dep-curl/acinclude.m4

#***************************************************************************
#                                  _   _ ____  _
#  Project                     ___| | | |  _ \| |
#                             / __| | | | |_) | |
#                            | (__| |_| |  _ <| |___
#                             \___|\___/|_| \_\_____|
#
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at https://curl.se/docs/copyright.html.
#
# You may opt to use, copy, modify, merge, publish, distribute and/or sell
# copies of the Software, and permit persons to whom the Software is
# furnished to do so, under the terms of the COPYING file.
#
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
# KIND, either express or implied.
#
# SPDX-License-Identifier: curl
#
#***************************************************************************

dnl CURL_CHECK_DEF (SYMBOL, [INCLUDES], [SILENT])
dnl -------------------------------------------------
dnl Use the C preprocessor to find out if the given object-style symbol
dnl is defined and get its expansion. This macro does not use default
dnl includes even if no INCLUDES argument is given. This macro runs
dnl silently when invoked with three arguments. If the expansion would
dnl result in a set of double-quoted strings the returned expansion is
dnl actually a single double-quoted string concatenating all them.

AC_DEFUN([CURL_CHECK_DEF], [
  AC_REQUIRE([CURL_CPP_P])
  OLDCPPFLAGS=$CPPFLAGS
  dnl CPPPFLAG comes from CURL_CPP_P
  CPPFLAGS="$CPPFLAGS $CPPPFLAG"
  AS_VAR_PUSHDEF([ac_HaveDef], [curl_cv_have_def_$1])
  AS_VAR_PUSHDEF([ac_Def], [curl_cv_def_$1])
  if test -z "$SED"; then
    AC_MSG_ERROR([SED not set. Cannot continue without SED being set.])
  fi
  if test -z "$GREP"; then
    AC_MSG_ERROR([GREP not set. Cannot continue without GREP being set.])
  fi
  ifelse($3,,[AC_MSG_CHECKING([for preprocessor definition of $1])])
  tmp_exp=""
  AC_PREPROC_IFELSE([
    AC_LANG_SOURCE(
    ifelse($2,,,[$2])[[
      #ifdef $1
      CURL_DEF_TOKEN $1
      #endif
    ]])
  ],[
    tmp_exp=`eval "$ac_cpp conftest.$ac_ext" 2>/dev/null | \
      "$GREP" CURL_DEF_TOKEN 2>/dev/null | \
      "$SED" 's/.*CURL_DEF_TOKEN[[ ]][[ ]]*//' 2>/dev/null | \
      "$SED" 's/[["]][[ ]]*[["]]//g' 2>/dev/null`
    if test -z "$tmp_exp" || test "$tmp_exp" = "$1"; then
      tmp_exp=""
    fi
  ])
  if test -z "$tmp_exp"; then
    AS_VAR_SET(ac_HaveDef, no)
    ifelse($3,,[AC_MSG_RESULT([no])])
  else
    AS_VAR_SET(ac_HaveDef, yes)
    AS_VAR_SET(ac_Def, $tmp_exp)
    ifelse($3,,[AC_MSG_RESULT([$tmp_exp])])
  fi
  AS_VAR_POPDEF([ac_Def])
  AS_VAR_POPDEF([ac_HaveDef])
  CPPFLAGS=$OLDCPPFLAGS
])


dnl CURL_CHECK_DEF_CC (SYMBOL, [INCLUDES], [SILENT])
dnl -------------------------------------------------
dnl Use the C compiler to find out only if the given symbol is defined
dnl or not, this can not find out its expansion. This macro does not use
dnl default includes even if no INCLUDES argument is given. This macro
dnl runs silently when invoked with three arguments.

AC_DEFUN([CURL_CHECK_DEF_CC], [
  AS_VAR_PUSHDEF([ac_HaveDef], [curl_cv_have_def_$1])
  ifelse($3,,[AC_MSG_CHECKING([for compiler definition of $1])])
  AC_COMPILE_IFELSE([
    AC_LANG_SOURCE(
    ifelse($2,,,[$2])[[
      int main(void)
      {
      #ifndef $1
        #error force compilation error
      #endif
        return 0;
      }
    ]])
  ],[
    tst_symbol_defined="yes"
  ],[
    tst_symbol_defined="no"
  ])
  if test "$tst_symbol_defined" = "yes"; then
    AS_VAR_SET(ac_HaveDef, yes)
    ifelse($3,,[AC_MSG_RESULT([yes])])
  else
    AS_VAR_SET(ac_HaveDef, no)
    ifelse($3,,[AC_MSG_RESULT([no])])
  fi
  AS_VAR_POPDEF([ac_HaveDef])
])


dnl CURL_CHECK_LIB_XNET
dnl -------------------------------------------------
dnl Verify if X/Open network library is required.

AC_DEFUN([CURL_CHECK_LIB_XNET], [
  AC_MSG_CHECKING([if X/Open network library is required])
  tst_lib_xnet_required="no"
  AC_COMPILE_IFELSE([
    AC_LANG_SOURCE([[
      int main(void)
      {
      #if defined(__hpux) && defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE >= 600)
      #elif defined(__hpux) && defined(_XOPEN_SOURCE_EXTENDED)
      #else
        #error force compilation error
      #endif
        return 0;
      }
    ]])
  ],[
    tst_lib_xnet_required="yes"
    LIBS="-lxnet $LIBS"
  ])
  AC_MSG_RESULT([$tst_lib_xnet_required])
])


dnl CURL_CHECK_AIX_ALL_SOURCE
dnl -------------------------------------------------
dnl Provides a replacement of traditional AC_AIX with
dnl an uniform behavior across all autoconf versions,
dnl and with our own placement rules.

AC_DEFUN([CURL_CHECK_AIX_ALL_SOURCE], [
  AH_VERBATIM([_ALL_SOURCE],
    [/* Define to 1 if OS is AIX. */
#ifndef _ALL_SOURCE
#  undef _ALL_SOURCE
#endif])
  AC_BEFORE([$0], [AC_SYS_LARGEFILE])
  AC_BEFORE([$0], [CURL_CONFIGURE_REENTRANT])
  AC_MSG_CHECKING([if OS is AIX (to define _ALL_SOURCE)])
  AC_EGREP_CPP([yes_this_is_aix],[
#ifdef _AIX
   yes_this_is_aix
#endif
  ],[
    AC_MSG_RESULT([yes])
    AC_DEFINE(_ALL_SOURCE)
  ],[
    AC_MSG_RESULT([no])
  ])
])


dnl CURL_CHECK_NATIVE_WINDOWS
dnl -------------------------------------------------
dnl Check if building a native Windows target

AC_DEFUN([CURL_CHECK_NATIVE_WINDOWS], [
  AC_CACHE_CHECK([whether build target is a native Windows one], [curl_cv_native_windows], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
      ]],[[
        #ifdef _WIN32
          int dummy = 1;
          (void)dummy;
        #else
          #error Not a native Windows build target.
        #endif
      ]])
    ],[
      curl_cv_native_windows="yes"
    ],[
      curl_cv_native_windows="no"
    ])
  ])
  AM_CONDITIONAL(DOING_NATIVE_WINDOWS, test "$curl_cv_native_windows" = "yes")
])


dnl CURL_CHECK_HEADER_LBER
dnl -------------------------------------------------
dnl Check for compilable and valid lber.h header,
dnl and check if it is needed even with ldap.h

AC_DEFUN([CURL_CHECK_HEADER_LBER], [
  AC_REQUIRE([CURL_CHECK_NATIVE_WINDOWS])
  AC_CACHE_CHECK([for lber.h], [curl_cv_header_lber_h], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        #undef inline
        #ifdef _WIN32
        #ifndef WIN32_LEAN_AND_MEAN
        #define WIN32_LEAN_AND_MEAN
        #endif
        #include <windows.h>
        #else
        #ifdef HAVE_SYS_TYPES_H
        #include <sys/types.h>
        #endif
        #endif
        #ifndef NULL
        #define NULL (void *)0
        #endif
        #include <lber.h>
      ]],[[
        BerValue *bvp = NULL;
        BerElement *bep = ber_init(bvp);
        ber_free(bep, 1);
      ]])
    ],[
      curl_cv_header_lber_h="yes"
    ],[
      curl_cv_header_lber_h="no"
    ])
  ])
  if test "$curl_cv_header_lber_h" = "yes"; then
    AC_DEFINE_UNQUOTED(HAVE_LBER_H, 1,
      [Define to 1 if you have the lber.h header file.])

    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        #undef inline
        #ifdef _WIN32
        #ifndef WIN32_LEAN_AND_MEAN
        #define WIN32_LEAN_AND_MEAN
        #endif
        #include <windows.h>
        #else
        #ifdef HAVE_SYS_TYPES_H
        #include <sys/types.h>
        #endif
        #endif
        #ifndef NULL
        #define NULL (void *)0
        #endif
        #ifndef LDAP_DEPRECATED
        #define LDAP_DEPRECATED 1
        #endif
        #include <ldap.h>
      ]],[[
        BerValue *bvp = NULL;
        BerElement *bep = ber_init(bvp);
        ber_free(bep, 1);
      ]])
    ],[
      curl_cv_need_header_lber_h="no"
    ],[
      curl_cv_need_header_lber_h="yes"
    ])

    case "$curl_cv_need_header_lber_h" in
      yes)
        AC_DEFINE_UNQUOTED(NEED_LBER_H, 1,
          [Define to 1 if you need the lber.h header file even with ldap.h])
        ;;
    esac
  fi
])


dnl CURL_CHECK_HEADER_LDAP
dnl -------------------------------------------------
dnl Check for compilable and valid ldap.h header

AC_DEFUN([CURL_CHECK_HEADER_LDAP], [
  AC_REQUIRE([CURL_CHECK_HEADER_LBER])
  AC_CACHE_CHECK([for ldap.h], [curl_cv_header_ldap_h], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        #undef inline
        #ifdef _WIN32
        #ifndef WIN32_LEAN_AND_MEAN
        #define WIN32_LEAN_AND_MEAN
        #endif
        #include <windows.h>
        #else
        #ifdef HAVE_SYS_TYPES_H
        #include <sys/types.h>
        #endif
        #endif
        #ifndef LDAP_DEPRECATED
        #define LDAP_DEPRECATED 1
        #endif
        #ifdef NEED_LBER_H
        #include <lber.h>
        #endif
        #include <ldap.h>
      ]],[[
        LDAP *ldp = ldap_init("0.0.0.0", LDAP_PORT);
        int res = ldap_unbind(ldp);
        (void)res;
      ]])
    ],[
      curl_cv_header_ldap_h="yes"
    ],[
      curl_cv_header_ldap_h="no"
    ])
  ])
  case "$curl_cv_header_ldap_h" in
    yes)
      AC_DEFINE_UNQUOTED(HAVE_LDAP_H, 1,
        [Define to 1 if you have the ldap.h header file.])
      ;;
  esac
])


dnl CURL_CHECK_HEADER_LDAP_SSL
dnl -------------------------------------------------
dnl Check for compilable and valid ldap_ssl.h header

AC_DEFUN([CURL_CHECK_HEADER_LDAP_SSL], [
  AC_REQUIRE([CURL_CHECK_HEADER_LDAP])
  AC_CACHE_CHECK([for ldap_ssl.h], [curl_cv_header_ldap_ssl_h], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        #undef inline
        #ifdef _WIN32
        #ifndef WIN32_LEAN_AND_MEAN
        #define WIN32_LEAN_AND_MEAN
        #endif
        #include <windows.h>
        #else
        #ifdef HAVE_SYS_TYPES_H
        #include <sys/types.h>
        #endif
        #endif
        #ifndef LDAP_DEPRECATED
        #define LDAP_DEPRECATED 1
        #endif
        #ifdef NEED_LBER_H
        #include <lber.h>
        #endif
        #ifdef HAVE_LDAP_H
        #include <ldap.h>
        #endif
        #include <ldap_ssl.h>
      ]],[[
        LDAP *ldp = ldapssl_init("0.0.0.0", LDAPS_PORT, 1);
        (void)ldp;
      ]])
    ],[
      curl_cv_header_ldap_ssl_h="yes"
    ],[
      curl_cv_header_ldap_ssl_h="no"
    ])
  ])
  case "$curl_cv_header_ldap_ssl_h" in
    yes)
      AC_DEFINE_UNQUOTED(HAVE_LDAP_SSL_H, 1,
        [Define to 1 if you have the ldap_ssl.h header file.])
      ;;
  esac
])


dnl CURL_CHECK_LIBS_WINLDAP
dnl -------------------------------------------------
dnl Check for libraries needed for WINLDAP support,
dnl and prepended to LIBS any needed libraries.
dnl This macro can take an optional parameter with a
dnl whitespace separated list of libraries to check
dnl before the WINLDAP default ones.

AC_DEFUN([CURL_CHECK_LIBS_WINLDAP], [
  AC_REQUIRE([CURL_CHECK_HEADER_WINBER])

  AC_MSG_CHECKING([for WINLDAP libraries])

  u_libs=""

  ifelse($1,,,[
    for x_lib in $1; do
      case "$x_lib" in
        -l*)
          l_lib="$x_lib"
          ;;
        *)
          l_lib="-l$x_lib"
          ;;
      esac
      if test -z "$u_libs"; then
        u_libs="$l_lib"
      else
        u_libs="$u_libs $l_lib"
      fi
    done
  ])

  curl_cv_save_LIBS="$LIBS"
  curl_cv_ldap_LIBS="unknown"

  for x_nlibs in '' "$u_libs" \
    '-lwldap32' ; do
    if test "$curl_cv_ldap_LIBS" = "unknown"; then
      if test -z "$x_nlibs"; then
        LIBS="$curl_cv_save_LIBS"
      else
        LIBS="$x_nlibs $curl_cv_save_LIBS"
      fi
      AC_LINK_IFELSE([
        AC_LANG_PROGRAM([[
          #undef inline
          #ifdef _WIN32
          #ifndef WIN32_LEAN_AND_MEAN
          #define WIN32_LEAN_AND_MEAN
          #endif
          #include <windows.h>
          #include <winldap.h>
          #ifdef HAVE_WINBER_H
          #include <winber.h>
          #endif
          #endif
        ]],[[
          BERVAL *bvp = NULL;
          BerElement *bep = ber_init(bvp);
          LDAP *ldp = ldap_init("0.0.0.0", LDAP_PORT);
          ULONG res = ldap_unbind(ldp);
          ber_free(bep, 1);
          (void)res;
        ]])
      ],[
        curl_cv_ldap_LIBS="$x_nlibs"
      ])
    fi
  done

  LIBS="$curl_cv_save_LIBS"

  case X-"$curl_cv_ldap_LIBS" in
    X-unknown)
      AC_MSG_RESULT([cannot find WINLDAP libraries])
      ;;
    X-)
      AC_MSG_RESULT([no additional lib required])
      ;;
    *)
      if test -z "$curl_cv_save_LIBS"; then
        LIBS="$curl_cv_ldap_LIBS"
      else
        LIBS="$curl_cv_ldap_LIBS $curl_cv_save_LIBS"
      fi
      AC_MSG_RESULT([$curl_cv_ldap_LIBS])
      ;;
  esac
])


dnl CURL_CHECK_LIBS_LDAP
dnl -------------------------------------------------
dnl Check for libraries needed for LDAP support,
dnl and prepended to LIBS any needed libraries.
dnl This macro can take an optional parameter with a
dnl whitespace separated list of libraries to check
dnl before the default ones.

AC_DEFUN([CURL_CHECK_LIBS_LDAP], [
  AC_REQUIRE([CURL_CHECK_HEADER_LDAP])

  AC_MSG_CHECKING([for LDAP libraries])

  u_libs=""

  ifelse($1,,,[
    for x_lib in $1; do
      case "$x_lib" in
        -l*)
          l_lib="$x_lib"
          ;;
        *)
          l_lib="-l$x_lib"
          ;;
      esac
      if test -z "$u_libs"; then
        u_libs="$l_lib"
      else
        u_libs="$u_libs $l_lib"
      fi
    done
  ])

  curl_cv_save_LIBS="$LIBS"
  curl_cv_ldap_LIBS="unknown"

  for x_nlibs in '' "$u_libs" \
    '-lldap' \
    '-lldap -llber' \
    '-llber -lldap' \
    '-lldapssl -lldapx -lldapsdk' \
    '-lldapsdk -lldapx -lldapssl' \
    '-lldap -llber -lssl -lcrypto'; do

    if test "$curl_cv_ldap_LIBS" = "unknown"; then
      if test -z "$x_nlibs"; then
        LIBS="$curl_cv_save_LIBS"
      else
        LIBS="$x_nlibs $curl_cv_save_LIBS"
      fi
      AC_LINK_IFELSE([
        AC_LANG_PROGRAM([[
          #undef inline
          #ifdef _WIN32
          #ifndef WIN32_LEAN_AND_MEAN
          #define WIN32_LEAN_AND_MEAN
          #endif
          #include <windows.h>
          #else
          #ifdef HAVE_SYS_TYPES_H
          #include <sys/types.h>
          #endif
          #endif
          #ifndef NULL
          #define NULL (void *)0
          #endif
          #ifndef LDAP_DEPRECATED
          #define LDAP_DEPRECATED 1
          #endif
          #ifdef NEED_LBER_H
          #include <lber.h>
          #endif
          #ifdef HAVE_LDAP_H
          #include <ldap.h>
          #endif
        ]],[[
          BerValue *bvp = NULL;
          BerElement *bep = ber_init(bvp);
          LDAP *ldp = ldap_init("0.0.0.0", LDAP_PORT);
          int res = ldap_unbind(ldp);
          ber_free(bep, 1);
          (void)res;
        ]])
      ],[
        curl_cv_ldap_LIBS="$x_nlibs"
      ])
    fi
  done

  LIBS="$curl_cv_save_LIBS"

  case X-"$curl_cv_ldap_LIBS" in
    X-unknown)
      AC_MSG_RESULT([cannot find LDAP libraries])
      ;;
    X-)
      AC_MSG_RESULT([no additional lib required])
      ;;
    *)
      if test -z "$curl_cv_save_LIBS"; then
        LIBS="$curl_cv_ldap_LIBS"
      else
        LIBS="$curl_cv_ldap_LIBS $curl_cv_save_LIBS"
      fi
      dnl FIXME: Enable when ldap was detected via pkg-config
      if false; then
        LIBCURL_PC_REQUIRES_PRIVATE="ldap $LIBCURL_PC_REQUIRES_PRIVATE"
      fi
      AC_MSG_RESULT([$curl_cv_ldap_LIBS])
      ;;
  esac
])


dnl TYPE_SOCKADDR_STORAGE
dnl -------------------------------------------------
dnl Check for struct sockaddr_storage. Most IPv6-enabled
dnl hosts have it, but AIX 4.3 is one known exception.

AC_DEFUN([TYPE_SOCKADDR_STORAGE],
[
   AC_CHECK_TYPE([struct sockaddr_storage],
     AC_DEFINE(HAVE_STRUCT_SOCKADDR_STORAGE, 1,
       [if struct sockaddr_storage is defined]), ,
   [
     #undef inline
     #ifdef _WIN32
     #ifndef WIN32_LEAN_AND_MEAN
     #define WIN32_LEAN_AND_MEAN
     #endif
     #include <winsock2.h>
     #else
     #ifdef HAVE_SYS_TYPES_H
     #include <sys/types.h>
     #endif
     #include <sys/socket.h>
     #ifdef HAVE_NETINET_IN_H
     #include <netinet/in.h>
     #endif
     #ifdef HAVE_ARPA_INET_H
     #include <arpa/inet.h>
     #endif
     #endif
   ])
])

dnl CURL_CHECK_FUNC_RECV
dnl -------------------------------------------------
dnl Test if the socket recv() function is available,

AC_DEFUN([CURL_CHECK_FUNC_RECV], [
  AC_REQUIRE([CURL_CHECK_NATIVE_WINDOWS])
  AC_REQUIRE([CURL_INCLUDES_BSDSOCKET])
  AC_CHECK_HEADERS(sys/types.h)

  AC_MSG_CHECKING([for recv])
  AC_LINK_IFELSE([
    AC_LANG_PROGRAM([[
      #undef inline
      #ifdef _WIN32
      #ifndef WIN32_LEAN_AND_MEAN
      #define WIN32_LEAN_AND_MEAN
      #endif
      #include <winsock2.h>
      #else
      $curl_includes_bsdsocket
      #ifdef HAVE_SYS_TYPES_H
      #include <sys/types.h>
      #endif
      #include <sys/socket.h>
      #endif
    ]],[[
      recv(0, 0, 0, 0);
    ]])
  ],[
    AC_MSG_RESULT([yes])
    curl_cv_recv="yes"
  ],[
    AC_MSG_RESULT([no])
    curl_cv_recv="no"
  ])

  if test "$curl_cv_recv" = "yes"; then
    AC_DEFINE_UNQUOTED(HAVE_RECV, 1,
      [Define to 1 if you have the recv function.])
    curl_cv_func_recv="yes"
  else
    AC_MSG_ERROR([Unable to link function recv])
  fi
])


dnl CURL_CHECK_FUNC_SEND
dnl -------------------------------------------------
dnl Test if the socket send() function is available,

AC_DEFUN([CURL_CHECK_FUNC_SEND], [
  AC_REQUIRE([CURL_CHECK_NATIVE_WINDOWS])
  AC_REQUIRE([CURL_INCLUDES_BSDSOCKET])
  AC_CHECK_HEADERS(sys/types.h)

  AC_MSG_CHECKING([for send])
  AC_LINK_IFELSE([
    AC_LANG_PROGRAM([[
      #undef inline
      #ifdef _WIN32
      #ifndef WIN32_LEAN_AND_MEAN
      #define WIN32_LEAN_AND_MEAN
      #endif
      #include <winsock2.h>
      #else
      $curl_includes_bsdsocket
      #ifdef HAVE_SYS_TYPES_H
      #include <sys/types.h>
      #endif
      #include <sys/socket.h>
      #endif
    ]],[[
      char s[] = "";
      send(0, (void *)s, 0, 0);
    ]])
  ],[
    AC_MSG_RESULT([yes])
    curl_cv_send="yes"
  ],[
    AC_MSG_RESULT([no])
    curl_cv_send="no"
  ])

  if test "$curl_cv_send" = "yes"; then
    AC_DEFINE_UNQUOTED(HAVE_SEND, 1,
      [Define to 1 if you have the send function.])
    curl_cv_func_send="yes"
  else
    AC_MSG_ERROR([Unable to link function send])
  fi
])


dnl CURL_CHECK_STRUCT_TIMEVAL
dnl -------------------------------------------------
dnl Check for timeval struct

AC_DEFUN([CURL_CHECK_STRUCT_TIMEVAL], [
  AC_REQUIRE([CURL_CHECK_NATIVE_WINDOWS])
  AC_CHECK_HEADERS(sys/types.h)
  AC_CACHE_CHECK([for struct timeval], [curl_cv_struct_timeval], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        #undef inline
        #ifdef _WIN32
        #ifndef WIN32_LEAN_AND_MEAN
        #define WIN32_LEAN_AND_MEAN
        #endif
        #include <winsock2.h>
        #else
        #include <sys/socket.h>
        #include <sys/time.h>
        #endif
        #ifdef HAVE_SYS_TYPES_H
        #include <sys/types.h>
        #endif
        #include <time.h>
      ]],[[
        struct timeval ts;
        ts.tv_sec = 0;
        ts.tv_usec = 0;
        (void)ts;
      ]])
    ],[
      curl_cv_struct_timeval="yes"
    ],[
      curl_cv_struct_timeval="no"
    ])
  ])
  case "$curl_cv_struct_timeval" in
    yes)
      AC_DEFINE_UNQUOTED(HAVE_STRUCT_TIMEVAL, 1,
        [Define to 1 if you have the timeval struct.])
      ;;
  esac
])


dnl CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC
dnl -------------------------------------------------
dnl Check if monotonic clock_gettime is available.

AC_DEFUN([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC], [
  AC_CHECK_HEADERS(sys/types.h)
  AC_MSG_CHECKING([for monotonic clock_gettime])

  AC_COMPILE_IFELSE([
    AC_LANG_PROGRAM([[
      #ifdef HAVE_SYS_TYPES_H
      #include <sys/types.h>
      #endif
      #ifndef _WIN32
      #include <sys/time.h>
      #endif
      #include <time.h>
    ]],[[
      struct timespec ts;
      (void)clock_gettime(CLOCK_MONOTONIC, &ts);
      (void)ts;
    ]])
  ],[
    AC_MSG_RESULT([yes])
    curl_func_clock_gettime="yes"
  ],[
    AC_MSG_RESULT([no])
    curl_func_clock_gettime="no"
  ])

  dnl Definition of HAVE_CLOCK_GETTIME_MONOTONIC is intentionally postponed
  dnl until library linking and runtime checks for clock_gettime succeed.
])

dnl CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC_RAW
dnl -------------------------------------------------
dnl Check if monotonic clock_gettime is available.

AC_DEFUN([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC_RAW], [
  AC_CHECK_HEADERS(sys/types.h)
  AC_MSG_CHECKING([for raw monotonic clock_gettime])

  AC_COMPILE_IFELSE([
    AC_LANG_PROGRAM([[
      #ifdef HAVE_SYS_TYPES_H
      #include <sys/types.h>
      #endif
      #ifndef _WIN32
      #include <sys/time.h>
      #endif
      #include <time.h>
    ]],[[
      struct timespec ts;
      (void)clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
      (void)ts;
    ]])
  ],[
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_CLOCK_GETTIME_MONOTONIC_RAW, 1,
      [Define to 1 if you have the clock_gettime function and raw monotonic timer.])
  ],[
    AC_MSG_RESULT([no])
  ])
])


dnl CURL_CHECK_LIBS_CLOCK_GETTIME_MONOTONIC
dnl -------------------------------------------------
dnl If monotonic clock_gettime is available then,
dnl check and prepended to LIBS any needed libraries.

AC_DEFUN([CURL_CHECK_LIBS_CLOCK_GETTIME_MONOTONIC], [
  AC_REQUIRE([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC])

  if test "$curl_func_clock_gettime" = "yes"; then

    AC_MSG_CHECKING([for clock_gettime in libraries])

    curl_cv_save_LIBS="$LIBS"
    curl_cv_gclk_LIBS="unknown"

    for x_xlibs in '' '-lrt' '-lposix4' ; do
      if test "$curl_cv_gclk_LIBS" = "unknown"; then
        if test -z "$x_xlibs"; then
          LIBS="$curl_cv_save_LIBS"
        else
          LIBS="$x_xlibs $curl_cv_save_LIBS"
        fi
        AC_LINK_IFELSE([
          AC_LANG_PROGRAM([[
            #ifdef HAVE_SYS_TYPES_H
            #include <sys/types.h>
            #endif
            #ifndef _WIN32
            #include <sys/time.h>
            #endif
            #include <time.h>
          ]],[[
            struct timespec ts;
            (void)clock_gettime(CLOCK_MONOTONIC, &ts);
            (void)ts;
          ]])
        ],[
          curl_cv_gclk_LIBS="$x_xlibs"
        ])
      fi
    done

    LIBS="$curl_cv_save_LIBS"

    case X-"$curl_cv_gclk_LIBS" in
      X-unknown)
        AC_MSG_RESULT([cannot find clock_gettime])
        AC_MSG_WARN([HAVE_CLOCK_GETTIME_MONOTONIC is not defined])
        curl_func_clock_gettime="no"
        ;;
      X-)
        AC_MSG_RESULT([no additional lib required])
        curl_func_clock_gettime="yes"
        ;;
      *)
        if test "$dontwant_rt" = "yes"; then
          AC_MSG_WARN([needs -lrt but asked not to use it, HAVE_CLOCK_GETTIME_MONOTONIC is not defined])
          curl_func_clock_gettime="no"
        else
          if test -z "$curl_cv_save_LIBS"; then
            LIBS="$curl_cv_gclk_LIBS"
          else
            LIBS="$curl_cv_gclk_LIBS $curl_cv_save_LIBS"
          fi
          AC_MSG_RESULT([$curl_cv_gclk_LIBS])
          curl_func_clock_gettime="yes"
        fi
        ;;
    esac

    dnl only do runtime verification when not cross-compiling
    if test "$cross_compiling" != "yes" &&
       test "$curl_func_clock_gettime" = "yes"; then
      AC_MSG_CHECKING([if monotonic clock_gettime works])
      CURL_RUN_IFELSE([
        AC_LANG_PROGRAM([[
          #include <stdlib.h>
          #ifdef HAVE_SYS_TYPES_H
          #include <sys/types.h>
          #endif
          #ifndef _WIN32
          #include <sys/time.h>
          #endif
          #include <time.h>
        ]],[[
          struct timespec ts;
          if(0 == clock_gettime(CLOCK_MONOTONIC, &ts))
            return 0;
          (void)ts;
          return 1;
        ]])
      ],[
        AC_MSG_RESULT([yes])
      ],[
        AC_MSG_RESULT([no])
        AC_MSG_WARN([HAVE_CLOCK_GETTIME_MONOTONIC is not defined])
        curl_func_clock_gettime="no"
        LIBS="$curl_cv_save_LIBS"
      ])
    fi

    case "$curl_func_clock_gettime" in
      yes)
        AC_DEFINE_UNQUOTED(HAVE_CLOCK_GETTIME_MONOTONIC, 1,
          [Define to 1 if you have the clock_gettime function and monotonic timer.])
        ;;
    esac
  fi
])


dnl CURL_CHECK_LIBS_CONNECT
dnl -------------------------------------------------
dnl Verify if network connect function is already available
dnl using current libraries or if another one is required.

AC_DEFUN([CURL_CHECK_LIBS_CONNECT], [
  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])
  AC_REQUIRE([CURL_INCLUDES_BSDSOCKET])
  AC_MSG_CHECKING([for connect in libraries])
  tst_connect_save_LIBS="$LIBS"
  tst_connect_need_LIBS="unknown"
  for tst_lib in '' '-lsocket' ; do
    if test "$tst_connect_need_LIBS" = "unknown"; then
      LIBS="$tst_lib $tst_connect_save_LIBS"
      AC_LINK_IFELSE([
        AC_LANG_PROGRAM([[
          $curl_includes_winsock2
          $curl_includes_bsdsocket
          #if !defined(_WIN32) && !defined(HAVE_PROTO_BSDSOCKET_H)
            int connect(int, void*, int);
          #endif
        ]],[[
          if(0 != connect(0, 0, 0))
            return 1;
        ]])
      ],[
        tst_connect_need_LIBS="$tst_lib"
      ])
    fi
  done
  LIBS="$tst_connect_save_LIBS"

  case X-"$tst_connect_need_LIBS" in
    X-unknown)
      AC_MSG_RESULT([cannot find connect])
      AC_MSG_ERROR([cannot find connect function in libraries.])
      ;;
    X-)
      AC_MSG_RESULT([yes])
      ;;
    *)
      AC_MSG_RESULT([$tst_connect_need_LIBS])
      LIBS="$tst_connect_need_LIBS $tst_connect_save_LIBS"
      ;;
  esac
])


dnl CURL_VERIFY_RUNTIMELIBS
dnl -------------------------------------------------
dnl Verify that the shared libs found so far can be used when running
dnl programs, since otherwise the situation creates odd configure errors
dnl that are misleading people.
dnl
dnl Make sure this test is run BEFORE the first test in the script that
dnl runs anything, which at the time of this writing is the AC_CHECK_SIZEOF
dnl macro. It must also run AFTER all lib-checking macros are complete.

AC_DEFUN([CURL_VERIFY_RUNTIMELIBS], [

  dnl this test is of course not sensible if we are cross-compiling!
  if test "$cross_compiling" != "yes"; then

    dnl run a program to verify that the libs checked for previous to this
    dnl point also is available runtime!
    AC_MSG_CHECKING([runtime libs availability])
    CURL_RUN_IFELSE([
      int main(void)
      {
        return 0;
      }
    ],
    AC_MSG_RESULT([fine]),
    AC_MSG_RESULT([failed])
    AC_MSG_ERROR([one or more libs available at link-time are not available runtime. Libs used at link-time: $LIBS])
    )

    dnl if this test fails, configure has already stopped
  fi
])


dnl CURL_CHECK_CA_BUNDLE
dnl -------------------------------------------------
dnl Check if a default ca-bundle should be used
dnl
dnl regarding the paths this scans:
dnl /etc/ssl/certs/ca-certificates.crt Debian systems
dnl /etc/pki/tls/certs/ca-bundle.crt Redhat and Mandriva
dnl /usr/share/ssl/certs/ca-bundle.crt old(er) Redhat
dnl /usr/local/share/certs/ca-root-nss.crt MidnightBSD
dnl /etc/ssl/cert.pem OpenBSD, MidnightBSD (symlink)
dnl /etc/ssl/certs (CA path) SUSE, FreeBSD

AC_DEFUN([CURL_CHECK_CA_BUNDLE], [

  AC_MSG_CHECKING([default CA cert bundle/path])

  AC_ARG_WITH(ca-bundle,
AS_HELP_STRING([--with-ca-bundle=FILE],
  [Absolute path to a file containing CA certificates (example: /etc/ca-bundle.crt)])
AS_HELP_STRING([--without-ca-bundle], [Do not use a default CA bundle]),
  [
    want_ca="$withval"
    if test "x$want_ca" = "xyes"; then
      AC_MSG_ERROR([--with-ca-bundle=FILE requires a path to the CA bundle])
    fi
  ],
  [ want_ca="unset" ])
  AC_ARG_WITH(ca-path,
AS_HELP_STRING([--with-ca-path=DIRECTORY],
  [Absolute path to a directory containing CA certificates stored individually, with \
their filenames in a hash format. This option can be used with the OpenSSL, \
GnuTLS, mbedTLS and wolfSSL backends. Refer to OpenSSL c_rehash for details. \
(example: /etc/certificates)])
AS_HELP_STRING([--without-ca-path], [Do not use a default CA path]),
  [
    want_capath="$withval"
    if test "x$want_capath" = "xyes"; then
      AC_MSG_ERROR([--with-ca-path=DIRECTORY requires a path to the CA path directory])
    fi
  ],
  [ want_capath="unset"])

  ca_warning="   (warning: certs not found)"
  capath_warning="   (warning: certs not found)"
  check_capath=""

  if test "$APPLE_SECTRUST_ENABLED" = "1"; then
    ca_native="Apple SecTrust"
  elif test "$ca_native_opt" = "1"; then
    ca_native="yes"
  else
    ca_native="no"
  fi

  if test "x$want_ca" != "xno" && test "x$want_ca" != "xunset" &&
     test "x$want_capath" != "xno" && test "x$want_capath" != "xunset"; then
    dnl both given
    ca="$want_ca"
    capath="$want_capath"
  elif test "x$want_ca" != "xno" && test "x$want_ca" != "xunset"; then
    dnl --with-ca-bundle given
    ca="$want_ca"
    capath="no"
  elif test "x$want_capath" != "xno" && test "x$want_capath" != "xunset"; then
    dnl --with-ca-path given
    capath="$want_capath"
    ca="no"
  elif test "$ca_native" != "no"; then
    dnl native CA configured, do not look further
    ca="no"
    capath="no"
  else
    dnl First try auto-detecting a CA bundle, then a CA path.
    dnl Both auto-detections can be skipped by --without-ca-*
    ca="no"
    capath="no"
    if test "$cross_compiling" != "yes" &&
       test "$curl_cv_native_windows" != "yes"; then
      dnl NOT cross-compiling and...
      dnl neither of the --with-ca-* options are provided
      if test "x$want_ca" = "xunset"; then
        dnl the path we previously would have installed the curl CA bundle
        dnl to, and thus we now check for an already existing cert in that
        dnl place in case we find no other
        if test "x$prefix" != "xNONE"; then
          cac="${prefix}/share/curl/curl-ca-bundle.crt"
        else
          cac="$ac_default_prefix/share/curl/curl-ca-bundle.crt"
        fi

        for a in /etc/ssl/certs/ca-certificates.crt \
                 /etc/pki/tls/certs/ca-bundle.crt \
                 /usr/share/ssl/certs/ca-bundle.crt \
                 /usr/local/share/certs/ca-root-nss.crt \
                 /etc/ssl/cert.pem \
                 "$cac"; do
          if test -f "$a"; then
            ca="$a"
            break
          fi
        done
      fi
      AC_MSG_NOTICE([want $want_capath CA $ca])
      if test "x$want_capath" = "xunset"; then
        check_capath="/etc/ssl/certs"
      fi
    else
      dnl no option given and cross-compiling
      AC_MSG_WARN([skipped the ca-cert path detection when cross-compiling])
    fi
  fi

  if test "x$ca" = "xno" || test -f "$ca"; then
    ca_warning=""
  fi

  if test "x$capath" != "xno"; then
    check_capath="$capath"
  fi

  if test -n "$check_capath"; then
    for a in "$check_capath"; do
      if test -d "$a" && ls "$a"/[[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]].0 >/dev/null 2>/dev/null; then
        if test "x$capath" = "xno"; then
          capath="$a"
        fi
        capath_warning=""
        break
      fi
    done
  fi

  if test "x$capath" = "xno"; then
    capath_warning=""
  fi

  if test "x$ca" != "xno"; then
    CURL_CA_BUNDLE="$ca"
    AC_DEFINE_UNQUOTED(CURL_CA_BUNDLE, "$ca", [Location of default CA bundle])
    AC_SUBST(CURL_CA_BUNDLE)
    AC_MSG_RESULT([$ca])
  fi
  if test "x$capath" != "xno"; then
    CURL_CA_PATH="\"$capath\""
    AC_DEFINE_UNQUOTED(CURL_CA_PATH, "$capath", [Location of default CA path])
    AC_MSG_RESULT([$capath (capath)])
  fi
  if test "x$ca" = "xno" && test "x$capath" = "xno"; then
    AC_MSG_RESULT([no])
  fi

  AC_MSG_CHECKING([whether to use OpenSSL's built-in CA store])
  AC_ARG_WITH(ca-fallback,
AS_HELP_STRING([--with-ca-fallback], [Use OpenSSL's built-in CA store])
AS_HELP_STRING([--without-ca-fallback], [Do not use OpenSSL's built-in CA store]),
  [
    if test "x$with_ca_fallback" != "xyes" && test "x$with_ca_fallback" != "xno"; then
      AC_MSG_ERROR([--with-ca-fallback only allows yes or no as parameter])
    fi
  ],
  [ with_ca_fallback="no"])
  AC_MSG_RESULT([$with_ca_fallback])
  if test "x$with_ca_fallback" = "xyes"; then
    if test "$OPENSSL_ENABLED" != "1"; then
      AC_MSG_ERROR([--with-ca-fallback only works with OpenSSL])
    fi
    AC_DEFINE_UNQUOTED(CURL_CA_FALLBACK, 1, [define "1" to use OpenSSL's built-in CA store])
  fi
])


dnl CURL_CHECK_CA_EMBED
dnl -------------------------------------------------
dnl Check if a ca-bundle should be embedded

AC_DEFUN([CURL_CHECK_CA_EMBED], [

  AC_MSG_CHECKING([CA cert bundle path to embed in the curl tool])

  AC_ARG_WITH(ca-embed,
AS_HELP_STRING([--with-ca-embed=FILE],
  [Absolute path to a file containing CA certificates to embed in the curl tool (example: /etc/ca-bundle.crt)])
AS_HELP_STRING([--without-ca-embed], [Do not embed a default CA bundle in the curl tool]),
  [
    want_ca_embed="$withval"
    if test "x$want_ca_embed" = "xyes"; then
      AC_MSG_ERROR([--with-ca-embed=FILE requires a path to the CA bundle])
    fi
  ],
  [ want_ca_embed="unset" ])

  CURL_CA_EMBED=''
  if test "x$want_ca_embed" != "xno" && test "x$want_ca_embed" != "xunset" && test -f "$want_ca_embed"; then
    if test -n "$PERL"; then
      CURL_CA_EMBED="$want_ca_embed"
      AC_SUBST(CURL_CA_EMBED)
      AC_MSG_RESULT([$want_ca_embed])
    else
      AC_MSG_RESULT([no])
      AC_MSG_WARN([perl was not found. Cannot do CA embed.])
    fi
  else
    AC_MSG_RESULT([no])
  fi
])

dnl CURL_CHECK_WIN32_CRYPTO
dnl -------------------------------------------------
dnl Check if curl's Win32 crypto lib can be used

AC_DEFUN([CURL_CHECK_WIN32_CRYPTO], [
  AC_REQUIRE([CURL_CHECK_NATIVE_WINDOWS])
  AC_MSG_CHECKING([whether build target supports Win32 crypto API])
  curl_win32_crypto_api="no"
  if test "$curl_cv_native_windows" = "yes" && test "$curl_cv_winuwp" != "yes"; then
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
        #undef inline
        #ifndef WIN32_LEAN_AND_MEAN
        #define WIN32_LEAN_AND_MEAN
        #endif
        #include <windows.h>
        #include <wincrypt.h>
      ]],[[
        HCRYPTPROV hCryptProv;
        if(CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL,
                               CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
          CryptReleaseContext(hCryptProv, 0);
        }
      ]])
    ],[
      curl_win32_crypto_api="yes"
    ])
  fi
  case "$curl_win32_crypto_api" in
    yes)
      AC_MSG_RESULT([yes])
      AC_DEFINE_UNQUOTED(USE_WIN32_CRYPTO, 1,
        [Define to 1 if you are building a Windows target with crypto API support.])
      USE_WIN32_CRYPTO=1
      ;;
    *)
      AC_MSG_RESULT([no])
      ;;
  esac
])

dnl CURL_EXPORT_PCDIR ($pcdir, [$additive])
dnl ------------------------
dnl if $pcdir is not empty, set PKG_CONFIG_LIBDIR to $pcdir and export.
dnl if $additive is set, extend PKG_CONFIG_PATH instead, by prepending $pcdir
dnl to it, to ensure that system locations are still checked. This is
dnl necessary for modules that depend on modules residing there
dnl (e.g. gnutls.pc).
dnl
dnl we need this macro to limit/expand search locations to/with a custom
dnl configured one.
dnl

AC_DEFUN([CURL_EXPORT_PCDIR], [
  if test -n "$1"; then
    if test -n "$2"; then
      dnl honor system locations
      PKG_CONFIG_PATH="$1${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
      export PKG_CONFIG_PATH
    else
      dnl ignore and override system locations
      PKG_CONFIG_LIBDIR="$1"
      export PKG_CONFIG_LIBDIR
    fi
  fi
])

dnl CURL_TRACE_PCDIR ($module, [$pcdir], [$additive])
dnl ------------------------
dnl show pkg-config module lookup details, along with a detailed errors
dnl message in case of failure. Supports both pkg-config and pkgconf.
dnl

AC_DEFUN([CURL_TRACE_PCDIR], [
  dnl Example pkgconf line:
  dnl   libpkgconf/pkg.c:746 [pkgconf_pkg_t *pkgconf_pkg_try_specific_path(pkgconf_client_t *, [...]*)]:
  dnl     trying path: /usr/local/lib/pkgconfig for libngtcp2_crypto_gnutls
  dnl Rest of strings are for catching classic pkg-config lines.
  trc=`CURL_EXPORT_PCDIR([$2], [$3])
    if test -n "$PKG_CONFIG_LIBDIR"; then
      echo "PKG_CONFIG_LIBDIR: '$PKG_CONFIG_LIBDIR'"
    fi
    if test -n "$PKG_CONFIG_PATH"; then
      echo "PKG_CONFIG_PATH: '$PKG_CONFIG_PATH'"
    fi
    $PKGCONFIG --exists --debug $1 2>&1 | \
      $EGREP '(trying path:|Adding directory|Looking for|Scanning directory|Cannot open directory)' | \
      $SED 's/^.*trying path:/trying path:/'`
  msg=`CURL_EXPORT_PCDIR([$2], [$3])
    $PKGCONFIG --exists --print-errors $1 2>&1`
  if test -n "$msg"; then
    trc=`echo "$trc"; echo '==== error:'; echo "$msg"`
  fi
  AC_MSG_NOTICE([pkg-config --exists $1 trace:
---- begin
${trc}
---- end])
])

dnl CURL_CHECK_PKGCONFIG ($module, [$pcdir], [$additive])
dnl ------------------------
dnl search for the pkg-config tool. Set the PKGCONFIG variable to hold the
dnl path to it, or 'no' if not found/present.
dnl
dnl If pkg-config is present, check that it has info about the $module or
dnl return "no" anyway!
dnl
dnl Optionally PKG_CONFIG_LIBDIR may be given as $pcdir.
dnl

AC_DEFUN([CURL_CHECK_PKGCONFIG], [
  if test -n "$PKG_CONFIG"; then
    PKGCONFIG="$PKG_CONFIG"
  else
    AC_PATH_TOOL([PKGCONFIG], [pkg-config], [no],
      [$PATH:/usr/bin:/usr/local/bin])
  fi

  if test "$PKGCONFIG" != "no"; then
    AC_MSG_CHECKING([for $1 options with pkg-config])
    dnl ask pkg-config about $1
    itexists=`CURL_EXPORT_PCDIR([$2], [$3])
      $PKGCONFIG --exists $1 >/dev/null 2>&1 && echo 1`

    if test -z "$itexists"; then
      dnl pkg-config does not have info about the given module! set the
      dnl variable to 'no'
      AC_MSG_RESULT([no])
      if test -n "$CURL_TRACE_PKG_CONFIG$CURL_CI"; then
        CURL_TRACE_PCDIR([$1], [$2], [$3])
      fi
      PKGCONFIG="no"
    else
      AC_MSG_RESULT([found])
      if test -n "$CURL_TRACE_PKG_CONFIG"; then
        CURL_TRACE_PCDIR([$1], [$2], [$3])
      fi
    fi
  fi
])


dnl CURL_PREPARE_CONFIGUREHELP_PM
dnl -------------------------------------------------
dnl Prepare test harness configurehelp.pm module, defining and
dnl initializing some perl variables with values which are known
dnl when the configure script runs. For portability reasons, test
dnl harness needs information on how to run the C preprocessor.

AC_DEFUN([CURL_PREPARE_CONFIGUREHELP_PM], [
  AC_REQUIRE([AC_PROG_CPP])
  tmp_cpp=`eval echo "$ac_cpp" 2>/dev/null`
  if test -z "$tmp_cpp"; then
    tmp_cpp='cpp'
  fi
  AC_SUBST(CURL_CPP, $tmp_cpp)
])


dnl CURL_PREPARE_BUILDINFO
dnl -------------------------------------------------
dnl Save build info for test runner to pick up and log

AC_DEFUN([CURL_PREPARE_BUILDINFO], [
  curl_pflags=""
  if test "$curl_cv_apple" = "yes"; then
    curl_pflags="${curl_pflags} APPLE"
  fi
  case $host in
    *-*-*bsd*|*-*-aix*|*-*-hpux*|*-*-interix*|*-*-irix*|*-*-linux*|*-*-solaris*|*-*-sunos*|*-apple-*|*-*-cygwin*|*-*-msys*)
      curl_pflags="${curl_pflags} UNIX";;
  esac
  case $host in
    *-*-*bsd*)
      curl_pflags="${curl_pflags} BSD";;
  esac
  if test "$curl_cv_android" = "yes"; then
    curl_pflags="${curl_pflags} ANDROID"
    ANDROID_PLATFORM_LEVEL=`echo "$host_os" | $SED -ne 's/.*android\(@<:@0-9@:>@*\).*/\1/p'`
    if test -n "${ANDROID_PLATFORM_LEVEL}"; then
      curl_pflags="${curl_pflags}-${ANDROID_PLATFORM_LEVEL}"
    fi
  fi
  if test "$curl_cv_native_windows" = "yes"; then
    curl_pflags="${curl_pflags} WIN32"
  fi
  if test "$curl_cv_winuwp" = "yes"; then
    curl_pflags="${curl_pflags} UWP"
  fi
  case $host_os in
    cygwin*|msys*) curl_pflags="${curl_pflags} CYGWIN";;
  esac
  case $host_os in
    msdos*) curl_pflags="${curl_pflags} DOS";;
    amiga*) curl_pflags="${curl_pflags} AMIGA";;
  esac
  if test "$compiler_id" = "GNU_C"; then
    curl_pflags="${curl_pflags} GCC"
  fi
  if test "$compiler_id" = "APPLECLANG"; then
    curl_pflags="${curl_pflags} APPLE-CLANG"
  elif test "$compiler_id" = "CLANG"; then
    curl_pflags="${curl_pflags} LLVM-CLANG"
  fi
  case $host_os in
    mingw*) curl_pflags="${curl_pflags} MINGW";;
  esac
  if test "$cross_compiling" = "yes"; then
    curl_pflags="${curl_pflags} CROSS"
  fi
  squeeze curl_pflags
  curl_buildinfo="
buildinfo.configure.tool: configure
buildinfo.configure.args: $ac_configure_args
buildinfo.host: $build
buildinfo.host.cpu: $build_cpu
buildinfo.host.os: $build_os
buildinfo.target: $host
buildinfo.target.cpu: $host_cpu
buildinfo.target.os: $host_os
buildinfo.target.flags: $curl_pflags
buildinfo.compiler: $compiler_id
buildinfo.compiler.version: $compiler_ver
buildinfo.sysroot: $lt_sysroot"
])


dnl CURL_CPP_P
dnl
dnl Check if $cpp -P should be used for extract define values due to gcc 5
dnl splitting up strings and defines between line outputs. gcc by default
dnl (without -P) shows TEST EINVAL TEST as
dnl
dnl # 13 "conftest.c"
dnl TEST
dnl # 13 "conftest.c" 3 4
dnl     22
dnl # 13 "conftest.c"
dnl            TEST

AC_DEFUN([CURL_CPP_P], [
  AC_MSG_CHECKING([if cpp -P is needed])
  AC_EGREP_CPP([TEST.*TEST], [
 #include <errno.h>
TEST EINVAL TEST
  ], [cpp=no], [cpp=yes])
  AC_MSG_RESULT([$cpp])

  dnl we need cpp -P so check if it works then
  if test "$cpp" = "yes"; then
    AC_MSG_CHECKING([if cpp -P works])
    OLDCPPFLAGS=$CPPFLAGS
    CPPFLAGS="$CPPFLAGS -P"
    AC_EGREP_CPP([TEST.*TEST], [
 #include <errno.h>
TEST EINVAL TEST
    ], [cpp_p=yes], [cpp_p=no])
    AC_MSG_RESULT([$cpp_p])

    if test "$cpp_p" = "no"; then
      AC_MSG_WARN([failed to figure out cpp -P alternative])
      dnl without -P
      CPPPFLAG=""
    else
      dnl with -P
      CPPPFLAG="-P"
    fi
    dnl restore CPPFLAGS
    CPPFLAGS=$OLDCPPFLAGS
  else
    dnl without -P
    CPPPFLAG=""
  fi
])


dnl CURL_DARWIN_CFLAGS
dnl
dnl Set -Werror=partial-availability to detect possible breaking code
dnl with low deployment targets.
dnl

AC_DEFUN([CURL_DARWIN_CFLAGS], [
  old_CFLAGS=$CFLAGS
  CFLAGS="$CFLAGS -Werror=partial-availability"
  AC_MSG_CHECKING([whether $CC accepts -Werror=partial-availability])
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
    [AC_MSG_RESULT([yes])],
    [AC_MSG_RESULT([no])
    CFLAGS=$old_CFLAGS])
])


dnl CURL_SUPPORTS_BUILTIN_AVAILABLE
dnl
dnl Check to see if the compiler supports __builtin_available. This built-in
dnl compiler function first appeared in Apple LLVM 9.0.0. It is so new that, at
dnl the time this macro was written, the function was not yet documented. Its
dnl purpose is to return true if the code is running under a certain OS version
dnl or later.

AC_DEFUN([CURL_SUPPORTS_BUILTIN_AVAILABLE], [
  AC_MSG_CHECKING([to see if the compiler supports __builtin_available()])
  AC_COMPILE_IFELSE([
    AC_LANG_PROGRAM([[
    ]],[[
      if(__builtin_available(macOS 10.12, iOS 5.0, *)) {}
    ]])
  ],[
    AC_MSG_RESULT([yes])
    AC_DEFINE_UNQUOTED(HAVE_BUILTIN_AVAILABLE, 1,
      [Define to 1 if you have the __builtin_available function.])
  ],[
    AC_MSG_RESULT([no])
  ])
])