Re: /lib/cpp not found in c-mode

[Nick Roberts]

 > >> On my OSX (10.3.8) it is in /usr/bin/cpp.
 > >
 > > In that case, c-macro-preprocessor is set to "/lib/cpp -C" and 
 > > c-macro-expand
 > > doesn't work on OSX?
 > 
 > If c-macro-preprocessor is a recent variable I can't check because 
 > Emacs does not currently compile on Mac OSX 10.3.  My (a bit old) CVS 
 > compile does not seem to have it.

c-macro-expand and c-macro-preprocessor have been around for quite a
while. c-macro-expand is an interactive autoloaded Lisp function in cmacexp.el
that can be invoked in C mode with C-c C-e or from the menu-bar.  Apparently
this file is not part of cc-mode so perhaps its not being maintained.
c-macro-expand seems quite useful so I'm kind of surprised that, as a C
specialist, you're don't use it/not familiar with it.

 > But c-macro-expand does not work:

If we added the line below to c-macro-preprocessor would it work then for Mac
OSX?

Nick


(defcustom c-macro-preprocessor
  ;; Cannot rely on standard directory on MS-DOS to find CPP.  In
  ;; fact, cannot rely on having cpp.exe, either, in latest GCC
  ;; versions.
  (cond ((eq system-type 'ms-dos) "gcc -E -C -o - -")
        ;; Solaris has it in an unusual place.
        ((and (string-match "^[^-]*-[^-]*-\\(solaris\\|sunos5\\)"
                            system-configuration)
              (file-exists-p "/opt/SUNWspro/SC3.0.1/bin/acomp"))
         "/opt/SUNWspro/SC3.0.1/bin/acomp -C -E")
        ((file-exists-p "/usr/ccs/lib/cpp") "/usr/ccs/lib/cpp -C")
+       ((eq system-type 'darwin) "cpp -C")
        (t "/lib/cpp -C"))
  "The preprocessor used by the cmacexp package.

If you change this, be sure to preserve the `-C' (don't strip comments)
option, or to set an equivalent one."
  :type 'string
  :group 'c-macro)