rename-file-overwriting-target in clisp problems

[sds]

This function has a special case for clisp:

  (defun rename-file-overwriting-target (source target)
    #+clisp ;; But for a bug in CLISP 2.48, we should use :if-exists :overwrite and be atomic
    (posix:copy-file source target :method :rename)
    #-clisp
    (rename-file source target
                 #+clozure :if-exists #+clozure :rename-and-delete))

This code causes build problems in clisp because when asdf is distributed with clisp, it is built before the posix module is available.
Also, nobody uses 2.48 anymore, so I think you can safely assume 2.49.

It would seem that a more portable (but not atomic) solution would be

(defun rename-file-overwriting-target (source target)
  #-clozure (when (probe-file target) (delete-file target))
  (rename-file source target
                 #+clozure :if-exists #+clozure :rename-and-delete))

Alternatively, the CLISP solution would be

#+clisp
(progn (require "syscalls")
             (funcall (find-symbol "COPY-FILE" "POSIX") source target :method :rename :if-exists :rename-and-delete))

[Faré (fahree)]

OK. Is there a simple way to detect whether the :if-exists :overwrite option is available?
If I try to use it on my Ubuntu 12.04.3 LTS's "GNU CLISP 2.49 (2010-07-07)", I get:

(posix:copy-file "/tmp/b" "/tmp/c" :method :rename :if-exists :overwrite)

*** - EVAL/APPLY: Too many arguments (4 instead of at most 2) given to RENAME-FILE

[Faré (fahree)]

Also, when I started using this:
    #+clisp ;; in recent enough versions of CLISP, :if-exists :overwrite would make it atomic
    (progn (require "syscalls")
           (symbol-call :posix :copy-file source target :method :rename))
the asdf-pathname-test died with:
;; Loaded file /home/tunes/cl/asdf/test/test-asdf.asd
;;; 20131016T175450Z : CLISP 2.49+ (2010-07-17) (built on lux [127.0.0.1]) 3.0.2.26

*** - handle_fault error2 ! address = 0xccd05dee0 not in [0x3349c8000,0x334c8a1f0) !
SIGSEGV cannot be cured. Fault address = 0xccd05dee0.
GC count: 69
Space collected by GC: 68455336
Run time: 1 276079
Real time: 8 907945
GC time: 0 280019
Permanently allocated: 165312 bytes.
Currently in use: 5260080 bytes.
Free space: 1096036 bytes.

Sorry, no backtrace.

[Faré (fahree)]

(All other tests pass fine with this modification.)

[sds (sds-gnu)]

you can use arglist:

> (sys::arglist #'posix:copy-file)
(#:ARG0 #:ARG1 &KEY :METHOD :PRESERVE :IF-EXISTS :IF-DOES-NOT-EXIST)

but I suggest that you separate the two issues: whether IF-EXISTS works and my build problem.

thanks.

[Faré (fahree)]

To defeat clisp optimization, I actually had to use
  (funcall 'require "syscalls")
instead of
  (require "syscalls")
that allows me to build CLISP from hg, but somehow running its clisp binary still ends up invoking the system's CLISP.

Annoyingly, the new CLISP has the exact same version string as the previous one with a version date of "2010-07-17", though at least it doesn't segfault with version on the asdf-pathname-test:
   cd ~/cl/asdf
   make t l=clisp t=asdf-pathname-test.script
Now works!

Committed as 3.0.2.27

[Faré (fahree)]

I tried this:
    (progn
      (funcall 'require "syscalls")
      (let ((copy-file (find-symbol* :copy-file :posix)))
        (apply copy-file source target :method :rename
               (when (member :if-exists (sys::arglist copy-file)) '(:if-exists :overwrite)))))

But I get massive errors of this kind:
EVAL/APPLY: Too many arguments (4 instead of at most 2) given to RENAME-FILE

[Faré (fahree)]

Released in 3.0.3.