(make-heap-alien-info :type type
:sap-form `(foreign-symbol-sap ',alien-name t)))))
+(defun alien-value (symbol)
+ #!+sb-doc
+ "Returns the value of the alien variable bound to SYMBOL. Signals an
+error if SYMBOL is not bound to an alien variable, or if the alien
+variable is undefined."
+ (%heap-alien (or (info :variable :alien-info symbol)
+ (error 'unbound-variable :name symbol))))
+
(defmacro extern-alien (name type &environment env)
#!+sb-doc
"Access the alien variable named NAME, assuming it is of type TYPE. This
,@body))))
(:local
(/show0 ":LOCAL case")
- (let* ((var (gensym))
- (initval (if initial-value (gensym)))
+ (let* ((var (sb!xc:gensym "VAR"))
+ (initval (if initial-value (sb!xc:gensym "INITVAL")))
(info (make-local-alien-info :type alien-type))
(inner-body
`((note-local-alien-type ',info ,var)
(defmacro make-alien (type &optional size &environment env)
#!+sb-doc
- "Allocate an alien of type TYPE and return an alien pointer to it. If SIZE
-is supplied, how it is interpreted depends on TYPE. If TYPE is an array type,
-SIZE is used as the first dimension for the allocated array. If TYPE is not an
-array, then SIZE is the number of elements to allocate. The memory is
-allocated using ``malloc'', so it can be passed to foreign functions which use
-``free''."
+ "Allocate an alien of type TYPE in foreign heap, and return an alien
+pointer to it. The allocated memory is not initialized, and may
+contain garbage. The memory is allocated using malloc(3), so it can be
+passed to foreign functions which use free(3), or released using
+FREE-ALIEN.
+
+For alien stack allocation, see macro WITH-ALIEN.
+
+The TYPE argument is not evaluated. If SIZE is supplied, how it is
+interpreted depends on TYPE:
+
+ * When TYPE is a foreign array type, an array of that type is
+ allocated, and a pointer to it is returned. Note that you
+ must use DEREF to first access the arrey through the pointer.
+
+ If supplied, SIZE is used as the first dimension for the array.
+
+ * When TYPE is any other foreign type, then an object for that
+ type is allocated, and a pointer to it is returned. So
+ (make-alien int) returns a (* int).
+
+ If SIZE is specified, then a block of that many objects is
+ allocated, with the result pointing to the first one.
+
+Examples:
+
+ (defvar *foo* (make-alien (array char 10)))
+ (type-of *foo*) ; => (alien (* (array (signed 8) 10)))
+ (setf (deref (deref foo) 0) 10) ; => 10
+
+ (make-alien char 12) ; => (alien (* (signed 8)))
+"
(let ((alien-type (if (alien-type-p type)
type
(parse-alien-type type env))))
;; undesirable, in most uses of MAKE-ALIEN the %SAP-ALIEN
;; cannot be optimized away.
`(locally (declare (muffle-conditions compiler-note))
- (%sap-alien (%make-alien (* ,(align-offset bits alignment)
- ,size-expr))
+ ;; FIXME: Do we really need the ASH/+7 here after ALIGN-OFFSET?
+ (%sap-alien (%make-alien (* ,(ash (+ 7 (align-offset bits alignment)) -3)
+ (the index ,size-expr)))
',(make-alien-pointer-type :to alien-type)))))))
+(defun malloc-error (bytes errno)
+ (error 'simple-storage-condition
+ :format-control "~A: malloc() of ~S bytes failed."
+ :format-arguments (list (strerror errno) bytes)))
+
;;; Allocate a block of memory at least BITS bits long and return a
;;; system area pointer to it.
#!-sb-fluid (declaim (inline %make-alien))
-(defun %make-alien (bits)
- (declare (type index bits))
- (alien-funcall (extern-alien "malloc"
- (function system-area-pointer unsigned))
- (ash (the index (+ bits 7)) -3)))
+(defun %make-alien (bytes)
+ (declare (type index bytes)
+ (optimize (sb!c:alien-funcall-saves-fp-and-pc 0)))
+ (let ((sap (alien-funcall (extern-alien "malloc"
+ (function system-area-pointer size-t))
+ bytes)))
+ (if (and (not (eql 0 bytes)) (eql 0 (sap-int sap)))
+ (malloc-error bytes (get-errno))
+ sap)))
#!-sb-fluid (declaim (inline free-alien))
(defun free-alien (alien)
#!+sb-doc
- "Dispose of the storage pointed to by ALIEN. ALIEN must have been allocated
- by MAKE-ALIEN or malloc(3)."
+ "Dispose of the storage pointed to by ALIEN. The ALIEN must have been
+allocated by MAKE-ALIEN, MAKE-ALIEN-STRING or malloc(3)."
(alien-funcall (extern-alien "free" (function (values) system-area-pointer))
(alien-sap alien))
nil)
+
+(declaim (type (sfunction * system-area-pointer) %make-alien-string))
+(defun %make-alien-string (string &key (start 0) end
+ (external-format :default)
+ (null-terminate t))
+ ;; FIXME: This is slow. We want a function to get the length of the
+ ;; encoded string so we can allocate the foreign memory first and
+ ;; encode directly there.
+ (let* ((octets (string-to-octets string
+ :start start :end end
+ :external-format external-format
+ :null-terminate null-terminate))
+ (count (length octets))
+ (buf (%make-alien count)))
+ (sb!kernel:copy-ub8-to-system-area octets 0 buf 0 count)
+ buf))
+
+(defun make-alien-string (string &rest rest
+ &key (start 0) end
+ (external-format :default)
+ (null-terminate t))
+ "Copy part of STRING delimited by START and END into freshly
+allocated foreign memory, freeable using free(3) or FREE-ALIEN.
+Returns the allocated string as a (* CHAR) alien, and the number of
+bytes allocated as secondary value.
+
+The string is encoded using EXTERNAL-FORMAT. If NULL-TERMINATE is
+true (the default), the alien string is terminated by an additional
+null byte.
+"
+ (declare (ignore start end external-format null-terminate))
+ (multiple-value-bind (sap bytes)
+ (apply #'%make-alien-string string rest)
+ (values (%sap-alien sap (parse-alien-type '(* char) nil))
+ bytes)))
+
+(define-compiler-macro make-alien-string (&rest args)
+ `(multiple-value-bind (sap bytes) (%make-alien-string ,@args)
+ (values (%sap-alien sap ',(parse-alien-type '(* char) nil))
+ bytes)))
\f
;;;; the SLOT operator
(let ((stub (alien-fun-type-stub type)))
(unless stub
(setf stub
- (let ((fun (gensym))
+ (let ((fun (sb!xc:gensym "FUN"))
(parms (make-gensym-list (length args))))
(compile nil
`(lambda (,fun ,@parms)
((,lisp-name (function ,result-type ,@(arg-types))
:extern ,alien-name)
,@(alien-vars))
- #-nil
- (values (alien-funcall ,lisp-name ,@(alien-args))
- ,@(results))
- #+nil
- (if (alien-values-type-p result-type)
- ;; FIXME: RESULT-TYPE is a type specifier, so it
- ;; cannot be of type ALIEN-VALUES-TYPE. Also note,
- ;; that if RESULT-TYPE is VOID, then this code
- ;; disagrees with the computation of the return type
- ;; and with all usages of this macro. -- APD,
- ;; 2002-03-02
- (let ((temps (make-gensym-list
- (length
- (alien-values-type-values result-type)))))
- `(multiple-value-bind ,temps
- (alien-funcall ,lisp-name ,@(alien-args))
- (values ,@temps ,@(results))))
- (values (alien-funcall ,lisp-name ,@(alien-args))
- ,@(results)))))))))
+ ,@(if (eq 'void result-type)
+ `((alien-funcall ,lisp-name ,@(alien-args))
+ (values nil ,@(results)))
+ `((values (alien-funcall ,lisp-name ,@(alien-args))
+ ,@(results))))))))))
\f
(defun alien-typep (object type)
#!+sb-doc
(and (alien-value-p object)
(alien-subtype-p (alien-value-type object) type)))))
+(defun alien-value-typep (object type)
+ (when (alien-value-p object)
+ (alien-subtype-p (alien-value-type object) type)))
+
;;;; ALIEN CALLBACKS
;;;;
;;;; See "Foreign Linkage / Callbacks" in the SBCL Internals manual.
:local ,(alien-callback-accessor-form
spec 'args-sap offset))
do (incf offset (alien-callback-argument-bytes spec env)))
- ,(flet ((store (spec)
+ ,(flet ((store (spec real-type)
(if spec
`(setf (deref (sap-alien res-sap (* ,spec)))
- (funcall function ,@arguments))
+ ,(if real-type
+ `(the ,real-type
+ (funcall function ,@arguments))
+ `(funcall function ,@arguments)))
`(funcall function ,@arguments))))
(cond ((alien-void-type-p result-type)
- (store nil))
+ (store nil nil))
((alien-integer-type-p result-type)
+ ;; Integer types should be padded out to a full
+ ;; register width, to comply with most ABI calling
+ ;; conventions, but should be typechecked on the
+ ;; declared type width, hence the following:
(if (alien-integer-type-signed result-type)
(store `(signed
- ,(alien-type-word-aligned-bits result-type)))
+ ,(alien-type-word-aligned-bits result-type))
+ `(signed-byte ,(alien-type-bits result-type)))
(store
`(unsigned
- ,(alien-type-word-aligned-bits result-type)))))
+ ,(alien-type-word-aligned-bits result-type))
+ `(unsigned-byte ,(alien-type-bits result-type)))))
(t
- (store (unparse-alien-type result-type)))))))
+ (store (unparse-alien-type result-type) nil))))))
(values))))
(defun invalid-alien-callback (&rest arguments)
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