m4/sys_socket_h.m4

# sys_socket_h.m4
# serial 32
dnl Copyright (C) 2005-2026 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl This file is offered as-is, without any warranty.

dnl From Simon Josefsson.

AC_DEFUN_ONCE([gl_SYS_SOCKET_H],
[
  AC_REQUIRE([gl_SYS_SOCKET_H_DEFAULTS])
  AC_REQUIRE([AC_CANONICAL_HOST])

  GL_GENERATE_SYS_SOCKET_H=false
  AC_CACHE_CHECK([whether <sys/socket.h> is self-contained],
    [gl_cv_header_sys_socket_h_selfcontained],
    [
      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/socket.h>]], [[]])],
        [gl_cv_header_sys_socket_h_selfcontained=yes],
        [gl_cv_header_sys_socket_h_selfcontained=no])
    ])
  if test $gl_cv_header_sys_socket_h_selfcontained = yes; then
    dnl If the shutdown function exists, <sys/socket.h> should define
    dnl SHUT_RD, SHUT_WR, SHUT_RDWR.
    AC_CHECK_FUNCS([shutdown])
    if test $ac_cv_func_shutdown = yes; then
      AC_CACHE_CHECK([whether <sys/socket.h> defines the SHUT_* macros],
        [gl_cv_header_sys_socket_h_shut],
        [
          AC_COMPILE_IFELSE(
            [AC_LANG_PROGRAM([[#include <sys/socket.h>]],
               [[int a[] = { SHUT_RD, SHUT_WR, SHUT_RDWR };]])],
            [gl_cv_header_sys_socket_h_shut=yes],
            [gl_cv_header_sys_socket_h_shut=no])
        ])
      if test $gl_cv_header_sys_socket_h_shut = no; then
        GL_GENERATE_SYS_SOCKET_H=true
      fi
    fi
  fi
  # We need to check for ws2tcpip.h now.
  gl_PREREQ_SYS_H_SOCKET
  gl_PREREQ_SYS_SA_FAMILY
  if test $ac_cv_type_struct_sockaddr_storage = no; then
    HAVE_STRUCT_SOCKADDR_STORAGE=0
  fi
  if test $ac_cv_type_struct_sockaddr_storage != no; then
    AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family],
      [],
      [HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY=0],
      [#include <sys/types.h>
       #ifdef HAVE_SYS_SOCKET_H
       #include <sys/socket.h>
       #endif
       #ifdef HAVE_WS2TCPIP_H
       #include <ws2tcpip.h>
       #endif
      ])
  fi
  if test $HAVE_STRUCT_SOCKADDR_STORAGE = 0 || test $HAVE_SA_FAMILY_T = 0 \
     || test $HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY = 0; then
    GL_GENERATE_SYS_SOCKET_H=true
  fi
  gl_PREREQ_SYS_H_WINSOCK2

  dnl Check for declarations of anything we want to poison if the
  dnl corresponding gnulib module is not in use.
  gl_WARN_ON_USE_PREPARE([[
/* Some systems require prerequisite headers.  */
#include <sys/types.h>
#include <sys/socket.h>
    ]], [socket connect accept bind getpeername getsockname getsockopt
    listen recv send recvfrom sendto setsockopt shutdown accept4])

  AC_REQUIRE([AC_C_RESTRICT])
])

AC_DEFUN([gl_PREREQ_SYS_H_SOCKET],
[
  dnl Check prerequisites of the <sys/socket.h> replacement.
  AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])
  gl_CHECK_NEXT_HEADERS([sys/socket.h])
  if test $ac_cv_header_sys_socket_h = yes; then
    HAVE_SYS_SOCKET_H=1
  else
    HAVE_SYS_SOCKET_H=0
  fi
  AC_SUBST([HAVE_SYS_SOCKET_H])
  gl_PREREQ_SYS_H_WS2TCPIP
])

# Common prerequisites of the <sys/socket.h> replacement and of the
# <sys/select.h> replacement.
# Sets and substitutes HAVE_WINSOCK2_H.
AC_DEFUN([gl_PREREQ_SYS_H_WINSOCK2],
[
  m4_ifdef([gl_UNISTD_H_DEFAULTS], [AC_REQUIRE([gl_UNISTD_H_DEFAULTS])])
  m4_ifdef([gl_SYS_IOCTL_H_DEFAULTS], [AC_REQUIRE([gl_SYS_IOCTL_H_DEFAULTS])])
  AC_CHECK_HEADERS_ONCE([sys/socket.h])
  if test $ac_cv_header_sys_socket_h != yes; then
    dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
    dnl the check for those headers unconditional; yet cygwin reports
    dnl that the headers are present but cannot be compiled (since on
    dnl cygwin, all socket information should come from sys/socket.h).
    AC_CHECK_HEADERS([winsock2.h])
  fi
  if test "$ac_cv_header_winsock2_h" = yes; then
    HAVE_WINSOCK2_H=1
    UNISTD_H_HAVE_WINSOCK2_H=1
    SYS_IOCTL_H_HAVE_WINSOCK2_H=1
  else
    HAVE_WINSOCK2_H=0
  fi
  AC_SUBST([HAVE_WINSOCK2_H])
])

# Common prerequisites of the <sys/socket.h> replacement and of the
# <arpa/inet.h> replacement.
# Sets and substitutes HAVE_WS2TCPIP_H.
AC_DEFUN([gl_PREREQ_SYS_H_WS2TCPIP],
[
  AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])
  if test $ac_cv_header_sys_socket_h = yes; then
    HAVE_WS2TCPIP_H=0
  else
    if test $ac_cv_header_ws2tcpip_h = yes; then
      HAVE_WS2TCPIP_H=1
    else
      HAVE_WS2TCPIP_H=0
    fi
  fi
  AC_SUBST([HAVE_WS2TCPIP_H])
])

# Common prerequisites of the <sys/socket.h> replacement and of the <sys/un.h>
# replacement.
# Sets and substitutes HAVE_SA_FAMILY_T.
AC_DEFUN([gl_PREREQ_SYS_SA_FAMILY],
[
  AC_REQUIRE([gl_CHECK_SOCKET_HEADERS])
  AC_CHECK_TYPES([struct sockaddr_storage, sa_family_t],,,[
  /* sys/types.h is not needed according to POSIX, but the
     sys/socket.h in i386-unknown-freebsd4.10 and
     powerpc-apple-darwin5.5 required it. */
#include <sys/types.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_WS2TCPIP_H
#include <ws2tcpip.h>
#endif
])
  if test $ac_cv_type_sa_family_t = yes; then
    HAVE_SA_FAMILY_T=1
  else
    HAVE_SA_FAMILY_T=0
  fi
  AC_SUBST([HAVE_SA_FAMILY_T])
])

# gl_SYS_SOCKET_MODULE_INDICATOR([modulename])
# sets the shell variable that indicates the presence of the given module
# to a C preprocessor expression that will evaluate to 1.
# This macro invocation must not occur in macros that are AC_REQUIREd.
AC_DEFUN([gl_SYS_SOCKET_MODULE_INDICATOR],
[
  dnl Ensure to expand the default settings once only.
  gl_SYS_SOCKET_H_REQUIRE_DEFAULTS
  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
  dnl Define it also as a C macro, for the benefit of the unit tests.
  gl_MODULE_INDICATOR_FOR_TESTS([$1])
])

# Initializes the default values for AC_SUBSTed shell variables.
# This macro must not be AC_REQUIREd.  It must only be invoked, and only
# outside of macros or in macros that are not AC_REQUIREd.
AC_DEFUN([gl_SYS_SOCKET_H_REQUIRE_DEFAULTS],
[
  m4_defun(GL_MODULE_INDICATOR_PREFIX[_SYS_SOCKET_H_MODULE_INDICATOR_DEFAULTS], [
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SOCKET])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_CONNECT])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ACCEPT])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_BIND])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_GETPEERNAME])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_GETSOCKNAME])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_GETSOCKOPT])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_LISTEN])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_RECV])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SEND])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_RECVFROM])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SENDTO])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SETSOCKOPT])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_SHUTDOWN])
    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_ACCEPT4])
  ])
  m4_require(GL_MODULE_INDICATOR_PREFIX[_SYS_SOCKET_H_MODULE_INDICATOR_DEFAULTS])
  AC_REQUIRE([gl_SYS_SOCKET_H_DEFAULTS])
])

AC_DEFUN([gl_SYS_SOCKET_H_DEFAULTS],
[
  HAVE_STRUCT_SOCKADDR_STORAGE=1; AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE])
  HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY=1;
                        AC_SUBST([HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY])
  HAVE_ACCEPT4=1;       AC_SUBST([HAVE_ACCEPT4])
])