lisp/emacs-lisp/check-declare.el

   1 ;;; check-declare.el --- Check declare-function statements
   2
   3 ;; Copyright (C) 2007-2012 Free Software Foundation, Inc.
   4
   5 ;; Author: Glenn Morris <rgm@gnu.org>
   6 ;; Keywords: lisp, tools, maint
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; The byte-compiler often warns about undefined functions that you
  26 ;; know will actually be defined when it matters.  The `declare-function'
  27 ;; statement allows you to suppress these warnings.  This package
  28 ;; checks that all such statements in a file or directory are accurate.
  29 ;; The entry points are `check-declare-file' and `check-declare-directory'.
  30
  31 ;; For more information, see Info node `(elisp)Declaring Functions'.
  32
  33 ;;; TODO:
  34
  35 ;; 1. Warn about functions marked as obsolete, eg
  36 ;; password-read-and-add in smime.el.
  37 ;; 2. defmethod, defclass argument checking.
  38 ;; 3. defclass also defines -p and -child-p.
  39
  40 ;;; Code:
  41
  42 (defconst check-declare-warning-buffer "*Check Declarations Warnings*"
  43   "Name of buffer used to display any `check-declare' warnings.")
  44
  45 (defun check-declare-locate (file basefile)
  46   "Return the full path of FILE.
  47 Expands files with a \".c\" or \".m\" extension relative to the Emacs
  48 \"src/\" directory.  Otherwise, `locate-library' searches for FILE.
  49 If that fails, expands FILE relative to BASEFILE's directory part.
  50 The returned file might not exist.  If FILE has an \"ext:\" prefix, so does
  51 the result."
  52   (let ((ext (string-match "^ext:" file))
  53         tfile)
  54     (if ext
  55         (setq file (substring file 4)))
  56     (setq file
  57           (if (member (file-name-extension file) '("c" "m"))
  58               (expand-file-name file (expand-file-name "src" source-directory))
  59             (if (setq tfile (locate-library file))
  60                 (progn
  61                   (setq tfile
  62                         (replace-regexp-in-string "\\.elc\\'" ".el" tfile))
  63                   (if (and (not (file-exists-p tfile))
  64                            (file-exists-p (concat tfile ".gz")))
  65                       (concat tfile ".gz")
  66                     tfile))
  67               (setq tfile (expand-file-name file
  68                                             (file-name-directory basefile)))
  69               (if (or (file-exists-p tfile)
  70                       (string-match "\\.el\\'" tfile))
  71                   tfile
  72                 (concat tfile ".el")))))
  73     (if ext (concat "ext:" file)
  74       file)))
  75
  76 (defun check-declare-scan (file)
  77   "Scan FILE for `declare-function' calls.
  78 Return a list with elements of the form (FNFILE FN ARGLIST FILEONLY),
  79 where only the first two elements need be present.  This claims that FNFILE
  80 defines FN, with ARGLIST.  FILEONLY non-nil means only check that FNFILE
  81 exists, not that it defines FN.  This is for function definitions that we
  82 don't know how to recognize (e.g. some macros)."
  83   (let ((m (format "Scanning %s..." file))
  84         alist form len fn fnfile arglist fileonly)
  85     (message "%s" m)
  86     (with-temp-buffer
  87       (insert-file-contents file)
  88       ;; FIXME we could theoretically be inside a string.
  89       (while (re-search-forward "^[ \t]*\\((declare-function\\)[ \t\n]" nil t)
  90         (goto-char (match-beginning 1))
  91         (if (and (setq form (ignore-errors (read (current-buffer))))
  92                  ;; Exclude element of byte-compile-initial-macro-environment.
  93                  (or (listp (cdr form)) (setq form nil))
  94                  (> (setq len (length form)) 2)
  95                  (< len 6)
  96                  (symbolp (setq fn (cadr form)))
  97                  (setq fn (symbol-name fn)) ; later we use as a search string
  98                  (stringp (setq fnfile (nth 2 form)))
  99                  (setq fnfile (check-declare-locate fnfile
 100                                                     (expand-file-name file)))
 101                  ;; Use `t' to distinguish unspecified arglist from empty one.
 102                  (or (eq t (setq arglist (if (> len 3)
 103                                              (nth 3 form)
 104                                            t)))
 105                      (listp arglist))
 106                  (symbolp (setq fileonly (nth 4 form))))
 107             (setq alist (cons (list fnfile fn arglist fileonly) alist))
 108           ;; FIXME make this more noticeable.
 109           (if form (message "Malformed declaration for `%s'" (cadr form))))))
 110     (message "%sdone" m)
 111     alist))
 112
 113 (defun check-declare-errmsg (errlist &optional full)
 114   "Return a string with the number of errors in ERRLIST, if any.
 115 Normally just counts the number of elements in ERRLIST.
 116 With optional argument FULL, sums the number of elements in each element."
 117   (if errlist
 118       (let ((l (length errlist)))
 119         (when full
 120           (setq l 0)
 121           (dolist (e errlist)
 122             (setq l (+ l (1- (length e))))))
 123         (format "%d problem%s found" l (if (= l 1) "" "s")))
 124     "OK"))
 125
 126 (autoload 'byte-compile-arglist-signature "bytecomp")
 127
 128 (defun check-declare-verify (fnfile fnlist)
 129   "Check that FNFILE contains function definitions matching FNLIST.
 130 Each element of FNLIST has the form (FILE FN ARGLIST FILEONLY), where
 131 only the first two elements need be present.  This means FILE claimed FN
 132 was defined in FNFILE with the specified ARGLIST.  FILEONLY non-nil means
 133 to only check that FNFILE exists, not that it actually defines FN.
 134
 135 Returns nil if all claims are found to be true, otherwise a list
 136 of errors with elements of the form \(FILE FN TYPE), where TYPE
 137 is a string giving details of the error."
 138   (let ((m (format "Checking %s..." fnfile))
 139         (cflag (member (file-name-extension fnfile) '("c" "m")))
 140         (ext (string-match "^ext:" fnfile))
 141         re fn sig siglist arglist type errlist minargs maxargs)
 142     (message "%s" m)
 143     (if ext
 144         (setq fnfile (substring fnfile 4)))
 145     (if (file-regular-p fnfile)
 146         (with-temp-buffer
 147           (insert-file-contents fnfile)
 148           ;; defsubst's don't _have_ to be known at compile time.
 149           (setq re (format (if cflag
 150                                "^[ \t]*\\(DEFUN\\)[ \t]*([ \t]*\"%s\""
 151                              "^[ \t]*(\\(fset[ \t]+'\\|\
 152 def\\(?:un\\|subst\\|foo\\|method\\|class\\|\
 153 ine-\\(?:derived\\|generic\\|\\(?:global\\(?:ized\\)?-\\)?minor\\)-mode\\|\
 154 \\(?:ine-obsolete-function-\\)?alias[ \t]+'\\|\
 155 ine-overloadable-function\\)\\)\
 156 \[ \t]*%s\\([ \t;]+\\|$\\)")
 157                            (regexp-opt (mapcar 'cadr fnlist) t)))
 158           (while (re-search-forward re nil t)
 159             (skip-chars-forward " \t\n")
 160             (setq fn (match-string 2)
 161                   type (match-string 1)
 162                   ;; (min . max) for a fixed number of arguments, or
 163                   ;; arglists with optional elements.
 164                   ;; (min) for arglists with &rest.
 165                   ;; sig = 'err means we could not find an arglist.
 166                   sig (cond (cflag
 167                              (or
 168                               (when (search-forward "," nil t 3)
 169                                 (skip-chars-forward " \t\n")
 170                                 ;; Assuming minargs and maxargs on same line.
 171                                 (when (looking-at "\\([0-9]+\\)[ \t]*,[ \t]*\
 172 \\([0-9]+\\|MANY\\|UNEVALLED\\)")
 173                                   (setq minargs (string-to-number
 174                                                  (match-string 1))
 175                                         maxargs (match-string 2))
 176                                   (cons minargs (unless (string-match "[^0-9]"
 177                                                                       maxargs)
 178                                                  (string-to-number
 179                                                   maxargs)))))
 180                               'err))
 181                             ((string-match
 182                               "\\`define-\\(derived\\|generic\\)-mode\\'"
 183                               type)
 184                              '(0 . 0))
 185                             ((string-match
 186                               "\\`define\\(-global\\(ized\\)?\\)?-minor-mode\\'"
 187                               type)
 188                              '(0 . 1))
 189                             ;; Prompt to update.
 190                             ((string-match
 191                               "\\`define-obsolete-function-alias\\>"
 192                               type)
 193                              'obsolete)
 194                             ;; Can't easily check arguments in these cases.
 195                             ((string-match "\\`\\(def\\(alias\\|\
 196 method\\|class\\)\\|fset\\)\\>" type)
 197                              t)
 198                             ((looking-at "\\((\\|nil\\)")
 199                              (byte-compile-arglist-signature
 200                               (read (current-buffer))))
 201                             (t
 202                              'err))
 203                   ;; alist of functions and arglist signatures.
 204                   siglist (cons (cons fn sig) siglist)))))
 205     (dolist (e fnlist)
 206       (setq arglist (nth 2 e)
 207             type
 208             (if (not re)
 209                 "file not found"
 210               (if (not (setq sig (assoc (cadr e) siglist)))
 211                   (unless (nth 3 e)     ; fileonly
 212                     "function not found")
 213                 (setq sig (cdr sig))
 214                 (cond ((eq sig 'obsolete) ; check even when no arglist specified
 215                        "obsolete alias")
 216                       ;; arglist t means no arglist specified, as
 217                       ;; opposed to an empty arglist.
 218                       ((eq arglist t) nil)
 219                       ((eq sig t) nil) ; eg defalias - can't check arguments
 220                       ((eq sig 'err)
 221                        "arglist not found") ; internal error
 222                       ((not (equal (byte-compile-arglist-signature
 223                                     arglist)
 224                                    sig))
 225                        "arglist mismatch")))))
 226       (when type
 227         (setq errlist (cons (list (car e) (cadr e) type) errlist))))
 228     (message "%s%s" m
 229              (if (or re (not ext))
 230                  (check-declare-errmsg errlist)
 231                (progn
 232                  (setq errlist nil)
 233                  "skipping external file")))
 234     errlist))
 235
 236 (defun check-declare-sort (alist)
 237   "Sort a list with elements FILE (FNFILE ...).
 238 Returned list has elements FNFILE (FILE ...)."
 239   (let (file fnfile rest sort a)
 240     (dolist (e alist)
 241       (setq file (car e))
 242       (dolist (f (cdr e))
 243         (setq fnfile (car f)
 244               rest (cdr f))
 245         (if (setq a (assoc fnfile sort))
 246             (setcdr a (append (cdr a) (list (cons file rest))))
 247           (setq sort (cons (list fnfile (cons file rest)) sort)))))
 248     sort))
 249
 250 (defun check-declare-warn (file fn fnfile type)
 251   "Warn that FILE made a false claim about FN in FNFILE.
 252 TYPE is a string giving the nature of the error.  Warning is displayed in
 253 `check-declare-warning-buffer'."
 254   (display-warning 'check-declare
 255                    (format "%s said `%s' was defined in %s: %s"
 256                            (file-name-nondirectory file) fn
 257                            (file-name-nondirectory fnfile)
 258                            type)
 259                    nil check-declare-warning-buffer))
 260
 261 (defun check-declare-files (&rest files)
 262   "Check veracity of all `declare-function' statements in FILES.
 263 Return a list of any errors found."
 264   (let (alist err errlist)
 265     (dolist (file files)
 266       (setq alist (cons (cons file (check-declare-scan file)) alist)))
 267     ;; Sort so that things are ordered by the files supposed to
 268     ;; contain the defuns.
 269     (dolist (e (check-declare-sort alist))
 270       (if (setq err (check-declare-verify (car e) (cdr e)))
 271           (setq errlist (cons (cons (car e) err) errlist))))
 272     (if (get-buffer check-declare-warning-buffer)
 273         (kill-buffer check-declare-warning-buffer))
 274     ;; Sort back again so that errors are ordered by the files
 275     ;; containing the declare-function statements.
 276     (dolist (e (check-declare-sort errlist))
 277         (dolist (f (cdr e))
 278           (check-declare-warn (car e) (cadr f) (car f) (nth 2 f))))
 279     errlist))
 280
 281 ;;;###autoload
 282 (defun check-declare-file (file)
 283   "Check veracity of all `declare-function' statements in FILE.
 284 See `check-declare-directory' for more information."
 285   (interactive "fFile to check: ")
 286   (or (file-exists-p file)
 287       (error "File `%s' not found" file))
 288   (let ((m (format "Checking %s..." file))
 289         errlist)
 290     (message "%s" m)
 291     (setq errlist (check-declare-files file))
 292     (message "%s%s" m (check-declare-errmsg errlist))
 293     errlist))
 294
 295 ;;;###autoload
 296 (defun check-declare-directory (root)
 297   "Check veracity of all `declare-function' statements under directory ROOT.
 298 Returns non-nil if any false statements are found."
 299   (interactive "DDirectory to check: ")
 300   (or (file-directory-p (setq root (expand-file-name root)))
 301       (error "Directory `%s' not found" root))
 302   (let ((m "Checking `declare-function' statements...")
 303         (m2 "Finding files with declarations...")
 304         errlist files)
 305     (message "%s" m)
 306     (message "%s" m2)
 307     (setq files (process-lines find-program root
 308                                "-name" "*.el"
 309                                "-exec" grep-program
 310                                "-l" "^[ \t]*(declare-function" "{}" ";"))
 311     (message "%s%d found" m2 (length files))
 312     (when files
 313       (setq errlist (apply 'check-declare-files files))
 314       (message "%s%s" m (check-declare-errmsg errlist t))
 315       errlist)))
 316
 317 (provide 'check-declare)
 318
 319 ;;; check-declare.el ends here.