Re: segmentation fault displaying etc/HELLO on Windows

["Juanma Barranquero" <lekktu@gmail.com>]

On Wed, Jul 30, 2008 at 08:48, Jason Rumney <jasonr@gnu.org> wrote:

>> Program received signal SIGSEGV, Segmentation fault.
>> 0x011ea1ff in w32_compute_glyph_string_overhangs (s=0x82eaf0) at w32term.c:1194
>> 1194          font->driver->text_extents (font, code, s->nchars, &metrics);
>> (gdb) bt
>> #0  0x011ea1ff in w32_compute_glyph_string_overhangs (s=0x82eaf0) at
>> w32term.c:1194

Hmm. I hate heisenbugs.

1) The backtrace above was at home, rebuilding (but not
bootstrapping), with system-configuration-options "--with-gcc (4.3)
--cflags -DENABLE_CHECKING=1 -DSITELOAD_PURESIZE_EXTRA=200000
-IC:/emacs/build/include -fno-crossjumping".

2) However, at work, after bootstrapping and with the same
system-configuration-options, I get this backtrace:

Program received signal SIGSEGV, Segmentation fault.
x_produce_glyphs (it=0x82e08c) at xdisp.c:19561
19561         PREPARE_FACE_FOR_DISPLAY (f, face);
(gdb) bt
#0  x_produce_glyphs (it=0x82e08c) at xdisp.c:19561
#1  0x0103b097 in display_line (it=0x82e08c) at xdisp.c:16662
#2  0x0103fbe6 in try_window (window=49766404, pos={charpos = 1,
bytepos = 1}, check_margins=1) at xdisp.c:14073
#3  0x01053f16 in redisplay_window (window=49766404,
just_this_one_p=0) at xdisp.c:13691
#4  0x01055fd9 in redisplay_window_0 (window=49766404) at xdisp.c:12276
#5  0x01018d91 in internal_condition_case_1 (bfun=0x1055fb6
<redisplay_window_0>, arg=49766404, handlers=47498501,
    hfun=0x1023dce <redisplay_window_error>) at eval.c:1559
#6  0x0102db3d in redisplay_windows (window=34) at xdisp.c:12255
#7  0x010474fd in redisplay_internal (preserve_echo_area=<value
optimized out>) at xdisp.c:11821
#8  0x0108a279 in read_char (commandflag=1, nmaps=3, maps=0x82fb70,
prev_event=47515649, used_mouse_menu=0x82fc34,
    end_time=0x0) at keyboard.c:2680
#9  0x0108e8ca in read_key_sequence (keybuf=0x82fcd4, bufsize=30,
prompt=47515649, dont_downcase_last=0,
    can_return_switch_frame=1, fix_current_buffer=1) at keyboard.c:9406
#10 0x01091a3d in command_loop_1 () at keyboard.c:1646
#11 0x01019016 in internal_condition_case (bfun=0x10917af
<command_loop_1>, handlers=47579377,
    hfun=0x1088a16 <cmd_error>) at eval.c:1511
#12 0x01087d2b in command_loop_2 () at keyboard.c:1362
#13 0x010190c0 in internal_catch (tag=47575449, func=0x1087d08
<command_loop_2>, arg=47515649) at eval.c:1247
#14 0x0108885b in command_loop () at keyboard.c:1341
#15 0x01088baf in recursive_edit_1 () at keyboard.c:950
#16 0x01088d1a in Frecursive_edit () at keyboard.c:1012
#17 0x01002c41 in main (argc=2, argv=0xa841e0) at emacs.c:1749

3) So I thought, let's do a non-optimizing build. This time I
bootstrapped (at work) with system-configuration-options "--with-gcc
(4.3) --no-opt --cflags -DENABLE_CHECKING=1
-DSITELOAD_PURESIZE_EXTRA=200000 -IC:/emacs/build/include". Now Emacs
does *not* crash.

All compilations were done with gcc (GCC) 4.3.0 20080305
(alpha-testing) mingw-20080502

Any pointer about how to debug this?

  Juanma