msvc: Fix some "unreferenced formal parameter" warnings

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>

src/cc-compat.h

@@ -40,6 +40,12 @@
 # endif
 #endif
 
+#if defined(_MSC_VER)
+#define GIT_UNUSED_ARG(x) ((void)(x)); /* note trailing ; */
+#else
+#define GIT_UNUSED_ARG(x)
+#endif
+
 /*
  * Does our compiler/platform support the C99 <inttypes.h> and
  * <stdint.h> header files. (C99 requires that <inttypes.h>

src/fileops.h

@@ -15,12 +15,15 @@
 #ifdef GIT_WIN32
 GIT_INLINE(int) link(const char *GIT_UNUSED(old), const char *GIT_UNUSED(new))
 {
+	GIT_UNUSED_ARG(old)
+	GIT_UNUSED_ARG(new)
 	errno = ENOSYS;
 	return -1;
 }
 
 GIT_INLINE(int) git__mkdir(const char *path, int GIT_UNUSED(mode))
 {
+	GIT_UNUSED_ARG(mode)
 	return mkdir(path);
 }
 

tests/t0020-dirent.c

@@ -186,6 +186,8 @@ static walk_data empty = {
 
 static int dont_call_me(void *GIT_UNUSED(state), char *GIT_UNUSED(path))
 {
+	GIT_UNUSED_ARG(state)
+	GIT_UNUSED_ARG(path)
 	test_die("dont_call_me: unexpected callback!");
 }