[CMake] Redundant linking when modifying shared libraries

[Robert Maynard]

I agree that we should document this property better.
I recommend looking at the CMake wiki (
https://gitlab.kitware.com/cmake/community/wikis/home ) and thinking
maybe adding a new recipe for `optimizing redundant linking`.

On Thu, Feb 14, 2019 at 3:11 PM Itay Chamiel <itay.chamiel at orcam.com> wrote:
>
> On Thu, Feb 14, 2019 at 8:08 PM Robert Maynard
> <robert.maynard at kitware.com> wrote:
> > By default CMake wants to get a correct build 100% of the time. There
> > is nothing to stop people from having functions defined in a .cxx file
> > with no corresponding header, and using manual forward deceleration is
> > used in a consuming library/executable. By setting
> > `LINK_DEPENDS_NO_SHARED` to `True` you will convert what was a link
> > time error ( renaming the function in the .cxx ) to a run time error.
>
> First of all, thanks for the answer - it's good to understand the
> rationale and to know that in our use case we can safely use this
> setting.
>
> On the question of whether to set this as the default, I understand
> your position and I personally disagree - but do not wish to start a
> debate. However I will say that this simple change has, in a common
> case, reduced my build time from 5 minutes to 15 seconds. At the very
> least could you consider steps to make this setting more known and
> accessible? (No one on Stack Overflow knew about it, and I think
> that's saying something.) Perhaps put it in a FAQ, and/or more
> prominently in the documentation.
>
> Kind regards,
>
> itay
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