git/builtin/interpret-trailers.c
Jeff King 66e3309294 parse-options: prefer opt->value to globals in callbacks
We have several parse-options callbacks that ignore their "opt"
parameters entirely. This is a little unusual, as we'd normally put the
result of the parsing into opt->value. In the case of these callbacks,
though, they directly manipulate global variables instead (and in
most cases the caller sets opt->value to NULL in the OPT_CALLBACK
declaration).

The immediate symptom we'd like to deal with is that the unused "opt"
variables trigger -Wunused-parameter. But how to fix that is debatable.
One option is to annotate them with UNUSED. But another is to have the
caller pass in the appropriate variable via opt->value, and use it. That
has the benefit of making the callbacks reusable (in theory at least),
and makes it clear from the OPT_CALLBACK declaration which variables
will be affected (doubly so for the cases in builtin/fast-export.c,
where we do set opt->value, but it is completely ignored!).

The slight downside is that we lose type safety, since they're now
passing through void pointers.

I went with the "just use them" approach here. The loss of type safety
is unfortunate, but that is already an issue with most of the other
callbacks. If we want to try to address that, we should do so more
consistently (and this patch would prepare these callbacks for whatever
we choose to do there).

Note that in the cases in builtin/fast-export.c, we are passing
anonymous enums. We'll have to give them names so that we can declare
the appropriate pointer type within the callbacks.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-05 14:48:17 -07:00

143 lines
3.8 KiB
C

/*
* Builtin "git interpret-trailers"
*
* Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>
*
*/
#include "builtin.h"
#include "gettext.h"
#include "parse-options.h"
#include "string-list.h"
#include "trailer.h"
#include "config.h"
static const char * const git_interpret_trailers_usage[] = {
N_("git interpret-trailers [--in-place] [--trim-empty]\n"
" [(--trailer <token>[(=|:)<value>])...]\n"
" [--parse] [<file>...]"),
NULL
};
static enum trailer_where where;
static enum trailer_if_exists if_exists;
static enum trailer_if_missing if_missing;
static int option_parse_where(const struct option *opt,
const char *arg, int unset)
{
return trailer_set_where(opt->value, arg);
}
static int option_parse_if_exists(const struct option *opt,
const char *arg, int unset)
{
return trailer_set_if_exists(opt->value, arg);
}
static int option_parse_if_missing(const struct option *opt,
const char *arg, int unset)
{
return trailer_set_if_missing(opt->value, arg);
}
static void new_trailers_clear(struct list_head *trailers)
{
struct list_head *pos, *tmp;
struct new_trailer_item *item;
list_for_each_safe(pos, tmp, trailers) {
item = list_entry(pos, struct new_trailer_item, list);
list_del(pos);
free(item);
}
}
static int option_parse_trailer(const struct option *opt,
const char *arg, int unset)
{
struct list_head *trailers = opt->value;
struct new_trailer_item *item;
if (unset) {
new_trailers_clear(trailers);
return 0;
}
if (!arg)
return -1;
item = xmalloc(sizeof(*item));
item->text = arg;
item->where = where;
item->if_exists = if_exists;
item->if_missing = if_missing;
list_add_tail(&item->list, trailers);
return 0;
}
static int parse_opt_parse(const struct option *opt, const char *arg,
int unset)
{
struct process_trailer_options *v = opt->value;
v->only_trailers = 1;
v->only_input = 1;
v->unfold = 1;
BUG_ON_OPT_NEG(unset);
BUG_ON_OPT_ARG(arg);
return 0;
}
int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
{
struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
LIST_HEAD(trailers);
struct option options[] = {
OPT_BOOL(0, "in-place", &opts.in_place, N_("edit files in place")),
OPT_BOOL(0, "trim-empty", &opts.trim_empty, N_("trim empty trailers")),
OPT_CALLBACK(0, "where", &where, N_("action"),
N_("where to place the new trailer"), option_parse_where),
OPT_CALLBACK(0, "if-exists", &if_exists, N_("action"),
N_("action if trailer already exists"), option_parse_if_exists),
OPT_CALLBACK(0, "if-missing", &if_missing, N_("action"),
N_("action if trailer is missing"), option_parse_if_missing),
OPT_BOOL(0, "only-trailers", &opts.only_trailers, N_("output only the trailers")),
OPT_BOOL(0, "only-input", &opts.only_input, N_("do not apply config rules")),
OPT_BOOL(0, "unfold", &opts.unfold, N_("join whitespace-continued values")),
OPT_CALLBACK_F(0, "parse", &opts, NULL, N_("set parsing options"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG, parse_opt_parse),
OPT_BOOL(0, "no-divider", &opts.no_divider, N_("do not treat --- specially")),
OPT_CALLBACK(0, "trailer", &trailers, N_("trailer"),
N_("trailer(s) to add"), option_parse_trailer),
OPT_END()
};
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, options,
git_interpret_trailers_usage, 0);
if (opts.only_input && !list_empty(&trailers))
usage_msg_opt(
_("--trailer with --only-input does not make sense"),
git_interpret_trailers_usage,
options);
if (argc) {
int i;
for (i = 0; i < argc; i++)
process_trailers(argv[i], &opts, &trailers);
} else {
if (opts.in_place)
die(_("no input file given for in-place editing"));
process_trailers(NULL, &opts, &trailers);
}
new_trailers_clear(&trailers);
return 0;
}