dnl Perform a check for a feature for GStreamer

 dnl Richard Boulton <richard-alsa@tartarus.org>

 dnl Thomas Vander Stichele <thomas@apestaart.org> added useful stuff

 dnl Last modification: 25/06/2001

 dnl GST_CHECK_FEATURE(FEATURE-NAME, FEATURE-DESCRIPTION,

 dnl                   DEPENDENT-PLUGINS, TEST-FOR-FEATURE,

 dnl                   DISABLE-BY-DEFAULT, ACTION-IF-USE, ACTION-IF-NOTUSE)

 dnl

 dnl This macro adds a command line argument to enable the user to enable

 dnl or disable a feature, and if the feature is enabled, performs a supplied

 dnl test to check if the feature is available.

 dnl

 dnl The test should define HAVE_<FEATURE-NAME> to "yes" or "no" depending

 dnl on whether the feature is available.

 dnl

 dnl The macro will set USE_<FEATURE-NAME> to "yes" or "no" depending on

 dnl whether the feature is to be used.

 dnl Thomas changed this, so that when USE_<FEATURE-NAME> was already set

 dnl to no, then it stays that way.

 dnl

 dnl The macro will call AM_CONDITIONAL(USE_<<FEATURE-NAME>, ...) to allow

 dnl the feature to control what is built in Makefile.ams.  If you want

 dnl additional actions resulting from the test, you can add them with the

 dnl ACTION-IF-USE and ACTION-IF-NOTUSE parameters.

 dnl 

 dnl FEATURE-NAME        is the name of the feature, and should be in

 dnl                     purely upper case characters.

 dnl FEATURE-DESCRIPTION is used to describe the feature in help text for

 dnl                     the command line argument.

 dnl DEPENDENT-PLUGINS   lists any plugins which depend on this feature.

 dnl TEST-FOR-FEATURE    is a test which sets HAVE_<FEATURE-NAME> to "yes"

 dnl                     or "no" depending on whether the feature is

 dnl                     available.

 dnl DISABLE-BY-DEFAULT  if "disabled", the feature is disabled by default,

 dnl                     if any other value, the feature is enabled by default.

 dnl ACTION-IF-USE       any extra actions to perform if the feature is to be

 dnl                     used.

 dnl ACTION-IF-NOTUSE    any extra actions to perform if the feature is not to

 dnl                     be used.

 dnl

 dnl

 dnl thomas :

 dnl we also added a history.  

 dnl GST_PLUGINS_YES will contain all plugins to be built

 dnl                 that were checked through GST_CHECK_FEATURE

 dnl GST_PLUGINS_NO will contain those that won't be built

 AC_DEFUN([GST_CHECK_FEATURE],

 AC_MSG_NOTICE(***)

 AC_MSG_NOTICE(*** checking plugin: [$3] ***)

 AC_MSG_NOTICE(***)

 [dnl

 builtin(define, [gst_endisable], ifelse($5, [disabled], [enable], [disable]))dnl

 dnl if it is set to NO, then don't even consider it for building

 NOUSE=

 if test "x$USE_[$1]" = "xno"; then

   NOUSE="yes"

 fi

 AC_ARG_ENABLE(translit([$1], A-Z, a-z),

   [  ]builtin(format, --%-26s gst_endisable %s, gst_endisable-translit([$1], A-Z, a-z), [$2]ifelse([$3],,,: [$3])),

   [ case "${enableval}" in

       yes) USE_[$1]=yes;;

       no) USE_[$1]=no;;

       *) AC_MSG_ERROR(bad value ${enableval} for --enable-translit([$1], A-Z, a-z)) ;;

     esac],

   [ USE_$1=]ifelse($5, [disabled], [no], [yes]))           dnl DEFAULT

 dnl *** set it back to no if it was preset to no

 if test "x$NOUSE" = "xyes"; then

   USE_[$1]="no"

   AC_MSG_WARN(*** $3 pre-configured not to be built)

 fi

 NOUSE=

 dnl *** If it's enabled

 if test x$USE_[$1] = xyes; then

   dnl save compile variables before the test

   gst_check_save_LIBS=$LIBS

   gst_check_save_LDFLAGS=$LDFLAGS

   gst_check_save_CFLAGS=$CFLAGS

   gst_check_save_CPPFLAGS=$CPPFLAGS

   gst_check_save_CXXFLAGS=$CXXFLAGS

   HAVE_[$1]=no

   dnl TEST_FOR_FEATURE

   $4

   LIBS=$gst_check_save_LIBS

   LDFLAGS=$gst_check_save_LDFLAGS

   CFLAGS=$gst_check_save_CFLAGS

   CPPFLAGS=$gst_check_save_CPPFLAGS

   CXXFLAGS=$gst_check_save_CXXFLAGS

   dnl If it isn't found, unset USE_[$1]

   if test x$HAVE_[$1] = xno; then

     USE_[$1]=no

   fi

 fi

 dnl *** Warn if it's disabled or not found

 if test x$USE_[$1] = xyes; then

   ifelse([$6], , :, [$6])

   if test "x$3" != "x"; then

     GST_PLUGINS_YES="\t[$3]\n$GST_PLUGINS_YES"

   fi

   AC_DEFINE(HAVE_[$1], , [support for features: $3])

 else

   ifelse([$3], , :, [AC_MSG_NOTICE(*** These plugins will not be built: [$3])])

   if test "x$3" != "x"; then

     GST_PLUGINS_NO="\t[$3]\n$GST_PLUGINS_NO"

   fi

   ifelse([$7], , :, [$7])

 fi

 dnl *** Define the conditional as appropriate

 AM_CONDITIONAL(USE_[$1], test x$USE_[$1] = xyes)

 ])

 dnl Use a -config program which accepts --cflags and --libs parameters

 dnl to set *_CFLAGS and *_LIBS and check existence of a feature.

 dnl Richard Boulton <richard-alsa@tartarus.org>

 dnl Last modification: 26/06/2001

 dnl GST_CHECK_CONFIGPROG(FEATURE-NAME, CONFIG-PROG-FILENAME, MODULES)

 dnl

 dnl This check was written for GStreamer: it should be renamed and checked

 dnl for portability if you decide to use it elsewhere.

 dnl

 AC_DEFUN([GST_CHECK_CONFIGPROG],

 [

   AC_PATH_PROG([$1]_CONFIG, [$2], no)

   if test x$[$1]_CONFIG = xno; then

     [$1]_LIBS=

     [$1]_CFLAGS=

     HAVE_[$1]=no

   else

     if [$2] --plugin-libs [$3] &> /dev/null; then

       [$1]_LIBS=`[$2] --plugin-libs [$3]`

     else

       [$1]_LIBS=`[$2] --libs [$3]`

     fi

     [$1]_CFLAGS=`[$2] --cflags [$3]`

     HAVE_[$1]=yes

   fi

   AC_SUBST([$1]_LIBS)

   AC_SUBST([$1]_CFLAGS)

 ])

 dnl Use AC_CHECK_LIB and AC_CHECK_HEADER to do both tests at once

 dnl sets HAVE_module if we have it

 dnl Richard Boulton <richard-alsa@tartarus.org>

 dnl Last modification: 26/06/2001

 dnl GST_CHECK_LIBHEADER(FEATURE-NAME, LIB NAME, LIB FUNCTION, EXTRA LD FLAGS, 

 dnl                     HEADER NAME, ACTION-IF-FOUND, ACTION-IF-NOT-FOUND)

 dnl

 dnl This check was written for GStreamer: it should be renamed and checked

 dnl for portability if you decide to use it elsewhere.

 dnl

 AC_DEFUN([GST_CHECK_LIBHEADER],

 [

   AC_CHECK_LIB([$2], [$3], HAVE_[$1]=yes, HAVE_[$1]=no,[$4])

   if test "x$HAVE_[$1]" = "xyes"; then

     AC_CHECK_HEADER([$5], :, HAVE_[$1]=no)

     if test "x$HAVE_[$1]" = "xyes"; then

       dnl execute what needs to be

       ifelse([$6], , :, [$6])

     else

       ifelse([$7], , :, [$7])

     fi

   else

     ifelse([$7], , :, [$7])

   fi

   AC_SUBST(HAVE_[$1])

 ]

 )

 dnl 2004-02-14 Thomas - changed to get set properly and use proper output

 dnl 2003-06-27 Benjamin Otte - changed to make this work with gstconfig.h

 dnl

 dnl Add a subsystem --disable flag and all the necessary symbols and substitions

 dnl

 dnl GST_CHECK_SUBSYSTEM_DISABLE(SYSNAME, [subsystem name])

 dnl

 AC_DEFUN([GST_CHECK_SUBSYSTEM_DISABLE],

 [

   dnl this define will replace each literal subsys_def occurrence with

   dnl the lowercase hyphen-separated subsystem

   dnl e.g. if $1 is GST_DEBUG then subsys_def will be a macro with gst-debug

   define([subsys_def],translit([$1], _A-Z, -a-z))

   AC_ARG_ENABLE(subsys_def, 

     AC_HELP_STRING(--disable-subsys_def, [disable $2]),

     [

       case "${enableval}" in

         yes) GST_DISABLE_[$1]=no ;;

         no) GST_DISABLE_[$1]=yes ;;

         *) AC_MSG_ERROR([bad value ${enableval} for --enable-subsys_def]) ;;

        esac

     ],

     [GST_DISABLE_[$1]=no]) dnl Default value

   if test x$GST_DISABLE_[$1] = xyes; then

     AC_MSG_NOTICE([disabled subsystem [$2]])

     GST_DISABLE_[$1]_DEFINE="#define GST_DISABLE_$1 1" 

   else

     GST_DISABLE_[$1]_DEFINE="/* #undef GST_DISABLE_$1 */"

   fi

   AC_SUBST(GST_DISABLE_[$1]_DEFINE)

   undefine([subsys_def])

 ])