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 (sb!xc:deftype hash-vector () '(simple-array (unsigned-byte 8) (*)))
  34
  35 (sb!xc:defstruct (package-hashtable (:constructor %make-package-hashtable ())
  36                                     (:copier nil))
  37   ;; The g-vector of symbols.
  38   ;; FIXME: could just be type SIMPLE-VECTOR, with (MISSING-ARG) default
  39   (table nil :type (or simple-vector null))
  40   ;; The i-vector of pname hash values.
  41   ;; FIXME: could just be type HASH-VECTOR, with (MISSING-ARG) default
  42   (hash nil :type (or hash-vector null))
  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 0 :type index)
  49   ;; The remaining number of entries that can be made before we have to rehash.
  50   (free 0 :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 \f
 104 ;;;; iteration macros
 105
 106 (defmacro-mundanely do-symbols ((var &optional
 107                                      (package '*package*)
 108                                      result-form)
 109                                 &body body-decls)
 110   #!+sb-doc
 111   "DO-SYMBOLS (VAR [PACKAGE [RESULT-FORM]]) {DECLARATION}* {TAG | FORM}*
 112    Executes the FORMs at least once for each symbol accessible in the given
 113    PACKAGE with VAR bound to the current symbol."
 114   (multiple-value-bind (body decls) body-decls
 115     (let ((flet-name (gensym "DO-SYMBOLS-")))
 116       `(block nil
 117          (flet ((,flet-name (,var)
 118                   ,@decls
 119                   (tagbody ,@body)))
 120            (let* ((package (find-undeleted-package-or-lose ,package))
 121                   (shadows (package-%shadowing-symbols package)))
 122              (flet ((iterate-over-hash-table (table ignore)
 123                       (let ((hash-vec (package-hashtable-hash table))
 124                             (sym-vec (package-hashtable-table table)))
 125                         (declare (type (simple-array (unsigned-byte 8) (*))
 126                                        hash-vec)
 127                                  (type simple-vector sym-vec))
 128                         (dotimes (i (length sym-vec))
 129                           (when (>= (aref hash-vec i) 2)
 130                             (let ((sym (aref sym-vec i)))
 131                               (declare (inline member))
 132                               (unless (member sym ignore :test #'string=)
 133                                 (,flet-name sym))))))))
 134                (iterate-over-hash-table (package-internal-symbols package) nil)
 135                (iterate-over-hash-table (package-external-symbols package) nil)
 136                (dolist (use (package-%use-list package))
 137                  (iterate-over-hash-table (package-external-symbols use)
 138                                           shadows)))))
 139          (let ((,var nil))
 140            (declare (ignorable ,var))
 141            ,@decls
 142            ,result-form)))))
 143
 144 (defmacro-mundanely do-external-symbols ((var &optional
 145                                               (package '*package*)
 146                                               result-form)
 147                                          &body body-decls)
 148   #!+sb-doc
 149   "DO-EXTERNAL-SYMBOLS (VAR [PACKAGE [RESULT-FORM]]) {DECL}* {TAG | FORM}*
 150    Executes the FORMs once for each external symbol in the given PACKAGE with
 151    VAR bound to the current symbol."
 152   (multiple-value-bind (body decls) (parse-body body-decls nil)
 153     (let ((flet-name (gensym "DO-SYMBOLS-")))
 154       `(block nil
 155          (flet ((,flet-name (,var)
 156                   ,@decls
 157                   (tagbody ,@body)))
 158            (let* ((package (find-undeleted-package-or-lose ,package))
 159                   (table (package-external-symbols package))
 160                   (hash-vec (package-hashtable-hash table))
 161                   (sym-vec (package-hashtable-table table)))
 162              (declare (type (simple-array (unsigned-byte 8) (*))
 163                             hash-vec)
 164                       (type simple-vector sym-vec))
 165              (dotimes (i (length sym-vec))
 166                (when (>= (aref hash-vec i) 2)
 167                  (,flet-name (aref sym-vec i))))))
 168          (let ((,var nil))
 169            (declare (ignorable ,var))
 170            ,@decls
 171            ,result-form)))))
 172
 173 (defmacro-mundanely do-all-symbols ((var &optional
 174                                          result-form)
 175                                     &body body-decls)
 176   #!+sb-doc
 177   "DO-ALL-SYMBOLS (VAR [RESULT-FORM]) {DECLARATION}* {TAG | FORM}*
 178    Executes the FORMs once for each symbol in every package with VAR bound
 179    to the current symbol."
 180   (multiple-value-bind (body decls) (parse-body body-decls nil)
 181     (let ((flet-name (gensym "DO-SYMBOLS-")))
 182       `(block nil
 183          (flet ((,flet-name (,var)
 184                   ,@decls
 185                   (tagbody ,@body)))
 186            (dolist (package (list-all-packages))
 187              (flet ((iterate-over-hash-table (table)
 188                       (let ((hash-vec (package-hashtable-hash table))
 189                             (sym-vec (package-hashtable-table table)))
 190                         (declare (type (simple-array (unsigned-byte 8) (*))
 191                                        hash-vec)
 192                                  (type simple-vector sym-vec))
 193                         (dotimes (i (length sym-vec))
 194                           (when (>= (aref hash-vec i) 2)
 195                             (,flet-name (aref sym-vec i)))))))
 196                (iterate-over-hash-table (package-internal-symbols package))
 197                (iterate-over-hash-table (package-external-symbols package)))))
 198          (let ((,var nil))
 199            (declare (ignorable ,var))
 200            ,@decls
 201            ,result-form)))))
 202 \f
 203 ;;;; WITH-PACKAGE-ITERATOR
 204
 205 (defmacro-mundanely with-package-iterator ((mname package-list
 206                                                   &rest symbol-types)
 207                                            &body body)
 208   #!+sb-doc
 209   "Within the lexical scope of the body forms, MNAME is defined via macrolet
 210    such that successive invocations of (MNAME) will return the symbols,
 211    one by one, from the packages in PACKAGE-LIST. SYMBOL-TYPES may be
 212    any of :INHERITED :EXTERNAL :INTERNAL."
 213   (let* ((packages (gensym))
 214          (these-packages (gensym))
 215          (ordered-types (let ((res nil))
 216                           (dolist (kind '(:inherited :external :internal)
 217                                         res)
 218                             (when (member kind symbol-types)
 219                               (push kind res)))))  ; Order SYMBOL-TYPES.
 220          (counter (gensym))
 221          (kind (gensym))
 222          (hash-vector (gensym))
 223          (vector (gensym))
 224          (package-use-list (gensym))
 225          (init-macro (gensym))
 226          (end-test-macro (gensym))
 227          (real-symbol-p (gensym))
 228          (inherited-symbol-p (gensym))
 229          (BLOCK (gensym)))
 230     `(let* ((,these-packages ,package-list)
 231             (,packages `,(mapcar (lambda (package)
 232                                    (if (packagep package)
 233                                        package
 234                                        (find-package package)))
 235                                  (if (consp ,these-packages)
 236                                      ,these-packages
 237                                      (list ,these-packages))))
 238             (,counter nil)
 239             (,kind (car ,packages))
 240             (,hash-vector nil)
 241             (,vector nil)
 242             (,package-use-list nil))
 243        ,(if (member :inherited ordered-types)
 244             `(setf ,package-use-list (package-%use-list (car ,packages)))
 245             `(declare (ignore ,package-use-list)))
 246        (macrolet ((,init-macro (next-kind)
 247          (let ((symbols (gensym)))
 248            `(progn
 249               (setf ,',kind ,next-kind)
 250               (setf ,',counter nil)
 251               ,(case next-kind
 252                  (:internal
 253                   `(let ((,symbols (package-internal-symbols
 254                                     (car ,',packages))))
 255                      (when ,symbols
 256                        (setf ,',vector (package-hashtable-table ,symbols))
 257                        (setf ,',hash-vector
 258                              (package-hashtable-hash ,symbols)))))
 259                  (:external
 260                   `(let ((,symbols (package-external-symbols
 261                                     (car ,',packages))))
 262                      (when ,symbols
 263                        (setf ,',vector (package-hashtable-table ,symbols))
 264                        (setf ,',hash-vector
 265                              (package-hashtable-hash ,symbols)))))
 266                  (:inherited
 267                   `(let ((,symbols (and ,',package-use-list
 268                                         (package-external-symbols
 269                                          (car ,',package-use-list)))))
 270                      (when ,symbols
 271                        (setf ,',vector (package-hashtable-table ,symbols))
 272                        (setf ,',hash-vector
 273                              (package-hashtable-hash ,symbols)))))))))
 274                   (,end-test-macro (this-kind)
 275                      `,(let ((next-kind (cadr (member this-kind
 276                                                       ',ordered-types))))
 277                          (if next-kind
 278                              `(,',init-macro ,next-kind)
 279                              `(if (endp (setf ,',packages (cdr ,',packages)))
 280                                   (return-from ,',BLOCK)
 281                                   (,',init-macro ,(car ',ordered-types)))))))
 282          (when ,packages
 283            ,(when (null symbol-types)
 284               (error 'simple-program-error
 285                      :format-control
 286                      "At least one of :INTERNAL, :EXTERNAL, or ~
 287                       :INHERITED must be supplied."))
 288            ,(dolist (symbol symbol-types)
 289               (unless (member symbol '(:internal :external :inherited))
 290                 (error 'program-error
 291                        :format-control
 292                        "~S is not one of :INTERNAL, :EXTERNAL, or :INHERITED."
 293                        :format-argument symbol)))
 294            (,init-macro ,(car ordered-types))
 295            (flet ((,real-symbol-p (number)
 296                     (> number 1)))
 297              (macrolet ((,mname ()
 298               `(block ,',BLOCK
 299                  (loop
 300                    (case ,',kind
 301                      ,@(when (member :internal ',ordered-types)
 302                          `((:internal
 303                             (setf ,',counter
 304                                   (position-if #',',real-symbol-p
 305                                                ,',hash-vector
 306                                                :start (if ,',counter
 307                                                           (1+ ,',counter)
 308                                                           0)))
 309                             (if ,',counter
 310                                 (return-from ,',BLOCK
 311                                  (values t (svref ,',vector ,',counter)
 312                                          ,',kind (car ,',packages)))
 313                                 (,',end-test-macro :internal)))))
 314                      ,@(when (member :external ',ordered-types)
 315                          `((:external
 316                             (setf ,',counter
 317                                   (position-if #',',real-symbol-p
 318                                                ,',hash-vector
 319                                                :start (if ,',counter
 320                                                           (1+ ,',counter)
 321                                                           0)))
 322                             (if ,',counter
 323                                 (return-from ,',BLOCK
 324                                  (values t (svref ,',vector ,',counter)
 325                                          ,',kind (car ,',packages)))
 326                                 (,',end-test-macro :external)))))
 327                      ,@(when (member :inherited ',ordered-types)
 328                          `((:inherited
 329                             (flet ((,',inherited-symbol-p (number)
 330                                      (when (,',real-symbol-p number)
 331                                        (let* ((p (position
 332                                                   number ,',hash-vector
 333                                                   :start (if ,',counter
 334                                                              (1+ ,',counter)
 335                                                              0)))
 336                                               (s (svref ,',vector p)))
 337                                          (eql (nth-value
 338                                                1 (find-symbol
 339                                                   (symbol-name s)
 340                                                   (car ,',packages)))
 341                                               :inherited)))))
 342                               (setf ,',counter
 343                                     (position-if #',',inherited-symbol-p
 344                                                  ,',hash-vector
 345                                                  :start (if ,',counter
 346                                                             (1+ ,',counter)
 347                                                             0))))
 348                             (cond (,',counter
 349                                    (return-from
 350                                     ,',BLOCK
 351                                     (values t (svref ,',vector ,',counter)
 352                                             ,',kind (car ,',packages))
 353                                     ))
 354                                   (t
 355                                    (setf ,',package-use-list
 356                                          (cdr ,',package-use-list))
 357                                    (cond ((endp ,',package-use-list)
 358                                           (setf ,',packages (cdr ,',packages))
 359                                           (when (endp ,',packages)
 360                                             (return-from ,',BLOCK))
 361                                           (setf ,',package-use-list
 362                                                 (package-%use-list
 363                                                  (car ,',packages)))
 364                                           (,',init-macro ,(car
 365                                                            ',ordered-types)))
 366                                          (t (,',init-macro :inherited)
 367                                             (setf ,',counter nil)))))))))))))
 368                ,@body)))))))