problem with hardcode_libdir_flag_spec

[Werner LEMBERG]

[libtool 2.4.2]

Folks,


let's assume that someone is doing

  AC_SUBST([libdir])
  AC_SUBST([wl])
  AC_SUBST([hardcode_libdir_flag_spec])

and later tries to say

  libdir = @libdir@
  wl = @wl@
  hardcode_libdir_flag_spec = @hardcode_libdir_flag_spec@

within a Makefile, as can be done with other such variables.  [The
idea is to construct a proper `-R' linker argument for a `--libs'
option of a `foo-config' file generated at compile time, but this is a
different issue.]

However, this causes a very unpleasant surprise since the above
snippet gets converted to

  libdir = /foo/bar
  wl = -Wl,
  hardcode_libdir_flag_spec = '${wl}-rpath ${wl}$libdir'

Note the `$libdir' string which gets interpreted as variable `$l'
followed by `ibdir' within a Makefile...

Now my questions.

  . Is it a bug?  It should be trivial IMHO to use ${libdir} instead
    to avoid incorrect Makefile variable expansion.  I can imagine
    that other variables (even in autoconf or automake) are similarly
    affected.

  . Is it correct usage?  I mean, is there a list of autotools
    variables which must not be used within a Makefile (after
    AC_SUBST)?

  . How can I circumvent the problem with the current libtool version?


  Werner