curl/docs/libcurl/libcurl.m4

#***************************************************************************
#                                  _   _ ____  _
#  Project                     ___| | | |  _ \| |
#                             / __| | | | |_) | |
#                            | (__| |_| |  _ <| |___
#                             \___|\___/|_| \_\_____|
#
# Copyright (C) David Shaw <dshaw@jabberwocky.com>
#
# 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
#
###########################################################################
# LIBCURL_CHECK_CONFIG ([DEFAULT-ACTION], [MINIMUM-VERSION],
#                       [ACTION-IF-YES], [ACTION-IF-NO])
# ----------------------------------------------------------
#      David Shaw <dshaw@jabberwocky.com>   May-09-2006
#
# Checks for libcurl.  DEFAULT-ACTION is the string yes or no to
# specify whether to default to --with-libcurl or --without-libcurl.
# If not supplied, DEFAULT-ACTION is yes.  MINIMUM-VERSION is the
# minimum version of libcurl to accept.  Pass the version as a regular
# version number like 7.10.1. If not supplied, any version is
# accepted.  ACTION-IF-YES is a list of shell commands to run if
# libcurl was successfully found and passed the various tests.
# ACTION-IF-NO is a list of shell commands that are run otherwise.
# Note that using --without-libcurl does run ACTION-IF-NO.
#
# This macro #defines HAVE_LIBCURL if a working libcurl setup is
# found, and sets @LIBCURL@ and @LIBCURL_CPPFLAGS@ to the necessary
# values.  Other useful defines are LIBCURL_FEATURE_xxx where xxx are
# the various features supported by libcurl, and LIBCURL_PROTOCOL_yyy
# where yyy are the various protocols supported by libcurl.  Both xxx
# and yyy are capitalized.  See the list of AH_TEMPLATEs at the top of
# the macro for the complete list of possible defines.  Shell
# variables $libcurl_feature_xxx and $libcurl_protocol_yyy are also
# defined to 'yes' for those features and protocols that were found.
# Note that xxx and yyy keep the same capitalization as in the
# curl-config list (e.g. it's "HTTP" and not "http").
#
# Users may override the detected values by doing something like:
# LIBCURL="-lcurl" LIBCURL_CPPFLAGS="-I/usr/myinclude" ./configure
#
# For the sake of sanity, this macro assumes that any libcurl that is found is
# after version 7.7.2, the first version that included the curl-config script.
# Note that it is important for people packaging binary versions of libcurl to
# include this script!  Without curl-config, we can only guess what protocols
# are available, or use curl_version_info to figure it out at runtime.

AC_DEFUN([LIBCURL_CHECK_CONFIG],
[
  AH_TEMPLATE([LIBCURL_FEATURE_SSL],[Defined if libcurl supports SSL])
  AH_TEMPLATE([LIBCURL_FEATURE_KRB4],[Defined if libcurl supports KRB4])
  AH_TEMPLATE([LIBCURL_FEATURE_IPV6],[Defined if libcurl supports IPv6])
  AH_TEMPLATE([LIBCURL_FEATURE_LIBZ],[Defined if libcurl supports libz])
  AH_TEMPLATE([LIBCURL_FEATURE_ASYNCHDNS],[Defined if libcurl supports AsynchDNS])
  AH_TEMPLATE([LIBCURL_FEATURE_IDN],[Defined if libcurl supports IDN])
  AH_TEMPLATE([LIBCURL_FEATURE_SSPI],[Defined if libcurl supports SSPI])
  AH_TEMPLATE([LIBCURL_FEATURE_NTLM],[Defined if libcurl supports NTLM])

  AH_TEMPLATE([LIBCURL_PROTOCOL_HTTP],[Defined if libcurl supports HTTP])
  AH_TEMPLATE([LIBCURL_PROTOCOL_HTTPS],[Defined if libcurl supports HTTPS])
  AH_TEMPLATE([LIBCURL_PROTOCOL_FTP],[Defined if libcurl supports FTP])
  AH_TEMPLATE([LIBCURL_PROTOCOL_FTPS],[Defined if libcurl supports FTPS])
  AH_TEMPLATE([LIBCURL_PROTOCOL_FILE],[Defined if libcurl supports FILE])
  AH_TEMPLATE([LIBCURL_PROTOCOL_TELNET],[Defined if libcurl supports TELNET])
  AH_TEMPLATE([LIBCURL_PROTOCOL_LDAP],[Defined if libcurl supports LDAP])
  AH_TEMPLATE([LIBCURL_PROTOCOL_DICT],[Defined if libcurl supports DICT])
  AH_TEMPLATE([LIBCURL_PROTOCOL_TFTP],[Defined if libcurl supports TFTP])
  AH_TEMPLATE([LIBCURL_PROTOCOL_RTSP],[Defined if libcurl supports RTSP])
  AH_TEMPLATE([LIBCURL_PROTOCOL_POP3],[Defined if libcurl supports POP3])
  AH_TEMPLATE([LIBCURL_PROTOCOL_IMAP],[Defined if libcurl supports IMAP])
  AH_TEMPLATE([LIBCURL_PROTOCOL_SMTP],[Defined if libcurl supports SMTP])

  AC_ARG_WITH(libcurl,
     AS_HELP_STRING([--with-libcurl=PREFIX],[look for the curl library in PREFIX/lib and headers in PREFIX/include]),
     [_libcurl_with=$withval],[_libcurl_with=ifelse([$1],,[yes],[$1])])

  if test "$_libcurl_with" != "no" ; then

     AC_PROG_AWK

     _libcurl_version_parse="eval $AWK '{split(\$NF,A,\".\"); X=256*256*A[[1]]+256*A[[2]]+A[[3]]; print X;}'"

     _libcurl_try_link=yes

     if test -d "$_libcurl_with" ; then
        LIBCURL_CPPFLAGS="-I$withval/include"
        _libcurl_ldflags="-L$withval/lib"
        AC_PATH_PROG([_libcurl_config],[curl-config],[],
                     ["$withval/bin"])
     else
        AC_PATH_PROG([_libcurl_config],[curl-config],[],[$PATH])
     fi

     if test x$_libcurl_config != "x" ; then
        AC_CACHE_CHECK([for the version of libcurl],
           [libcurl_cv_lib_curl_version],
           [libcurl_cv_lib_curl_version=`$_libcurl_config --version | $AWK '{print $[]2}'`])

        _libcurl_version=`echo $libcurl_cv_lib_curl_version | $_libcurl_version_parse`
        _libcurl_wanted=`echo ifelse([$2],,[0],[$2]) | $_libcurl_version_parse`

        if test $_libcurl_wanted -gt 0 ; then
           AC_CACHE_CHECK([for libcurl >= version $2],
              [libcurl_cv_lib_version_ok],
              [
              if test $_libcurl_version -ge $_libcurl_wanted ; then
                 libcurl_cv_lib_version_ok=yes
              else
                 libcurl_cv_lib_version_ok=no
              fi
              ])
        fi

        if test $_libcurl_wanted -eq 0 || test x$libcurl_cv_lib_version_ok = xyes ; then
           if test x"$LIBCURL_CPPFLAGS" = "x" ; then
              LIBCURL_CPPFLAGS=`$_libcurl_config --cflags`
           fi
           if test x"$LIBCURL" = "x" ; then
              LIBCURL=`$_libcurl_config --libs`

              # This is so silly, but Apple actually has a bug in their
              # curl-config script.  Fixed in Tiger, but there are still
              # lots of Panther installs around.
              case "${host}" in
                 powerpc-apple-darwin7*)
                    LIBCURL=`echo $LIBCURL | sed -e 's|-arch i386||g'`
                 ;;
              esac
           fi

           # All curl-config scripts support --feature
           _libcurl_features=`$_libcurl_config --feature`

           # Is it modern enough to have --protocols? (7.12.4)
           if test $_libcurl_version -ge 461828 ; then
              _libcurl_protocols=`$_libcurl_config --protocols`
           fi
        else
           _libcurl_try_link=no
        fi

        unset _libcurl_wanted
     fi

     if test $_libcurl_try_link = yes ; then

        # we did not find curl-config, so let's see if the user-supplied
        # link line (or failing that, "-lcurl") is enough.
        LIBCURL=${LIBCURL-"$_libcurl_ldflags -lcurl"}

        AC_CACHE_CHECK([whether libcurl is usable],
           [libcurl_cv_lib_curl_usable],
           [
           _libcurl_save_cppflags=$CPPFLAGS
           CPPFLAGS="$LIBCURL_CPPFLAGS $CPPFLAGS"
           _libcurl_save_libs=$LIBS
           LIBS="$LIBCURL $LIBS"

           AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <curl/curl.h>]],[[
/* Try to use a few common options to force a failure if we are
   missing symbols or cannot link. */
int x;
curl_easy_setopt(NULL,CURLOPT_URL,NULL);
x=CURL_ERROR_SIZE;
x=CURLOPT_WRITEFUNCTION;
x=CURLOPT_WRITEDATA;
x=CURLOPT_ERRORBUFFER;
x=CURLOPT_STDERR;
x=CURLOPT_VERBOSE;
if (x) {;}
]])],libcurl_cv_lib_curl_usable=yes,libcurl_cv_lib_curl_usable=no)

           CPPFLAGS=$_libcurl_save_cppflags
           LIBS=$_libcurl_save_libs
           unset _libcurl_save_cppflags
           unset _libcurl_save_libs
           ])

        if test $libcurl_cv_lib_curl_usable = yes ; then

           # Does curl_free() exist in this version of libcurl?
           # If not, fake it with free()

           _libcurl_save_cppflags=$CPPFLAGS
           CPPFLAGS="$CPPFLAGS $LIBCURL_CPPFLAGS"
           _libcurl_save_libs=$LIBS
           LIBS="$LIBS $LIBCURL"

           AC_CHECK_DECL([curl_free],[],
              [AC_DEFINE([curl_free],[free],
                [Define curl_free() as free() if our version of curl lacks curl_free.])],
              [[#include <curl/curl.h>]])

           CPPFLAGS=$_libcurl_save_cppflags
           LIBS=$_libcurl_save_libs
           unset _libcurl_save_cppflags
           unset _libcurl_save_libs

           AC_DEFINE(HAVE_LIBCURL,1,
             [Define to 1 if you have a functional curl library.])
           AC_SUBST(LIBCURL_CPPFLAGS)
           AC_SUBST(LIBCURL)

           for _libcurl_feature in $_libcurl_features ; do
              AC_DEFINE_UNQUOTED(AS_TR_CPP(libcurl_feature_$_libcurl_feature),[1])
              eval AS_TR_SH(libcurl_feature_$_libcurl_feature)=yes
           done

           if test "x$_libcurl_protocols" = "x" ; then

              # We do not have --protocols, so just assume that all
              # protocols are available
              _libcurl_protocols="HTTP FTP FILE TELNET LDAP DICT TFTP"

              if test x$libcurl_feature_SSL = xyes ; then
                 _libcurl_protocols="$_libcurl_protocols HTTPS"

                 # FTPS was not standards-compliant until version
                 # 7.11.0 (0x070b00 == 461568)
                 if test $_libcurl_version -ge 461568; then
                    _libcurl_protocols="$_libcurl_protocols FTPS"
                 fi
              fi

              # RTSP, IMAP, POP3 and SMTP were added in
              # 7.20.0 (0x071400 == 463872)
              if test $_libcurl_version -ge 463872; then
                 _libcurl_protocols="$_libcurl_protocols RTSP IMAP POP3 SMTP"
              fi
           fi

           for _libcurl_protocol in $_libcurl_protocols ; do
              AC_DEFINE_UNQUOTED(AS_TR_CPP(libcurl_protocol_$_libcurl_protocol),[1])
              eval AS_TR_SH(libcurl_protocol_$_libcurl_protocol)=yes
           done
        else
           unset LIBCURL
           unset LIBCURL_CPPFLAGS
        fi
     fi

     unset _libcurl_try_link
     unset _libcurl_version_parse
     unset _libcurl_config
     unset _libcurl_feature
     unset _libcurl_features
     unset _libcurl_protocol
     unset _libcurl_protocols
     unset _libcurl_version
     unset _libcurl_ldflags
  fi

  if test x$_libcurl_with = xno || test x$libcurl_cv_lib_curl_usable != xyes ; then
     # This is the IF-NO path
     ifelse([$4],,:,[$4])
  else
     # This is the IF-YES path
     ifelse([$3],,:,[$3])
  fi

  unset _libcurl_with
])