[OE-core] [PATCH v2 4/5] bitbake.conf: include ASNEEDED in TARGET_LDFLAGS directly

[Andre McCurdy]

On Tue, May 29, 2018 at 7:13 PM, Khem Raj <raj.khem at gmail.com> wrote:
> On Tue, May 29, 2018 at 2:29 PM, Andre McCurdy <armccurdy at gmail.com> wrote:
>> Previously, ASNEEDED was appended to TARGET_LDFLAGS from
>> as-needed.inc via tcmode-default.inc and so may not have been enabled
>> for external toolchain builds or other configurations which over-ride
>> TCMODE (ie builds which do not include tcmode-default.inc).
>>
>> Include ASNEEDED in TARGET_LDFLAGS directly from bitbake.conf to
>> ensure that the optimisation is applied to all builds (and for
>> consistency with the way that TARGET_LINK_HASH_STYLE is handled).
>
> We have to be ensure that external toolchains can either override or support
> --as-needed feature,

External toolchains can easily over-ride ASNEEDED if they need to.

> since we may not be able to control what linker they use
> or version of gnu ld they may deploy.

When was --as-needed first added to gnu ld? Do you know of an external
toolchain which might not support it?

> From internal toolchains pov
> this is a good change, but It would be good if some users of external toolchains
> can chime in.