On Wed, Apr 11, 2018 at 10:24:45AM +0900, Junio C Hamano wrote:
> Taylor Blau <me@xxxxxxxxxxxx> writes:
>
> > Attached is the eighth re-roll of my series to add `--type=<type>` as
> > the preferred alternative for `--<type>`.
> >
> > The main changes since v7 concern handling degenerate cases, such as:
> >
> > * git config --type=int --type=bool
> > * git config --type=int --int
> >
> > We have previously had discussion about whether we should (1) retain the
> > error in previous versions when confronted with multiple, conflicting
> > type specifiers, (2) ignore the error, in favor of making --<type> and
> > --type=<type> true synonyms, or (3) some combination of the two.
> >
> > I have thought some more about my argument that it would be favorable to
> > make "--type=int" and "--int" behave in the same way, and I am no
> > longer convinced that my argument makes sense. It's based on the premise
> > that "--type=<type>" must _necessarily_ allow multiple invocations, such
> > as '--type=int --type=bool', and therefore "--int --bool" should be
> > updated to behave the same way.
> >
> > We are not constrained to this behavior, so in v8, I have taught Git the
> > following:
> >
> > 1. Allow multiple non-conflicting types, such as '--int --int',
> > '--type=int --int', and '--int --type=int'.
> >
> > 2. Disallow multiple conflicting types, such as '--int --bool',
> > '--type=int --bool', and '--int --type=bool'.
> >
> > 3. Allow conflicting types following --no-type, such as '--int
> > --no-type --bool', '--type=int --no-type --bool', and '--int
> > --no-type --type=bool'. Note that this does _not_ introduce options
> > such as '--no-int' and whatnot.
> >
> > This is accomplished by a new locally defined macro called
> > OPT_CALLBACK_VALUE, which allows us to reuse option_parse_type() to
> > handle --int as well, by sending it through as opt->defval.
> >
> > I think that the above is the best-of-all-worlds choice, but I am
> > curious to hear everyone else's thoughts. Thanks in advance for your
> > review.
>
> I too am curious. Personally I do not think your "last one wins"
> was necessarily bad--in fact it internally was consistent--I just
> thought that the log message did not justify the choice well. And I
> do not think the semantics defined by this one, "once you choose,
> stick to it, or explicitly clear the previous choice", is bad,
> either.
:-). If nothing else, I like that we retain more, stricter behavior from
previous versions.
> > diff --git a/builtin/config.c b/builtin/config.c
> > index 5c8952a17c..7184c09582 100644
> > --- a/builtin/config.c
> > +++ b/builtin/config.c
> > @@ -61,28 +61,53 @@ static int show_origin;
> > #define TYPE_PATH 4
> > #define TYPE_EXPIRY_DATE 5
> >
> > +#define OPT_CALLBACK_VALUE(s, l, h, f, i) \
> > + { OPTION_CALLBACK, (s), (l), NULL, NULL, (h), PARSE_OPT_NOARG | \
> > + PARSE_OPT_NONEG, (f), (i) }
> > +
> > +static struct option builtin_config_options[];
>
> OK. I am not sure if OPT_CALLBACK_VALUE() needs to take 'f', as you
> always pass the option_parse_type function to it.
That's fair. I left this in as an indication that something like this
_might_ want to make its way into parse-options.h as a general-purpose
utility, but was not yet ready to do so. Thus, I defined it inside
builtin/config.c.
> > static int option_parse_type(const struct option *opt, const char *arg,
> > int unset)
> > {
> > - int *type = opt->value;
> > -
> > if (unset) {
> > - *type = 0;
> > + type = 0;
> > return 0;
> > }
> >
> > - if (!strcmp(arg, "bool"))
> > - *type = TYPE_BOOL;
> > - else if (!strcmp(arg, "int"))
> > - *type = TYPE_INT;
> > - else if (!strcmp(arg, "bool-or-int"))
> > - *type = TYPE_BOOL_OR_INT;
> > - else if (!strcmp(arg, "path"))
> > - *type = TYPE_PATH;
> > - else if (!strcmp(arg, "expiry-date"))
> > - *type = TYPE_EXPIRY_DATE;
> > - else
> > - die(_("unrecognized --type argument, %s"), arg);
> > + /*
> > + * To support '--<type>' style flags, begin with new_type equal to
> > + * opt->defval.
> > + */
> > + int new_type = opt->defval;
> > + if (!new_type) {
> > + if (!strcmp(arg, "bool"))
> > + new_type = TYPE_BOOL;
> > + else if (!strcmp(arg, "int"))
> > + new_type = TYPE_INT;
> > + else if (!strcmp(arg, "bool-or-int"))
> > + new_type = TYPE_BOOL_OR_INT;
> > + else if (!strcmp(arg, "path"))
> > + new_type = TYPE_PATH;
> > + else if (!strcmp(arg, "expiry-date"))
> > + new_type = TYPE_EXPIRY_DATE;
> > + else
> > + die(_("unrecognized --type argument, %s"), arg);
> > + }
> > +
> > + if (type != 0 && type != new_type) {
> > + /*
> > + * Complain when there is a new type not equal to the old type.
> > + * This allows for combinations like '--int --type=int' and
> > + * '--type=int --type=int', but disallows ones like '--type=bool
> > + * --int' and '--type=bool
> > + * --type=int'.
> > + */
> > + error("only one type at a time.");
> > + usage_with_options(builtin_config_usage,
> > + builtin_config_options);
> > + }
> > + type = new_type;
>
> Does this rely on a file-scope global variable (type)?
I don't think it does. I think I had conflated the difference between
opt->value and opt->defval while amending this patch. What do you think of the
following (which removes reaching outside the function for "type")?
diff --git a/builtin/config.c b/builtin/config.c
index 7184c09582..53755ca461 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -61,8 +61,8 @@ static int show_origin;
#define TYPE_PATH 4
#define TYPE_EXPIRY_DATE 5
-#define OPT_CALLBACK_VALUE(s, l, h, f, i) \
- { OPTION_CALLBACK, (s), (l), NULL, NULL, (h), PARSE_OPT_NOARG | \
+#define OPT_CALLBACK_VALUE(s, l, v, h, f, i) \
+ { OPTION_CALLBACK, (s), (l), (v), NULL, (h), PARSE_OPT_NOARG | \
PARSE_OPT_NONEG, (f), (i) }
static struct option builtin_config_options[];
@@ -71,7 +71,7 @@ static int option_parse_type(const struct option *opt, const char *arg,
int unset)
{
if (unset) {
- type = 0;
+ *((int *) opt->value) = 0;
return 0;
}
@@ -95,7 +95,8 @@ static int option_parse_type(const struct option *opt, const char *arg,
die(_("unrecognized --type argument, %s"), arg);
}
- if (type != 0 && type != new_type) {
+ int *to_type = opt->value;
+ if (*to_type && *to_type != new_type) {
/*
* Complain when there is a new type not equal to the old type.
* This allows for combinations like '--int --type=int' and
@@ -107,7 +108,7 @@ static int option_parse_type(const struct option *opt, const char *arg,
usage_with_options(builtin_config_usage,
builtin_config_options);
}
- type = new_type;
+ *to_type = new_type;
return 0;
}
@@ -135,12 +136,12 @@ static struct option builtin_config_options[] = {
OPT_BIT(0, "get-color", &actions, N_("find the color configured: slot [default]"), ACTION_GET_COLOR),
OPT_BIT(0, "get-colorbool", &actions, N_("find the color setting: slot [stdout-is-tty]"), ACTION_GET_COLORBOOL),
OPT_GROUP(N_("Type")),
- OPT_CALLBACK('t', "type", NULL, "", N_("value is given this type"), option_parse_type),
- OPT_CALLBACK_VALUE(0, "bool", N_("value is \"true\" or \"false\""), option_parse_type, TYPE_BOOL),
- OPT_CALLBACK_VALUE(0, "int", N_("value is decimal number"), option_parse_type, TYPE_INT),
- OPT_CALLBACK_VALUE(0, "bool-or-int", N_("value is --bool or --int"), option_parse_type, TYPE_BOOL_OR_INT),
- OPT_CALLBACK_VALUE(0, "path", N_("value is a path (file or directory name)"), option_parse_type, TYPE_PATH),
- OPT_CALLBACK_VALUE(0, "expiry-date", N_("value is an expiry date"), option_parse_type, TYPE_EXPIRY_DATE),
+ OPT_CALLBACK('t', "type", &type, "", N_("value is given this type"), option_parse_type),
+ OPT_CALLBACK_VALUE(0, "bool", &type, N_("value is \"true\" or \"false\""), option_parse_type, TYPE_BOOL),
+ OPT_CALLBACK_VALUE(0, "int", &type, N_("value is decimal number"), option_parse_type, TYPE_INT),
+ OPT_CALLBACK_VALUE(0, "bool-or-int", &type, N_("value is --bool or --int"), option_parse_type, TYPE_BOOL_OR_INT),
+ OPT_CALLBACK_VALUE(0, "path", &type, N_("value is a path (file or directory name)"), option_parse_type, TYPE_PATH),
+ OPT_CALLBACK_VALUE(0, "expiry-date", &type, N_("value is an expiry date"), option_parse_type, TYPE_EXPIRY_DATE),
OPT_GROUP(N_("Other")),
OPT_BOOL('z', "null", &end_null, N_("terminate values with NUL byte")),
OPT_BOOL(0, "name-only", &omit_values, N_("show variable names only")),
Thanks,
Taylor
