[fpc-devel] EXC_BAD_ACCESS on i386-darwin

[Jonas Maebe]

On 02 Nov 2006, at 14:37, Vincent Snijders wrote:

> I am looking at http://www.freepascal.org/mantis/view.php?id=7723
>
> When the exception is risen the following error is given:
> Program received signal EXC_BAD_ACCESS, Could not access memory.
> Reason: KERN_PROTECTION_FAILURE at address: 0x0000004f
> 0x0019409e in GTKAPIWIDGETCLIENT_DRAWCARET (CLIENT=0x4d38e00,  
> CALLEDBYTIMER=false) at gtkwinapiwindow.pp:730
> 730     gtkwinapiwindow.pp: No such file or directory.
>         in gtkwinapiwindow.pp
>
> What kind of exception is this?

The Mach equivalent of SIGSEGV. You can see the accessed address is  
0x0000004f, which is clearly wrong.

> Line 730 contains:
> if Visible and Blinking and (Timer = 0)
>
> The same variables are used earlier in the procedure, so I don't  
> think the pointer to the complete record is wrong (e.g. nil).

It seems it nevertheless is nil at that point (potentially due to a  
wrong optimization).

Jonas