Record ns-timestamps if possible, but do not use it without USE_NSEC
Traditionally, the lack of USE_NSEC meant "do not record nor use the
nanosecond resolution part of the file timestamps". To avoid problems on
filesystems that lose the ns part when the metadata is flushed to the disk
and then later read back in, disabling USE_NSEC has been a good idea in
general.
If you are on a filesystem without such an issue, it does not hurt to read
and store them in the cached stat data in the index entries even if your
git is compiled without USE_NSEC. The index left with such a version of
git can be read by git compiled with USE_NSEC and it can make use of the
nanosecond part to optimize the check to see if the path on the filesystem
hsa been modified since we last looked at.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Makefile b/Makefile
index 27b9569..65b5b8a 100644
--- a/Makefile
+++ b/Makefile
@@ -126,6 +126,9 @@
# randomly break unless your underlying filesystem supports those sub-second
# times (my ext3 doesn't).
#
+# Define NO_NSEC if your "struct stat" does not have "st_ctim.tv_nsec"
+# available. This automatically turns USE_NSEC off.
+#
# Define USE_STDEV below if you want git to care about the underlying device
# change being considered an inode change from the update-index perspective.
#
@@ -737,6 +740,7 @@
NO_MEMMEM = YesPlease
NO_MKDTEMP = YesPlease
NO_STRLCPY = YesPlease
+ NO_NSEC = YesPlease
FREAD_READS_DIRECTORIES = UnfortunatelyYes
INTERNAL_QSORT = UnfortunatelyYes
NEEDS_LIBICONV=YesPlease
@@ -802,6 +806,7 @@
RUNTIME_PREFIX = YesPlease
NO_POSIX_ONLY_PROGRAMS = YesPlease
NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
+ NO_NSEC = YesPlease
COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/regex -Icompat/fnmatch
COMPAT_CFLAGS += -DSNPRINTF_SIZE_CORR=1
COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
@@ -923,6 +928,9 @@
ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
BASIC_CFLAGS += -DNO_ST_BLOCKS_IN_STRUCT_STAT
endif
+ifdef NO_NSEC
+ BASIC_CFLAGS += -DNO_NSEC
+endif
ifdef NO_C99_FORMAT
BASIC_CFLAGS += -DNO_C99_FORMAT
endif
