1 ;;;; REQUIRE, PROVIDE, and friends
3 ;;;; Officially these are deprecated, but in practice they're probably
4 ;;;; even less likely to actually go away than there is to ever be
5 ;;;; another revision of the standard.
7 ;;;; This software is part of the SBCL system. See the README file for
10 ;;;; This software is derived from the CMU CL system, which was
11 ;;;; written at Carnegie Mellon University and released into the
12 ;;;; public domain. The software is in the public domain and is
13 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
14 ;;;; files for more information.
16 (in-package "SB!IMPL")
18 ;;;; exported specials
22 "This is a list of module names that have been loaded into Lisp so far.
23 It is used by PROVIDE and REQUIRE.")
25 (defvar *module-provider-functions* '(module-provide-contrib)
26 "See function documentation for REQUIRE")
28 ;;;; PROVIDE and REQUIRE
30 (defun provide (module-name)
32 "Adds a new module name to *MODULES* indicating that it has been loaded.
33 Module-name is a string designator"
34 (pushnew (string module-name) *modules* :test #'string=)
37 (defun require (module-name &optional pathnames)
39 "Loads a module, unless it already has been loaded. PATHNAMES, if supplied,
40 is a designator for a list of pathnames to be loaded if the module
41 needs to be. If PATHNAMES is not supplied, functions from the list
42 *MODULE-PROVIDER-FUNCTIONS* are called in order with MODULE-NAME
43 as an argument, until one of them returns non-NIL. User code is
44 responsible for calling PROVIDE to indicate a successful load of the
46 (let ((saved-modules (copy-list *modules*)))
47 (unless (member (string module-name) *modules* :test #'string=)
49 (unless (listp pathnames) (setf pathnames (list pathnames)))
50 ;; ambiguity in standard: should we try all pathnames in the
51 ;; list, or should we stop as soon as one of them calls PROVIDE?
52 (dolist (ele pathnames t)
55 (unless (some (lambda (p) (funcall p module-name))
56 *module-provider-functions*)
57 (error 'extension-failure
58 :format-control "Don't know how to ~S ~A"
59 :format-arguments (list 'require module-name)
62 '(:sbcl :variable *module-provider-functions*)))))))
63 (set-difference *modules* saved-modules)))
67 (defun module-provide-contrib (name)
68 "Stringify and downcase NAME, then attempt to load the file
70 (let* ((filesys-name (string-downcase (string name)))
73 (make-pathname :directory (list :relative filesys-name)
75 (truename (posix-getenv "SBCL_HOME"))))
76 (fasl-path (merge-pathnames
77 (make-pathname :type *fasl-file-type*)
79 (lisp-path (merge-pathnames (make-pathname :type "lisp")
81 ;; KLUDGE: there's a race condition here; the file we probe could
82 ;; be removed by the time we get round to trying to load it.
83 ;; Maybe factor out the logic in the LOAD guesser as to which file
84 ;; was meant, so that we can use it here on open streams instead?
85 (when (or (probe-file unadorned-path)
86 (probe-file fasl-path)
87 (probe-file lisp-path))