external/cffi.darcs/_darcs/pristine/src/cffi-sbcl.lisp

   1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
   2 ;;;
   3 ;;; cffi-sbcl.lisp --- CFFI-SYS implementation for SBCL.
   4 ;;;
   5 ;;; Copyright (C) 2005-2006, James Bielman  <jamesjb@jamesjb.com>
   6 ;;;
   7 ;;; Permission is hereby granted, free of charge, to any person
   8 ;;; obtaining a copy of this software and associated documentation
   9 ;;; files (the "Software"), to deal in the Software without
  10 ;;; restriction, including without limitation the rights to use, copy,
  11 ;;; modify, merge, publish, distribute, sublicense, and/or sell copies
  12 ;;; of the Software, and to permit persons to whom the Software is
  13 ;;; furnished to do so, subject to the following conditions:
  14 ;;;
  15 ;;; The above copyright notice and this permission notice shall be
  16 ;;; included in all copies or substantial portions of the Software.
  17 ;;;
  18 ;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19 ;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20 ;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21 ;;; NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22 ;;; HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23 ;;; WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24 ;;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25 ;;; DEALINGS IN THE SOFTWARE.
  26 ;;;
  27
  28 ;;;# Administrivia
  29
  30 (defpackage #:cffi-sys
  31   (:use #:common-lisp #:sb-alien #:cffi-utils #:alexandria)
  32   (:export
  33    #:canonicalize-symbol-name-case
  34    #:foreign-pointer
  35    #:pointerp
  36    #:pointer-eq
  37    #:null-pointer
  38    #:null-pointer-p
  39    #:inc-pointer
  40    #:make-pointer
  41    #:pointer-address
  42    #:%foreign-alloc
  43    #:foreign-free
  44    #:with-foreign-pointer
  45    #:%foreign-funcall
  46    #:%foreign-funcall-pointer
  47    #:%foreign-type-alignment
  48    #:%foreign-type-size
  49    #:%load-foreign-library
  50    #:%close-foreign-library
  51    #:native-namestring
  52    #:%mem-ref
  53    #:%mem-set
  54    #:make-shareable-byte-vector
  55    #:with-pointer-to-vector-data
  56    #:%foreign-symbol-pointer
  57    #:%defcallback
  58    #:%callback))
  59
  60 (in-package #:cffi-sys)
  61
  62 ;;;# Mis-features
  63
  64 (eval-when (:compile-toplevel :load-toplevel :execute)
  65   (mapc (lambda (feature) (pushnew feature *features*))
  66         '(cffi-features:flat-namespace)))
  67
  68 ;;;# Symbol Case
  69
  70 (declaim (inline canonicalize-symbol-name-case))
  71 (defun canonicalize-symbol-name-case (name)
  72   (declare (string name))
  73   (string-upcase name))
  74
  75 ;;;# Basic Pointer Operations
  76
  77 (deftype foreign-pointer ()
  78   'sb-sys:system-area-pointer)
  79
  80 (declaim (inline pointerp))
  81 (defun pointerp (ptr)
  82   "Return true if PTR is a foreign pointer."
  83   (sb-sys:system-area-pointer-p ptr))
  84
  85 (declaim (inline pointer-eq))
  86 (defun pointer-eq (ptr1 ptr2)
  87   "Return true if PTR1 and PTR2 point to the same address."
  88   (declare (type system-area-pointer ptr1 ptr2))
  89   (sb-sys:sap= ptr1 ptr2))
  90
  91 (declaim (inline null-pointer))
  92 (defun null-pointer ()
  93   "Construct and return a null pointer."
  94   (sb-sys:int-sap 0))
  95
  96 (declaim (inline null-pointer-p))
  97 (defun null-pointer-p (ptr)
  98   "Return true if PTR is a null pointer."
  99   (declare (type system-area-pointer ptr))
 100   (zerop (sb-sys:sap-int ptr)))
 101
 102 (declaim (inline inc-pointer))
 103 (defun inc-pointer (ptr offset)
 104   "Return a pointer pointing OFFSET bytes past PTR."
 105   (declare (type system-area-pointer ptr)
 106            (type integer offset))
 107   (sb-sys:sap+ ptr offset))
 108
 109 (declaim (inline make-pointer))
 110 (defun make-pointer (address)
 111   "Return a pointer pointing to ADDRESS."
 112   ;; (declare (type (unsigned-byte 32) address))
 113   (sb-sys:int-sap address))
 114
 115 (declaim (inline pointer-address))
 116 (defun pointer-address (ptr)
 117   "Return the address pointed to by PTR."
 118   (declare (type system-area-pointer ptr))
 119   (sb-sys:sap-int ptr))
 120
 121 ;;;# Allocation
 122 ;;;
 123 ;;; Functions and macros for allocating foreign memory on the stack
 124 ;;; and on the heap.  The main CFFI package defines macros that wrap
 125 ;;; FOREIGN-ALLOC and FOREIGN-FREE in UNWIND-PROTECT for the common usage
 126 ;;; when the memory has dynamic extent.
 127
 128 (declaim (inline %foreign-alloc))
 129 (defun %foreign-alloc (size)
 130   "Allocate SIZE bytes on the heap and return a pointer."
 131   ;; (declare (type (unsigned-byte 32) size))
 132   (alien-sap (make-alien (unsigned 8) size)))
 133
 134 (declaim (inline foreign-free))
 135 (defun foreign-free (ptr)
 136   "Free a PTR allocated by FOREIGN-ALLOC."
 137   (declare (type system-area-pointer ptr))
 138   (free-alien (sap-alien ptr (* (unsigned 8)))))
 139
 140 (defmacro with-foreign-pointer ((var size &optional size-var) &body body)
 141   "Bind VAR to SIZE bytes of foreign memory during BODY.  The
 142 pointer in VAR is invalid beyond the dynamic extent of BODY, and
 143 may be stack-allocated if supported by the implementation.  If
 144 SIZE-VAR is supplied, it will be bound to SIZE during BODY."
 145   (unless size-var
 146     (setf size-var (gensym "SIZE")))
 147   ;; If the size is constant we can stack-allocate.
 148   (if (constantp size)
 149       (let ((alien-var (gensym "ALIEN")))
 150         `(with-alien ((,alien-var (array (unsigned 8) ,(eval size))))
 151            (let ((,size-var ,(eval size))
 152                  (,var (alien-sap ,alien-var)))
 153              (declare (ignorable ,size-var))
 154              ,@body)))
 155       `(let* ((,size-var ,size)
 156               (,var (%foreign-alloc ,size-var)))
 157          (unwind-protect
 158               (progn ,@body)
 159            (foreign-free ,var)))))
 160
 161 ;;;# Shareable Vectors
 162 ;;;
 163 ;;; This interface is very experimental.  WITH-POINTER-TO-VECTOR-DATA
 164 ;;; should be defined to perform a copy-in/copy-out if the Lisp
 165 ;;; implementation can't do this.
 166
 167 (declaim (inline make-shareable-byte-vector))
 168 (defun make-shareable-byte-vector (size)
 169   "Create a Lisp vector of SIZE bytes can passed to
 170 WITH-POINTER-TO-VECTOR-DATA."
 171   ; (declare (type sb-int:index size))
 172   (make-array size :element-type '(unsigned-byte 8)))
 173
 174 (defmacro with-pointer-to-vector-data ((ptr-var vector) &body body)
 175   "Bind PTR-VAR to a foreign pointer to the data in VECTOR."
 176   (let ((vector-var (gensym "VECTOR")))
 177     `(let ((,vector-var ,vector))
 178        (declare (type (sb-kernel:simple-unboxed-array (*)) ,vector-var))
 179        (sb-sys:with-pinned-objects (,vector-var)
 180          (let ((,ptr-var (sb-sys:vector-sap ,vector-var)))
 181            ,@body)))))
 182
 183 ;;;# Dereferencing
 184
 185 ;;; Define the %MEM-REF and %MEM-SET functions, as well as compiler
 186 ;;; macros that optimize the case where the type keyword is constant
 187 ;;; at compile-time.
 188 (defmacro define-mem-accessors (&body pairs)
 189   `(progn
 190      (defun %mem-ref (ptr type &optional (offset 0))
 191        (ecase type
 192          ,@(loop for (keyword fn) in pairs
 193                  collect `(,keyword (,fn ptr offset)))))
 194      (defun %mem-set (value ptr type &optional (offset 0))
 195        (ecase type
 196          ,@(loop for (keyword fn) in pairs
 197                  collect `(,keyword (setf (,fn ptr offset) value)))))
 198      (define-compiler-macro %mem-ref
 199          (&whole form ptr type &optional (offset 0))
 200        (if (constantp type)
 201            (ecase (eval type)
 202              ,@(loop for (keyword fn) in pairs
 203                      collect `(,keyword `(,',fn ,ptr ,offset))))
 204            form))
 205      (define-compiler-macro %mem-set
 206          (&whole form value ptr type &optional (offset 0))
 207        (if (constantp type)
 208            (once-only (value)
 209              (ecase (eval type)
 210                ,@(loop for (keyword fn) in pairs
 211                        collect `(,keyword `(setf (,',fn ,ptr ,offset)
 212                                                  ,value)))))
 213            form))))
 214
 215 (define-mem-accessors
 216   (:char sb-sys:signed-sap-ref-8)
 217   (:unsigned-char sb-sys:sap-ref-8)
 218   (:short sb-sys:signed-sap-ref-16)
 219   (:unsigned-short sb-sys:sap-ref-16)
 220   (:int sb-sys:signed-sap-ref-32)
 221   (:unsigned-int sb-sys:sap-ref-32)
 222   (:long sb-sys:signed-sap-ref-word)
 223   (:unsigned-long sb-sys:sap-ref-word)
 224   (:long-long sb-sys:signed-sap-ref-64)
 225   (:unsigned-long-long sb-sys:sap-ref-64)
 226   (:float sb-sys:sap-ref-single)
 227   (:double sb-sys:sap-ref-double)
 228   (:pointer sb-sys:sap-ref-sap))
 229
 230 ;;;# Calling Foreign Functions
 231
 232 (defun convert-foreign-type (type-keyword)
 233   "Convert a CFFI type keyword to an SB-ALIEN type."
 234   (ecase type-keyword
 235     (:char               'char)
 236     (:unsigned-char      'unsigned-char)
 237     (:short              'short)
 238     (:unsigned-short     'unsigned-short)
 239     (:int                'int)
 240     (:unsigned-int       'unsigned-int)
 241     (:long               'long)
 242     (:unsigned-long      'unsigned-long)
 243     (:long-long          'long-long)
 244     (:unsigned-long-long 'unsigned-long-long)
 245     (:float              'single-float)
 246     (:double             'double-float)
 247     (:pointer            'system-area-pointer)
 248     (:void               'void)))
 249
 250 (defun %foreign-type-size (type-keyword)
 251   "Return the size in bytes of a foreign type."
 252   (/ (sb-alien-internals:alien-type-bits
 253       (sb-alien-internals:parse-alien-type
 254        (convert-foreign-type type-keyword) nil)) 8))
 255
 256 (defun %foreign-type-alignment (type-keyword)
 257   "Return the alignment in bytes of a foreign type."
 258   #+(and darwin ppc (not ppc64))
 259   (case type-keyword
 260     ((:double :long-long :unsigned-long-long)
 261      (return-from %foreign-type-alignment 8)))
 262   ;; No override necessary for other types...
 263   (/ (sb-alien-internals:alien-type-alignment
 264       (sb-alien-internals:parse-alien-type
 265        (convert-foreign-type type-keyword) nil)) 8))
 266
 267 (defun foreign-funcall-type-and-args (args)
 268   "Return an SB-ALIEN function type for ARGS."
 269   (let ((return-type 'void))
 270     (loop for (type arg) on args by #'cddr
 271           if arg collect (convert-foreign-type type) into types
 272           and collect arg into fargs
 273           else do (setf return-type (convert-foreign-type type))
 274           finally (return (values types fargs return-type)))))
 275
 276 (defmacro %%foreign-funcall (name types fargs rettype)
 277   "Internal guts of %FOREIGN-FUNCALL."
 278   `(alien-funcall
 279     (extern-alien ,name (function ,rettype ,@types))
 280     ,@fargs))
 281
 282 (defmacro %foreign-funcall (name args &key library calling-convention)
 283   "Perform a foreign function call, document it more later."
 284   (declare (ignore library calling-convention))
 285   (multiple-value-bind (types fargs rettype)
 286       (foreign-funcall-type-and-args args)
 287     `(%%foreign-funcall ,name ,types ,fargs ,rettype)))
 288
 289 (defmacro %foreign-funcall-pointer (ptr args &key calling-convention)
 290   "Funcall a pointer to a foreign function."
 291   (declare (ignore calling-convention))
 292   (multiple-value-bind (types fargs rettype)
 293       (foreign-funcall-type-and-args args)
 294     (with-unique-names (function)
 295       `(with-alien ((,function (* (function ,rettype ,@types)) ,ptr))
 296          (alien-funcall ,function ,@fargs)))))
 297
 298 ;;;# Callbacks
 299
 300 ;;; The *CALLBACKS* hash table contains a direct mapping of CFFI
 301 ;;; callback names to SYSTEM-AREA-POINTERs obtained by ALIEN-LAMBDA.
 302 ;;; SBCL will maintain the addresses of the callbacks across saved
 303 ;;; images, so it is safe to store the pointers directly.
 304 (defvar *callbacks* (make-hash-table))
 305
 306 (defmacro %defcallback (name rettype arg-names arg-types body
 307                         &key calling-convention)
 308   (declare (ignore calling-convention))
 309   `(setf (gethash ',name *callbacks*)
 310          (alien-sap
 311           (sb-alien::alien-lambda ,(convert-foreign-type rettype)
 312               ,(mapcar (lambda (sym type)
 313                          (list sym (convert-foreign-type type)))
 314                        arg-names arg-types)
 315             ,body))))
 316
 317 (defun %callback (name)
 318   (or (gethash name *callbacks*)
 319       (error "Undefined callback: ~S" name)))
 320
 321 ;;;# Loading and Closing Foreign Libraries
 322
 323 (declaim (inline %load-foreign-library))
 324 (defun %load-foreign-library (name path)
 325   "Load a foreign library."
 326   (declare (ignore name))
 327   (load-shared-object path))
 328
 329 (defun %close-foreign-library (handle)
 330   "Closes a foreign library."
 331   (sb-alien::dlclose-or-lose
 332    (find (sb-ext:native-namestring handle) sb-alien::*shared-objects*
 333          :key #'sb-alien::shared-object-file
 334          :test #'string=)))
 335
 336 (defun native-namestring (pathname)
 337   (sb-ext:native-namestring pathname))
 338
 339 ;;;# Foreign Globals
 340
 341 (defun %foreign-symbol-pointer (name library)
 342   "Returns a pointer to a foreign symbol NAME."
 343   (declare (ignore library))
 344   (when-let (address (sb-sys:find-foreign-symbol-address name))
 345     (sb-sys:int-sap address)))