Program that segfaults with-Ofast

[David Brown]

On 03/01/18 13:28, Christer Solskogen wrote:
> ... but works fine with O2.
> How can I debug that?
> 
> It does not with happen on 6.3.0, but it does with 7.2.0. Or.. say in
> another way: It works in Raspbian, but not in Arch Linux ARM. And it's
> quite easy to make the assumption that the compiler is to blame (it
> might not be!)
> 
> So the question is... How can I debug it?
> Oh, it also segfaults with O3.
> 
> 

First, make sure you are compiling with plenty of warnings (-Wall
-Wextra to start with, but look at the manual for more) to see if there
is anything obvious going on.  Newer versions of gcc have more warnings.

Then try the sanitize options.  That won't stop the program crashing,
but will (hopefully!) stop the program with useful information when the
error occurs.