On Tuesday, 21 March 2017 at 12:31:41 UTC, Robly18 wrote:
Two days of fix attempt laters, here I am. I tried reinstalling
and recompiling SDL from source (since the version from apt-get
was only 2.0.4 and the one Derelict uses seems to be 2.0.5),
and it continues segfaulting at seemingly random places.
Mismatched versions wouldn't be causing a segfault out of the
box. You'd be getting exceptions instead. The only way Derelict
would be the cause of the segfault is if one of the function
pointers is null or one of the function declarations has the
wrong signature.
This isn't related to your problem, but beginning with
DerelictSDL2 2.0, you can specify the version of SDL you'd like
to target, like say 2.0.2:
import derelict.sdl2.sdl;
DerelictSDL2.load(SharedLibVersion(2, 0, 2));
With this, the loader will not throw any exceptions unless the
library version is lower than the one requested. In that case,
there is a potential to see segfaults. For example, you request
at least 2.0.2, the user has 2.0.4, but the binding supports
2.0.5. The 2.0.5 functions will never be loaded, so the function
pointers will be null.
If I ever get around to finishing up the documentation, it will
recommend that you always specify the version you actually want
and do not attempt to call any functions from later versions
unless you have a good reason to do so, but always check for null
first.
I have a function which fills the screen with black using
SDL_FillRect... Then, this same function calls another helper
function... Which segfaults, at SDL_FillRect. That is, the same
function is both working and crashing, when given the exact
same arguments, just in different contexts. And I have no idea
why.
Looking over your code, I see you aren't doing any error
checking. Validate all of your return values and call
SDL_GetError when one of them shows an error (in SDL, that's
either null or a number < 0, depending on the function). Add some
asserts or debug code to check the state of the pointers you're
passing to SDL functions. Given that the program works elsewhere,
I wouldn't expect this to show the issue, but it's still
something you should be doing anyway.
I'll put a link to the repo. It is a slightly more updated
version than the one I've been trying to compile, but it
segfaults anyway. I'm continuing to develop just fine on
Windows, but Derelict on Ubuntu has proven to be a nightmare.
Derelict has worked on Ubuntu for years. It doesn't do anything
special there that it doesn't do on Windows. I'm not able to
check it at the moment, but I have an Ubuntu laptop I'll try your
code on when I get the chance (if you don't resolve the issue
first).
TL;DR: Same code runs on Windows but not Ubuntu, tried to
update and recompile all I could, segmentation faults on
seemingly random places.
http://www.github.com/robly18/sdltest/
