#884441 dh-dlang requires neon on armhf

Package:
ldc
Source:
ldc
Description:
LLVM D Compiler
Submitter:
Matthias Klose
Date:
2025-08-17 17:48:15 UTC
Severity:
important
Tags:
#884441#5
Date:
2017-12-15 08:46:55 UTC
From:
To:
the make snippet reads:

        ifeq ($(DEB_HOST_ARCH),armhf)
            DFLAGS += -mattr=-neon
        endif

neon is not required in the armhf baseline, you must not set this flag. The
minimum fpu requirement is vfpv3-d16.
#884441#10
Date:
2017-12-15 12:53:32 UTC
From:
To:
2017-12-15 9:46 GMT+01:00 Matthias Klose <doko@debian.org>:

Well, that's exactly what this flag does - LDC is compiling with NEON
by default, on upstream's and its Debian maintainer's request, but we
don't want stuff to be compiled in Debian with the NEON extensions
enabled. Therefore, we explicitly tell LDC not to do that.
Mind the minus in front of the "neon" in that line ;-)

This code is duplicated in a lot of D packages at the moment, and
works quite well there, so I don't see the issue. Please reopen the
bug report if there really is a problem though, could be that I am not
seeing the issue here.

FWIW, I will upload a package using this today, so we'll see if the
existing build breaks or not (it really shouldn't).

Cheers,
    Matthias
#884441#15
Date:
2017-12-15 14:05:29 UTC
From:
To:
Control: reopen -1
Control: reassign -1 ldc

ok, but then the issue is in ldc, so you should change the default over there,
like it's done by every other compiler in the distro.
#884441#26
Date:
2017-12-15 14:13:57 UTC
From:
To:
2017-12-15 15:05 GMT+01:00 Matthias Klose <doko@debian.org>:

That's fair enough - the default wasn't changed because upstream
didn't want user-compiled code to run slower on their machine, and
Markos, the LDC maintainer, also didn't like this at all.
Therefore, we change this for Debian packaging only now, as some kind
of compromise.

In any case, that's indeed something to be addressed by the LDC
package, so it makes sense to have the issue report there.

Cheers,
    Matthias
#884441#31
Date:
2017-12-15 18:30:38 UTC
From:
To:
I checked this with LDC devs.  They claimed that the neon baseline was
coming from LLVM, and that it's that package which should be fixed to
not default to it.

The baseline CPU could always be set in ldc2.conf if you really want
it fixed in LDC.

That is at least what I understood from the conversation.

Regards
Iain.
#884441#38
Date:
2018-01-04 20:23:32 UTC
From:
To:
Is this something that still has to be addressed in ldc, or was that
already addressed back in 2016 in ldc 1:1.1.0git20161002.78c0d69-3
(and the make snippet in dh-dlang wasn't required at all)?

cu
Adrian
#884441#43
Date:
2018-01-04 20:29:10 UTC
From:
To:
2018-01-04 21:23 GMT+01:00 Adrian Bunk <bunk@debian.org>:

No. This is issue https://github.com/ldc-developers/ldc/issues/1752
which can't/won't be fixed in LDC for now.
Also, it was kind of agreed on in this report to go with the DFLAGS
solution in Debian for now.

Cheers,
    Matthias