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)
 368   (declare (ignore type))
 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 (defun compute-alien-rep-type (type)
 506   (invoke-alien-type-method :alien-rep type))
 507 \f
 508 ;;;; default methods
 509
 510 (define-alien-type-method (root :unparse) (type)
 511   `(<unknown-alien-type> ,(type-of type)))
 512
 513 (define-alien-type-method (root :type=) (type1 type2)
 514   (declare (ignore type1 type2))
 515   t)
 516
 517 (define-alien-type-method (root :subtypep) (type1 type2)
 518   (alien-type-= type1 type2))
 519
 520 (define-alien-type-method (root :lisp-rep) (type)
 521   (declare (ignore type))
 522   nil)
 523
 524 (define-alien-type-method (root :alien-rep) (type)
 525   (declare (ignore type))
 526   '*)
 527
 528 (define-alien-type-method (root :naturalize-gen) (type alien)
 529   (declare (ignore alien))
 530   (error "cannot represent ~S typed aliens" type))
 531
 532 (define-alien-type-method (root :deport-gen) (type object)
 533   (declare (ignore object))
 534   (error "cannot represent ~S typed aliens" type))
 535
 536 (define-alien-type-method (root :deport-alloc-gen) (type object)
 537   (declare (ignore type))
 538   object)
 539
 540 (define-alien-type-method (root :deport-pin-p) (type)
 541   (declare (ignore type))
 542   ;; Override this method to return T for classes which take a SAP to a
 543   ;; GCable lisp object when deporting.
 544   nil)
 545
 546 (define-alien-type-method (root :extract-gen) (type sap offset)
 547   (declare (ignore sap offset))
 548   (error "cannot represent ~S typed aliens" type))
 549
 550 (define-alien-type-method (root :deposit-gen) (type sap offset value)
 551   `(setf ,(invoke-alien-type-method :extract-gen type sap offset) ,value))
 552
 553 (define-alien-type-method (root :arg-tn) (type state)
 554   (declare (ignore state))
 555   (error "Aliens of type ~S cannot be passed as arguments to CALL-OUT."
 556          (unparse-alien-type type)))
 557
 558 (define-alien-type-method (root :result-tn) (type state)
 559   (declare (ignore state))
 560   (error "Aliens of type ~S cannot be returned from CALL-OUT."
 561          (unparse-alien-type type)))
 562 \f
 563 ;;;; the INTEGER type
 564
 565 (define-alien-type-class (integer)
 566   (signed t :type (member t nil)))
 567
 568 (define-alien-type-translator signed (&optional (bits sb!vm:n-word-bits))
 569   (make-alien-integer-type :bits bits))
 570
 571 (define-alien-type-translator integer (&optional (bits sb!vm:n-word-bits))
 572   (make-alien-integer-type :bits bits))
 573
 574 (define-alien-type-translator unsigned (&optional (bits sb!vm:n-word-bits))
 575   (make-alien-integer-type :bits bits :signed nil))
 576
 577 (define-alien-type-method (integer :unparse) (type)
 578   (list (if (alien-integer-type-signed type) 'signed 'unsigned)
 579         (alien-integer-type-bits type)))
 580
 581 (define-alien-type-method (integer :type=) (type1 type2)
 582   (and (eq (alien-integer-type-signed type1)
 583            (alien-integer-type-signed type2))
 584        (= (alien-integer-type-bits type1)
 585           (alien-integer-type-bits type2))))
 586
 587 (define-alien-type-method (integer :lisp-rep) (type)
 588   (list (if (alien-integer-type-signed type) 'signed-byte 'unsigned-byte)
 589         (alien-integer-type-bits type)))
 590
 591 (define-alien-type-method (integer :alien-rep) (type)
 592   (list (if (alien-integer-type-signed type) 'signed-byte 'unsigned-byte)
 593         (alien-integer-type-bits type)))
 594
 595 (define-alien-type-method (integer :naturalize-gen) (type alien)
 596   (declare (ignore type))
 597   alien)
 598
 599 (define-alien-type-method (integer :deport-gen) (type value)
 600   (declare (ignore type))
 601   value)
 602
 603 (define-alien-type-method (integer :extract-gen) (type sap offset)
 604   (declare (type alien-integer-type type))
 605   (let ((ref-fun
 606          (if (alien-integer-type-signed type)
 607           (case (alien-integer-type-bits type)
 608             (8 'signed-sap-ref-8)
 609             (16 'signed-sap-ref-16)
 610             (32 'signed-sap-ref-32)
 611             (64 'signed-sap-ref-64))
 612           (case (alien-integer-type-bits type)
 613             (8 'sap-ref-8)
 614             (16 'sap-ref-16)
 615             (32 'sap-ref-32)
 616             (64 'sap-ref-64)))))
 617     (if ref-fun
 618         `(,ref-fun ,sap (/ ,offset sb!vm:n-byte-bits))
 619         (error "cannot extract ~W-bit integers"
 620                (alien-integer-type-bits type)))))
 621 \f
 622 ;;;; the BOOLEAN type
 623
 624 (define-alien-type-class (boolean :include integer :include-args (signed)))
 625
 626 ;;; FIXME: Check to make sure that we aren't attaching user-readable
 627 ;;; stuff to CL:BOOLEAN in any way which impairs ANSI compliance.
 628 (define-alien-type-translator boolean (&optional (bits sb!vm:n-word-bits))
 629   (make-alien-boolean-type :bits bits :signed nil))
 630
 631 (define-alien-type-method (boolean :unparse) (type)
 632   `(boolean ,(alien-boolean-type-bits type)))
 633
 634 (define-alien-type-method (boolean :lisp-rep) (type)
 635   (declare (ignore type))
 636   `(member t nil))
 637
 638 (define-alien-type-method (boolean :naturalize-gen) (type alien)
 639   (declare (ignore type))
 640   `(not (zerop ,alien)))
 641
 642 (define-alien-type-method (boolean :deport-gen) (type value)
 643   (declare (ignore type))
 644   `(if ,value 1 0))
 645 \f
 646 ;;;; the ENUM type
 647
 648 (define-alien-type-class (enum :include (integer (bits 32))
 649                                :include-args (signed))
 650   name          ; name of this enum (if any)
 651   from          ; alist from symbols to integers
 652   to            ; alist or vector from integers to symbols
 653   kind          ; kind of from mapping, :VECTOR or :ALIST
 654   offset)       ; offset to add to value for :VECTOR from mapping
 655
 656 (define-alien-type-translator enum (&whole
 657                                  type name
 658                                  &rest mappings
 659                                  &environment env)
 660   (cond (mappings
 661          (let ((result (parse-enum name mappings)))
 662            (when name
 663              (multiple-value-bind (old old-p)
 664                  (auxiliary-alien-type :enum name env)
 665                (when old-p
 666                  (unless (alien-type-= result old)
 667                    (cerror "Continue, clobbering the old definition"
 668                            "Incompatible alien enum type definition: ~S" name)
 669                    (setf (alien-type-from old) (alien-type-from result)
 670                          (alien-type-to old) (alien-type-to result)
 671                          (alien-type-kind old) (alien-type-kind result)
 672                          (alien-type-offset old) (alien-type-offset result)
 673                          (alien-type-signed old) (alien-type-signed result)))
 674                  (setf result old))
 675                (unless old-p
 676                  (setf (auxiliary-alien-type :enum name env) result))))
 677            result))
 678         (name
 679          (multiple-value-bind (result found)
 680              (auxiliary-alien-type :enum name env)
 681            (unless found
 682              (error "unknown enum type: ~S" name))
 683            result))
 684         (t
 685          (error "empty enum type: ~S" type))))
 686
 687 (defun parse-enum (name elements)
 688   (when (null elements)
 689     (error "An enumeration must contain at least one element."))
 690   (let ((min nil)
 691         (max nil)
 692         (from-alist ())
 693         (prev -1))
 694     (declare (list from-alist))
 695     (dolist (el elements)
 696       (multiple-value-bind (sym val)
 697           (if (listp el)
 698               (values (first el) (second el))
 699               (values el (1+ prev)))
 700         (setf prev val)
 701         (unless (symbolp sym)
 702           (error "The enumeration element ~S is not a symbol." sym))
 703         (unless (integerp val)
 704           (error "The element value ~S is not an integer." val))
 705         (unless (and max (> max val)) (setq max val))
 706         (unless (and min (< min val)) (setq min val))
 707         (when (rassoc val from-alist)
 708           (style-warn "The element value ~S is used more than once." val))
 709         (when (assoc sym from-alist :test #'eq)
 710           (error "The enumeration element ~S is used more than once." sym))
 711         (push (cons sym val) from-alist)))
 712     (let* ((signed (minusp min))
 713            (min-bits (if signed
 714                          (1+ (max (integer-length min)
 715                                   (integer-length max)))
 716                          (integer-length max))))
 717       (when (> min-bits 32)
 718         (error "can't represent enums needing more than 32 bits"))
 719       (setf from-alist (sort from-alist #'< :key #'cdr))
 720       (cond
 721        ;; If range is at least 20% dense, use vector mapping. Crossover
 722        ;; point solely on basis of space would be 25%. Vector mapping
 723        ;; is always faster, so give the benefit of the doubt.
 724        ((< 0.2 (/ (float (length from-alist)) (float (1+ (- max min)))))
 725         ;; If offset is small and ignorable, ignore it to save time.
 726         (when (< 0 min 10) (setq min 0))
 727         (let ((to (make-array (1+ (- max min)))))
 728           (dolist (el from-alist)
 729             (setf (svref to (- (cdr el) min)) (car el)))
 730           (make-alien-enum-type :name name :signed signed
 731                                 :from from-alist :to to :kind
 732                                 :vector :offset (- min))))
 733        (t
 734         (make-alien-enum-type :name name :signed signed
 735                               :from from-alist
 736                               :to (mapcar (lambda (x) (cons (cdr x) (car x)))
 737                                           from-alist)
 738                               :kind :alist))))))
 739
 740 (define-alien-type-method (enum :unparse) (type)
 741   `(enum ,(alien-enum-type-name type)
 742          ,@(let ((prev -1))
 743              (mapcar (lambda (mapping)
 744                        (let ((sym (car mapping))
 745                              (value (cdr mapping)))
 746                          (prog1
 747                              (if (= (1+ prev) value)
 748                                  sym
 749                                  `(,sym ,value))
 750                            (setf prev value))))
 751                      (alien-enum-type-from type)))))
 752
 753 (define-alien-type-method (enum :type=) (type1 type2)
 754   (and (eq (alien-enum-type-name type1)
 755            (alien-enum-type-name type2))
 756        (equal (alien-enum-type-from type1)
 757               (alien-enum-type-from type2))))
 758
 759 (define-alien-type-method (enum :lisp-rep) (type)
 760   `(member ,@(mapcar #'car (alien-enum-type-from type))))
 761
 762 (define-alien-type-method (enum :naturalize-gen) (type alien)
 763   (ecase (alien-enum-type-kind type)
 764     (:vector
 765      `(svref ',(alien-enum-type-to type)
 766              (+ ,alien ,(alien-enum-type-offset type))))
 767     (:alist
 768      `(ecase ,alien
 769         ,@(mapcar (lambda (mapping)
 770                     `(,(car mapping) ',(cdr mapping)))
 771                   (alien-enum-type-to type))))))
 772
 773 (define-alien-type-method (enum :deport-gen) (type value)
 774   `(ecase ,value
 775      ,@(mapcar (lambda (mapping)
 776                  `(,(car mapping) ,(cdr mapping)))
 777                (alien-enum-type-from type))))
 778 \f
 779 ;;;; the FLOAT types
 780
 781 (define-alien-type-class (float)
 782   (type (missing-arg) :type symbol))
 783
 784 (define-alien-type-method (float :unparse) (type)
 785   (alien-float-type-type type))
 786
 787 (define-alien-type-method (float :lisp-rep) (type)
 788   (alien-float-type-type type))
 789
 790 (define-alien-type-method (float :alien-rep) (type)
 791   (alien-float-type-type type))
 792
 793 (define-alien-type-method (float :naturalize-gen) (type alien)
 794   (declare (ignore type))
 795   alien)
 796
 797 (define-alien-type-method (float :deport-gen) (type value)
 798   (declare (ignore type))
 799   value)
 800
 801 (define-alien-type-class (single-float :include (float (bits 32))
 802                                        :include-args (type)))
 803
 804 (define-alien-type-translator single-float ()
 805   (make-alien-single-float-type :type 'single-float))
 806
 807 (define-alien-type-method (single-float :extract-gen) (type sap offset)
 808   (declare (ignore type))
 809   `(sap-ref-single ,sap (/ ,offset sb!vm:n-byte-bits)))
 810
 811 (define-alien-type-class (double-float :include (float (bits 64))
 812                                        :include-args (type)))
 813
 814 (define-alien-type-translator double-float ()
 815   (make-alien-double-float-type :type 'double-float))
 816
 817 (define-alien-type-method (double-float :extract-gen) (type sap offset)
 818   (declare (ignore type))
 819   `(sap-ref-double ,sap (/ ,offset sb!vm:n-byte-bits)))
 820
 821 \f
 822 ;;;; the POINTER type
 823
 824 (define-alien-type-class (pointer :include (alien-value (bits
 825                                                          #!-alpha
 826                                                          sb!vm:n-word-bits
 827                                                          #!+alpha 64)))
 828   (to nil :type (or alien-type null)))
 829
 830 (define-alien-type-translator * (to &environment env)
 831   (make-alien-pointer-type :to (if (eq to t) nil (parse-alien-type to env))))
 832
 833 (define-alien-type-method (pointer :unparse) (type)
 834   (let ((to (alien-pointer-type-to type)))
 835     `(* ,(if to
 836              (%unparse-alien-type to)
 837              t))))
 838
 839 (define-alien-type-method (pointer :type=) (type1 type2)
 840   (let ((to1 (alien-pointer-type-to type1))
 841         (to2 (alien-pointer-type-to type2)))
 842     (if to1
 843         (if to2
 844             (alien-type-= to1 to2)
 845             nil)
 846         (null to2))))
 847
 848 (define-alien-type-method (pointer :subtypep) (type1 type2)
 849   (and (alien-pointer-type-p type2)
 850        (let ((to1 (alien-pointer-type-to type1))
 851              (to2 (alien-pointer-type-to type2)))
 852          (if to1
 853              (if to2
 854                  (alien-subtype-p to1 to2)
 855                  t)
 856              (null to2)))))
 857
 858 (define-alien-type-method (pointer :deport-gen) (type value)
 859   (/noshow "doing alien type method POINTER :DEPORT-GEN" type value)
 860   (values
 861    ;; FIXME: old version, highlighted a bug in xc optimization
 862    `(etypecase ,value
 863       (null
 864        (int-sap 0))
 865       (system-area-pointer
 866        ,value)
 867       ((alien ,type)
 868        (alien-sap ,value)))
 869    ;; new version, works around bug in xc optimization
 870    #+nil
 871    `(etypecase ,value
 872       (system-area-pointer
 873        ,value)
 874       ((alien ,type)
 875        (alien-sap ,value))
 876       (null
 877        (int-sap 0)))
 878    `(or null system-area-pointer (alien ,type))))
 879 \f
 880 ;;;; the MEM-BLOCK type
 881
 882 (define-alien-type-class (mem-block :include alien-value))
 883
 884 (define-alien-type-method (mem-block :extract-gen) (type sap offset)
 885   (declare (ignore type))
 886   `(sap+ ,sap (truncate ,offset sb!vm:n-byte-bits)))
 887
 888 (define-alien-type-method (mem-block :deposit-gen) (type sap offset value)
 889   (let ((bits (alien-mem-block-type-bits type)))
 890     (unless bits
 891       (error "can't deposit aliens of type ~S (unknown size)" type))
 892     `(sb!kernel:system-area-ub8-copy ,value 0 ,sap
 893       (truncate ,offset sb!vm:n-byte-bits)
 894       ',(truncate bits sb!vm:n-byte-bits))))
 895 \f
 896 ;;;; the ARRAY type
 897
 898 (define-alien-type-class (array :include mem-block)
 899   (element-type (missing-arg) :type alien-type)
 900   (dimensions (missing-arg) :type list))
 901
 902 (define-alien-type-translator array (ele-type &rest dims &environment env)
 903
 904   (when dims
 905     (unless (typep (first dims) '(or index null))
 906       (error "The first dimension is not a non-negative fixnum or NIL: ~S"
 907              (first dims)))
 908     (let ((loser (find-if-not (lambda (x) (typep x 'index))
 909                               (rest dims))))
 910       (when loser
 911         (error "A dimension is not a non-negative fixnum: ~S" loser))))
 912
 913   (let ((parsed-ele-type (parse-alien-type ele-type env)))
 914     (make-alien-array-type
 915      :element-type parsed-ele-type
 916      :dimensions dims
 917      :alignment (alien-type-alignment parsed-ele-type)
 918      :bits (if (and (alien-type-bits parsed-ele-type)
 919                     (every #'integerp dims))
 920                (* (align-offset (alien-type-bits parsed-ele-type)
 921                                 (alien-type-alignment parsed-ele-type))
 922                   (reduce #'* dims))))))
 923
 924 (define-alien-type-method (array :unparse) (type)
 925   `(array ,(%unparse-alien-type (alien-array-type-element-type type))
 926           ,@(alien-array-type-dimensions type)))
 927
 928 (define-alien-type-method (array :type=) (type1 type2)
 929   (and (equal (alien-array-type-dimensions type1)
 930               (alien-array-type-dimensions type2))
 931        (alien-type-= (alien-array-type-element-type type1)
 932                      (alien-array-type-element-type type2))))
 933
 934 (define-alien-type-method (array :subtypep) (type1 type2)
 935   (and (alien-array-type-p type2)
 936        (let ((dim1 (alien-array-type-dimensions type1))
 937              (dim2 (alien-array-type-dimensions type2)))
 938          (and (= (length dim1) (length dim2))
 939               (or (and dim2
 940                        (null (car dim2))
 941                        (equal (cdr dim1) (cdr dim2)))
 942                   (equal dim1 dim2))
 943               (alien-subtype-p (alien-array-type-element-type type1)
 944                                (alien-array-type-element-type type2))))))
 945 \f
 946 ;;;; the RECORD type
 947
 948 (def!struct (alien-record-field
 949              (:make-load-form-fun sb!kernel:just-dump-it-normally))
 950   (name (missing-arg) :type symbol)
 951   (type (missing-arg) :type alien-type)
 952   (bits nil :type (or unsigned-byte null))
 953   (offset 0 :type unsigned-byte))
 954 (def!method print-object ((field alien-record-field) stream)
 955   (print-unreadable-object (field stream :type t)
 956     (format stream
 957             "~S ~S~@[:~D~]"
 958             (alien-record-field-type field)
 959             (alien-record-field-name field)
 960             (alien-record-field-bits field))))
 961
 962 (define-alien-type-class (record :include mem-block)
 963   (kind :struct :type (member :struct :union))
 964   (name nil :type (or symbol null))
 965   (fields nil :type list))
 966
 967 (define-alien-type-translator struct (name &rest fields &environment env)
 968   (parse-alien-record-type :struct name fields env))
 969
 970 (define-alien-type-translator union (name &rest fields &environment env)
 971   (parse-alien-record-type :union name fields env))
 972
 973 ;;; FIXME: This is really pretty horrible: we avoid creating new
 974 ;;; ALIEN-RECORD-TYPE objects when a live one is flitting around the
 975 ;;; system already. This way forwrd-references sans fields get get
 976 ;;; "updated" for free to contain the field info. Maybe rename
 977 ;;; MAKE-ALIEN-RECORD-TYPE to %MAKE-ALIEN-RECORD-TYPE and use
 978 ;;; ENSURE-ALIEN-RECORD-TYPE instead. --NS 20040729
 979 (defun parse-alien-record-type (kind name fields env)
 980   (declare (type (or sb!kernel:lexenv null) env))
 981   (flet ((frob-type (type new-fields alignment bits)
 982            (setf (alien-record-type-fields type) new-fields
 983                  (alien-record-type-alignment type) alignment
 984                  (alien-record-type-bits type) bits)))
 985       (cond (fields
 986              (multiple-value-bind (new-fields alignment bits)
 987                  (parse-alien-record-fields kind fields env)
 988                (let* ((old (and name (auxiliary-alien-type kind name env)))
 989                       (old-fields (and old (alien-record-type-fields old))))
 990                  (when (and old-fields
 991                             (notevery #'record-fields-match-p old-fields new-fields))
 992                    (cerror "Continue, clobbering the old definition."
 993                            "Incompatible alien record type definition~%Old: ~S~%New: ~S"
 994                            (unparse-alien-type old)
 995                            `(,(unparse-alien-record-kind kind)
 996                               ,name
 997                               ,@(mapcar #'unparse-alien-record-field new-fields)))
 998                    (frob-type old new-fields alignment bits))
 999                  (if old-fields
1000                      old
1001                      (let ((type (or old (make-alien-record-type :name name :kind kind))))
1002                        (when (and name (not old))
1003                          (setf (auxiliary-alien-type kind name env) type))
1004                        (frob-type type new-fields alignment bits)
1005                        type)))))
1006             (name
1007              (or (auxiliary-alien-type kind name env)
1008                  (setf (auxiliary-alien-type kind name env)
1009                        (make-alien-record-type :name name :kind kind))))
1010             (t
1011              (make-alien-record-type :kind kind)))))
1012
1013 ;;; This is used by PARSE-ALIEN-TYPE to parse the fields of struct and union
1014 ;;; types. KIND is the kind we are paring the fields of, and FIELDS is the
1015 ;;; list of field specifications.
1016 ;;;
1017 ;;; Result is a list of field objects, overall alignment, and number of bits
1018 (defun parse-alien-record-fields (kind fields env)
1019   (declare (type list fields))
1020   (let ((total-bits 0)
1021         (overall-alignment 1)
1022         (parsed-fields nil))
1023     (dolist (field fields)
1024       (destructuring-bind (var type &key alignment) field
1025         (let* ((field-type (parse-alien-type type env))
1026                (bits (alien-type-bits field-type))
1027                (parsed-field
1028                 (make-alien-record-field :type field-type
1029                                          :name var)))
1030           (unless alignment
1031             (setf alignment (alien-type-alignment field-type)))
1032           (push parsed-field parsed-fields)
1033           (when (null bits)
1034             (error "unknown size: ~S" (unparse-alien-type field-type)))
1035           (when (null alignment)
1036             (error "unknown alignment: ~S" (unparse-alien-type field-type)))
1037           (setf overall-alignment (max overall-alignment alignment))
1038           (ecase kind
1039             (:struct
1040              (let ((offset (align-offset total-bits alignment)))
1041                (setf (alien-record-field-offset parsed-field) offset)
1042                (setf total-bits (+ offset bits))))
1043             (:union
1044              (setf total-bits (max total-bits bits)))))))
1045     (values (nreverse parsed-fields)
1046             overall-alignment
1047             (align-offset total-bits overall-alignment))))
1048
1049 (define-alien-type-method (record :unparse) (type)
1050   `(,(unparse-alien-record-kind (alien-record-type-kind type))
1051     ,(alien-record-type-name type)
1052     ,@(unless (member type *record-types-already-unparsed* :test #'eq)
1053         (push type *record-types-already-unparsed*)
1054         (mapcar #'unparse-alien-record-field
1055                 (alien-record-type-fields type)))))
1056
1057 (defun unparse-alien-record-kind (kind)
1058   (case kind
1059     (:struct 'struct)
1060     (:union 'union)
1061     (t '???)))
1062
1063 (defun unparse-alien-record-field (field)
1064   `(,(alien-record-field-name field)
1065      ,(%unparse-alien-type (alien-record-field-type field))
1066      ,@(when (alien-record-field-bits field)
1067              (list (alien-record-field-bits field)))))
1068
1069 ;;; Test the record fields. Keep a hashtable table of already compared
1070 ;;; types to detect cycles.
1071 (defun record-fields-match-p (field1 field2)
1072   (and (eq (alien-record-field-name field1)
1073            (alien-record-field-name field2))
1074        (eql (alien-record-field-bits field1)
1075             (alien-record-field-bits field2))
1076        (eql (alien-record-field-offset field1)
1077             (alien-record-field-offset field2))
1078        (alien-type-= (alien-record-field-type field1)
1079                      (alien-record-field-type field2))))
1080
1081 (defvar *alien-type-matches* nil
1082   "A hashtable used to detect cycles while comparing record types.")
1083
1084 (define-alien-type-method (record :type=) (type1 type2)
1085   (and (eq (alien-record-type-name type1)
1086            (alien-record-type-name type2))
1087        (eq (alien-record-type-kind type1)
1088            (alien-record-type-kind type2))
1089        (eql (alien-type-bits type1)
1090             (alien-type-bits type2))
1091        (eql (alien-type-alignment type1)
1092             (alien-type-alignment type2))
1093        (flet ((match-fields (&optional old)
1094                 (setf (gethash type1 *alien-type-matches*) (cons type2 old))
1095                 (every #'record-fields-match-p
1096                        (alien-record-type-fields type1)
1097                        (alien-record-type-fields type2))))
1098          (if *alien-type-matches*
1099              (let ((types (gethash type1 *alien-type-matches*)))
1100                (or (memq type2 types) (match-fields types)))
1101              (let ((*alien-type-matches* (make-hash-table :test #'eq)))
1102                (match-fields))))))
1103 \f
1104 ;;;; the FUNCTION and VALUES alien types
1105
1106 (define-alien-type-class (fun :include mem-block)
1107   (result-type (missing-arg) :type alien-type)
1108   (arg-types (missing-arg) :type list)
1109   (stub nil :type (or null function)))
1110
1111 (define-alien-type-translator function (result-type &rest arg-types
1112                                                     &environment env)
1113   (make-alien-fun-type
1114    :result-type (let ((*values-type-okay* t))
1115                   (parse-alien-type result-type env))
1116    :arg-types (mapcar (lambda (arg-type) (parse-alien-type arg-type env))
1117                       arg-types)))
1118
1119 (define-alien-type-method (fun :unparse) (type)
1120   `(function ,(%unparse-alien-type (alien-fun-type-result-type type))
1121              ,@(mapcar #'%unparse-alien-type
1122                        (alien-fun-type-arg-types type))))
1123
1124 (define-alien-type-method (fun :type=) (type1 type2)
1125   (and (alien-type-= (alien-fun-type-result-type type1)
1126                      (alien-fun-type-result-type type2))
1127        (= (length (alien-fun-type-arg-types type1))
1128           (length (alien-fun-type-arg-types type2)))
1129        (every #'alien-type-=
1130               (alien-fun-type-arg-types type1)
1131               (alien-fun-type-arg-types type2))))
1132
1133 (define-alien-type-class (values)
1134   (values (missing-arg) :type list))
1135
1136 (define-alien-type-translator values (&rest values &environment env)
1137   (unless *values-type-okay*
1138     (error "cannot use values types here"))
1139   (let ((*values-type-okay* nil))
1140     (make-alien-values-type
1141      :values (mapcar (lambda (alien-type) (parse-alien-type alien-type env))
1142                      values))))
1143
1144 (define-alien-type-method (values :unparse) (type)
1145   `(values ,@(mapcar #'%unparse-alien-type
1146                      (alien-values-type-values type))))
1147
1148 (define-alien-type-method (values :type=) (type1 type2)
1149   (and (= (length (alien-values-type-values type1))
1150           (length (alien-values-type-values type2)))
1151        (every #'alien-type-=
1152               (alien-values-type-values type1)
1153               (alien-values-type-values type2))))
1154 \f
1155 ;;;; a structure definition needed both in the target and in the
1156 ;;;; cross-compilation host
1157
1158 ;;; information about local aliens. The WITH-ALIEN macro builds one of
1159 ;;; these structures and LOCAL-ALIEN and friends communicate
1160 ;;; information about how that local alien is represented.
1161 (def!struct (local-alien-info
1162              (:make-load-form-fun sb!kernel:just-dump-it-normally)
1163              (:constructor make-local-alien-info
1164                            (&key type force-to-memory-p
1165                             &aux (force-to-memory-p (or force-to-memory-p
1166                                                         (alien-array-type-p type)
1167                                                         (alien-record-type-p type))))))
1168   ;; the type of the local alien
1169   (type (missing-arg) :type alien-type)
1170   ;; Must this local alien be forced into memory? Using the ADDR macro
1171   ;; on a local alien will set this.
1172   (force-to-memory-p nil :type (member t nil)))
1173 (def!method print-object ((info local-alien-info) stream)
1174   (print-unreadable-object (info stream :type t)
1175     (format stream
1176             "~:[~;(forced to stack) ~]~S"
1177             (local-alien-info-force-to-memory-p info)
1178             (unparse-alien-type (local-alien-info-type info)))))
1179 \f
1180 ;;;; the ADDR macro
1181
1182 (defmacro-mundanely addr (expr &environment env)
1183   #!+sb-doc
1184   "Return an Alien pointer to the data addressed by Expr, which must be a call
1185    to SLOT or DEREF, or a reference to an Alien variable."
1186   (let ((form (sb!xc:macroexpand expr env)))
1187     (or (typecase form
1188           (cons
1189            (case (car form)
1190              (slot
1191               (cons '%slot-addr (cdr form)))
1192              (deref
1193               (cons '%deref-addr (cdr form)))
1194              (%heap-alien
1195               (cons '%heap-alien-addr (cdr form)))
1196              (local-alien
1197               (let ((info (let ((info-arg (second form)))
1198                             (and (consp info-arg)
1199                                  (eq (car info-arg) 'quote)
1200                                  (second info-arg)))))
1201                 (unless (local-alien-info-p info)
1202                   (error "Something is wrong, LOCAL-ALIEN-INFO not found: ~S"
1203                          form))
1204                 (setf (local-alien-info-force-to-memory-p info) t))
1205               (cons '%local-alien-addr (cdr form)))))
1206           (symbol
1207            (let ((kind (info :variable :kind form)))
1208              (when (eq kind :alien)
1209                `(%heap-alien-addr ',(info :variable :alien-info form))))))
1210         (error "~S is not a valid L-value." form))))
1211
1212 (/show0 "host-alieneval.lisp end of file")