mark "argv" as unused when we check argc

A few commands don't take any options at all, and confirm this by
checking argc. After that they have no need to look at argv, but we're
still stuck with it by convention. Let's annotate these cases so that
the compiler doesn't complain with -Wunused-parameter.

Note that in scalar and get-tar-commit-id, we're forced to keep argv by
calling convention (the functions must match cmd_main() and builtin
cmd_foo() conventions, respectively). In diff, these are subcommand
modes that we call individually, so we _could_ just drop the argv
parameters entirely. But it's weird to pass argc without argv, and it
implies that the caller knows that the subcommands aren't interested in
further arguments. It's less confusing to just keep them and silence the
compiler warning.

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

builtin/diff.c

@@ -74,7 +74,7 @@ static void stuff_change(struct diff_options *opt,
 }
 
 static int builtin_diff_b_f(struct rev_info *revs,
-			    int argc, const char **argv,
+			    int argc, const char **argv UNUSED,
 			    struct object_array_entry **blob)
 {
 	/* Blob vs file in the working tree*/
@@ -109,7 +109,7 @@ static int builtin_diff_b_f(struct rev_info *revs,
 }
 
 static int builtin_diff_blobs(struct rev_info *revs,
-			      int argc, const char **argv,
+			      int argc, const char **argv UNUSED,
 			      struct object_array_entry **blob)
 {
 	const unsigned mode = canon_mode(S_IFREG | 0644);
@@ -209,7 +209,7 @@ static int builtin_diff_tree(struct rev_info *revs,
 }
 
 static int builtin_diff_combined(struct rev_info *revs,
-				 int argc, const char **argv,
+				 int argc, const char **argv UNUSED,
 				 struct object_array_entry *ent,
 				 int ents, int first_non_parent)
 {

builtin/get-tar-commit-id.c

@@ -14,7 +14,7 @@ static const char builtin_get_tar_commit_id_usage[] =
 #define RECORDSIZE	(512)
 #define HEADERSIZE (2 * RECORDSIZE)
 
-int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
+int cmd_get_tar_commit_id(int argc, const char **argv UNUSED, const char *prefix)
 {
 	char buffer[HEADERSIZE];
 	struct ustar_header *header = (struct ustar_header *)buffer;

scalar.c

@@ -563,7 +563,7 @@ static int cmd_diagnose(int argc, const char **argv)
 	return res;
 }
 
-static int cmd_list(int argc, const char **argv)
+static int cmd_list(int argc, const char **argv UNUSED)
 {
 	if (argc != 1)
 		die(_("`scalar list` does not take arguments"));