Re: [PATCH kvmtool] vfio: include libgen.h (for musl compatibility)

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi,

On Sun, Jun 29, 2025 at 10:22:21PM +0200, Thomas Perale wrote:
> Starting GCC14 'implicit-function-declaration' are treated as errors by
> default. When building kvmtool with musl libc, the following error
> occurs due to missing declaration of 'basename':
> 
> vfio/core.c:537:22: error: implicit declaration of function ‘basename’ [-Wimplicit-function-declaration]
>   537 |         group_name = basename(group_path);
>       |                      ^~~~~~~~
> vfio/core.c:537:22: warning: nested extern declaration of ‘basename’ [-Wnested-externs]
> vfio/core.c:537:20: error: assignment to ‘char *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
>   537 |         group_name = basename(group_path);
>       |                    ^
> 
> This patch fixes the issue by including the appropriate header, ensuring
> compatibility with musl and GCC14.
> 
> Signed-off-by: Thomas Perale <thomas.perale@mind.be>
> Signed-off-by: Thomas Perale <perale.thomas@gmail.com>
> ---
>  vfio/core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/vfio/core.c b/vfio/core.c
> index 3ff2c0b..8f88489 100644
> --- a/vfio/core.c
> +++ b/vfio/core.c
> @@ -3,6 +3,7 @@
>  #include "kvm/ioport.h"
>  
>  #include <linux/list.h>
> +#include <libgen.h>

Looking at man 3 basename, there are two version of basename, one is the POSIX
version (this is the one you get by including libgen.h), the other one is the
GNU version.  I don't think kvmtool cares about the differences (group_path is
never '/', and it's not a static string), so if the POSIX version makes
compilation with musl possible:

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

Also checked that this is the only occurence of basename in the sources.

Thanks,
Alex

>  
>  #define VFIO_DEV_DIR		"/dev/vfio"
>  #define VFIO_DEV_NODE		VFIO_DEV_DIR "/vfio"
> -- 
> 2.50.0
> 
>