bash completion of makefile target

Question

Suppose I have a simple makefile like:

hello:
   echo \"hello world\"

bye:
   echo \"bye bye\"

Then in bash I want something like:

Answer 1

Here is a completion script that looks at the .PHONY: declaration.

_make_phony_words() {
  local opt_revert

  if [ -n "${BASH_VERSION:-}" ]; then
    shopt -q nullglob || {
      opt_revert=1 ; shopt -s nullglob ;
    }

  elif [ -n "${ZSH_VERSION:-}" ]; then
    [[ -o nullglob ]] || {
      opt_revert=1 ; setopt nullglob
    }
  fi

  for f in ./?akefile ./*.make ; do
    sed -nEe '/^.PHONY/ { s/^.PHONY:[ ]?// ; p ; } ' "$f" | tr ' ' $'\n' | sort -u
  done

  if [ -n "$opt_revert" ]; then

    [ -n "${ZSH_VERSION:-}" ] && unsetopt nullglob
    [ -n "${BASH_VERSION:-}" ] && shopt -u nullglob
  fi
  unset opt_revert

}

_make_phony_complete() {
  local cur="${COMP_WORDS[COMP_CWORD]}"

  COMPREPLY+=( $(compgen -W "$( _make_phony_words )" -- ${cur}) )

}
complete -F _make_phony_complete make