;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10; Package: UFFI -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          strings.lisp
;;;; Purpose:       UFFI source to handle strings, cstring and foreigns
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  Feb 2002
;;;;
;;;; $Id$
;;;;
;;;; This file, part of UFFI, is Copyright (c) 2002-2010 by Kevin M. Rosenberg
;;;; *************************************************************************

(in-package #:uffi)


(def-pointer-var +null-cstring-pointer+
    #+(or cmu sbcl scl) nil
    #+allegro 0
    #+lispworks (fli:make-pointer :address 0 :type '(:unsigned :char))
    #+(or openmcl digitool) (ccl:%null-ptr)
)

(defmacro convert-from-cstring (obj)
  "Converts a string from a c-call. Same as convert-from-foreign-string, except
that LW/CMU automatically converts strings from c-calls."
  #+(or cmu sbcl lispworks scl) obj
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (zerop ,stored)
           nil
           (values (excl:native-to-string ,stored)))))
  #+(or openmcl digitool)
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (ccl:%null-ptr-p ,stored)
           nil
         (values (ccl:%get-cstring ,stored)))))
  )

(defmacro convert-to-cstring (obj)
  #+(or cmu sbcl scl lispworks) obj
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (null ,stored)
           0
           (values (excl:string-to-native ,stored)))))
  #+(or openmcl digitool)
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (null ,stored)
           +null-cstring-pointer+
           (let ((ptr (new-ptr (1+ (length ,stored)))))
             (ccl::%put-cstring ptr ,stored)
             ptr))))
  )

(defmacro free-cstring (obj)
  #+(or cmu sbcl scl lispworks) (declare (ignore obj))
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (unless (zerop ,stored)
         (ff:free-fobject ,stored))))
  #+(or openmcl digitool)
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (unless (ccl:%null-ptr-p ,stored)
         (dispose-ptr ,stored))))
  )

(defmacro with-cstring ((cstring lisp-string) &body body)
  #+(or cmu sbcl scl lispworks)
  `(let ((,cstring ,lisp-string)) ,@body)
  #+allegro
  (let ((acl-native (gensym))
        (stored-lisp-string (gensym)))
    `(let ((,stored-lisp-string ,lisp-string))
       (excl:with-native-string (,acl-native ,stored-lisp-string)
         (let ((,cstring (if ,stored-lisp-string ,acl-native 0)))
           ,@body))))
  #+(or openmcl digitool)
  (let ((stored-lisp-string (gensym)))
    `(let ((,stored-lisp-string ,lisp-string))
       (if (stringp ,stored-lisp-string)
           (ccl:with-cstrs ((,cstring ,stored-lisp-string))
             ,@body)
           (let ((,cstring +null-cstring-pointer+))
             ,@body))))
  )

(defmacro with-cstrings (bindings &rest body)
  (if bindings
      `(with-cstring ,(car bindings)
        (with-cstrings ,(cdr bindings)
          ,@body))
      `(progn ,@body)))

;;; Foreign string functions

(defmacro convert-to-foreign-string (obj)
  #+lispworks
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (null ,stored)
           +null-cstring-pointer+
           (fli:convert-to-foreign-string
            ,stored
            :external-format '(:latin-1 :eol-style :lf)))))
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (null ,stored)
           0
           (values (excl:string-to-native ,stored)))))
  #+(or cmu scl)
  (let ((size (gensym))
        (storage (gensym))
        (stored-obj (gensym))
        (i (gensym)))
    `(let ((,stored-obj ,obj))
       (etypecase ,stored-obj
         (null
          (alien:sap-alien (system:int-sap 0) (* (alien:unsigned 8))))
         (string
          (let* ((,size (length ,stored-obj))
                 (,storage (alien:make-alien (alien:unsigned 8) (1+ ,size))))
            (setq ,storage (alien:cast ,storage (* (alien:unsigned 8))))
            (locally
                (declare (optimize (speed 3) (safety 0)))
              (dotimes (,i ,size)
                (declare (fixnum ,i))
                (setf (alien:deref ,storage ,i)
                      (char-code (char ,stored-obj ,i))))
           (setf (alien:deref ,storage ,size) 0))
         ,storage)))))
  #+sbcl
  (let ((size (gensym))
        (storage (gensym))
        (stored-obj (gensym))
        (i (gensym)))
    `(let ((,stored-obj ,obj))
       (etypecase ,stored-obj
         (null
          (sb-alien:sap-alien (sb-sys:int-sap 0) (* (sb-alien:unsigned 8))))
         (string
          (let* ((,size (length ,stored-obj))
                 (,storage (sb-alien:make-alien (sb-alien:unsigned 8) (1+ ,size))))
            (setq ,storage (sb-alien:cast ,storage (* (sb-alien:unsigned 8))))
            (locally
                (declare (optimize (speed 3) (safety 0)))
              (dotimes (,i ,size)
                (declare (fixnum ,i))
                (setf (sb-alien:deref ,storage ,i)
                      (char-code (char ,stored-obj ,i))))
              (setf (sb-alien:deref ,storage ,size) 0))
            ,storage)))))
  #+(or openmcl digitool)
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (null ,stored-obj)
           +null-cstring-pointer+
           (let ((ptr (new-ptr (1+ (length ,stored-obj)))))
             (ccl::%put-cstring ptr ,stored-obj)
             ptr))))
  )

;; Either length or null-terminated-p must be non-nil
(defmacro convert-from-foreign-string (obj &key
                                           length
                                           (locale :default)
                                           (null-terminated-p t))
  #+allegro
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (zerop ,stored-obj)
           nil
           (if (eq ,locale :none)
               (fast-native-to-string ,stored-obj ,length)
               (values
                (excl:native-to-string
                 ,stored-obj
                 ,@(when length (list :length length))
                 :truncate (not ,null-terminated-p)))))))
  #+lispworks
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (fli:null-pointer-p ,stored-obj)
           nil
           (if (eq ,locale :none)
               (fast-native-to-string ,stored-obj ,length)
               (fli:convert-from-foreign-string
                ,stored-obj
                ,@(when length (list :length length))
                :null-terminated-p ,null-terminated-p
                :external-format '(:latin-1 :eol-style :lf))))))
  #+(or cmu scl)
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (null-pointer-p ,stored-obj)
           nil
           (cmucl-naturalize-cstring (alien:alien-sap ,stored-obj)
                                     :length ,length
                                     :null-terminated-p ,null-terminated-p))))

  #+sbcl
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (null-pointer-p ,stored-obj)
            nil
            (sbcl-naturalize-cstring (sb-alien:alien-sap ,stored-obj)
                                     :length ,length
                                     :null-terminated-p ,null-terminated-p))))
  #+(or openmcl digitool)
  (declare (ignore null-terminated-p))
  #+(or openmcl digitool)
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (ccl:%null-ptr-p ,stored-obj)
           nil
           #+digitool (ccl:%get-cstring
                                      ,stored-obj 0
                                      ,@(if length (list length) nil))
           #+openmcl ,@(if length
                           `((ccl:%str-from-ptr ,stored-obj ,length))
                           `((ccl:%get-cstring ,stored-obj))))))
  )


(defmacro allocate-foreign-string (size &key (unsigned t))
  #+ignore
  (let ((array-def (gensym)))
    `(let ((,array-def (list 'alien:array 'c-call:char ,size)))
       (eval `(alien:cast (alien:make-alien ,,array-def)
                          ,(if ,unsigned
                               '(* (alien:unsigned 8))
                             '(* (alien:signed 8)))))))

  #+(or cmu scl)
  `(alien:make-alien ,(if unsigned
                             '(alien:unsigned 8)
                             '(alien:signed 8))
    ,size)

  #+sbcl
  `(sb-alien:make-alien ,(if unsigned
                             '(sb-alien:unsigned 8)
                             '(sb-alien:signed 8))
    ,size)

  #+lispworks
  `(fli:allocate-foreign-object :type
                                ,(if unsigned
                                     ''(:unsigned :char)
                                   :char)
                                :nelems ,size)
  #+allegro
  (declare (ignore unsigned))
  #+allegro
  `(ff:allocate-fobject :char :c ,size)
  #+(or openmcl digitool)
  (declare (ignore unsigned))
  #+(or openmcl digitool)
  `(new-ptr ,size)
  )

(defun foreign-string-length (foreign-string)
  #+allegro `(ff:foreign-strlen ,foreign-string)
  #-allegro
  `(loop with size = 0
    until (char= (deref-array ,foreign-string '(:array :unsigned-char) size) #\Null)
    do (incf size)
    finally return size))


(defmacro with-foreign-string ((foreign-string lisp-string) &body body)
  (let ((result (gensym)))
    `(let* ((,foreign-string (convert-to-foreign-string ,lisp-string))
            (,result (progn ,@body)))
      (declare (dynamic-extent ,foreign-string))
      (free-foreign-object ,foreign-string)
      ,result)))

(defmacro with-foreign-strings (bindings &body body)
  `(with-foreign-string ,(car bindings)
    ,@(if (cdr bindings)
          `((with-foreign-strings ,(cdr bindings) ,@body))
          body)))

;; Modified from CMUCL's source to handle non-null terminated strings
#+cmu
(defun cmucl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type system:system-area-pointer sap))
  (locally
      (declare (optimize (speed 3) (safety 0)))
    (let ((null-terminated-length
           (when null-terminated-p
             (loop
                 for offset of-type fixnum upfrom 0
                 until (zerop (system:sap-ref-8 sap offset))
                 finally (return offset)))))
      (if length
          (if (and null-terminated-length
                   (> (the fixnum length) (the fixnum null-terminated-length)))
              (setq length null-terminated-length))
        (setq length null-terminated-length)))
    (let ((result (make-string length)))
      (kernel:copy-from-system-area sap 0
                                    result (* vm:vector-data-offset
                                              vm:word-bits)
                                    (* length vm:byte-bits))
      result)))

#+scl
;; kernel:copy-from-system-area doesn't work like it does on CMUCL or SBCL,
;; so have to iteratively copy from sap
(defun cmucl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type system:system-area-pointer sap))
  (locally
      (declare (optimize (speed 3) (safety 0)))
    (let ((null-terminated-length
           (when null-terminated-p
             (loop
                 for offset of-type fixnum upfrom 0
                 until (zerop (system:sap-ref-8 sap offset))
                 finally (return offset)))))
      (if length
          (if (and null-terminated-length
                   (> (the fixnum length) (the fixnum null-terminated-length)))
              (setq length null-terminated-length))
        (setq length null-terminated-length)))
    (let ((result (make-string length)))
      (dotimes (i length)
        (declare (type fixnum i))
        (setf (char result i) (code-char (system:sap-ref-8 sap i))))
      result)))

#+(and sbcl (not sb-unicode))
(defun sbcl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type sb-sys:system-area-pointer sap)
           (type (or null fixnum) length))
  (locally
   (declare (optimize (speed 3) (safety 0)))
   (let ((null-terminated-length
          (when null-terminated-p
            (loop
             for offset of-type fixnum upfrom 0
             until (zerop (sb-sys:sap-ref-8 sap offset))
             finally (return offset)))))
     (if length
         (if (and null-terminated-length
                  (> (the fixnum length) (the fixnum null-terminated-length)))
             (setq length null-terminated-length))
       (setq length null-terminated-length)))
   (let ((result (make-string length)))
       (funcall *system-copy-fn* sap 0 result +system-copy-offset+
                (* length +system-copy-multiplier+))
       result)))

#+(and sbcl sb-unicode)
(defun sbcl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type sb-sys:system-area-pointer sap)
           (type (or null fixnum) length))
  (locally
   (declare (optimize (speed 3) (safety 0)))
   (cond
    (null-terminated-p
     (let ((casted (sb-alien:cast (sb-alien:sap-alien sap (* char))
                                  #+sb-unicode sb-alien:utf8-string
                                  #-sb-unicode sb-alien:c-string)))
       (if length
           (copy-seq (subseq casted 0 length))
         (copy-seq casted))))
    (t
     (let ((result (make-string length)))
       ;; this will not work in sb-unicode
       (funcall *system-copy-fn* sap 0 result +system-copy-offset+
                (* length +system-copy-multiplier+))
       result)))))


(eval-when (:compile-toplevel :load-toplevel :execute)
   (def-function "strlen"
     ((str (* :unsigned-char)))
     :returning :unsigned-int))

(def-type char-ptr-def (* :unsigned-char))

#+(or (and allegro (not ics)) (and lispworks (not lispworks5) (not lispworks6)))
(defun fast-native-to-string (s len)
  (declare (optimize (speed 3) (space 0) (safety 0) (compilation-speed 0))
           (type char-ptr-def s))
  (let* ((len (or len (strlen s)))
         (str (make-string len)))
    (declare (fixnum len)
             (type (simple-array #+lispworks base-char
                                 #-lispworks (signed-byte 8) (*)) str))
    (dotimes (i len str)
      (setf (aref str i)
        (uffi:deref-array s '(:array :char) i)))))

#+(or (and allegro ics) lispworks5 lispworks6)
(defun fast-native-to-string (s len)
  (declare (optimize (speed 3) (space 0) (safety 0) (compilation-speed 0))
           (type char-ptr-def s))
  (let* ((len (or len (strlen s)))
         (str (make-string len)))
      (dotimes (i len str)
        (setf (schar str i) (code-char (uffi:deref-array s '(:array :unsigned-byte) i))))))