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parse-options.[ch]: consistently use "enum parse_opt_flags" 

Use the "enum parse_opt_flags" instead of an "int flags" as arguments
to the various functions in parse-options.c.

Even though this is an enum bitfield there's there's a benefit to
doing this when it comes to the wider C ecosystem. E.g. the GNU
debugger (gdb) will helpfully detect and print out meaningful enum
labels in this case. Here's the output before and after when breaking
in "parse_options()" after invoking "git stash show":

Before:

    (gdb) p flags
    $1 = 9

After:

    (gdb) p flags
    $1 = (PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_UNKNOWN)

Of course as noted in[1] there's a limit to this smartness,
i.e. manually setting it with unrelated enum labels won't be
caught. There are some third-party extensions to do more exhaustive
checking[2], perhaps we'll be able to make use of them sooner than
later.

We've also got prior art using this pattern in the codebase. See
e.g. "enum bloom_filter_computed" added in 312cff5207 (bloom: split
'get_bloom_filter()' in two, 2020-09-16) and the "permitted" enum
added in ce910287e7 (add -p: fix checking of user input, 2020-08-17).

1. https://lore.kernel.org/git/87mtnvvj3c.fsf@evledraar.gmail.com/
2. https://github.com/sinelaw/elfs-clang-plugins/blob/master/enums_conversion/README.md

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
maint
Ævar Arnfjörð Bjarmason 2021-10-08 21:07:38 +02:00 committed by Junio C Hamano
parent 3b723f722d
commit 3f9ab7ccde
2 changed files with 12 additions and 7 deletions
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11
parse-options.c
View File

@ -481,7 +481,8 @@ static void parse_options_check(const struct option *opts)

static void parse_options_start_1(struct parse_opt_ctx_t *ctx,
int argc, const char **argv, const char *prefix,
const struct option *options, int flags)
const struct option *options,
enum parse_opt_flags flags)
{
ctx->argc = argc;
ctx->argv = argv;
@ -506,7 +507,8 @@ static void parse_options_start_1(struct parse_opt_ctx_t *ctx,

void parse_options_start(struct parse_opt_ctx_t *ctx,
int argc, const char **argv, const char *prefix,
const struct option *options, int flags)
const struct option *options,
enum parse_opt_flags flags)
{
memset(ctx, 0, sizeof(*ctx));
parse_options_start_1(ctx, argc, argv, prefix, options, flags);
@ -838,8 +840,9 @@ int parse_options_end(struct parse_opt_ctx_t *ctx)
}

int parse_options(int argc, const char **argv, const char *prefix,
const struct option *options, const char * const usagestr[],
int flags)
const struct option *options,
const char * const usagestr[],
enum parse_opt_flags flags)
{
struct parse_opt_ctx_t ctx;
struct option *real_options;

8
parse-options.h
View File

@ -213,7 +213,8 @@ struct option {
*/
int parse_options(int argc, const char **argv, const char *prefix,
const struct option *options,
const char * const usagestr[], int flags);
const char * const usagestr[],
enum parse_opt_flags flags);

NORETURN void usage_with_options(const char * const *usagestr,
const struct option *options);
@ -262,7 +263,7 @@ struct parse_opt_ctx_t {
const char **out;
int argc, cpidx, total;
const char *opt;
int flags;
enum parse_opt_flags flags;
const char *prefix;
const char **alias_groups; /* must be in groups of 3 elements! */
struct option *updated_options;
@ -270,7 +271,8 @@ struct parse_opt_ctx_t {

void parse_options_start(struct parse_opt_ctx_t *ctx,
int argc, const char **argv, const char *prefix,
const struct option *options, int flags);
const struct option *options,
enum parse_opt_flags flags);

int parse_options_step(struct parse_opt_ctx_t *ctx,
const struct option *options,