configure: additional flag checks for fcntl() and socket()

diff --git a/m4/cares-functions.m4 b/m4/cares-functions.m4
index bddd9b4..050a717 100644 (file)
--- a/m4/cares-functions.m4
+++ b/m4/cares-functions.m4
@@ -15,7 +15,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 41
+# serial 42
 
 
 dnl CARES_INCLUDES_ARPA_INET
@@ -699,6 +699,7 @@ AC_DEFUN([CARES_CHECK_FUNC_FCNTL], [
     AC_DEFINE_UNQUOTED(HAVE_FCNTL, 1,
       [Define to 1 if you have the fcntl function.])
     ac_cv_func_fcntl="yes"
+    CARES_CHECK_FUNC_FCNTL_FD_CLOEXEC
     CARES_CHECK_FUNC_FCNTL_O_NONBLOCK
   else
     AC_MSG_RESULT([no])
@@ -707,6 +708,69 @@ AC_DEFUN([CARES_CHECK_FUNC_FCNTL], [
 ])
 
 
+dnl CARES_CHECK_FUNC_FCNTL_FD_CLOEXEC
+dnl -------------------------------------------------
+dnl Verify if fcntl with status flag FD_CLOEXEC is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_FCNTL_FD_CLOEXEC
+dnl will be defined.
+
+AC_DEFUN([CARES_CHECK_FUNC_FCNTL_FD_CLOEXEC], [
+  #
+  tst_compi_fcntl_fd_cloexec="unknown"
+  tst_allow_fcntl_fd_cloexec="unknown"
+  #
+  case $host_os in
+    some_systems)
+      dnl FD_CLOEXEC does not work on these platforms
+      cares_disallow_fcntl_fd_cloexec="yes"
+      ;;
+  esac
+  #
+  if test "$ac_cv_func_fcntl" = "yes"; then
+    AC_MSG_CHECKING([if fcntl FD_CLOEXEC is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $cares_includes_fcntl
+      ]],[[
+        int flags = 0;
+        if(0 != fcntl(0, F_SETFD, flags | FD_CLOEXEC))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_fcntl_fd_cloexec="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_fcntl_fd_cloexec="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_fcntl_fd_cloexec" = "yes"; then
+    AC_MSG_CHECKING([if fcntl FD_CLOEXEC usage allowed])
+    if test "x$cares_disallow_fcntl_fd_cloexec" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fcntl_fd_cloexec="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fcntl_fd_cloexec="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fcntl FD_CLOEXEC might be used])
+  if test "$tst_compi_fcntl_fd_cloexec" = "yes" &&
+     test "$tst_allow_fcntl_fd_cloexec" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FCNTL_FD_CLOEXEC, 1,
+      [Define to 1 if you have a working fcntl FD_CLOEXEC function.])
+    ac_cv_func_fcntl_fd_cloexec="yes"
+  else
+    AC_MSG_RESULT([no])
+    ac_cv_func_fcntl_fd_cloexec="no"
+  fi
+])
+
+
 dnl CARES_CHECK_FUNC_FCNTL_O_NONBLOCK
 dnl -------------------------------------------------
 dnl Verify if fcntl with status flag O_NONBLOCK is
@@ -2858,6 +2922,8 @@ AC_DEFUN([CARES_CHECK_FUNC_SOCKET], [
     AC_DEFINE_UNQUOTED(HAVE_SOCKET, 1,
       [Define to 1 if you have the socket function.])
     ac_cv_func_socket="yes"
+    CARES_CHECK_FUNC_SOCKET_SOCK_CLOEXEC
+    CARES_CHECK_FUNC_SOCKET_SOCK_NONBLOCK
   else
     AC_MSG_RESULT([no])
     ac_cv_func_socket="no"
@@ -2865,6 +2931,140 @@ AC_DEFUN([CARES_CHECK_FUNC_SOCKET], [
 ])
 
 
+dnl CARES_CHECK_FUNC_SOCKET_SOCK_CLOEXEC
+dnl -------------------------------------------------
+dnl Verify if socket with type flag SOCK_CLOEXEC is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_SOCKET_SOCK_CLOEXEC
+dnl will be defined.
+
+AC_DEFUN([CARES_CHECK_FUNC_SOCKET_SOCK_CLOEXEC], [
+  AC_REQUIRE([CARES_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CARES_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CARES_INCLUDES_SOCKET])dnl
+  #
+  tst_compi_socket_sock_cloexec="unknown"
+  tst_allow_socket_sock_cloexec="unknown"
+  #
+  case $host_os in
+    some_systems)
+      dnl socket SOCK_CLOEXEC does not work
+      cares_disallow_socket_sock_cloexec="yes"
+      ;;
+  esac
+  #
+  if test "$ac_cv_func_socket" = "yes"; then
+    AC_MSG_CHECKING([if socket SOCK_CLOEXEC is compilable])
+    AC_COMPILE_IFELSE([
+        $cares_includes_winsock2
+        $cares_includes_sys_socket
+        $cares_includes_socket
+      ]],[[
+        int flags = 0;
+        if(0 != socket(0, flags | SOCK_CLOEXEC, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_socket_sock_cloexec="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_socket_sock_cloexec="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_socket_sock_cloexec" = "yes"; then
+    AC_MSG_CHECKING([if socket SOCK_CLOEXEC usage allowed])
+    if test "x$cares_disallow_socket_sock_cloexec" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_socket_sock_cloexec="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_socket_sock_cloexec="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if socket SOCK_CLOEXEC might be used])
+  if test "$tst_compi_socket_sock_cloexec" = "yes" &&
+     test "$tst_allow_socket_sock_cloexec" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SOCKET_SOCK_CLOEXEC, 1,
+      [Define to 1 if you have a working socket SOCK_CLOEXEC function.])
+    ac_cv_func_socket_sock_cloexec="yes"
+  else
+    AC_MSG_RESULT([no])
+    ac_cv_func_socket_sock_cloexec="no"
+  fi
+])
+
+
+dnl CARES_CHECK_FUNC_SOCKET_SOCK_NONBLOCK
+dnl -------------------------------------------------
+dnl Verify if socket with type flag SOCK_NONBLOCK is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_SOCKET_SOCK_NONBLOCK
+dnl will be defined.
+
+AC_DEFUN([CARES_CHECK_FUNC_SOCKET_SOCK_NONBLOCK], [
+  AC_REQUIRE([CARES_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CARES_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CARES_INCLUDES_SOCKET])dnl
+  #
+  tst_compi_socket_sock_nonblock="unknown"
+  tst_allow_socket_sock_nonblock="unknown"
+  #
+  case $host_os in
+    some_systems)
+      dnl socket SOCK_NONBLOCK does not work
+      cares_disallow_socket_sock_nonblock="yes"
+      ;;
+  esac
+  #
+  if test "$ac_cv_func_socket" = "yes"; then
+    AC_MSG_CHECKING([if socket SOCK_NONBLOCK is compilable])
+    AC_COMPILE_IFELSE([
+        $cares_includes_winsock2
+        $cares_includes_sys_socket
+        $cares_includes_socket
+      ]],[[
+        int flags = 0;
+        if(0 != socket(0, flags | SOCK_NONBLOCK, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_socket_sock_nonblock="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_socket_sock_nonblock="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_socket_sock_nonblock" = "yes"; then
+    AC_MSG_CHECKING([if socket SOCK_NONBLOCK usage allowed])
+    if test "x$cares_disallow_socket_sock_nonblock" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_socket_sock_nonblock="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_socket_sock_nonblock="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if socket SOCK_NONBLOCK might be used])
+  if test "$tst_compi_socket_sock_nonblock" = "yes" &&
+     test "$tst_allow_socket_sock_nonblock" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SOCKET_SOCK_NONBLOCK, 1,
+      [Define to 1 if you have a working socket SOCK_NONBLOCK function.])
+    ac_cv_func_socket_sock_nonblock="yes"
+  else
+    AC_MSG_RESULT([no])
+    ac_cv_func_socket_sock_nonblock="no"
+  fi
+])
+
+
 dnl CARES_CHECK_FUNC_STRCASECMP
 dnl -------------------------------------------------
 dnl Verify if strcasecmp is available, prototyped, and