Streamline definition of BOOT_TIME_FILE on MS-Windows

* nt/inc/ms-w32.h: Don't define BOOT_TIME_FILE here...
* configure.ac: ...define it here instead, as for the other
systems.

1 files changed, 11 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index 0bc0de1bfac..0236dbd89d8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2643,6 +2643,17 @@ AC_CACHE_CHECK([for old but post-boot file],
          do
            test -f $file && { emacs_cv_boot_time_file=$file; break; }
          done])],
+     # This isn't perfect, as some systems might have the page file in
+     # another place.  Also, I suspect that the time stamp of that
+     # file might also change when Windows enlarges the file due to
+     # insufficient VM.  Still, this seems to be the most reliable
+     # way; the alternative (of using GetSystemTimes) won't work on
+     # laptops that hibernate, because the system clock is stopped
+     # then.  Other possibility would be to run "net statistics
+     # workstation" and parse the output, but that's gross.  So this
+     # should do; if the file is not there, the boot time will be
+     # returned as zero, and filelock.c already handles that.
+     [mingw32], [emacs_cv_boot_time_file=C:/pagefile.sys],
      [*], [emacs_cv_boot_time_file=not-needed])])
 
 AS_CASE([$emacs_cv_boot_time_file],