Re: [PATCH] Create USE_ST_TIMESPEC and turn it on for Darwin

[Junio C Hamano <gitster@pobox.com>]

Brian Gernhardt <benji@silverinsanity.com> writes:

> This also turns it on by default for OS X (Darwin) machines.  Likely
> this is a sane default for other BSD kernels as well, but I don't have
> any to test that assumption on.

Yeah, that was my initial reaction.  Any BSDers?

> diff --git a/git-compat-util.h b/git-compat-util.h
> index 83d8389..1906253 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -393,8 +393,13 @@ void git_qsort(void *base, size_t nmemb, size_t size,
>  #define ST_CTIME_NSEC(st) 0
>  #define ST_MTIME_NSEC(st) 0
>  #else
> +#ifdef USE_ST_TIMESPEC
> +#define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctimespec.tv_nsec))
> +#define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtimespec.tv_nsec))
> +#else
>  #define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
>  #define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
>  #endif
> +#endif

Thanks.

I think this patch moves things in the right direction, but there are
other uses of "st_[cm]tim.tv_nsec" that do not use the ST_[CM]TIME_NSEC
macro.

$ git grep -n -e 'st_[cm]tim\.' --cached -- '*.[ch]'
builtin-fetch-pack.c:810:				|| st.st_mtim.tv_nsec != mtime.nsec
git-compat-util.h:396:#define ST_CTIME_NSEC(st) ((unsigned int)((st).st_ctim.tv_nsec))
git-compat-util.h:397:#define ST_MTIME_NSEC(st) ((unsigned int)((st).st_mtim.tv_nsec))
read-cache.c:207:	if (ce->ce_mtime.nsec != (unsigned int)st->st_mtim.tv_nsec)
read-cache.c:209:	if (trust_ctime && ce->ce_ctime.nsec != (unsigned int)st->st_ctim.tv_nsec)

Probably we should apply the following patch as a fix, and then apply your
enhancement to support st_[cm]timespec systems?

 builtin-fetch-pack.c |    2 +-
 read-cache.c         |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/builtin-fetch-pack.c b/builtin-fetch-pack.c
index 59b0b0a..1d7e023 100644
--- a/builtin-fetch-pack.c
+++ b/builtin-fetch-pack.c
@@ -807,7 +807,7 @@ struct ref *fetch_pack(struct fetch_pack_args *my_args,
 				die("shallow file was removed during fetch");
 		} else if (st.st_mtime != mtime.sec
 #ifdef USE_NSEC
-				|| st.st_mtim.tv_nsec != mtime.nsec
+				|| ST_CTIME_NSEC(st) != mtime.nsec
 #endif
 			  )
 			die("shallow file was changed during fetch");
diff --git a/read-cache.c b/read-cache.c
index b819abb..7f74c8d 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -204,9 +204,9 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
 		changed |= CTIME_CHANGED;
 
 #ifdef USE_NSEC
-	if (ce->ce_mtime.nsec != (unsigned int)st->st_mtim.tv_nsec)
+	if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
 		changed |= MTIME_CHANGED;
-	if (trust_ctime && ce->ce_ctime.nsec != (unsigned int)st->st_ctim.tv_nsec)
+	if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
 		changed |= CTIME_CHANGED;
 #endif