src/code/package.lisp

   1 ;;;; that part of the CMU CL package.lisp file which can run on the
   2 ;;;; cross-compilation host
   3
   4 ;;;; This software is part of the SBCL system. See the README file for
   5 ;;;; more information.
   6 ;;;;
   7 ;;;; This software is derived from the CMU CL system, which was
   8 ;;;; written at Carnegie Mellon University and released into the
   9 ;;;; public domain. The software is in the public domain and is
  10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  11 ;;;; files for more information.
  12
  13 (in-package "SB!IMPL")
  14 \f
  15 ;;;; the PACKAGE-HASHTABLE structure
  16
  17 ;;; comment from CMU CL:
  18 ;;;      Packages are implemented using a special kind of hashtable. It is
  19 ;;;   an open hashtable with a parallel 8-bit I-vector of hash-codes. The
  20 ;;;   primary purpose of the hash for each entry is to reduce paging by
  21 ;;;   allowing collisions and misses to be detected without paging in the
  22 ;;;   symbol and pname for an entry. If the hash for an entry doesn't
  23 ;;;   match that for the symbol that we are looking for, then we can
  24 ;;;   go on without touching the symbol, pname, or even hastable vector.
  25 ;;;      It turns out that, contrary to my expectations, paging is a very
  26 ;;;   important consideration the design of the package representation.
  27 ;;;   Using a similar scheme without the entry hash, the fasloader was
  28 ;;;   spending more than half its time paging in INTERN.
  29 ;;;      The hash code also indicates the status of an entry. If it zero,
  30 ;;;   the entry is unused. If it is one, then it is deleted.
  31 ;;;   Double-hashing is used for collision resolution.
  32
  33 (def!type hash-vector () '(simple-array (unsigned-byte 8) (*)))
  34
  35 (def!struct (package-hashtable
  36              (:constructor %make-package-hashtable
  37                            (table hash size &aux (free size)))
  38              (:copier nil))
  39   ;; The g-vector of symbols.
  40   (table (missing-arg) :type simple-vector)
  41   ;; The i-vector of pname hash values.
  42   (hash (missing-arg) :type hash-vector)
  43   ;; The total number of entries allowed before resizing.
  44   ;;
  45   ;; FIXME: CAPACITY would be a more descriptive name. (This is
  46   ;; related to but not quite the same as HASH-TABLE-SIZE, so calling
  47   ;; it SIZE seems somewhat misleading.)
  48   (size (missing-arg) :type index)
  49   ;; The remaining number of entries that can be made before we have to rehash.
  50   (free (missing-arg) :type index)
  51   ;; The number of deleted entries.
  52   (deleted 0 :type index))
  53 \f
  54 ;;;; the PACKAGE structure
  55
  56 ;;; KLUDGE: We use DEF!STRUCT to define this not because we need to
  57 ;;; manipulate target package objects on the cross-compilation host,
  58 ;;; but only because its MAKE-LOAD-FORM function needs to be hooked
  59 ;;; into the pre-CLOS DEF!STRUCT MAKE-LOAD-FORM system so that we can
  60 ;;; compile things like IN-PACKAGE in warm init before CLOS is set up.
  61 ;;; The DEF!STRUCT side effect of defining a new PACKAGE type on the
  62 ;;; cross-compilation host is just a nuisance, and in order to avoid
  63 ;;; breaking the cross-compilation host, we need to work around it
  64 ;;; around by putting the new PACKAGE type (and the PACKAGEP predicate
  65 ;;; too..) into SB!XC. -- WHN 20000309
  66 (def!struct (sb!xc:package
  67              (:constructor internal-make-package)
  68              (:make-load-form-fun (lambda (p)
  69                                     (values `(find-undeleted-package-or-lose
  70                                               ',(package-name p))
  71                                             nil)))
  72              (:predicate sb!xc:packagep))
  73   #!+sb-doc
  74   "the standard structure for the description of a package"
  75   ;; the name of the package, or NIL for a deleted package
  76   (%name nil :type (or simple-string null))
  77   ;; nickname strings
  78   (%nicknames () :type list)
  79   ;; packages used by this package
  80   (%use-list () :type list)
  81   ;; a list of all the hashtables for inherited symbols. This is
  82   ;; derived from %USE-LIST, but maintained separately from %USE-LIST
  83   ;; for some reason. (Perhaps the reason is that when FIND-SYMBOL*
  84   ;; hits an inherited symbol, it pulls it to the head of the list.)
  85   ;;
  86   ;; FIXME: This needs a more-descriptive name
  87   ;; (USED-PACKAGE-HASH-TABLES?). It also needs an explanation of why
  88   ;; the last entry is NIL. Perhaps it should even just go away and
  89   ;; let us do indirection on the fly through %USE-LIST. (If so,
  90   ;; benchmark to make sure that performance doesn't get stomped..)
  91   ;; (If benchmark performance is important, this should prob'ly
  92   ;; become a vector instead of a list.)
  93   (tables (list nil) :type list)
  94   ;; packages that use this package
  95   (%used-by-list () :type list)
  96   ;; PACKAGE-HASHTABLEs of internal & external symbols
  97   (internal-symbols (missing-arg) :type package-hashtable)
  98   (external-symbols (missing-arg) :type package-hashtable)
  99   ;; shadowing symbols
 100   (%shadowing-symbols () :type list)
 101   ;; documentation string for this package
 102   (doc-string nil :type (or simple-string null))
 103   ;; package locking
 104   #!+sb-package-locks
 105   (lock nil :type boolean)
 106   #!+sb-package-locks
 107   (%implementation-packages nil :type list)
 108   ;; Definition source location
 109   (source-location nil :type (or null sb!c:definition-source-location)))
 110 \f
 111 ;;;; iteration macros
 112
 113 (defmacro-mundanely do-symbols ((var &optional
 114                                      (package '*package*)
 115                                      result-form)
 116                                 &body body-decls)
 117   #!+sb-doc
 118   "DO-SYMBOLS (VAR [PACKAGE [RESULT-FORM]]) {DECLARATION}* {TAG | FORM}*
 119    Executes the FORMs at least once for each symbol accessible in the given
 120    PACKAGE with VAR bound to the current symbol."
 121   (multiple-value-bind (body decls)
 122       (parse-body body-decls :doc-string-allowed nil)
 123     (let ((flet-name (gensym "DO-SYMBOLS-")))
 124       `(block nil
 125          (flet ((,flet-name (,var)
 126                   ,@decls
 127                   (tagbody ,@body)))
 128            (let* ((package (find-undeleted-package-or-lose ,package))
 129                   (shadows (package-%shadowing-symbols package)))
 130              (flet ((iterate-over-hash-table (table ignore)
 131                       (let ((hash-vec (package-hashtable-hash table))
 132                             (sym-vec (package-hashtable-table table)))
 133                         (dotimes (i (length sym-vec))
 134                           (when (>= (aref hash-vec i) 2)
 135                             (let ((sym (aref sym-vec i)))
 136                               (declare (inline member))
 137                               (unless (member sym ignore :test #'string=)
 138                                 (,flet-name sym))))))))
 139                (iterate-over-hash-table (package-internal-symbols package) nil)
 140                (iterate-over-hash-table (package-external-symbols package) nil)
 141                (dolist (use (package-%use-list package))
 142                  (iterate-over-hash-table (package-external-symbols use)
 143                                           shadows)))))
 144          (let ((,var nil))
 145            (declare (ignorable ,var))
 146            ,@decls
 147            ,result-form)))))
 148
 149 (defmacro-mundanely do-external-symbols ((var &optional
 150                                               (package '*package*)
 151                                               result-form)
 152                                          &body body-decls)
 153   #!+sb-doc
 154   "DO-EXTERNAL-SYMBOLS (VAR [PACKAGE [RESULT-FORM]]) {DECL}* {TAG | FORM}*
 155    Executes the FORMs once for each external symbol in the given PACKAGE with
 156    VAR bound to the current symbol."
 157   (multiple-value-bind (body decls)
 158       (parse-body body-decls :doc-string-allowed nil)
 159     (let ((flet-name (gensym "DO-SYMBOLS-")))
 160       `(block nil
 161          (flet ((,flet-name (,var)
 162                   ,@decls
 163                   (tagbody ,@body)))
 164            (let* ((package (find-undeleted-package-or-lose ,package))
 165                   (table (package-external-symbols package))
 166                   (hash-vec (package-hashtable-hash table))
 167                   (sym-vec (package-hashtable-table table)))
 168              (dotimes (i (length sym-vec))
 169                (when (>= (aref hash-vec i) 2)
 170                  (,flet-name (aref sym-vec i))))))
 171          (let ((,var nil))
 172            (declare (ignorable ,var))
 173            ,@decls
 174            ,result-form)))))
 175
 176 (defmacro-mundanely do-all-symbols ((var &optional
 177                                          result-form)
 178                                     &body body-decls)
 179   #!+sb-doc
 180   "DO-ALL-SYMBOLS (VAR [RESULT-FORM]) {DECLARATION}* {TAG | FORM}*
 181    Executes the FORMs once for each symbol in every package with VAR bound
 182    to the current symbol."
 183   (multiple-value-bind (body decls)
 184       (parse-body body-decls :doc-string-allowed nil)
 185     (let ((flet-name (gensym "DO-SYMBOLS-")))
 186       `(block nil
 187          (flet ((,flet-name (,var)
 188                   ,@decls
 189                   (tagbody ,@body)))
 190            (dolist (package (list-all-packages))
 191              (flet ((iterate-over-hash-table (table)
 192                       (let ((hash-vec (package-hashtable-hash table))
 193                             (sym-vec (package-hashtable-table table)))
 194                         (dotimes (i (length sym-vec))
 195                           (when (>= (aref hash-vec i) 2)
 196                             (,flet-name (aref sym-vec i)))))))
 197                (iterate-over-hash-table (package-internal-symbols package))
 198                (iterate-over-hash-table (package-external-symbols package)))))
 199          (let ((,var nil))
 200            (declare (ignorable ,var))
 201            ,@decls
 202            ,result-form)))))
 203 \f
 204 ;;;; WITH-PACKAGE-ITERATOR
 205
 206 (defmacro-mundanely with-package-iterator ((mname package-list
 207                                                   &rest symbol-types)
 208                                            &body body)
 209   #!+sb-doc
 210   "Within the lexical scope of the body forms, MNAME is defined via macrolet
 211    such that successive invocations of (MNAME) will return the symbols,
 212    one by one, from the packages in PACKAGE-LIST. SYMBOL-TYPES may be
 213    any of :INHERITED :EXTERNAL :INTERNAL."
 214   (let* ((packages (gensym))
 215          (these-packages (gensym))
 216          (ordered-types (let ((res nil))
 217                           (dolist (kind '(:inherited :external :internal)
 218                                         res)
 219                             (when (member kind symbol-types)
 220                               (push kind res)))))  ; Order SYMBOL-TYPES.
 221          (counter (gensym))
 222          (kind (gensym))
 223          (hash-vector (gensym))
 224          (vector (gensym))
 225          (package-use-list (gensym))
 226          (init-macro (gensym))
 227          (end-test-macro (gensym))
 228          (real-symbol-p (gensym))
 229          (inherited-symbol-p (gensym))
 230          (BLOCK (gensym)))
 231     `(let* ((,these-packages ,package-list)
 232             (,packages `,(mapcar (lambda (package)
 233                                    (if (packagep package)
 234                                        package
 235                                        ;; Maybe FIND-PACKAGE-OR-DIE?
 236                                        (or (find-package package)
 237                                            (error 'simple-package-error
 238                                                   ;; could be a character
 239                                                   :package (string package)
 240                                                   :format-control "~@<~S does not name a package ~:>"
 241                                                   :format-arguments (list package)))))
 242                                  (if (consp ,these-packages)
 243                                      ,these-packages
 244                                      (list ,these-packages))))
 245             (,counter nil)
 246             (,kind (car ,packages))
 247             (,hash-vector nil)
 248             (,vector nil)
 249             (,package-use-list nil))
 250        ,(if (member :inherited ordered-types)
 251             `(setf ,package-use-list (package-%use-list (car ,packages)))
 252             `(declare (ignore ,package-use-list)))
 253        (macrolet ((,init-macro (next-kind)
 254          (declare (optimize (inhibit-warnings 3)))
 255          (let ((symbols (gensym)))
 256            `(progn
 257               (setf ,',kind ,next-kind)
 258               (setf ,',counter nil)
 259               ,(case next-kind
 260                  (:internal
 261                   `(let ((,symbols (package-internal-symbols
 262                                     (car ,',packages))))
 263                      (when ,symbols
 264                        (setf ,',vector (package-hashtable-table ,symbols))
 265                        (setf ,',hash-vector
 266                              (package-hashtable-hash ,symbols)))))
 267                  (:external
 268                   `(let ((,symbols (package-external-symbols
 269                                     (car ,',packages))))
 270                      (when ,symbols
 271                        (setf ,',vector (package-hashtable-table ,symbols))
 272                        (setf ,',hash-vector
 273                              (package-hashtable-hash ,symbols)))))
 274                  (:inherited
 275                   `(let ((,symbols (and ,',package-use-list
 276                                         (package-external-symbols
 277                                          (car ,',package-use-list)))))
 278                      (when ,symbols
 279                        (setf ,',vector (package-hashtable-table ,symbols))
 280                        (setf ,',hash-vector
 281                              (package-hashtable-hash ,symbols)))))))))
 282                   (,end-test-macro (this-kind)
 283                      `,(let ((next-kind (cadr (member this-kind
 284                                                       ',ordered-types))))
 285                          (if next-kind
 286                              `(,',init-macro ,next-kind)
 287                              `(if (endp (setf ,',packages (cdr ,',packages)))
 288                                   (return-from ,',BLOCK)
 289                                   (,',init-macro ,(car ',ordered-types)))))))
 290          (when ,packages
 291            ,(when (null symbol-types)
 292               (error 'simple-program-error
 293                      :format-control
 294                      "At least one of :INTERNAL, :EXTERNAL, or ~
 295                       :INHERITED must be supplied."))
 296            ,(dolist (symbol symbol-types)
 297               (unless (member symbol '(:internal :external :inherited))
 298                 (error 'program-error
 299                        :format-control
 300                        "~S is not one of :INTERNAL, :EXTERNAL, or :INHERITED."
 301                        :format-argument symbol)))
 302            (,init-macro ,(car ordered-types))
 303            (flet ((,real-symbol-p (number)
 304                     (> number 1)))
 305              (macrolet ((,mname ()
 306               (declare (optimize (inhibit-warnings 3)))
 307               `(block ,',BLOCK
 308                  (loop
 309                    (case ,',kind
 310                      ,@(when (member :internal ',ordered-types)
 311                          `((:internal
 312                             (setf ,',counter
 313                                   (position-if #',',real-symbol-p
 314                                                (the hash-vector ,',hash-vector)
 315                                                :start (if ,',counter
 316                                                           (1+ ,',counter)
 317                                                           0)))
 318                             (if ,',counter
 319                                 (return-from ,',BLOCK
 320                                  (values t (svref ,',vector ,',counter)
 321                                          ,',kind (car ,',packages)))
 322                                 (,',end-test-macro :internal)))))
 323                      ,@(when (member :external ',ordered-types)
 324                          `((:external
 325                             (setf ,',counter
 326                                   (position-if #',',real-symbol-p
 327                                                (the hash-vector ,',hash-vector)
 328                                                :start (if ,',counter
 329                                                           (1+ ,',counter)
 330                                                           0)))
 331                             (if ,',counter
 332                                 (return-from ,',BLOCK
 333                                  (values t (svref ,',vector ,',counter)
 334                                          ,',kind (car ,',packages)))
 335                                 (,',end-test-macro :external)))))
 336                      ,@(when (member :inherited ',ordered-types)
 337                          `((:inherited
 338                             (flet ((,',inherited-symbol-p (number)
 339                                      (when (,',real-symbol-p number)
 340                                        (let* ((p (position
 341                                                   number
 342                                                   (the hash-vector
 343                                                     ,',hash-vector)
 344                                                   :start (if ,',counter
 345                                                              (1+ ,',counter)
 346                                                              0)))
 347                                               (s (svref ,',vector p)))
 348                                          (eql (nth-value
 349                                                1 (find-symbol
 350                                                   (symbol-name s)
 351                                                   (car ,',packages)))
 352                                               :inherited)))))
 353                               (setf ,',counter
 354                                     (when ,',hash-vector
 355                                       (position-if #',',inherited-symbol-p
 356                                                    (the hash-vector
 357                                                      ,',hash-vector)
 358                                                    :start (if ,',counter
 359                                                               (1+ ,',counter)
 360                                                               0)))))
 361                             (cond (,',counter
 362                                    (return-from
 363                                     ,',BLOCK
 364                                     (values t (svref ,',vector ,',counter)
 365                                             ,',kind (car ,',packages))
 366                                     ))
 367                                   (t
 368                                    (setf ,',package-use-list
 369                                          (cdr ,',package-use-list))
 370                                    (cond ((endp ,',package-use-list)
 371                                           (setf ,',packages (cdr ,',packages))
 372                                           (when (endp ,',packages)
 373                                             (return-from ,',BLOCK))
 374                                           (setf ,',package-use-list
 375                                                 (package-%use-list
 376                                                  (car ,',packages)))
 377                                           (,',init-macro ,(car
 378                                                            ',ordered-types)))
 379                                          (t (,',init-macro :inherited)
 380                                             (setf ,',counter nil)))))))))))))
 381                ,@body)))))))