Re: [PATCH v2 1/2] tools/nolibc: Add dirfd()

[David Laight <david.laight.linux@gmail.com>]

On Wed,  7 Oct 2026 14:29:12 +0900
Daniel Palmer <daniel@thingy.jp> wrote:

> This is useful for things like fstatat() on children of a directory
> opened with opendir().
> 
> At the same time use the new internal helper to replace the two places
> that are converting the DIR pointer back into an fd.
> 
> Signed-off-by: Daniel Palmer <daniel@thingy.jp>
> ---
>  tools/include/nolibc/dirent.h | 38 +++++++++++++++++++++++++++--------
>  1 file changed, 30 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/include/nolibc/dirent.h b/tools/include/nolibc/dirent.h
> index 4e02ef25e72d..d282ea8eb5d3 100644
> --- a/tools/include/nolibc/dirent.h
> +++ b/tools/include/nolibc/dirent.h
> @@ -27,6 +27,18 @@ typedef struct {
>  	char dummy[1];
>  } DIR;
>  
> +/* Internal dirfd() that does not set errno */
> +static __attribute__((unused))
> +int __nolibc_dirfd(DIR *dirp)
> +{
> +	intptr_t i = (intptr_t)dirp;
> +
> +	if (i >= 0)
> +		return -1;
> +
> +	return ~i;

Might be better to use a different name for the variable.
The two return statements look the same at a first glance.

David