X11 debugging pt.3

$ tar zxf X11libs-16.tar.gz

$ cd X11libs-16

$ grep -r XGetMotionEvents *

[...]

libX11/libX11-1.1.2/src/GetMoEv.c:XTimeCoord *XGetMotionEvents(

[...]

Now, we know that XGetMotionEvents is in libX11, so let's rebuild that.

bbyer:X11libs-16 bbyer$ cd libX11/

bbyer:libX11 bbyer$ ls -l

total 8

-rw-r--r-- 1 bbyer admin 35 Mar 30 2007 conf_flags

drwxr-xr-x 30 bbyer admin 1020 Jun 3 21:45 libX11-1.1.2

bbyer:libX11 bbyer$ cat conf_flags

--disable-xf86bigfont --without-xcbbbyer:libX11 bbyer$ (oops, no newline :/)

$ cd libX11-1.1.2

CFLAGS="-g3" will enable debugging symbols:

bbyer:libX11-1.1.2 bbyer$ CFLAGS="-g3" ./configure --prefix=/usr/X11 --disable-xf86bigfont --without-xcb

checking for a BSD-compatible install... /usr/bin/install -c

checking whether build environment is sane... yes

[...]

bbyer:libX11-1.1.2 bbyer$ make

Making all in include

make[1]: Nothing to be done for `all'.

Making all in modules

[...]

(expect this to take 15-30 minutes -- libX11 is the second-largest module!)

bbyer:libX11-1.1.2 bbyer$ sudo cp /usr/X11/lib/libX11.6.2.0.dylib /usr/X11/lib/libX11.6.2.0.dylib.old

bbyer:libX11-1.1.2 bbyer$ sudo make install

Now, repeat the above steps with gimp and gdb. The only problem is, with this configuration I can't get it to crash, so I can't get a backtrace.

What we need is a way to get debugging symbols without recompiling. dSYMs to the rescue! Apple's build system extracts debugging symbols from all binaries using dsymutil, and then "strips" them to save space. I have placed all of the dSYM bundles for X11 here:

http://people.freedesktop.org/~bbyer/x11app/debug_symbols_for_leopard/

(First, copy back your old libX11!)

Here's how you use them:

bbyer:libX11-1.1.2 bbyer$ cd ~/X11-playground/

bbyer:X11-playground bbyer$ curl -LO http://people.freedesktop.org/~bbyer/x11app/debug_symbols_for_leopard/X11libs-16/libX11.6.dylib.dSYM.tar.bz2

bbyer:X11-playground bbyer$ tar jxf libX11.6.dylib.dSYM.tar.bz2

[switch to first Terminal]

bbyer:~ bbyer$ /Volumes/GIMP/Gimp.app/Contents/Resources/bin/gimp --sync

[switch to second Terminal]

bbyer:X11-playground bbyer$ gdb attach 15031

GNU gdb 6.3.50-20050815 (Apple version gdb-768) (Tue Oct 2 04:07:49 UTC 2007)

[...]

(gdb) break gdk_x_error

Breakpoint 1 at 0xa45294

(gdb) cont

Continuing.

References:
	>X11 debugging pt.1 (From: Ben Byer <email@hidden>)
	>Re: X11 debugging pt.2 (From: Ben Byer <email@hidden>)