ttypes.lisp - clic - Clic is an command line interactive client for gopher written in Common LISP
(HTM) git clone git://bitreich.org/clic/ git://hg6vgqziawt5s4dj.onion/clic/
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ttypes.lisp (44615B)
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1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
2 ;;;
3 ;;; types.lisp --- User-defined CFFI types.
4 ;;;
5 ;;; Copyright (C) 2005-2006, James Bielman <jamesjb@jamesjb.com>
6 ;;; Copyright (C) 2005-2007, Luis Oliveira <loliveira@common-lisp.net>
7 ;;;
8 ;;; Permission is hereby granted, free of charge, to any person
9 ;;; obtaining a copy of this software and associated documentation
10 ;;; files (the "Software"), to deal in the Software without
11 ;;; restriction, including without limitation the rights to use, copy,
12 ;;; modify, merge, publish, distribute, sublicense, and/or sell copies
13 ;;; of the Software, and to permit persons to whom the Software is
14 ;;; furnished to do so, subject to the following conditions:
15 ;;;
16 ;;; The above copyright notice and this permission notice shall be
17 ;;; included in all copies or substantial portions of the Software.
18 ;;;
19 ;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 ;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 ;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 ;;; NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
23 ;;; HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
24 ;;; WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 ;;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26 ;;; DEALINGS IN THE SOFTWARE.
27 ;;;
28
29 (in-package #:cffi)
30
31 ;;;# Built-In Types
32
33 ;; NOTE: In the C standard there's a "signed-char":
34 ;; https://stackoverflow.com/questions/436513/char-signed-char-char-unsigned-char
35 ;; and "char" may be either signed or unsigned, i.e. treating it as a small int
36 ;; is not wise. At the level of CFFI we can safely ignore this and assume that
37 ;; :char is mapped to "signed-char" by the CL implementation under us.
38 (define-built-in-foreign-type :char)
39 (define-built-in-foreign-type :unsigned-char)
40 (define-built-in-foreign-type :short)
41 (define-built-in-foreign-type :unsigned-short)
42 (define-built-in-foreign-type :int)
43 (define-built-in-foreign-type :unsigned-int)
44 (define-built-in-foreign-type :long)
45 (define-built-in-foreign-type :unsigned-long)
46 (define-built-in-foreign-type :float)
47 (define-built-in-foreign-type :double)
48 (define-built-in-foreign-type :void)
49
50 #-cffi-sys::no-long-long
51 (progn
52 (define-built-in-foreign-type :long-long)
53 (define-built-in-foreign-type :unsigned-long-long))
54
55 ;;; Define emulated LONG-LONG types. Needs checking whether we're
56 ;;; using the right sizes on various platforms.
57 ;;;
58 ;;; A possibly better, certainly faster though more intrusive,
59 ;;; alternative is available here:
60 ;;; <http://article.gmane.org/gmane.lisp.cffi.devel/1091>
61 #+cffi-sys::no-long-long
62 (eval-when (:compile-toplevel :load-toplevel :execute)
63 (defclass emulated-llong-type (foreign-type) ())
64 (defmethod foreign-type-size ((tp emulated-llong-type)) 8)
65 (defmethod foreign-type-alignment ((tp emulated-llong-type))
66 ;; better than assuming that the alignment is 8
67 (foreign-type-alignment :long))
68 (defmethod aggregatep ((tp emulated-llong-type)) nil)
69
70 (define-foreign-type emulated-llong (emulated-llong-type)
71 ()
72 (:simple-parser :long-long))
73
74 (define-foreign-type emulated-ullong (emulated-llong-type)
75 ()
76 (:simple-parser :unsigned-long-long))
77
78 (defmethod canonicalize ((tp emulated-llong)) :long-long)
79 (defmethod unparse-type ((tp emulated-llong)) :long-long)
80 (defmethod canonicalize ((tp emulated-ullong)) :unsigned-long-long)
81 (defmethod unparse-type ((tp emulated-ullong)) :unsigned-long-long)
82
83 (defun %emulated-mem-ref-64 (ptr type offset)
84 (let ((value #+big-endian
85 (+ (ash (mem-ref ptr :unsigned-long offset) 32)
86 (mem-ref ptr :unsigned-long (+ offset 4)))
87 #+little-endian
88 (+ (mem-ref ptr :unsigned-long offset)
89 (ash (mem-ref ptr :unsigned-long (+ offset 4)) 32))))
90 (if (and (eq type :long-long) (logbitp 63 value))
91 (lognot (logxor value #xFFFFFFFFFFFFFFFF))
92 value)))
93
94 (defun %emulated-mem-set-64 (value ptr type offset)
95 (when (and (eq type :long-long) (minusp value))
96 (setq value (lognot (logxor value #xFFFFFFFFFFFFFFFF))))
97 (%mem-set (ldb (byte 32 0) value) ptr :unsigned-long
98 #+big-endian (+ offset 4) #+little-endian offset)
99 (%mem-set (ldb (byte 32 32) value) ptr :unsigned-long
100 #+big-endian offset #+little-endian (+ offset 4))
101 value))
102
103 ;;; When some lisp other than SCL supports :long-double we should
104 ;;; use #-cffi-sys::no-long-double here instead.
105 #+(and scl long-float) (define-built-in-foreign-type :long-double)
106
107 (defparameter *possible-float-types* '(:float :double :long-double))
108
109 (defparameter *other-builtin-types* '(:pointer :void)
110 "List of types other than integer or float built in to CFFI.")
111
112 (defparameter *built-in-integer-types*
113 (set-difference
114 cffi:*built-in-foreign-types*
115 (append *possible-float-types* *other-builtin-types*))
116 "List of integer types supported by CFFI.")
117
118 (defparameter *built-in-float-types*
119 (set-difference
120 cffi:*built-in-foreign-types*
121 (append *built-in-integer-types* *other-builtin-types*))
122 "List of real float types supported by CFFI.")
123
124 ;;;# Foreign Pointers
125
126 (define-modify-macro incf-pointer (&optional (offset 1)) inc-pointer)
127
128 (defun mem-ref (ptr type &optional (offset 0))
129 "Return the value of TYPE at OFFSET bytes from PTR. If TYPE is aggregate,
130 we don't return its 'value' but a pointer to it, which is PTR itself."
131 (let* ((parsed-type (parse-type type))
132 (ctype (canonicalize parsed-type)))
133 #+cffi-sys::no-long-long
134 (when (member ctype '(:long-long :unsigned-long-long))
135 (return-from mem-ref
136 (translate-from-foreign (%emulated-mem-ref-64 ptr ctype offset)
137 parsed-type)))
138 ;; normal branch
139 (if (aggregatep parsed-type)
140 (if (bare-struct-type-p parsed-type)
141 (inc-pointer ptr offset)
142 (translate-from-foreign (inc-pointer ptr offset) parsed-type))
143 (translate-from-foreign (%mem-ref ptr ctype offset) parsed-type))))
144
145 (define-compiler-macro mem-ref (&whole form ptr type &optional (offset 0))
146 "Compiler macro to open-code MEM-REF when TYPE is constant."
147 (if (constantp type)
148 (let* ((parsed-type (parse-type (eval type)))
149 (ctype (canonicalize parsed-type)))
150 ;; Bail out when using emulated long long types.
151 #+cffi-sys::no-long-long
152 (when (member ctype '(:long-long :unsigned-long-long))
153 (return-from mem-ref form))
154 (if (aggregatep parsed-type)
155 (if (bare-struct-type-p parsed-type)
156 `(inc-pointer ,ptr ,offset)
157 (expand-from-foreign `(inc-pointer ,ptr ,offset) parsed-type))
158 (expand-from-foreign `(%mem-ref ,ptr ,ctype ,offset) parsed-type)))
159 form))
160
161 (defun mem-set (value ptr type &optional (offset 0))
162 "Set the value of TYPE at OFFSET bytes from PTR to VALUE."
163 (let* ((ptype (parse-type type))
164 (ctype (canonicalize ptype)))
165 #+cffi-sys::no-long-long
166 (when (or (eq ctype :long-long) (eq ctype :unsigned-long-long))
167 (return-from mem-set
168 (%emulated-mem-set-64 (translate-to-foreign value ptype)
169 ptr ctype offset)))
170 (if (aggregatep ptype) ; XXX: backwards incompatible?
171 (translate-into-foreign-memory value ptype (inc-pointer ptr offset))
172 (%mem-set (translate-to-foreign value ptype) ptr ctype offset))))
173
174 (define-setf-expander mem-ref (ptr type &optional (offset 0) &environment env)
175 "SETF expander for MEM-REF that doesn't rebind TYPE.
176 This is necessary for the compiler macro on MEM-SET to be able
177 to open-code (SETF MEM-REF) forms."
178 (multiple-value-bind (dummies vals newval setter getter)
179 (get-setf-expansion ptr env)
180 (declare (ignore setter newval))
181 ;; if either TYPE or OFFSET are constant, we avoid rebinding them
182 ;; so that the compiler macros on MEM-SET and %MEM-SET work.
183 (with-unique-names (store type-tmp offset-tmp)
184 (values
185 (append (unless (constantp type) (list type-tmp))
186 (unless (constantp offset) (list offset-tmp))
187 dummies)
188 (append (unless (constantp type) (list type))
189 (unless (constantp offset) (list offset))
190 vals)
191 (list store)
192 `(progn
193 (mem-set ,store ,getter
194 ,@(if (constantp type) (list type) (list type-tmp))
195 ,@(if (constantp offset) (list offset) (list offset-tmp)))
196 ,store)
197 `(mem-ref ,getter
198 ,@(if (constantp type) (list type) (list type-tmp))
199 ,@(if (constantp offset) (list offset) (list offset-tmp)))))))
200
201 (define-compiler-macro mem-set
202 (&whole form value ptr type &optional (offset 0))
203 "Compiler macro to open-code (SETF MEM-REF) when type is constant."
204 (if (constantp type)
205 (let* ((parsed-type (parse-type (eval type)))
206 (ctype (canonicalize parsed-type)))
207 ;; Bail out when using emulated long long types.
208 #+cffi-sys::no-long-long
209 (when (member ctype '(:long-long :unsigned-long-long))
210 (return-from mem-set form))
211 (if (aggregatep parsed-type)
212 (expand-into-foreign-memory
213 value parsed-type `(inc-pointer ,ptr ,offset))
214 `(%mem-set ,(expand-to-foreign value parsed-type)
215 ,ptr ,ctype ,offset)))
216 form))
217
218 ;;;# Dereferencing Foreign Arrays
219
220 ;;; Maybe this should be named MEM-SVREF? [2007-02-28 LO]
221 (defun mem-aref (ptr type &optional (index 0))
222 "Like MEM-REF except for accessing 1d arrays."
223 (mem-ref ptr type (* index (foreign-type-size type))))
224
225 (define-compiler-macro mem-aref (&whole form ptr type &optional (index 0))
226 "Compiler macro to open-code MEM-AREF when TYPE (and eventually INDEX)."
227 (if (constantp type)
228 (if (constantp index)
229 `(mem-ref ,ptr ,type
230 ,(* (eval index) (foreign-type-size (eval type))))
231 `(mem-ref ,ptr ,type (* ,index ,(foreign-type-size (eval type)))))
232 form))
233
234 (define-setf-expander mem-aref (ptr type &optional (index 0) &environment env)
235 "SETF expander for MEM-AREF."
236 (multiple-value-bind (dummies vals newval setter getter)
237 (get-setf-expansion ptr env)
238 (declare (ignore setter newval))
239 ;; we avoid rebinding type and index, if possible (and if type is not
240 ;; constant, we don't bother about the index), so that the compiler macros
241 ;; on MEM-SET or %MEM-SET can work.
242 (with-unique-names (store type-tmp index-tmp)
243 (values
244 (append (unless (constantp type)
245 (list type-tmp))
246 (unless (and (constantp type) (constantp index))
247 (list index-tmp))
248 dummies)
249 (append (unless (constantp type)
250 (list type))
251 (unless (and (constantp type) (constantp index))
252 (list index))
253 vals)
254 (list store)
255 ;; Here we'll try to calculate the offset from the type and index,
256 ;; or if not possible at least get the type size early.
257 `(progn
258 ,(if (constantp type)
259 (if (constantp index)
260 `(mem-set ,store ,getter ,type
261 ,(* (eval index) (foreign-type-size (eval type))))
262 `(mem-set ,store ,getter ,type
263 (* ,index-tmp ,(foreign-type-size (eval type)))))
264 `(mem-set ,store ,getter ,type-tmp
265 (* ,index-tmp (foreign-type-size ,type-tmp))))
266 ,store)
267 `(mem-aref ,getter
268 ,@(if (constantp type)
269 (list type)
270 (list type-tmp))
271 ,@(if (and (constantp type) (constantp index))
272 (list index)
273 (list index-tmp)))))))
274
275 (defmethod translate-into-foreign-memory
276 (value (type foreign-pointer-type) pointer)
277 (setf (mem-aref pointer :pointer) value))
278
279 (defmethod translate-into-foreign-memory
280 (value (type foreign-built-in-type) pointer)
281 (setf (mem-aref pointer (unparse-type type)) value))
282
283 (defun mem-aptr (ptr type &optional (index 0))
284 "The pointer to the element."
285 (inc-pointer ptr (* index (foreign-type-size type))))
286
287 (define-compiler-macro mem-aptr (&whole form ptr type &optional (index 0))
288 "The pointer to the element."
289 (cond ((not (constantp type))
290 form)
291 ((not (constantp index))
292 `(inc-pointer ,ptr (* ,index ,(foreign-type-size (eval type)))))
293 ((zerop (eval index))
294 ptr)
295 (t
296 `(inc-pointer ,ptr ,(* (eval index)
297 (foreign-type-size (eval type)))))))
298
299 (define-foreign-type foreign-array-type ()
300 ((dimensions :reader dimensions :initarg :dimensions)
301 (element-type :reader element-type :initarg :element-type))
302 (:actual-type :pointer))
303
304 (defmethod aggregatep ((type foreign-array-type))
305 t)
306
307 (defmethod print-object ((type foreign-array-type) stream)
308 "Print a FOREIGN-ARRAY-TYPE instance to STREAM unreadably."
309 (print-unreadable-object (type stream :type t :identity nil)
310 (format stream "~S ~S" (element-type type) (dimensions type))))
311
312 (defun array-element-size (array-type)
313 (foreign-type-size (element-type array-type)))
314
315 (defmethod foreign-type-size ((type foreign-array-type))
316 (* (array-element-size type) (reduce #'* (dimensions type))))
317
318 (defmethod foreign-type-alignment ((type foreign-array-type))
319 (foreign-type-alignment (element-type type)))
320
321 (define-parse-method :array (element-type &rest dimensions)
322 (assert (plusp (length dimensions)))
323 (make-instance 'foreign-array-type
324 :element-type element-type
325 :dimensions dimensions))
326
327 (defun indexes-to-row-major-index (dimensions &rest subscripts)
328 (apply #'+ (maplist (lambda (x y)
329 (* (car x) (apply #'* (cdr y))))
330 subscripts
331 dimensions)))
332
333 (defun row-major-index-to-indexes (index dimensions)
334 (loop with idx = index
335 with rank = (length dimensions)
336 with indexes = (make-list rank)
337 for dim-index from (- rank 1) downto 0 do
338 (setf (values idx (nth dim-index indexes))
339 (floor idx (nth dim-index dimensions)))
340 finally (return indexes)))
341
342 (defun foreign-alloc (type &key (initial-element nil initial-element-p)
343 (initial-contents nil initial-contents-p)
344 (count 1 count-p) null-terminated-p)
345 "Allocate enough memory to hold COUNT objects of type TYPE. If
346 INITIAL-ELEMENT is supplied, each element of the newly allocated
347 memory is initialized with its value. If INITIAL-CONTENTS is supplied,
348 each of its elements will be used to initialize the contents of the
349 newly allocated memory."
350 (let (contents-length)
351 ;; Some error checking, etc...
352 (when (and null-terminated-p
353 (not (eq (canonicalize-foreign-type type) :pointer)))
354 (error "Cannot use :NULL-TERMINATED-P with non-pointer types."))
355 (when (and initial-element-p initial-contents-p)
356 (error "Cannot specify both :INITIAL-ELEMENT and :INITIAL-CONTENTS"))
357 (when initial-contents-p
358 (setq contents-length (length initial-contents))
359 (if count-p
360 (assert (>= count contents-length))
361 (setq count contents-length)))
362 ;; Everything looks good.
363 (let ((ptr (%foreign-alloc (* (foreign-type-size type)
364 (if null-terminated-p (1+ count) count)))))
365 (when initial-element-p
366 (dotimes (i count)
367 (setf (mem-aref ptr type i) initial-element)))
368 (when initial-contents-p
369 (dotimes (i contents-length)
370 (setf (mem-aref ptr type i) (elt initial-contents i))))
371 (when null-terminated-p
372 (setf (mem-aref ptr :pointer count) (null-pointer)))
373 ptr)))
374
375 ;;; Simple compiler macro that kicks in when TYPE is constant and only
376 ;;; the COUNT argument is passed. (Note: hard-coding the type's size
377 ;;; into the fasl will likely break CLISP fasl cross-platform
378 ;;; compatibilty.)
379 (define-compiler-macro foreign-alloc (&whole form type &rest args
380 &key (count 1 count-p) &allow-other-keys)
381 (if (or (and count-p (<= (length args) 2)) (null args))
382 (cond
383 ((and (constantp type) (constantp count))
384 `(%foreign-alloc ,(* (eval count) (foreign-type-size (eval type)))))
385 ((constantp type)
386 `(%foreign-alloc (* ,count ,(foreign-type-size (eval type)))))
387 (t form))
388 form))
389
390 (defun lisp-array-to-foreign (array pointer array-type)
391 "Copy elements from a Lisp array to POINTER. ARRAY-TYPE must be a CFFI array
392 type."
393 (let* ((type (ensure-parsed-base-type array-type))
394 (el-type (element-type type))
395 (dimensions (dimensions type)))
396 (loop with foreign-type-size = (array-element-size type)
397 with size = (reduce #'* dimensions)
398 for i from 0 below size
399 for offset = (* i foreign-type-size)
400 for element = (apply #'aref array
401 (row-major-index-to-indexes i dimensions))
402 do (setf (mem-ref pointer el-type offset) element))))
403
404 (defun foreign-array-to-lisp (pointer array-type &rest make-array-args)
405 "Copy elements from pointer into a Lisp array. ARRAY-TYPE must be a CFFI array
406 type; the type of the resulting Lisp array can be defined in MAKE-ARRAY-ARGS
407 that are then passed to MAKE-ARRAY. If POINTER is a null pointer, returns NIL."
408 (unless (null-pointer-p pointer)
409 (let* ((type (ensure-parsed-base-type array-type))
410 (el-type (element-type type))
411 (dimensions (dimensions type))
412 (array (apply #'make-array dimensions make-array-args)))
413 (loop with foreign-type-size = (array-element-size type)
414 with size = (reduce #'* dimensions)
415 for i from 0 below size
416 for offset = (* i foreign-type-size)
417 for element = (mem-ref pointer el-type offset)
418 do (setf (apply #'aref array
419 (row-major-index-to-indexes i dimensions))
420 element))
421 array)))
422
423 (defun foreign-array-alloc (array array-type)
424 "Allocate a foreign array containing the elements of lisp array.
425 The foreign array must be freed with foreign-array-free."
426 (check-type array array)
427 (let* ((type (ensure-parsed-base-type array-type))
428 (ptr (foreign-alloc (element-type type)
429 :count (reduce #'* (dimensions type)))))
430 (lisp-array-to-foreign array ptr array-type)
431 ptr))
432
433 (defun foreign-array-free (ptr)
434 "Free a foreign array allocated by foreign-array-alloc."
435 (foreign-free ptr))
436
437 (defmacro with-foreign-array ((var lisp-array array-type) &body body)
438 "Bind var to a foreign array containing lisp-array elements in body."
439 (with-unique-names (type)
440 `(let ((,type (ensure-parsed-base-type ,array-type)))
441 (with-foreign-pointer (,var (* (reduce #'* (dimensions ,type))
442 (array-element-size ,type)))
443 (lisp-array-to-foreign ,lisp-array ,var ,array-type)
444 ,@body))))
445
446 (defun foreign-aref (ptr array-type &rest indexes)
447 (let* ((type (ensure-parsed-base-type array-type))
448 (offset (* (array-element-size type)
449 (apply #'indexes-to-row-major-index
450 (dimensions type) indexes))))
451 (mem-ref ptr (element-type type) offset)))
452
453 (defun (setf foreign-aref) (value ptr array-type &rest indexes)
454 (let* ((type (ensure-parsed-base-type array-type))
455 (offset (* (array-element-size type)
456 (apply #'indexes-to-row-major-index
457 (dimensions type) indexes))))
458 (setf (mem-ref ptr (element-type type) offset) value)))
459
460 ;;; Automatic translations for the :ARRAY type. Notice that these
461 ;;; translators will also invoke the appropriate translators for for
462 ;;; each of the array's elements since that's the normal behaviour of
463 ;;; the FOREIGN-ARRAY-* operators, but there's a FIXME: **it doesn't
464 ;;; free them yet**
465
466 ;;; This used to be in a separate type but let's experiment with just
467 ;;; one type for a while. [2008-12-30 LO]
468
469 ;;; FIXME: those ugly invocations of UNPARSE-TYPE suggest that these
470 ;;; foreign array operators should take the type and dimention
471 ;;; arguments "unboxed". [2008-12-31 LO]
472
473 (defmethod translate-to-foreign (array (type foreign-array-type))
474 (foreign-array-alloc array (unparse-type type)))
475
476 (defmethod translate-aggregate-to-foreign (ptr value (type foreign-array-type))
477 (lisp-array-to-foreign value ptr (unparse-type type)))
478
479 (defmethod translate-from-foreign (pointer (type foreign-array-type))
480 (foreign-array-to-lisp pointer (unparse-type type)))
481
482 (defmethod free-translated-object (pointer (type foreign-array-type) param)
483 (declare (ignore param))
484 (foreign-array-free pointer))
485
486 ;;;# Foreign Structures
487
488 ;;;## Foreign Structure Slots
489
490 (defgeneric foreign-struct-slot-pointer (ptr slot)
491 (:documentation
492 "Get the address of SLOT relative to PTR."))
493
494 (defgeneric foreign-struct-slot-pointer-form (ptr slot)
495 (:documentation
496 "Return a form to get the address of SLOT in PTR."))
497
498 (defgeneric foreign-struct-slot-value (ptr slot)
499 (:documentation
500 "Return the value of SLOT in structure PTR."))
501
502 (defgeneric (setf foreign-struct-slot-value) (value ptr slot)
503 (:documentation
504 "Set the value of a SLOT in structure PTR."))
505
506 (defgeneric foreign-struct-slot-value-form (ptr slot)
507 (:documentation
508 "Return a form to get the value of SLOT in struct PTR."))
509
510 (defgeneric foreign-struct-slot-set-form (value ptr slot)
511 (:documentation
512 "Return a form to set the value of SLOT in struct PTR."))
513
514 (defclass foreign-struct-slot ()
515 ((name :initarg :name :reader slot-name)
516 (offset :initarg :offset :accessor slot-offset)
517 ;; FIXME: the type should probably be parsed?
518 (type :initarg :type :accessor slot-type))
519 (:documentation "Base class for simple and aggregate slots."))
520
521 (defmethod foreign-struct-slot-pointer (ptr (slot foreign-struct-slot))
522 "Return the address of SLOT relative to PTR."
523 (inc-pointer ptr (slot-offset slot)))
524
525 (defmethod foreign-struct-slot-pointer-form (ptr (slot foreign-struct-slot))
526 "Return a form to get the address of SLOT relative to PTR."
527 (let ((offset (slot-offset slot)))
528 (if (zerop offset)
529 ptr
530 `(inc-pointer ,ptr ,offset))))
531
532 (defun foreign-slot-names (type)
533 "Returns a list of TYPE's slot names in no particular order."
534 (loop for value being the hash-values
535 in (slots (ensure-parsed-base-type type))
536 collect (slot-name value)))
537
538 ;;;### Simple Slots
539
540 (defclass simple-struct-slot (foreign-struct-slot)
541 ()
542 (:documentation "Non-aggregate structure slots."))
543
544 (defmethod foreign-struct-slot-value (ptr (slot simple-struct-slot))
545 "Return the value of a simple SLOT from a struct at PTR."
546 (mem-ref ptr (slot-type slot) (slot-offset slot)))
547
548 (defmethod foreign-struct-slot-value-form (ptr (slot simple-struct-slot))
549 "Return a form to get the value of a slot from PTR."
550 `(mem-ref ,ptr ',(slot-type slot) ,(slot-offset slot)))
551
552 (defmethod (setf foreign-struct-slot-value) (value ptr (slot simple-struct-slot))
553 "Set the value of a simple SLOT to VALUE in PTR."
554 (setf (mem-ref ptr (slot-type slot) (slot-offset slot)) value))
555
556 (defmethod foreign-struct-slot-set-form (value ptr (slot simple-struct-slot))
557 "Return a form to set the value of a simple structure slot."
558 `(setf (mem-ref ,ptr ',(slot-type slot) ,(slot-offset slot)) ,value))
559
560 ;;;### Aggregate Slots
561
562 (defclass aggregate-struct-slot (foreign-struct-slot)
563 ((count :initarg :count :accessor slot-count))
564 (:documentation "Aggregate structure slots."))
565
566 ;;; Since MEM-REF returns a pointer for struct types we are able to
567 ;;; chain together slot names when accessing slot values in nested
568 ;;; structures.
569 (defmethod foreign-struct-slot-value (ptr (slot aggregate-struct-slot))
570 "Return a pointer to SLOT relative to PTR."
571 (convert-from-foreign (inc-pointer ptr (slot-offset slot))
572 (slot-type slot)))
573
574 (defmethod foreign-struct-slot-value-form (ptr (slot aggregate-struct-slot))
575 "Return a form to get the value of SLOT relative to PTR."
576 `(convert-from-foreign (inc-pointer ,ptr ,(slot-offset slot))
577 ',(slot-type slot)))
578
579 (defmethod translate-aggregate-to-foreign (ptr value (type foreign-struct-type))
580 ;;; FIXME: use the block memory interface instead.
581 (loop for i below (foreign-type-size type)
582 do (%mem-set (%mem-ref value :char i) ptr :char i)))
583
584 (defmethod (setf foreign-struct-slot-value)
585 (value ptr (slot aggregate-struct-slot))
586 "Set the value of an aggregate SLOT to VALUE in PTR."
587 (translate-aggregate-to-foreign (inc-pointer ptr (slot-offset slot))
588 value
589 (parse-type (slot-type slot))))
590
591 (defmethod foreign-struct-slot-set-form (value ptr (slot aggregate-struct-slot))
592 "Return a form to get the value of an aggregate SLOT relative to PTR."
593 `(translate-aggregate-to-foreign (inc-pointer ,ptr ,(slot-offset slot))
594 ,value
595 ,(parse-type (slot-type slot))))
596
597 ;;;## Defining Foreign Structures
598
599 (defun make-struct-slot (name offset type count)
600 "Make the appropriate type of structure slot."
601 ;; If TYPE is an aggregate type or COUNT is >1, create an
602 ;; AGGREGATE-STRUCT-SLOT, otherwise a SIMPLE-STRUCT-SLOT.
603 (if (or (> count 1) (aggregatep (parse-type type)))
604 (make-instance 'aggregate-struct-slot :offset offset :type type
605 :name name :count count)
606 (make-instance 'simple-struct-slot :offset offset :type type
607 :name name)))
608
609 (defun parse-deprecated-struct-type (name struct-or-union)
610 (check-type struct-or-union (member :struct :union))
611 (let* ((struct-type-name `(,struct-or-union ,name))
612 (struct-type (parse-type struct-type-name)))
613 (simple-style-warning
614 "bare references to struct types are deprecated. ~
615 Please use ~S or ~S instead."
616 `(:pointer ,struct-type-name) struct-type-name)
617 (make-instance (class-of struct-type)
618 :alignment (alignment struct-type)
619 :size (size struct-type)
620 :slots (slots struct-type)
621 :name (name struct-type)
622 :bare t)))
623
624 ;;; Regarding structure alignment, the following ABIs were checked:
625 ;;; - System-V ABI: x86, x86-64, ppc, arm, mips and itanium. (more?)
626 ;;; - Mac OS X ABI Function Call Guide: ppc32, ppc64 and x86.
627 ;;;
628 ;;; Rules used here:
629 ;;;
630 ;;; 1. "An entire structure or union object is aligned on the same
631 ;;; boundary as its most strictly aligned member."
632 ;;;
633 ;;; 2. "Each member is assigned to the lowest available offset with
634 ;;; the appropriate alignment. This may require internal
635 ;;; padding, depending on the previous member."
636 ;;;
637 ;;; 3. "A structure's size is increased, if necessary, to make it a
638 ;;; multiple of the alignment. This may require tail padding,
639 ;;; depending on the last member."
640 ;;;
641 ;;; Special cases from darwin/ppc32's ABI:
642 ;;; http://developer.apple.com/documentation/DeveloperTools/Conceptual/LowLevelABI/index.html
643 ;;;
644 ;;; 4. "The embedding alignment of the first element in a data
645 ;;; structure is equal to the element's natural alignment."
646 ;;;
647 ;;; 5. "For subsequent elements that have a natural alignment
648 ;;; greater than 4 bytes, the embedding alignment is 4, unless
649 ;;; the element is a vector." (note: this applies for
650 ;;; structures too)
651
652 ;; FIXME: get a better name for this. --luis
653 (defun get-alignment (type alignment-type firstp)
654 "Return alignment for TYPE according to ALIGNMENT-TYPE."
655 (declare (ignorable firstp))
656 (ecase alignment-type
657 (:normal #-(and darwin ppc)
658 (foreign-type-alignment type)
659 #+(and darwin ppc)
660 (if firstp
661 (foreign-type-alignment type)
662 (min 4 (foreign-type-alignment type))))))
663
664 (defun adjust-for-alignment (type offset alignment-type firstp)
665 "Return OFFSET aligned properly for TYPE according to ALIGNMENT-TYPE."
666 (let* ((align (get-alignment type alignment-type firstp))
667 (rem (mod offset align)))
668 (if (zerop rem)
669 offset
670 (+ offset (- align rem)))))
671
672 (defmacro with-tentative-type-definition ((name value namespace) &body body)
673 (once-only (name namespace)
674 `(unwind-protect-case ()
675 (progn
676 (notice-foreign-type ,name ,value ,namespace)
677 ,@body)
678 (:abort (undefine-foreign-type ,name ,namespace)))))
679
680 (defun notice-foreign-struct-definition (name options slots)
681 "Parse and install a foreign structure definition."
682 (destructuring-bind (&key size (class 'foreign-struct-type))
683 options
684 (let ((struct (make-instance class :name name))
685 (current-offset 0)
686 (max-align 1)
687 (firstp t))
688 (with-tentative-type-definition (name struct :struct)
689 ;; determine offsets
690 (dolist (slotdef slots)
691 (destructuring-bind (slotname type &key (count 1) offset) slotdef
692 (when (eq (canonicalize-foreign-type type) :void)
693 (simple-foreign-type-error type :struct
694 "In struct ~S: void type not allowed in field ~S"
695 name slotdef))
696 (setq current-offset
697 (or offset
698 (adjust-for-alignment type current-offset :normal firstp)))
699 (let* ((slot (make-struct-slot slotname current-offset type count))
700 (align (get-alignment (slot-type slot) :normal firstp)))
701 (setf (gethash slotname (slots struct)) slot)
702 (when (> align max-align)
703 (setq max-align align)))
704 (incf current-offset (* count (foreign-type-size type))))
705 (setq firstp nil))
706 ;; calculate padding and alignment
707 (setf (alignment struct) max-align) ; See point 1 above.
708 (let ((tail-padding (- max-align (rem current-offset max-align))))
709 (unless (= tail-padding max-align) ; See point 3 above.
710 (incf current-offset tail-padding)))
711 (setf (size struct) (or size current-offset))))))
712
713 (defun generate-struct-accessors (name conc-name slot-names)
714 (loop with pointer-arg = (symbolicate '#:pointer-to- name)
715 for slot in slot-names
716 for accessor = (symbolicate conc-name slot)
717 collect `(defun ,accessor (,pointer-arg)
718 (foreign-slot-value ,pointer-arg '(:struct ,name) ',slot))
719 collect `(defun (setf ,accessor) (value ,pointer-arg)
720 (foreign-slot-set value ,pointer-arg '(:struct ,name) ',slot))))
721
722 (define-parse-method :struct (name)
723 (funcall (find-type-parser name :struct)))
724
725 (defvar *defcstruct-hook* nil)
726
727 (defmacro defcstruct (name-and-options &body fields)
728 "Define the layout of a foreign structure."
729 (discard-docstring fields)
730 (destructuring-bind (name . options)
731 (ensure-list name-and-options)
732 (let ((conc-name (getf options :conc-name)))
733 (remf options :conc-name)
734 (unless (getf options :class) (setf (getf options :class) (symbolicate name '-tclass)))
735 `(eval-when (:compile-toplevel :load-toplevel :execute)
736 ;; m-f-s-t could do with this with mop:ensure-class.
737 ,(when-let (class (getf options :class))
738 `(defclass ,class (foreign-struct-type
739 translatable-foreign-type)
740 ()))
741 (notice-foreign-struct-definition ',name ',options ',fields)
742 ,@(when conc-name
743 (generate-struct-accessors name conc-name
744 (mapcar #'car fields)))
745 ,@(when *defcstruct-hook*
746 ;; If non-nil, *defcstruct-hook* should be a function
747 ;; of the arguments that returns NIL or a list of
748 ;; forms to include in the expansion.
749 (apply *defcstruct-hook* name-and-options fields))
750 (define-parse-method ,name ()
751 (parse-deprecated-struct-type ',name :struct))
752 '(:struct ,name)))))
753
754 ;;;## Accessing Foreign Structure Slots
755
756 (defun get-slot-info (type slot-name)
757 "Return the slot info for SLOT-NAME or raise an error."
758 (let* ((struct (ensure-parsed-base-type type))
759 (info (gethash slot-name (slots struct))))
760 (unless info
761 (simple-foreign-type-error type :struct
762 "Undefined slot ~A in foreign type ~A."
763 slot-name type))
764 info))
765
766 (defun foreign-slot-pointer (ptr type slot-name)
767 "Return the address of SLOT-NAME in the structure at PTR."
768 (foreign-struct-slot-pointer ptr (get-slot-info type slot-name)))
769
770 (define-compiler-macro foreign-slot-pointer (&whole whole ptr type slot-name)
771 (if (and (constantp type) (constantp slot-name))
772 (foreign-struct-slot-pointer-form
773 ptr (get-slot-info (eval type) (eval slot-name)))
774 whole))
775
776 (defun foreign-slot-type (type slot-name)
777 "Return the type of SLOT in a struct TYPE."
778 (slot-type (get-slot-info type slot-name)))
779
780 (defun foreign-slot-offset (type slot-name)
781 "Return the offset of SLOT in a struct TYPE."
782 (slot-offset (get-slot-info type slot-name)))
783
784 (defun foreign-slot-count (type slot-name)
785 "Return the number of items in SLOT in a struct TYPE."
786 (slot-count (get-slot-info type slot-name)))
787
788 (defun foreign-slot-value (ptr type slot-name)
789 "Return the value of SLOT-NAME in the foreign structure at PTR."
790 (foreign-struct-slot-value ptr (get-slot-info type slot-name)))
791
792 (define-compiler-macro foreign-slot-value (&whole form ptr type slot-name)
793 "Optimizer for FOREIGN-SLOT-VALUE when TYPE is constant."
794 (if (and (constantp type) (constantp slot-name))
795 (foreign-struct-slot-value-form
796 ptr (get-slot-info (eval type) (eval slot-name)))
797 form))
798
799 (define-setf-expander foreign-slot-value (ptr type slot-name &environment env)
800 "SETF expander for FOREIGN-SLOT-VALUE."
801 (multiple-value-bind (dummies vals newval setter getter)
802 (get-setf-expansion ptr env)
803 (declare (ignore setter newval))
804 (if (and (constantp type) (constantp slot-name))
805 ;; if TYPE and SLOT-NAME are constant we avoid rebinding them
806 ;; so that the compiler macro on FOREIGN-SLOT-SET works.
807 (with-unique-names (store)
808 (values
809 dummies
810 vals
811 (list store)
812 `(progn
813 (foreign-slot-set ,store ,getter ,type ,slot-name)
814 ,store)
815 `(foreign-slot-value ,getter ,type ,slot-name)))
816 ;; if not...
817 (with-unique-names (store slot-name-tmp type-tmp)
818 (values
819 (list* type-tmp slot-name-tmp dummies)
820 (list* type slot-name vals)
821 (list store)
822 `(progn
823 (foreign-slot-set ,store ,getter ,type-tmp ,slot-name-tmp)
824 ,store)
825 `(foreign-slot-value ,getter ,type-tmp ,slot-name-tmp))))))
826
827 (defun foreign-slot-set (value ptr type slot-name)
828 "Set the value of SLOT-NAME in a foreign structure."
829 (setf (foreign-struct-slot-value ptr (get-slot-info type slot-name)) value))
830
831 (define-compiler-macro foreign-slot-set
832 (&whole form value ptr type slot-name)
833 "Optimizer when TYPE and SLOT-NAME are constant."
834 (if (and (constantp type) (constantp slot-name))
835 (foreign-struct-slot-set-form
836 value ptr (get-slot-info (eval type) (eval slot-name)))
837 form))
838
839 (defmacro with-foreign-slots ((vars ptr type) &body body)
840 "Create local symbol macros for each var in VARS to reference
841 foreign slots in PTR of TYPE. Similar to WITH-SLOTS.
842 Each var can be of the form: slot-name - in which case slot-name will
843 be bound to the value of the slot or: (:pointer slot-name) - in which
844 case slot-name will be bound to the pointer to that slot."
845 (let ((ptr-var (gensym "PTR")))
846 `(let ((,ptr-var ,ptr))
847 (symbol-macrolet
848 ,(loop :for var :in vars
849 :collect
850 (if (listp var)
851 (if (eq (first var) :pointer)
852 `(,(second var) (foreign-slot-pointer
853 ,ptr-var ',type ',(second var)))
854 (error
855 "Malformed slot specification ~a; must be:`name' or `(:pointer name)'"
856 var))
857 `(,var (foreign-slot-value ,ptr-var ',type ',var))))
858 ,@body))))
859
860 ;;; We could add an option to define a struct instead of a class, in
861 ;;; the unlikely event someone needs something like that.
862 (defmacro define-c-struct-wrapper (class-and-type supers &optional slots)
863 "Define a new class with CLOS slots matching those of a foreign
864 struct type. An INITIALIZE-INSTANCE method is defined which
865 takes a :POINTER initarg that is used to store the slots of a
866 foreign object. This pointer is only used for initialization and
867 it is not retained.
868
869 CLASS-AND-TYPE is either a list of the form (class-name
870 struct-type) or a single symbol naming both. The class will
871 inherit SUPERS. If a list of SLOTS is specified, only those
872 slots will be defined and stored."
873 (destructuring-bind (class-name &optional (struct-type (list :struct class-name)))
874 (ensure-list class-and-type)
875 (let ((slots (or slots (foreign-slot-names struct-type))))
876 `(progn
877 (defclass ,class-name ,supers
878 ,(loop for slot in slots collect
879 `(,slot :reader ,(format-symbol t "~A-~A" class-name slot))))
880 ;; This could be done in a parent class by using
881 ;; FOREIGN-SLOT-NAMES when instantiating but then the compiler
882 ;; macros wouldn't kick in.
883 (defmethod initialize-instance :after ((inst ,class-name) &key pointer)
884 (with-foreign-slots (,slots pointer ,struct-type)
885 ,@(loop for slot in slots collect
886 `(setf (slot-value inst ',slot) ,slot))))
887 ',class-name))))
888
889 ;;;# Foreign Unions
890 ;;;
891 ;;; A union is a subclass of FOREIGN-STRUCT-TYPE in which all slots
892 ;;; have an offset of zero.
893
894 ;;; See also the notes regarding ABI requirements in
895 ;;; NOTICE-FOREIGN-STRUCT-DEFINITION
896 (defun notice-foreign-union-definition (name-and-options slots)
897 "Parse and install a foreign union definition."
898 (destructuring-bind (name &key size)
899 (ensure-list name-and-options)
900 (let ((union (make-instance 'foreign-union-type :name name))
901 (max-size 0)
902 (max-align 0))
903 (with-tentative-type-definition (name union :union)
904 (dolist (slotdef slots)
905 (destructuring-bind (slotname type &key (count 1)) slotdef
906 (when (eq (canonicalize-foreign-type type) :void)
907 (simple-foreign-type-error name :struct
908 "In union ~S: void type not allowed in field ~S"
909 name slotdef))
910 (let* ((slot (make-struct-slot slotname 0 type count))
911 (size (* count (foreign-type-size type)))
912 (align (foreign-type-alignment (slot-type slot))))
913 (setf (gethash slotname (slots union)) slot)
914 (when (> size max-size)
915 (setf max-size size))
916 (when (> align max-align)
917 (setf max-align align)))))
918 (setf (size union) (or size max-size))
919 (setf (alignment union) max-align)))))
920
921 (define-parse-method :union (name)
922 (funcall (find-type-parser name :union)))
923
924 (defmacro defcunion (name-and-options &body fields)
925 "Define the layout of a foreign union."
926 (discard-docstring fields)
927 (destructuring-bind (name &key size)
928 (ensure-list name-and-options)
929 (declare (ignore size))
930 `(eval-when (:compile-toplevel :load-toplevel :execute)
931 (notice-foreign-union-definition ',name-and-options ',fields)
932 (define-parse-method ,name ()
933 (parse-deprecated-struct-type ',name :union))
934 '(:union ,name))))
935
936 ;;;# Operations on Types
937
938 (defmethod foreign-type-alignment (type)
939 "Return the alignment in bytes of a foreign type."
940 (foreign-type-alignment (parse-type type)))
941
942 (defmacro with-foreign-object ((var type &optional (count 1)) &body body)
943 "Bind VAR to a pointer to COUNT objects of TYPE during BODY.
944 The buffer has dynamic extent and may be stack allocated."
945 `(with-foreign-pointer
946 (,var ,(if (constantp type)
947 ;; with-foreign-pointer may benefit from constant folding:
948 (if (constantp count)
949 (* (eval count) (foreign-type-size (eval type)))
950 `(* ,count ,(foreign-type-size (eval type))))
951 `(* ,count (foreign-type-size ,type))))
952 ,@body))
953
954 (defmacro with-foreign-objects (bindings &body body)
955 (if bindings
956 `(with-foreign-object ,(car bindings)
957 (with-foreign-objects ,(cdr bindings)
958 ,@body))
959 `(progn ,@body)))
960
961 ;;;## Anonymous Type Translators
962 ;;;
963 ;;; (:wrapper :to-c some-function :from-c another-function)
964 ;;;
965 ;;; TODO: We will need to add a FREE function to this as well I think.
966 ;;; --james
967
968 (define-foreign-type foreign-type-wrapper ()
969 ((to-c :initarg :to-c :reader wrapper-to-c)
970 (from-c :initarg :from-c :reader wrapper-from-c))
971 (:documentation "Wrapper type."))
972
973 (define-parse-method :wrapper (base-type &key to-c from-c)
974 (make-instance 'foreign-type-wrapper
975 :actual-type (parse-type base-type)
976 :to-c (or to-c 'identity)
977 :from-c (or from-c 'identity)))
978
979 (defmethod translate-to-foreign (value (type foreign-type-wrapper))
980 (translate-to-foreign
981 (funcall (slot-value type 'to-c) value) (actual-type type)))
982
983 (defmethod translate-from-foreign (value (type foreign-type-wrapper))
984 (funcall (slot-value type 'from-c)
985 (translate-from-foreign value (actual-type type))))
986
987 ;;;# Other types
988
989 ;;; Boolean type. Maps to an :int by default. Only accepts integer types.
990 (define-foreign-type foreign-boolean-type ()
991 ())
992
993 (define-parse-method :boolean (&optional (base-type :int))
994 (make-instance
995 'foreign-boolean-type :actual-type
996 (ecase (canonicalize-foreign-type base-type)
997 ((:char :unsigned-char :int :unsigned-int :long :unsigned-long
998 #-cffi-sys::no-long-long :long-long
999 #-cffi-sys::no-long-long :unsigned-long-long) base-type))))
1000
1001 (defmethod translate-to-foreign (value (type foreign-boolean-type))
1002 (if value 1 0))
1003
1004 (defmethod translate-from-foreign (value (type foreign-boolean-type))
1005 (not (zerop value)))
1006
1007 (defmethod expand-to-foreign (value (type foreign-boolean-type))
1008 "Optimization for the :boolean type."
1009 (if (constantp value)
1010 (if (eval value) 1 0)
1011 `(if ,value 1 0)))
1012
1013 (defmethod expand-from-foreign (value (type foreign-boolean-type))
1014 "Optimization for the :boolean type."
1015 (if (constantp value) ; very unlikely, heh
1016 (not (zerop (eval value)))
1017 `(not (zerop ,value))))
1018
1019 ;;; Boolean type that represents C99 _Bool
1020 (defctype :bool (:boolean :char))
1021
1022 ;;;# Typedefs for built-in types.
1023
1024 (defctype :uchar :unsigned-char)
1025 (defctype :ushort :unsigned-short)
1026 (defctype :uint :unsigned-int)
1027 (defctype :ulong :unsigned-long)
1028 (defctype :llong :long-long)
1029 (defctype :ullong :unsigned-long-long)
1030
1031 ;;; We try to define the :[u]int{8,16,32,64} types by looking at
1032 ;;; the sizes of the built-in integer types and defining typedefs.
1033 (eval-when (:compile-toplevel :load-toplevel :execute)
1034 (macrolet
1035 ((match-types (sized-types mtypes)
1036 `(progn
1037 ,@(loop for (type . size-or-type) in sized-types
1038 for m = (car (member (if (keywordp size-or-type)
1039 (foreign-type-size size-or-type)
1040 size-or-type)
1041 mtypes :key #'foreign-type-size))
1042 when m collect `(defctype ,type ,m)))))
1043 ;; signed
1044 (match-types ((:int8 . 1) (:int16 . 2) (:int32 . 4) (:int64 . 8)
1045 (:intptr . :pointer))
1046 (:char :short :int :long :long-long))
1047 ;; unsigned
1048 (match-types ((:uint8 . 1) (:uint16 . 2) (:uint32 . 4) (:uint64 . 8)
1049 (:uintptr . :pointer))
1050 (:unsigned-char :unsigned-short :unsigned-int :unsigned-long
1051 :unsigned-long-long))))