[libcamera-devel] [PATCH] apps: cam: Fix compilation error with clang when libtiff-4 is not found

[Kieran Bingham]

Quoting Laurent Pinchart via libcamera-devel (2022-10-24 11:46:38)
> When libtiff-4 is not found, the private camera_ member of the FileSink
> class is set but never used. This causes a compilation error with clang:
> 
> In file included from ../../src/apps/cam/file_sink.cpp:19:
> ../../src/apps/cam/file_sink.h:39:27: error: private field 'camera_' is not used [-Werror,-Wunused-private-field]
>         const libcamera::Camera *camera_;
> 
> Fix by making the camera_ member field conditional on HAVE_TIFF.

Ugh, this feels like an ugly fix. I hate it when compiler warnings
(which I want to keep enabled) work against us like this.


Any other proposal is probably just a different ugly workaround on an
unused arg so lets fix the build and ...

Acked-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> 
> Fixes: 6404b163bcbb ("cam: file_sink: Add support for DNG output")
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/apps/cam/file_sink.cpp | 8 ++++++--
>  src/apps/cam/file_sink.h   | 2 ++
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/src/apps/cam/file_sink.cpp b/src/apps/cam/file_sink.cpp
> index 9d60c04e1cf4..4dfacc103c54 100644
> --- a/src/apps/cam/file_sink.cpp
> +++ b/src/apps/cam/file_sink.cpp
> @@ -21,10 +21,14 @@
>  
>  using namespace libcamera;
>  
> -FileSink::FileSink(const libcamera::Camera *camera,
> +FileSink::FileSink([[maybe_unused]] const libcamera::Camera *camera,
>                    const std::map<const libcamera::Stream *, std::string> &streamNames,
>                    const std::string &pattern)
> -       : camera_(camera), streamNames_(streamNames), pattern_(pattern)
> +       :
> +#ifdef HAVE_TIFF
> +         camera_(camera),
> +#endif
> +         streamNames_(streamNames), pattern_(pattern)
>  {
>  }
>  
> diff --git a/src/apps/cam/file_sink.h b/src/apps/cam/file_sink.h
> index 9ce8b619f69d..300edf8dc902 100644
> --- a/src/apps/cam/file_sink.h
> +++ b/src/apps/cam/file_sink.h
> @@ -36,7 +36,9 @@ private:
>                          libcamera::FrameBuffer *buffer,
>                          const libcamera::ControlList &metadata);
>  
> +#ifdef HAVE_TIFF
>         const libcamera::Camera *camera_;
> +#endif
>         std::map<const libcamera::Stream *, std::string> streamNames_;
>         std::string pattern_;
>         std::map<libcamera::FrameBuffer *, std::unique_ptr<Image>> mappedBuffers_;
> 
> base-commit: 24f8ef763a60f410963fd8897a16ae077aaeff0d
> -- 
> Regards,
> 
> Laurent Pinchart
>