linker plugin api limitation

[Rafael Espíndola]

>> I don't think it is implemented in BFD ld. The idea is that using
>>
>> $ ld ... --start-lib <objs> --end-lib
>>
>> should be equivalent to
>> $ ar rc foo.a <objs>
>> $ ld ... foo.a
>>
>> ar is normally very fast, but when doing a fully distributed build one
>> would still need to copy <objs> to a node just to create foo.a. Using
>> --start-lib/--end-lib saves that step.
>>
>
> Have you tried the AR equivalent with gold?

I did not, but I am pretty sure what happens: The plugin is never even
asked to look at the member since gold only needs the archive index to
know the member is not used.

The difference with --start-lib/--end-lib is that gold has to use the
plugin to find out the symbols defined by a file to know if it is
needed in the link or not.

Cheers,
Rafael