src/code/defpackage.lisp

   1 ;;;; the DEFPACKAGE macro
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!IMPL")
  13
  14 ;;; the list of packages to use by default when no :USE argument is
  15 ;;; supplied to MAKE-PACKAGE or other package creation forms
  16 ;;;
  17 ;;; ANSI specifies (1) that MAKE-PACKAGE and DEFPACKAGE use the same
  18 ;;; value, and (2) that it (as an implementation-defined value) should
  19 ;;; be documented, which we do in the doc string. So for OAOO reasons
  20 ;;; we represent this value as a variable only at compile time, and
  21 ;;; then use #. readmacro hacks to splice it into the target code as a
  22 ;;; constant.
  23 (eval-when (:compile-toplevel)
  24   (defparameter *default-package-use-list*
  25     ;; ANSI says this is implementation-defined. So we make it NIL,
  26     ;; the way God intended. Anyone who actually wants a random value
  27     ;; is free to :USE (PACKAGE-USE-LIST :CL-USER) anyway.:-|
  28     nil))
  29
  30 (defmacro defpackage (package &rest options)
  31   #!+sb-doc
  32   #.(format nil
  33   "Defines a new package called PACKAGE. Each of OPTIONS should be one of the
  34    following: ~{~&~4T~A~}
  35    All options except ~{~A, ~}and :DOCUMENTATION can be used multiple
  36    times."
  37   '((:nicknames "{package-name}*")
  38     (:size "<integer>")
  39     (:shadow "{symbol-name}*")
  40     (:shadowing-import-from "<package-name> {symbol-name}*")
  41     (:use "{package-name}*")
  42     (:import-from "<package-name> {symbol-name}*")
  43     (:intern "{symbol-name}*")
  44     (:export "{symbol-name}*")
  45     #!+sb-package-locks (:implement "{package-name}*")
  46     #!+sb-package-locks (:lock "boolean")
  47     (:documentation "doc-string"))
  48   '(:size #!+sb-package-locks :lock))
  49   (let ((nicknames nil)
  50         (size nil)
  51         (shadows nil)
  52         (shadowing-imports nil)
  53         (use nil)
  54         (use-p nil)
  55         (imports nil)
  56         (interns nil)
  57         (exports nil)
  58         (implement (stringify-package-designators (list package)))
  59         (implement-p nil)
  60         (lock nil)
  61         (doc nil))
  62     #!-sb-package-locks
  63     (declare (ignore implement-p))
  64     (dolist (option options)
  65       (unless (consp option)
  66         (error 'simple-program-error
  67                :format-control "bogus DEFPACKAGE option: ~S"
  68                :format-arguments (list option)))
  69       (case (car option)
  70         (:nicknames
  71          (setf nicknames (stringify-package-designators (cdr option))))
  72         (:size
  73          (cond (size
  74                 (error 'simple-program-error
  75                        :format-control "can't specify :SIZE twice."))
  76                ((and (consp (cdr option))
  77                      (typep (second option) 'unsigned-byte))
  78                 (setf size (second option)))
  79                (t
  80                 (error
  81                  'simple-program-error
  82                  :format-control ":SIZE is not a positive integer: ~S"
  83                  :format-arguments (list (second option))))))
  84         (:shadow
  85          (let ((new (stringify-string-designators (cdr option))))
  86            (setf shadows (append shadows new))))
  87         (:shadowing-import-from
  88          (let ((package-name (stringify-package-designator (second option)))
  89                (names (stringify-string-designators (cddr option))))
  90            (let ((assoc (assoc package-name shadowing-imports
  91                                :test #'string=)))
  92              (if assoc
  93                  (setf (cdr assoc) (append (cdr assoc) names))
  94                  (setf shadowing-imports
  95                        (acons package-name names shadowing-imports))))))
  96         (:use
  97          (setf use (append use (stringify-package-designators (cdr option)) )
  98                use-p t))
  99         (:import-from
 100          (let ((package-name (stringify-package-designator (second option)))
 101                (names (stringify-string-designators (cddr option))))
 102            (let ((assoc (assoc package-name imports
 103                                :test #'string=)))
 104              (if assoc
 105                  (setf (cdr assoc) (append (cdr assoc) names))
 106                  (setf imports (acons package-name names imports))))))
 107         (:intern
 108          (let ((new (stringify-string-designators (cdr option))))
 109            (setf interns (append interns new))))
 110         (:export
 111          (let ((new (stringify-string-designators (cdr option))))
 112            (setf exports (append exports new))))
 113         #!+sb-package-locks
 114         (:implement
 115          (unless implement-p
 116            (setf implement nil))
 117          (let ((new (stringify-package-designators (cdr option))))
 118            (setf implement (append implement new)
 119                  implement-p t)))
 120         #!+sb-package-locks
 121         (:lock
 122          (when lock
 123            (error 'simple-program-error
 124                   :format-control "multiple :LOCK options"))
 125          (setf lock (coerce (second option) 'boolean)))
 126         (:documentation
 127          (when doc
 128            (error 'simple-program-error
 129                   :format-control "multiple :DOCUMENTATION options"))
 130          (setf doc (coerce (second option) 'simple-string)))
 131         (t
 132          (error 'simple-program-error
 133                 :format-control "bogus DEFPACKAGE option: ~S"
 134                 :format-arguments (list option)))))
 135     (check-disjoint `(:intern ,@interns) `(:export  ,@exports))
 136     (check-disjoint `(:intern ,@interns)
 137                     `(:import-from
 138                       ,@(apply #'append (mapcar #'rest imports)))
 139                     `(:shadow ,@shadows)
 140                     `(:shadowing-import-from
 141                       ,@(apply #'append (mapcar #'rest shadowing-imports))))
 142     `(eval-when (:compile-toplevel :load-toplevel :execute)
 143        (%defpackage ,(stringify-string-designator package) ',nicknames ',size
 144                     ',shadows ',shadowing-imports ',(if use-p use :default)
 145                     ',imports ',interns ',exports ',implement ',lock ',doc
 146                     (sb!c:source-location)))))
 147
 148 (defun check-disjoint (&rest args)
 149   ;; An arg is (:key . set)
 150   (do ((list args (cdr list)))
 151       ((endp list))
 152     (loop
 153       with x = (car list)
 154       for y in (rest list)
 155       for z = (remove-duplicates (intersection (cdr x)(cdr y) :test #'string=))
 156       when z do (error 'simple-program-error
 157                        :format-control "Parameters ~S and ~S must be disjoint ~
 158                                         but have common elements ~%   ~S"
 159                        :format-arguments (list (car x)(car y) z)))))
 160
 161 (defun stringify-string-designator (string-designator)
 162   (typecase string-designator
 163     (simple-string string-designator)
 164     (string (coerce string-designator 'simple-string))
 165     (symbol (symbol-name string-designator))
 166     (character (string string-designator))
 167     (t
 168      (error "~S does not designate a string" string-designator))))
 169
 170 (defun stringify-string-designators (string-designators)
 171   (mapcar #'stringify-string-designator string-designators))
 172
 173 (defun stringify-package-designator (package-designator)
 174   (typecase package-designator
 175     (simple-string package-designator)
 176     (string (coerce package-designator 'simple-string))
 177     (symbol (symbol-name package-designator))
 178     (character (string package-designator))
 179     (package (package-name package-designator))
 180     (t
 181      (error "~S does not designate a package" package-designator))))
 182
 183 (defun stringify-package-designators (package-designators)
 184   (mapcar #'stringify-package-designator package-designators))
 185
 186 (defun import-list-symbols (import-list)
 187   (let ((symbols nil))
 188     (dolist (import import-list symbols)
 189       (destructuring-bind (package-name &rest symbol-names)
 190           import
 191         (let ((package (find-undeleted-package-or-lose package-name)))
 192           (mapcar (lambda (name)
 193                     (push (find-or-make-symbol name package) symbols))
 194                   symbol-names))))))
 195
 196 (defun use-list-packages (package package-designators)
 197   (cond ((listp package-designators)
 198          (mapcar #'find-undeleted-package-or-lose package-designators))
 199         (package
 200          ;; :default for an existing package means preserve the
 201          ;; existing use list
 202          (package-use-list package))
 203         (t
 204          ;; :default for a new package is the *default-package-use-list*
 205          '#.*default-package-use-list*)))
 206
 207 (defun update-package (package nicknames source-location
 208                        shadows shadowing-imports
 209                        use
 210                        imports interns
 211                        exports
 212                        implement lock doc-string)
 213   (declare #!-sb-package-locks
 214            (ignore implement lock))
 215   (enter-new-nicknames package nicknames)
 216   ;; 1. :shadow and :shadowing-import-from
 217   ;;
 218   ;; shadows is a list of strings, shadowing-imports is a list of symbols.
 219   (shadow shadows package)
 220   (shadowing-import shadowing-imports package)
 221   ;; 2. :use
 222   ;;
 223   ;; use is a list of package objects.
 224   (use-package use package)
 225   ;; 3. :import-from and :intern
 226   ;;
 227   ;; imports is a list of symbols. interns is a list of strings.
 228   (import imports package)
 229   (dolist (intern interns)
 230     (intern intern package))
 231   ;; 4. :export
 232   ;;
 233   ;; exports is a list of strings
 234   (export (mapcar (lambda (symbol-name) (intern symbol-name package))
 235                   exports)
 236           package)
 237   ;; Everything was created: update metadata
 238   (sb!c:with-source-location (source-location)
 239     (setf (package-source-location package) source-location))
 240   (setf (package-doc-string package) doc-string)
 241   #!+sb-package-locks
 242   (progn
 243     ;; Handle packages this is an implementation package of
 244     (dolist (p implement)
 245       (add-implementation-package package p))
 246     ;; Handle lock
 247     (setf (package-lock package) lock))
 248   package)
 249
 250 (defun update-package-with-variance (package name nicknames source-location
 251                                      shadows shadowing-imports
 252                                      use
 253                                      imports interns
 254                                      exports
 255                                      implement lock doc-string)
 256   (let ((old-exports nil)
 257         (old-shadows (package-%shadowing-symbols package))
 258         (old-use (package-use-list package))
 259         (no-longer-used nil))
 260     (unless (string= (the string (package-name package)) name)
 261       (error 'simple-package-error
 262              :package name
 263              :format-control "~A is a nickname for the package ~A"
 264              :format-arguments (list name (package-name name))))
 265     (do-external-symbols (symbol package)
 266       (push symbol old-exports))
 267     (setf old-shadows (set-difference old-shadows (append shadows
 268                                                           shadowing-imports)
 269                                       :test #'string=))
 270     (setf no-longer-used (set-difference old-use use))
 271     (setf use (set-difference use old-use))
 272     (setf old-exports (set-difference old-exports exports :test #'string=))
 273     (when old-shadows
 274       (warn 'package-at-variance
 275             :format-control "~A also shadows the following symbols:~%  ~S"
 276             :format-arguments (list name old-shadows)))
 277     (when no-longer-used
 278       (dolist (unused-package no-longer-used)
 279         (unuse-package unused-package package))
 280       (warn 'package-at-variance
 281             :format-control "~A used to use the following packages:~%  ~S"
 282             :format-arguments (list name no-longer-used)))
 283     (when old-exports
 284       (warn 'package-at-variance
 285             :format-control "~A also exports the following symbols:~%  ~S"
 286             :format-arguments (list name old-exports)))
 287     (update-package package nicknames source-location
 288                     shadows shadowing-imports
 289                     use imports interns exports
 290                     implement lock doc-string)))
 291
 292 (defun %defpackage (name nicknames size shadows shadowing-imports
 293                     use imports interns exports implement lock doc-string
 294                     source-location)
 295   (declare (type simple-string name)
 296            (type list nicknames shadows shadowing-imports
 297                  imports interns exports)
 298            (type (or list (member :default)) use)
 299            (type (or simple-string null) doc-string)
 300            #!-sb-package-locks
 301            (ignore implement lock))
 302   (let* ((existing-package (find-package name))
 303          (use (use-list-packages existing-package use))
 304          (shadowing-imports (import-list-symbols shadowing-imports))
 305          (imports (import-list-symbols imports)))
 306     (if existing-package
 307         (update-package-with-variance existing-package name
 308                                       nicknames source-location
 309                                       shadows shadowing-imports
 310                                       use imports interns exports
 311                                       implement lock doc-string)
 312         (let ((package (make-package name
 313                                      :use nil
 314                                      :internal-symbols (or size 10)
 315                                      :external-symbols (length exports))))
 316           (update-package package
 317                           nicknames source-location
 318                           shadows shadowing-imports
 319                           use imports interns exports
 320                           implement lock doc-string)))))
 321
 322 (defun find-or-make-symbol (name package)
 323   (multiple-value-bind (symbol how) (find-symbol name package)
 324     (cond (how
 325            symbol)
 326           (t
 327            (with-simple-restart (continue "INTERN it.")
 328              (error 'simple-package-error
 329                     :package package
 330                     :format-control "no symbol named ~S in ~S"
 331                     :format-arguments (list name (package-name package))))
 332            (intern name package)))))