builtin/config: work around an unsized array forward declaration

As reported here[0], Microsoft Visual Studio 2017.2 and "gcc -pedantic"
don't understand the forward declaration of an unsized static array.
They insist on an array size:

d:\git\src\builtin\config.c(70,46): error C2133: 'builtin_config_options': unknown size

The thread [1] explains that this is due to the single-pass nature of
old compilers.

To work around this error, introduce the forward-declared function
usage_builtin_config() instead that uses the array
builtin_config_options only after it has been defined.

Also use this function in all other places where usage_with_options() is
called with the same arguments.

[0]: https://github.com/git-for-windows/git/issues/1735
[1]: https://groups.google.com/forum/#!topic/comp.lang.c.moderated/bmiF2xMz51U

Fixes https://github.com/git-for-windows/git/issues/1735

Reported-By: Karen Huang (via GitHub)
Signed-off-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/config.c b/builtin/config.c
index 69e7270356c5a4da8372201ac80ec0d33e8909c2..704879a70c4db214d7b10232e781968a3f4416f5 100644 (file)
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -67,7 +67,7 @@ static int show_origin;
        { OPTION_CALLBACK, (s), (l), (v), NULL, (h), PARSE_OPT_NOARG | \
        PARSE_OPT_NONEG, option_parse_type, (i) }
 
        { OPTION_CALLBACK, (s), (l), (v), NULL, (h), PARSE_OPT_NOARG | \
        PARSE_OPT_NONEG, option_parse_type, (i) }
 

-static struct option builtin_config_options[];
+static NORETURN void usage_builtin_config(void);

 
 static int option_parse_type(const struct option *opt, const char *arg,
                             int unset)
 
 static int option_parse_type(const struct option *opt, const char *arg,
                             int unset)


@@ -111,8 +111,7 @@ static int option_parse_type(const struct option *opt, const char *arg,
                 * --type=int'.
                 */
                error("only one type at a time.");
                 * --type=int'.
                 */
                error("only one type at a time.");

-               usage_with_options(builtin_config_usage,
-                       builtin_config_options);
+               usage_builtin_config();

        }
        *to_type = new_type;
 
        }
        *to_type = new_type;
 


@@ -157,11 +156,16 @@ static struct option builtin_config_options[] = {
        OPT_END(),
 };
 
        OPT_END(),
 };
 

+static NORETURN void usage_builtin_config(void)
+{
+       usage_with_options(builtin_config_usage, builtin_config_options);
+}
+

 static void check_argc(int argc, int min, int max) {
        if (argc >= min && argc <= max)
                return;
        error("wrong number of arguments");
 static void check_argc(int argc, int min, int max) {
        if (argc >= min && argc <= max)
                return;
        error("wrong number of arguments");

-       usage_with_options(builtin_config_usage, builtin_config_options);
+       usage_builtin_config();

 }
 
 static void show_config_origin(struct strbuf *buf)
 }
 
 static void show_config_origin(struct strbuf *buf)


@@ -596,7 +600,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
        if (use_global_config + use_system_config + use_local_config +
            !!given_config_source.file + !!given_config_source.blob > 1) {
                error("only one config file at a time.");
        if (use_global_config + use_system_config + use_local_config +
            !!given_config_source.file + !!given_config_source.blob > 1) {
                error("only one config file at a time.");

-               usage_with_options(builtin_config_usage, builtin_config_options);
+               usage_builtin_config();

        }
 
        if (use_local_config && nongit)
        }
 
        if (use_local_config && nongit)


@@ -657,12 +661,12 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 
        if ((actions & (ACTION_GET_COLOR|ACTION_GET_COLORBOOL)) && type) {
                error("--get-color and variable type are incoherent");
 
        if ((actions & (ACTION_GET_COLOR|ACTION_GET_COLORBOOL)) && type) {
                error("--get-color and variable type are incoherent");

-               usage_with_options(builtin_config_usage, builtin_config_options);
+               usage_builtin_config();

        }
 
        if (HAS_MULTI_BITS(actions)) {
                error("only one action at a time.");
        }
 
        if (HAS_MULTI_BITS(actions)) {
                error("only one action at a time.");

-               usage_with_options(builtin_config_usage, builtin_config_options);
+               usage_builtin_config();

        }
        if (actions == 0)
                switch (argc) {
        }
        if (actions == 0)
                switch (argc) {


@@ -670,25 +674,24 @@ int cmd_config(int argc, const char **argv, const char *prefix)
                case 2: actions = ACTION_SET; break;
                case 3: actions = ACTION_SET_ALL; break;
                default:
                case 2: actions = ACTION_SET; break;
                case 3: actions = ACTION_SET_ALL; break;
                default:

-                       usage_with_options(builtin_config_usage, builtin_config_options);
+                       usage_builtin_config();

                }
        if (omit_values &&
            !(actions == ACTION_LIST || actions == ACTION_GET_REGEXP)) {
                error("--name-only is only applicable to --list or --get-regexp");
                }
        if (omit_values &&
            !(actions == ACTION_LIST || actions == ACTION_GET_REGEXP)) {
                error("--name-only is only applicable to --list or --get-regexp");

-               usage_with_options(builtin_config_usage, builtin_config_options);
+               usage_builtin_config();

        }
 
        if (show_origin && !(actions &
                (ACTION_GET|ACTION_GET_ALL|ACTION_GET_REGEXP|ACTION_LIST))) {
                error("--show-origin is only applicable to --get, --get-all, "
                          "--get-regexp, and --list.");
        }
 
        if (show_origin && !(actions &
                (ACTION_GET|ACTION_GET_ALL|ACTION_GET_REGEXP|ACTION_LIST))) {
                error("--show-origin is only applicable to --get, --get-all, "
                          "--get-regexp, and --list.");

-               usage_with_options(builtin_config_usage, builtin_config_options);
+               usage_builtin_config();

        }
 
        if (default_value && !(actions & ACTION_GET)) {
                error("--default is only applicable to --get");
        }
 
        if (default_value && !(actions & ACTION_GET)) {
                error("--default is only applicable to --get");

-               usage_with_options(builtin_config_usage,
-                       builtin_config_options);
+               usage_builtin_config();

        }
 
        if (actions & PAGING_ACTIONS)
        }
 
        if (actions & PAGING_ACTIONS)