Re: Can't build FreeBSD-head with CLANG

-- Eir Nym


On 28 August 2012 22:49, Dimitry Andric <dim_at_freebsd.org> wrote:
> On 2012-08-28 18:31, Eir Nym wrote:
>>
>> I can't build FreeBSD (GENERIC & custom kernel) with clang. Build
>> finishes for i386 and fails for amd64 for same kernels
>
>
> What is the error you were getting on amd64?
>
>
i386 never failed, amd64 — always
>
>> I have bsd box with following clang version:
>>>
>>> FreeBSD clang version 3.0 (branches/release_30 142614) 20111021
>>> Target: x86_64-unknown-freebsd10.0
>>> Thread model: posix
>
>
> This is rather old, we went through clang 3.1 some time ago, and
> recently updated it to 3.2.
>
>

I use to be sure I use latest clang
make kernel-toolchain buildkernel ${other_args}

>
>> I try to compile it with /dev/null as make.conf and following src.conf:
>
> ...
>
>> but I constantly get warnings (not long ago they was errors) in kernel
>> like this:
>> /usr/head/src/sys/netgraph/ng_parse.c:1263:14: warning: comparison of
>> unsigned expression < 0 is always false [-Wtautological-compare]
>>                          if (index < 0 || eptr - (s + *off) != len) {
>>                              ~~~~~ ^ ~
>> 1 warning generated.
>>
>> Also I get not initialized warnings and so on.
>
>
> You can safely ignore those.  They are just an incentive for the
> maintainers to fix them eventually.  Those tautological comparison
> warnings specifically are quite harmless: the compiler will optimize the
> unused code away anyhow.

I know about ignorance, but compiler fails at them.