configure.ac

AC_PREREQ(2.52)
m4_include([version.m4])
m4_include([m4/c99-backport.m4])
AC_INIT([memcached], [VERSION_NUMBER], [memcached@googlegroups.com])
AC_CANONICAL_HOST
AC_CONFIG_SRCDIR([memcached.c])
AM_INIT_AUTOMAKE([foreign])
AM_CONFIG_HEADER([config.h])

AC_PROG_CC

is_darwin=no

case "${host_os}" in
   darwin*)
   is_darwin=yes
   ;;
esac

AM_CONDITIONAL([DARWIN], [test "$is_darwin" = "yes"])

dnl **********************************************************************
dnl DETECT_ICC ([ACTION-IF-YES], [ACTION-IF-NO])
dnl
dnl check if this is the Intel ICC compiler, and if so run the ACTION-IF-YES
dnl sets the $ICC variable to "yes" or "no"
dnl **********************************************************************
AC_DEFUN([DETECT_ICC],
[
    ICC="no"
    AC_MSG_CHECKING([for icc in use])
    if test "$GCC" = "yes"; then
       dnl check if this is icc acting as gcc in disguise
       AC_EGREP_CPP([^__INTEL_COMPILER], [__INTEL_COMPILER],
         AC_MSG_RESULT([no])
         [$2],
         AC_MSG_RESULT([yes])
         [$1]
         ICC="yes")
    else
       AC_MSG_RESULT([no])
       [$2]
    fi
])

DETECT_ICC([], [])

dnl **********************************************************************
dnl DETECT_CLANG ([ACTION-IF-YES], [ACTION-IF-NO])
dnl
dnl check if compiler is clang, and if so run the ACTION-IF-YES sets the
dnl $CLANG variable to "yes" or "no"
dnl **********************************************************************
AC_DEFUN([DETECT_CLANG],
[
    AC_MSG_CHECKING([for clang in use])
    AC_COMPILE_IFELSE(
    [AC_LANG_PROGRAM([], [[
    #ifndef __clang__
           not clang
    #endif
    ]])],
    [CLANG=yes], [CLANG=no])
    AC_MSG_RESULT([$CLANG])
    AS_IF([test "$CLANG" = "yes"],[$1],[$2])
])
DETECT_CLANG([],[])

dnl **********************************************************************
dnl DETECT_SUNCC ([ACTION-IF-YES], [ACTION-IF-NO])
dnl
dnl check if this is the Sun Studio compiler, and if so run the ACTION-IF-YES
dnl sets the $SUNCC variable to "yes" or "no"
dnl **********************************************************************
AC_DEFUN([DETECT_SUNCC],
[
    AC_CHECK_DECL([__SUNPRO_C], [SUNCC="yes"], [SUNCC="no"])
    AS_IF(test "x$SUNCC" = "xyes", [$1], [$2])

])

DETECT_SUNCC([CFLAGS="-mt $CFLAGS"], [])
AS_IF([test "$ICC" = "yes" -o "$GCC" = "yes"],
[
    AS_IF(test "$CLANG" = "no",[CFLAGS="$CFLAGS -pthread"])
])

dnl clang will error .arch_extension crc32 assembler directives to allow
dnl assembling crc instructions without this
AS_IF(test "$CLANG" = "yes",[CFLAGS="$CFLAGS -Wno-language-extension-token"])

if test "$ICC" = "no"; then
   AC_PROG_CC_C99
fi

AM_PROG_CC_C_O
AC_PROG_INSTALL

AC_ARG_ENABLE(extstore,
  [AS_HELP_STRING([--disable-extstore], [Disable external storage (extstore)])])

AC_ARG_ENABLE(seccomp,
  [AS_HELP_STRING([--enable-seccomp],[Enable seccomp restrictions EXPERIMENTAL])])

AC_ARG_ENABLE(sasl,
  [AS_HELP_STRING([--enable-sasl],[Enable SASL authentication])])

AC_ARG_ENABLE(sasl_pwdb,
  [AS_HELP_STRING([--enable-sasl-pwdb],[Enable plaintext password db])])

AS_IF([test "x$enable_sasl_pwdb" = "xyes"],
      [enable_sasl=yes ])

AC_ARG_ENABLE(tls,
  [AS_HELP_STRING([--enable-tls], [Enable Transport Layer Security EXPERIMENTAL ])])


AC_ARG_ENABLE(asan,
  [AS_HELP_STRING([--enable-asan], [Compile with ASAN EXPERIMENTAL ])])

AC_ARG_ENABLE(static,
  [AS_HELP_STRING([--enable-static], [Compile a statically linked binary])])

AC_ARG_ENABLE(unix_socket,
  [AS_HELP_STRING([--disable-unix-socket], [Disable unix domain socket])])

AC_ARG_ENABLE(proxy,
  [AS_HELP_STRING([--enable-proxy], [Enable proxy code EXPERIMENTAL])])

AC_ARG_ENABLE(proxy-uring,
  [AS_HELP_STRING([--enable-proxy-uring], [Enable proxy io_uring code EXPERIMENTAL])])

AC_ARG_ENABLE(proxy-tls,
  [AS_HELP_STRING([--enable-proxy-tls], [Enable proxy io_uring code EXPERIMENTAL])])

AC_ARG_ENABLE(werror,
  [AS_HELP_STRING([--enable-werror], [Enable -Werror])])

AC_ARG_ENABLE(large-client-flags,
  [AS_HELP_STRING([--enable-large-client-flags], [Change client flags from 32bit to 64bit EXPERIMENTAL])])

dnl **********************************************************************
dnl DETECT_SASL_CB_GETCONF
dnl
dnl check if we can use SASL_CB_GETCONF
dnl **********************************************************************
AC_DEFUN([AC_C_DETECT_SASL_CB_GETCONF],
[
    AC_CACHE_CHECK([for SASL_CB_GETCONF],
        [ac_cv_c_sasl_cb_getconf],
        [AC_TRY_COMPILE(
            [
#include <sasl/sasl.h>
            ], [
unsigned long val = SASL_CB_GETCONF;
            ],
            [ ac_cv_c_sasl_cb_getconf=yes ],
            [ ac_cv_c_sasl_cb_getconf=no ])
        ])
    AS_IF([test "$ac_cv_c_sasl_cb_getconf" = "yes"],
          [AC_DEFINE([HAVE_SASL_CB_GETCONF], 1,
                     [Set to nonzero if your SASL implementation supports SASL_CB_GETCONF])])
])

dnl **********************************************************************
dnl DETECT_SASL_CB_GETCONFPATH
dnl
dnl check if we can use SASL_CB_GETCONFPATH
dnl **********************************************************************
AC_DEFUN([AC_C_DETECT_SASL_CB_GETCONFPATH],
[
    AC_CACHE_CHECK([for SASL_CB_GETCONFPATH],
        [ac_cv_c_sasl_cb_getconfpath],
        [AC_TRY_COMPILE(
            [
#include <sasl/sasl.h>
            ], [
unsigned long val = SASL_CB_GETCONFPATH;
            ],
            [ ac_cv_c_sasl_cb_getconfpath=yes ],
            [ ac_cv_c_sasl_cb_getconfpath=no ])
        ])
    AS_IF([test "$ac_cv_c_sasl_cb_getconfpath" = "yes"],
          [AC_DEFINE([HAVE_SASL_CB_GETCONFPATH], 1,
                     [Set to nonzero if your SASL implementation supports SASL_CB_GETCONFPATH])])
])

AC_CHECK_HEADERS([sasl/sasl.h])
if test "x$enable_sasl" = "xyes"; then
  AC_C_DETECT_SASL_CB_GETCONF
  AC_C_DETECT_SASL_CB_GETCONFPATH
  AC_DEFINE([ENABLE_SASL],1,[Set to nonzero if you want to include SASL])
  AC_SEARCH_LIBS([sasl_server_init], [sasl2 sasl], [],
    [
      AC_MSG_ERROR([Failed to locate the library containing sasl_server_init])
    ])

  AS_IF([test "x$enable_sasl_pwdb" = "xyes"],
        [AC_DEFINE([ENABLE_SASL_PWDB], 1,
                   [Set to nonzero if you want to enable a SASL pwdb])])
fi

AC_ARG_ENABLE(dtrace,
  [AS_HELP_STRING([--enable-dtrace],[Enable dtrace probes])])
if test "x$enable_dtrace" = "xyes"; then
  AC_PATH_PROG([DTRACE], [dtrace], "no", [/usr/sbin:$PATH])
  if test "x$DTRACE" != "xno"; then
    AC_DEFINE([ENABLE_DTRACE],1,[Set to nonzero if you want to include DTRACE])
    build_dtrace=yes
    $DTRACE -h -o conftest.h -s memcached_dtrace.d 2>/dev/zero
    if test $? -eq 0
    then
        dtrace_instrument_obj=yes
        rm conftest.h
        # on Mac probe id are generated with $
        if test "$is_darwin" = "yes"; then
          CFLAGS="$CFLAGS -Wno-dollar-in-identifier-extension"
        fi
    fi

    if test "`which tr`" = "/usr/ucb/tr"; then
        AC_MSG_ERROR([Please remove /usr/ucb from your path. See man standards for more info])
    fi
  else
    AC_MSG_ERROR([Need dtrace binary and OS support.])
  fi
fi

if test "x$enable_extstore" != "xno"; then
    AC_DEFINE([EXTSTORE],1,[Set to nonzero if you want to enable extstore])
fi

if test "x$enable_tls" = "xyes"; then
    AC_DEFINE([TLS],1,[Set to nonzero if you want to enable TLS])
fi

if test "x$enable_asan" = "xyes"; then
    AC_DEFINE([ASAN],1,[Set to nonzero if you want to compile using ASAN])
fi

if test "x$enable_static" = "xyes"; then
    AC_DEFINE([STATIC],1,[Set to nonzero if you want to compile a statically linked binary])
fi

if test "x$enable_unix_socket" = "xno"; then
    AC_DEFINE([DISABLE_UNIX_SOCKET],1,[Set to nonzero if you want to disable unix domain socket])
fi

if test "x$enable_proxy" = "xyes"; then
    AC_DEFINE([PROXY],1,[Set to nonzero if you want to enable proxy code])
    CPPFLAGS="-Ivendor/lua/src -Ivendor/liburing/src/include $CPPFLAGS"
    dnl lua needs math lib.
    LIBS="$LIBS -lm -ldl"
fi

if test "x$enable_proxy_uring" = "xyes"; then
    AC_DEFINE([HAVE_LIBURING],1,[Set to nonzero if you want to enable proxy uring handling])
    CPPFLAGS="-Ivendor/liburing/src/include $CPPFLAGS"
fi

if test "x$enable_proxy_tls" = "xyes"; then
    if test "x$enable_tls" != "xyes"; then
        AC_MSG_ERROR([--enable-proxy-tls requires --enable-tls])
    else
        AC_DEFINE([PROXY_TLS],1,[Set to nonzero if you want to enable proxy backend tls support])
    fi
fi

if test "x$enable_large_client_flags" = "xyes"; then
    AC_DEFINE([LARGE_CLIENT_FLAGS],1,[Set to nonzero if you want 64bit client flags])
fi

AM_CONDITIONAL([BUILD_DTRACE],[test "$build_dtrace" = "yes"])
AM_CONDITIONAL([DTRACE_INSTRUMENT_OBJ],[test "$dtrace_instrument_obj" = "yes"])
AM_CONDITIONAL([ENABLE_SASL],[test "$enable_sasl" = "yes"])
AM_CONDITIONAL([ENABLE_EXTSTORE],[test "$enable_extstore" != "no"])
AM_CONDITIONAL([ENABLE_ARM_CRC32],[test "$enable_arm_crc32" = "yes"])
AM_CONDITIONAL([ENABLE_TLS],[test "$enable_tls" = "yes"])
AM_CONDITIONAL([ENABLE_ASAN],[test "$enable_asan" = "yes"])
AM_CONDITIONAL([ENABLE_STATIC],[test "$enable_static" = "yes"])
AM_CONDITIONAL([DISABLE_UNIX_SOCKET],[test "$enable_unix_socket" = "no"])
AM_CONDITIONAL([ENABLE_PROXY],[test "$enable_proxy" = "yes"])
AM_CONDITIONAL([ENABLE_PROXY_URING],[test "$enable_proxy_uring" = "yes"])
AM_CONDITIONAL([ENABLE_PROXY_TLS],[test "$enable_proxy_tls" = "yes"])
AM_CONDITIONAL([LARGE_CLIENT_FLAGS],[test "$enable_large_client_flags" = "yes"])


AC_SUBST(DTRACE)
AC_SUBST(DTRACEFLAGS)
AC_SUBST(ENABLE_SASL)
AC_SUBST(PROFILER_LDFLAGS)

AC_ARG_ENABLE(coverage,
  [AS_HELP_STRING([--disable-coverage],[Disable code coverage])])

if test "x$enable_coverage" != "xno"; then
   if test "$GCC" = "yes" -a "$ICC" != "yes" -a "$CLANG" != "yes"
   then
      CFLAGS="$CFLAGS -pthread"
      AC_PATH_PROG([PROFILER], [gcov], "no", [$PATH])
      if test "x$PROFILER" != "xno"; then
         # Issue 97: The existence of gcov doesn't mean we have -lgcov
         AC_CHECK_LIB(gcov, main,
                    [
                      PROFILER_FLAGS="-fprofile-arcs -ftest-coverage"
                      PROFILER_LDFLAGS="-lgcov"
                    ], [
                      PROFILER_FLAGS=
                      PROFILER_LDFLAGS=
                    ])
      fi
   elif test "$SUNCC" = "yes"
   then
      AC_PATH_PROG([PROFILER], [tcov], "no", [$PATH])
      if test "x$PROFILER" != "xno"; then
         PROFILER_FLAGS=-xprofile=tcov
      fi
   elif test "x$CLANG" != "xno"
   then
      AC_PATH_PROG([PROFILER], [gcov], "no", [$PATH])
      if test "x$PROFILER" != "xno"
      then
          PROFILER_FLAGS="-fprofile-arcs -ftest-coverage"
          PROFILER_LDFLAGS=
      fi
   fi
fi
AC_SUBST(PROFILER_FLAGS)


AC_ARG_ENABLE(64bit,
  [AS_HELP_STRING([--enable-64bit],[build 64bit version])])
if test "x$enable_64bit" = "xyes"
then
    org_cflags=$CFLAGS
    CFLAGS=-m64
    AC_RUN_IFELSE(
      [AC_LANG_PROGRAM([], [dnl
return sizeof(void*) == 8 ? 0 : 1;
      ])
    ],[
      CFLAGS="-m64 $org_cflags"
    ],[
      AC_MSG_ERROR([Don't know how to build a 64-bit object.])
    ],[
       dnl cross compile
       AC_MSG_WARN([Assuming no extra CFLAGS are required for cross-compiling 64bit version.])
    ])
fi

dnl Check if data pointer is 64bit or not
AC_CHECK_SIZEOF([void *])

# Issue 213: Search for clock_gettime to help people linking
#            with a static version of libevent
AC_SEARCH_LIBS(clock_gettime, rt)
# Issue 214: Search for the network libraries _before_ searching
#            for libevent (to help people linking with static libevent)
AC_SEARCH_LIBS(socket, socket)
AC_SEARCH_LIBS(gethostbyname, nsl)

trylibeventdir=""
AC_ARG_WITH(libevent,
       [  --with-libevent=PATH     Specify path to libevent installation ],
       [
                if test "x$withval" != "xno" ; then
                        trylibeventdir=$withval
                fi
       ]
)

dnl ------------------------------------------------------
dnl libevent detection.  swiped from Tor.  modified a bit.

LIBEVENT_URL=https://www.monkey.org/~provos/libevent/

AC_CACHE_CHECK([for libevent directory], ac_cv_libevent_dir, [
  saved_LIBS="$LIBS"
  saved_LDFLAGS="$LDFLAGS"
  saved_CPPFLAGS="$CPPFLAGS"
  le_found=no
  for ledir in $trylibeventdir "" $prefix /usr/local ; do
    LDFLAGS="$saved_LDFLAGS"
    LIBS="-levent $saved_LIBS"

    # Skip the directory if it isn't there.
    if test ! -z "$ledir" -a ! -d "$ledir" ; then
       continue;
    fi
    if test ! -z "$ledir" ; then
      if test -d "$ledir/lib" ; then
        LDFLAGS="-L$ledir/lib $LDFLAGS"
      else
        LDFLAGS="-L$ledir $LDFLAGS"
      fi
      if test -d "$ledir/include" ; then
        CPPFLAGS="-I$ledir/include $CPPFLAGS"
      else
        CPPFLAGS="-I$ledir $CPPFLAGS"
      fi
    fi
    # Can I compile and link it?
    AC_TRY_LINK([#include <sys/time.h>
#include <sys/types.h>
#include <event.h>], [ event_init(); ],
       [ libevent_linked=yes ], [ libevent_linked=no ])
    if test $libevent_linked = yes; then
       if test ! -z "$ledir" ; then
         ac_cv_libevent_dir=$ledir
         _myos=`echo $target_os | cut -f 1 -d .`
         AS_IF(test "$SUNCC" = "yes" -o "x$_myos" = "xsolaris2",
               [saved_LDFLAGS="$saved_LDFLAGS -Wl,-R$ledir/lib"],
               [AS_IF(test "$GCC" = "yes",
                     [saved_LDFLAGS="$saved_LDFLAGS -Wl,-rpath,$ledir/lib"])])
       else
         ac_cv_libevent_dir="(system)"
       fi
       le_found=yes
       break
    fi
  done
  LIBS="$saved_LIBS"
  LDFLAGS="$saved_LDFLAGS"
  CPPFLAGS="$saved_CPPFLAGS"
  if test $le_found = no ; then
    AC_MSG_ERROR([libevent is required.  You can get it from $LIBEVENT_URL

      If it's already installed, specify its path using --with-libevent=/dir/
])
  fi
])
LIBS="-levent $LIBS"
if test $ac_cv_libevent_dir != "(system)"; then
  if test -d "$ac_cv_libevent_dir/lib" ; then
    LDFLAGS="-L$ac_cv_libevent_dir/lib $LDFLAGS"
    le_libdir="$ac_cv_libevent_dir/lib"
  else
    LDFLAGS="-L$ac_cv_libevent_dir $LDFLAGS"
    le_libdir="$ac_cv_libevent_dir"
  fi
  if test -d "$ac_cv_libevent_dir/include" ; then
    CPPFLAGS="-I$ac_cv_libevent_dir/include $CPPFLAGS"
  else
    CPPFLAGS="-I$ac_cv_libevent_dir $CPPFLAGS"
  fi
fi

AC_RUN_IFELSE(
   [AC_LANG_PROGRAM([
#include <event.h>
   ], [dnl
const char *ver = event_get_version();
return (ver != NULL && *ver != '1') ? 0 : 1;
   ])
   ],[
     AC_DEFINE(HAVE_LIBEVENT_NEW, 1, [linked to libevent])
   ],
   [
     AC_MSG_ERROR([libevent2 is required])
   ],
   []
[])

trylibssldir=""
AC_ARG_WITH(libssl,
       [  --with-libssl=PATH     Specify path to libssl installation ],
       [
                if test "x$withval" != "xno" ; then
                        trylibssldir=$withval
                fi
       ]
)

dnl ----------------------------------------------------------------------------
dnl libssl detection.  swiped from libevent.  modified for openssl detection.

PKG_PROG_PKG_CONFIG
OPENSSL_URL=https://www.openssl.org/
if test "x$enable_tls" = "xyes"; then
  PKG_CHECK_MODULES(OPENSSL, openssl, [LIBS="$LIBS $OPENSSL_LIBS" CFLAGS="$CFLAGS $OPENSSL_CFLAGS"], [
    AC_CACHE_CHECK([for libssl directory], ac_cv_libssl_dir, [
      saved_LIBS="$LIBS"
      saved_LDFLAGS="$LDFLAGS"
      saved_CPPFLAGS="$CPPFLAGS"
      le_found=no
      for ledir in $trylibssldir "" $prefix /usr/local ; do
        LDFLAGS="$saved_LDFLAGS"
        LIBS="-lssl -lcrypto $saved_LIBS"

        # Skip the directory if it isn't there.
        if test ! -z "$ledir" -a ! -d "$ledir" ; then
          continue;
        fi
        if test ! -z "$ledir" ; then
          if test -d "$ledir/lib" ; then
            LDFLAGS="-L$ledir/lib $LDFLAGS"
          else
            LDFLAGS="-L$ledir $LDFLAGS"
          fi
          if test -d "$ledir/include" ; then
            CPPFLAGS="-I$ledir/include $CPPFLAGS"
          else
            CPPFLAGS="-I$ledir $CPPFLAGS"
          fi
        fi
        # Can I compile and link it?
        AC_TRY_LINK([#include <sys/time.h>
    #include <sys/types.h>
    #include <assert.h>
    #include <openssl/ssl.h>], [ SSL_CTX* ssl_ctx = SSL_CTX_new(TLS_server_method());
                                assert(OPENSSL_VERSION_NUMBER >= 0x10100000L);],
           [ libssl_linked=yes ], [ libssl_linked=no ])
        if test $libssl_linked = yes; then
          if test ! -z "$ledir" ; then
            ac_cv_libssl_dir=$ledir
            _myos=`echo $target_os | cut -f 1 -d .`
            AS_IF(test "$SUNCC" = "yes" -o "x$_myos" = "xsolaris2",
                  [saved_LDFLAGS="$saved_LDFLAGS -Wl,-R$ledir/lib"],
                  [AS_IF(test "$GCC" = "yes",
                        [saved_LDFLAGS="$saved_LDFLAGS -Wl,-rpath,$ledir/lib"])])
           else
             ac_cv_libssl_dir="(system)"
           fi
           le_found=yes
           break
        fi
      done
      LIBS="$saved_LIBS"
      LDFLAGS="$saved_LDFLAGS"
      CPPFLAGS="$saved_CPPFLAGS"
      if test $le_found = no ; then
        AC_MSG_ERROR([libssl (at least version 1.1.0) is required.  You can get it from $OPENSSL_URL

          If it's already installed, specify its path using --with-libssl=/dir/
    ])
      fi
    ])
    LIBS="-lssl -lcrypto $LIBS"
    if test $ac_cv_libssl_dir != "(system)"; then
      if test -d "$ac_cv_libssl_dir/lib" ; then
        LDFLAGS="-L$ac_cv_libssl_dir/lib $LDFLAGS"
        le_libdir="$ac_cv_libssl_dir/lib"
      else
        LDFLAGS="-L$ac_cv_libssl_dir $LDFLAGS"
        le_libdir="$ac_cv_libssl_dir"
      fi
      if test -d "$ac_cv_libssl_dir/include" ; then
        CPPFLAGS="-I$ac_cv_libssl_dir/include $CPPFLAGS"
      else
        CPPFLAGS="-I$ac_cv_libssl_dir $CPPFLAGS"
      fi
    fi
  ])
fi

if test "x$enable_static" = "xyes"; then
  LIBS="$LIBS -ldl"
  LDFLAGS="-static $LDFLAGS"
fi

dnl ----------------------------------------------------------------------------

AC_SEARCH_LIBS(gethugepagesizes, hugetlbfs)

AC_HEADER_STDBOOL
AH_BOTTOM([#if HAVE_STDBOOL_H
#include <stdbool.h>
#else
#define bool char
#define false 0
#define true 1
#endif ])

AC_CHECK_HEADERS([inttypes.h])
AH_BOTTOM([#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
])
AC_CHECK_HEADERS([sys/auxv.h])

dnl **********************************************************************
dnl Figure out if this system has the stupid sasl_callback_ft
dnl **********************************************************************

AC_DEFUN([AC_HAVE_SASL_CALLBACK_FT],
[AC_CACHE_CHECK(for sasl_callback_ft, ac_cv_has_sasl_callback_ft,
[
  AC_TRY_COMPILE([
    #ifdef HAVE_SASL_SASL_H
    #include <sasl/sasl.h>
    #include <sasl/saslplug.h>
    #endif
  ],[
    sasl_callback_ft a_callback;
  ],[
    ac_cv_has_sasl_callback_ft=yes
  ],[
    ac_cv_has_sasl_callback_ft=no
  ])
])
if test $ac_cv_has_sasl_callback_ft = yes; then
  AC_DEFINE(HAVE_SASL_CALLBACK_FT, 1, [we have sasl_callback_ft])
fi
])

AC_HAVE_SASL_CALLBACK_FT

dnl **********************************************************************
dnl DETECT_UINT64_SUPPORT
dnl
dnl check if we can use a uint64_t
dnl **********************************************************************
AC_DEFUN([AC_C_DETECT_UINT64_SUPPORT],
[
    AC_CACHE_CHECK([for print macros for integers (C99 section 7.8.1)],
        [ac_cv_c_uint64_support],
        [AC_TRY_COMPILE(
            [
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
#include <stdio.h>
            ], [
  uint64_t val = 0;
  fprintf(stderr, "%" PRIu64 "\n", val);
            ],
            [ ac_cv_c_uint64_support=yes ],
            [ ac_cv_c_uint64_support=no ])
        ])
])

AC_C_DETECT_UINT64_SUPPORT
AS_IF([test "x$ac_cv_c_uint64_support" = "xno"],
      [AC_MSG_WARN([

Failed to use print macros (PRIu) as defined in C99 section 7.8.1.

])])

AC_C_CONST

dnl From licq: Copyright (c) 2000 Dirk Mueller
dnl Check if the type socklen_t is defined anywhere
AC_DEFUN([AC_C_SOCKLEN_T],
[AC_CACHE_CHECK(for socklen_t, ac_cv_c_socklen_t,
[
  AC_TRY_COMPILE([
    #include <sys/types.h>
    #include <sys/socket.h>
  ],[
    socklen_t foo;
  ],[
    ac_cv_c_socklen_t=yes
  ],[
    ac_cv_c_socklen_t=no
  ])
])
if test $ac_cv_c_socklen_t = no; then
  AC_DEFINE(socklen_t, int, [define to int if socklen_t not available])
fi
])

AC_C_SOCKLEN_T

dnl Check if we're a little-endian or a big-endian system, needed by hash code
AC_C_BIGENDIAN(
  [AC_DEFINE(ENDIAN_BIG, 1, [machine is bigendian])],
  [AC_DEFINE(ENDIAN_LITTLE, 1, [machine is littleendian])],
  [AC_MSG_ERROR([Cannot detect endianness. Must pass ac_cv_c_bigendian={yes,no} to configure.])])

AC_DEFUN([AC_C_HTONLL],
[
    AC_MSG_CHECKING([for htonll])
    have_htoll="no"
    AC_TRY_LINK([
#include <sys/types.h>
#include <netinet/in.h>
#ifdef HAVE_INTTYPES_H
#include <inttypes.h> */
#endif
       ], [
          return htonll(0);
       ], [
          have_htoll="yes"
          AC_DEFINE([HAVE_HTONLL], [1], [Have ntohll])
    ], [
          have_htoll="no"
    ])

    AC_MSG_RESULT([$have_htoll])
])

AC_C_HTONLL

dnl Check whether the user's system supports pthread
AC_SEARCH_LIBS(pthread_create, pthread)
if test "x$ac_cv_search_pthread_create" = "xno"; then
  AC_MSG_ERROR([Can't enable threads without the POSIX thread library.])
fi

AC_CHECK_FUNCS(mlockall)
AC_CHECK_FUNCS(getpagesizes)
AC_CHECK_FUNCS(sysconf)
AC_CHECK_FUNCS(memcntl)
AC_CHECK_FUNCS(clock_gettime)
AC_CHECK_FUNCS(preadv)
AC_CHECK_FUNCS(pread)
AC_CHECK_FUNCS(eventfd)
AC_CHECK_FUNCS([pthread_setname_np],[AC_DEFINE(HAVE_PTHREAD_SETNAME_NP, 1, [Define to 1 if support pthread_setname_np])])
AC_CHECK_FUNCS([accept4], [AC_DEFINE(HAVE_ACCEPT4, 1, [Define to 1 if support accept4])])
AC_CHECK_FUNCS([getopt_long], [AC_DEFINE(HAVE_GETOPT_LONG, 1, [Define to 1 if support getopt_long])])

dnl Need to disable opt for alignment check. GCC is too clever and turns this
dnl into wide stores and no cmp under O2.
AC_DEFUN([AC_C_ALIGNMENT],
[AC_CACHE_CHECK(for alignment, ac_cv_c_alignment,
[
  AC_RUN_IFELSE(
    [AC_LANG_PROGRAM([
#include <stdlib.h>
#include <inttypes.h>
#pragma GCC optimize ("O0")
    ], [
       char *buf = malloc(32);

       uint64_t *ptr = (uint64_t*)(buf+2);
       // catch sigbus, etc.
       *ptr = 0x1;

       // catch unaligned word access (ARM cpus)
#ifdef ENDIAN_BIG
#define ALIGNMENT 0x02030405
#else
#define ALIGNMENT 0x05040302
#endif
       *(buf + 0) = 1;
       *(buf + 1) = 2;
       *(buf + 2) = 3;
       *(buf + 3) = 4;
       *(buf + 4) = 5;
       int* i = (int*)(buf+1);
       return (ALIGNMENT == *i) ? 0 : 1;
    ])
  ],[
    ac_cv_c_alignment=none
  ],[
    ac_cv_c_alignment=need
  ],[
    dnl cross compile
    ac_cv_c_alignment=maybe
  ])
])
AS_IF([test $ac_cv_c_alignment = need],
  [AC_DEFINE(NEED_ALIGN, 1, [Machine need alignment])])
AS_IF([test $ac_cv_c_alignment = maybe],
  [AC_MSG_WARN([Assuming aligned access is required when cross-compiling])
   AC_DEFINE(NEED_ALIGN, 1, [Machine need alignment])])
])

AC_C_ALIGNMENT

dnl Check for our specific usage of GCC atomics.
dnl These were added in 4.1.2, but 32bit OS's may lack shorts and 4.1.2
dnl lacks testable defines.
have_gcc_atomics=no
AC_MSG_CHECKING(for GCC atomics)
AC_TRY_LINK([],[
  unsigned short a;
  unsigned short b;
  b = __sync_add_and_fetch(&a, 1);
  b = __sync_sub_and_fetch(&a, 2);
  ],[have_gcc_atomics=yes
  AC_DEFINE(HAVE_GCC_ATOMICS, 1, [GCC Atomics available])])
AC_MSG_RESULT($have_gcc_atomics)

dnl Check for usage of 64bit atomics
dnl 32bit systems shouldn't have these.
have_gcc_64atomics=no
AC_MSG_CHECKING(for GCC 64bit atomics)
AC_TRY_LINK([#include <inttypes.h>
   ],[
  uint64_t a;
  uint64_t b;
  b = __sync_add_and_fetch(&a, 1);
  b = __sync_sub_and_fetch(&a, 2);
  ],[have_gcc_64atomics=yes
  AC_DEFINE(HAVE_GCC_64ATOMICS, 1, [GCC 64bit Atomics available])])
AC_MSG_RESULT($have_gcc_64atomics)

dnl Check for the requirements for running memcached with less privileges
dnl than the default privilege set. On Solaris we need setppriv and priv.h
dnl If you want to add support for other platforms you should check for
dnl your requirements, define HAVE_DROP_PRIVILEGES, and make sure you add
dnl the source file containing the implementation into memcached_SOURCE
dnl in Makefile.am
AC_CHECK_FUNCS(setppriv, [
   AC_CHECK_HEADER(priv.h, [
      AC_DEFINE([HAVE_DROP_PRIVILEGES], 1,
         [Define this if you have an implementation of drop_privileges()])
      build_solaris_privs=yes
   ], [])
],[])

AS_IF([test "x$enable_seccomp" = "xyes" ], [
   AC_CHECK_LIB(seccomp, seccomp_rule_add, [
      AC_DEFINE([HAVE_DROP_PRIVILEGES], 1,
         [Define this if you have an implementation of drop_privileges()])
      build_linux_privs=yes
      AC_DEFINE([HAVE_DROP_WORKER_PRIVILEGES], 1,
         [Define this if you have an implementation of drop_worker_privileges()])
      build_linux_privs=yes
   ], [])
])

AC_CHECK_FUNCS(pledge, [
   AC_CHECK_HEADER(unistd.h, [
      AC_DEFINE([HAVE_DROP_PRIVILEGES], 1,
         [Define this if you have an implementation of drop_privileges()])
      build_openbsd_privs=yes
   ], [])
],[])

AC_CHECK_FUNCS(cap_enter, [
   AC_CHECK_HEADER(sys/capsicum.h, [
      AC_DEFINE([HAVE_DROP_PRIVILEGES], 1,
         [Define this if you have an implementation of drop_privileges()])
      build_freebsd_privs=yes
   ], [])
],[])

AC_CHECK_FUNCS(sandbox_init, [
   AC_CHECK_HEADER(sandbox.h, [
      AC_DEFINE([HAVE_DROP_PRIVILEGES], 1,
         [Define this if you have an implementation of drop_privileges()])
      build_darwin_privs=yes
   ], [])
],[])



AM_CONDITIONAL([BUILD_SOLARIS_PRIVS],[test "$build_solaris_privs" = "yes"])
AM_CONDITIONAL([BUILD_LINUX_PRIVS],[test "$build_linux_privs" = "yes"])
AM_CONDITIONAL([BUILD_OPENBSD_PRIVS],[test "$build_openbsd_privs" = "yes"])
AM_CONDITIONAL([BUILD_FREEBSD_PRIVS],[test "$build_freebsd_privs" = "yes"])
AM_CONDITIONAL([BUILD_DARWIN_PRIVS],[test "$build_darwin_privs" = "yes"])

AC_ARG_ENABLE(docs,
  [AS_HELP_STRING([--disable-docs],[Disable documentation generation])])

AC_PATH_PROG([XML2RFC], [xml2rfc], "no")
AC_PATH_PROG([XSLTPROC], [xsltproc], "no")

AM_CONDITIONAL([BUILD_SPECIFICATIONS],
               [test "x$enable_docs" != "xno" -a "x$XML2RFC" != "xno" -a "x$XSLTPROC" != "xno"])


if test "x$enable_werror" = "xyes"; then
   CFLAGS="$CFLAGS -Werror"
fi

dnl Let the compiler be a bit more picky. Please note that you cannot
dnl specify these flags to the compiler before AC_CHECK_FUNCS, because
dnl the test program will generate a compilation warning and hence fail
dnl to detect the function ;-)
if test "$ICC" = "yes"
then
   dnl ICC trying to be gcc.
   CFLAGS="$CFLAGS -diag-disable 187 -Wall"
   AC_DEFINE([_GNU_SOURCE],[1],[make sure IOV_MAX is defined])
elif test "$GCC" = "yes"
then
  GCC_VERSION=`$CC -dumpversion`
  CFLAGS="$CFLAGS -Wall -pedantic -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls"
  if test "x$enable_asan" = "xyes"; then
    CFLAGS="$CFLAGS -fsanitize=address"
  fi
  case $GCC_VERSION in
    4.4.*)
    CFLAGS="$CFLAGS -fno-strict-aliasing"
    ;;
  esac
  AC_DEFINE([_GNU_SOURCE],[1],[make sure IOV_MAX is defined])
elif test "$SUNCC" = "yes"
then
  CFLAGS="$CFLAGS -errfmt=error -errwarn -errshort=tags"
fi

AC_CONFIG_FILES(Makefile doc/Makefile)
AC_OUTPUT