parseopt: add OPT_NOOP_NOARG

Add OPT_NOOP_NOARG, a helper macro to define deprecated options in a
standard way.  The help text is taken from the no-op option -r of
git revert.

The callback could be made to emit a (conditional?) warning later.  And
we could also add OPT_NOOP (requiring an argument) etc. as needed.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index acf1760..4b92514 100644 (file)
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -204,6 +204,11 @@ There are some macros to easily define options:
        "auto", set `int_var` to 1 if stdout is a tty or a pager,
        0 otherwise.
 
+`OPT_NOOP_NOARG(short, long)`::
+       Introduce an option that has no effect and takes no arguments.
+       Use it to hide deprecated options that are still to be recognized
+       and ignored silently.
+
 
 The last element of the array must be `OPT_END()`.
 

diff --git a/parse-options-cb.c b/parse-options-cb.c
index 6db0921..0de5fb1 100644 (file)
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -123,3 +123,8 @@ int parse_opt_string_list(const struct option *opt, const char *arg, int unset)
        string_list_append(v, xstrdup(arg));
        return 0;
 }
+
+int parse_opt_noop_cb(const struct option *opt, const char *arg, int unset)
+{
+       return 0;
+}

diff --git a/parse-options.h b/parse-options.h
index 22c0273..2e811dc 100644 (file)
--- a/parse-options.h
+++ b/parse-options.h
@@ -153,6 +153,11 @@ struct option {
        { OPTION_CALLBACK, (s), (l), (v), "when", (h), PARSE_OPT_OPTARG, \
                parse_opt_color_flag_cb, (intptr_t)"always" }
 
+#define OPT_NOOP_NOARG(s, l) \
+       { OPTION_CALLBACK, (s), (l), NULL, NULL, \
+         "no-op (backward compatibility)", \
+         PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, parse_opt_noop_cb }
+
 /* Deprecated synonym */
 #define OPT_BOOLEAN OPT_COUNTUP
 
@@ -216,6 +221,7 @@ extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
 extern int parse_opt_with_commit(const struct option *, const char *, int);
 extern int parse_opt_tertiary(const struct option *, const char *, int);
 extern int parse_opt_string_list(const struct option *, const char *, int);
+extern int parse_opt_noop_cb(const struct option *, const char *, int);
 
 #define OPT__VERBOSE(var, h)  OPT_BOOLEAN('v', "verbose", (var), (h))
 #define OPT__QUIET(var, h)    OPT_BOOLEAN('q', "quiet",   (var), (h))

diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
index 007f39d..a1e4616 100755 (executable)
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@@ -87,7 +87,7 @@ EOF
 test_expect_success 'long options' '
        test-parse-options --boolean --integer 1729 --boolean --string2=321 \
                --verbose --verbose --no-dry-run --abbrev=10 --file fi.le\
-               > output 2> output.err &&
+               --obsolete > output 2> output.err &&
        test ! -s output.err &&
        test_cmp expect output
 '

diff --git a/test-parse-options.c b/test-parse-options.c
index 91a5701..36487c4 100644 (file)
--- a/test-parse-options.c
+++ b/test-parse-options.c
@@ -54,6 +54,7 @@ int main(int argc, const char **argv)
                OPT_STRING(0, "string2", &string, "str", "get another string"),
                OPT_STRING(0, "st", &string, "st", "get another string (pervert ordering)"),
                OPT_STRING('o', NULL, &string, "str", "get another string"),
+               OPT_NOOP_NOARG(0, "obsolete"),
                OPT_SET_PTR(0, "default-string", &string,
                        "set string to default", (unsigned long)"default"),
                OPT_STRING_LIST(0, "list", &list, "str", "add str to list"),