[Axiom-developer] RE: Cannot Rename The File Erlib To NRLIB

[Page, Bill]

On Wednesday, August 30, 2006 5:13 AM I wrote:
> Camm Maguire wrote:
> > 
> > I though you had problems renaming, not deleting?  I have
> > not done anything here (yet).
> > 
> 
> You are right. So in addition to your change to
> 'gcl-2.6.8pre/o/unixfsys.c' in delete_file:
> 
>         if (unlink(filename) < 0 && rmdir(filename) < 0)
>                 FEerror("Cannot delete the file ~S: ~s.", 2,
>                   path, make_simple_string(strerror(errno)));
> 
> and I added the following to rename_file:
> 
> #ifdef HAVE_RENAME
>         /* Make sure we can rename */
>         if (unlink(newfilename) < 0) rmdir(newfilename);
>         if (rename(filename, newfilename) < 0)
>                 FEerror("Cannot rename the file ~S to ~S.",
>                         2, vs_base[0], vs_base[1]);
> #else
>         sprintf(command, "mv %s %s", filename, newfilename);
>         system(command);
> #endif
> ...
> 
> I am testing the build now.
>

My tests of re-compiling a SPAD function still failed. :-(

Unfortunately my patch to rename_file is not sufficient for Axiom.
Axiom really does seem to expect that rename is as destructive
as the 'mv' shell command. But the semantics of 'rename' is
different:

http://www.gnu.org/software/libc/manual/html_node/Renaming-Files.html

int rename (const char *oldname, const char *newname)

"If oldname is a directory, then either newname must not exist
or it must name a directory that is empty. In the latter case,
the existing directory named newname is deleted first."

It seems that to simulate the behaviour of 'mv' with the Gnu C
library one must write a simple recursive routine to hit all of
the files and subdirectories of a given directory, etc. etc.

---------------

But wait a minute! Does hacking away at GCL really make any
sense? Let's take a look at exactly what Axiom is doing with
this ... dig dig dig ... Aha:

    src/interp/nlib.lisp.pamphlet

Ok, here is the offensive coding in Axiom!

---------

;; ($ERASE filearg) -> 0 if succeeds else 1
(defun $erase (&rest filearg)
  (setq filearg (make-full-namestring filearg))
  (if (probe-file filearg)
#+:CCL (delete-file filearg)
#+:AKCL
      (if (library-file filearg)
          (delete-directory filearg)
          (delete-file filearg))
      1))

(defun library-file (filename)
; (format t "library-file: ~a~%" filename)
 t)


#+:AKCL
(defun delete-directory (dirname)
   (system (concat "rm  -r " dirname)))

(defun $REPLACE (filespec1 filespec2)
    ($erase (setq filespec1 (make-full-namestring filespec1)))
    (rename-file (make-full-namestring filespec2) filespec1))

----------------

Elsewhere Axiom calls $REPLACE to replace xxx.NRLIB with the
contents of xxx.erlib. This used to work. What has changed?

The only thing I see here that I know has changed around about
gcl-2.6.7pre is 'probe-file'. The change was the 'probe-file'
returning nil for directories.

http://lists.nongnu.org/archive/html/axiom-developer/2005-05/msg00283.ht
ml

Yes, indeed! So now Axiom only deleted files but not directories!
It used to do both. I think what it wants to know is whether
the file or directory exists.

I should have remembered this:

http://lists.nongnu.org/archive/html/axiom-developer/2006-02/msg00219.ht
ml
http://lists.nongnu.org/archive/html/axiom-developer/2005-09/msg00045.ht
ml

Although the lisp spec is a horrible mish-mash, as near as I
can figure it

 (directory (truename filearg))

will test of a particular file or *directory* exists, although it
seems to do some kind of "wild card" since it also finds files
or directories that have something after a dot (.). So

 (directory (truename "xxx"))

returns a list of all files or directories of the form "xxx.*"
Contrary to the documentation at

http://www.cs.queensu.ca/software_docs/gnudev/gcl-ansi/gcl_1138.html#SEC
1138

Yuck!

Anyway it seems the following patch replacing (probe-file filearg)
with (directory (truename filearg)) should work (for Axiom's purposes
at least):

----------

;; ($ERASE filearg) -> 0 if succeeds else 1
(defun $erase (&rest filearg)
  (setq filearg (make-full-namestring filearg))
  (if (directory (truename filearg))
#+:CCL (delete-file filearg)
#+:AKCL
      (if (library-file filearg)
          (delete-directory filearg)
          (delete-file filearg))
      1))

----------

Any comments? Does anyone see how to do this a better way?

Regards,
Bill Page.