var: mark unused parameters in git_var callbacks

We abstract the set of variables into a table, with a "read" callback to
provide the value of each. Each callback takes a "flag" argument, but
most callbacks don't make use of it.

This flag is a bit odd. It may be set to IDENT_STRICT, which make sense
for ident-based callbacks, but is just confusing for things like
GIT_EDITOR.

At first glance, it seems like this is just a hack to let us directly
stick the generic git_committer_info() and git_author_info() functions
into our table. And we'd be better off to wrap them with local functions
which pass IDENT_STRICT, and have our callbacks take no option at all.

But that doesn't quite work. We pass IDENT_STRICT when the caller asks
for a specific variable, but otherwise do not (so that "git var -l" does
not bail if the committer ident cannot be formed).

So we really do need to pass in the flag to each invocation, even if the
individual callback doesn't care about it. Let's mark the unused ones so
that -Wunused-parameter does not complain. And while we're here, let's
rename them so that it's clear that the flag values we get will be from
the IDENT_* set. That may prevent confusion for future readers of the
code.

Another option would be to define our own local "strict" flag for the
callbacks, and then have wrappers that translate that to IDENT_STRICT
where it matters. But that would be more boilerplate for little gain
(most functions would still ignore the "strict" flag anyway).

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

Author: peff

builtin/var.c

@@ -12,17 +12,17 @@
 
 static const char var_usage[] = "git var (-l | <variable>)";
 
-static const char *editor(int flag)
+static const char *editor(int ident_flag UNUSED)
 {
 	return git_editor();
 }
 
-static const char *sequence_editor(int flag)
+static const char *sequence_editor(int ident_flag UNUSED)
 {
 	return git_sequence_editor();
 }
 
-static const char *pager(int flag)
+static const char *pager(int ident_flag UNUSED)
 {
 	const char *pgm = git_pager(1);
 
@@ -31,7 +31,7 @@ static const char *pager(int flag)
 	return pgm;
 }
 
-static const char *default_branch(int flag)
+static const char *default_branch(int ident_flag UNUSED)
 {
 	return git_default_branch_name(1);
 }