Re: git: 11ace56fa030 - main - contrib/libxo: fix API header files inclusions in C++ source files

On Sun, Sep 07, 2025 at 06:42:17PM +0000, Ka Ho Ng wrote:
> The branch main has been updated by khng:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=11ace56fa030185025936c795d5cf7c57b266835
> 
> commit 11ace56fa030185025936c795d5cf7c57b266835
> Author:     ShengYi Hung <aokblast@FreeBSD.org>
> AuthorDate: 2025-09-07 18:33:01 +0000
> Commit:     Ka Ho Ng <khng@FreeBSD.org>
> CommitDate: 2025-09-07 18:33:01 +0000
> 
>     contrib/libxo: fix API header files inclusions in C++ source files
>     
>     C++ source files need `extern "C"` to disable C++ name mangling.
>     
>     MFC after:      1 week
>     Reviewed by:    aokblast (previous version), phil, imp (previous version)
>     Differential Revision:  https://reviews.freebsd.org/D47930
> ---
>  contrib/libxo/libxo/xo.h         | 8 ++++++++
>  contrib/libxo/libxo/xo_encoder.h | 8 ++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/contrib/libxo/libxo/xo.h b/contrib/libxo/libxo/xo.h
> index 6a61a16c7cae..7f37b469b54e 100644
> --- a/contrib/libxo/libxo/xo.h
> +++ b/contrib/libxo/libxo/xo.h
> @@ -27,6 +27,10 @@
>  #include <stdlib.h>
>  #include <errno.h>
>  
> +#ifdef __cplusplus
> +extern "C" {
> +#endif /* __cplusplus */
> +
>  #ifdef __dead2
>  #define NORETURN __dead2
>  #else
> @@ -699,4 +703,8 @@ xo_retain_clear_all (void);
>  void
>  xo_retain_clear (const char *fmt);
>  
> +#ifdef __cplusplus
> +}
> +#endif /* __cplusplus */
> +
>  #endif /* INCLUDE_XO_H */
> diff --git a/contrib/libxo/libxo/xo_encoder.h b/contrib/libxo/libxo/xo_encoder.h
> index 099248ae13a6..bb57194ab030 100644
> --- a/contrib/libxo/libxo/xo_encoder.h
> +++ b/contrib/libxo/libxo/xo_encoder.h
> @@ -20,6 +20,10 @@
>  
>  #include <string.h>
>  
> +#ifdef __cplusplus
> +extern "C" {
> +#endif /* __cplusplus */
> +
>  /*
>   * Expose libxo's memory allocation functions
>   */
> @@ -167,4 +171,8 @@ xo_encoder_op_name (xo_encoder_op_t op);
>  void
>  xo_failure (xo_handle_t *xop, const char *fmt, ...);
>  
> +#ifdef __cplusplus
> +}
> +#endif /* __cplusplus */
> +
>  #endif /* XO_ENCODER_H */

Would it be better to use __BEGIN_DECLS?  I am not completely sure due to
contrib/, but libxo is FreeBSD-specific enough already.