1 ;;;; This file contains parts of the ALIEN implementation that
2 ;;;; are not part of the compiler.
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
13 (in-package "SB!ALIEN")
20 ;;; Make a string out of the symbol, converting all uppercase letters to
21 ;;; lower case and hyphens into underscores.
22 (eval-when (:compile-toplevel :load-toplevel :execute)
23 (defun guess-alien-name-from-lisp-name (lisp-name)
24 (declare (type symbol lisp-name))
25 (nsubstitute #\_ #\- (string-downcase (symbol-name lisp-name)))))
27 ;;; The opposite of GUESS-ALIEN-NAME-FROM-LISP-NAME. Make a symbol out
28 ;;; of the string, converting all lowercase letters to uppercase and
29 ;;; underscores into hyphens.
30 (eval-when (:compile-toplevel :load-toplevel :execute)
31 (defun guess-lisp-name-from-alien-name (alien-name)
32 (declare (type simple-string alien-name))
33 (intern (nsubstitute #\- #\_ (string-upcase alien-name)))))
35 ;;; Extract the Lisp and alien names from NAME. If only one is given,
37 (eval-when (:compile-toplevel :load-toplevel :execute)
38 (defun pick-lisp-and-alien-names (name)
41 (values (guess-lisp-name-from-alien-name name) name))
43 (values name (guess-alien-name-from-lisp-name name)))
45 (unless (proper-list-of-length-p name 2)
46 (error "badly formed alien name"))
47 (values (cadr name) (car name))))))
49 (defmacro def-alien-variable (name type &environment env)
51 "Define NAME as an external alien variable of type TYPE. NAME should be
52 a list of a string holding the alien name and a symbol to use as the Lisp
53 name. If NAME is just a symbol or string, then the other name is guessed
54 from the one supplied."
55 (multiple-value-bind (lisp-name alien-name) (pick-lisp-and-alien-names name)
56 (with-auxiliary-alien-types env
57 (let ((alien-type (parse-alien-type type env)))
58 `(eval-when (:compile-toplevel :load-toplevel :execute)
59 ,@(when *new-auxiliary-types*
60 `((%def-auxiliary-alien-types ',*new-auxiliary-types*)))
61 (%def-alien-variable ',lisp-name
65 ;;; Do the actual work of DEF-ALIEN-VARIABLE.
66 (eval-when (:compile-toplevel :load-toplevel :execute)
67 (defun %def-alien-variable (lisp-name alien-name type)
68 (setf (info :variable :kind lisp-name) :alien)
69 (setf (info :variable :where-from lisp-name) :defined)
70 (clear-info :variable :constant-value lisp-name)
71 (setf (info :variable :alien-info lisp-name)
72 (make-heap-alien-info :type type
73 :sap-form `(foreign-symbol-address
76 (defmacro extern-alien (name type &environment env)
78 "Access the alien variable named NAME, assuming it is of type TYPE. This
80 (let ((alien-name (etypecase name
81 (symbol (guess-alien-name-from-lisp-name name))
83 `(%heap-alien ',(make-heap-alien-info
84 :type (parse-alien-type type env)
85 :sap-form `(foreign-symbol-address ',alien-name)))))
87 (defmacro with-alien (bindings &body body &environment env)
89 "Establish some local alien variables. Each BINDING is of the form:
90 VAR TYPE [ ALLOCATION ] [ INITIAL-VALUE | EXTERNAL-NAME ]
91 ALLOCATION should be one of:
93 The alien is allocated on the stack, and has dynamic extent.
95 The alien is allocated on the heap, and has infinite extent. The alien
96 is allocated at load time, so the same piece of memory is used each time
99 No alien is allocated, but VAR is established as a local name for
100 the external alien given by EXTERNAL-NAME."
101 (with-auxiliary-alien-types env
102 (dolist (binding (reverse bindings))
104 (symbol type &optional (opt1 nil opt1p) (opt2 nil opt2p))
106 (let ((alien-type (parse-alien-type type env)))
107 (multiple-value-bind (allocation initial-value)
112 (values opt1 (guess-alien-name-from-lisp-name symbol)))
116 (values :local opt1))))
122 (make-symbol (concatenate 'string "SAP-FOR-"
123 (symbol-name symbol)))))
124 `((let ((,sap (load-time-value (%make-alien ...))))
125 (declare (type system-area-pointer ,sap))
127 ((,symbol (sap-alien ,sap ,type)))
128 ,@(when initial-value
129 `((setq ,symbol ,initial-value)))
132 (let ((info (make-heap-alien-info
134 :sap-form `(foreign-symbol-address
137 ((,symbol (%heap-alien ',info)))
141 (initval (if initial-value (gensym)))
142 (info (make-local-alien-info :type alien-type)))
143 `((let ((,var (make-local-alien ',info))
144 ,@(when initial-value
145 `((,initval ,initial-value))))
146 (note-local-alien-type ',info ,var)
147 (multiple-value-prog1
149 ((,symbol (local-alien ',info ,var)))
150 ,@(when initial-value
151 `((setq ,symbol ,initval)))
153 (dispose-local-alien ',info ,var))))))))))))
154 (verify-local-auxiliaries-okay)
155 `(symbol-macrolet ((&auxiliary-type-definitions&
156 ,(append *new-auxiliary-types*
157 (auxiliary-type-definitions env))))
160 ;;;; runtime C values that don't correspond directly to Lisp types
164 ;;; Note: The DEFSTRUCT for ALIEN-VALUE lives in a separate file
165 ;;; 'cause it has to be real early in the cold-load order.
166 #!-sb-fluid (declaim (freeze-type alien-value))
167 (def!method print-object ((value alien-value) stream)
168 (print-unreadable-object (value stream)
172 (sap-int (alien-value-sap value)))))
174 #!-sb-fluid (declaim (inline null-alien))
175 (defun null-alien (x)
177 "Return true if X (which must be an ALIEN pointer) is null, false otherwise."
178 (zerop (sap-int (alien-sap x))))
180 (defmacro sap-alien (sap type &environment env)
182 "Convert the system area pointer SAP to an ALIEN of the specified TYPE (not
183 evaluated.) TYPE must be pointer-like."
184 (let ((alien-type (parse-alien-type type env)))
185 (if (eq (compute-alien-rep-type alien-type) 'system-area-pointer)
186 `(%sap-alien ,sap ',alien-type)
187 (error "cannot make aliens of type ~S out of SAPs" type))))
189 (defun %sap-alien (sap type)
190 (declare (type system-area-pointer sap)
191 (type alien-type type))
192 (make-alien-value :sap sap :type type))
194 (defun alien-sap (alien)
196 "Return a System-Area-Pointer pointing to Alien's data."
197 (declare (type alien-value alien))
198 (alien-value-sap alien))
200 ;;;; allocation/deallocation of heap aliens
202 (defmacro make-alien (type &optional size &environment env)
204 "Allocate an alien of type TYPE and return an alien pointer to it. If SIZE
205 is supplied, how it is interpreted depends on TYPE. If TYPE is an array
206 type, SIZE is used as the first dimension for the allocated array. If TYPE
207 is not an array, then SIZE is the number of elements to allocate. The
208 memory is allocated using ``malloc'', so it can be passed to foreign
209 functions which use ``free''."
210 (let ((alien-type (if (alien-type-p type)
212 (parse-alien-type type env))))
213 (multiple-value-bind (size-expr element-type)
214 (if (alien-array-type-p alien-type)
215 (let ((dims (alien-array-type-dimensions alien-type)))
220 "cannot override the size of zero-dimensional arrays"))
221 (when (constantp size)
222 (setf alien-type (copy-alien-array-type alien-type))
223 (setf (alien-array-type-dimensions alien-type)
224 (cons (eval size) (cdr dims)))))
226 (setf size (car dims)))
229 (values `(* ,size ,@(cdr dims))
230 (alien-array-type-element-type alien-type)))
231 (values (or size 1) alien-type))
232 (let ((bits (alien-type-bits element-type))
233 (alignment (alien-type-alignment element-type)))
235 (error "The size of ~S is unknown."
236 (unparse-alien-type element-type)))
238 (error "The alignment of ~S is unknown."
239 (unparse-alien-type element-type)))
240 `(%sap-alien (%make-alien (* ,(align-offset bits alignment)
242 ',(make-alien-pointer-type :to alien-type))))))
244 ;;; Allocate a block of memory at least BITS bits long and return a
245 ;;; system area pointer to it.
246 #!-sb-fluid (declaim (inline %make-alien))
247 (defun %make-alien (bits)
248 (declare (type sb!kernel:index bits) (optimize-interface (safety 2)))
249 (alien-funcall (extern-alien "malloc" (function system-area-pointer unsigned))
250 (ash (the sb!kernel:index (+ bits 7)) -3)))
252 #!-sb-fluid (declaim (inline free-alien))
253 (defun free-alien (alien)
255 "Dispose of the storage pointed to by ALIEN. ALIEN must have been allocated
256 by MAKE-ALIEN or ``malloc''."
257 (alien-funcall (extern-alien "free" (function (values) system-area-pointer))
261 ;;;; the SLOT operator
263 ;;; Find the field named SLOT, or die trying.
264 (defun slot-or-lose (type slot)
265 (declare (type alien-record-type type)
267 (or (find slot (alien-record-type-fields type)
268 :key #'alien-record-field-name)
269 (error "There is no slot named ~S in ~S" slot type)))
271 ;;; Extract the value from the named slot from the record ALIEN. If
272 ;;; ALIEN is actually a pointer, then DEREF it first.
273 (defun slot (alien slot)
275 "Extract SLOT from the Alien STRUCT or UNION ALIEN. May be set with SETF."
276 (declare (type alien-value alien)
278 (optimize (inhibit-warnings 3)))
279 (let ((type (alien-value-type alien)))
282 (slot (deref alien) slot))
284 (let ((field (slot-or-lose type slot)))
285 (extract-alien-value (alien-value-sap alien)
286 (alien-record-field-offset field)
287 (alien-record-field-type field)))))))
289 ;;; Deposit the value in the specified slot of the record ALIEN. If
290 ;;; the ALIEN is really a pointer, DEREF it first. The compiler uses
291 ;;; this when it can't figure out anything better.
292 (defun %set-slot (alien slot value)
293 (declare (type alien-value alien)
295 (optimize (inhibit-warnings 3)))
296 (let ((type (alien-value-type alien)))
299 (%set-slot (deref alien) slot value))
301 (let ((field (slot-or-lose type slot)))
302 (deposit-alien-value (alien-value-sap alien)
303 (alien-record-field-offset field)
304 (alien-record-field-type field)
307 ;;; Compute the address of the specified slot and return a pointer to it.
308 (defun %slot-addr (alien slot)
309 (declare (type alien-value alien)
311 (optimize (inhibit-warnings 3)))
312 (let ((type (alien-value-type alien)))
315 (%slot-addr (deref alien) slot))
317 (let* ((field (slot-or-lose type slot))
318 (offset (alien-record-field-offset field))
319 (field-type (alien-record-field-type field)))
320 (%sap-alien (sap+ (alien-sap alien) (/ offset sb!vm:byte-bits))
321 (make-alien-pointer-type :to field-type)))))))
323 ;;;; the DEREF operator
325 ;;; Does most of the work of the different DEREF methods. Returns two values:
326 ;;; the type and the offset (in bits) of the refered to alien.
327 (defun deref-guts (alien indices)
328 (declare (type alien-value alien)
330 (values alien-type integer))
331 (let ((type (alien-value-type alien)))
335 (error "too many indices when derefing ~S: ~D"
338 (let ((element-type (alien-pointer-type-to type)))
341 (* (align-offset (alien-type-bits element-type)
342 (alien-type-alignment element-type))
346 (unless (= (length indices) (length (alien-array-type-dimensions type)))
347 (error "incorrect number of indices when derefing ~S: ~D"
348 type (length indices)))
349 (labels ((frob (dims indices offset)
352 (frob (cdr dims) (cdr indices)
353 (+ (if (zerop offset)
355 (* offset (car dims)))
357 (let ((element-type (alien-array-type-element-type type)))
359 (* (align-offset (alien-type-bits element-type)
360 (alien-type-alignment element-type))
361 (frob (alien-array-type-dimensions type)
364 ;;; Dereference the alien and return the results.
365 (defun deref (alien &rest indices)
367 "De-reference an Alien pointer or array. If an array, the indices are used
368 as the indices of the array element to access. If a pointer, one index can
369 optionally be specified, giving the equivalent of C pointer arithmetic."
370 (declare (type alien-value alien)
372 (optimize (inhibit-warnings 3)))
373 (multiple-value-bind (target-type offset) (deref-guts alien indices)
374 (extract-alien-value (alien-value-sap alien)
378 (defun %set-deref (alien value &rest indices)
379 (declare (type alien-value alien)
381 (optimize (inhibit-warnings 3)))
382 (multiple-value-bind (target-type offset) (deref-guts alien indices)
383 (deposit-alien-value (alien-value-sap alien)
388 (defun %deref-addr (alien &rest indices)
389 (declare (type alien-value alien)
391 (optimize (inhibit-warnings 3)))
392 (multiple-value-bind (target-type offset) (deref-guts alien indices)
393 (%sap-alien (sap+ (alien-value-sap alien) (/ offset sb!vm:byte-bits))
394 (make-alien-pointer-type :to target-type))))
396 ;;;; accessing heap alien variables
398 (defun %heap-alien (info)
399 (declare (type heap-alien-info info)
400 (optimize (inhibit-warnings 3)))
401 (extract-alien-value (eval (heap-alien-info-sap-form info))
403 (heap-alien-info-type info)))
405 (defun %set-heap-alien (info value)
406 (declare (type heap-alien-info info)
407 (optimize (inhibit-warnings 3)))
408 (deposit-alien-value (eval (heap-alien-info-sap-form info))
410 (heap-alien-info-type info)
413 (defun %heap-alien-addr (info)
414 (declare (type heap-alien-info info)
415 (optimize (inhibit-warnings 3)))
416 (%sap-alien (eval (heap-alien-info-sap-form info))
417 (make-alien-pointer-type :to (heap-alien-info-type info))))
419 ;;;; accessing local aliens
421 (defun make-local-alien (info)
422 (let* ((alien (eval `(make-alien ,(local-alien-info-type info))))
423 (alien-sap (alien-sap alien)))
428 (extern-alien "free" (function (values) system-area-pointer))
432 (defun note-local-alien-type (info alien)
433 (declare (ignore info alien))
436 (defun local-alien (info alien)
437 (declare (ignore info))
440 (defun %set-local-alien (info alien value)
441 (declare (ignore info))
442 (setf (deref alien) value))
444 (define-setf-expander local-alien (&whole whole info alien)
445 (let ((value (gensym))
446 (info (if (and (consp info)
447 (eq (car info) 'quote))
449 (error "Something is wrong; local-alien-info not found: ~S"
454 (if sb!c:*converting-for-interpreter*
455 `(%set-local-alien ',info ,alien ,value)
456 `(if (%local-alien-forced-to-memory-p ',info)
457 (%set-local-alien ',info ,alien ,value)
459 (deport ,value ',(local-alien-info-type info)))))
462 (defun %local-alien-forced-to-memory-p (info)
463 (local-alien-info-force-to-memory-p info))
465 (defun %local-alien-addr (info alien)
466 (declare (type local-alien-info info))
467 (unless (local-alien-info-force-to-memory-p info)
468 (error "~S isn't forced to memory. Something went wrong." alien))
471 (defun dispose-local-alien (info alien)
472 (declare (ignore info))
473 (cancel-finalization alien)
478 (defmacro cast (alien type &environment env)
480 "Convert ALIEN to an Alien of the specified TYPE (not evaluated.) Both types
481 must be Alien array, pointer or function types."
482 `(%cast ,alien ',(parse-alien-type type env)))
484 (defun %cast (alien target-type)
485 (declare (type alien-value alien)
486 (type alien-type target-type)
487 (optimize-interface (safety 2))
488 (optimize (inhibit-warnings 3)))
489 (if (or (alien-pointer-type-p target-type)
490 (alien-array-type-p target-type)
491 (alien-function-type-p target-type))
492 (let ((alien-type (alien-value-type alien)))
493 (if (or (alien-pointer-type-p alien-type)
494 (alien-array-type-p alien-type)
495 (alien-function-type-p alien-type))
496 (naturalize (alien-value-sap alien) target-type)
497 (error "~S cannot be casted." alien)))
498 (error "cannot cast to alien type ~S" (unparse-alien-type target-type))))
500 ;;;; the ALIEN-SIZE macro
502 (defmacro alien-size (type &optional (units :bits) &environment env)
504 "Return the size of the alien type TYPE. UNITS specifies the units to
505 use and can be either :BITS, :BYTES, or :WORDS."
506 (let* ((alien-type (parse-alien-type type env))
507 (bits (alien-type-bits alien-type)))
509 (values (ceiling bits
512 (:bytes sb!vm:byte-bits)
513 (:words sb!vm:word-bits))))
514 (error "unknown size for alien type ~S"
515 (unparse-alien-type alien-type)))))
517 ;;;; NATURALIZE, DEPORT, EXTRACT-ALIEN-VALUE, DEPOSIT-ALIEN-VALUE
519 (defun naturalize (alien type)
520 (declare (type alien-type type))
521 (funcall (coerce (compute-naturalize-lambda type) 'function)
524 (defun deport (value type)
525 (declare (type alien-type type))
526 (funcall (coerce (compute-deport-lambda type) 'function)
529 (defun extract-alien-value (sap offset type)
530 (declare (type system-area-pointer sap)
531 (type unsigned-byte offset)
532 (type alien-type type))
533 (funcall (coerce (compute-extract-lambda type) 'function)
536 (defun deposit-alien-value (sap offset type value)
537 (declare (type system-area-pointer sap)
538 (type unsigned-byte offset)
539 (type alien-type type))
540 (funcall (coerce (compute-deposit-lambda type) 'function)
541 sap offset type value))
543 ;;;; ALIEN-FUNCALL, DEF-ALIEN-ROUTINE
545 (defun alien-funcall (alien &rest args)
547 "Call the foreign function ALIEN with the specified arguments. ALIEN's
548 type specifies the argument and result types."
549 (declare (type alien-value alien))
550 (let ((type (alien-value-type alien)))
553 (apply #'alien-funcall (deref alien) args))
555 (unless (= (length (alien-function-type-arg-types type))
557 (error "wrong number of arguments for ~S~%expected ~D, got ~D"
559 (length (alien-function-type-arg-types type))
561 (let ((stub (alien-function-type-stub type)))
565 (parms (loop repeat (length args) collect (gensym))))
567 `(lambda (,fun ,@parms)
568 (declare (type (alien ,type) ,fun))
569 (alien-funcall ,fun ,@parms)))))
570 (setf (alien-function-type-stub type) stub))
571 (apply stub alien args)))
573 (error "~S is not an alien function." alien)))))
575 (defmacro def-alien-routine (name result-type &rest args &environment env)
577 "Def-C-Routine Name Result-Type
578 {(Arg-Name Arg-Type [Style])}*
580 Define a foreign interface function for the routine with the specified Name,
581 which may be either a string, symbol or list of the form (string symbol).
582 Return-Type is the Alien type for the function return value. VOID may be
583 used to specify a function with no result.
585 The remaining forms specifiy individual arguments that are passed to the
586 routine. Arg-Name is a symbol that names the argument, primarily for
587 documentation. Arg-Type is the C-Type of the argument. Style specifies the
588 say that the argument is passed.
591 An :In argument is simply passed by value. The value to be passed is
592 obtained from argument(s) to the interface function. No values are
593 returned for :In arguments. This is the default mode.
596 The specified argument type must be a pointer to a fixed sized object.
597 A pointer to a preallocated object is passed to the routine, and the
598 the object is accessed on return, with the value being returned from
599 the interface function. :OUT and :IN-OUT cannot be used with pointers
600 to arrays, records or functions.
603 Similar to :IN, except that the argument values are stored in on
604 the stack, and a pointer to the object is passed instead of
605 the values themselves.
608 A combination of :OUT and :COPY. A pointer to the argument is passed,
609 with the object being initialized from the supplied argument and
610 the return value being determined by accessing the object on return."
611 (multiple-value-bind (lisp-name alien-name)
612 (pick-lisp-and-alien-names name)
613 (collect ((docs) (lisp-args) (arg-types) (alien-vars)
614 (alien-args) (results))
618 (destructuring-bind (name type &optional (style :in)) arg
619 (unless (member style '(:in :copy :out :in-out))
620 (error "bogus argument style ~S in ~S" style arg))
621 (unless (eq style :out)
623 (when (and (member style '(:out :in-out))
624 (typep (parse-alien-type type env)
625 'alien-pointer-type))
626 (error "can't use :OUT or :IN-OUT on pointer-like type:~% ~S"
628 (cond ((eq style :in)
632 (arg-types `(* ,type))
634 (alien-vars `(,name ,type))
635 (alien-vars `(,name ,type ,name)))
636 (alien-args `(addr ,name))))
637 (when (or (eq style :out) (eq style :in-out))
639 `(defun ,lisp-name ,(lisp-args)
642 ((,lisp-name (function ,result-type ,@(arg-types))
645 ,(if (alien-values-type-p result-type)
647 repeat (length (alien-values-type-values
650 `(multiple-value-bind ,temps
651 (alien-funcall ,lisp-name ,@(alien-args))
652 (values ,@temps ,@(results))))
653 `(values (alien-funcall ,lisp-name ,@(alien-args))
656 (defun alien-typep (object type)
658 "Return T iff OBJECT is an alien of type TYPE."
659 (let ((lisp-rep-type (compute-lisp-rep-type type)))
661 (typep object lisp-rep-type)
662 (and (alien-value-p object)
663 (alien-subtype-p (alien-value-type object) type)))))