[FFmpeg-devel] [PATCH v2 1/2] configure: don't force specific C++ standard library linking

[Timo Rothenpieler]

On 07.09.2023 23:38, Kacper Michajlow wrote:
> On Thu, 7 Sept 2023 at 15:12, Derek Buitenhuis
> <derek.buitenhuis at gmail.com> wrote:
>>
>> On 9/6/2023 6:31 PM, Kacper Michajlow wrote:
>>> What would be a downside of preferring CXX always if it exists?
>>
>> FFmpeg runs in a multitude of environments with a multitude of portability
>> requirements. Needlessly linking a C++ runtime is not OK.
> 
> This does not answer my question. Let me rephrase. Do we know the case
> where using C++ compiler driver rather than C would degrade the
> quality of the resulting build?
> 
> Using C++ driver would indeed append the (correct) runtime library to
> the linker command, but if nothing references any symbols from it it
> would not be linked. It is also why the current way of forcing
> `lstdc++` kinda works, because it is silently ignored when not needed.
> 
> Implementing logic to use C++ only when necessary is possible, but I'm
> not a big fan of such automation. And in practice not sure how well it
> would work, because it would require trying to link twice every
> dependency in configure.
> 
> Also the fact that "FFmpeg runs in a multitude of environment" is
> precisely why I really don't like the current unconditional including
> `-lstdc++`.

Couldn't you just check if stdc++ is in the ldflags/extralibs, and if 
so, remove it, and use g++ to link?