On 04/01/18 09:18, Christer Solskogen wrote: > On 03.01.2018 16:23, David Brown wrote: >> 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. >> > > No warnings :( > It was worth a shot! > >> 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. >> > > Any tips on which one? The options for gcc was a bit far over my head. > Start with -fsanitize=address -fsanitize=undefined If your code is multi-threading, also try -fsanitize=thread.
