# A bunch of shell functions that help finding unnecessary includes.
# Relies on appropriate versions of etags, grep, tr, awk and maybe bash.
#
# To use:
#   $ . util/include.sh
#   $ checkall
# Tries to list all names defined in the header file $1.
# Indented names are assumed to be members that don't need to be checked,
# which will fail for indented declarations with #ifdefs.
names () 
{ 
    b=$(basename $1 .h);
    etags --declarations -D $1 -o - | grep '^[#a-z]' | grep -v '^'$b'\.h' \
        | tr '\177' '\t' | awk '{ print $(NF-1) }'
}
# lists possible uses in $2 of names defined in $1
mightuse () 
{ 
    for n in $(names $1);
    do
        if grep -F $n $2; then
            return 0;
        fi;
    done;
    return 1
}
# checks whether source file $2 #include's $1
includes () 
{ 
    grep '#include "'$1'"' $2
}
# echo arguments if $2 includes $1 put shouldn't
check ()
{
    if includes $1 $2 > /dev/null && ! mightuse $1 $2 > /dev/null; then
        echo $hdr $src;
    fi
}
# run check on all pairs -- should really cache the result of "names"
checkall ()
{
    for hdr in *.h; do
        if [ $hdr = AppHdr.h ]; then
            continue;
        fi
        for src in *.cc; do
            check $hdr $src
        done
    done
}