src/utils.lisp

   1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*-
   2 ;;;
   3 ;;; utils.lisp --- Various utilities.
   4 ;;;
   5 ;;; Copyright (C) 2005-2008, Luis Oliveira  <loliveira(@)common-lisp.net>
   6 ;;;
   7 ;;; Permission is hereby granted, free of charge, to any person
   8 ;;; obtaining a copy of this software and associated documentation
   9 ;;; files (the "Software"), to deal in the Software without
  10 ;;; restriction, including without limitation the rights to use, copy,
  11 ;;; modify, merge, publish, distribute, sublicense, and/or sell copies
  12 ;;; of the Software, and to permit persons to whom the Software is
  13 ;;; furnished to do so, subject to the following conditions:
  14 ;;;
  15 ;;; The above copyright notice and this permission notice shall be
  16 ;;; included in all copies or substantial portions of the Software.
  17 ;;;
  18 ;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19 ;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20 ;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21 ;;; NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  22 ;;; HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  23 ;;; WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24 ;;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25 ;;; DEALINGS IN THE SOFTWARE.
  26 ;;;
  27
  28 (in-package #:cffi)
  29
  30 (defmacro discard-docstring (body-var)
  31   "Discards the first element of the list in body-var if it's a
  32 string."
  33   `(when (stringp (car ,body-var))
  34      (pop ,body-var)))
  35
  36 (defun single-bit-p (integer)
  37   "Answer whether INTEGER, which must be an integer, is a single
  38 set twos-complement bit."
  39   (if (<= integer 0)
  40       nil                            ; infinite set bits for negatives
  41       (loop until (logbitp 0 integer)
  42             do (setf integer (ash integer -1))
  43             finally (return (zerop (ash integer -1))))))
  44
  45 ;;; This function is here because it needs to be defined early. It's
  46 ;;; used by DEFINE-PARSE-METHOD and DEFCTYPE to warn users when
  47 ;;; they're defining types whose names belongs to the KEYWORD or CL
  48 ;;; packages.  CFFI itself gets to use keywords without a warning.
  49 (defun warn-if-kw-or-belongs-to-cl (name)
  50   (let ((package (symbol-package name)))
  51     (when (and (not (eq *package* (find-package '#:cffi)))
  52                (member package '(#:common-lisp #:keyword)
  53                        :key #'find-package))
  54       (warn "Defining a foreign type named ~S.  This symbol belongs to the ~A ~
  55              package and that may interfere with other code using CFFI."
  56             name (package-name package)))))
  57
  58 (define-condition obsolete-argument-warning (style-warning)
  59   ((old-arg :initarg :old-arg :reader old-arg)
  60    (new-arg :initarg :new-arg :reader new-arg))
  61   (:report (lambda (c s)
  62              (format s "Keyword ~S is obsolete, please use ~S"
  63                      (old-arg c) (new-arg c)))))
  64
  65 (defun warn-obsolete-argument (old-arg new-arg)
  66   (warn 'obsolete-argument-warning
  67         :old-arg old-arg :new-arg new-arg))
  68
  69 (defun split-if (test seq &optional (dir :before))
  70   (remove-if #'(lambda (x) (equal x (subseq seq 0 0)))
  71              (loop for start fixnum = 0
  72                      then (if (eq dir :before)
  73                               stop
  74                               (the fixnum (1+ (the fixnum stop))))
  75                    while (< start (length seq))
  76                    for stop = (position-if test seq
  77                                            :start (if (eq dir :elide)
  78                                                       start
  79                                                       (the fixnum (1+ start))))
  80                    collect (subseq seq start
  81                                    (if (and stop (eq dir :after))
  82                                        (the fixnum (1+ (the fixnum stop)))
  83                                        stop))
  84                    while stop)))
  85
  86 (defun quoted-form-p (form)
  87   (and (listp form)
  88        (= 2 (length form))
  89        (eql 'quote (car form))))
  90
  91 (defun constant-form-p (form &optional env)
  92   (let ((form (if (symbolp form)
  93                   (macroexpand form env)
  94                   form)))
  95     (or (quoted-form-p form)
  96         (constantp form env))))
  97
  98 (defun constant-form-value (form &optional env)
  99   (declare (ignorable env))
 100   (cond
 101     ((quoted-form-p form)
 102      (second form))
 103     (t
 104      #+clozure
 105      (ccl::eval-constant form)
 106      #+sbcl
 107      (sb-int:constant-form-value form env)
 108      #-(or clozure sbcl)
 109      (eval form))))