# gcc(1) completion                                        -*- shell-script -*-

_gcc()
{
    local cur prev prev2 words cword argument prefix prefix_length
    _init_completion || return

    # Test that GCC is recent enough and if not fallback to
    # parsing of --completion option.
    if ! $1 --completion=" " 2>/dev/null; then
        if [[ $cur == -* ]]; then
            local cc=$($1 -print-prog-name=cc1 2>/dev/null)
            [[ $cc ]] || return
            COMPREPLY=($(compgen -W "$($cc --help 2>/dev/null | tr '\t' ' ' |
                command sed -e '/^  *-/!d' -e 's/ *-\([^][ <>]*\).*/-\1/')" \
                -- "$cur"))
            [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
        else
            _filedir
        fi
        return
    fi

    # extract also for situations like: -fsanitize=add
    if ((cword > 2)); then
        prev2="${COMP_WORDS[cword - 2]}"
    fi

    # sample: -fsan
    if [[ $cur == -* ]]; then
        argument=$cur
        prefix=""
    # sample: -fsanitize=
    elif [[ $cur == "=" && $prev == -* ]]; then
        argument=$prev$cur
        prefix=$prev$cur
    # sample: -fsanitize=add
    elif [[ $prev == "=" && $prev2 == -* ]]; then
        argument=$prev2$prev$cur
        prefix=$prev2$prev
    # sample: --param lto-
    elif [[ $prev == --param ]]; then
        argument="$prev $cur"
        prefix="$prev "
    fi

    if [[ ! -v argument ]]; then
        _filedir
    else
        # In situation like '-fsanitize=add' $cur is equal to last token.
        # Thus we need to strip the beginning of suggested option.
        prefix_length=$((${#prefix} + 1))
        local flags=$($1 --completion="$argument" | cut -c $prefix_length-)
        [[ ${flags} == "=*" ]] && compopt -o nospace 2>/dev/null
        COMPREPLY=($(compgen -W "$flags" -- ""))
    fi
} &&
    complete -F _gcc gcc{,-5,-6,-7,-8} g++{,-5,-6,-7,-8} g77 g95 \
        gccgo{,-5,-6,-7,-8} gcj gfortran{,-5,-6,-7,-8} gpc &&
    {
        cc --version 2>/dev/null | command grep -q GCC ||
            [[ $(_realcommand cc) == *gcc* ]] &&
            complete -F _gcc cc || complete -F _minimal cc
        c++ --version 2>/dev/null | command grep -q GCC ||
            [[ $(_realcommand c++) == *g++* ]] &&
            complete -F _gcc c++ || complete -F _minimal c++
        f77 --version 2>/dev/null | command grep -q GCC ||
            [[ $(_realcommand f77) == *gfortran* ]] &&
            complete -F _gcc f77 || complete -F _minimal f77
        f95 --version 2>/dev/null | command grep -q GCC ||
            [[ $(_realcommand f95) == *gfortran* ]] &&
            complete -F _gcc f95 || complete -F _minimal f95
    }

# ex: filetype=sh