So far, the output binary has been just "validate", which is quite a
very generic name and doesn't match the package name.
Even though I highly doubt that this program will ever be used outside
of NixOS modules, it's nevertheless less confusing to have a consistent
naming.
Signed-off-by: aszlig <aszlig@nix.build>
The only reason why I was using _GNU_SOURCE was because of vasprintf(),
so getting rid of that extension should make the source way more
portable.
When using vsnprintf() with a null pointer for the output buffer and a
size of 0, I wasn't quite sure whether this would be undefined
behaviour, so I looked it up in the C11 standard.
In section 7.21.6.5, it explicitly mentions this case, so we're lucky:
If n is zero, nothing is written, and s may be a null pointer.
Additionally, section 7.21.6.12 writes the following about vsnprintf():
The vsnprintf function does not invoke the va_end macro.
So to be sure to avoid undefined behaviour I subsequently added the
corresponding va_end() calls.
With this, the platforms attribute is now "unix", because the program
should now even run on OS X, even though it usually wouldn't be needed.
Signed-off-by: aszlig <aszlig@nix.build>
I initially didn't use $CC because I thought this would be GCC specific,
but it turns out that Clang actually accepts -std=gnu11.
So using $CC here might not work on compilers other than Clang or GCC,
but at the moment those are the compilers we typically use in nixpkgs,
so even if we'd use some other compiler it *might* even work there.
I've tested this by compiling against clangStdenv with both $CC and
clang hardcoded and it works.
This was reported by @dkudriavtsev on IRC.
Signed-off-by: aszlig <aszlig@nix.build>
Checking the keyboard layout has been a long set of hurdles so far, with
several attempts. Originally, the checking was introduced by @lheckemann
in #23709.
The initial implementation just was trying to check whether the symbols/
directory contained the layout name.
Unfortunately, that wasn't enough and keyboard variants weren't
recognized, so if you set layout to eg. "dvorak" it will fail with an
error (#25526).
So my improvement on that was to use sed to filter rules/base.lst and
match the layout against that. I fucked up twice with this, first
because layout can be a comma-separated list which I didn't account for
and second because I ran into a Nix issue (NixOS/nix#1426).
After fixing this, it still wasn't enough (and this is btw. what
localectl also does), because we were *only* matching rules but not
symbols, so using "eu" as a layout won't work either.
I decided now it's the time to actually use libxkbcommon to try
compiling the keyboard options and see whether it succeeds. This comes
in the form of a helper tool called xkbvalidate.
IMHO this approach is a lot less error-prone and we can be sure that we
don't forget about anything because that's what the X server itself uses
to compile the keymap.
Another advantage of this is that we now validate the full set of XKB
options rather than just the layout.
Tested this against a variety of wrong and correct keyboard
configurations and against the "keymap" NixOS VM tests.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Cc: @lheckemann, @peti, @7c6f434c, @tohl, @vcunat, @lluchs
Fixes: #27597
