lisp/info-xref.el

   1 ;;; info-xref.el --- check external references in an Info document -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 2003-2018 Free Software Foundation, Inc.
   4
   5 ;; Author: Kevin Ryde <user42@zip.com.au>
   6 ;; Keywords: docs
   7 ;; Version: 3
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This is some simple checking of external cross references in info files,
  27 ;; docstrings and custom-links by attempting to visit the nodes specified.
  28 ;;
  29 ;; `M-x info-xref-check' checks a single info file.  See the docstring for
  30 ;; details.
  31 ;;
  32 ;; `M-x info-xref-check-all' checks all info files in Info-directory-list.
  33 ;; This is a good way to check the consistency of the whole system.
  34 ;;
  35 ;; `M-x info-xref-check-all-custom' loads up all defcustom variables and
  36 ;; checks any info references in them.
  37 ;;
  38 ;; `M-x info-xref-docstrings' checks docstring "Info node ..." hyperlinks in
  39 ;; source files (and other files).
  40
  41 ;;; History:
  42
  43 ;; Version 3 - new M-x info-xref-docstrings, use compilation-mode
  44
  45 ;;; Code:
  46
  47 (require 'info)
  48 (eval-when-compile (require 'cl-lib))   ; for `cl-incf'
  49
  50 (defgroup info-xref nil
  51   "Check external cross-references in Info documents."
  52   :group 'docs)                         ; FIXME right parent?
  53
  54 ;; Should this even be an option?
  55 (defcustom info-xref-case-fold nil
  56   "Non-nil means node checks should ignore case.
  57 When following cross-references, the Emacs Info reader first tries a
  58 case-sensitive match, then if that fails a case-insensitive one.
  59 The standalone Info reader does not do this, nor does this work
  60 for links in the html versions of Texinfo manuals.  Therefore
  61 to ensure your cross-references work on the widest range of platforms,
  62 you should set this variable to nil."
  63   :group 'info-xref
  64   :type 'boolean
  65   :version "24.4")
  66
  67
  68 ;;-----------------------------------------------------------------------------
  69 ;; vaguely generic
  70
  71 (defun info-xref-lock-file-p (filename)
  72   "Return non-nil if FILENAME is an Emacs lock file.
  73 A lock file is \".#foo.txt\" etc per `lock-buffer'."
  74   (string-match "\\(\\`\\|\\/\\)\\.#" filename))
  75
  76 (defun info-xref-subfile-p (filename)
  77   "Return t if FILENAME is an info subfile.
  78 If removing the last \"-<NUM>\" from the filename gives a file
  79 which exists, then consider FILENAME a subfile.  This is an
  80 imperfect test, probably ought to open up the purported top file
  81 and see what subfiles it says."
  82   (and (string-match "\\`\\(\\([^-]*-\\)*[^-]*\\)-[0-9]+\\(.*\\)\\'" filename)
  83        (file-exists-p (concat (match-string 1 filename)
  84                               (match-string 3 filename)))))
  85
  86 (defmacro info-xref-with-file (filename &rest body)
  87   ;; checkdoc-params: (filename body)
  88   "Evaluate BODY in a buffer containing the contents of FILENAME.
  89 If FILENAME is already in a buffer then that's used, otherwise a
  90 temporary buffer.
  91
  92 The current implementation uses `insert-file-contents' rather
  93 than `find-file-noselect' so as not to be held up by queries
  94 about local variables or possible weirdness in a major mode.
  95 `lm-with-file' does a similar thing, but it sets
  96 `emacs-lisp-mode' which is not wanted here."
  97
  98   (declare (debug t) (indent 1))
  99   `(let* ((info-xref-with-file--filename ,filename)
 100           (info-xref-with-file--body     (lambda () ,@body))
 101           (info-xref-with-file--existing
 102            (find-buffer-visiting info-xref-with-file--filename)))
 103      (if info-xref-with-file--existing
 104          (with-current-buffer info-xref-with-file--existing
 105            (save-excursion
 106              (funcall info-xref-with-file--body)))
 107        (with-temp-buffer
 108          (insert-file-contents ,filename)
 109          (funcall info-xref-with-file--body)))))
 110
 111
 112 ;;-----------------------------------------------------------------------------
 113 ;; output buffer
 114
 115 (defconst info-xref-output-buffer "*info-xref results*"
 116   "Name of the buffer for info-xref results.")
 117
 118 (defvar info-xref-good 0
 119   "Count of good cross references, during info-xref processing.")
 120 (defvar info-xref-bad 0
 121   "Count of bad cross references, during info-xref processing.")
 122 (defvar info-xref-unavail 0
 123   "Count of unavailable cross references, during info-xref processing.")
 124
 125 (defvar info-xref-output-heading ""
 126   "A heading string, during info-xref processing.
 127 This is shown if there's an error, but not if successful.")
 128
 129 (defvar info-xref-filename nil
 130   "The current buffer's filename, during info-xref processing.
 131 When looking at file contents in a temp buffer there's no
 132 `buffer-file-name', hence this variable.")
 133
 134 (defvar info-xref-xfile-alist nil
 135   "Info files found or not found, during info-xref processing.
 136 Key is \"(foo)\" etc and value nil or t according to whether info
 137 manual \"(foo)\" exists or not.  This is used to suppress
 138 duplicate messages about foo not being available.  (Duplicates
 139 within one top-level file that is.)")
 140
 141 (defvar info-xref-in-progress nil)
 142 (defmacro info-xref-with-output (&rest body)
 143   "Run BODY with an info-xref output buffer.
 144 This is meant to nest, so you can wrap it around a set of
 145 different info-xref checks and have them write to the one output
 146 buffer created by the outermost `info-xref-with-output', with an
 147 overall good/bad count summary inserted at the very end."
 148
 149   (declare (debug t))
 150   `(save-excursion
 151      (unless info-xref-in-progress
 152        (display-buffer (get-buffer-create info-xref-output-buffer))
 153        (set-buffer info-xref-output-buffer)
 154        (setq buffer-read-only nil)
 155        (fundamental-mode)
 156        (erase-buffer)
 157        (insert ";; info-xref output -*- mode: compilation -*-\n\n")
 158        (compilation-mode)
 159        (setq info-xref-good    0
 160              info-xref-bad     0
 161              info-xref-unavail 0
 162              info-xref-xfile-alist nil))
 163
 164      (let ((info-xref-in-progress t)
 165            (info-xref-output-heading ""))
 166        ,@body)
 167
 168      (unless info-xref-in-progress
 169        (info-xref-output "done, %d good, %d bad, %d unavailable"
 170                          info-xref-good info-xref-bad info-xref-unavail))))
 171
 172 (defun info-xref-output (fmt &rest args)
 173   "Emit a `format-message'-ed message FMT+ARGS to the `info-xref-output-buffer'."
 174   (with-current-buffer info-xref-output-buffer
 175     (save-excursion
 176       (goto-char (point-max))
 177       (let ((inhibit-read-only t))
 178         (insert info-xref-output-heading
 179                 (apply #'format-message fmt args)
 180                 "\n")))
 181     (setq info-xref-output-heading "")
 182     ;; all this info-xref can be pretty slow, display now so the user sees
 183     ;; some progress
 184     (sit-for 0)))
 185 (put 'info-xref-output 'byte-compile-format-like t)
 186
 187 (defun info-xref-output-error (fmt &rest args)
 188   "Emit a `format'-ed error FMT+ARGS to the `info-xref-output-buffer'.
 189 The error is attributed to `info-xref-filename' and the current
 190 buffer's line and column of point."
 191   (apply 'info-xref-output
 192          (concat "%s:%s:%s: " fmt)
 193          info-xref-filename
 194          (1+ (count-lines (point-min) (line-beginning-position)))
 195          (1+ (current-column))
 196          args))
 197 (put 'info-xref-output-error 'byte-compile-format-like t)
 198
 199
 200 ;;-----------------------------------------------------------------------------
 201 ;; node checking
 202
 203 ;; When asking Info-goto-node to fork, *info* needs to be the current
 204 ;; buffer, otherwise it seems to clone the current buffer but then do the
 205 ;; goto-node in plain *info*.
 206 ;;
 207 ;; We only fork if *info* already exists, if it doesn't then can create and
 208 ;; destroy just that instead of a new name.
 209 ;;
 210 ;; If Info-goto-node can't find the file, then no new buffer is created.  If
 211 ;; it finds the file but not the node, then a buffer is created.  Handle
 212 ;; this difference by checking before killing.
 213 ;;
 214 (defun info-xref-goto-node-p (node)
 215   "Return t if it's possible to go to the given NODE."
 216   (let ((oldbuf (current-buffer)))
 217     (save-excursion
 218       (save-window-excursion
 219         (prog1
 220             (condition-case nil
 221                 (progn
 222                   (Info-goto-node node
 223                                   (when (get-buffer "*info*")
 224                                     (set-buffer "*info*")
 225                                     "xref - temporary")
 226                                   (not info-xref-case-fold))
 227                   t)
 228               (error nil))
 229           (unless (equal (current-buffer) oldbuf)
 230             (kill-buffer)))))))
 231
 232 (defun info-xref-check-node (node)
 233
 234   ;; Collapse spaces as per info.el and `help-make-xrefs'.
 235   ;; Note defcustom :info-link nodes don't get this whitespace collapsing,
 236   ;; they should be the exact node name ready to visit.
 237   ;; `info-xref-check-all-custom' uses `info-xref-goto-node-p' and so
 238   ;; doesn't come through here.
 239   ;;
 240   ;; Could use "[\t\n ]+" but try to avoid uselessly replacing " " with " ".
 241   (setq node (replace-regexp-in-string "[\t\n][\t\n ]*\\| [\t\n ]+" " "
 242                                        node t t))
 243
 244   (if (not (string-match "\\`([^)]*)" node))
 245       (info-xref-output-error "no `(file)' part at start of node: %s\n" node)
 246     (let ((file (match-string 0 node)))
 247
 248       (if (string-equal "()" file)
 249           (info-xref-output-error "empty filename part: %s" node)
 250
 251         ;; see if the file exists, if haven't looked before
 252         (unless (assoc file info-xref-xfile-alist)
 253           (let ((found (info-xref-goto-node-p file)))
 254             (push (cons file found) info-xref-xfile-alist)
 255             (unless found
 256               (info-xref-output-error "not available to check: %s\n    (this reported once per file)" file))))
 257
 258         ;; if the file exists, try the node
 259         (cond ((not (cdr (assoc file info-xref-xfile-alist)))
 260                (cl-incf info-xref-unavail))
 261               ((info-xref-goto-node-p node)
 262                (cl-incf info-xref-good))
 263               (t
 264                (cl-incf info-xref-bad)
 265                (info-xref-output-error "no such node: %s" node)))))))
 266
 267
 268 ;;-----------------------------------------------------------------------------
 269
 270 ;;;###autoload
 271 (defun info-xref-check (filename)
 272   "Check external references in FILENAME, an info document.
 273 Interactively from an `Info-mode' or `texinfo-mode' buffer the
 274 current info file is the default.
 275
 276 Results are shown in a `compilation-mode' buffer.  The format is
 277 a bit rough, but there shouldn't be many problems normally.  The
 278 file:line:column: is the info document, but of course normally
 279 any correction should be made in the original .texi file.
 280 Finding the right place in the .texi is a manual process.
 281
 282 When a target info file doesn't exist there's obviously no way to
 283 validate node references within it.  A message is given for
 284 missing target files once per source document.  It could be
 285 simply that you don't have the target installed, or it could be a
 286 mistake in the reference.
 287
 288 Indirect info files are understood, just pass the top-level
 289 foo.info to `info-xref-check' and it traverses all sub-files.
 290 Compressed info files are accepted too as usual for `Info-mode'.
 291
 292 \"makeinfo\" checks references internal to an info document, but
 293 not external references, which makes it rather easy for mistakes
 294 to creep in or node name changes to go unnoticed.
 295 `Info-validate' doesn't check external references either."
 296
 297   (interactive
 298    (list
 299     (let* ((default-filename
 300              (cond ((eq major-mode 'Info-mode)
 301                     Info-current-file)
 302                    ((eq major-mode 'texinfo-mode)
 303                     ;; look for @setfilename like makeinfo.el does
 304                     (save-excursion
 305                       (goto-char (point-min))
 306                       (if (re-search-forward
 307                            "^@setfilename[ \t]+\\([^ \t\n]+\\)[ \t]*"
 308                            (line-beginning-position 100) t)
 309                           (expand-file-name (match-string 1)))))))
 310            (prompt (if default-filename
 311                        (format "Info file (%s): " default-filename)
 312                      "Info file: ")))
 313       (read-file-name prompt nil default-filename t))))
 314
 315   (info-xref-check-list (list filename)))
 316
 317 ;;;###autoload
 318 (defun info-xref-check-all ()
 319   "Check external references in all info documents in the info path.
 320 `Info-directory-list' and `Info-additional-directory-list' are
 321 the info paths.  See `info-xref-check' for how each file is
 322 checked.
 323
 324 The search for \"all\" info files is rather permissive, since
 325 info files don't necessarily have a \".info\" extension and in
 326 particular the Emacs manuals normally don't.  If you have a
 327 source code directory in `Info-directory-list' then a lot of
 328 extraneous files might be read.  This will be time consuming but
 329 should be harmless."
 330
 331   (interactive)
 332   (info-xref-check-list (info-xref-all-info-files)))
 333
 334 ;; An alternative for getting only top-level files here would be to simply
 335 ;; return all files and have info-xref-check-list not follow "Indirect:".
 336 ;; The current way seems better because it (potentially) gets the proper
 337 ;; top-level filename into the error messages, and suppresses duplicate "not
 338 ;; available" messages for all subfiles of a single document.
 339
 340 (defun info-xref-all-info-files ()
 341   "Return a list of all available info files.
 342 Only top level files are returned, subfiles are excluded.
 343
 344 Since info files don't have to have a .info suffix, all files in
 345 the relevant directories are considered, which might mean a lot
 346 of extraneous things if for instance a source code directory is
 347 in the path."
 348
 349   (info-initialize) ;; establish Info-directory-list
 350   (apply 'nconc
 351          (mapcar
 352           (lambda (dir)
 353             (let ((result nil))
 354               (dolist (name (directory-files
 355                              dir
 356                              t           ;; absolute filenames
 357                              "\\`[^.]")) ;; not dotfiles, nor .# lockfiles
 358                 (when (and (file-exists-p name) ;; ignore broken symlinks
 359                            (not (string-match "\\.te?xi\\'" name)) ;; not .texi
 360                            (not (backup-file-name-p name))
 361                            (not (file-directory-p name))
 362                            (not (info-xref-subfile-p name)))
 363                   (push name result)))
 364               (nreverse result)))
 365           (append Info-directory-list Info-additional-directory-list))))
 366
 367 (defun info-xref-check-list (filename-list)
 368   "Check external references in info documents in FILENAME-LIST."
 369   (info-xref-with-output
 370     (dolist (info-xref-filename filename-list)
 371       (setq info-xref-xfile-alist nil)
 372       (let ((info-xref-output-heading
 373              (format "Info file %s\n" info-xref-filename)))
 374         (with-temp-message (format "Looking at %s" info-xref-filename)
 375           (with-temp-buffer
 376             (info-insert-file-contents info-xref-filename)
 377             (goto-char (point-min))
 378             (if (search-forward "\^_\nIndirect:\n" nil t)
 379                 (let ((dir (file-name-directory info-xref-filename)))
 380                   (while (looking-at "\\(.*\\): [0-9]+\n")
 381                     (let ((info-xref-filename
 382                            (expand-file-name (match-string 1) dir)))
 383                       (with-temp-buffer
 384                         (info-insert-file-contents info-xref-filename)
 385                         (info-xref-check-buffer)))
 386                     (forward-line)))
 387               (info-xref-check-buffer))))))))
 388
 389 (defconst info-xref-node-re "\\(?1:\\(([^)]*)\\)[^.,]+\\)"
 390   "Regexp with subexp 1 matching (manual)node.")
 391
 392 ;; "@xref{node,crossref,manual}." produces:
 393 ;; texinfo 4 or 5:
 394 ;; *Note crossref: (manual)node.
 395 ;; "@xref{node,,manual}." produces:
 396 ;; texinfo 4:
 397 ;; *Note node: (manual)node.
 398 ;; texinfo 5:
 399 ;; *Note (manual)node::.
 400 (defconst info-xref-note-re
 401   (concat "\\*[Nn]ote[ \n\t]+\\(?:"
 402           "[^:]*:[ \n\t]+" info-xref-node-re "\\|"
 403           info-xref-node-re "::\\)[.,]")
 404   "Regexp matching a \"*note...\" link.")
 405
 406 (defun info-xref-check-buffer ()
 407   "Check external references in the info file in the current buffer.
 408 This should be the raw file contents, not `Info-mode'."
 409   (goto-char (point-min))
 410   (while (re-search-forward info-xref-note-re nil t)
 411     (save-excursion
 412       (goto-char (match-beginning 1)) ;; start of nodename as error position
 413       (info-xref-check-node (match-string 1)))))
 414
 415 (defvar viper-mode) ;; quieten the byte compiler
 416 (defvar gnus-registry-install)
 417
 418 ;;;###autoload
 419 (defun info-xref-check-all-custom ()
 420   "Check info references in all customize groups and variables.
 421 Info references can be in `custom-manual' or `info-link' entries
 422 of the `custom-links' for a variable.
 423
 424 Any `custom-load' autoloads in variables are loaded in order to
 425 get full link information.  This will be a lot of Lisp packages
 426 and can take a long time."
 427
 428   (interactive)
 429   (info-xref-with-output
 430
 431    ;; `custom-load-symbol' is not used, since it quietly ignores errors, but
 432    ;; we want to show them since they mean incomplete checking.
 433    ;;
 434    ;; Just one pass through mapatoms is made.  There shouldn't be any new
 435    ;; custom-loads setup by packages loaded.
 436    ;;
 437    (info-xref-output "Loading custom-load autoloads ...")
 438    (require 'cus-start)
 439    (require 'cus-load)
 440
 441    ;; These are `setq' rather than `let' since a let would unbind the
 442    ;; variables after viper.el/gnus-registry.el have loaded, defeating the
 443    ;; defvars in those files.  Of course it'd be better if those files
 444    ;; didn't make interactive queries on loading at all, to allow for
 445    ;; programmatic loading like here.
 446    (unless (boundp 'viper-mode)
 447      (setq viper-mode nil))  ;; avoid viper.el ask about viperizing
 448    (unless (boundp 'gnus-registry-install)
 449      (setq gnus-registry-install nil))  ;; avoid gnus-registry.el querying
 450
 451    (mapatoms
 452     (lambda (symbol)
 453       (dolist (load (get symbol 'custom-loads))
 454         (cond ((symbolp load)
 455                (condition-case cause (require load)
 456                  (error
 457                   (info-xref-output "Symbol `%s': cannot require `%s': %s"
 458                                     symbol load cause))))
 459               ;; skip if previously loaded
 460               ((assoc load load-history))
 461               ((assoc (locate-library load) load-history))
 462               (t
 463                (condition-case err
 464                    (load load)
 465                  (error
 466                   (info-xref-output "Symbol `%s': cannot load \"%s\": %s"
 467                                     symbol load
 468                                     (error-message-string err)))))))))
 469
 470    ;; Don't bother to check whether the info file exists as opposed to just
 471    ;; a missing node.  If you have the code then you should have the
 472    ;; documentation, so a wrong node name will be the usual fault.
 473    ;;
 474    (info-xref-output "\nChecking custom-links references ...")
 475    (mapatoms
 476     (lambda (symbol)
 477       (dolist (link (get symbol 'custom-links))
 478         (when (memq (car link) '(custom-manual info-link))
 479           ;; skip :tag part of (custom-manual :tag "Foo" "(foo)Node")
 480           (if (eq :tag (cadr link))
 481               (setq link (cddr link)))
 482           (if (info-xref-goto-node-p (cadr link))
 483               (cl-incf info-xref-good)
 484             (cl-incf info-xref-bad)
 485             ;; symbol-file gives nil for preloaded variables, would need
 486             ;; to copy what describe-variable does to show the right place
 487             (info-xref-output "Symbol `%s' (file %s): cannot goto node: %s"
 488                               symbol
 489                               (symbol-file symbol 'defvar)
 490                               (cadr link)))))))))
 491
 492 ;;;###autoload
 493 (defun info-xref-docstrings (filename-list)
 494   ;; checkdoc-params: (filename-list)
 495   "Check docstring info node references in source files.
 496 The given files are searched for docstring hyperlinks like
 497
 498     Info node `(elisp)Documentation Tips'
 499
 500 and those links checked by attempting to visit the target nodes
 501 as per `info-xref-check' does.
 502
 503 Interactively filenames are read as a wildcard pattern like
 504 \"foo*.el\", with the current file as a default.  Usually this
 505 will be lisp sources, but anything with such hyperlinks can be
 506 checked, including the Emacs .c sources (or the etc/DOC file of
 507 all builtins).
 508
 509 Because info node hyperlinks are found by a simple regexp search
 510 in the files, the Lisp code checked doesn't have to be loaded,
 511 and links can be in the file commentary or elsewhere too.  Even
 512 .elc files can usually be checked successfully if you don't have
 513 the sources handy."
 514   (interactive
 515    (let* ((default (and buffer-file-name
 516                               (file-relative-name buffer-file-name)))
 517           (prompt (if default
 518                       (format "Filename with wildcards (%s): "
 519                               default)
 520                     "Filename with wildcards: "))
 521           (pattern (read-file-name prompt nil default))
 522           ;; absolute filenames
 523           (filename-list (file-expand-wildcards pattern t))
 524           newlist)
 525      (setq filename-list
 526            (dolist (file filename-list (nreverse newlist))
 527              (or (info-xref-lock-file-p file)
 528                  (file-directory-p file)
 529                  (push file newlist))))
 530      (unless filename-list
 531        (error "No files: %S" pattern))
 532      (list filename-list)))
 533
 534   (eval-and-compile
 535     (require 'help-mode)) ;; for `help-xref-info-regexp'
 536
 537   (info-xref-with-output
 538    (dolist (info-xref-filename filename-list)
 539      (setq info-xref-xfile-alist nil)  ;; "not found"s once per file
 540
 541      (info-xref-with-file info-xref-filename
 542        (goto-char (point-min))
 543        (while (re-search-forward help-xref-info-regexp nil t)
 544          (let ((node (match-string 2)))
 545            (save-excursion
 546              (goto-char (match-beginning 2)) ;; start of node as error position
 547
 548              ;; skip nodes with "%" as probably `format' strings such as in
 549              ;; info-look.el
 550              (unless (string-match "%" node)
 551
 552                ;; "(emacs)" is the default manual for docstring hyperlinks,
 553                ;; per `help-make-xrefs'
 554                (unless (string-match "\\`(" node)
 555                  (setq node (concat "(emacs)" node)))
 556
 557                (info-xref-check-node node)))))))))
 558
 559
 560 (provide 'info-xref)
 561
 562 ;;; info-xref.el ends here