On Thu, Oct 26, 2017 at 11:13 PM, Junio C Hamano <gitster@xxxxxxxxx> wrote:
> Subject: [PATCH] xdiff: reassign xpparm_t.flags bits
>
> We have packed the bits too tightly in such a way that it is not
> easy to add a new type of whitespace ignoring option, a new type
> of LCS algorithm, or a new type of post-cleanup heuristics.
>
> Reorder bits a bit to give room for these three classes of options
> to grow.
>
> While at it, add a comment in front of the bit definitions to
> clarify in which structure these defined bits may appear.
>
> Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
Reviewed-by: Stefan Beller <sbeller@xxxxxxxxxx>
> ---
> xdiff/xdiff.h | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h
> index b090ad8eac..457cac32d8 100644
> --- a/xdiff/xdiff.h
> +++ b/xdiff/xdiff.h
> @@ -27,22 +27,24 @@
> extern "C" {
> #endif /* #ifdef __cplusplus */
>
> +/* xpparm_t.flags */
> +#define XDF_NEED_MINIMAL (1 << 0)
>
> -#define XDF_NEED_MINIMAL (1 << 1)
The whitespace flags are also stored in xpparm_t, though
these flags can also come in from other sources (e.g. we
just pass it in manually via the interface).
> #define XDF_IGNORE_WHITESPACE (1 << 2)
> #define XDF_IGNORE_WHITESPACE_CHANGE (1 << 3)
> #define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 4)
> #define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE | XDF_IGNORE_WHITESPACE_AT_EOL)
>
> -#define XDF_PATIENCE_DIFF (1 << 5)
> -#define XDF_HISTOGRAM_DIFF (1 << 6)
> +#define XDF_IGNORE_BLANK_LINES (1 << 7)
Is XDF_IGNORE_BLANK_LINES a whitespace option, just
on the lines level instead of the inside one line? I think
it still makes sense to keep it here, slightly separated from
the IGNORE flags.
> +#define XDF_PATIENCE_DIFF (1 << 14)
> +#define XDF_HISTOGRAM_DIFF (1 << 15)
> #define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF)
> #define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK)
>
> -#define XDF_IGNORE_BLANK_LINES (1 << 7)
> -
> -#define XDF_INDENT_HEURISTIC (1 << 8)
> +#define XDF_INDENT_HEURISTIC (1 << 23)
>
> +/* xdemitconf_t.flags */
> #define XDL_EMIT_FUNCNAMES (1 << 0)
> #define XDL_EMIT_FUNCCONTEXT (1 << 2)
This looked like it was carefully crafted to avoid accidental bit overlap
with XDF_NEED_MINIMAL; but these are in different flag fields, this
should be fine.
Thanks,
Stefan
