src/code/win32-pathname.lisp

   1 ;;;; pathname parsing for Win32 filesystems
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!IMPL")
  13
  14 (defstruct (win32-host
  15              (:include host
  16                        (parse #'parse-win32-namestring)
  17                        (parse-native #'parse-native-win32-namestring)
  18                        (unparse #'unparse-win32-namestring)
  19                        (unparse-native #'unparse-native-win32-namestring)
  20                        (unparse-host #'unparse-win32-host)
  21                        (unparse-directory #'unparse-win32-directory)
  22                        (unparse-file #'unparse-win32-file)
  23                        (unparse-enough #'unparse-win32-enough)
  24                        (unparse-directory-separator "\\")
  25                        (simplify-namestring #'simplify-win32-namestring)
  26                        (customary-case :lower))))
  27
  28 (defvar *physical-host* (make-win32-host))
  29
  30 ;;;
  31 (define-symbol-macro +long-file-name-prefix+ (quote "\\\\?\\"))
  32 (define-symbol-macro +unc-file-name-prefix+ (quote "\\\\?\\UNC"))
  33
  34 (defun extract-device (namestr start end)
  35   (declare (type simple-string namestr)
  36            (type index start end))
  37   (if (>= end (+ start 2))
  38       (let ((c0 (char namestr start))
  39             (c1 (char namestr (1+ start))))
  40         (cond ((and (eql c1 #\:) (alpha-char-p c0))
  41                ;; "X:" style, saved as X
  42                (values (string (char namestr start)) (+ start 2)))
  43               ((and (member c0 '(#\/ #\\)) (eql c0 c1) (>= end (+ start 3)))
  44                ;; "//UNC" style, saved as :UNC device, with host and share
  45                ;; becoming directory components.
  46                (values :unc (+ start 1)))
  47               (t
  48                (values nil start))))
  49       (values nil start)))
  50
  51 (defun split-at-slashes-and-backslashes (namestr start end)
  52   (declare (type simple-string namestr)
  53            (type index start end))
  54   ;; FIXME: There is a fundamental brokenness in using the same
  55   ;; character as escape character and directory separator in
  56   ;; non-native pathnames. (PATHNAME-DIRECTORY #P"\\*/") should
  57   ;; probably be (:RELATIVE "*") everywhere, but on Windows it's
  58   ;; (:ABSOLUTE :WILD)! See lp#673625.
  59   (let ((absolute (and (/= start end)
  60                        (or (char= (schar namestr start) #\/)
  61                            (char= (schar namestr start) #\\)))))
  62     (when absolute
  63       (incf start))
  64     ;; Next, split the remainder into slash-separated chunks.
  65     (collect ((pieces))
  66       (loop
  67          (let ((slash (position-if (lambda (c)
  68                                      (or (char= c #\/)
  69                                          (char= c #\\)))
  70                                    namestr :start start :end end)))
  71            (pieces (cons start (or slash end)))
  72            (unless slash
  73              (return))
  74            (setf start (1+ slash))))
  75       (values absolute (pieces)))))
  76
  77 (defun parse-win32-namestring (namestring start end)
  78   (declare (type simple-string namestring)
  79            (type index start end))
  80   (setf namestring (coerce namestring 'simple-string))
  81   (multiple-value-bind (device new-start)
  82       (extract-device namestring start end)
  83     (multiple-value-bind (absolute pieces)
  84         (split-at-slashes-and-backslashes namestring new-start end)
  85       (multiple-value-bind (name type version)
  86           (let* ((tail (car (last pieces)))
  87                  (tail-start (car tail))
  88                  (tail-end (cdr tail)))
  89             (unless (= tail-start tail-end)
  90               (setf pieces (butlast pieces))
  91               (extract-name-type-and-version namestring tail-start tail-end #\^)))
  92
  93         (when (stringp name)
  94           (let ((position (position-if (lambda (char)
  95                                          (or (char= char (code-char 0))
  96                                              (char= char #\/)))
  97                                        name)))
  98             (when position
  99               (error 'namestring-parse-error
 100                      :complaint "can't embed #\\Nul or #\\/ in Windows namestring"
 101                      :namestring namestring
 102                      :offset position))))
 103
 104         (let (home)
 105           ;; Deal with ~ and ~user.
 106           (when (car pieces)
 107             (destructuring-bind (start . end) (car pieces)
 108               (when (and (not absolute)
 109                          (not (eql start end))
 110                          (string= namestring "~"
 111                                   :start1 start
 112                                   :end1 (1+ start)))
 113                 (setf absolute t)
 114                 (if (> end (1+ start))
 115                     (setf home (list :home (subseq namestring (1+ start) end)))
 116                     (setf home :home))
 117                 (pop pieces))))
 118
 119           ;; Now we have everything we want. So return it.
 120           (values nil                 ; no host for Win32 namestrings
 121                   device
 122                   (collect ((dirs))
 123                     (dolist (piece pieces)
 124                       (let ((piece-start (car piece))
 125                             (piece-end (cdr piece)))
 126                         (unless (= piece-start piece-end)
 127                           (cond ((string= namestring ".."
 128                                           :start1 piece-start
 129                                           :end1 piece-end)
 130                                  (dirs :up))
 131                                 ((string= namestring "**"
 132                                           :start1 piece-start
 133                                           :end1 piece-end)
 134                                  (dirs :wild-inferiors))
 135                                 (t
 136                                  (dirs (maybe-make-pattern namestring
 137                                                            piece-start
 138                                                            piece-end
 139                                                            #\^)))))))
 140                     (cond (absolute
 141                            (if home
 142                                (list* :absolute home (dirs))
 143                                (cons :absolute (dirs))))
 144                           ((dirs)
 145                            (cons :relative (dirs)))
 146                           (t
 147                            nil)))
 148                   name
 149                   type
 150                   version))))))
 151
 152 (defun parse-native-win32-namestring (namestring start end as-directory)
 153   (declare (type simple-string namestring)
 154            (type index start end))
 155   (setf namestring (coerce namestring 'simple-string))
 156   (multiple-value-bind (device new-start)
 157       (cond ((= (length +unc-file-name-prefix+)
 158                 (mismatch +unc-file-name-prefix+ namestring
 159                           :start2 start))
 160              (values :unc (+ start (length +unc-file-name-prefix+))))
 161             ((= (length +long-file-name-prefix+)
 162                 (mismatch +long-file-name-prefix+ namestring
 163                           :start2 start))
 164              (extract-device namestring
 165                              (+ start (length +long-file-name-prefix+))
 166                              end))
 167             (t (extract-device namestring start end)))
 168     (multiple-value-bind (absolute ranges)
 169         (split-at-slashes-and-backslashes namestring new-start end)
 170       (let* ((components (loop for ((start . end) . rest) on ranges
 171                                for piece = (subseq namestring start end)
 172                                collect (if (and (string= piece "..") rest)
 173                                            :up
 174                                            piece)))
 175              (directory (if (and as-directory
 176                                  (string/= "" (car (last components))))
 177                             components
 178                             (butlast components)))
 179              (name-and-type
 180               (unless as-directory
 181                 (let* ((end (first (last components)))
 182                        (dot (position #\. end :from-end t)))
 183                   ;; FIXME: can we get this dot-interpretation knowledge
 184                   ;; from existing code?  EXTRACT-NAME-TYPE-AND-VERSION
 185                   ;; does slightly more work than that.
 186                   (cond
 187                     ((string= end "")
 188                      (list nil nil))
 189                     ((and dot (> dot 0))
 190                      (list (subseq end 0 dot) (subseq end (1+ dot))))
 191                     (t
 192                      (list end nil)))))))
 193         (values nil
 194                 device
 195                 (cons (if absolute :absolute :relative) directory)
 196                 (first name-and-type)
 197                 (second name-and-type)
 198                 nil)))))
 199
 200
 201
 202 (defun unparse-win32-host (pathname)
 203   (declare (type pathname pathname)
 204            (ignore pathname))
 205   ;; FIXME: same as UNPARSE-UNIX-HOST.  That's probably not good.
 206   "")
 207
 208 (defun unparse-win32-device (pathname &optional native)
 209   (declare (type pathname pathname))
 210   (let ((device (pathname-device pathname))
 211         (directory (pathname-directory pathname)))
 212     (cond ((or (null device) (eq device :unspecific))
 213            "")
 214           ((eq device :unc)
 215            (if native "\\" "/"))
 216           ((and (= 1 (length device)) (alpha-char-p (char device 0)))
 217            (concatenate 'simple-string device ":"))
 218           ((and (consp directory) (eq :relative (car directory)))
 219            (error "No printed representation for a relative UNC pathname."))
 220           (t
 221            (if native
 222                (concatenate 'simple-string "\\\\" device)
 223                (concatenate 'simple-string "//" device))))))
 224
 225 (defun unparse-win32-directory (pathname)
 226   (unparse-physical-directory pathname #\^))
 227
 228 (defun unparse-win32-file (pathname)
 229   (declare (type pathname pathname))
 230   (collect ((strings))
 231     (let* ((name (%pathname-name pathname))
 232            (type (%pathname-type pathname))
 233            (type-supplied (not (or (null type) (eq type :unspecific)))))
 234       ;; Note: by ANSI 19.3.1.1.5, we ignore the version slot when
 235       ;; translating logical pathnames to a filesystem without
 236       ;; versions (like Win32).
 237       (when name
 238         (when (and (null type)
 239                    (typep name 'string)
 240                    (> (length name) 0)
 241                    (position #\. name :start 1))
 242           (error "too many dots in the name: ~S" pathname))
 243         (when (and (typep name 'string)
 244                    (string= name ""))
 245           (error "name is of length 0: ~S" pathname))
 246         (strings (unparse-physical-piece name #\^)))
 247       (when type-supplied
 248         (unless name
 249           (error "cannot specify the type without a file: ~S" pathname))
 250         (when (typep type 'simple-string)
 251           (when (position #\. type)
 252             (error "type component can't have a #\. inside: ~S" pathname)))
 253         (strings ".")
 254         (strings (unparse-physical-piece type #\^))))
 255     (apply #'concatenate 'simple-string (strings))))
 256
 257 (defun unparse-win32-namestring (pathname)
 258   (declare (type pathname pathname))
 259   (concatenate 'simple-string
 260                (unparse-win32-device pathname)
 261                (unparse-physical-directory pathname #\^)
 262                (unparse-win32-file pathname)))
 263
 264 (defun unparse-native-win32-namestring (pathname as-file)
 265   (declare (type pathname pathname))
 266   (let* ((device (pathname-device pathname))
 267          (directory (pathname-directory pathname))
 268          (name (pathname-name pathname))
 269          (name-present-p (typep name '(not (member nil :unspecific))))
 270          (name-string (if name-present-p name ""))
 271          (type (pathname-type pathname))
 272          (type-present-p (typep type '(not (member nil :unspecific))))
 273          (type-string (if type-present-p type ""))
 274          (absolutep (and device (eql :absolute (car directory)))))
 275     (when name-present-p
 276       (setf as-file nil))
 277     (when (and absolutep (member :up directory))
 278       ;; employ merge-pathnames to parse :BACKs into which we turn :UPs
 279       (setf directory
 280             (pathname-directory
 281              (merge-pathnames
 282               (make-pathname :defaults pathname :directory '(:relative))
 283               (make-pathname :defaults pathname
 284                              :directory (substitute :back :up directory))))))
 285     (coerce
 286      (with-simple-output-to-string (s)
 287        (when absolutep
 288          (write-string (case device
 289                          (:unc +unc-file-name-prefix+)
 290                          (otherwise +long-file-name-prefix+)) s))
 291        (when (or (not absolutep) (not (member device '(:unc nil))))
 292          (write-string (unparse-win32-device pathname t) s))
 293        (when directory
 294          (ecase (pop directory)
 295            (:absolute
 296             (let ((next (pop directory)))
 297               ;; Don't use USER-HOMEDIR-NAMESTRING, since
 298               ;; it can be specified as C:/User/user
 299               ;; and (native-namestring (user-homedir-pathname))
 300               ;; will be not equal to it, because it's parsed first.
 301               (cond ((eq :home next)
 302                      (write-string (native-namestring (user-homedir-pathname))
 303                                    s))
 304                     ((and (consp next) (eq :home (car next)))
 305                      (let ((where (user-homedir-pathname (second next))))
 306                        (if where
 307                            (write-string (native-namestring where) s)
 308                            (error "User homedir unknown for: ~S."
 309                                   (second next)))))
 310                     ;; namestring of user-homedir-pathname already has
 311                     ;; // at the end
 312                     (next
 313                      (write-char #\\ s)
 314                      (push next directory))
 315                     (t
 316                      (write-char #\\ s)))))
 317            (:relative)))
 318        (loop for (piece . subdirs) on directory
 319              do (typecase piece
 320                   ((member :up :back) (write-string ".." s))
 321                   (string (write-string piece s))
 322                   (t (error "Bad directory segment in NATIVE-NAMESTRING: ~S."
 323                             piece)))
 324              if (or subdirs (stringp name))
 325              do (write-char #\\ s)
 326              else
 327              do (unless as-file
 328                   (write-char #\\ s)))
 329        (if name-present-p
 330            (progn
 331              (unless (stringp name-string) ;some kind of wild field
 332                (error "Bad name component in NATIVE-NAMESTRING: ~S." name))
 333              (write-string name-string s)
 334              (when type-present-p
 335                (unless (stringp type-string) ;some kind of wild field
 336                  (error "Bad type component in NATIVE-NAMESTRING: ~S." type))
 337                (write-char #\. s)
 338                (write-string type-string s)))
 339            (when type-present-p
 340              (error
 341               "Type component without a name component in NATIVE-NAMESTRING: ~S."
 342               type)))
 343        (when absolutep
 344          (let ((string (get-output-stream-string s)))
 345            (return-from unparse-native-win32-namestring
 346              (cond ((< (- 260 12) (length string))
 347                     ;; KLUDGE: account for additional length of 8.3 name to make
 348                     ;; directories always accessible
 349                     (coerce string 'simple-string))
 350                    ((eq :unc device)
 351                     (replace
 352                      (subseq string (1- (length +unc-file-name-prefix+)))
 353                      "\\"))
 354                    (t (subseq string (length +long-file-name-prefix+))))))))
 355      'simple-string)))
 356
 357 ;;; FIXME.
 358 (defun unparse-win32-enough (pathname defaults)
 359   (declare (type pathname pathname defaults))
 360   (flet ((lose ()
 361            (error "~S cannot be represented relative to ~S."
 362                   pathname defaults)))
 363     (collect ((strings))
 364       (let* ((pathname-directory (%pathname-directory pathname))
 365              (defaults-directory (%pathname-directory defaults))
 366              (prefix-len (length defaults-directory))
 367              (result-directory
 368               (cond ((null pathname-directory) '(:relative))
 369                     ((eq (car pathname-directory) :relative)
 370                      pathname-directory)
 371                     ((and (> prefix-len 0)
 372                           (>= (length pathname-directory) prefix-len)
 373                           (compare-component (subseq pathname-directory
 374                                                      0 prefix-len)
 375                                              defaults-directory))
 376                      ;; Pathname starts with a prefix of default. So
 377                      ;; just use a relative directory from then on out.
 378                      (cons :relative (nthcdr prefix-len pathname-directory)))
 379                     ((eq (car pathname-directory) :absolute)
 380                      ;; We are an absolute pathname, so we can just use it.
 381                      pathname-directory)
 382                     (t
 383                      (bug "Bad fallthrough in ~S" 'unparse-unix-enough)))))
 384         (strings (unparse-physical-directory-list result-directory #\^)))
 385       (let* ((pathname-type (%pathname-type pathname))
 386              (type-needed (and pathname-type
 387                                (not (eq pathname-type :unspecific))))
 388              (pathname-name (%pathname-name pathname))
 389              (name-needed (or type-needed
 390                               (and pathname-name
 391                                    (not (compare-component pathname-name
 392                                                            (%pathname-name
 393                                                             defaults)))))))
 394         (when name-needed
 395           (unless pathname-name (lose))
 396           (when (and (null pathname-type)
 397                      (typep pathname-name 'simple-string)
 398                      (position #\. pathname-name :start 1))
 399             (error "too many dots in the name: ~S" pathname))
 400           (strings (unparse-physical-piece pathname-name #\^)))
 401         (when type-needed
 402           (when (or (null pathname-type) (eq pathname-type :unspecific))
 403             (lose))
 404           (when (typep pathname-type 'simple-string)
 405             (when (position #\. pathname-type)
 406               (error "type component can't have a #\. inside: ~S" pathname)))
 407           (strings ".")
 408           (strings (unparse-physical-piece pathname-type #\^))))
 409       (apply #'concatenate 'simple-string (strings)))))
 410
 411 ;; FIXME: This has been converted rather blindly from the Unix
 412 ;; version, with no reference to any Windows docs what so ever.
 413 (defun simplify-win32-namestring (src)
 414   (declare (type simple-string src))
 415   (let* ((src-len (length src))
 416          (dst (make-string src-len :element-type 'character))
 417          (dst-len 0)
 418          (dots 0)
 419          (last-slash nil))
 420     (flet ((deposit (char)
 421              (setf (schar dst dst-len) char)
 422              (incf dst-len))
 423            (slashp (char)
 424              (find char "\\/")))
 425       (dotimes (src-index src-len)
 426         (let ((char (schar src src-index)))
 427           (cond ((char= char #\.)
 428                  (when dots
 429                    (incf dots))
 430                  (deposit char))
 431                 ((slashp char)
 432                  (case dots
 433                    (0
 434                     ;; either ``/...' or ``...//...'
 435                     (unless last-slash
 436                       (setf last-slash dst-len)
 437                       (deposit char)))
 438                    (1
 439                     ;; either ``./...'' or ``..././...''
 440                     (decf dst-len))
 441                    (2
 442                     ;; We've found ..
 443                     (cond
 444                       ((and last-slash (not (zerop last-slash)))
 445                        ;; There is something before this ..
 446                        (let ((prev-prev-slash
 447                               (position-if #'slashp dst :end last-slash :from-end t)))
 448                          (cond ((and (= (+ (or prev-prev-slash 0) 2)
 449                                         last-slash)
 450                                      (char= (schar dst (- last-slash 2)) #\.)
 451                                      (char= (schar dst (1- last-slash)) #\.))
 452                                 ;; The something before this .. is another ..
 453                                 (deposit char)
 454                                 (setf last-slash dst-len))
 455                                (t
 456                                 ;; The something is some directory or other.
 457                                 (setf dst-len
 458                                       (if prev-prev-slash
 459                                           (1+ prev-prev-slash)
 460                                           0))
 461                                 (setf last-slash prev-prev-slash)))))
 462                       (t
 463                        ;; There is nothing before this .., so we need to keep it
 464                        (setf last-slash dst-len)
 465                        (deposit char))))
 466                    (t
 467                     ;; something other than a dot between slashes
 468                     (setf last-slash dst-len)
 469                     (deposit char)))
 470                  (setf dots 0))
 471                 (t
 472                  (setf dots nil)
 473                  (setf (schar dst dst-len) char)
 474                  (incf dst-len)))))
 475       ;; ...finish off
 476       (when (and last-slash (not (zerop last-slash)))
 477         (case dots
 478           (1
 479            ;; We've got  ``foobar/.''
 480            (decf dst-len))
 481           (2
 482            ;; We've got ``foobar/..''
 483            (unless (and (>= last-slash 2)
 484                         (char= (schar dst (1- last-slash)) #\.)
 485                         (char= (schar dst (- last-slash 2)) #\.)
 486                         (or (= last-slash 2)
 487                             (slashp (schar dst (- last-slash 3)))))
 488              (let ((prev-prev-slash
 489                     (position-if #'slashp dst :end last-slash :from-end t)))
 490                (if prev-prev-slash
 491                    (setf dst-len (1+ prev-prev-slash))
 492                    (return-from simplify-win32-namestring
 493                      (coerce ".\\" 'simple-string)))))))))
 494     (cond ((zerop dst-len)
 495            ".\\")
 496           ((= dst-len src-len)
 497            dst)
 498           (t
 499            (subseq dst 0 dst-len)))))