src/code/host-alieneval.lisp

   1 ;;;; the part of the Alien implementation which is needed at
   2 ;;;; cross-compilation time
   3
   4 ;;;; This software is part of the SBCL system. See the README file for
   5 ;;;; more information.
   6 ;;;;
   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.
  12
  13 (in-package "SB!ALIEN")
  14
  15 (/show0 "host-alieneval.lisp 15")
  16 \f
  17 ;;;; utility functions
  18
  19 (defun align-offset (offset alignment)
  20   (let ((extra (rem offset alignment)))
  21     (if (zerop extra) offset (+ offset (- alignment extra)))))
  22
  23 (defun guess-alignment (bits)
  24   (cond ((null bits) nil)
  25         #!-(or (and x86 (not win32)) (and ppc darwin)) ((> bits 32) 64)
  26         ((> bits 16) 32)
  27         ((> bits 8) 16)
  28         ((> bits 1) 8)
  29         (t 1)))
  30 \f
  31 ;;;; ALIEN-TYPE-INFO stuff
  32
  33 (eval-when (#-sb-xc :compile-toplevel :execute :load-toplevel)
  34
  35 (defstruct (alien-type-class (:copier nil))
  36   (name nil :type symbol)
  37   (defstruct-name nil :type symbol)
  38   (include nil :type (or null alien-type-class))
  39   (unparse nil :type (or null function))
  40   (type= nil :type (or null function))
  41   (lisp-rep nil :type (or null function))
  42   (alien-rep nil :type (or null function))
  43   (extract-gen nil :type (or null function))
  44   (deposit-gen nil :type (or null function))
  45   (naturalize-gen nil :type (or null function))
  46   (deport-gen nil :type (or null function))
  47   (deport-alloc-gen nil :type (or null function))
  48   (deport-pin-p nil :type (or null function))
  49   ;; Cast?
  50   (arg-tn nil :type (or null function))
  51   (result-tn nil :type (or null function))
  52   (subtypep nil :type (or null function)))
  53 (def!method print-object ((type-class alien-type-class) stream)
  54   (print-unreadable-object (type-class stream :type t)
  55     (prin1 (alien-type-class-name type-class) stream)))
  56
  57 (defun alien-type-class-or-lose (name)
  58   (or (gethash name *alien-type-classes*)
  59       (error "no alien type class ~S" name)))
  60
  61 (defun create-alien-type-class-if-necessary (name defstruct-name include)
  62   (let ((old (gethash name *alien-type-classes*))
  63         (include (and include (alien-type-class-or-lose include))))
  64     (if old
  65         (setf (alien-type-class-include old) include)
  66         (setf (gethash name *alien-type-classes*)
  67               (make-alien-type-class :name name
  68                                      :defstruct-name defstruct-name
  69                                      :include include)))))
  70
  71 (defparameter *method-slot-alist*
  72   '((:unparse . alien-type-class-unparse)
  73     (:type= . alien-type-class-type=)
  74     (:subtypep . alien-type-class-subtypep)
  75     (:lisp-rep . alien-type-class-lisp-rep)
  76     (:alien-rep . alien-type-class-alien-rep)
  77     (:extract-gen . alien-type-class-extract-gen)
  78     (:deposit-gen . alien-type-class-deposit-gen)
  79     (:naturalize-gen . alien-type-class-naturalize-gen)
  80     (:deport-gen . alien-type-class-deport-gen)
  81     (:deport-alloc-gen . alien-type-class-deport-alloc-gen)
  82     (:deport-pin-p . alien-type-class-deport-pin-p)
  83     ;; cast?
  84     (:arg-tn . alien-type-class-arg-tn)
  85     (:result-tn . alien-type-class-result-tn)))
  86
  87 (defun method-slot (method)
  88   (cdr (or (assoc method *method-slot-alist*)
  89            (error "no method ~S" method))))
  90
  91 ) ; EVAL-WHEN
  92
  93 ;;; We define a keyword "BOA" constructor so that we can reference the
  94 ;;; slot names in init forms.
  95 (def!macro define-alien-type-class ((name &key include include-args)
  96                                     &rest slots)
  97   (let ((defstruct-name (symbolicate "ALIEN-" name "-TYPE")))
  98     (multiple-value-bind (include include-defstruct overrides)
  99         (etypecase include
 100           (null
 101            (values nil 'alien-type nil))
 102           (symbol
 103            (values
 104             include
 105             (alien-type-class-defstruct-name
 106              (alien-type-class-or-lose include))
 107             nil))
 108           (list
 109            (values
 110             (car include)
 111             (alien-type-class-defstruct-name
 112              (alien-type-class-or-lose (car include)))
 113             (cdr include))))
 114       `(progn
 115          (eval-when (:compile-toplevel :load-toplevel :execute)
 116            (create-alien-type-class-if-necessary ',name ',defstruct-name
 117                                                  ',(or include 'root)))
 118          (def!struct (,defstruct-name
 119                         (:include ,include-defstruct
 120                                   (class ',name)
 121                                   ,@overrides)
 122                         (:constructor
 123                          ,(symbolicate "MAKE-" defstruct-name)
 124                          (&key class bits alignment
 125                                ,@(mapcar (lambda (x)
 126                                            (if (atom x) x (car x)))
 127                                          slots)
 128                                ,@include-args
 129                                ;; KLUDGE
 130                                &aux (alignment (or alignment (guess-alignment bits))))))
 131            ,@slots)))))
 132
 133 (def!macro define-alien-type-method ((class method) lambda-list &rest body)
 134   (let ((defun-name (symbolicate class "-" method "-METHOD")))
 135     `(progn
 136        (defun ,defun-name ,lambda-list
 137          ,@body)
 138        (setf (,(method-slot method) (alien-type-class-or-lose ',class))
 139              #',defun-name))))
 140
 141 (def!macro invoke-alien-type-method (method type &rest args)
 142   (let ((slot (method-slot method)))
 143     (once-only ((type type))
 144       `(funcall (do ((class (alien-type-class-or-lose (alien-type-class ,type))
 145                             (alien-type-class-include class)))
 146                     ((null class)
 147                      (error "method ~S not defined for ~S"
 148                             ',method (alien-type-class ,type)))
 149                   (let ((fn (,slot class)))
 150                     (when fn
 151                       (return fn))))
 152                 ,type ,@args))))
 153 \f
 154 ;;;; type parsing and unparsing
 155
 156 ;;; CMU CL used COMPILER-LET to bind *AUXILIARY-TYPE-DEFINITIONS*, and
 157 ;;; COMPILER-LET is no longer supported by ANSI or SBCL. Instead, we
 158 ;;; follow the suggestion in CLTL2 of using SYMBOL-MACROLET to achieve
 159 ;;; a similar effect.
 160 (eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
 161   (defun auxiliary-type-definitions (env)
 162     (multiple-value-bind (result expanded-p)
 163         (sb!xc:macroexpand '&auxiliary-type-definitions& env)
 164       (if expanded-p
 165           result
 166           ;; This is like having the global symbol-macro definition be
 167           ;; NIL, but global symbol-macros make me vaguely queasy, so
 168           ;; I do it this way instead.
 169           nil))))
 170
 171 ;;; Process stuff in a new scope.
 172 (def!macro with-auxiliary-alien-types (env &body body)
 173   ``(symbol-macrolet ((&auxiliary-type-definitions&
 174                        ,(append *new-auxiliary-types*
 175                                 (auxiliary-type-definitions ,env))))
 176       ,(let ((*new-auxiliary-types* nil))
 177          ,@body)))
 178
 179 ;;; Parse TYPE as an alien type specifier and return the resultant
 180 ;;; ALIEN-TYPE structure.
 181 (defun parse-alien-type (type env)
 182   (declare (type (or sb!kernel:lexenv null) env))
 183   (if (consp type)
 184       (let ((translator (info :alien-type :translator (car type))))
 185         (unless translator
 186           (error "unknown alien type: ~S" type))
 187         (funcall translator type env))
 188       (ecase (info :alien-type :kind type)
 189         (:primitive
 190          (let ((translator (info :alien-type :translator type)))
 191            (unless translator
 192              (error "no translator for primitive alien type ~S" type))
 193            (funcall translator (list type) env)))
 194         (:defined
 195          (or (info :alien-type :definition type)
 196              (error "no definition for alien type ~S" type)))
 197         (:unknown
 198          (error "unknown alien type: ~S" type)))))
 199
 200 (defun auxiliary-alien-type (kind name env)
 201   (declare (type (or sb!kernel:lexenv null) env))
 202   (flet ((aux-defn-matches (x)
 203            (and (eq (first x) kind) (eq (second x) name))))
 204     (let ((in-auxiliaries
 205            (or (find-if #'aux-defn-matches *new-auxiliary-types*)
 206                (find-if #'aux-defn-matches (auxiliary-type-definitions env)))))
 207       (if in-auxiliaries
 208           (values (third in-auxiliaries) t)
 209           (ecase kind
 210             (:struct
 211              (info :alien-type :struct name))
 212             (:union
 213              (info :alien-type :union name))
 214             (:enum
 215              (info :alien-type :enum name)))))))
 216
 217 (defun (setf auxiliary-alien-type) (new-value kind name env)
 218   (declare (type (or sb!kernel:lexenv null) env))
 219   (flet ((aux-defn-matches (x)
 220            (and (eq (first x) kind) (eq (second x) name))))
 221     (when (find-if #'aux-defn-matches *new-auxiliary-types*)
 222       (error "attempt to multiply define ~A ~S" kind name))
 223     (when (find-if #'aux-defn-matches (auxiliary-type-definitions env))
 224       (error "attempt to shadow definition of ~A ~S" kind name)))
 225   (push (list kind name new-value) *new-auxiliary-types*)
 226   new-value)
 227
 228 (defun verify-local-auxiliaries-okay ()
 229   (dolist (info *new-auxiliary-types*)
 230     (destructuring-bind (kind name defn) info
 231       (declare (ignore defn))
 232       (when (ecase kind
 233               (:struct
 234                (info :alien-type :struct name))
 235               (:union
 236                (info :alien-type :union name))
 237               (:enum
 238                (info :alien-type :enum name)))
 239         (error "attempt to shadow definition of ~A ~S" kind name)))))
 240
 241 (defun unparse-alien-type (type)
 242   #!+sb-doc
 243   "Convert the alien-type structure TYPE back into a list specification of
 244    the type."
 245   (declare (type alien-type type))
 246   (let ((*record-types-already-unparsed* nil))
 247     (%unparse-alien-type type)))
 248
 249 ;;; Does all the work of UNPARSE-ALIEN-TYPE. It's separate because we
 250 ;;; need to recurse inside the binding of
 251 ;;; *RECORD-TYPES-ALREADY-UNPARSED*.
 252 (defun %unparse-alien-type (type)
 253   (invoke-alien-type-method :unparse type))
 254 \f
 255 ;;;; alien type defining stuff
 256
 257 (def!macro define-alien-type-translator (name lambda-list &body body)
 258   (with-unique-names (whole env)
 259     (let ((defun-name (symbolicate "ALIEN-" name "-TYPE-TRANSLATOR")))
 260       (multiple-value-bind (body decls docs)
 261           (sb!kernel:parse-defmacro lambda-list whole body name
 262                                     'define-alien-type-translator
 263                                     :environment env)
 264         `(eval-when (:compile-toplevel :load-toplevel :execute)
 265            (defun ,defun-name (,whole ,env)
 266              (declare (ignorable ,env))
 267              ,@decls
 268              (block ,name
 269                ,body))
 270            (%define-alien-type-translator ',name #',defun-name ,docs))))))
 271
 272 (eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
 273   (defun %define-alien-type-translator (name translator docs)
 274     (declare (ignore docs))
 275     (setf (info :alien-type :kind name) :primitive)
 276     (setf (info :alien-type :translator name) translator)
 277     (clear-info :alien-type :definition name)
 278     #+nil
 279     (setf (fdocumentation name 'alien-type) docs)
 280     name))
 281
 282 (def!macro define-alien-type (name type &environment env)
 283   #!+sb-doc
 284   "Define the alien type NAME to be equivalent to TYPE. Name may be NIL for
 285    STRUCT and UNION types, in which case the name is taken from the type
 286    specifier."
 287   (with-auxiliary-alien-types env
 288     (let ((alien-type (parse-alien-type type env)))
 289       `(eval-when (:compile-toplevel :load-toplevel :execute)
 290          ,@(when *new-auxiliary-types*
 291              `((%def-auxiliary-alien-types ',*new-auxiliary-types*)))
 292          ,@(when name
 293              `((%define-alien-type ',name ',alien-type)))))))
 294
 295 (eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
 296   (defun %def-auxiliary-alien-types (types)
 297     (dolist (info types)
 298       ;; Clear up the type we're about to define from the toplevel
 299       ;; *new-auxiliary-types* (local scopes take care of themselves).
 300       ;; Unless this is done we never actually get back the full type
 301       ;; from INFO, since the *new-auxiliary-types* have precendence.
 302       (setf *new-auxiliary-types*
 303             (remove info *new-auxiliary-types*
 304                     :test (lambda (a b)
 305                             (and (eq (first a) (first b))
 306                                  (eq (second a) (second b))))))
 307       (destructuring-bind (kind name defn) info
 308         (macrolet ((frob (kind)
 309                          `(let ((old (info :alien-type ,kind name)))
 310                             (unless (or (null old) (alien-type-= old defn))
 311                               (warn
 312                                "redefining ~A ~S to be:~%  ~S,~%was:~%  ~S"
 313                                kind name defn old))
 314                             (setf (info :alien-type ,kind name) defn))))
 315           (ecase kind
 316             (:struct (frob :struct))
 317             (:union (frob :union))
 318             (:enum (frob :enum)))))))
 319   (defun %define-alien-type (name new)
 320     (ecase (info :alien-type :kind name)
 321       (:primitive
 322        (error "~S is a built-in alien type." name))
 323       (:defined
 324        (let ((old (info :alien-type :definition name)))
 325          (unless (or (null old) (alien-type-= new old))
 326            (warn "redefining ~S to be:~%  ~S,~%was~%  ~S"
 327                  name
 328                  (unparse-alien-type new)
 329                  (unparse-alien-type old)))))
 330       (:unknown))
 331     (setf (info :alien-type :definition name) new)
 332     (setf (info :alien-type :kind name) :defined)
 333     name))
 334 \f
 335 ;;;; the root alien type
 336
 337 (eval-when (:compile-toplevel :load-toplevel :execute)
 338   (create-alien-type-class-if-necessary 'root 'alien-type nil))
 339
 340 (def!struct (alien-type
 341              (:make-load-form-fun sb!kernel:just-dump-it-normally)
 342              (:constructor make-alien-type (&key class bits alignment
 343                                             &aux (alignment (or alignment (guess-alignment bits))))))
 344   (class 'root :type symbol)
 345   (bits nil :type (or null unsigned-byte))
 346   (alignment nil :type (or null unsigned-byte)))
 347 (def!method print-object ((type alien-type) stream)
 348   (print-unreadable-object (type stream :type t)
 349     (prin1 (unparse-alien-type type) stream)))
 350 \f
 351 ;;;; the SAP type
 352
 353 (define-alien-type-class (system-area-pointer))
 354
 355 (define-alien-type-translator system-area-pointer ()
 356   (make-alien-system-area-pointer-type
 357    :bits #!-alpha sb!vm:n-word-bits #!+alpha 64))
 358
 359 (define-alien-type-method (system-area-pointer :unparse) (type)
 360   (declare (ignore type))
 361   'system-area-pointer)
 362
 363 (define-alien-type-method (system-area-pointer :lisp-rep) (type)
 364   (declare (ignore type))
 365   'system-area-pointer)
 366
 367 (define-alien-type-method (system-area-pointer :alien-rep) (type context)
 368   (declare (ignore type context))
 369   'system-area-pointer)
 370
 371 (define-alien-type-method (system-area-pointer :naturalize-gen) (type alien)
 372   (declare (ignore type))
 373   alien)
 374
 375 (define-alien-type-method (system-area-pointer :deport-gen) (type object)
 376   (declare (ignore type))
 377   (/noshow "doing alien type method SYSTEM-AREA-POINTER :DEPORT-GEN" object)
 378   object)
 379
 380 (define-alien-type-method (system-area-pointer :extract-gen) (type sap offset)
 381   (declare (ignore type))
 382   `(sap-ref-sap ,sap (/ ,offset sb!vm:n-byte-bits)))
 383 \f
 384 ;;;; the ALIEN-VALUE type
 385
 386 (define-alien-type-class (alien-value :include system-area-pointer))
 387
 388 (define-alien-type-method (alien-value :lisp-rep) (type)
 389   (declare (ignore type))
 390   nil)
 391
 392 (define-alien-type-method (alien-value :naturalize-gen) (type alien)
 393   `(%sap-alien ,alien ',type))
 394
 395 (define-alien-type-method (alien-value :deport-gen) (type value)
 396   (declare (ignore type))
 397   (/noshow "doing alien type method ALIEN-VALUE :DEPORT-GEN" value)
 398   `(alien-sap ,value))
 399 \f
 400 ;;; HEAP-ALIEN-INFO -- defstruct.
 401 ;;;
 402 ;;; Information describing a heap-allocated alien.
 403 (def!struct (heap-alien-info
 404              (:make-load-form-fun sb!kernel:just-dump-it-normally))
 405   ;; The type of this alien.
 406   (type (missing-arg) :type alien-type)
 407   ;; The form to evaluate to produce the SAP pointing to where in the heap
 408   ;; it is.
 409   (sap-form (missing-arg)))
 410 (def!method print-object ((info heap-alien-info) stream)
 411   (print-unreadable-object (info stream :type t)
 412     (funcall (formatter "~S ~S")
 413              stream
 414              (heap-alien-info-sap-form info)
 415              (unparse-alien-type (heap-alien-info-type info)))))
 416 \f
 417 ;;;; Interfaces to the different methods
 418
 419 (defun alien-type-= (type1 type2)
 420   #!+sb-doc
 421   "Return T iff TYPE1 and TYPE2 describe equivalent alien types."
 422   (or (eq type1 type2)
 423       (and (eq (alien-type-class type1)
 424                (alien-type-class type2))
 425            (invoke-alien-type-method :type= type1 type2))))
 426
 427 (defun alien-subtype-p (type1 type2)
 428   #!+sb-doc
 429   "Return T iff the alien type TYPE1 is a subtype of TYPE2. Currently, the
 430    only supported subtype relationships are is that any pointer type is a
 431    subtype of (* t), and any array type first dimension will match
 432    (array <eltype> nil ...). Otherwise, the two types have to be
 433    ALIEN-TYPE-=."
 434   (or (eq type1 type2)
 435       (invoke-alien-type-method :subtypep type1 type2)))
 436
 437 (defun compute-naturalize-lambda (type)
 438   `(lambda (alien ignore)
 439      (declare (ignore ignore))
 440      ,(invoke-alien-type-method :naturalize-gen type 'alien)))
 441
 442 (defun compute-deport-lambda (type)
 443   (declare (type alien-type type))
 444   (/noshow "entering COMPUTE-DEPORT-LAMBDA" type)
 445   (multiple-value-bind (form value-type)
 446       (invoke-alien-type-method :deport-gen type 'value)
 447     `(lambda (value ignore)
 448        (declare (type ,(or value-type
 449                            (compute-lisp-rep-type type)
 450                            `(alien ,type))
 451                       value)
 452                 (ignore ignore))
 453        ,form)))
 454
 455 (defun compute-deport-alloc-lambda (type)
 456   `(lambda (value ignore)
 457      (declare (ignore ignore))
 458      ,(invoke-alien-type-method :deport-alloc-gen type 'value)))
 459
 460 (defun compute-extract-lambda (type)
 461   `(lambda (sap offset ignore)
 462      (declare (type system-area-pointer sap)
 463               (type unsigned-byte offset)
 464               (ignore ignore))
 465      (naturalize ,(invoke-alien-type-method :extract-gen type 'sap 'offset)
 466                  ',type)))
 467
 468 (def!macro maybe-with-pinned-objects (variables types &body body)
 469   (declare (ignorable variables types))
 470   (let ((pin-variables
 471          ;; Only pin things on x86/x86-64, since on non-conservative
 472          ;; gcs it'd imply disabling the GC. Which is something we
 473          ;; don't want to do every time we're calling to C.
 474          #!+(or x86 x86-64)
 475          (loop for variable in variables
 476             for type in types
 477             when (invoke-alien-type-method :deport-pin-p type)
 478             collect variable)))
 479     (if pin-variables
 480         `(with-pinned-objects ,pin-variables
 481            ,@body)
 482         `(progn
 483            ,@body))))
 484
 485 (defun compute-deposit-lambda (type)
 486   (declare (type alien-type type))
 487   `(lambda (sap offset ignore value)
 488      (declare (type system-area-pointer sap)
 489               (type unsigned-byte offset)
 490               (ignore ignore))
 491      (let ((alloc-tmp (deport-alloc value ',type)))
 492        (maybe-with-pinned-objects (alloc-tmp) (,type)
 493          (let ((value (deport alloc-tmp  ',type)))
 494            ,(invoke-alien-type-method :deposit-gen type 'sap 'offset 'value)
 495            ;; Note: the reason we don't just return the pre-deported value
 496            ;; is because that would inhibit any (deport (naturalize ...))
 497            ;; optimizations that might have otherwise happen. Re-naturalizing
 498            ;; the value might cause extra consing, but is flushable, so probably
 499            ;; results in better code.
 500            (naturalize value ',type))))))
 501
 502 (defun compute-lisp-rep-type (type)
 503   (invoke-alien-type-method :lisp-rep type))
 504
 505 ;;; CONTEXT is either :NORMAL (the default) or :RESULT (alien function
 506 ;;; return values).  See the :ALIEN-REP method for INTEGER for
 507 ;;; details.
 508 (defun compute-alien-rep-type (type &optional (context :normal))
 509   (invoke-alien-type-method :alien-rep type context))
 510 \f
 511 ;;;; default methods
 512
 513 (define-alien-type-method (root :unparse) (type)
 514   `(<unknown-alien-type> ,(type-of type)))
 515
 516 (define-alien-type-method (root :type=) (type1 type2)
 517   (declare (ignore type1 type2))
 518   t)
 519
 520 (define-alien-type-method (root :subtypep) (type1 type2)
 521   (alien-type-= type1 type2))
 522
 523 (define-alien-type-method (root :lisp-rep) (type)
 524   (declare (ignore type))
 525   nil)
 526
 527 (define-alien-type-method (root :alien-rep) (type context)
 528   (declare (ignore type context))
 529   '*)
 530
 531 (define-alien-type-method (root :naturalize-gen) (type alien)
 532   (declare (ignore alien))
 533   (error "cannot represent ~S typed aliens" type))
 534
 535 (define-alien-type-method (root :deport-gen) (type object)
 536   (declare (ignore object))
 537   (error "cannot represent ~S typed aliens" type))
 538
 539 (define-alien-type-method (root :deport-alloc-gen) (type object)
 540   (declare (ignore type))
 541   object)
 542
 543 (define-alien-type-method (root :deport-pin-p) (type)
 544   (declare (ignore type))
 545   ;; Override this method to return T for classes which take a SAP to a
 546   ;; GCable lisp object when deporting.
 547   nil)
 548
 549 (define-alien-type-method (root :extract-gen) (type sap offset)
 550   (declare (ignore sap offset))
 551   (error "cannot represent ~S typed aliens" type))
 552
 553 (define-alien-type-method (root :deposit-gen) (type sap offset value)
 554   `(setf ,(invoke-alien-type-method :extract-gen type sap offset) ,value))
 555
 556 (define-alien-type-method (root :arg-tn) (type state)
 557   (declare (ignore state))
 558   (error "Aliens of type ~S cannot be passed as arguments to CALL-OUT."
 559          (unparse-alien-type type)))
 560
 561 (define-alien-type-method (root :result-tn) (type state)
 562   (declare (ignore state))
 563   (error "Aliens of type ~S cannot be returned from CALL-OUT."
 564          (unparse-alien-type type)))
 565 \f
 566 ;;;; the INTEGER type
 567
 568 (define-alien-type-class (integer)
 569   (signed t :type (member t nil)))
 570
 571 (define-alien-type-translator signed (&optional (bits sb!vm:n-word-bits))
 572   (make-alien-integer-type :bits bits))
 573
 574 (define-alien-type-translator integer (&optional (bits sb!vm:n-word-bits))
 575   (make-alien-integer-type :bits bits))
 576
 577 (define-alien-type-translator unsigned (&optional (bits sb!vm:n-word-bits))
 578   (make-alien-integer-type :bits bits :signed nil))
 579
 580 (define-alien-type-method (integer :unparse) (type)
 581   (list (if (alien-integer-type-signed type) 'signed 'unsigned)
 582         (alien-integer-type-bits type)))
 583
 584 (define-alien-type-method (integer :type=) (type1 type2)
 585   (and (eq (alien-integer-type-signed type1)
 586            (alien-integer-type-signed type2))
 587        (= (alien-integer-type-bits type1)
 588           (alien-integer-type-bits type2))))
 589
 590 (define-alien-type-method (integer :lisp-rep) (type)
 591   (list (if (alien-integer-type-signed type) 'signed-byte 'unsigned-byte)
 592         (alien-integer-type-bits type)))
 593
 594 (define-alien-type-method (integer :alien-rep) (type context)
 595   ;; When returning integer values that are narrower than a machine
 596   ;; register from a function, some platforms leave the higher bits of
 597   ;; the register uninitialized.  On those platforms, we use an
 598   ;; alien-rep of the full register width when checking for purposes
 599   ;; of return values and override the naturalize method to perform
 600   ;; the sign extension (in compiler/target/c-call.lisp).
 601   (ecase context
 602     ((:normal #!-(or x86 x86-64) :result)
 603      (list (if (alien-integer-type-signed type) 'signed-byte 'unsigned-byte)
 604            (alien-integer-type-bits type)))
 605     #!+(or x86 x86-64)
 606     (:result
 607      (list (if (alien-integer-type-signed type) 'signed-byte 'unsigned-byte)
 608            sb!vm:n-word-bits))))
 609
 610 ;;; As per the comment in the :ALIEN-REP method above, this is defined
 611 ;;; elsewhere for x86oids.
 612 #!-(or x86 x86-64)
 613 (define-alien-type-method (integer :naturalize-gen) (type alien)
 614   (declare (ignore type))
 615   alien)
 616
 617 (define-alien-type-method (integer :deport-gen) (type value)
 618   (declare (ignore type))
 619   value)
 620
 621 (define-alien-type-method (integer :extract-gen) (type sap offset)
 622   (declare (type alien-integer-type type))
 623   (let ((ref-fun
 624          (if (alien-integer-type-signed type)
 625           (case (alien-integer-type-bits type)
 626             (8 'signed-sap-ref-8)
 627             (16 'signed-sap-ref-16)
 628             (32 'signed-sap-ref-32)
 629             (64 'signed-sap-ref-64))
 630           (case (alien-integer-type-bits type)
 631             (8 'sap-ref-8)
 632             (16 'sap-ref-16)
 633             (32 'sap-ref-32)
 634             (64 'sap-ref-64)))))
 635     (if ref-fun
 636         `(,ref-fun ,sap (/ ,offset sb!vm:n-byte-bits))
 637         (error "cannot extract ~W-bit integers"
 638                (alien-integer-type-bits type)))))
 639 \f
 640 ;;;; the BOOLEAN type
 641
 642 (define-alien-type-class (boolean :include integer :include-args (signed)))
 643
 644 ;;; FIXME: Check to make sure that we aren't attaching user-readable
 645 ;;; stuff to CL:BOOLEAN in any way which impairs ANSI compliance.
 646 (define-alien-type-translator boolean (&optional (bits sb!vm:n-word-bits))
 647   (make-alien-boolean-type :bits bits :signed nil))
 648
 649 (define-alien-type-method (boolean :unparse) (type)
 650   `(boolean ,(alien-boolean-type-bits type)))
 651
 652 (define-alien-type-method (boolean :lisp-rep) (type)
 653   (declare (ignore type))
 654   `(member t nil))
 655
 656 (define-alien-type-method (boolean :naturalize-gen) (type alien)
 657   (declare (ignore type))
 658   `(not (zerop ,alien)))
 659
 660 (define-alien-type-method (boolean :deport-gen) (type value)
 661   (declare (ignore type))
 662   `(if ,value 1 0))
 663 \f
 664 ;;;; the ENUM type
 665
 666 (define-alien-type-class (enum :include (integer (bits 32))
 667                                :include-args (signed))
 668   name          ; name of this enum (if any)
 669   from          ; alist from symbols to integers
 670   to            ; alist or vector from integers to symbols
 671   kind          ; kind of from mapping, :VECTOR or :ALIST
 672   offset)       ; offset to add to value for :VECTOR from mapping
 673
 674 (define-alien-type-translator enum (&whole
 675                                  type name
 676                                  &rest mappings
 677                                  &environment env)
 678   (cond (mappings
 679          (let ((result (parse-enum name mappings)))
 680            (when name
 681              (multiple-value-bind (old old-p)
 682                  (auxiliary-alien-type :enum name env)
 683                (when old-p
 684                  (unless (alien-type-= result old)
 685                    (cerror "Continue, clobbering the old definition"
 686                            "Incompatible alien enum type definition: ~S" name)
 687                    (setf (alien-type-from old) (alien-type-from result)
 688                          (alien-type-to old) (alien-type-to result)
 689                          (alien-type-kind old) (alien-type-kind result)
 690                          (alien-type-offset old) (alien-type-offset result)
 691                          (alien-type-signed old) (alien-type-signed result)))
 692                  (setf result old))
 693                (unless old-p
 694                  (setf (auxiliary-alien-type :enum name env) result))))
 695            result))
 696         (name
 697          (multiple-value-bind (result found)
 698              (auxiliary-alien-type :enum name env)
 699            (unless found
 700              (error "unknown enum type: ~S" name))
 701            result))
 702         (t
 703          (error "empty enum type: ~S" type))))
 704
 705 (defun parse-enum (name elements)
 706   (when (null elements)
 707     (error "An enumeration must contain at least one element."))
 708   (let ((min nil)
 709         (max nil)
 710         (from-alist ())
 711         (prev -1))
 712     (declare (list from-alist))
 713     (dolist (el elements)
 714       (multiple-value-bind (sym val)
 715           (if (listp el)
 716               (values (first el) (second el))
 717               (values el (1+ prev)))
 718         (setf prev val)
 719         (unless (symbolp sym)
 720           (error "The enumeration element ~S is not a symbol." sym))
 721         (unless (integerp val)
 722           (error "The element value ~S is not an integer." val))
 723         (unless (and max (> max val)) (setq max val))
 724         (unless (and min (< min val)) (setq min val))
 725         (when (rassoc val from-alist)
 726           (style-warn "The element value ~S is used more than once." val))
 727         (when (assoc sym from-alist :test #'eq)
 728           (error "The enumeration element ~S is used more than once." sym))
 729         (push (cons sym val) from-alist)))
 730     (let* ((signed (minusp min))
 731            (min-bits (if signed
 732                          (1+ (max (integer-length min)
 733                                   (integer-length max)))
 734                          (integer-length max))))
 735       (when (> min-bits 32)
 736         (error "can't represent enums needing more than 32 bits"))
 737       (setf from-alist (sort from-alist #'< :key #'cdr))
 738       (cond
 739        ;; If range is at least 20% dense, use vector mapping. Crossover
 740        ;; point solely on basis of space would be 25%. Vector mapping
 741        ;; is always faster, so give the benefit of the doubt.
 742        ((< 0.2 (/ (float (length from-alist)) (float (1+ (- max min)))))
 743         ;; If offset is small and ignorable, ignore it to save time.
 744         (when (< 0 min 10) (setq min 0))
 745         (let ((to (make-array (1+ (- max min)))))
 746           (dolist (el from-alist)
 747             (setf (svref to (- (cdr el) min)) (car el)))
 748           (make-alien-enum-type :name name :signed signed
 749                                 :from from-alist :to to :kind
 750                                 :vector :offset (- min))))
 751        (t
 752         (make-alien-enum-type :name name :signed signed
 753                               :from from-alist
 754                               :to (mapcar (lambda (x) (cons (cdr x) (car x)))
 755                                           from-alist)
 756                               :kind :alist))))))
 757
 758 (define-alien-type-method (enum :unparse) (type)
 759   `(enum ,(alien-enum-type-name type)
 760          ,@(let ((prev -1))
 761              (mapcar (lambda (mapping)
 762                        (let ((sym (car mapping))
 763                              (value (cdr mapping)))
 764                          (prog1
 765                              (if (= (1+ prev) value)
 766                                  sym
 767                                  `(,sym ,value))
 768                            (setf prev value))))
 769                      (alien-enum-type-from type)))))
 770
 771 (define-alien-type-method (enum :type=) (type1 type2)
 772   (and (eq (alien-enum-type-name type1)
 773            (alien-enum-type-name type2))
 774        (equal (alien-enum-type-from type1)
 775               (alien-enum-type-from type2))))
 776
 777 (define-alien-type-method (enum :lisp-rep) (type)
 778   `(member ,@(mapcar #'car (alien-enum-type-from type))))
 779
 780 (define-alien-type-method (enum :naturalize-gen) (type alien)
 781   (ecase (alien-enum-type-kind type)
 782     (:vector
 783      `(svref ',(alien-enum-type-to type)
 784              (+ ,alien ,(alien-enum-type-offset type))))
 785     (:alist
 786      `(ecase ,alien
 787         ,@(mapcar (lambda (mapping)
 788                     `(,(car mapping) ',(cdr mapping)))
 789                   (alien-enum-type-to type))))))
 790
 791 (define-alien-type-method (enum :deport-gen) (type value)
 792   `(ecase ,value
 793      ,@(mapcar (lambda (mapping)
 794                  `(,(car mapping) ,(cdr mapping)))
 795                (alien-enum-type-from type))))
 796 \f
 797 ;;;; the FLOAT types
 798
 799 (define-alien-type-class (float)
 800   (type (missing-arg) :type symbol))
 801
 802 (define-alien-type-method (float :unparse) (type)
 803   (alien-float-type-type type))
 804
 805 (define-alien-type-method (float :lisp-rep) (type)
 806   (alien-float-type-type type))
 807
 808 (define-alien-type-method (float :alien-rep) (type context)
 809   (declare (ignore context))
 810   (alien-float-type-type type))
 811
 812 (define-alien-type-method (float :naturalize-gen) (type alien)
 813   (declare (ignore type))
 814   alien)
 815
 816 (define-alien-type-method (float :deport-gen) (type value)
 817   (declare (ignore type))
 818   value)
 819
 820 (define-alien-type-class (single-float :include (float (bits 32))
 821                                        :include-args (type)))
 822
 823 (define-alien-type-translator single-float ()
 824   (make-alien-single-float-type :type 'single-float))
 825
 826 (define-alien-type-method (single-float :extract-gen) (type sap offset)
 827   (declare (ignore type))
 828   `(sap-ref-single ,sap (/ ,offset sb!vm:n-byte-bits)))
 829
 830 (define-alien-type-class (double-float :include (float (bits 64))
 831                                        :include-args (type)))
 832
 833 (define-alien-type-translator double-float ()
 834   (make-alien-double-float-type :type 'double-float))
 835
 836 (define-alien-type-method (double-float :extract-gen) (type sap offset)
 837   (declare (ignore type))
 838   `(sap-ref-double ,sap (/ ,offset sb!vm:n-byte-bits)))
 839
 840 \f
 841 ;;;; the POINTER type
 842
 843 (define-alien-type-class (pointer :include (alien-value (bits
 844                                                          #!-alpha
 845                                                          sb!vm:n-word-bits
 846                                                          #!+alpha 64)))
 847   (to nil :type (or alien-type null)))
 848
 849 (define-alien-type-translator * (to &environment env)
 850   (make-alien-pointer-type :to (if (eq to t) nil (parse-alien-type to env))))
 851
 852 (define-alien-type-method (pointer :unparse) (type)
 853   (let ((to (alien-pointer-type-to type)))
 854     `(* ,(if to
 855              (%unparse-alien-type to)
 856              t))))
 857
 858 (define-alien-type-method (pointer :type=) (type1 type2)
 859   (let ((to1 (alien-pointer-type-to type1))
 860         (to2 (alien-pointer-type-to type2)))
 861     (if to1
 862         (if to2
 863             (alien-type-= to1 to2)
 864             nil)
 865         (null to2))))
 866
 867 (define-alien-type-method (pointer :subtypep) (type1 type2)
 868   (and (alien-pointer-type-p type2)
 869        (let ((to1 (alien-pointer-type-to type1))
 870              (to2 (alien-pointer-type-to type2)))
 871          (if to1
 872              (if to2
 873                  (alien-subtype-p to1 to2)
 874                  t)
 875              (null to2)))))
 876
 877 (define-alien-type-method (pointer :deport-gen) (type value)
 878   (/noshow "doing alien type method POINTER :DEPORT-GEN" type value)
 879   (values
 880    ;; FIXME: old version, highlighted a bug in xc optimization
 881    `(etypecase ,value
 882       (null
 883        (int-sap 0))
 884       (system-area-pointer
 885        ,value)
 886       ((alien ,type)
 887        (alien-sap ,value)))
 888    ;; new version, works around bug in xc optimization
 889    #+nil
 890    `(etypecase ,value
 891       (system-area-pointer
 892        ,value)
 893       ((alien ,type)
 894        (alien-sap ,value))
 895       (null
 896        (int-sap 0)))
 897    `(or null system-area-pointer (alien ,type))))
 898 \f
 899 ;;;; the MEM-BLOCK type
 900
 901 (define-alien-type-class (mem-block :include alien-value))
 902
 903 (define-alien-type-method (mem-block :extract-gen) (type sap offset)
 904   (declare (ignore type))
 905   `(sap+ ,sap (truncate ,offset sb!vm:n-byte-bits)))
 906
 907 (define-alien-type-method (mem-block :deposit-gen) (type sap offset value)
 908   (let ((bits (alien-mem-block-type-bits type)))
 909     (unless bits
 910       (error "can't deposit aliens of type ~S (unknown size)" type))
 911     `(sb!kernel:system-area-ub8-copy ,value 0 ,sap
 912       (truncate ,offset sb!vm:n-byte-bits)
 913       ',(truncate bits sb!vm:n-byte-bits))))
 914 \f
 915 ;;;; the ARRAY type
 916
 917 (define-alien-type-class (array :include mem-block)
 918   (element-type (missing-arg) :type alien-type)
 919   (dimensions (missing-arg) :type list))
 920
 921 (define-alien-type-translator array (ele-type &rest dims &environment env)
 922
 923   (when dims
 924     (unless (typep (first dims) '(or index null))
 925       (error "The first dimension is not a non-negative fixnum or NIL: ~S"
 926              (first dims)))
 927     (let ((loser (find-if-not (lambda (x) (typep x 'index))
 928                               (rest dims))))
 929       (when loser
 930         (error "A dimension is not a non-negative fixnum: ~S" loser))))
 931
 932   (let ((parsed-ele-type (parse-alien-type ele-type env)))
 933     (make-alien-array-type
 934      :element-type parsed-ele-type
 935      :dimensions dims
 936      :alignment (alien-type-alignment parsed-ele-type)
 937      :bits (if (and (alien-type-bits parsed-ele-type)
 938                     (every #'integerp dims))
 939                (* (align-offset (alien-type-bits parsed-ele-type)
 940                                 (alien-type-alignment parsed-ele-type))
 941                   (reduce #'* dims))))))
 942
 943 (define-alien-type-method (array :unparse) (type)
 944   `(array ,(%unparse-alien-type (alien-array-type-element-type type))
 945           ,@(alien-array-type-dimensions type)))
 946
 947 (define-alien-type-method (array :type=) (type1 type2)
 948   (and (equal (alien-array-type-dimensions type1)
 949               (alien-array-type-dimensions type2))
 950        (alien-type-= (alien-array-type-element-type type1)
 951                      (alien-array-type-element-type type2))))
 952
 953 (define-alien-type-method (array :subtypep) (type1 type2)
 954   (and (alien-array-type-p type2)
 955        (let ((dim1 (alien-array-type-dimensions type1))
 956              (dim2 (alien-array-type-dimensions type2)))
 957          (and (= (length dim1) (length dim2))
 958               (or (and dim2
 959                        (null (car dim2))
 960                        (equal (cdr dim1) (cdr dim2)))
 961                   (equal dim1 dim2))
 962               (alien-subtype-p (alien-array-type-element-type type1)
 963                                (alien-array-type-element-type type2))))))
 964 \f
 965 ;;;; the RECORD type
 966
 967 (def!struct (alien-record-field
 968              (:make-load-form-fun sb!kernel:just-dump-it-normally))
 969   (name (missing-arg) :type symbol)
 970   (type (missing-arg) :type alien-type)
 971   (bits nil :type (or unsigned-byte null))
 972   (offset 0 :type unsigned-byte))
 973 (def!method print-object ((field alien-record-field) stream)
 974   (print-unreadable-object (field stream :type t)
 975     (format stream
 976             "~S ~S~@[:~D~]"
 977             (alien-record-field-type field)
 978             (alien-record-field-name field)
 979             (alien-record-field-bits field))))
 980
 981 (define-alien-type-class (record :include mem-block)
 982   (kind :struct :type (member :struct :union))
 983   (name nil :type (or symbol null))
 984   (fields nil :type list))
 985
 986 (define-alien-type-translator struct (name &rest fields &environment env)
 987   (parse-alien-record-type :struct name fields env))
 988
 989 (define-alien-type-translator union (name &rest fields &environment env)
 990   (parse-alien-record-type :union name fields env))
 991
 992 ;;; FIXME: This is really pretty horrible: we avoid creating new
 993 ;;; ALIEN-RECORD-TYPE objects when a live one is flitting around the
 994 ;;; system already. This way forwrd-references sans fields get get
 995 ;;; "updated" for free to contain the field info. Maybe rename
 996 ;;; MAKE-ALIEN-RECORD-TYPE to %MAKE-ALIEN-RECORD-TYPE and use
 997 ;;; ENSURE-ALIEN-RECORD-TYPE instead. --NS 20040729
 998 (defun parse-alien-record-type (kind name fields env)
 999   (declare (type (or sb!kernel:lexenv null) env))
1000   (flet ((frob-type (type new-fields alignment bits)
1001            (setf (alien-record-type-fields type) new-fields
1002                  (alien-record-type-alignment type) alignment
1003                  (alien-record-type-bits type) bits)))
1004       (cond (fields
1005              (multiple-value-bind (new-fields alignment bits)
1006                  (parse-alien-record-fields kind fields env)
1007                (let* ((old (and name (auxiliary-alien-type kind name env)))
1008                       (old-fields (and old (alien-record-type-fields old))))
1009                  (when (and old-fields
1010                             (notevery #'record-fields-match-p old-fields new-fields))
1011                    (cerror "Continue, clobbering the old definition."
1012                            "Incompatible alien record type definition~%Old: ~S~%New: ~S"
1013                            (unparse-alien-type old)
1014                            `(,(unparse-alien-record-kind kind)
1015                               ,name
1016                               ,@(mapcar #'unparse-alien-record-field new-fields)))
1017                    (frob-type old new-fields alignment bits))
1018                  (if old-fields
1019                      old
1020                      (let ((type (or old (make-alien-record-type :name name :kind kind))))
1021                        (when (and name (not old))
1022                          (setf (auxiliary-alien-type kind name env) type))
1023                        (frob-type type new-fields alignment bits)
1024                        type)))))
1025             (name
1026              (or (auxiliary-alien-type kind name env)
1027                  (setf (auxiliary-alien-type kind name env)
1028                        (make-alien-record-type :name name :kind kind))))
1029             (t
1030              (make-alien-record-type :kind kind)))))
1031
1032 ;;; This is used by PARSE-ALIEN-TYPE to parse the fields of struct and union
1033 ;;; types. KIND is the kind we are paring the fields of, and FIELDS is the
1034 ;;; list of field specifications.
1035 ;;;
1036 ;;; Result is a list of field objects, overall alignment, and number of bits
1037 (defun parse-alien-record-fields (kind fields env)
1038   (declare (type list fields))
1039   (let ((total-bits 0)
1040         (overall-alignment 1)
1041         (parsed-fields nil))
1042     (dolist (field fields)
1043       (destructuring-bind (var type &key alignment) field
1044         (let* ((field-type (parse-alien-type type env))
1045                (bits (alien-type-bits field-type))
1046                (parsed-field
1047                 (make-alien-record-field :type field-type
1048                                          :name var)))
1049           (unless alignment
1050             (setf alignment (alien-type-alignment field-type)))
1051           (push parsed-field parsed-fields)
1052           (when (null bits)
1053             (error "unknown size: ~S" (unparse-alien-type field-type)))
1054           (when (null alignment)
1055             (error "unknown alignment: ~S" (unparse-alien-type field-type)))
1056           (setf overall-alignment (max overall-alignment alignment))
1057           (ecase kind
1058             (:struct
1059              (let ((offset (align-offset total-bits alignment)))
1060                (setf (alien-record-field-offset parsed-field) offset)
1061                (setf total-bits (+ offset bits))))
1062             (:union
1063              (setf total-bits (max total-bits bits)))))))
1064     (values (nreverse parsed-fields)
1065             overall-alignment
1066             (align-offset total-bits overall-alignment))))
1067
1068 (define-alien-type-method (record :unparse) (type)
1069   `(,(unparse-alien-record-kind (alien-record-type-kind type))
1070     ,(alien-record-type-name type)
1071     ,@(unless (member type *record-types-already-unparsed* :test #'eq)
1072         (push type *record-types-already-unparsed*)
1073         (mapcar #'unparse-alien-record-field
1074                 (alien-record-type-fields type)))))
1075
1076 (defun unparse-alien-record-kind (kind)
1077   (case kind
1078     (:struct 'struct)
1079     (:union 'union)
1080     (t '???)))
1081
1082 (defun unparse-alien-record-field (field)
1083   `(,(alien-record-field-name field)
1084      ,(%unparse-alien-type (alien-record-field-type field))
1085      ,@(when (alien-record-field-bits field)
1086              (list (alien-record-field-bits field)))))
1087
1088 ;;; Test the record fields. Keep a hashtable table of already compared
1089 ;;; types to detect cycles.
1090 (defun record-fields-match-p (field1 field2)
1091   (and (eq (alien-record-field-name field1)
1092            (alien-record-field-name field2))
1093        (eql (alien-record-field-bits field1)
1094             (alien-record-field-bits field2))
1095        (eql (alien-record-field-offset field1)
1096             (alien-record-field-offset field2))
1097        (alien-type-= (alien-record-field-type field1)
1098                      (alien-record-field-type field2))))
1099
1100 (defvar *alien-type-matches* nil
1101   "A hashtable used to detect cycles while comparing record types.")
1102
1103 (define-alien-type-method (record :type=) (type1 type2)
1104   (and (eq (alien-record-type-name type1)
1105            (alien-record-type-name type2))
1106        (eq (alien-record-type-kind type1)
1107            (alien-record-type-kind type2))
1108        (eql (alien-type-bits type1)
1109             (alien-type-bits type2))
1110        (eql (alien-type-alignment type1)
1111             (alien-type-alignment type2))
1112        (flet ((match-fields (&optional old)
1113                 (setf (gethash type1 *alien-type-matches*) (cons type2 old))
1114                 (every #'record-fields-match-p
1115                        (alien-record-type-fields type1)
1116                        (alien-record-type-fields type2))))
1117          (if *alien-type-matches*
1118              (let ((types (gethash type1 *alien-type-matches*)))
1119                (or (memq type2 types) (match-fields types)))
1120              (let ((*alien-type-matches* (make-hash-table :test #'eq)))
1121                (match-fields))))))
1122 \f
1123 ;;;; the FUNCTION and VALUES alien types
1124
1125 (define-alien-type-class (fun :include mem-block)
1126   (result-type (missing-arg) :type alien-type)
1127   (arg-types (missing-arg) :type list)
1128   (stub nil :type (or null function)))
1129
1130 (define-alien-type-translator function (result-type &rest arg-types
1131                                                     &environment env)
1132   (make-alien-fun-type
1133    :result-type (let ((*values-type-okay* t))
1134                   (parse-alien-type result-type env))
1135    :arg-types (mapcar (lambda (arg-type) (parse-alien-type arg-type env))
1136                       arg-types)))
1137
1138 (define-alien-type-method (fun :unparse) (type)
1139   `(function ,(%unparse-alien-type (alien-fun-type-result-type type))
1140              ,@(mapcar #'%unparse-alien-type
1141                        (alien-fun-type-arg-types type))))
1142
1143 (define-alien-type-method (fun :type=) (type1 type2)
1144   (and (alien-type-= (alien-fun-type-result-type type1)
1145                      (alien-fun-type-result-type type2))
1146        (= (length (alien-fun-type-arg-types type1))
1147           (length (alien-fun-type-arg-types type2)))
1148        (every #'alien-type-=
1149               (alien-fun-type-arg-types type1)
1150               (alien-fun-type-arg-types type2))))
1151
1152 (define-alien-type-class (values)
1153   (values (missing-arg) :type list))
1154
1155 (define-alien-type-translator values (&rest values &environment env)
1156   (unless *values-type-okay*
1157     (error "cannot use values types here"))
1158   (let ((*values-type-okay* nil))
1159     (make-alien-values-type
1160      :values (mapcar (lambda (alien-type) (parse-alien-type alien-type env))
1161                      values))))
1162
1163 (define-alien-type-method (values :unparse) (type)
1164   `(values ,@(mapcar #'%unparse-alien-type
1165                      (alien-values-type-values type))))
1166
1167 (define-alien-type-method (values :type=) (type1 type2)
1168   (and (= (length (alien-values-type-values type1))
1169           (length (alien-values-type-values type2)))
1170        (every #'alien-type-=
1171               (alien-values-type-values type1)
1172               (alien-values-type-values type2))))
1173 \f
1174 ;;;; a structure definition needed both in the target and in the
1175 ;;;; cross-compilation host
1176
1177 ;;; information about local aliens. The WITH-ALIEN macro builds one of
1178 ;;; these structures and LOCAL-ALIEN and friends communicate
1179 ;;; information about how that local alien is represented.
1180 (def!struct (local-alien-info
1181              (:make-load-form-fun sb!kernel:just-dump-it-normally)
1182              (:constructor make-local-alien-info
1183                            (&key type force-to-memory-p
1184                             &aux (force-to-memory-p (or force-to-memory-p
1185                                                         (alien-array-type-p type)
1186                                                         (alien-record-type-p type))))))
1187   ;; the type of the local alien
1188   (type (missing-arg) :type alien-type)
1189   ;; Must this local alien be forced into memory? Using the ADDR macro
1190   ;; on a local alien will set this.
1191   (force-to-memory-p nil :type (member t nil)))
1192 (def!method print-object ((info local-alien-info) stream)
1193   (print-unreadable-object (info stream :type t)
1194     (format stream
1195             "~:[~;(forced to stack) ~]~S"
1196             (local-alien-info-force-to-memory-p info)
1197             (unparse-alien-type (local-alien-info-type info)))))
1198 \f
1199 ;;;; the ADDR macro
1200
1201 (defmacro-mundanely addr (expr &environment env)
1202   #!+sb-doc
1203   "Return an Alien pointer to the data addressed by Expr, which must be a call
1204    to SLOT or DEREF, or a reference to an Alien variable."
1205   (let ((form (sb!xc:macroexpand expr env)))
1206     (or (typecase form
1207           (cons
1208            (case (car form)
1209              (slot
1210               (cons '%slot-addr (cdr form)))
1211              (deref
1212               (cons '%deref-addr (cdr form)))
1213              (%heap-alien
1214               (cons '%heap-alien-addr (cdr form)))
1215              (local-alien
1216               (let ((info (let ((info-arg (second form)))
1217                             (and (consp info-arg)
1218                                  (eq (car info-arg) 'quote)
1219                                  (second info-arg)))))
1220                 (unless (local-alien-info-p info)
1221                   (error "Something is wrong, LOCAL-ALIEN-INFO not found: ~S"
1222                          form))
1223                 (setf (local-alien-info-force-to-memory-p info) t))
1224               (cons '%local-alien-addr (cdr form)))))
1225           (symbol
1226            (let ((kind (info :variable :kind form)))
1227              (when (eq kind :alien)
1228                `(%heap-alien-addr ',(info :variable :alien-info form))))))
1229         (error "~S is not a valid L-value." form))))
1230
1231 (/show0 "host-alieneval.lisp end of file")