File synchronization fixes.

* admin/CPP-DEFINES (BSD_SYSTEM, HAVE_FSYNC): Remove.
* admin/merge-gnulib (GNULIB_MODULES): Add fsync, fdatasync.
* configure.ac (BSD_SYSTEM, BSD_SYSTEM_AHB): Remove; no longer needed.
(fsync): Remove check; now done by gnulib.
* lib/fdatasync.c, lib/fsync.c, m4/fdatasync.m4, m4/fsync.m4:
New files, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib-src/Makefile.in (LIB_FDATASYNC): New macro.
(emacsclient${EXEEXT}): Use it.
* lib-src/emacsclient.c (main): Use fdatasync, not fsync, since we don't
care about metadata.  Keep trying if interrupted.
* lib-src/movemail.c (main, popmail): Don't worry about BSD_SYSTEM, since
fsync is available everywhere (or there is a substitute).  Don't
report an error if fsync returns EINVAL.
* nt/inc/ms-w32.h (fdatasync): New macro, suggested by Eli Zaretskii.
* src/Makefile.in (LIB_FDATASYNC): New macro.
(LIBES): Use it.
* src/conf_post.h (BSD_SYSTEM, BSD_SYSTEM_AHB): Remove; no longer needed.
* src/fileio.c (Fwrite_region, write_region_inhibit_fsync):
Don't worry about HAVE_FSYNC, since a substitute fsync is
available if the system lacks one.
(Fwrite_regin): Retry fsync if interrupted.

Fixes: debbugs:13944

1 files changed, 5 insertions, 31 deletions

diff --git a/configure.ac b/configure.ac
index aed625e44a..0d1f31032a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2872,7 +2872,7 @@ select getpagesize setlocale \
 utimes getrlimit setrlimit shutdown getaddrinfo \
 strsignal setitimer \
 sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \
-gai_strerror mkstemp getline getdelim fsync sync \
+gai_strerror mkstemp getline getdelim sync \
 difftime posix_memalign \
 getpwent endpwent getgrent endgrent \
 touchlock \
@@ -3774,7 +3774,6 @@ esac
 
 dnl Define symbols to identify the version of Unix this is.
 dnl Define all the symbols that apply correctly.
-AH_TEMPLATE(BSD_SYSTEM, [Define if the system is compatible with BSD 4.2.])
 AH_TEMPLATE(DOS_NT, [Define if the system is MS DOS or MS Windows.])
 AH_TEMPLATE(MSDOS, [Define if the system is MS DOS.])
 AH_TEMPLATE(USG, [Define if the system is compatible with System III.])
@@ -3798,30 +3797,12 @@ case $opsys in
     ;;
 
   darwin)
-    dnl BSD4_3 and BSD4_4 are already defined in sys/param.h.
-    AC_DEFINE(BSD_SYSTEM, [])
-    dnl More specific than the above two.  We cannot use __APPLE__ as this
-    dnl may not be defined on non-OSX Darwin, and we cannot define DARWIN
-    dnl here because Panther and lower CoreFoundation.h uses DARWIN to
+    dnl Not __APPLE__, as this may not be defined on non-OSX Darwin.
+    dnl Not DARWIN, because Panther and lower CoreFoundation.h use DARWIN to
     dnl distinguish OS X from pure Darwin.
     AC_DEFINE(DARWIN_OS, [], [Define if the system is Darwin.])
     ;;
 
-  freebsd)
-    dnl Hack to avoid calling AC_PREPROC_IFELSE multiple times.
-    dnl Would not be needed with autoconf >= 2.67, where the
-    dnl preprocessed output is accessible in "conftest.i".
-    AC_DEFINE(BSD_SYSTEM_AHB, 1, [Define if AH_BOTTOM should change BSD_SYSTEM.])
-    ;;
-
-  gnu | netbsd | openbsd )
-    AC_PREPROC_IFELSE([AC_LANG_PROGRAM([[
-#ifndef BSD_SYSTEM
-# error "BSD_SYSTEM not defined"
-#endif
-    ]], [[]])], [], AC_DEFINE(BSD_SYSTEM, 43) )
-    ;;
-
   gnu-linux | gnu-kfreebsd )
     AC_DEFINE(USG, [])
     AC_DEFINE(GNU_LINUX, [], [Define if ths system is compatible with GNU/Linux.])
@@ -4185,15 +4166,8 @@ case "$opsys" in
    LD_SWITCH_SYSTEM_TEMACS="-fno-pie -prebind $libs_nsgui -Xlinker -headerpad -Xlinker $headerpad_extra"
 
    ## This is here because src/Makefile.in did some extra fiddling around
-   ## with LD_SWITCH_SYSTEM.  The cpp logic was:
-   ##   #ifndef LD_SWITCH_SYSTEM
-   ##   #if !defined (__GNUC__) && ((defined (BSD_SYSTEM) && !defined (COFF)))
-   ## Since all the *bsds define LD_SWITCH_SYSTEM, this simplifies to:
-   ## not using gcc, darwin.
-   ## Because this was done in src/Makefile.in, the resulting part of
-   ## LD_SWITCH_SYSTEM was not used in configure (ie, in ac_link).
-   ## It therefore seems cleaner to put this in LD_SWITCH_SYSTEM_TEMACS,
-   ## rather than LD_SWITCH_SYSTEM.
+   ## with LD_SWITCH_SYSTEM.  It seems cleaner to put this in
+   ## LD_SWITCH_SYSTEM_TEMACS instead,
    test "x$LD_SWITCH_SYSTEM" = "x" && test "x$GCC" != "xyes" && \
      LD_SWITCH_SYSTEM_TEMACS="-X $LD_SWITCH_SYSTEM_TEMACS"
    ;;