X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fhost-c-call.lisp;h=7b558afcddda9d050fafc4fb2f97122c63a44e42;hb=adaba39fb52f52487bd1a1b632b735e59045e19d;hp=1976a2f847da2eaa64f0c873d02c4b7748ee52b5;hpb=54b330585ed41edeb93a289f0e59aec67fa9ded9;p=sbcl.git diff --git a/src/code/host-c-call.lisp b/src/code/host-c-call.lisp index 1976a2f..7b558af 100644 --- a/src/code/host-c-call.lisp +++ b/src/code/host-c-call.lisp @@ -13,15 +13,18 @@ (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))) @@ -30,16 +33,34 @@ 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 @@ -49,15 +70,24 @@ ;; 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. @@ -77,45 +107,34 @@ `(%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")