curl/docs/libcurl/libcurl.m4

# LIBCURL_CHECK_CONFIG ([DEFAULT-ACTION], [MINIMUM-VERSION],
#                       [ACTION-IF-YES], [ACTION-IF-NO])
# ----------------------------------------------------------
#      David Shaw <dshaw@jabberwocky.com>   Jan-23-2005
#
# 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 very important for people
# packaging binary versions of libcurl to include this script!
# Without curl-config, we can only make educated guesses as to what
# protocols are available.  Specifically, we assume that all of HTTP,
# FTP, GOPHER, FILE, TELNET, LDAP, and DICT exist, and (if SSL exists)
# HTTPS is present.  All of these protocols existed when libcurl was
# first created in version 7, so this is a safe assumption.  If the
# version is 7.11.0 or later, FTPS is assumed to be present as well.
# FTPS existed before then, but was not yet fully standards compliant.

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_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_GOPHER],[Defined if libcurl supports GOPHER])
  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])

  AC_ARG_WITH(libcurl,
     AC_HELP_STRING([--with-libcurl=DIR],[look for the curl library in DIR]),
     [_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 "$_libcurl_with" ; then
        CPPFLAGS="${CPPFLAGS} -I$withval/include"
        LDFLAGS="${LDFLAGS} -L$withval/lib"
     fi

     AC_PATH_PROG([_libcurl_config],[curl-config])

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

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

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

           CPPFLAGS=$_libcurl_save_cppflags
           LDFLAGS=$_libcurl_save_ldflags
           unset _libcurl_save_cppflags
           unset _libcurl_save_ldflags
           ])

        if test $libcurl_cv_lib_curl_usable = yes ; then
           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 don't have --protocols, so just assume that all
	      # protocols are available
	      _libcurl_protocols="HTTP FTP GOPHER FILE TELNET LDAP DICT"

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

		 # FTPS wasn't standards-compliant until version
		 # 7.11.0
		 if test $_libcurl_version -ge 461568; then
		    _libcurl_protocols="$_libcurl_protocols FTPS"
		 fi
	      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
        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
  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
])dnl