1 ;;;; This software is part of the SBCL system. See the README file for
4 ;;;; This software is derived from the CMU CL system, which was
5 ;;;; written at Carnegie Mellon University and released into the
6 ;;;; public domain. The software is in the public domain and is
7 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
8 ;;;; files for more information.
10 (in-package "SB!ALIEN")
12 (/show0 "host-c-call.lisp 12")
14 (define-alien-type-class (c-string :include pointer :include-args (to))
15 (external-format :default :type keyword)
16 (element-type 'character :type (member character base-char)))
18 (define-alien-type-translator c-string
19 (&key (external-format :default)
20 (element-type 'character))
21 (make-alien-c-string-type
22 :to (parse-alien-type 'char (sb!kernel:make-null-lexenv))
23 :element-type element-type
24 :external-format external-format))
26 (defun c-string-external-format (type)
27 (let ((external-format (alien-c-string-type-external-format type)))
28 (if (eq external-format :default)
29 (default-c-string-external-format)
32 (define-alien-type-method (c-string :unparse) (type)
33 (let* ((external-format (alien-c-string-type-external-format type))
34 (element-type (alien-c-string-type-element-type type))
36 (append (unless (eq :default external-format)
37 (list :external-format external-format))
38 (unless (eq 'character element-type)
39 (list :element-type element-type))) ))
44 (define-alien-type-method (c-string :lisp-rep) (type)
45 (declare (ignore type))
46 '(or simple-string null (alien (* char)) (simple-array (unsigned-byte 8))))
48 (define-alien-type-method (c-string :deport-pin-p) (type)
49 (declare (ignore type))
52 (defun c-string-needs-conversion-p (type)
54 (declare (ignore type))
58 (let ((external-format (sb!impl::get-external-format
59 ;; Can't use C-STRING-EXTERNAL-FORMAT here,
60 ;; since the meaning of :DEFAULT can change
61 ;; when *DEFAULT-C-STRING-EXTERNAL-FORMAT*
63 (alien-c-string-type-external-format type))))
64 (not (and external-format
65 (or (eq (first (sb!impl::ef-names external-format)) :ascii)
66 ;; On non-SB-UNICODE all latin-1 codepoints will fit
67 ;; into a base-char, on SB-UNICODE they won't.
69 (eq (first (sb!impl::ef-names external-format)) :latin-1))))))
71 (define-alien-type-method (c-string :naturalize-gen) (type alien)
72 `(if (zerop (sap-int ,alien))
74 ;; Check whether we need to do a full external-format
75 ;; conversion, or whether we can just do a cheap byte-by-byte
76 ;; copy of the c-string data.
78 ;; On SB-UNICODE we can never do the cheap copy, even if the
79 ;; external format and element-type are suitable, since
80 ;; simple-base-strings may not contain ISO-8859-1 characters.
81 ;; If we need to check for non-ascii data in the input, we
82 ;; might as well go through the usual external-format machinery
83 ;; instead of rewriting another version of it.
85 #!-sb-unicode (c-string-needs-conversion-p type)
86 `(sb!alien::c-string-to-string ,alien
87 (c-string-external-format ,type)
88 (alien-c-string-type-element-type
90 `(%naturalize-c-string ,alien))))
92 (define-alien-type-method (c-string :deport-gen) (type value)
93 (declare (ignore type))
94 ;; This SAP taking is safe as DEPORT callers pin the VALUE when
98 ((alien (* char)) (alien-sap ,value))
99 (vector (vector-sap ,value))))
101 (define-alien-type-method (c-string :deport-alloc-gen) (type value)
104 ((alien (* char)) ,value)
106 ,(if (c-string-needs-conversion-p type)
107 ;; If the alien type is not ascii-compatible (+SB-UNICODE)
108 ;; or latin-1-compatible (-SB-UNICODE), we need to do
109 ;; external format conversion.
110 `(string-to-c-string ,value
111 (c-string-external-format ,type))
112 ;; Otherwise we can just pass it uncopied.
115 (string-to-c-string ,value
116 (c-string-external-format ,type)))))
118 (/show0 "host-c-call.lisp end of file")