(define-alien-type-class (c-string :include pointer :include-args (to))
(external-format :default :type keyword)
- (element-type 'character :type (member character base-char)))
+ (element-type 'character :type (member character base-char))
+ (not-null nil :type boolean))
(define-alien-type-translator c-string
(&key (external-format :default)
- (element-type 'character))
+ (element-type 'character)
+ (not-null nil))
(make-alien-c-string-type
:to (parse-alien-type 'char (sb!kernel:make-null-lexenv))
:element-type element-type
- :external-format external-format))
+ :external-format external-format
+ :not-null not-null))
(defun c-string-external-format (type)
(let ((external-format (alien-c-string-type-external-format type)))
external-format)))
(define-alien-type-method (c-string :unparse) (type)
- (list 'c-string
- :external-format (alien-c-string-type-external-format type)
- :element-type (alien-c-string-type-element-type type)))
+ (let* ((external-format (alien-c-string-type-external-format type))
+ (element-type (alien-c-string-type-element-type type))
+ (not-null (alien-c-string-type-not-null type))
+ (tail
+ (append (unless (eq :default external-format)
+ (list :external-format external-format))
+ (unless (eq 'character element-type)
+ (list :element-type element-type))
+ (when not-null
+ (list :not-null t)))))
+ (if tail
+ (cons 'c-string tail)
+ 'c-string)))
(define-alien-type-method (c-string :lisp-rep) (type)
+ (let ((possibilities '(simple-string (alien (* char)) (simple-array (unsigned-byte 8)))))
+ (if (alien-c-string-type-not-null type)
+ `(or ,@possibilities)
+ `(or null ,@possibilities))))
+
+(define-alien-type-method (c-string :deport-pin-p) (type)
(declare (ignore type))
- '(or simple-string null (alien (* char))))
+ t)
(defun c-string-needs-conversion-p (type)
#+sb-xc-host
+ (declare (ignore type))
+ #+sb-xc-host
t
#-sb-xc-host
(let ((external-format (sb!impl::get-external-format
;; changes.
(alien-c-string-type-external-format type))))
(not (and external-format
- (or (eq (caar external-format) :ascii)
+ (or (eq (first (sb!impl::ef-names external-format)) :ascii)
;; On non-SB-UNICODE all latin-1 codepoints will fit
;; into a base-char, on SB-UNICODE they won't.
#!-sb-unicode
- (eq (caar external-format) :latin-1))))))
+ (eq (first (sb!impl::ef-names external-format)) :latin-1))))))
+
+(declaim (ftype (sfunction (t) nil) null-error))
+(defun null-error (type)
+ (aver (alien-c-string-type-not-null type))
+ (error 'type-error
+ :expected-type `(alien ,(unparse-alien-type type))
+ :datum nil))
(define-alien-type-method (c-string :naturalize-gen) (type alien)
`(if (zerop (sap-int ,alien))
- nil
+ ,(if (alien-c-string-type-not-null type)
+ `(null-error ',type)
+ nil)
;; Check whether we need to do a full external-format
;; conversion, or whether we can just do a cheap byte-by-byte
;; copy of the c-string data.
`(%naturalize-c-string ,alien))))
(define-alien-type-method (c-string :deport-gen) (type value)
+ ;; This SAP taking is safe as DEPORT callers pin the VALUE when
+ ;; necessary.
`(etypecase ,value
- (null (int-sap 0))
+ (null
+ ,(if (alien-c-string-type-not-null type)
+ `(null-error ',type)
+ `(int-sap 0)))
((alien (* char)) (alien-sap ,value))
- ;; FIXME: GC safety alert! These SAPs are not safe, since the
- ;; Lisp string can move. This is not hard to arrange, for example
- ;; the following will fail very quickly on a SB-UNICODE build:
- ;;
- ;; (setf (bytes-consed-between-gcs) 4096)
- ;; (define-alien-routine "strcmp" int (s1 c-string) (s2 c-string))
- ;;
- ;; (loop
- ;; (let ((string "hello, world"))
- ;; (assert (zerop (strcmp string string)))))
- ;;
- ;; (This will appear to work on post-0.9.8.19 GENCGC, since
- ;; the GC no longer zeroes memory immediately after releasing
- ;; it after a minor GC. Either enabling the READ_PROTECT_FREE_PAGES
- ;; #define in gencgc.c or modifying the example so that a major
- ;; GC will occasionally be triggered would unmask the bug).
- ;;
- ;; The pure VECTOR-SAP branch for the SIMPLE-BASE-STRING case
- ;; will generally be very hard to trigger on GENCGC (even when
- ;; threaded) thanks to GC conservativeness. It's mostly a problem
- ;; on cheneygc. -- JES, 2006-01-13
+ (vector (vector-sap ,value))))
+
+(define-alien-type-method (c-string :deport-alloc-gen) (type value)
+ `(etypecase ,value
+ (null
+ ,(if (alien-c-string-type-not-null type)
+ `(null-error ',type)
+ nil))
+ ((alien (* char)) ,value)
(simple-base-string
,(if (c-string-needs-conversion-p type)
;; If the alien type is not ascii-compatible (+SB-UNICODE)
;; or latin-1-compatible (-SB-UNICODE), we need to do
;; external format conversion.
- `(vector-sap (string-to-c-string ,value
- (c-string-external-format ,type)))
+ `(string-to-c-string ,value
+ (c-string-external-format ,type))
;; Otherwise we can just pass it uncopied.
- `(vector-sap ,value)))
- ;; This case, on the other hand, will cause trouble on GENCGC, since
- ;; we're taking the SAP of a immediately discarded temporary -> the
- ;; conservativeness doesn't protect us.
- ;; -- JES, 2006-01-13
+ value))
(simple-string
- (vector-sap (string-to-c-string ,value
- (c-string-external-format ,type))))))
+ (string-to-c-string ,value
+ (c-string-external-format ,type)))))
(/show0 "host-c-call.lisp end of file")
projects / sbcl.git / blobdiff