Re: [PATCH] diff: "S_IFREG | 0644" to "(S_IFREG | 0644)" to avoid warning

Ævar Arnfjörð Bjarmason wrote:

-	unsigned mode = canon_mode(S_IFREG | 0644);
+	unsigned mode = canon_mode((S_IFREG | 0644));

Just curious:

#define canon_mode(mode) \
        (S_ISREG(mode) ? (S_IFREG | ce_permissions(mode)) : \
        S_ISLNK(mode) ? S_IFLNK : S_ISDIR(mode) ? S_IFDIR : S_IFGITLINK)

#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)

Since S_ISREG et al are macros, typically they would put their
argument in parentheses in the definition.  How are they defined
in NetBSD sys/stat.h?  What is canon_mode(S_IFREG | 0644) being
misinterpreted to mean?