bug#10357: 24.0.92; etags misses C tags due to brackets

[Eli Zaretskii]

 cd src
 ../lib-src/etags xdisp.c -o xdisp.TAGS

Then look at xdisp.TAGS and you will see many functions missing from
the tags table.  Specifically, all the functions between lines 9097
and 21242 are not tagged.  Here's the relevant excerpt from the tags
table:

  in_display_vector_p ^?9025,284143
  add_to_log ^?9042,284592
  message_log_maybe_newline ^?9079,285427
  message_dolog ^?9096,285971
  display_count_lines ^?21243,659558
  display_string ^?21385,663522

Note the gap between line number 9096 and 21243.  This misses a large
number of functions that are actually present in xdisp.c.

What causes that is this fragment from message_dolog:

                      char dupstr[sizeof " [ times]"
                                  + INT_STRLEN_BOUND (printmax_t)];

If you remove it, the problem goes away.

Looking at the code in etags.c:C_entries, I think that the problem
might be here:

      else if (bracketlev > 0)
        {
          switch (c)
            {
            case ']':
              if (--bracketlev > 0)
                continue;
              break;
            case '\0':
              CNL_SAVE_DEFINEDEF ();
              break;
            }
          continue;
        }

This seems to ignore everything except ']' inside brackets [], but it
does not pay attention to strings, comments, 'c' character constants
etc. that can happen inside brackets, and which can also include
bracket characters.


In GNU Emacs 24.0.92.1 (i386-mingw-nt5.1.2600)
 of 2011-12-02 on HOME-C4E4A596F7
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENU
  value of $XMODIFIERS: nil
  locale-coding-system: cp1255
  default enable-multibyte-characters: t

Major mode: Mail

Minor modes in effect:
  shell-dirtrack-mode: t
  auto-fill-function: mail-mode-auto-fill
  flyspell-mode: t
  diff-auto-refine-mode: t
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  show-paren-mode: t
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  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  temp-buffer-resize-mode: t
  line-number-mode: t
  abbrev-mode: t

Recent input:
C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-z C-z C-z C-z C-z C-z C-z C-x b <return> 
C-SPC C-u 2 1 2 4 3 C-x g <prior> <prior> <prior> <prior> 
<prior> <prior> <prior> <prior> <prior> C-z C-z C-z 
C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z <next> 
<prior> C-x C-x C-x b <return> M-z M-z M-z M-z M-z 
M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z 
M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z 
M-z M-z M-z M-z M-z M-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-z C-z M-z M-z M-z M-z M-z M-z M-z M-z M-z 
M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z M-z 
M-z M-z <next> <down> <down> <down> <down> <down> <down> 
<down> <down> <down> <down> <down> <down> <down> <down> 
<down> <C-right> <right> <right> C-r C-w C-r <M-left> 
<prior> C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-x C-x <M-left> <prior> <prior> <prior> <next> 
<next> <next> <next> <next> <next> <prior> <next> <next> 
<next> <next> <next> <next> <prior> <next> <next> <next> 
<next> <next> <next> <prior> <prior> <prior> <prior> 
<prior> <prior> <prior> <prior> <prior> <prior> <prior> 
<prior> <prior> C-z C-z C-z C-z C-z C-z C-z C-z C-z 
C-z C-z C-z C-z <switch-frame> <switch-frame> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <switch-frame> 
M-x r e p C-g <help-echo> <switch-frame> <switch-frame> 
<help-echo> <help-echo> <help-echo> <switch-frame> 
<switch-frame> <help-echo> <switch-frame> <help-echo> 
M-x r e p o r t - e m <tab> <return>

Recent messages:
Saving file d:/gnu/bzr/emacs/trunk/src/xdisp.c...
Wrote d:/gnu/bzr/emacs/trunk/src/xdisp.c
Undo!
Saving file d:/gnu/bzr/emacs/trunk/src/xdisp.c...
Wrote d:/gnu/bzr/emacs/trunk/src/xdisp.c
Undo!
Saving file d:/gnu/bzr/emacs/trunk/src/xdisp.c...
Wrote d:/gnu/bzr/emacs/trunk/src/xdisp.c
Mark set [4 times]
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