#!/bin/sh

# This wrapper takes the arguments: <ar> <operation> <archive> <files...>
# <ar> can be any ar implementation.
# <operations>, <archive> and <files...> are the normal arguments to <ar>.
#
# OS X's ar implementation has the problem, that it refuses to create empty archives.
# This wrapper will copy a provided empty .a file to <archive> if it was told to.

# If <operations> contains "r", and there are no <files...> given.
if [ "${2#*r}" != "$2" ] && [ "$#" -eq 3 ]; then
    # If <archive> exists, do nothing, otherwise copy an empty archive.
    [ -e "$3" ] || cp "${0%ar-wrapper}/empty.a" "$3"
else
    # Otherwise act like this wrapper was not present.
    "$@"
fi

# Return the exit code of the last invocation ("[", "cp", or <ar>).
exit $?