Numerous build regressions

[Friedrich W. H. Kossebau]

Am Sonntag, 25. April 2021, 14:18:29 CEST schrieb Friedrich W. H. Kossebau:
> Am Sonntag, 25. April 2021, 09:56:17 CEST schrieb Ben Cooksley:
> > These failures appear to be due to changes to the export header templates
> > in extra-cmake-modules, and some SSL related functions in KIO.
> 
> Looking into the export header related one. Seems that bluez-qt includes the
> export header also from C code, and the C preprocessor of clang (?) on
> FreeBSD seems to handle a directive like
>     #if defined(__has_cpp_attribute) && __has_cpp_attribute(deprecated)
> not as one like myself would expect it, stopping evaluation before the && ?
> 
> 08:25:02  /usr/home/jenkins/workspace/Administration/Dependency Build
> Extragear kf5-qt5 FreeBSDQt5.15/bluez-qt/build/src/bluezqt_export.h:42:37:
> error: function-like macro '__has_cpp_attribute' is not defined
> 08:25:02  #if defined(__has_cpp_attribute) &&
> __has_cpp_attribute(deprecated)
> 
> Guess that needs some #ifdef __cplusplus protection of some kind. Anyone
> experience with that, while I am learning while writing such code now?

Or rather that GCC has __has_cpp_attribute defined also in C mode, other than 
Clang, and there is no lazy evaluation by the preprocessor?

Still need to research in full detail, but have a first hot-fix testing right 
now locally that does some handling of inclusion of the generated export 
header in C mode, and would push later.

No clue yet whether the other KIO-related build failures also are related to 
the new export header changes, still need to look at that.

Cheers
Friedrich