Re: [PATCH 11/12] selftests/nolibc: Increase coverage of printf format tests

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

On Tue, 3 Feb 2026 19:22:28 +0100
kernel test robot <lkp@intel.com> wrote:

> Hi,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on next-20260202]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/david-laight-linux-gmail-com/tools-nolibc-printf-Move-length-check-to-snprintf-callback/20260203-183919
> base:   next-20260202
> patch link:    https://lore.kernel.org/r/20260203103000.20206-12-david.laight.linux%40gmail.com
> patch subject: [PATCH 11/12] selftests/nolibc: Increase coverage of printf format tests
> config: x86_64-allnoconfig-bpf (https://download.01.org/0day-ci/archive/20260203/202602031944.7j98nfRE-lkp@intel.com/config)
> compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260203/202602031944.7j98nfRE-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602031944.7j98nfRE-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    nolibc-test.c: In function 'test_dirent':
>    nolibc-test.c:784:17: warning: 'readdir_r' is deprecated [-Wdeprecated-declarations]
>      784 |                 ret = readdir_r(dir, &dirent, &result);
>          |                 ^~~
>    In file included from nolibc-test.c:32:
>    /usr/include/dirent.h:185:12: note: declared here
>      185 | extern int readdir_r (DIR *__restrict __dirp,
>          |            ^~~~~~~~~
>    nolibc-test.c: At top level:
> >> nolibc-test.c:1654:1: warning: 'mat' attribute directive ignored [-Wattributes]  
>     1654 | {
>          | ^
> --
> >> nolibc-test.c:1654:1: warning: 'mat' attribute directive ignored [-Wattributes]  
>     1654 | {
>          | ^
> 

Ah, a line I spotted reading the patches that shouldn't have been there.
Changed it expecting an error when I test-built the next 'round'.
For some reason it didn't fail for me (maybe it needs W=1?).
The line is just before expect_vfprintf() and I was looking into why the
tests weren't getting printf format errors and then thinking I could stop
gcc bleating about a missing format attribute - but that doesn't work
because the code is testing invalid formats.

	David