find-tag
Submitter-Id: net
Originator: Stephan Wefing
Organization: none
Confidential: no
Synopsis: bugs in find-tag
Severity: non-critical
Priority: low
Category: auxiliary
Class: change-request
Release: gnats-3.101
Environment:
System: Linux kato 2.2.10-smp #8 SMP Fri Sep 17 16:45:09 CEST 1999 i686 unknown
Architecture: i686
Description:
(1) in contrast to emacs 20.3 the find-tag function
of xemacs 20.4 cannot
find tags associated with c/c++ struct/union/class members like
"stack_s::nof_objects". Such tags are generated by the gnu etags program
if the "--members" flag is set.
(2) in contrast to emacs 20.3 the find-tag function of xemacs 20.4 may fail
to find the definition of a type directly.
How-To-Repeat:
(1) consider the file "include.h" which
contains the following single line:
struct abc_s {int counter;};
calling the gnu etags program with
/usr/bin/X11/etags -C --members -S include.h
gives the following TAGS file:
^L
include.h,70
struct abc_s ^?abc_s^A1,0
struct abc_s {int counter;^?abc_s::counter^A1,0
(here i substituted each cntrl character by 2 ascii characters for transport
via email). passing "abc_s::counter" to the find-tag command gives the message
"No entries matching abc_s::counter".
(2) consider the file etags_test.h containing the single line
typdef struct {int i;} obj_t;
and a file etags_test.c containing the two following lines:
#include "etags_test.h"
typedef struct abs_s {obj_t o;} abs_t;
calling the gnu etags program with
/usr/bin/X11/etags -C --members -S etags_test.c etags_test.h
gives the following TAGS file:
^L
etags_test.c,83
typedef struct abs_s ^?abs_s^A2,24
typedef struct abs_s {obj_t o;} abs_t;^?abs_t^A2,24
^L
etags_test.h,41
typedef struct {int i;} obj_t;^?obj_t^A1,0
passing "obj_t" as a tag to xemacs' find-tag command positions the curser
first to the typdef statement in etags_test.c, whereas emacs first positions
to the correct typedef statement in etags_test.h. in both cases i use the same
TAGS file. i admit that this example is fairly artificial. however, the
problem may become really disturbing for real life code, especially if you use
other etags programs like that of darren hiebert
(http://darren.hiebert.com/ctags/index.html). the problem is a consequence of
the fact that (x)emacs does not only scan the tag fields of a TAGS file but
also its context fields. it would be very useful if one could direct (x)emacs
to scan only the tag fields of a TAGS file.
Fix:
--=-=-=--