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3rdparties/software/cffi_0.21.0/src/enum.lisp (15859 bytes)

 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
 ;;;
 ;;; enum.lisp --- Defining foreign constants as Lisp keywords.
 ;;;
 ;;; Copyright (C) 2005-2006, James Bielman  <jamesjb@jamesjb.com>
 ;;;
 ;;; Permission is hereby granted, free of charge, to any person
 ;;; obtaining a copy of this software and associated documentation
 ;;; files (the "Software"), to deal in the Software without
 ;;; restriction, including without limitation the rights to use, copy,
 ;;; modify, merge, publish, distribute, sublicense, and/or sell copies
 ;;; of the Software, and to permit persons to whom the Software is
 ;;; furnished to do so, subject to the following conditions:
 ;;;
 ;;; The above copyright notice and this permission notice shall be
 ;;; included in all copies or substantial portions of the Software.
 ;;;
 ;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 ;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 ;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 ;;; NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 ;;; HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 ;;; WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 ;;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 ;;; DEALINGS IN THE SOFTWARE.
 ;;;
 
 (in-package #:cffi)
 
 ;; TODO the accessors names are rather inconsistent:
 ;; FOREIGN-ENUM-VALUE           FOREIGN-BITFIELD-VALUE
 ;; FOREIGN-ENUM-KEYWORD         FOREIGN-BITFIELD-SYMBOLS
 ;; FOREIGN-ENUM-KEYWORD-LIST    FOREIGN-BITFIELD-SYMBOL-LIST
 ;; I'd rename them to: FOREIGN-*-KEY(S) and FOREIGN-*-ALL-KEYS -- attila
 
 ;; TODO bitfield is a confusing name, because the C standard calls
 ;; the "int foo : 3" type as a bitfield. Maybe rename to defbitmask?
 ;; -- attila
 
 ;;;# Foreign Constants as Lisp Keywords
 ;;;
 ;;; This module defines the DEFCENUM macro, which provides an
 ;;; interface for defining a type and associating a set of integer
 ;;; constants with keyword symbols for that type.
 ;;;
 ;;; The keywords are automatically translated to the appropriate
 ;;; constant for the type by a type translator when passed as
 ;;; arguments or a return value to a foreign function.
 
 (defclass foreign-enum (named-foreign-type enhanced-foreign-type)
   ((keyword-values
     :initform (error "Must specify KEYWORD-VALUES.")
     :initarg :keyword-values
     :reader keyword-values)
    (value-keywords
     :initform (error "Must specify VALUE-KEYWORDS.")
     :initarg :value-keywords
     :reader value-keywords))
   (:documentation "Describes a foreign enumerated type."))
 
 (deftype enum-key ()
   '(and symbol (not null)))
 
 (defparameter +valid-enum-base-types+ *built-in-integer-types*)
 
 (defun parse-foreign-enum-like (type-name base-type values
                                 &optional field-mode-p)
   (let ((keyword-values (make-hash-table :test 'eq))
         (value-keywords (make-hash-table))
         (field-keywords (list))
         (bit-index->keyword (make-array 0 :adjustable t
                                         :element-type t))
         (default-value (if field-mode-p 1 0))
         (most-extreme-value 0)
         (has-negative-value? nil))
     (dolist (pair values)
       (destructuring-bind (keyword &optional (value default-value valuep))
           (ensure-list pair)
         (check-type keyword enum-key)
         ;;(check-type value integer)
         (when (> (abs value) (abs most-extreme-value))
           (setf most-extreme-value value))
         (when (minusp value)
           (setf has-negative-value? t))
         (if field-mode-p
             (if valuep
                 (when (and (>= value default-value)
                            (single-bit-p value))
                   (setf default-value (ash value 1)))
                 (setf default-value (ash default-value 1)))
             (setf default-value (1+ value)))
         (if (gethash keyword keyword-values)
             (error "A foreign enum cannot contain duplicate keywords: ~S."
                    keyword)
             (setf (gethash keyword keyword-values) value))
         ;; This is completely arbitrary behaviour: we keep the last
         ;; value->keyword mapping. I suppose the opposite would be
         ;; just as good (keeping the first). Returning a list with all
         ;; the keywords might be a solution too? Suggestions
         ;; welcome. --luis
         (setf (gethash value value-keywords) keyword)
         (when (and field-mode-p
                    (single-bit-p value))
           (let ((bit-index (1- (integer-length value))))
             (push keyword field-keywords)
             (when (<= (array-dimension bit-index->keyword 0)
                       bit-index)
               (setf bit-index->keyword
                     (adjust-array bit-index->keyword (1+ bit-index)
                                   :initial-element nil)))
             (setf (aref bit-index->keyword bit-index)
                   keyword)))))
     (if base-type
         (progn
           (setf base-type (canonicalize-foreign-type base-type))
           ;; I guess we don't lose much by not strictly adhering to
           ;; the C standard here, and some libs out in the wild are
           ;; already using e.g. :double.
           #+nil
           (assert (member base-type +valid-enum-base-types+ :test 'eq) ()
                   "Invalid base type ~S for enum type ~S. Must be one of ~S."
                   base-type type-name +valid-enum-base-types+))
         ;; details: https://stackoverflow.com/questions/1122096/what-is-the-underlying-type-of-a-c-enum
         (let ((bits (integer-length most-extreme-value)))
           (setf base-type
                 (let ((most-uint-bits      (load-time-value (* (foreign-type-size :unsigned-int) 8)))
                       (most-ulong-bits     (load-time-value (* (foreign-type-size :unsigned-long) 8)))
                       (most-ulonglong-bits (load-time-value (* (foreign-type-size :unsigned-long-long) 8))))
                   (or (if has-negative-value?
                           (cond
                             ((<= (1+ bits) most-uint-bits)
                              :int)
                             ((<= (1+ bits) most-ulong-bits)
                              :long)
                             ((<= (1+ bits) most-ulonglong-bits)
                              :long-long))
                           (cond
                             ((<= bits most-uint-bits)
                              :unsigned-int)
                             ((<= bits most-ulong-bits)
                              :unsigned-long)
                             ((<= bits most-ulonglong-bits)
                              :unsigned-long-long)))
                       (error "Enum value ~S of enum ~S is too large to store."
                              most-extreme-value type-name))))))
     (values base-type keyword-values value-keywords
             field-keywords (when field-mode-p
                              (alexandria:copy-array
                               bit-index->keyword :adjustable nil
                               :fill-pointer nil)))))
 
 (defun make-foreign-enum (type-name base-type values)
   "Makes a new instance of the foreign-enum class."
   (multiple-value-bind
         (base-type keyword-values value-keywords)
       (parse-foreign-enum-like type-name base-type values)
     (make-instance 'foreign-enum
                    :name type-name
                    :actual-type (parse-type base-type)
                    :keyword-values keyword-values
                    :value-keywords value-keywords)))
 
 (defun %defcenum-like (name-and-options enum-list type-factory)
   (discard-docstring enum-list)
   (destructuring-bind (name &optional base-type)
       (ensure-list name-and-options)
     (let ((type (funcall type-factory name base-type enum-list)))
       `(eval-when (:compile-toplevel :load-toplevel :execute)
          (notice-foreign-type ',name
                               ;; ,type is not enough here, someone needs to
                               ;; define it when we're being loaded from a fasl.
                               (,type-factory ',name ',base-type ',enum-list))
          ,@(remove nil
                    (mapcar (lambda (key)
                              (unless (keywordp key)
                                `(defconstant ,key ,(foreign-enum-value type key))))
                            (foreign-enum-keyword-list type)))))))
 
 (defmacro defcenum (name-and-options &body enum-list)
   "Define an foreign enumerated type."
   (%defcenum-like name-and-options enum-list 'make-foreign-enum))
 
 (defun hash-keys-to-list (ht)
   (loop for k being the hash-keys in ht collect k))
 
 (defun foreign-enum-keyword-list (enum-type)
   "Return a list of KEYWORDS defined in ENUM-TYPE."
   (hash-keys-to-list (keyword-values (ensure-parsed-base-type enum-type))))
 
 ;;; These [four] functions could be good canditates for compiler macros
 ;;; when the value or keyword is constant.  I am not going to bother
 ;;; until someone has a serious performance need to do so though. --jamesjb
 (defun %foreign-enum-value (type keyword &key errorp)
   (check-type keyword enum-key)
   (or (gethash keyword (keyword-values type))
       (when errorp
         (error "~S is not defined as a keyword for enum type ~S."
                keyword type))))
 
 (defun foreign-enum-value (type keyword &key (errorp t))
   "Convert a KEYWORD into an integer according to the enum TYPE."
   (let ((type-obj (ensure-parsed-base-type type)))
     (if (not (typep type-obj 'foreign-enum))
       (error "~S is not a foreign enum type." type)
       (%foreign-enum-value type-obj keyword :errorp errorp))))
 
 (defun %foreign-enum-keyword (type value &key errorp)
   (check-type value integer)
   (or (gethash value (value-keywords type))
       (when errorp
         (error "~S is not defined as a value for enum type ~S."
                value type))))
 
 (defun foreign-enum-keyword (type value &key (errorp t))
   "Convert an integer VALUE into a keyword according to the enum TYPE."
   (let ((type-obj (ensure-parsed-base-type type)))
     (if (not (typep type-obj 'foreign-enum))
         (error "~S is not a foreign enum type." type)
         (%foreign-enum-keyword type-obj value :errorp errorp))))
 
 (defmethod translate-to-foreign (value (type foreign-enum))
   (if (typep value 'enum-key)
       (%foreign-enum-value type value :errorp t)
       value))
 
 (defmethod translate-into-foreign-memory
     (value (type foreign-enum) pointer)
   (setf (mem-aref pointer (unparse-type (actual-type type)))
         (translate-to-foreign value type)))
 
 (defmethod translate-from-foreign (value (type foreign-enum))
   (%foreign-enum-keyword type value :errorp t))
 
 (defmethod expand-to-foreign (value (type foreign-enum))
   (once-only (value)
     `(if (typep ,value 'enum-key)
          (%foreign-enum-value ,type ,value :errorp t)
          ,value)))
 
 ;;; There are two expansions necessary for an enum: first, the enum
 ;;; keyword needs to be translated to an int, and then the int needs
 ;;; to be made indirect.
 (defmethod expand-to-foreign-dyn-indirect (value var body (type foreign-enum))
   (expand-to-foreign-dyn-indirect       ; Make the integer indirect
    (with-unique-names (feint)
      (call-next-method value feint (list feint) type)) ; TRANSLATABLE-FOREIGN-TYPE method
    var
    body
    (actual-type type)))
 
 ;;;# Foreign Bitfields as Lisp keywords
 ;;;
 ;;; DEFBITFIELD is an abstraction similar to the one provided by DEFCENUM.
 ;;; With some changes to DEFCENUM, this could certainly be implemented on
 ;;; top of it.
 
 (defclass foreign-bitfield (foreign-enum)
   ((field-keywords
     :initform (error "Must specify FIELD-KEYWORDS.")
     :initarg :field-keywords
     :reader field-keywords)
    (bit-index->keyword
     :initform (error "Must specify BIT-INDEX->KEYWORD")
     :initarg :bit-index->keyword
     :reader bit-index->keyword))
   (:documentation "Describes a foreign bitfield type."))
 
 (defun make-foreign-bitfield (type-name base-type values)
   "Makes a new instance of the foreign-bitfield class."
   (multiple-value-bind
         (base-type keyword-values value-keywords
                    field-keywords bit-index->keyword)
       (parse-foreign-enum-like type-name base-type values t)
     (make-instance 'foreign-bitfield
                    :name type-name
                    :actual-type (parse-type base-type)
                    :keyword-values keyword-values
                    :value-keywords value-keywords
                    :field-keywords field-keywords
                    :bit-index->keyword bit-index->keyword)))
 
 (defmacro defbitfield (name-and-options &body masks)
   "Define an foreign enumerated type."
   (%defcenum-like name-and-options masks 'make-foreign-bitfield))
 
 (defun foreign-bitfield-symbol-list (bitfield-type)
   "Return a list of SYMBOLS defined in BITFIELD-TYPE."
   (field-keywords (ensure-parsed-base-type bitfield-type)))
 
 (defun %foreign-bitfield-value (type symbols)
   (declare (optimize speed))
   (labels ((process-one (symbol)
              (check-type symbol symbol)
              (or (gethash symbol (keyword-values type))
                  (error "~S is not a valid symbol for bitfield type ~S."
                         symbol type))))
     (declare (dynamic-extent #'process-one))
     (cond
       ((consp symbols)
        (reduce #'logior symbols :key #'process-one))
       ((null symbols)
        0)
       (t
        (process-one symbols)))))
 
 (defun foreign-bitfield-value (type symbols)
   "Convert a list of symbols into an integer according to the TYPE bitfield."
   (let ((type-obj (ensure-parsed-base-type type)))
     (assert (typep type-obj 'foreign-bitfield) ()
             "~S is not a foreign bitfield type." type)
     (%foreign-bitfield-value type-obj symbols)))
 
 (define-compiler-macro foreign-bitfield-value (&whole form type symbols)
   "Optimize for when TYPE and SYMBOLS are constant."
   (declare (notinline foreign-bitfield-value))
   (if (and (constantp type) (constantp symbols))
       (foreign-bitfield-value (eval type) (eval symbols))
       form))
 
 (defun %foreign-bitfield-symbols (type value)
   (check-type value integer)
   (check-type type foreign-bitfield)
   (loop
     :with bit-index->keyword = (bit-index->keyword type)
     :for bit-index :from 0 :below (array-dimension bit-index->keyword 0)
     :for mask = 1 :then (ash mask 1)
     :for key = (aref bit-index->keyword bit-index)
     :when (and key
                (= (logand value mask) mask))
     :collect key))
 
 (defun foreign-bitfield-symbols (type value)
   "Convert an integer VALUE into a list of matching symbols according to
 the bitfield TYPE."
   (let ((type-obj (ensure-parsed-base-type type)))
     (if (not (typep type-obj 'foreign-bitfield))
         (error "~S is not a foreign bitfield type." type)
         (%foreign-bitfield-symbols type-obj value))))
 
 (define-compiler-macro foreign-bitfield-symbols (&whole form type value)
   "Optimize for when TYPE and SYMBOLS are constant."
   (declare (notinline foreign-bitfield-symbols))
   (if (and (constantp type) (constantp value))
       `(quote ,(foreign-bitfield-symbols (eval type) (eval value)))
       form))
 
 (defmethod translate-to-foreign (value (type foreign-bitfield))
   (if (integerp value)
       value
       (%foreign-bitfield-value type (ensure-list value))))
 
 (defmethod translate-from-foreign (value (type foreign-bitfield))
   (%foreign-bitfield-symbols type value))
 
 (defmethod expand-to-foreign (value (type foreign-bitfield))
   (flet ((expander (value type)
            `(if (integerp ,value)
                 ,value
                 (%foreign-bitfield-value ,type (ensure-list ,value)))))
     (if (constantp value)
         (eval (expander value type))
         (expander value type))))
 
 (defmethod expand-from-foreign (value (type foreign-bitfield))
   (flet ((expander (value type)
            `(%foreign-bitfield-symbols ,type ,value)))
     (if (constantp value)
         (eval (expander value type))
         (expander value type))))