string-list: mark unused callback parameters

String-lists may be used with callbacks for clearing or iteration. These
callbacks need to conform to a particular interface, even though not
every callback needs all of its parameters. Mark the unused ones to make
-Wunused-parameter happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

archive.c

@@ -500,7 +500,7 @@ static void parse_treeish_arg(const char **argv,
 	ar_args->time = archive_time;
 }
 
-static void extra_file_info_clear(void *util, const char *str)
+static void extra_file_info_clear(void *util, const char *str UNUSED)
 {
 	struct extra_file_info *info = util;
 	free(info->base);

builtin/gc.c

@@ -329,7 +329,7 @@ static uint64_t estimate_repack_memory(struct packed_git *pack)
 	return os_cache + heap;
 }
 
-static int keep_one_pack(struct string_list_item *item, void *data)
+static int keep_one_pack(struct string_list_item *item, void *data UNUSED)
 {
 	strvec_pushf(&repack, "--keep-pack=%s", basename(item->string));
 	return 0;

builtin/remote.c

@@ -940,7 +940,7 @@ static int rm(int argc, const char **argv, const char *prefix)
 	return result;
 }
 
-static void clear_push_info(void *util, const char *string)
+static void clear_push_info(void *util, const char *string UNUSED)
 {
 	struct push_info *info = util;
 	free(info->dest);

merge-ort.c

@@ -397,7 +397,7 @@ struct conflicted_submodule_item {
 	int flag;
 };
 
-static void conflicted_submodule_item_free(void *util, const char *str)
+static void conflicted_submodule_item_free(void *util, const char *str UNUSED)
 {
 	struct conflicted_submodule_item *item = util;
 

reflog-walk.c

@@ -55,7 +55,7 @@ static void free_complete_reflog(struct complete_reflogs *array)
 	free(array);
 }
 
-static void complete_reflogs_clear(void *util, const char *str)
+static void complete_reflogs_clear(void *util, const char *str UNUSED)
 {
 	struct complete_reflogs *array = util;
 	free_complete_reflog(array);

string-list.c

@@ -156,7 +156,7 @@ void filter_string_list(struct string_list *list, int free_util,
 	list->nr = dst;
 }
 
-static int item_is_not_empty(struct string_list_item *item, void *unused)
+static int item_is_not_empty(struct string_list_item *item, void *data UNUSED)
 {
 	return *item->string != '\0';
 }

t/helper/test-path-utils.c

@@ -8,7 +8,8 @@
  * GIT_CEILING_DIRECTORIES.  If the path is unusable for some reason,
  * die with an explanation.
  */
-static int normalize_ceiling_entry(struct string_list_item *item, void *unused)
+static int normalize_ceiling_entry(struct string_list_item *item,
+				   void *data UNUSED)
 {
 	char *ceil = item->string;