;;;; Objective-CL, an Objective-C bridge for Common Lisp.
;;;; Copyright (C) 2007 Matthias Andreas Benkard.
;;;;
;;;; This program is free software: you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public License
;;;; as published by the Free Software Foundation, either version 3 of
;;;; the License, or (at your option) any later version.
;;;;
;;;; This program is distributed in the hope that it will be useful, but
;;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;;; Lesser General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this program. If not, see
;;;; .
(in-package #:mulk.objective-cl)
;;;; (@* "Convenience types")
(deftype c-pointer ()
'(satisfies pointerp))
(deftype argument-number ()
`(integer 0 ,call-arguments-limit))
;;;; (@* "Foreign data types")
(defctype char-pointer :pointer)
;;;; (@* "Objective-C object wrapper classes")
(with-compilation-unit () ; needed for class finalization
(defclass c-pointer-wrapper ()
((pointer :type c-pointer
:reader pointer-to
:initarg :pointer
:initform (cffi:null-pointer)))))
(defmethod make-load-form ((instance c-pointer-wrapper) &optional environment)
(declare (ignore environment))
;; (TYPE-OF INSTANCE) works because MAKE-POINTER-WRAPPER accepts
;; subclasses of ID as well as ID itself.
`(make-pointer-wrapper ',(type-of instance)
:pointer (make-pointer
,(pointer-address (pointer-to instance)))))
;; The following may be needed by some implementations (namely Allegro
;; CL).
(eval-when (:compile-toplevel :load-toplevel :execute)
(loop for class-name in '(c2mop:funcallable-standard-object
c-pointer-wrapper)
for class = (find-class class-name nil)
when class
unless (c2mop:class-finalized-p class)
do (c2mop:finalize-inheritance class)))
;; FIXME: I'm not confident about this, but it is needed in order to
;; make (DEFCLASS SELECTOR ...) work.
;;
;; On the other hand, CLISP's implementation notes specify this method
;; to return true by default for "some `obvious' cases" [29.12] such as
;; this one. Therefore, we needn't override it. In fact, we can't, at
;; least without disabling #'s package lock.
#-clisp
(defmethod c2mop:validate-superclass ((class c2mop:funcallable-standard-class)
(superclass standard-class))
t)
(defclass selector (c2mop:funcallable-standard-object c-pointer-wrapper)
()
(:metaclass c2mop:funcallable-standard-class)
(:documentation "An Objective-C method selector.
## Description:
Method selectors are Objective-C's equivalent to what Common Lisp calls
**symbols**. Their use, however, is restricted to retrieving methods by
name.
In Common Lisp, you can **funcall** a __selector__ directly (see the
note below for details and why you may want to do this).
__selector__ objects cannot be created by means of __make-instance__.
Use __find-selector__ instead.
## Note:
Instead of using __invoke__, which is neither macro-friendly nor very
useful for method selection at run-time, you may **funcall** selectors
directly. Naturally, __apply__ works as well.
The following calls are all equivalent:
(invoke-by-name instance \"stringWithCString:encoding:\" \"Mulk.\" 4)
(invoke instance :string-with-c-string \"Mulk.\" :encoding 4)
(funcall (selector \"stringWithCString:encoding:\") instance \"Mulk.\" 4)
(apply (selector \"stringWithCString:encoding:\") (list instance \"Mulk.\" 4))
## See also:
__find-selector__"))
(defmethod shared-initialize :after ((selector selector)
slot-names
&rest initargs
&key
&allow-other-keys)
(declare (ignore slot-names initargs))
(c2mop:set-funcallable-instance-function
selector
#'(lambda (receiver &rest args)
(apply #'invoke-by-name receiver selector args))))
(defmethod make-load-form ((selector selector) &optional environment)
(declare (ignore environment))
`(make-pointer-wrapper 'selector
:pointer (make-pointer
,(pointer-address (pointer-to selector)))))
(defclass id (c-pointer-wrapper)
()
(:documentation "The type of all Objective-C objects.
## Description:
The class __id__ is the supertype of all Objective-C instance types. It
comprises all kinds of Objective-C objects that are instances of some
Objective-C class, that is, neither primitive C values nor __selector__,
__class__ or __exception__ objects.
__id__ objects cannot be created by means of __make-instance__. Use
a suitable class method instead as you would in Objective-C.
## Examples:
(invoke (find-objc-class 'ns-object)
'self)
;=> #
(invoke (find-objc-class 'ns-string)
:string-with-c-string \"Mulk.\")
;=> #
(invoke (find-objc-class 'ns-string)
'new)
;=> #
## See also:
__invoke__, __invoke-by-name__, __exception__"))
(defclass objective-c-class (standard-class c-pointer-wrapper)
((registered-p :type boolean
:accessor foreign-class-registered-p
:initform nil
:documentation
"Whether the class has been registered with the Objective-C runtime.")))
(defclass objective-c-meta-class (objective-c-class) ())
(define-condition exception (error)
((pointer :type c-pointer
:reader pointer-to
:initarg :pointer))
(:report (lambda (condition stream)
(format stream
"The Objective-C runtime has issued an exception of ~
type `~A'.~&~
Reason: ~A."
(invoke-by-name
(invoke-by-name condition "name")
"UTF8String")
(invoke-by-name
(invoke-by-name condition "reason")
"UTF8String"))))
(:documentation "The condition type for Objective-C exceptions.
## Description:
Whenever an Objective-C call made by means of __invoke__ or
__invoke-by-name__ raises an exception, the exception is propagated to
the Lisp side by being encapsulated in an __exception__ object and
signaled.
Note that it is currently impossible to directly extract the original
Objective-C exception from an __exception__ object, although it might
arguably be desirable to do so. As __exception__ objects behave just
like __id__ objects in almost all circumstances, this is not much of a
problem, though. If you really do need an __id__ instance rather than
an __exception__, you can simply send it the `self' message.
## Examples:
\(With __install-reader-syntax__ enabled.)
(handler-case
[NSArray selph] ; oops, typo
(exception (e)
e))
;=> #
(class-of *)
;=> #
(class-of [** self])
;=> #
## See also:
__id__"))
(defclass foreign-value (c-pointer-wrapper)
((lisp-managed-cell :type (array boolean ())
:accessor foreign-value-lisp-managed-cell-p
:initarg :lisp-managed-cell
:documentation "Whether we need to handle deallocation.")))
;; FIXME: Document.
(defclass foreign-struct (foreign-value)
((name :type (or null string)
:accessor foreign-struct-name
:initarg :name)))
;; The following are for private use only.
(defclass opaque-struct (foreign-struct) ())
(defclass tagged-struct (foreign-struct)
((typespec :reader foreign-value-typespec
:initarg :typespec)))
(defclass opaque-union (opaque-struct) ())
(defclass tagged-union (tagged-struct) ())
;; FIXME: Either document or throw away. (Does the C language actually
;; support returning arrays from functions? It certainly does not
;; support passing them as arguments.)
(defclass foreign-array (foreign-value)
((element-type :type symbol
:reader foreign-array-element-type
:initarg :element-type)
(length :type integer
:reader foreign-array-length
:initarg :type)
(typespec :reader foreign-value-typespec
:initarg :typespec)))
;; FIXME: Document.
(defgeneric foreign-value-lisp-managed-p (foreign-value))
(defmethod foreign-value-lisp-managed-p ((foreign-value foreign-value))
(with-slots (lisp-managed-cell) foreign-value
(aref lisp-managed-cell)))
;; FIXME: Document.
(defgeneric (setf foreign-value-lisp-managed-p) (managedp foreign-value))
(defmethod (setf foreign-value-lisp-managed-p)
(managedp (foreign-value foreign-value))
(with-slots (lisp-managed-cell) foreign-value
(setf (aref lisp-managed-cell) (if managedp t nil))))
;; FIXME: Document.
(defgeneric foreign-value-pointer (foreign-value))
(defmethod foreign-value-pointer ((foreign-value foreign-value))
(pointer-to foreign-value))
(defun make-struct-wrapper (pointer typespec managedp)
;; We use a zero-dimensional array that the finaliser can close over
;; so that it (the finaliser) can decide whether to garbage-collect
;; the foreign data.
;;
;; Using the instance slot directly would be both easier and more
;; transparent, of course, but it also wouldn't work, because during
;; finalisation, the instance is not in a usable state anymore.
(let ((managedp-cell (make-array '() :element-type 'boolean
:initial-element managedp)))
(flet ((finaliser ()
(when (aref managedp-cell)
(foreign-free pointer))))
(let ((new-wrapper (make-instance (ecase (typespec-primary-type typespec)
(struct 'tagged-struct)
(union 'tagged-union))
:name (third typespec)
:typespec typespec
:pointer pointer
:lisp-managed-cell managedp-cell)))
(when managedp
(trivial-garbage:finalize new-wrapper #'finaliser))))))
(defgeneric objcl-eql (obj1 obj2))
(defmethod objcl-eql ((obj1 c-pointer-wrapper) (obj2 c-pointer-wrapper))
(pointer-eq (pointer-to obj1) (pointer-to obj2)))
(defmethod objcl-eql (obj1 obj2)
(eql obj1 obj2))