }
    }
    return ret;
  }
  
  
  /*
   * Add a tag field to the dictionary "dict".
   * Return OK or FAIL.
   */
  static int 
  add_tag_field (
      dict_T *dict,
      char *field_name,
      char_u *start,                 /* start of the value */
      char_u *end                   /* after the value; can be NULL */
  )
  {
    int len = 0;
    int retval;
  
    /* check that the field name doesn't exist yet */
    if (dict_find(dict, (char_u *)field_name, -1) != NULL) {
      if (p_verbose > 0) {
        verbose_enter();
        smsg((char_u *)_("Duplicate field name: %s"), field_name);
        verbose_leave();
      }
      return FAIL;
    }
    char_u *buf = xmalloc(MAXPATHL);
    if (start != NULL) {
      if (end == NULL) {
        end = start + STRLEN(start);
        while (end > start && (end[-1] == '\r' || end[-1] == '\n'))
          --end;
      }
      len = (int)(end - start);
      if (len > MAXPATHL - 1)
        len = MAXPATHL - 1;
      STRLCPY(buf, start, len + 1);
    }
    buf[len] = NUL;
    retval = dict_add_nr_str(dict, field_name, 0L, buf);
    free(buf);
    return retval;
  }
  
  /*
   * Add the tags matching the specified pattern to the list "list"
   * as a dictionary
   */
  int get_tags(list_T *list, char_u *pat)
  {
    int num_matches, i, ret;
    char_u      **matches, *p;
    char_u      *full_fname;
    dict_T      *dict;
    tagptrs_T tp;
    long is_static;
  
    ret = find_tags(pat, &num_matches, &matches,
        TAG_REGEXP | TAG_NOIC, (int)MAXCOL, NULL);
    if (ret == OK && num_matches > 0) {
      for (i = 0; i < num_matches; ++i) {
        int parse_result = parse_match(matches[i], &tp);
        assert(parse_result == OK);
        is_static = test_for_static(&tp);
  
        /* Skip pseudo-tag lines. */
        if (STRNCMP(tp.tagname, "!_TAG_", 6) == 0)
          continue;
  
        dict = dict_alloc();
        list_append_dict(list, dict);
  
        full_fname = tag_full_fname(&tp);
        if (add_tag_field(dict, "name", tp.tagname, tp.tagname_end) == FAIL
            || add_tag_field(dict, "filename", full_fname,
                NULL) == FAIL
            || add_tag_field(dict, "cmd", tp.command,
                tp.command_end) == FAIL
            || add_tag_field(dict, "kind", tp.tagkind,
                tp.tagkind ? tp.tagkind_end : NULL) == FAIL
            || dict_add_nr_str(dict, "static", is_static, NULL) == FAIL)
          ret = FAIL;
  
        free(full_fname);
  
        if (tp.command_end != NULL) {
          for (p = tp.command_end + 3;
               *p != NUL && *p != '\n' && *p != '\r'; ++p) {
            if (p == tp.tagkind || (p + 5 == tp.tagkind
                                    && STRNCMP(p, "kind:", 5) == 0))
              /* skip "kind:<kind>" and "<kind>" */
              p = tp.tagkind_end - 1;
            else if (STRNCMP(p, "file:", 5) == 0)
              /* skip "file:" (static tag) */
              p += 4;
            else if (!vim_iswhite(*p)) {
              char_u  *s, *n;
              int len;
  
              /* Add extra field as a dict entry.  Fields are
               * separated by Tabs. */
              n = p;
              while (*p != NUL && *p >= ' ' && *p < 127 && *p != ':')
                ++p;
              len = (int)(p - n);
              if (*p == ':' && len > 0) {
                s = ++p;
                while (*p != NUL && *p >= ' ')
                  ++p;
                n[len] = NUL;
                if (add_tag_field(dict, (char *)n, s, p) == FAIL)
                  ret = FAIL;
                n[len] = ':';
              } else
                /* Skip field without colon. */
                while (*p != NUL && *p >= ' ')
                  ++p;
              if (*p == NUL)
                break;
            }
          }
        }
  
        free(matches[i]);
      }
      free(matches);
    }
    return ret;
  }
  