checkout: split options[] array in three pieces

This is a preparation step for introducing new commands that do parts
of what checkout does. There will be two new commands, one is about
switching branches, detaching HEAD... one about checking out
paths. These share the a subset of command line options. The rest of
command line options are separate.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -1342,15 +1342,31 @@ static int checkout_branch(struct checkout_opts *opts,
 	return switch_branches(opts, new_branch_info);
 }
 
-int cmd_checkout(int argc, const char **argv, const char *prefix)
+static struct option *add_common_options(struct checkout_opts *opts,
+					 struct option *prevopts)
 {
-	struct checkout_opts real_opts;
-	struct checkout_opts *opts = &real_opts;
-	struct branch_info new_branch_info;
-	int dwim_new_local_branch;
-	int dwim_remotes_matched = 0;
 	struct option options[] = {
 		OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
+		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
+		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
+		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
+			   N_("conflict style (merge or diff3)")),
+		OPT_END()
+	};
+	struct option *newopts = parse_options_concat(prevopts, options);
+	free(prevopts);
+	return newopts;
+}
+
+static struct option *add_switch_branch_options(struct checkout_opts *opts,
+						struct option *prevopts)
+{
+	struct option options[] = {
 		OPT_STRING('b', NULL, &opts->new_branch, N_("branch"),
 			   N_("create and checkout a new branch")),
 		OPT_STRING('B', NULL, &opts->new_branch_force, N_("branch"),
@@ -1360,34 +1376,49 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
 		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
+		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
+			   N_("update ignored files (default)"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL(0, "no-guess", &opts->no_dwim_new_local_branch,
+			 N_("second guess 'git checkout <no-such-branch>'")),
+		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
+			 N_("do not check if another worktree is holding the given ref")),
+		OPT_END()
+	};
+	struct option *newopts = parse_options_concat(prevopts, options);
+	free(prevopts);
+	return newopts;
+}
+
+static struct option *add_checkout_path_options(struct checkout_opts *opts,
+						struct option *prevopts)
+{
+	struct option options[] = {
 		OPT_SET_INT_F('2', "ours", &opts->writeout_stage,
 			      N_("checkout our version for unmerged files"),
 			      2, PARSE_OPT_NONEG),
 		OPT_SET_INT_F('3', "theirs", &opts->writeout_stage,
 			      N_("checkout their version for unmerged files"),
 			      3, PARSE_OPT_NONEG),
-		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
-			   PARSE_OPT_NOCOMPLETE),
-		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
-		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
-			   N_("update ignored files (default)"),
-			   PARSE_OPT_NOCOMPLETE),
-		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
-			   N_("conflict style (merge or diff3)")),
 		OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
 		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
 			 N_("do not limit pathspecs to sparse entries only")),
-		OPT_BOOL(0, "no-guess", &opts->no_dwim_new_local_branch,
-			 N_("do not second guess 'git checkout <no-such-branch>'")),
-		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
-			 N_("do not check if another worktree is holding the given ref")),
-		{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
-			    "checkout", "control recursive updating of submodules",
-			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
-		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
 		OPT_BOOL(0, "overlay", &opts->overlay_mode, N_("use overlay mode (default)")),
-		OPT_END(),
+		OPT_END()
 	};
+	struct option *newopts = parse_options_concat(prevopts, options);
+	free(prevopts);
+	return newopts;
+}
+
+int cmd_checkout(int argc, const char **argv, const char *prefix)
+{
+	struct checkout_opts real_opts;
+	struct checkout_opts *opts = &real_opts;
+	struct branch_info new_branch_info;
+	int dwim_remotes_matched = 0;
+	int dwim_new_local_branch;
+	struct option *options = NULL;
 
 	memset(opts, 0, sizeof(*opts));
 	memset(&new_branch_info, 0, sizeof(new_branch_info));
@@ -1401,6 +1432,11 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 
 	opts->track = BRANCH_TRACK_UNSPECIFIED;
 
+	options = parse_options_dup(options);
+	options = add_common_options(opts, options);
+	options = add_switch_branch_options(opts, options);
+	options = add_checkout_path_options(opts, options);
+
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 

parse-options-cb.c

@@ -122,6 +122,23 @@ int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+struct option *parse_options_dup(const struct option *o)
+{
+	struct option *opts;
+	int nr = 0;
+
+	while (o && o->type != OPTION_END) {
+		nr++;
+		o++;
+	}
+
+	ALLOC_ARRAY(opts, nr + 1);
+	memcpy(opts, o - nr, sizeof(*o) * nr);
+	memset(opts + nr, 0, sizeof(*opts));
+	opts[nr].type = OPTION_END;
+	return opts;
+}
+
 struct option *parse_options_concat(struct option *a, struct option *b)
 {
 	struct option *ret;

parse-options.h

@@ -257,6 +257,7 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 
 int parse_options_end(struct parse_opt_ctx_t *ctx);
 
+struct option *parse_options_dup(const struct option *a);
 struct option *parse_options_concat(struct option *a, struct option *b);
 
 /*----- some often used options -----*/