#!/bin/sh

#
# feature-remove: removes features by defining special variables
# indicating particular code segments are unneeded.  This is done by
# examining the list of provided features and defining a REMOVE
# equivalent if no other module required it.
#
# Arguments:
#   feature-remove mainheader.h globalheader.h THEREST
#
# Where THEREST are a list of features to remove (default) or add.
#
#   --add switches to "adding" and --remove switches back.
#
# E.G.
#   feature-remove mainheader.h globalheader.h oid_stash --add container_null
#
CP=cp

featureheader="$1"
featureheaderin="$1.in"
featureheaderglobal="$2"
shift
shift

argumenttype="--remove"
removethese=""
addthese=""

while test "x$1" != "x" ; do
    uc=`echo $1 | tr a-z A-Z`
    case $1 in
	--*)
	    argumenttype="$1"
	    ;;

	*)
	    if test "x$argumenttype" = "x--remove" ; then
		removethese="$removethese $uc"
	    else
		addthese="$addthese $uc"
	    fi
	    ;;
    esac
    shift
done

echo "" > $featureheader
echo "/* The following defines features that Net-SNMP HAS or has REMOVEd */" >> $featureheader

haslist=" "

for i in `grep NETSNMP_FEATURE_PROVIDE_ $featureheaderin | sed 's/.*FEATURE_PROVIDE_//;s/ .*//'` ; do
    #
    # If we were specifically asked to include it, then do so
    #
    if echo " $addthese " | grep " ${i} " > /dev/null ; then
       # The user required it ; report we're using it
	echo "#define NETSNMP_FEATURE_HAS_$i 1" >> $featureheader
	haslist="${haslist}${i} "

    #
    # check to see if something requried it
    #
    elif grep "NETSNMP_FEATURE_REQUIRE_${i} " $featureheaderglobal > /dev/null ; then
	# if so, make sure we weren't asked to remove it
       	if echo  " $removethese "| grep " $i " > /dev/null ; then
       	   # Uh oh; they specifically wanted it removed but it was required
	   echo "Feature Error:"
       	   echo " Feature '$i' was asked to be removed but something required it"
       	   echo " See the $featureheaderglobal file for dependency details"
	   echo ""
           rm -f $featureheader
       	   exit 1
       	fi

       	# something required it ; report we're using it
       	echo "#define NETSNMP_FEATURE_HAS_$i 1" >> $featureheader
	haslist="${haslist}${i} "

    #
    # check to see if something "wanted" it
    #
    elif grep "NETSNMP_FEATURE_WANT_${i} " $featureheaderglobal > /dev/null ; then
	   # nothing required it, but something "wanted" it

	   # check to make sure we weren't asked to exclude it
           if echo " $removethese " | grep " $i " > /dev/null ; then
               # we were specifically asked *not* to use this feature
               echo "#define NETSNMP_FEATURE_REMOVE_$i 1" >> $featureheader
           else
	       # something wanted it, so we'll include it
	       echo "#define NETSNMP_FEATURE_HAS_$i 1" >> $featureheader
	       haslist="${haslist}${i} "
           fi


    #
    # check to see if something required a parent
    #
    elif egrep NETSNMP_FEATURE_${i}_CHILD_OF $featureheaderglobal > /dev/null ; then
	parentnames=`egrep NETSNMP_FEATURE_${i}_CHILD_OF $featureheaderglobal | sed 's/.*CHILD_OF_//;s/ .*//;'`

	foundone=0
	for parentname in $parentnames ; do
   	    # if the parent was desired, then we are too:
	    
	    if test $foundone = 0 ; then
		if egrep "NETSNMP_FEATURE_HAS_${parentname} " $featureheader > /dev/null ; then
       		    echo "#define NETSNMP_FEATURE_HAS_$i 1" >> $featureheader
		    haslist="${haslist}${i} "
		    foundone=1
		fi
	    fi
        done
	if test $foundone = 0 ; then
    	    echo "#define NETSNMP_FEATURE_REMOVE_$i 1" >> $featureheader
	fi

    #
    # no one required or wanted it -- it is safe to remove it
    #
    else
    	 echo "#define NETSNMP_FEATURE_REMOVE_$i 1" >> $featureheader
    fi
done