Improve make-temp-file performance on local files

For the motivation behind this patch, please see Bug#28023 and:
http://emacshorrors.com/posts/make-temp-name.html
Although, given the recent changes to Tramp, the related security
problem in make-temp-file is already fixed, make-temp-file still has
several unnecessary system calls.  In the typical case on GNU/Linux,
this patch replaces 8 syscalls (symlink, open, close, readlinkat, uname,
getpid, unlink, umask) by 2 (open, close).
* admin/merge-gnulib (GNULIB_MODULES): Add tempname, now
that Emacs is using it directly.
* configure.ac (AUTO_DEPEND): Remove AC_SYS_LONG_FILE_NAMES;
no longer needed.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lisp/files.el (files--make-magic-temp-file): Rename from
make-temp-file.
(make-temp-file): Use make-temp-file-internal for
non-magic file names.
* src/fileio.c: Include tempname.h.
(make_temp_name_tbl, make_temp_name_count)
(make_temp_name_count_initialized_p, make_temp_name): Remove.
(Fmake_temp_file_internal): New function.
(Fmake_temp_name): Use it.
* src/filelock.c (get_boot_time): Use Fmake_temp_file_internal
instead of make_temp_name.

2 files changed, 2 insertions, 3 deletions

diff --git a/admin/CPP-DEFINES b/admin/CPP-DEFINES
index cead305aee1..10b558d1ada 100644
--- a/admin/CPP-DEFINES
+++ b/admin/CPP-DEFINES
@@ -205,7 +205,6 @@ HAVE_LIBXML2
 HAVE_LIBXMU
 HAVE_LOCALTIME_R
 HAVE_LOCAL_SOCKETS
-HAVE_LONG_FILE_NAMES
 HAVE_LONG_LONG_INT
 HAVE_LRAND48
 HAVE_LSTAT
diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index a16d7fa53ea..7eca64305de 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -39,8 +39,8 @@ GNULIB_MODULES='
   manywarnings memrchr minmax mkostemp mktime nstrftime
   pipe2 pselect pthread_sigmask putenv qcopy-acl readlink readlinkat
   sig2str socklen stat-time std-gnu11 stdalign stddef stdio
-  stpcpy strtoimax symlink sys_stat
-  sys_time time time_r time_rz timegm timer-time timespec-add timespec-sub
+  stpcpy strtoimax symlink sys_stat sys_time
+  tempname time time_r time_rz timegm timer-time timespec-add timespec-sub
   update-copyright unlocked-io utimens
   vla warnings
 '