+(defun import-list-symbols (import-list)
+ (let ((symbols nil))
+ (dolist (import import-list symbols)
+ (destructuring-bind (package-name &rest symbol-names)
+ import
+ (let ((package (find-undeleted-package-or-lose package-name)))
+ (mapcar (lambda (name)
+ (push (find-or-make-symbol name package) symbols))
+ symbol-names))))))
+
+(defun use-list-packages (package package-designators)
+ (cond ((listp package-designators)
+ (mapcar #'find-undeleted-package-or-lose package-designators))
+ (package
+ ;; :default for an existing package means preserve the
+ ;; existing use list
+ (package-use-list package))
+ (t
+ ;; :default for a new package is the *default-package-use-list*
+ '#.*default-package-use-list*)))
+
+(defun update-package (package nicknames source-location
+ shadows shadowing-imports
+ use
+ imports interns
+ exports implement local-nicknames
+ lock doc-string)
+ (declare #!-sb-package-locks
+ (ignore implement lock))
+ (%enter-new-nicknames package nicknames)
+ ;; 1. :shadow and :shadowing-import-from
+ ;;
+ ;; shadows is a list of strings, shadowing-imports is a list of symbols.
+ (shadow shadows package)
+ (shadowing-import shadowing-imports package)
+ ;; 2. :use
+ ;;
+ ;; use is a list of package objects.
+ (use-package use package)
+ ;; 3. :import-from and :intern
+ ;;
+ ;; imports is a list of symbols. interns is a list of strings.
+ (import imports package)
+ (dolist (intern interns)
+ (intern intern package))
+ ;; 4. :export
+ ;;
+ ;; exports is a list of strings
+ (export (mapcar (lambda (symbol-name) (intern symbol-name package))
+ exports)
+ package)
+ ;; Everything was created: update metadata
+ (sb!c:with-source-location (source-location)
+ (setf (package-source-location package) source-location))
+ (setf (package-doc-string package) doc-string)
+ #!+sb-package-locks
+ (progn
+ ;; Handle packages this is an implementation package of
+ (dolist (p implement)
+ (add-implementation-package package p))
+ ;; Handle lock
+ (setf (package-lock package) lock))
+ ;; Local nicknames. Throw out the old ones.
+ (setf (package-%local-nicknames package) nil)
+ (dolist (spec local-nicknames)
+ (add-package-local-nickname (car spec) (cdr spec) package))
+ package)
+
+(declaim (type list *on-package-variance*))
+(defvar *on-package-variance* '(:warn t)
+ "Specifies behavior when redefining a package using DEFPACKAGE and the
+definition is in variance with the current state of the package.
+
+The value should be of the form:
+
+ (:WARN [T | packages-names] :ERROR [T | package-names])
+
+specifying which packages get which behaviour -- with T signifying the default unless
+otherwise specified. If default is not specified, :WARN is used.
+
+:WARN keeps as much state as possible and causes SBCL to signal a full warning.
+
+:ERROR causes SBCL to signal an error when the variant DEFPACKAGE form is executed,
+with restarts provided for user to specify what action should be taken.
+
+Example:
+
+ (setf *on-package-variance* '(:warn (:swank :swank-backend) :error t))
+
+specifies to signal a warning if SWANK package is in variance, and an error otherwise.")
+
+(defun note-package-variance (&rest args &key package &allow-other-keys)
+ (let ((pname (package-name package)))
+ (destructuring-bind (&key warn error) *on-package-variance*
+ (let ((what (cond ((and (listp error) (member pname error :test #'string=))
+ :error)
+ ((and (listp warn) (member pname warn :test #'string=))
+ :warn)
+ ((eq t error)
+ :error)
+ (t
+ :warn))))
+ (ecase what
+ (:error
+ (apply #'error 'sb!kernel::package-at-variance-error args))
+ (:warn
+ (apply #'warn 'sb!kernel::package-at-variance args)))))))
+
+(defun update-package-with-variance (package name nicknames source-location
+ shadows shadowing-imports
+ use
+ imports interns
+ exports
+ implement local-nicknames
+ lock doc-string)
+ (unless (string= (the string (package-name package)) name)
+ (error 'simple-package-error
+ :package name
+ :format-control "~A is a nickname for the package ~A"
+ :format-arguments (list name (package-name name))))
+ (let ((no-longer-shadowed
+ (set-difference (package-%shadowing-symbols package)
+ (append shadows shadowing-imports)
+ :test #'string=)))
+ (when no-longer-shadowed
+ (restart-case
+ (let ((*package* (find-package :keyword)))
+ (note-package-variance
+ :format-control "~A also shadows the following symbols:~% ~S"
+ :format-arguments (list name no-longer-shadowed)
+ :package package))
+ (drop-them ()
+ :report "Stop shadowing them by uninterning them."
+ (dolist (sym no-longer-shadowed)
+ (unintern sym package)))
+ (keep-them ()
+ :report "Keep shadowing them."))))
+ (let ((no-longer-used (set-difference (package-use-list package) use)))
+ (when no-longer-used
+ (restart-case
+ (note-package-variance
+ :format-control "~A also uses the following packages:~% ~A"
+ :format-arguments (list name (mapcar #'package-name no-longer-used))
+ :package package)
+ (drop-them ()
+ :report "Stop using them."
+ (unuse-package no-longer-used package))
+ (keep-them ()
+ :report "Keep using them."))))
+ (let (old-exports)
+ (do-external-symbols (s package)
+ (push s old-exports))
+ (let ((no-longer-exported (set-difference old-exports exports :test #'string=)))
+ (when no-longer-exported
+ (restart-case
+ (note-package-variance
+ :format-control "~A also exports the following symbols:~% ~S"
+ :format-arguments (list name no-longer-exported)
+ :package package)
+ (drop-them ()
+ :report "Unexport them."
+ (unexport no-longer-exported package))
+ (keep-them ()
+ :report "Keep exporting them.")))))
+ (let ((old-implements
+ (set-difference (package-implements-list package)
+ (mapcar #'find-undeleted-package-or-lose implement))))
+ (when old-implements
+ (restart-case
+ (note-package-variance
+ :format-control "~A is also an implementation package for:~% ~{~S~^~% ~}"
+ :format-arguments (list name old-implements)
+ :package package)
+ (drop-them ()
+ :report "Stop being an implementation package for them."
+ (dolist (p old-implements)
+ (remove-implementation-package package p)))
+ (keep-them ()
+ :report "Keep exporting them."))))
+ (update-package package nicknames source-location
+ shadows shadowing-imports
+ use imports interns exports
+ implement local-nicknames
+ lock doc-string))