Minor configure/meson cleanup

From 9c8663239ff44a75a615ec5ad81bd8dcad3378a6 Mon Sep 17 00:00:00 2001
From: Thomas Munro <thomas.munro@gmail.com>
Date: Mon, 7 Aug 2023 13:54:54 +1200
Subject: [PATCH 1/2] Don't probe extra libraries for fdatasync.

Commit d2e15083 got rid of the main configure probe and HAVE_FDATASYNC
macro, but we still searched -lrt and -lposix4 for old Solaris systems.
It's in the C library on modern Solaris, as on other supported systems.
---
 configure    | 57 ----------------------------------------------------
 configure.ac |  2 --
 meson.build  |  1 -
 3 files changed, 60 deletions(-)

diff --git a/configure b/configure
index 2e518c8007..9ea188bc9b 100755
--- a/configure
+++ b/configure
@@ -12195,63 +12195,6 @@ if test "$ac_res" != no; then :
 
 fi
 
-# Solaris:
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing fdatasync" >&5
-$as_echo_n "checking for library containing fdatasync... " >&6; }
-if ${ac_cv_search_fdatasync+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  ac_func_search_save_LIBS=$LIBS
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char fdatasync ();
-int
-main ()
-{
-return fdatasync ();
-  ;
-  return 0;
-}
-_ACEOF
-for ac_lib in '' rt posix4; do
-  if test -z "$ac_lib"; then
-    ac_res="none required"
-  else
-    ac_res=-l$ac_lib
-    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
-  fi
-  if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_search_fdatasync=$ac_res
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext
-  if ${ac_cv_search_fdatasync+:} false; then :
-  break
-fi
-done
-if ${ac_cv_search_fdatasync+:} false; then :
-
-else
-  ac_cv_search_fdatasync=no
-fi
-rm conftest.$ac_ext
-LIBS=$ac_func_search_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_fdatasync" >&5
-$as_echo "$ac_cv_search_fdatasync" >&6; }
-ac_res=$ac_cv_search_fdatasync
-if test "$ac_res" != no; then :
-  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
-
-fi
-
 # Cygwin:
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing shmget" >&5
 $as_echo_n "checking for library containing shmget... " >&6; }
diff --git a/configure.ac b/configure.ac
index 3ebe1a796d..e36c1aee5a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1286,8 +1286,6 @@ AC_SEARCH_LIBS(getopt_long, [getopt gnugetopt])
 AC_SEARCH_LIBS(shm_open, rt)
 AC_SEARCH_LIBS(shm_unlink, rt)
 AC_SEARCH_LIBS(clock_gettime, [rt posix4])
-# Solaris:
-AC_SEARCH_LIBS(fdatasync, [rt posix4])
 # Cygwin:
 AC_SEARCH_LIBS(shmget, cygipc)
 # *BSD:
diff --git a/meson.build b/meson.build
index 04ea348852..b7e67264e1 100644
--- a/meson.build
+++ b/meson.build
@@ -2405,7 +2405,6 @@ func_checks = [
   # required. Just checking for dlsym() ought to suffice.
   ['dlsym', {'dependencies': [dl_dep], 'define': false}],
   ['explicit_bzero'],
-  ['fdatasync', {'dependencies': [rt_dep, posix4_dep], 'define': false}], # Solaris
   ['getifaddrs'],
   ['getopt', {'dependencies': [getopt_dep, gnugetopt_dep], 'skip': always_replace_getopt}],
   ['getopt_long', {'dependencies': [getopt_dep, gnugetopt_dep], 'skip': always_replace_getopt_long}],
-- 
2.41.0

From 865bb8a85627c14ec69a8a919486f06cbd45b0fb Mon Sep 17 00:00:00 2001
From: Thomas Munro <thomas.munro@gmail.com>
Date: Mon, 7 Aug 2023 13:56:41 +1200
Subject: [PATCH 2/2] Remove traces of Sun -lposix4.

This was a library on ancient Solaris systems, which was eventually
replaced with -lrt.  Both are obsolete, as the relevant symbols moved
into the C library long ago.
---
 configure    | 2 +-
 configure.ac | 2 +-
 meson.build  | 3 +--
 3 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/configure b/configure
index 9ea188bc9b..3ee4801a35 100755
--- a/configure
+++ b/configure
@@ -12163,7 +12163,7 @@ return clock_gettime ();
   return 0;
 }
 _ACEOF
-for ac_lib in '' rt posix4; do
+for ac_lib in '' rt; do
   if test -z "$ac_lib"; then
     ac_res="none required"
   else
diff --git a/configure.ac b/configure.ac
index e36c1aee5a..314bdb5273 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1285,7 +1285,7 @@ AC_SEARCH_LIBS(socket, [socket ws2_32])
 AC_SEARCH_LIBS(getopt_long, [getopt gnugetopt])
 AC_SEARCH_LIBS(shm_open, rt)
 AC_SEARCH_LIBS(shm_unlink, rt)
-AC_SEARCH_LIBS(clock_gettime, [rt posix4])
+AC_SEARCH_LIBS(clock_gettime, rt)
 # Cygwin:
 AC_SEARCH_LIBS(shmget, cygipc)
 # *BSD:
diff --git a/meson.build b/meson.build
index b7e67264e1..734ad37906 100644
--- a/meson.build
+++ b/meson.build
@@ -2364,7 +2364,6 @@ rt_dep = cc.find_library('rt', required: false)
 dl_dep = cc.find_library('dl', required: false)
 
 util_dep = cc.find_library('util', required: false)
-posix4_dep = cc.find_library('posix4', required: false)
 
 getopt_dep = cc.find_library('getopt', required: false)
 gnugetopt_dep = cc.find_library('gnugetopt', required: false)
@@ -2398,7 +2397,7 @@ endif
 func_checks = [
   ['_configthreadlocale', {'skip': host_system != 'windows'}],
   ['backtrace_symbols', {'dependencies': [execinfo_dep]}],
-  ['clock_gettime', {'dependencies': [rt_dep, posix4_dep], 'define': false}],
+  ['clock_gettime', {'dependencies': [rt_dep], 'define': false}],
   ['copyfile'],
   # gcc/clang's sanitizer helper library provides dlopen but not dlsym, thus
   # when enabling asan the dlopen check doesn't notice that -ldl is actually
-- 
2.41.0