Re: [PATCH v2] Remove several implicit function declarations

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Feb 08, 2023 at 03:34:16PM +0100, Arjun Shankar wrote:
> During configure, several ioctl checks omit the corresponding include
> and a pwritev2 check uses the wrong feature test macro.
> This commit fixes the same.
> 
> Signed-off-by: Arjun Shankar <arjun@redhat.com>
> ---
> We ran into these when trying to port Fedora to modern C:
> 
> https://fedoraproject.org/wiki/Changes/PortingToModernC
> https://fedoraproject.org/wiki/Toolchain/PortingToModernC
> 
> v2 notes: Removed the changes to unicrash.c;
>           it was already fixed by 5ead2de386d879
> ---
>  m4/package_libcdev.m4 | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
> index bb1ab49c..f987aa4a 100644
> --- a/m4/package_libcdev.m4
> +++ b/m4/package_libcdev.m4
> @@ -117,6 +117,7 @@ AC_DEFUN([AC_HAVE_FIEMAP],
>  #define _GNU_SOURCE
>  #include <linux/fs.h>
>  #include <linux/fiemap.h>
> +#include <sys/ioctl.h>
>  	]], [[
>  struct fiemap *fiemap;
>  ioctl(0, FS_IOC_FIEMAP, (unsigned long)fiemap);
> @@ -153,7 +154,7 @@ AC_DEFUN([AC_HAVE_PWRITEV2],
>    [ AC_MSG_CHECKING([for pwritev2])
>      AC_LINK_IFELSE(
>      [	AC_LANG_PROGRAM([[
> -#define _BSD_SOURCE
> +#define _GNU_SOURCE

Could you update the pwritev2 manpage to document that _GNU_SOURCE is
the feature test macro for pwritev2?

>  #include <sys/uio.h>
>  	]], [[
>  pwritev2(0, 0, 0, 0, 0);
> @@ -454,6 +455,7 @@ AC_DEFUN([AC_HAVE_SG_IO],
>      AC_COMPILE_IFELSE(
>      [	AC_LANG_PROGRAM([[
>  #include <scsi/sg.h>
> +#include <sys/ioctl.h>
>  	]], [[
>  struct sg_io_hdr hdr;
>  ioctl(0, SG_IO, &hdr);
> @@ -471,7 +473,8 @@ AC_DEFUN([AC_HAVE_HDIO_GETGEO],
>    [ AC_MSG_CHECKING([for struct hd_geometry ])
>      AC_COMPILE_IFELSE(
>      [	AC_LANG_PROGRAM([[
> -#include <linux/hdreg.h>,

Gosh, how did that ever work with the trailing comma??

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> +#include <linux/hdreg.h>
> +#include <sys/ioctl.h>
>  	]], [[
>  struct hd_geometry hdr;
>  ioctl(0, HDIO_GETGEO, &hdr);
> -- 
> 2.38.1
>