From: Phillip Wood <phillip.wood123@gmail.com>
To: John Cai via GitGitGadget <gitgitgadget@gmail.com>, git@vger.kernel.org
Cc: John Cai <johncai86@gmail.com>, John Cai <jcai@gitlab.com>
Subject: Re: [PATCH 1/2] diff: consolidate diff algorithm option parsing
Date: Mon, 6 Feb 2023 16:20:28 +0000 [thread overview]
Message-ID: <19a1c71c-d913-8118-a228-da72b5771421@dunelm.org.uk> (raw)
In-Reply-To: <f56bd38ac3f80fb3a7e8c92cadaa57d2b0754b9f.1675568781.git.gitgitgadget@gmail.com>
Hi John
On 05/02/2023 03:46, John Cai via GitGitGadget wrote:
> From: John Cai <jcai@gitlab.com>
>
> The diff option parsing for --minimal, --patience, --histgoram can all
> be consolidated into one function. This is a preparatory step for the
> subsequent commit which teaches diff to keep track of whether or not a
> diff algorithm has been set via the command line.
>
> While we're at it, the logic that sets the diff algorithm in
> diff_opt_diff_algorithm() can be refactored into a helper that will
> allow multiple callsites to set the diff algorithm.
You say "while we're at it" but isn't it a wholly necessary change for
what you want to do?
This patch basically looks good, I've left a couple of comments below,
thanks for separating it out as a preparatory step
> Signed-off-by: John Cai <johncai86@gmail.com>
> ---
> diff.c | 87 ++++++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 54 insertions(+), 33 deletions(-)
>
> diff --git a/diff.c b/diff.c
> index 329eebf16a0..a8a31c81fe7 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -3437,6 +3437,22 @@ static int diff_filepair_is_phoney(struct diff_filespec *one,
> return !DIFF_FILE_VALID(one) && !DIFF_FILE_VALID(two);
> }
>
> +static int set_diff_algorithm(struct diff_options *opts,
> + const char *alg)
> +{
> + long value = parse_algorithm_value(alg);
> +
> + if (value < 0)
> + return 1;
> +
> + /* clear out previous settings */
> + DIFF_XDL_CLR(opts, NEED_MINIMAL);
> + opts->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
> + opts->xdl_opts |= value;
> +
> + return 0;
> +}
> +
> static void builtin_diff(const char *name_a,
> const char *name_b,
> struct diff_filespec *one,
> @@ -5107,17 +5123,40 @@ static int diff_opt_diff_algorithm(const struct option *opt,
> const char *arg, int unset)
> {
> struct diff_options *options = opt->value;
> - long value = parse_algorithm_value(arg);
>
> BUG_ON_OPT_NEG(unset);
> - if (value < 0)
> +
> + if (set_diff_algorithm(options, arg))
> return error(_("option diff-algorithm accepts \"myers\", "
> "\"minimal\", \"patience\" and \"histogram\""));
>
> - /* clear out previous settings */
> - DIFF_XDL_CLR(options, NEED_MINIMAL);
> - options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
> - options->xdl_opts |= value;
> + return 0;
> +}
> +
> +static int diff_opt_diff_algorithm_no_arg(const struct option *opt,
> + const char *arg, int unset)
> +{
> + struct diff_options *options = opt->value;
> +
> + BUG_ON_OPT_NEG(unset);
> + BUG_ON_OPT_ARG(arg);
> +
> + if (!strcmp(opt->long_name, "patience")) {
> + int i;
This is copied from the existing code but as `options->anchors_nr` is a
size_t it is probably worth converting `i` to a size_t here.
> + /*
> + * Both --patience and --anchored use PATIENCE_DIFF
> + * internally, so remove any anchors previously
> + * specified.
> + */
> + for (i = 0; i < options->anchors_nr; i++)
> + free(options->anchors[i]);
> + options->anchors_nr = 0;
> + }
> +
> + if (set_diff_algorithm(options, opt->long_name))
> + return error(_("available diff algorithms include \"myers\", "
> + "\"minimal\", \"patience\" and \"histogram\""));
I think this should be a BUG() as it is a programming error if we reach
this point.
Best Wishes
Phillip
> +
> return 0;
> }
>
> @@ -5242,26 +5281,6 @@ static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
> return 0;
> }
>
> -static int diff_opt_patience(const struct option *opt,
> - const char *arg, int unset)
> -{
> - struct diff_options *options = opt->value;
> - int i;
> -
> - BUG_ON_OPT_NEG(unset);
> - BUG_ON_OPT_ARG(arg);
> - options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
> - /*
> - * Both --patience and --anchored use PATIENCE_DIFF
> - * internally, so remove any anchors previously
> - * specified.
> - */
> - for (i = 0; i < options->anchors_nr; i++)
> - free(options->anchors[i]);
> - options->anchors_nr = 0;
> - return 0;
> -}
> -
> static int diff_opt_ignore_regex(const struct option *opt,
> const char *arg, int unset)
> {
> @@ -5562,9 +5581,10 @@ struct option *add_diff_options(const struct option *opts,
> N_("prevent rename/copy detection if the number of rename/copy targets exceeds given limit")),
>
> OPT_GROUP(N_("Diff algorithm options")),
> - OPT_BIT(0, "minimal", &options->xdl_opts,
> - N_("produce the smallest possible diff"),
> - XDF_NEED_MINIMAL),
> + OPT_CALLBACK_F(0, "minimal", options, NULL,
> + N_("produce the smallest possible diff"),
> + PARSE_OPT_NONEG | PARSE_OPT_NOARG,
> + diff_opt_diff_algorithm_no_arg),
> OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
> N_("ignore whitespace when comparing lines"),
> XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
> @@ -5589,10 +5609,11 @@ struct option *add_diff_options(const struct option *opts,
> OPT_CALLBACK_F(0, "patience", options, NULL,
> N_("generate diff using the \"patience diff\" algorithm"),
> PARSE_OPT_NONEG | PARSE_OPT_NOARG,
> - diff_opt_patience),
> - OPT_BITOP(0, "histogram", &options->xdl_opts,
> - N_("generate diff using the \"histogram diff\" algorithm"),
> - XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
> + diff_opt_diff_algorithm_no_arg),
> + OPT_CALLBACK_F(0, "histogram", options, NULL,
> + N_("generate diff using the \"histogram diff\" algorithm"),
> + PARSE_OPT_NONEG | PARSE_OPT_NOARG,
> + diff_opt_diff_algorithm_no_arg),
> OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
> N_("choose a diff algorithm"),
> PARSE_OPT_NONEG, diff_opt_diff_algorithm),
next prev parent reply other threads:[~2023-02-06 16:20 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-05 3:46 [PATCH 0/2] Teach diff to honor diff algorithms set through git attributes John Cai via GitGitGadget
2023-02-05 3:46 ` [PATCH 1/2] diff: consolidate diff algorithm option parsing John Cai via GitGitGadget
2023-02-06 16:20 ` Phillip Wood [this message]
2023-02-05 3:46 ` [PATCH 2/2] diff: teach diff to read gitattribute diff-algorithm John Cai via GitGitGadget
2023-02-05 17:50 ` Eric Sunshine
2023-02-06 13:10 ` John Cai
2023-02-06 16:27 ` Phillip Wood
2023-02-06 18:14 ` Eric Sunshine
2023-02-06 19:50 ` John Cai
2023-02-09 8:26 ` Elijah Newren
2023-02-09 10:31 ` "bad" diffs (was: [PATCH 2/2] diff: teach diff to read gitattribute diff-algorithm) Ævar Arnfjörð Bjarmason
2023-02-09 16:37 ` [PATCH 2/2] diff: teach diff to read gitattribute diff-algorithm John Cai
2023-02-06 16:39 ` Ævar Arnfjörð Bjarmason
2023-02-06 20:37 ` John Cai
2023-02-07 14:55 ` Phillip Wood
2023-02-07 17:00 ` John Cai
2023-02-09 9:09 ` Elijah Newren
2023-02-09 14:44 ` Phillip Wood
2023-02-10 9:57 ` Elijah Newren
2023-02-11 17:39 ` Phillip Wood
2023-02-11 1:59 ` Jeff King
2023-02-15 2:35 ` Elijah Newren
2023-02-15 4:21 ` Jeff King
2023-02-15 5:20 ` Junio C Hamano
2023-02-15 14:44 ` Phillip Wood
2023-02-15 15:00 ` Jeff King
2023-02-07 17:27 ` Ævar Arnfjörð Bjarmason
2023-02-15 14:47 ` Phillip Wood
2023-02-09 8:44 ` Elijah Newren
2023-02-14 21:16 ` John Cai
2023-02-15 3:41 ` Elijah Newren
2023-02-09 7:50 ` Elijah Newren
2023-02-09 9:41 ` Ævar Arnfjörð Bjarmason
2023-02-11 2:04 ` Jeff King
2023-02-07 17:56 ` Jeff King
2023-02-07 20:18 ` Ævar Arnfjörð Bjarmason
2023-02-07 20:47 ` Junio C Hamano
2023-02-07 21:05 ` Ævar Arnfjörð Bjarmason
2023-02-07 21:28 ` Junio C Hamano
2023-02-07 21:44 ` Ævar Arnfjörð Bjarmason
2023-02-09 16:34 ` John Cai
2023-02-11 1:39 ` Jeff King
2023-02-14 21:40 ` [PATCH v2 0/2] Teach diff to honor diff algorithms set through git attributes John Cai via GitGitGadget
2023-02-14 21:40 ` [PATCH v2 1/2] diff: consolidate diff algorithm option parsing John Cai via GitGitGadget
2023-02-15 2:38 ` Junio C Hamano
2023-02-15 23:34 ` John Cai
2023-02-15 23:42 ` Junio C Hamano
2023-02-16 2:14 ` Jeff King
2023-02-16 2:57 ` Junio C Hamano
2023-02-16 20:34 ` John Cai
2023-02-14 21:40 ` [PATCH v2 2/2] diff: teach diff to read gitattribute diff-algorithm John Cai via GitGitGadget
2023-02-15 2:56 ` Junio C Hamano
2023-02-15 3:20 ` Junio C Hamano
2023-02-16 20:37 ` John Cai
2023-02-17 20:21 ` [PATCH v3 0/2] Teach diff to honor diff algorithms set through git attributes John Cai via GitGitGadget
2023-02-17 20:21 ` [PATCH v3 1/2] diff: consolidate diff algorithm option parsing John Cai via GitGitGadget
2023-02-17 21:27 ` Junio C Hamano
2023-02-18 1:36 ` Elijah Newren
2023-02-17 20:21 ` [PATCH v3 2/2] diff: teach diff to read algorithm from diff driver John Cai via GitGitGadget
2023-02-17 21:50 ` Junio C Hamano
2023-02-18 2:56 ` Elijah Newren
2023-02-20 15:32 ` John Cai
2023-02-20 16:21 ` Elijah Newren
2023-02-20 16:49 ` John Cai
2023-02-20 17:32 ` Elijah Newren
2023-02-20 20:53 ` John Cai
2023-02-22 19:47 ` Jeff King
2023-02-24 17:44 ` John Cai
2023-02-18 1:16 ` [PATCH v3 0/2] Teach diff to honor diff algorithms set through git attributes Elijah Newren
2023-02-20 13:37 ` John Cai
2023-02-20 21:04 ` [PATCH v4 " John Cai via GitGitGadget
2023-02-20 21:04 ` [PATCH v4 1/2] diff: consolidate diff algorithm option parsing John Cai via GitGitGadget
2023-02-20 21:04 ` [PATCH v4 2/2] diff: teach diff to read algorithm from diff driver John Cai via GitGitGadget
2023-02-21 17:34 ` [PATCH v4 0/2] Teach diff to honor diff algorithms set through git attributes Junio C Hamano
2023-02-21 18:05 ` Elijah Newren
2023-02-21 18:51 ` Junio C Hamano
2023-02-21 19:36 ` John Cai
2023-02-21 20:16 ` Elijah Newren
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