automake: set test delays to am_cv_filesystem_timestamp_resolution.

This patch is from https://bugs.gnu.org/60808.

* configure.ac: Set test delays to
am_cv_filesystem_timestamp_resolution, instead of hardwiring
5sec on DJGPP and 2sec elsewhere. This speeds up test runs
significantly, informally as much 30%.

diff --git a/configure.ac b/configure.ac
index f78ec5153454655303be44d58cb1b1ab4d6628c6..23a9f97f540a64580f24a36b67d59b327b767288 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -177,15 +177,7 @@ result=no
 test "x$am_cv_prog_ln" = xln && result=yes
 AC_MSG_RESULT([$result])
 
-# The amount we should wait after modifying files depends on the platform.
-# On Windows '95, '98 and ME, files modifications have 2-seconds
-# granularity and can be up to 3 seconds in the future w.r.t. the
-# system clock.  When it is important to ensure one file is older
-# than another we wait at least 5 seconds between creations.
-case $build in
-  *-pc-msdosdjgpp) MODIFICATION_DELAY=5;;
-  *)               MODIFICATION_DELAY=2;;
-esac
+MODIFICATION_DELAY=$am_cv_filesystem_timestamp_resolution
 AC_SUBST([MODIFICATION_DELAY])
 
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