Re: [PATCH] maint: use consistent widths for comparison of file system constants

[Jim Meyering]

On Wed, May 21, 2014 at 6:46 PM, Pádraig Brady <address@hidden> wrote:
> * src/stat.c (human_fstype): Adjust a couple of existing constants
> to be a consistent width so that the src/fs-magic-compare target
> works without reporting false positives.
> * cfg.mk (sc_fs-magic-compare): A new syntax check to enforce this.
> ---
>  cfg.mk     |    9 +++++++++
>  src/stat.c |    4 ++--
>  2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/cfg.mk b/cfg.mk
> index 66aa55d..f930dae 100644
> --- a/cfg.mk
> +++ b/cfg.mk
> @@ -577,6 +577,15 @@ sc_marked_devdiagnostics:
>         halt='found marked developer diagnostic(s)'                     \
>           $(_sc_search_regexp)
>
> +# Ensure we keep hex constants as 4 or 8 bytes for consistency
> +# and so that make src/fs-magic-compare works consistently
> +sc_fs-magic-compare:
> +       @sed -n 's|.*/\* \(0x[0-9A-F]\{1,\}\) .*\*/|\1|p'               \
> +         $(srcdir)/src/stat.c                                          \
> +         | sed 's/^.\{6\}$$/4 &/; s/^.\{10\}$$/8 &/' | grep '^[^48]'   \
> +           && { echo '$(ME): Hex values in src/stat.c should be 4 or 8 
> bytes' \
> +                 1>&2; exit 1; } || :
> +
>  # Override the default Cc: used in generating an announcement.
>  announcement_Cc_ = $(translation_project_), \
>    address@hidden, address@hidden

Nice.  Thanks!
What do you think about using e.g.,

  grep -vE '^0x(....|........)$'

instead of that latter sed invocation?
Then any offending hex string would be printed.