Issue 17596: Version bindings so that they work for both FreeBSD 11 and 12

[ibuclaw]

Rebase of #2280, with __FreeBSD_version nits.

Haven't yet tested the second commit against gdc/freebsd. But the first passes the testsuite and all unittests.

[dlang-bot]

Thanks for your pull request, @ibuclaw!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✗	17596	blocker	dmd d 2.073.2 and 2.074.1 interim generated dmd segfaults on FreeBSD 12-CURRENT

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + druntime#3271"

[kinke]

I like core.sys.freebsd.config. 👍

The existing symvers, i.e., custom mangle strings would need to be adapted too - either by simply getting rid of them (#3270, but not restricted to version (GNU)) or using the according versions for version (FreeBSD_11) etc. (non-GDC only), in the hopes that the latter makes programs compiled on a FBSD 11 host also run on FBSD 12+.

[ibuclaw]

I like core.sys.freebsd.config. 👍

The existing symvers, i.e., custom mangle strings would need to be adapted too - either by simply getting rid of them (#3270, but not restricted to version (GNU)) or using the according versions for version (FreeBSD_11) etc. (non-GDC only), in the hopes that the latter makes programs compiled on a FBSD 11 host also run on FBSD 12+.

I guess that would be for later, when dmd catches up perhaps.

[kinke]

Nope - as it is here, pre-inode64 functions expecting the old structs are used with LDC too, regardless of whether FreeBSD_12 is defined.

[ibuclaw]

I can deal with that in #3270, so as not to add conflicts between the two. Though you may have so elaborate how you want it to look like, as I guess either the versioned symbol should be explicit for all versions of FreeBSD, or latest should not have any special mangling.

[kinke]

Though you may have so elaborate how you want it to look like

I'm not really suited, the last time I've shortly played with FreeBSD was something like a decade ago. ;) - In case the regular symbols are just aliases, e.g., fstat resolving to fstat@FBSD_1.0 or so when linking on FBSD 11, we probably don't need any custom mangles. IIUC, that would only allow to compile a FBSD 11 version of druntime on FBSD 12 and link against it on FBSD 12 and so enable cross-compiling a FBSD 11 version of a program on more recent versions. Not sure if there's justified interest in something like that.

[ibuclaw]

@kinke - I can't see any problem from here.

#include <sys/mount.h>
int main()
{
  struct statfs fs;
  statfs("42", &fs);
}

$  nm a.out  | grep statfs
         U statfs@@FBSD_1.5

@jmdavis I guess there is zero reason to have pragma(mangle) if this gets merged in then?

[ibuclaw]

dlang/dmd#11982 got merged into master, so now the version 12 path this PR is now enabled on the FreeBSD 12.1 CI pipeline.

[ibuclaw]

@kinke - I've just gone with explicit versions for now. Waiting for CI pipeline results.

[thewilsonator]

Buildkie failure is unrelated.

[jmdavis]

The mistakes here are probably taken from what I did before, but there are a few things that need fixing.

[ibuclaw]

@jmdavis addressed nits.