[Buildroot] [PATCH 1/1] package/erlang-jiffy: needs -fPIC

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

Hello,

On Fri, 1 Jan 2021 11:01:53 +0100
"Yann E. MORIN" <yann.morin.1998@free.fr> wrote:

> The thing with LTO, is that all files should (but in practice: must) be
> compiled with the same set of options; from the gcc man page:
> 
>     It is recommended that you compile all the files participating in
>     the same link with the same options and also specify those options
>     at link time.
> 
> and later:
> 
>     There are some code generation flags preserved by GCC when generating
>     bytecodes, as they need to be used during the final link. Currently,
>     the following options and their settings are taken from the first
>     object file that explicitly specifies them: -fPIC, [...]
> 
> So, if one file is compiled with -fPIC, then this is recorded in the .o
> for that file, which gcc notices later when doing the link, and thus all
> files must be -fPIC.
> 
> This can be a file compiled by the package itself, or it may come from
> an external (staging) static library.

Ah, this is indeed an interesting explanation, which could explain why
adding it just to LDFLAGS solves the problem.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com