Re: Debugging propagated events
I added some logic and after that I got a warning that there is a mismatch between cairo_save and cairo_restore. So I fixed that and I got it working. The cairo logic was faulty all the time but only some new lines of code triggered that warning. So I guess I was just lucky that I stopped debugging for a moment and added those few lines. On 11/29/16 03:13, Jim Charlton wrote: > In Gtkmm (C++) you can overload the on_draw() function with your own. > This might give you a foothold in the on_draw() routine that is called > after a redraw event occurs. I guess in GTK you would have to connect a > callback function to the "draw" signal. Might help.?? > > jim... > > > On 2016-11-28 04:50 PM, zahlenm...@gmx.de wrote: >> This was one of the first things I did. Debug compilation option, debug >> CFLAGS, no stripping - without a change. The backtrace only shows 3 >> lines, my draw function and two from libc. >> The faulty address is not null. But the segfault happens after the >> return where all local variables are no longer in scope, and the >> addresses of the widget and the cairo context are valid. >> >> On 11/29/16 00:44, Alfonso Arbona Gimeno wrote: >>> Hi, >>> >>> Why don't you link against the debug version of the library so that it >>> shows you the complete stack? >>> It will give you some extra clues on why the segfault is happening. >>> >>> Regards, >>> Alfonso Arbona >>> >>> On November 29, 2016 6:17:05 AM GMT+09:00, zahlenm...@gmx.de wrote: >>> >>> For a custom widget I have a draw function. I do some drawing >>> there and >>> when I am finished I return FALSE to let the parent draw. >>> Immediately >>> after the return statement I get a segfault. gdb's backtrace >>> only shows >>> my draw function and an address I cannot associate to any object. >>> Are there some general tricks how to debug such errors? >>> >>> Kind regards >>> >>> >>> >>> gtk-app-devel-list mailing list >>> gtk-app-devel-list@gnome.org >>> https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list >>> >> ___ >> gtk-app-devel-list mailing list >> gtk-app-devel-list@gnome.org >> https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list > > > ___ > gtk-app-devel-list mailing list > gtk-app-devel-list@gnome.org > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Debugging propagated events
In Gtkmm (C++) you can overload the on_draw() function with your own. This might give you a foothold in the on_draw() routine that is called after a redraw event occurs. I guess in GTK you would have to connect a callback function to the "draw" signal. Might help.?? jim... On 2016-11-28 04:50 PM, zahlenm...@gmx.de wrote: This was one of the first things I did. Debug compilation option, debug CFLAGS, no stripping - without a change. The backtrace only shows 3 lines, my draw function and two from libc. The faulty address is not null. But the segfault happens after the return where all local variables are no longer in scope, and the addresses of the widget and the cairo context are valid. On 11/29/16 00:44, Alfonso Arbona Gimeno wrote: Hi, Why don't you link against the debug version of the library so that it shows you the complete stack? It will give you some extra clues on why the segfault is happening. Regards, Alfonso Arbona On November 29, 2016 6:17:05 AM GMT+09:00, zahlenm...@gmx.de wrote: For a custom widget I have a draw function. I do some drawing there and when I am finished I return FALSE to let the parent draw. Immediately after the return statement I get a segfault. gdb's backtrace only shows my draw function and an address I cannot associate to any object. Are there some general tricks how to debug such errors? Kind regards gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Debugging propagated events
Hi, Why don't you link against the debug version of the library so that it shows you the complete stack? It will give you some extra clues on why the segfault is happening. Regards, Alfonso Arbona On November 29, 2016 6:17:05 AM GMT+09:00, zahlenm...@gmx.de wrote: >For a custom widget I have a draw function. I do some drawing there and >when I am finished I return FALSE to let the parent draw. Immediately >after the return statement I get a segfault. gdb's backtrace only shows >my draw function and an address I cannot associate to any object. >Are there some general tricks how to debug such errors? > >Kind regards >___ >gtk-app-devel-list mailing list >gtk-app-devel-list@gnome.org >https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Debugging propagated events
This was one of the first things I did. Debug compilation option, debug CFLAGS, no stripping - without a change. The backtrace only shows 3 lines, my draw function and two from libc. The faulty address is not null. But the segfault happens after the return where all local variables are no longer in scope, and the addresses of the widget and the cairo context are valid. On 11/29/16 00:44, Alfonso Arbona Gimeno wrote: > Hi, > > Why don't you link against the debug version of the library so that it > shows you the complete stack? > It will give you some extra clues on why the segfault is happening. > > Regards, > Alfonso Arbona > > On November 29, 2016 6:17:05 AM GMT+09:00, zahlenm...@gmx.de wrote: > > For a custom widget I have a draw function. I do some drawing there and > when I am finished I return FALSE to let the parent draw. Immediately > after the return statement I get a segfault. gdb's backtrace only shows > my draw function and an address I cannot associate to any object. > Are there some general tricks how to debug such errors? > > Kind regards > > > gtk-app-devel-list mailing list > gtk-app-devel-list@gnome.org > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list > ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Debugging propagated events
For a custom widget I have a draw function. I do some drawing there and when I am finished I return FALSE to let the parent draw. Immediately after the return statement I get a segfault. gdb's backtrace only shows my draw function and an address I cannot associate to any object. Are there some general tricks how to debug such errors? Kind regards ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list