chiark - git - mdw - sod/blob - src/module-parse.lisp

   1 ;;; -*-lisp-*-
   2 ;;;
   3 ;;; Top-level parser for module syntax
   4 ;;;
   5 ;;; (c) 2010 Straylight/Edgeware
   6 ;;;
   7
   8 ;;;----- Licensing notice ---------------------------------------------------
   9 ;;;
  10 ;;; This file is part of the Sensble Object Design, an object system for C.
  11 ;;;
  12 ;;; SOD is free software; you can redistribute it and/or modify
  13 ;;; it under the terms of the GNU General Public License as published by
  14 ;;; the Free Software Foundation; either version 2 of the License, or
  15 ;;; (at your option) any later version.
  16 ;;;
  17 ;;; SOD is distributed in the hope that it will be useful,
  18 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;;; GNU General Public License for more details.
  21 ;;;
  22 ;;; You should have received a copy of the GNU General Public License
  23 ;;; along with SOD; if not, write to the Free Software Foundation,
  24 ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 (in-package #:sod)
  27
  28 ;;;--------------------------------------------------------------------------
  29 ;;; Toplevel syntax.
  30
  31 (export 'module)
  32
  33 ;;; Type names.
  34
  35 (define-pluggable-parser module typename (scanner)
  36   ;; `typename' ID ( `,' ID )* `;'
  37
  38   (with-parser-context (token-scanner-context :scanner scanner)
  39     (parse (and "typename"
  40                 (skip-many (:min 1)
  41                   (seq ((id :id))
  42                     (if (gethash id *module-type-map*)
  43                         (cerror* "Type `~A' already defined" id)
  44                         (add-to-module *module*
  45                                        (make-instance 'type-item
  46                                                       :name id))))
  47                   #\,)
  48                 #\;))))
  49
  50 ;;; Fragments.
  51
  52 (define-pluggable-parser module code (scanner)
  53   ;; `code' ID `:' ID [ CONSTRAINTS ] `{' C-FRAGMENT `}'
  54
  55   (with-parser-context (token-scanner-context :scanner scanner)
  56     (parse (seq ("code"
  57                  (reason :id)
  58                  #\:
  59                  (name :id)
  60                  (constraints (? (seq (#\[
  61                                        (constraints (list (:min 1)
  62                                                       (list (:min 1) :id)
  63                                                       #\,))
  64                                        #\])
  65                                    constraints)))
  66                  (fragment (parse-delimited-fragment scanner #\{ #\})))
  67              (add-to-module *module* (make-instance 'code-fragment-item
  68                                                     :fragment fragment
  69                                                     :constraints constraints
  70                                                     :reason reason
  71                                                     :name name))))))
  72
  73 ;;; External files.
  74
  75 (defun read-module (pathname &key (truename (truename pathname)) location)
  76   "Parse the file at PATHNAME as a module, returning it.
  77
  78    This is the main entry point for parsing module files.  You may well know
  79    the file's TRUENAME already (e.g., because `probe-file' dropped it into
  80    your lap) so you can avoid repeating the search by providing it.
  81
  82    The LOCATION is the thing which wanted the module imported -- usually a
  83    `file-location' object, though it might be anything other than `t' which
  84    can be printed in the event of circular imports."
  85
  86   (define-module (pathname :location location :truename truename)
  87     (with-open-file (f-stream pathname :direction :input)
  88       (let* ((*readtable* (copy-readtable))
  89              (char-scanner (make-instance 'charbuf-scanner
  90                                           :stream f-stream))
  91              (scanner (make-instance 'sod-token-scanner
  92                                      :char-scanner char-scanner)))
  93         (with-default-error-location (scanner)
  94           (with-parser-context (token-scanner-context :scanner scanner)
  95             (parse (skip-many () (plug module scanner)))))))))
  96
  97 (define-pluggable-parser module test (scanner)
  98   ;; `demo' STRING `;'
  99
 100   (with-parser-context (token-scanner-context :scanner scanner)
 101     (parse (seq ("demo" (string :string) #\;)
 102              (format t ";; DEMO ~S~%" string)))))
 103
 104 (define-pluggable-parser module file (scanner)
 105   ;; `import' STRING `;'
 106   ;; `load' STRING `;'
 107
 108   (flet ((common (name type what thunk)
 109            (find-file scanner
 110                       (merge-pathnames name
 111                                        (make-pathname :type type
 112                                                       :case :common))
 113                       what
 114                       thunk)))
 115     (with-parser-context (token-scanner-context :scanner scanner)
 116       (parse (or (seq ("import" (name :string) #\;)
 117                    (common name "SOD" "module"
 118                            (lambda (path true)
 119                              (handler-case
 120                                  (let ((module (read-module path
 121                                                             :truename true)))
 122                                    (when module
 123                                      (module-import module)
 124                                      (pushnew module
 125                                               (module-dependencies
 126                                                *module*))))
 127                                (file-error (error)
 128                                  (cerror* "Error reading module ~S: ~A"
 129                                           path error))))))
 130                  (seq ("load" (name :string) #\;)
 131                    (common name "LISP" "Lisp file"
 132                            (lambda (path true)
 133                              (handler-case
 134                                  (load true :verbose nil :print nil)
 135                                (error (error)
 136                                  (cerror* "Error loading Lisp file ~S: ~A"
 137                                           path error)))))))))))
 138
 139 ;;; Lisp escape.
 140
 141 (define-pluggable-parser module lisp (scanner)
 142   ;; `lisp' s-expression `;'
 143
 144   (with-parser-context (token-scanner-context :scanner scanner)
 145     (parse (seq ((sexp (if (and (eql (token-type scanner) :id)
 146                                 (string= (token-value scanner) "lisp"))
 147                            (let* ((stream (make-scanner-stream scanner))
 148                                   (sexp (read stream t)))
 149                              (scanner-step scanner)
 150                              (values sexp t t))
 151                            (values '((:id "lisp")) nil nil)))
 152                  #\;)
 153              (eval sexp)))))
 154
 155 ;;;--------------------------------------------------------------------------
 156 ;;; Class declarations.
 157
 158 (defun parse-class-body (scaner pset name supers)
 159   ;; class-body ::= `{' class-item* `}'
 160   (with-parser-context (token-scanner-context :scanner scanner)
 161     (make-class-type name)
 162     (let* ((class (make-sod-class name (mapcat #'find-sod-class supers)
 163                                   pset scanner))
 164            (nick (sod-class-nickname class)))
 165
 166       (labels ((parse-maybe-dotted-declarator (base-type)
 167                  ;; Parse a declarator or dotted-declarator, i.e., one whose
 168                  ;; centre is
 169                  ;;
 170                  ;; maybe-dotted-identifier ::= [id `.'] id
 171                  ;;
 172                  ;; A plain identifier is returned as a string, as usual; a
 173                  ;; dotted identifier is returned as a cons cell of the two
 174                  ;; names.
 175                  (parse-declarator
 176                   scanner base-type
 177                   :centre (parser ()
 178                             (seq ((name-a :id)
 179                                   (name-b (? (seq (#\. (id :id)) id))))
 180                               (if name-b (cons name-a name-b)
 181                                   name-a)))))
 182
 183                ;; class-item ::= [property-set] raw-class-item
 184                ;;
 185
 186                (parse-message-item (sub-pset type name)
 187                  ;; message-item ::=
 188                  ;;     declspec+ declarator -!- (method-body | `;')
 189                  (make-sod-message class name type sub-pset scanner)
 190                  (parse (or #\; (parse-method-item nil type nick name))))
 191
 192                (parse-method-item (sub-pset type sub-nick name)
 193                  ;; method-item ::=
 194                  ;;     declspec+ dotted-declarator -!- method-body
 195                  ;;
 196                  ;; method-body ::= `{' c-fragment `}' | `extern' `;'
 197                  (parse (seq ((body (or (seq ("extern" #\;) nil)
 198                                         (parse-delimited-fragment
 199                                          scanner #\{ #\}))))
 200                           (make-sod-method class sub-nick name type
 201                                            body sub-pset scanner))))
 202
 203                (parse-initializer ()
 204                  ;; initializer ::= `=' c-fragment | `=' `{' c-fragment `}'
 205                  ;;
 206                  ;; Return (VALUE-KIND . VALUE-FORM), ready for passing to a
 207                  ;; `sod-initializer' constructor.
 208                  (parse (or (peek (seq (#\= (frag (parse-delimited-fragment
 209                                                    scanner #\{ #\})))
 210                                     (cons :compound frag)))
 211                             (seq ((frag (parse-delimited-fragment
 212                                          scanner #\= '(#\; #\,)
 213                                          :keep-end t)))
 214                               (cons :simple frag)))))
 215
 216                (parse-slot-item (sub-pset base-type type name)
 217                  ;; slot-item ::=
 218                  ;;     declspec+ declarator -!- [initializer]
 219                  ;;             [`,' init-declarator-list] `;'
 220                  ;;
 221                  ;; init-declarator-list ::=
 222                  ;;     declarator [initializer] [`,' init-declarator-list]
 223                  (parse (and (seq ((init (? (parse-initializer))))
 224                                (make-sod-slot class name type
 225                                               sub-pset scanner)
 226                                (when init
 227                                  (make-sod-instance-initializer
 228                                   class nick name (car init) (cdr init)
 229                                   nil scanner)))
 230                              (skip-many ()
 231                                (seq (#\,
 232                                      (ds (parse-declarator scanner
 233                                                            base-type))
 234                                      (init (? (parse-initializer))))
 235                                  (make-sod-slot class (cdr ds) (car ds)
 236                                                 sub-pset scanner)
 237                                  (when init
 238                                    (make-sod-instance-initializer
 239                                     class nick (cdr ds)
 240                                     (car init) (cdr init)
 241                                     nil scanner))))
 242                              #\;)))
 243
 244                (parse-initializer-item (sub-pset constructor)
 245                  ;; initializer-item ::=
 246                  ;;     [`class'] -!- slot-initializer-list `;'
 247                  ;;
 248                  ;; slot-initializer ::= id `.' id initializer
 249                  (parse (and (skip-many ()
 250                                (seq ((name-a :id) #\. (name-b :id)
 251                                      (init (parse-initializer)))
 252                                  (funcall constructor class
 253                                           name-a name-b
 254                                           (car init) (cdr init)
 255                                           sub-pset scanner))
 256                                #\,)
 257                              #\;)))
 258
 259                (class-item-dispatch (sub-pset base-type type name)
 260                  ;; Logically part of `parse-raw-class-item', but the
 261                  ;; indentation was getting crazy.  We're currently at
 262                  ;;
 263                  ;; raw-class-item ::=
 264                  ;;     declspec+ (declarator | dotted-declarator) -!- ...
 265                  ;;   | other-items
 266                  ;;
 267                  ;; If the declarator is dotted then this must be a method
 268                  ;; definition; otherwise it might be a message or slot.
 269                  (cond ((not (typep type 'c-function-type))
 270                         (when (consp name)
 271                           (cerror*-with-location
 272                            scanner
 273                            "Method declarations must have function type.")
 274                           (setf name (cdr name)))
 275                         (parse-slot-item sub-pset base-type type name))
 276                        ((consp name)
 277                         (parse-method-item sub-pset type
 278                                            (car name) (cdr name)))
 279                        (t
 280                         (parse-message-item sub-pset type name))))
 281
 282                (parse-raw-class-item (sub-pset)
 283                  ;; raw-class-item ::=
 284                  ;;     message-item
 285                  ;;   | method-item
 286                  ;;   | slot-item
 287                  ;;   | initializer-item
 288                  ;;
 289                  ;; Most of the above begin with declspecs and a declarator
 290                  ;; (which might be dotted).  So we parse that here and
 291                  ;; dispatch based on what we find.
 292                  (parse (or (peek
 293                              (seq ((ds (parse-c-type scanner))
 294                                    (dc (parse-maybe-dotted-declarator ds))
 295                                    (result (class-item-dispatch sub-pset
 296                                                                 ds
 297                                                                 (car dc)
 298                                                                 (cdr dc))))
 299                                result))
 300                             (and "class"
 301                                  (parse-initializer-item
 302                                   sub-pset
 303                                   #'make-sod-class-initializer))
 304                             (parse-initializer-item
 305                              sub-pset
 306                              #'make-sod-instance-initializer)))))
 307
 308         (parse (and #\{
 309                     (skip-many ()
 310                       (seq ((sub-pset (? (parse-property-set)))
 311                             (nil (parse-raw-class-item sub-pset)))))
 312                     #\}))))))
 313
 314 (define-pluggable-parser module class (scanner)
 315   ;; `class' id [`:' id-list] class-body
 316   ;; `class' id `;'
 317
 318   (with-parser-context (token-scanner-context :scanner scanner)
 319     (parse (seq ("class"
 320                  (name :id)
 321                  (nil (or (seq (#\;)
 322                             (make-class-type name))
 323                           (seq ((supers (? (seq (#\: (ids (list () :id #\,)))
 324                                              ids)))
 325                                 (nil (parse-class-body
 326                                       scanner
 327                                       pset name supers)))))))))))
 328
 329
 330
 331
 332     (parse (seq ("class"
 333                  (name :id)
 334                  (supers (? (seq (#\: (supers (list (:min 1) :id #\,)))
 335                                  supers)))
 336                  #\{
 337
 338
 339 ;;;----- That's all, folks --------------------------------------------------