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kc3-lang/libevent/configure.ac

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  • Author : fanquake
    Date : 2021-03-28 10:57:11
    Hash : 4c29b01c
    Message : build: remove splice implementation fragments Looks like a `splice` implementation was planned, but has clearly never eventuated (the TODO comment is from ~12 years ago, in 8b5bd77415fb6634fadf08357676926fecf5f032). For now, it's probably better to remove the unused code/correct the docs.

  • configure.ac
  • dnl Copyright 2000-2007 Niels Provos
    dnl Copyright 2007-2012 Niels Provos and Nick Mathewson
    dnl
    dnl See LICENSE for copying information.
    dnl
    dnl Original version Dug Song <dugsong@monkey.org>
    
    AC_INIT(libevent,2.2.0-alpha-dev)
    AC_PREREQ(2.67)
    AC_CONFIG_SRCDIR(event.c)
    
    AC_CONFIG_MACRO_DIR([m4])
    AC_CONFIG_AUX_DIR([build-aux])
    
    dnl Automake setup
    dnl 'foreign' means that GNU package rules are not strictly enforced.
    AM_INIT_AUTOMAKE([1.13 foreign subdir-objects])
    
    dnl make compilation quiet unless V=1 is used
    AM_SILENT_RULES([yes])
    
    AC_CONFIG_HEADERS(config.h  evconfig-private.h:evconfig-private.h.in)
    AC_DEFINE(NUMERIC_VERSION, 0x02020001, [Numeric representation of the version])
    
    dnl Initialize prefix.
    AC_PREFIX_DEFAULT([/usr/local])
    
    dnl Try and get a full POSIX environment on obscure systems
    AC_USE_SYSTEM_EXTENSIONS
    
    dnl the 'build' machine is where we run configure and compile
    dnl the 'host' machine is where the resulting stuff runs.
    AC_CANONICAL_BUILD
    AC_CANONICAL_HOST
    
    dnl Checks for programs.
    AM_PROG_CC_C_O
    AC_PROG_INSTALL
    AC_PROG_LN_S
    AC_PROG_SED
    AC_PROG_GCC_TRADITIONAL
    
    AC_ARG_ENABLE(gcc-warnings,
         AS_HELP_STRING(--disable-gcc-warnings, disable verbose warnings with GCC))
    
    AC_ARG_ENABLE(gcc-hardening,
         AS_HELP_STRING(--enable-gcc-hardening, enable compiler security checks),
    [if test x$enableval = xyes; then
        CFLAGS="$CFLAGS -D_FORTIFY_SOURCE=2 -fstack-protector-all"
        CFLAGS="$CFLAGS -fwrapv -fPIE -Wstack-protector"
        CFLAGS="$CFLAGS --param ssp-buffer-size=1"
    fi])
    
    AC_ARG_ENABLE(thread-support,
         AS_HELP_STRING(--disable-thread-support, disable support for threading),
    	[], [enable_thread_support=yes])
    AC_ARG_ENABLE(malloc-replacement,
         AS_HELP_STRING(--disable-malloc-replacement, disable support for replacing the memory mgt functions),
            [], [enable_malloc_replacement=yes])
    AC_ARG_ENABLE(openssl,
         AS_HELP_STRING(--disable-openssl, disable support for openssl encryption),
            [], [enable_openssl=yes])
    AC_ARG_ENABLE(mbedtls,
         AS_HELP_STRING(--disable-mbedtls, disable support for mbedtls encryption),
            [], [enable_mbedtls=yes])
    AC_ARG_ENABLE(debug-mode,
         AS_HELP_STRING(--disable-debug-mode, disable support for running in debug mode),
            [], [enable_debug_mode=yes])
    AC_ARG_ENABLE([libevent-install],
         AS_HELP_STRING([--disable-libevent-install, disable installation of libevent]),
    	[], [enable_libevent_install=yes])
    AC_ARG_ENABLE([libevent-regress],
         AS_HELP_STRING([--disable-libevent-regress, skip regress in make check]),
    	[], [enable_libevent_regress=yes])
    AC_ARG_ENABLE([samples],
         AS_HELP_STRING([--disable-samples, skip building of sample programs]),
    	[], [enable_samples=yes])
    AC_ARG_ENABLE([function-sections],
         AS_HELP_STRING([--enable-function-sections, make static library allow smaller binaries with --gc-sections]),
    	[], [enable_function_sections=no])
    AC_ARG_ENABLE([verbose-debug],
    		AS_HELP_STRING([--enable-verbose-debug, verbose debug logging]),
    	[], [enable_verbose_debug=no])
    AC_ARG_ENABLE([clock-gettime],
         AS_HELP_STRING(--disable-clock-gettime, do not use clock_gettime even if it is available),
      [], [enable_clock_gettime=yes])
    
    
    LT_PREREQ([2.4.2])
    LT_INIT
    
    AC_SUBST(LIBTOOL_DEPS)
    
    AM_CONDITIONAL([BUILD_SAMPLES], [test "$enable_samples" = "yes"])
    AM_CONDITIONAL([BUILD_REGRESS], [test "$enable_libevent_regress" = "yes"])
    
    dnl Checks for libraries.
    AC_SEARCH_LIBS([inet_ntoa], [nsl])
    AC_SEARCH_LIBS([socket], [socket])
    AC_SEARCH_LIBS([inet_aton], [resolv])
    if test "x$enable_clock_gettime" = "xyes"; then
      AC_SEARCH_LIBS([clock_gettime], [rt])
      AC_CHECK_FUNCS([clock_gettime])
    fi
    AC_SEARCH_LIBS([sendfile], [sendfile])
    
    dnl - check if the macro _WIN32 is defined on this compiler.
    dnl - (this is how we check for a windows compiler)
    AC_MSG_CHECKING(for WIN32)
    AC_COMPILE_IFELSE(
      [AC_LANG_PROGRAM([],
        [
    #ifndef _WIN32
    die horribly
    #endif
        ]
      )],
    	[bwin32=true; AC_MSG_RESULT(yes)],
    	[bwin32=false; AC_MSG_RESULT(no)]
    )
    
    dnl - check if the macro __midipix__ is defined on this compiler.
    dnl - (this is how we check for a midipix version of GCC)
    AC_MSG_CHECKING(for MIDIPIX)
    AC_COMPILE_IFELSE(
      [AC_LANG_PROGRAM([],
        [
    #ifndef __midipix__
    die horribly
    #endif
        ]
      )],
    	[midipix=true; AC_MSG_RESULT(yes)],
    	[midipix=false; AC_MSG_RESULT(no)]
    )
    
    dnl - check if the macro __CYGWIN__ is defined on this compiler.
    dnl - (this is how we check for a cygwin version of GCC)
    AC_MSG_CHECKING(for CYGWIN)
    AC_COMPILE_IFELSE(
      [AC_LANG_PROGRAM([],
        [
    #ifndef __CYGWIN__
    die horribly
    #endif
        ]
      )],
    	[cygwin=true; AC_MSG_RESULT(yes)],
    	[cygwin=false; AC_MSG_RESULT(no)]
    )
    
    AC_CHECK_HEADERS([zlib.h])
    
    if test "x$ac_cv_header_zlib_h" = "xyes"; then
    dnl Determine if we have zlib for regression tests
    dnl Don't put this one in LIBS
    save_LIBS="$LIBS"
    LIBS=""
    ZLIB_LIBS=""
    have_zlib=no
    AC_SEARCH_LIBS([inflateEnd], [z],
    	[have_zlib=yes
    	ZLIB_LIBS="$LIBS"
    	AC_DEFINE(HAVE_LIBZ, 1, [Define if the system has zlib])])
    LIBS="$save_LIBS"
    AC_SUBST(ZLIB_LIBS)
    fi
    AM_CONDITIONAL(ZLIB_REGRESS, [test "$have_zlib" = "yes"])
    
    dnl See if we have openssl.  This doesn't go in LIBS either.
    if test "$bwin32" = true; then
      EV_LIB_WS32=-lws2_32
      EV_LIB_GDI=-lgdi32
    else
      EV_LIB_WS32=
      EV_LIB_GDI=
    fi
    AC_SUBST(EV_LIB_WS32)
    AC_SUBST(EV_LIB_GDI)
    AC_SUBST(OPENSSL_LIBADD)
    
    AC_SYS_LARGEFILE
    
    LIBEVENT_OPENSSL
    LIBEVENT_MBEDTLS
    
    dnl Checks for header files.
    AC_CHECK_HEADERS([ \
      arpa/inet.h \
      fcntl.h \
      ifaddrs.h \
      mach/mach_time.h \
      mach/mach.h \
      netdb.h \
      netinet/in.h \
      netinet/in6.h \
      netinet/tcp.h \
      sys/un.h \
      poll.h \
      port.h \
      stdarg.h \
      stddef.h \
      sys/devpoll.h \
      sys/epoll.h \
      sys/event.h \
      sys/eventfd.h \
      sys/ioctl.h \
      sys/mman.h \
      sys/param.h \
      sys/queue.h \
      sys/resource.h \
      sys/select.h \
      sys/sendfile.h \
      sys/socket.h \
      sys/stat.h \
      sys/time.h \
      sys/timerfd.h \
      sys/uio.h \
      sys/wait.h \
      sys/random.h \
      errno.h \
      afunix.h \
    ])
    
    case "${host_os}" in
        linux*) ;;
        *)
            AC_CHECK_HEADERS(sys/sysctl.h, [], [], [
            #ifdef HAVE_SYS_PARAM_H
            #include <sys/param.h>
            #endif
            ])
    esac
    
    if test "x$ac_cv_header_sys_queue_h" = "xyes"; then
    	AC_MSG_CHECKING(for TAILQ_FOREACH in sys/queue.h)
    	AC_EGREP_CPP(yes,
    [
    #include <sys/queue.h>
    #ifdef TAILQ_FOREACH
     yes
    #endif
    ],	[AC_MSG_RESULT(yes)
    	 AC_DEFINE(HAVE_TAILQFOREACH, 1,
    		[Define if TAILQ_FOREACH is defined in <sys/queue.h>])],
    	AC_MSG_RESULT(no)
    	)
    fi
    
    if test "x$ac_cv_header_sys_time_h" = "xyes"; then
    	AC_MSG_CHECKING(for timeradd in sys/time.h)
    	AC_EGREP_CPP(yes,
    [
    #include <sys/time.h>
    #ifdef timeradd
     yes
    #endif
    ],	[ AC_DEFINE(HAVE_TIMERADD, 1,
    		[Define if timeradd is defined in <sys/time.h>])
    	  AC_MSG_RESULT(yes)] ,AC_MSG_RESULT(no)
    )
    fi
    
    if test "x$ac_cv_header_sys_time_h" = "xyes"; then
    	AC_MSG_CHECKING(for timercmp in sys/time.h)
    	AC_EGREP_CPP(yes,
    [
    #include <sys/time.h>
    #ifdef timercmp
     yes
    #endif
    ],	[ AC_DEFINE(HAVE_TIMERCMP, 1,
    		[Define if timercmp is defined in <sys/time.h>])
    	  AC_MSG_RESULT(yes)] ,AC_MSG_RESULT(no)
    )
    fi
    
    if test "x$ac_cv_header_sys_time_h" = "xyes"; then
    	AC_MSG_CHECKING(for timerclear in sys/time.h)
    	AC_EGREP_CPP(yes,
    [
    #include <sys/time.h>
    #ifdef timerclear
     yes
    #endif
    ],	[ AC_DEFINE(HAVE_TIMERCLEAR, 1,
    		[Define if timerclear is defined in <sys/time.h>])
    	  AC_MSG_RESULT(yes)] ,AC_MSG_RESULT(no)
    )
    fi
    
    if test "x$ac_cv_header_sys_time_h" = "xyes"; then
    	AC_MSG_CHECKING(for timerisset in sys/time.h)
    	AC_EGREP_CPP(yes,
    [
    #include <sys/time.h>
    #ifdef timerisset
     yes
    #endif
    ],	[ AC_DEFINE(HAVE_TIMERISSET, 1,
    		[Define if timerisset is defined in <sys/time.h>])
    	  AC_MSG_RESULT(yes)] ,AC_MSG_RESULT(no)
    )
    fi
    
    if test "x$ac_cv_header_sys_sysctl_h" = "xyes"; then
    	AC_CHECK_DECLS([CTL_KERN, KERN_ARND], [], [],
    	   [[#include <sys/types.h>
    	     #include <sys/sysctl.h>]]
    	)
    fi
    
    AM_CONDITIONAL(BUILD_WIN32, test x$bwin32 = xtrue)
    AM_CONDITIONAL(BUILD_CYGWIN, test x$cygwin = xtrue)
    AM_CONDITIONAL(BUILD_MIDIPIX, test x$midipix = xtrue)
    AM_CONDITIONAL(BUILD_WITH_NO_UNDEFINED, test x$bwin32 = xtrue || test x$cygwin = xtrue || test x$midipix = xtrue)
    
    if test x$bwin32 = xtrue; then
      AC_CHECK_LIB([ws2_32], [main])
    fi
    
    dnl Checks for typedefs, structures, and compiler characteristics.
    AC_C_CONST
    AC_C_INLINE
    AC_HEADER_TIME
    
    dnl Checks for library functions.
    AC_CHECK_FUNCS([ \
      accept4 \
      arc4random \
      arc4random_buf \
      arc4random_addrandom \
      eventfd \
      epoll_create1 \
      fcntl \
      getegid \
      geteuid \
      getifaddrs \
      gettimeofday \
      issetugid \
      mach_absolute_time \
      mmap \
      nanosleep \
      pipe \
      pipe2 \
      putenv \
      sendfile \
      setenv \
      setrlimit \
      sigaction \
      signal \
      strsignal \
      strlcpy \
      strsep \
      strtok_r \
      strtoll \
      sysctl \
      timerfd_create \
      umask \
      unsetenv \
      usleep \
      vasprintf \
      getrandom \
    ])
    
    AS_IF([test x$bwin32 = xtrue],
      AC_CHECK_FUNCS(_gmtime64_s, , [AC_CHECK_FUNCS(_gmtime64)])
    )
    
    AM_CONDITIONAL(STRLCPY_IMPL, [test x"$ac_cv_func_strlcpy" = xno])
    
    m4_define([funcstochk],
      [getnameinfo
      getprotobynumber
      getservbyname
      inet_ntop
      inet_pton]
    )
    
    AS_IF([test x$bwin32 = xtrue],
      [AX_CHECK_DECLS_EX([funcstochk getaddrinfo],
        [#ifdef _WIN32
        #include <winsock2.h>
        #include <ws2tcpip.h>
        #endif])],
      [AC_CHECK_FUNCS(m4_normalize(funcstochk))]
    )
    
    m4_undefine([funcstochk])
    
    dnl check getaddrinfo and gethostbyname_r for non-windows
    AS_IF([test x$bwin32 = xfalse], [
    AC_CACHE_CHECK(
        [for getaddrinfo],
        [libevent_cv_getaddrinfo],
        [AC_LINK_IFELSE(
    	[AC_LANG_PROGRAM(
    	    [[
    		#ifdef HAVE_NETDB_H
    		#include <netdb.h>
    		#endif
    	    ]],
    	    [[
    		getaddrinfo;
    	    ]]
    	)],
    	[libevent_cv_getaddrinfo=yes],
    	[libevent_cv_getaddrinfo=no]
        )]
    )
    if test "$libevent_cv_getaddrinfo" = "yes" ; then
        AC_DEFINE([HAVE_GETADDRINFO], [1], [Do we have getaddrinfo()?])
    else
    
    dnl Check for gethostbyname_r in all its glorious incompatible versions.
    dnl   (This is cut-and-pasted from Tor, which based its logic on
    dnl   Python's configure.in.)
    AH_TEMPLATE(HAVE_GETHOSTBYNAME_R,
      [Define this if you have any gethostbyname_r()])
    
    AC_CHECK_FUNC(gethostbyname_r, [
      AC_MSG_CHECKING([how many arguments gethostbyname_r() wants])
      OLD_CFLAGS=$CFLAGS
      CFLAGS="$CFLAGS $MY_CPPFLAGS $MY_THREAD_CPPFLAGS $MY_CFLAGS"
      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
    #include <netdb.h>
      ], [[
        char *cp1, *cp2;
        struct hostent *h1, *h2;
        int i1, i2;
        (void)gethostbyname_r(cp1,h1,cp2,i1,&h2,&i2);
      ]])],[
        AC_DEFINE(HAVE_GETHOSTBYNAME_R)
        AC_DEFINE(HAVE_GETHOSTBYNAME_R_6_ARG, 1,
         [Define this if gethostbyname_r takes 6 arguments])
        AC_MSG_RESULT(6)
      ], [
        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
    #include <netdb.h>
        ], [
          char *cp1, *cp2;
          struct hostent *h1;
          int i1, i2;
          (void)gethostbyname_r(cp1,h1,cp2,i1,&i2);
        ])], [
          AC_DEFINE(HAVE_GETHOSTBYNAME_R)
          AC_DEFINE(HAVE_GETHOSTBYNAME_R_5_ARG, 1,
            [Define this if gethostbyname_r takes 5 arguments])
          AC_MSG_RESULT(5)
        ], [
          AC_COMPILE_IFELSE([AC_LANG_PROGRAM([
    #include <netdb.h>
         ], [
           char *cp1;
           struct hostent *h1;
           struct hostent_data hd;
           (void) gethostbyname_r(cp1,h1,&hd);
         ])], [
           AC_DEFINE(HAVE_GETHOSTBYNAME_R)
           AC_DEFINE(HAVE_GETHOSTBYNAME_R_3_ARG, 1,
             [Define this if gethostbyname_r takes 3 arguments])
           AC_MSG_RESULT(3)
         ], [
           AC_MSG_RESULT(0)
         ])
      ])
     ])
     CFLAGS=$OLD_CFLAGS
    ])
    
    fi
    ]) dnl end of checking getaddrinfo and gethostbyname_r
    
    AC_MSG_CHECKING(for F_SETFD in fcntl.h)
    AC_EGREP_CPP(yes,
    [
    #define _GNU_SOURCE 1
    #include <fcntl.h>
    #ifdef F_SETFD
    yes
    #endif
    ],	[ AC_DEFINE(HAVE_SETFD, 1,
    	      [Define if F_SETFD is defined in <fcntl.h>])
    	  AC_MSG_RESULT(yes) ], AC_MSG_RESULT(no))
    
    needsignal=no
    haveselect=no
    if test x$bwin32 != xtrue; then
        AC_CHECK_FUNCS(select, [haveselect=yes], )
        if test "x$haveselect" = "xyes" ; then
     	needsignal=yes
        fi
    fi
    AM_CONDITIONAL(SELECT_BACKEND, [test "x$haveselect" = "xyes"])
    
    havepoll=no
    AC_CHECK_FUNCS(poll, [havepoll=yes], )
    if test "x$havepoll" = "xyes" ; then
    	needsignal=yes
    fi
    AM_CONDITIONAL(POLL_BACKEND, [test "x$havepoll" = "xyes"])
    
    havedevpoll=no
    if test "x$ac_cv_header_sys_devpoll_h" = "xyes"; then
    	AC_DEFINE(HAVE_DEVPOLL, 1,
    		    [Define if /dev/poll is available])
    fi
    AM_CONDITIONAL(DEVPOLL_BACKEND, [test "x$ac_cv_header_sys_devpoll_h" = "xyes"])
    
    havekqueue=no
    if test "x$ac_cv_header_sys_event_h" = "xyes"; then
    	AC_CHECK_FUNCS(kqueue, [havekqueue=yes], )
    	if test "x$havekqueue" = "xyes" ; then
    		AC_MSG_CHECKING(for working kqueue)
    		AC_RUN_IFELSE(
          [AC_LANG_PROGRAM([
    #ifdef HAVE_STDLIB_H
    #include <stdlib.h>
    #endif
    #ifdef HAVE_STRING_H
    #include <string.h>
    #endif
    #include <sys/types.h>
    #include <sys/time.h>
    #include <sys/event.h>
    #include <stdio.h>
    #include <unistd.h>
    #include <fcntl.h>
            ], [[
    	int kq;
    	int n;
    	int fd[2];
    	struct kevent ev;
    	struct timespec ts;
    	char buf[80000];
    
    	if (pipe(fd) == -1)
      		return 1;
    	if (fcntl(fd[1], F_SETFL, O_NONBLOCK) == -1)
    		return 1;
    
    	while ((n = write(fd[1], buf, sizeof(buf))) == sizeof(buf))
    		;
    
    	if ((kq = kqueue()) == -1)
    		return 1;
    
    	memset(&ev, 0, sizeof(ev));
    	ev.ident = fd[1];
    	ev.filter = EVFILT_WRITE;
    	ev.flags = EV_ADD | EV_ENABLE;
    	n = kevent(kq, &ev, 1, NULL, 0, NULL);
    	if (n == -1)
    		return 1;
    
    	read(fd[0], buf, sizeof(buf));
    
    	ts.tv_sec = 0;
    	ts.tv_nsec = 0;
    	n = kevent(kq, NULL, 0, &ev, 1, &ts);
    	if (n == -1 || n == 0)
    		return 1;
    
    	return 0;
            ]]
          )],
          [AC_MSG_RESULT(yes)
          AC_DEFINE(HAVE_WORKING_KQUEUE, 1,
            [Define if kqueue works correctly with pipes])
          havekqueue=yes
          ], [AC_MSG_RESULT(no)], [AC_MSG_RESULT(no)]
        )
    	fi
    fi
    AM_CONDITIONAL(KQUEUE_BACKEND, [test "x$havekqueue" = "xyes"])
    
    haveepollsyscall=no
    haveepoll=no
    AC_CHECK_FUNCS(epoll_ctl, [haveepoll=yes], )
    if test "x$haveepoll" = "xyes" ; then
    	AC_DEFINE(HAVE_EPOLL, 1,
    		[Define if your system supports the epoll system calls])
    	needsignal=yes
    fi
    if test "x$ac_cv_header_sys_epoll_h" = "xyes"; then
    	if test "x$haveepoll" = "xno" ; then
    		AC_MSG_CHECKING(for epoll system call)
    		AC_RUN_IFELSE(
          [AC_LANG_PROGRAM([[
    #include <stdint.h>
    #include <sys/param.h>
    #include <sys/types.h>
    #include <sys/syscall.h>
    #include <sys/epoll.h>
    #include <unistd.h>
    
    int
    epoll_create(int size)
    {
    	return (syscall(__NR_epoll_create, size));
    }
            ]],[[
    	int epfd;
    
    	epfd = epoll_create(256);
    	return (epfd == -1 ? 1 : 0);
            ]]
          )], 
          [AC_MSG_RESULT(yes)
          AC_DEFINE(HAVE_EPOLL, 1,
    	      [Define if your system supports the epoll system calls])
          needsignal=yes
          have_epoll=yes
          AC_LIBOBJ(epoll_sub)
          ], [AC_MSG_RESULT(no)], [AC_MSG_RESULT(no)]
        )
    	fi
    fi
    AM_CONDITIONAL(EPOLL_BACKEND, [test "x$haveepoll" = "xyes"])
    
    haveeventports=no
    AC_CHECK_FUNCS(port_create, [haveeventports=yes], )
    if test "x$haveeventports" = "xyes" ; then
    	AC_DEFINE(HAVE_EVENT_PORTS, 1,
    		[Define if your system supports event ports])
    	needsignal=yes
    fi
    AM_CONDITIONAL(EVPORT_BACKEND, [test "x$haveeventports" = "xyes"])
    
    havewepoll=no
    if test "x$bwin32" = "xtrue"; then
    	needsignal=yes
      if test "x$cygwin" = "xfalse"; then
        havewepoll=yes
        AC_DEFINE(HAVE_WEPOLL, 1,
          [Define if your system supports the wepoll module])
      fi
    fi
    AM_CONDITIONAL(WEPOLL_BACKEND, [test "x$havewepoll" = "xyes"])
    AM_CONDITIONAL(SIGNAL_SUPPORT, [test "x$needsignal" = "xyes"])
    
    AC_TYPE_PID_T
    AC_TYPE_SIZE_T
    AC_TYPE_SSIZE_T
    
    AC_CHECK_TYPES([uint64_t, uint32_t, uint16_t, uint8_t, uintptr_t], , ,
    [#ifdef HAVE_STDINT_H
    #include <stdint.h>
    #elif defined(HAVE_INTTYPES_H)
    #include <inttypes.h>
    #endif
    #ifdef HAVE_SYS_TYPES_H
    #include <sys/types.h>
    #endif])
    
    AC_CHECK_TYPES([fd_mask], , ,
    [#ifdef HAVE_SYS_TYPES_H
    #include <sys/types.h>
    #endif
    #ifdef HAVE_SYS_SELECT_H
    #include <sys/select.h>
    #endif])
    
    AC_CHECK_SIZEOF(long long)
    AC_CHECK_SIZEOF(long)
    AC_CHECK_SIZEOF(int)
    AC_CHECK_SIZEOF(short)
    AC_CHECK_SIZEOF(size_t)
    AC_CHECK_SIZEOF(void *)
    AC_CHECK_SIZEOF(off_t)
    AC_CHECK_SIZEOF(time_t)
    
    AC_CHECK_TYPES([struct in6_addr, struct sockaddr_in6, struct sockaddr_un, sa_family_t, struct addrinfo, struct sockaddr_storage], , ,
    [#define _GNU_SOURCE 1
    #include <sys/types.h>
    #ifdef HAVE_NETINET_IN_H
    #include <netinet/in.h>
    #endif
    #ifdef HAVE_NETINET_IN6_H
    #include <netinet/in6.h>
    #endif
    #ifdef HAVE_SYS_UN_H
    #include <sys/un.h>
    #endif
    #ifdef HAVE_SYS_SOCKET_H
    #include <sys/socket.h>
    #endif
    #ifdef HAVE_NETDB_H
    #include <netdb.h>
    #endif
    #ifdef _WIN32
    #define WIN32_WINNT 0x400
    #define _WIN32_WINNT 0x400
    #define WIN32_LEAN_AND_MEAN
    #if defined(_MSC_VER) && (_MSC_VER < 1300)
    #include <winsock.h>
    #else
    #include <winsock2.h>
    #include <ws2tcpip.h>
    #endif
    #endif
    ])
    AC_CHECK_MEMBERS([struct in6_addr.s6_addr32, struct in6_addr.s6_addr16, struct sockaddr_in.sin_len, struct sockaddr_in6.sin6_len, struct sockaddr_storage.ss_family, struct sockaddr_storage.__ss_family], , ,
    [#include <sys/types.h>
    #ifdef HAVE_NETINET_IN_H
    #include <netinet/in.h>
    #endif
    #ifdef HAVE_NETINET_IN6_H
    #include <netinet/in6.h>
    #endif
    #ifdef HAVE_SYS_SOCKET_H
    #include <sys/socket.h>
    #endif
    #ifdef _WIN32
    #define WIN32_WINNT 0x400
    #define _WIN32_WINNT 0x400
    #define WIN32_LEAN_AND_MEAN
    #if defined(_MSC_VER) && (_MSC_VER < 1300)
    #include <winsock.h>
    #else
    #include <winsock2.h>
    #include <ws2tcpip.h>
    #endif
    #endif
    ])
    
    AC_CHECK_TYPES([struct linger],,,
    [
    #ifdef HAVE_SYS_SOCKET_H
    #include <sys/socket.h>
    #endif
    #ifdef _WIN32
    #include <winsock2.h>
    #endif
    ])
    
    AC_MSG_CHECKING([for socklen_t])
    AC_COMPILE_IFELSE(
      [AC_LANG_PROGRAM([
     #include <sys/types.h>
     #ifdef _WIN32
     #include <ws2tcpip.h>
     #else
     #include <sys/socket.h>
     #endif
        ],[socklen_t x;]
      )],
    	[AC_MSG_RESULT([yes])],
      [AC_MSG_RESULT([no])
      AC_DEFINE(socklen_t, unsigned int,
    	  [Define to unsigned int if you dont have it])]
    )
    
    dnl __func__/__FUNCTION__ is not a macros in general
    AC_MSG_CHECKING([whether our compiler supports __func__])
    AC_COMPILE_IFELSE(
      [AC_LANG_PROGRAM([],
        [ const char *cp = __func__; ]
      )],
    	[ AC_DEFINE(HAVE___func__, 1, [Define to 1 if compiler have __func__])
        AC_MSG_RESULT([yes])
      ],
      [AC_MSG_RESULT([no])]
    )
    AC_MSG_CHECKING([whether our compiler supports __FUNCTION__])
    AC_COMPILE_IFELSE(
      [AC_LANG_PROGRAM([],
        [ const char *cp = __FUNCTION__; ]
      )],
    	[ AC_DEFINE(HAVE___FUNCTION__, 1, [Define to 1 if compiler have __FUNCTION__])
        AC_MSG_RESULT([yes])
      ],
      [AC_MSG_RESULT([no])]
    )
    
    dnl check if we can compile with pthreads
    have_pthreads=no
    if test x$bwin32 != xtrue && test "$enable_thread_support" != "no"; then
      ACX_PTHREAD([
    	AC_DEFINE(HAVE_PTHREADS, 1,
    		[Define if we have pthreads on this system])
    	have_pthreads=yes])
      CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
      AC_CHECK_SIZEOF(pthread_t, ,
         [AC_INCLUDES_DEFAULT()
          #include <pthread.h> ]
      )
    
      AC_CHECK_FUNCS([pthread_mutexattr_setprotocol])
    fi
    AM_CONDITIONAL(THREADS, [test "$enable_thread_support" != "no"])
    AM_CONDITIONAL(PTHREADS, [test "$have_pthreads" != "no" && test "$enable_thread_support" != "no"])
    
    dnl check if we should compile locking into the library
    if test x$enable_thread_support = xno; then
       AC_DEFINE(DISABLE_THREAD_SUPPORT, 1,
    	[Define if libevent should not be compiled with thread support])
    fi
    
    dnl check if we should hard-code the mm functions.
    if test x$enable_malloc_replacement = xno; then
      AC_DEFINE(DISABLE_MM_REPLACEMENT, 1,
            [Define if libevent should not allow replacing the mm functions])
    fi
    
    dnl check if we should hard-code debugging out
    if test x$enable_debug_mode = xno; then
      AC_DEFINE(DISABLE_DEBUG_MODE, 1,
            [Define if libevent should build without support for a debug mode])
    fi
    
    dnl check if we should enable verbose debugging
    if test x$enable_verbose_debug = xyes; then
    	CFLAGS="$CFLAGS -DUSE_DEBUG"
    fi
    
    dnl check if we have and should use OpenSSL
    AM_CONDITIONAL(OPENSSL, [test "$enable_openssl" != "no" && test "$have_openssl" = "yes"])
    
    # check if we have and should use mbedtls
    AM_CONDITIONAL(MBEDTLS, [test "$enable_mbedtls" != "no" && test "$have_mbedtls" = "yes"])
    
    dnl enable some warnings by default
    AX_CHECK_COMPILE_FLAG([-Wall], [CFLAGS="$CFLAGS -Wall"],[],[-Werror])
    
    dnl Disable the strict-aliasing optimization, since it breaks
    dnl our sockaddr-handling code in strange ways.
    dnl See 52eb4951302554dd696d6a0120ad5d3f6cffb7bb.
    AX_CHECK_COMPILE_FLAG([-fno-strict-aliasing], [CFLAGS="$CFLAGS -fno-strict-aliasing"],[],[-Werror])
    
    dnl Add warnings which we use in development but not for releases.
    if test x$enable_gcc_warnings != xno && test "$GCC" = "yes"; then
    
      dnl -W is the same as -Wextra
      AX_CHECK_COMPILE_FLAG([-W], [CFLAGS="$CFLAGS -W"],[],[-Werror])
    
      dnl The AX_CHECK_COMPILE_FLAG macro ignores warnings, so -Werror is used
      dnl to convert warnings into errors and prevent the addition of unknown flags.
      AX_CHECK_COMPILE_FLAG([-Waddress],[CFLAGS="$CFLAGS -Waddress"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wbad-function-cast],[CFLAGS="$CFLAGS -Wbad-function-cast"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wdeclaration-after-statement],[CFLAGS="$CFLAGS -Wdeclaration-after-statement"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wfloat-equal],[CFLAGS="$CFLAGS -Wfloat-equal"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Winit-self],[CFLAGS="$CFLAGS -Winit-self"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wlogical-op],[CFLAGS="$CFLAGS -Wlogical-op"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wmissing-declarations],[CFLAGS="$CFLAGS -Wmissing-declarations"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wmissing-field-initializers],[CFLAGS="$CFLAGS -Wmissing-field-initializers"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wmissing-prototypes],[CFLAGS="$CFLAGS -Wmissing-prototypes"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wnested-externs],[CFLAGS="$CFLAGS -Wnested-externs"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wnormalized=id],[CFLAGS="$CFLAGS -Wnormalized=id"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Woverride-init],[CFLAGS="$CFLAGS -Woverride-init"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wpointer-arith],[CFLAGS="$CFLAGS -Wpointer-arith"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wredundant-decls],[CFLAGS="$CFLAGS -Wredundant-decls"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wstrict-prototypes],[CFLAGS="$CFLAGS -Wstrict-prototypes"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wundef],[CFLAGS="$CFLAGS -Wundef"],[],[-Werror])
      AX_CHECK_COMPILE_FLAG([-Wwrite-strings],[CFLAGS="$CFLAGS -Wwrite-strings"],[],[-Werror])
    
      dnl Convert warnings into errors
      if test x$enable_gcc_warnings = xyes; then
        AX_CHECK_COMPILE_FLAG([-Werror], [CFLAGS="$CFLAGS -Werror"])
      fi
    
      dnl Disable warnings for unused paramaters
      AX_CHECK_COMPILE_FLAG([-Wno-unused-parameter], [CFLAGS="$CFLAGS -Wno-unused-parameter"],[],[-Werror])
    
      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [
      #if !defined(__clang__)
      #error
      #endif])], have_clang=yes, have_clang=no)
    
      if test x$have_clang = xyes; then
        dnl Disable unused-function warnings. These trigger for minheap-internal.h.
        AX_CHECK_COMPILE_FLAG([-Wno-unused-function], [CFLAGS="$CFLAGS -Wno-unused-function"],[],[-Werror])
    
        case "$host_os" in
          darwin*)
            dnl Clang on macOS emits warnings for each directory specified which
            dnl isn't "used", generating a lot of build noise.
            AX_CHECK_COMPILE_FLAG([-Qunused-arguments], [CFLAGS="$CFLAGS -Qunused-arguments"],[],[-Werror])
        esac
      fi
    fi
    
    LIBEVENT_GC_SECTIONS=
    if test "$GCC" = yes && test "$enable_function_sections" = yes ; then
        AC_CACHE_CHECK(
    	[if linker supports omitting unused code and data],
    	[libevent_cv_gc_sections_runs],
    	[
    	    dnl  NetBSD will link but likely not run with --gc-sections
    	    dnl  http://bugs.ntp.org/1844
    	    dnl  http://gnats.netbsd.org/40401
    	    dnl  --gc-sections causes attempt to load as linux elf, with
    	    dnl  wrong syscalls in place.  Test a little gauntlet of
    	    dnl  simple stdio read code checking for errors, expecting
    	    dnl  enough syscall differences that the NetBSD code will
    	    dnl  fail even with Linux emulation working as designed.
    	    dnl  A shorter test could be refined by someone with access
    	    dnl  to a NetBSD host with Linux emulation working.
    	    origCFLAGS="$CFLAGS"
    	    CFLAGS="$CFLAGS -Wl,--gc-sections"
    	    AC_LINK_IFELSE(
    		[AC_LANG_PROGRAM(
    		    [[
    			#include <stdlib.h>
    			#include <stdio.h>
    		    ]],
    		    [[
    			FILE *	fpC;
    			char	buf[32];
    			size_t	cch;
    			int	read_success_once;
    
    			fpC = fopen("conftest.c", "r");
    			if (NULL == fpC)
    				exit(1);
    			do {
    				cch = fread(buf, sizeof(buf), 1, fpC);
    				read_success_once |= (0 != cch);
    			} while (0 != cch);
    			if (!read_success_once)
    				exit(2);
    			if (!feof(fpC))
    				exit(3);
    			if (0 != fclose(fpC))
    				exit(4);
    
    			exit(EXIT_SUCCESS);
    		    ]]
    		)],
    		[
                        dnl We have to do this invocation manually so that we can
                        dnl get the output of conftest.err to make sure it doesn't
                        dnl mention gc-sections.
    		    if test "X$cross_compiling" = "Xyes" || grep gc-sections conftest.err ; then
    			libevent_cv_gc_sections_runs=no
    		    else
    			libevent_cv_gc_sections_runs=no
    			./conftest >/dev/null 2>&1 && libevent_cv_gc_sections_runs=yes
    		    fi
    		],
    		[libevent_cv_gc_sections_runs=no]
    	    )
    	    CFLAGS="$origCFLAGS"
    	    AS_UNSET([origCFLAGS])
    	]
        )
        case "$libevent_cv_gc_sections_runs" in
         yes)
    	CFLAGS="-ffunction-sections -fdata-sections $CFLAGS"
    	LIBEVENT_GC_SECTIONS="-Wl,--gc-sections"
    	;;
        esac
    fi
    AC_SUBST([LIBEVENT_GC_SECTIONS])
    
    AM_CONDITIONAL([INSTALL_LIBEVENT], [test "$enable_libevent_install" = "yes"])
    
    dnl Doxygen support
    DX_HTML_FEATURE(ON)
    DX_MAN_FEATURE(OFF)
    DX_RTF_FEATURE(OFF)
    DX_XML_FEATURE(OFF)
    DX_PDF_FEATURE(OFF)
    DX_PS_FEATURE(OFF)
    DX_CHM_FEATURE(OFF)
    DX_CHI_FEATURE(OFF)
    DX_INIT_DOXYGEN([libevent], [${top_srcdir}/Doxyfile], [doxygen])
    
    AM_CONDITIONAL([ENABLE_DOXYGEN], [test "$DX_FLAG_doc" = "1"])
    AM_CONDITIONAL([ENABLE_DOXYGEN_MAN], [test "$DX_FLAG_man" = "1"])
    
    AC_CONFIG_FILES( [libevent.pc libevent_mbedtls.pc libevent_openssl.pc libevent_pthreads.pc libevent_core.pc libevent_extra.pc] )
    AC_OUTPUT(Makefile)