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5f4b817d | 1 | ;;; 'SCM' type tag decoding. |
e2fafeb9 | 2 | ;;; Copyright (C) 2014, 2015 Free Software Foundation, Inc. |
5f4b817d LC |
3 | ;;; |
4 | ;;; This library is free software; you can redistribute it and/or modify it | |
5 | ;;; under the terms of the GNU Lesser General Public License as published by | |
6 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
7 | ;;; your option) any later version. | |
8 | ;;; | |
9 | ;;; This library is distributed in the hope that it will be useful, but | |
10 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser | |
12 | ;;; General Public License for more details. | |
13 | ;;; | |
14 | ;;; You should have received a copy of the GNU Lesser General Public License | |
15 | ;;; along with this program. If not, see <http://www.gnu.org/licenses/>. | |
16 | ||
17 | (define-module (system base types) | |
18 | #:use-module (rnrs bytevectors) | |
19 | #:use-module (rnrs io ports) | |
20 | #:use-module (srfi srfi-1) | |
21 | #:use-module (srfi srfi-9) | |
22 | #:use-module (srfi srfi-9 gnu) | |
23 | #:use-module (srfi srfi-11) | |
24 | #:use-module (srfi srfi-26) | |
25 | #:use-module (srfi srfi-60) | |
26 | #:use-module (ice-9 match) | |
27 | #:use-module (ice-9 iconv) | |
28 | #:use-module (ice-9 format) | |
29 | #:use-module (ice-9 vlist) | |
30 | #:use-module (system foreign) | |
31 | #:export (%word-size | |
32 | ||
33 | memory-backend | |
34 | memory-backend? | |
35 | %ffi-memory-backend | |
36 | dereference-word | |
37 | memory-port | |
38 | type-number->name | |
39 | ||
40 | inferior-object? | |
41 | inferior-object-kind | |
42 | inferior-object-sub-kind | |
43 | inferior-object-address | |
44 | ||
45 | inferior-fluid? | |
46 | inferior-fluid-number | |
47 | ||
48 | inferior-struct? | |
49 | inferior-struct-name | |
50 | inferior-struct-fields | |
51 | ||
52 | scm->object)) | |
53 | ||
54 | ;;; Commentary: | |
55 | ;;; | |
56 | ;;; 'SCM' type tag decoding, primarily to support Guile debugging in GDB. | |
57 | ;;; | |
58 | ;;; Code: | |
59 | ||
60 | \f | |
61 | ;;; | |
62 | ;;; Memory back-ends. | |
63 | ;;; | |
64 | ||
65 | (define %word-size | |
66 | ;; The pointer size. | |
67 | (sizeof '*)) | |
68 | ||
69 | (define-record-type <memory-backend> | |
70 | (memory-backend peek open type-name) | |
71 | memory-backend? | |
72 | (peek memory-backend-peek) | |
73 | (open memory-backend-open) | |
74 | (type-name memory-backend-type-name)) ; for SMOBs and ports | |
75 | ||
76 | (define %ffi-memory-backend | |
77 | ;; The FFI back-end to access the current process's memory. The main | |
78 | ;; purpose of this back-end is to allow testing. | |
79 | (let () | |
80 | (define (dereference-word address) | |
81 | (let* ((ptr (make-pointer address)) | |
82 | (bv (pointer->bytevector ptr %word-size))) | |
83 | (bytevector-uint-ref bv 0 (native-endianness) %word-size))) | |
84 | ||
85 | (define (open address size) | |
86 | (define current-address address) | |
87 | ||
88 | (define (read-memory! bv index count) | |
89 | (let* ((ptr (make-pointer current-address)) | |
90 | (mem (pointer->bytevector ptr count))) | |
91 | (bytevector-copy! mem 0 bv index count) | |
92 | (set! current-address (+ current-address count)) | |
93 | count)) | |
94 | ||
95 | (if size | |
96 | (let* ((ptr (make-pointer address)) | |
97 | (bv (pointer->bytevector ptr size))) | |
98 | (open-bytevector-input-port bv)) | |
99 | (let ((port (make-custom-binary-input-port "ffi-memory" | |
100 | read-memory! | |
101 | #f #f #f))) | |
102 | (setvbuf port _IONBF) | |
103 | port))) | |
104 | ||
105 | (memory-backend dereference-word open #f))) | |
106 | ||
107 | (define-inlinable (dereference-word backend address) | |
108 | "Return the word at ADDRESS, using BACKEND." | |
109 | (let ((peek (memory-backend-peek backend))) | |
110 | (peek address))) | |
111 | ||
112 | (define-syntax memory-port | |
113 | (syntax-rules () | |
114 | "Return an input port to the SIZE bytes at ADDRESS, using BACKEND. When | |
115 | SIZE is omitted, return an unbounded port to the memory at ADDRESS." | |
116 | ((_ backend address) | |
117 | (let ((open (memory-backend-open backend))) | |
118 | (open address #f))) | |
119 | ((_ backend address size) | |
120 | (let ((open (memory-backend-open backend))) | |
121 | (open address size))))) | |
122 | ||
123 | (define (get-word port) | |
124 | "Read a word from PORT and return it as an integer." | |
125 | (let ((bv (get-bytevector-n port %word-size))) | |
126 | (bytevector-uint-ref bv 0 (native-endianness) %word-size))) | |
127 | ||
128 | (define-inlinable (type-number->name backend kind number) | |
129 | "Return the name of the type NUMBER of KIND, where KIND is one of | |
130 | 'smob or 'port, or #f if the information is unavailable." | |
131 | (let ((proc (memory-backend-type-name backend))) | |
132 | (and proc (proc kind number)))) | |
133 | ||
134 | \f | |
135 | ;;; | |
136 | ;;; Matching bit patterns and cells. | |
137 | ;;; | |
138 | ||
139 | (define-syntax match-cell-words | |
140 | (syntax-rules (bytevector) | |
141 | ((_ port ((bytevector name len) rest ...) body) | |
142 | (let ((name (get-bytevector-n port len)) | |
143 | (remainder (modulo len %word-size))) | |
144 | (unless (zero? remainder) | |
145 | (get-bytevector-n port (- %word-size remainder))) | |
146 | (match-cell-words port (rest ...) body))) | |
147 | ((_ port (name rest ...) body) | |
148 | (let ((name (get-word port))) | |
149 | (match-cell-words port (rest ...) body))) | |
150 | ((_ port () body) | |
151 | body))) | |
152 | ||
153 | (define-syntax match-bit-pattern | |
154 | (syntax-rules (& || = _) | |
155 | ((match-bit-pattern bits ((a || b) & n = c) consequent alternate) | |
156 | (let ((tag (logand bits n))) | |
157 | (if (= tag c) | |
158 | (let ((b tag) | |
159 | (a (logand bits (bitwise-not n)))) | |
160 | consequent) | |
161 | alternate))) | |
162 | ((match-bit-pattern bits (x & n = c) consequent alternate) | |
163 | (let ((tag (logand bits n))) | |
164 | (if (= tag c) | |
165 | (let ((x bits)) | |
166 | consequent) | |
167 | alternate))) | |
168 | ((match-bit-pattern bits (_ & n = c) consequent alternate) | |
169 | (let ((tag (logand bits n))) | |
170 | (if (= tag c) | |
171 | consequent | |
172 | alternate))) | |
173 | ((match-bit-pattern bits ((a << n) || c) consequent alternate) | |
174 | (let ((tag (bitwise-and bits (- (expt 2 n) 1)))) | |
175 | (if (= tag c) | |
176 | (let ((a (arithmetic-shift bits (- n)))) | |
177 | consequent) | |
178 | alternate))))) | |
179 | ||
180 | (define-syntax match-cell-clauses | |
181 | (syntax-rules () | |
182 | ((_ port tag (((tag-pattern thing ...) body) rest ...)) | |
183 | (match-bit-pattern tag tag-pattern | |
184 | (match-cell-words port (thing ...) body) | |
185 | (match-cell-clauses port tag (rest ...)))) | |
186 | ((_ port tag ()) | |
187 | (inferior-object 'unmatched-tag tag)))) | |
188 | ||
189 | (define-syntax match-cell | |
190 | (syntax-rules () | |
191 | "Match a cell---i.e., a non-immediate value other than a pair. The | |
192 | cell's contents are read from PORT." | |
193 | ((_ port (pattern body ...) ...) | |
194 | (let ((port* port) | |
195 | (tag (get-word port))) | |
196 | (match-cell-clauses port* tag | |
197 | ((pattern (begin body ...)) | |
198 | ...)))))) | |
199 | ||
200 | (define-syntax match-scm-clauses | |
201 | (syntax-rules () | |
202 | ((_ bits | |
203 | (bit-pattern body ...) | |
204 | rest ...) | |
205 | (match-bit-pattern bits bit-pattern | |
206 | (begin body ...) | |
207 | (match-scm-clauses bits rest ...))) | |
208 | ((_ bits) | |
209 | 'unmatched-scm))) | |
210 | ||
211 | (define-syntax match-scm | |
212 | (syntax-rules () | |
213 | "Match BITS, an integer representation of an 'SCM' value, against | |
214 | CLAUSES. Each clause must have the form: | |
215 | ||
216 | (PATTERN BODY ...) | |
217 | ||
218 | PATTERN is a bit pattern that may specify bitwise operations on BITS to | |
219 | determine if it matches. TEMPLATE specify the name of the variable to bind | |
220 | the matching bits, possibly with bitwise operations to extract it from BITS." | |
221 | ((_ bits clauses ...) | |
222 | (let ((bits* bits)) | |
223 | (match-scm-clauses bits* clauses ...))))) | |
224 | ||
225 | \f | |
226 | ;;; | |
227 | ;;; Tags---keep in sync with libguile/tags.h! | |
228 | ;;; | |
229 | ||
230 | ;; Immediate values. | |
231 | (define %tc2-int 2) | |
232 | (define %tc3-imm24 4) | |
233 | ||
234 | (define %tc3-cons 0) | |
235 | (define %tc3-int1 %tc2-int) | |
236 | (define %tc3-int2 (+ %tc2-int 4)) | |
237 | ||
238 | (define %tc8-char (+ 8 %tc3-imm24)) | |
239 | (define %tc8-flag (+ %tc3-imm24 0)) | |
240 | ||
241 | ;; Cell types. | |
242 | (define %tc3-struct 1) | |
243 | (define %tc7-symbol 5) | |
577eab81 | 244 | (define %tc7-variable 7) |
5f4b817d | 245 | (define %tc7-vector 13) |
e0da53b4 | 246 | (define %tc7-wvect 15) |
5f4b817d LC |
247 | (define %tc7-string 21) |
248 | (define %tc7-number 23) | |
249 | (define %tc7-hashtable 29) | |
250 | (define %tc7-pointer 31) | |
251 | (define %tc7-fluid 37) | |
252 | (define %tc7-stringbuf 39) | |
253 | (define %tc7-dynamic-state 45) | |
254 | (define %tc7-frame 47) | |
e2fafeb9 | 255 | (define %tc7-keyword 53) |
475772ea | 256 | (define %tc7-program 69) |
5f4b817d LC |
257 | (define %tc7-vm-continuation 71) |
258 | (define %tc7-bytevector 77) | |
475772ea MW |
259 | (define %tc7-weak-set 85) |
260 | (define %tc7-weak-table 87) | |
261 | (define %tc7-array 93) | |
262 | (define %tc7-bitvector 95) | |
5f4b817d LC |
263 | (define %tc7-port 125) |
264 | (define %tc7-smob 127) | |
265 | ||
266 | (define %tc16-bignum (+ %tc7-number (* 1 256))) | |
267 | (define %tc16-real (+ %tc7-number (* 2 256))) | |
268 | (define %tc16-complex (+ %tc7-number (* 3 256))) | |
269 | (define %tc16-fraction (+ %tc7-number (* 4 256))) | |
270 | ||
271 | ||
272 | ;; "Stringbufs". | |
273 | (define-record-type <stringbuf> | |
274 | (stringbuf string) | |
275 | stringbuf? | |
276 | (string stringbuf-contents)) | |
277 | ||
278 | (set-record-type-printer! <stringbuf> | |
279 | (lambda (stringbuf port) | |
280 | (display "#<stringbuf " port) | |
281 | (write (stringbuf-contents stringbuf) port) | |
282 | (display "#>" port))) | |
283 | ||
284 | ;; Structs. | |
285 | (define-record-type <inferior-struct> | |
286 | (inferior-struct name fields) | |
287 | inferior-struct? | |
288 | (name inferior-struct-name) | |
289 | (fields inferior-struct-fields set-inferior-struct-fields!)) | |
290 | ||
291 | (define print-inferior-struct | |
292 | (let ((%printed-struct (make-parameter vlist-null))) | |
293 | (lambda (struct port) | |
294 | (if (vhash-assq struct (%printed-struct)) | |
295 | (format port "#-1#") | |
296 | (begin | |
297 | (format port "#<struct ~a" | |
298 | (inferior-struct-name struct)) | |
299 | (parameterize ((%printed-struct | |
300 | (vhash-consq struct #t (%printed-struct)))) | |
301 | (for-each (lambda (field) | |
302 | (if (eq? field struct) | |
303 | (display " #0#" port) | |
304 | (format port " ~s" field))) | |
305 | (inferior-struct-fields struct))) | |
306 | (format port " ~x>" (object-address struct))))))) | |
307 | ||
308 | (set-record-type-printer! <inferior-struct> print-inferior-struct) | |
309 | ||
310 | ;; Fluids. | |
311 | (define-record-type <inferior-fluid> | |
312 | (inferior-fluid number value) | |
313 | inferior-fluid? | |
314 | (number inferior-fluid-number) | |
315 | (value inferior-fluid-value)) | |
316 | ||
317 | (set-record-type-printer! <inferior-fluid> | |
318 | (lambda (fluid port) | |
319 | (match fluid | |
320 | (($ <inferior-fluid> number) | |
321 | (format port "#<fluid ~a ~x>" | |
322 | number | |
323 | (object-address fluid)))))) | |
324 | ||
325 | ;; Object type to represent complex objects from the inferior process that | |
326 | ;; cannot be really converted to usable Scheme objects in the current | |
327 | ;; process. | |
328 | (define-record-type <inferior-object> | |
329 | (%inferior-object kind sub-kind address) | |
330 | inferior-object? | |
331 | (kind inferior-object-kind) | |
332 | (sub-kind inferior-object-sub-kind) | |
333 | (address inferior-object-address)) | |
334 | ||
335 | (define inferior-object | |
336 | (case-lambda | |
337 | "Return an object representing an inferior object at ADDRESS, of type | |
338 | KIND/SUB-KIND." | |
339 | ((kind address) | |
340 | (%inferior-object kind #f address)) | |
341 | ((kind sub-kind address) | |
342 | (%inferior-object kind sub-kind address)))) | |
343 | ||
344 | (set-record-type-printer! <inferior-object> | |
345 | (lambda (io port) | |
346 | (match io | |
347 | (($ <inferior-object> kind sub-kind address) | |
348 | (format port "#<~a ~:[~*~;~a ~]~x>" | |
349 | kind sub-kind sub-kind | |
350 | address))))) | |
351 | ||
352 | (define (inferior-smob backend type-number address) | |
353 | "Return an object representing the SMOB at ADDRESS whose type is | |
354 | TYPE-NUMBER." | |
355 | (inferior-object 'smob | |
356 | (or (type-number->name backend 'smob type-number) | |
357 | type-number) | |
358 | address)) | |
359 | ||
360 | (define (inferior-port backend type-number address) | |
361 | "Return an object representing the port at ADDRESS whose type is | |
362 | TYPE-NUMBER." | |
363 | (inferior-object 'port | |
364 | (or (type-number->name backend 'port type-number) | |
365 | type-number) | |
366 | address)) | |
367 | ||
368 | (define %visited-cells | |
369 | ;; Vhash of mapping addresses of already visited cells to the | |
370 | ;; corresponding inferior object. This is used to detect and represent | |
371 | ;; cycles. | |
372 | (make-parameter vlist-null)) | |
373 | ||
374 | (define-syntax visited | |
375 | (syntax-rules (->) | |
376 | ((_ (address -> object) body ...) | |
377 | (parameterize ((%visited-cells (vhash-consv address object | |
378 | (%visited-cells)))) | |
379 | body ...)))) | |
380 | ||
381 | (define (address->inferior-struct address vtable-data-address backend) | |
382 | "Read the struct at ADDRESS using BACKEND. Return an 'inferior-struct' | |
383 | object representing it." | |
384 | (define %vtable-layout-index 0) | |
385 | (define %vtable-name-index 5) | |
386 | ||
387 | (let* ((layout-address (+ vtable-data-address | |
388 | (* %vtable-layout-index %word-size))) | |
389 | (layout-bits (dereference-word backend layout-address)) | |
390 | (layout (scm->object layout-bits backend)) | |
391 | (name-address (+ vtable-data-address | |
392 | (* %vtable-name-index %word-size))) | |
393 | (name-bits (dereference-word backend name-address)) | |
394 | (name (scm->object name-bits backend))) | |
395 | (if (symbol? layout) | |
396 | (let* ((layout (symbol->string layout)) | |
397 | (len (/ (string-length layout) 2)) | |
398 | (slots (dereference-word backend (+ address %word-size))) | |
399 | (port (memory-port backend slots (* len %word-size))) | |
400 | (fields (get-bytevector-n port (* len %word-size))) | |
401 | (result (inferior-struct name #f))) | |
402 | ||
403 | ;; Keep track of RESULT so callees can refer to it if we are | |
404 | ;; decoding a circular struct. | |
405 | (visited (address -> result) | |
406 | (let ((values (map (cut scm->object <> backend) | |
407 | (bytevector->uint-list fields | |
408 | (native-endianness) | |
409 | %word-size)))) | |
410 | (set-inferior-struct-fields! result values) | |
411 | result))) | |
412 | (inferior-object 'invalid-struct address)))) | |
413 | ||
414 | (define* (cell->object address #:optional (backend %ffi-memory-backend)) | |
415 | "Return an object representing the object at ADDRESS, reading from memory | |
416 | using BACKEND." | |
417 | (or (and=> (vhash-assv address (%visited-cells)) cdr) ; circular object | |
418 | (let ((port (memory-port backend address))) | |
419 | (match-cell port | |
420 | (((vtable-data-address & 7 = %tc3-struct)) | |
421 | (address->inferior-struct address | |
422 | (- vtable-data-address %tc3-struct) | |
423 | backend)) | |
424 | (((_ & #x7f = %tc7-symbol) buf hash props) | |
425 | (match (cell->object buf backend) | |
426 | (($ <stringbuf> string) | |
427 | (string->symbol string)))) | |
577eab81 AW |
428 | (((_ & #x7f = %tc7-variable) obj) |
429 | (inferior-object 'variable address)) | |
5f4b817d LC |
430 | (((_ & #x7f = %tc7-string) buf start len) |
431 | (match (cell->object buf backend) | |
432 | (($ <stringbuf> string) | |
433 | (substring string start (+ start len))))) | |
434 | (((_ & #x047f = %tc7-stringbuf) len (bytevector buf len)) | |
435 | (stringbuf (bytevector->string buf "ISO-8859-1"))) | |
436 | (((_ & #x047f = (bitwise-ior #x400 %tc7-stringbuf)) | |
437 | len (bytevector buf (* 4 len))) | |
f2de4fac MW |
438 | (stringbuf (bytevector->string buf (match (native-endianness) |
439 | ('little "UTF-32LE") | |
440 | ('big "UTF-32BE"))))) | |
5f4b817d LC |
441 | (((_ & #x7f = %tc7-bytevector) len address) |
442 | (let ((bv-port (memory-port backend address len))) | |
443 | (get-bytevector-all bv-port))) | |
475772ea MW |
444 | ((((len << 8) || %tc7-vector)) |
445 | (let ((words (get-bytevector-n port (* len %word-size))) | |
446 | (vector (make-vector len))) | |
5f4b817d LC |
447 | (visited (address -> vector) |
448 | (fold (lambda (element index) | |
449 | (vector-set! vector index element) | |
450 | (+ 1 index)) | |
451 | 0 | |
452 | (map (cut scm->object <> backend) | |
453 | (bytevector->uint-list words (native-endianness) | |
454 | %word-size))) | |
455 | vector))) | |
e0da53b4 MW |
456 | (((_ & #x7f = %tc7-wvect)) |
457 | (inferior-object 'weak-vector address)) ; TODO: show elements | |
5f4b817d LC |
458 | ((((n << 8) || %tc7-fluid) init-value) |
459 | (inferior-fluid n #f)) ; TODO: show current value | |
460 | (((_ & #x7f = %tc7-dynamic-state)) | |
461 | (inferior-object 'dynamic-state address)) | |
462 | ((((flags+type << 8) || %tc7-port)) | |
463 | (inferior-port backend (logand flags+type #xff) address)) | |
464 | (((_ & #x7f = %tc7-program)) | |
465 | (inferior-object 'program address)) | |
466 | (((_ & #xffff = %tc16-bignum)) | |
467 | (inferior-object 'bignum address)) | |
468 | (((_ & #xffff = %tc16-real) pad) | |
469 | (let* ((address (+ address (* 2 %word-size))) | |
470 | (port (memory-port backend address (sizeof double))) | |
471 | (words (get-bytevector-n port (sizeof double)))) | |
472 | (bytevector-ieee-double-ref words 0 (native-endianness)))) | |
473 | (((_ & #x7f = %tc7-number) mpi) | |
474 | (inferior-object 'number address)) | |
475 | (((_ & #x7f = %tc7-hashtable) buckets meta-data unused) | |
476 | (inferior-object 'hash-table address)) | |
477 | (((_ & #x7f = %tc7-pointer) address) | |
478 | (make-pointer address)) | |
e2fafeb9 AW |
479 | (((_ & #x7f = %tc7-keyword) symbol) |
480 | (symbol->keyword (cell->object symbol backend))) | |
5f4b817d LC |
481 | (((_ & #x7f = %tc7-vm-continuation)) |
482 | (inferior-object 'vm-continuation address)) | |
475772ea MW |
483 | (((_ & #x7f = %tc7-weak-set)) |
484 | (inferior-object 'weak-set address)) | |
485 | (((_ & #x7f = %tc7-weak-table)) | |
486 | (inferior-object 'weak-table address)) | |
e0da53b4 MW |
487 | (((_ & #x7f = %tc7-array)) |
488 | (inferior-object 'array address)) | |
489 | (((_ & #x7f = %tc7-bitvector)) | |
490 | (inferior-object 'bitvector address)) | |
5f4b817d LC |
491 | ((((smob-type << 8) || %tc7-smob) word1) |
492 | (inferior-smob backend smob-type address)))))) | |
493 | ||
494 | ||
495 | (define* (scm->object bits #:optional (backend %ffi-memory-backend)) | |
496 | "Return the Scheme object corresponding to BITS, the bits of an 'SCM' | |
497 | object." | |
498 | (match-scm bits | |
499 | (((integer << 2) || %tc2-int) | |
500 | integer) | |
501 | ((address & 6 = %tc3-cons) | |
502 | (let* ((type (dereference-word backend address)) | |
503 | (pair? (not (bit-set? 0 type)))) | |
504 | (if pair? | |
505 | (or (and=> (vhash-assv address (%visited-cells)) cdr) | |
506 | (let ((car type) | |
507 | (cdrloc (+ address %word-size)) | |
508 | (pair (cons *unspecified* *unspecified*))) | |
509 | (visited (address -> pair) | |
510 | (set-car! pair (scm->object car backend)) | |
511 | (set-cdr! pair | |
512 | (scm->object (dereference-word backend cdrloc) | |
513 | backend)) | |
514 | pair))) | |
515 | (cell->object address backend)))) | |
516 | (((char << 8) || %tc8-char) | |
517 | (integer->char char)) | |
518 | (((flag << 8) || %tc8-flag) | |
519 | (case flag | |
520 | ((0) #f) | |
521 | ((1) #nil) | |
522 | ((3) '()) | |
523 | ((4) #t) | |
524 | ((8) (if #f #f)) | |
525 | ((9) (inferior-object 'undefined bits)) | |
526 | ((10) (eof-object)) | |
527 | ((11) (inferior-object 'unbound bits)))))) | |
528 | ||
529 | ;;; Local Variables: | |
530 | ;;; eval: (put 'match-scm 'scheme-indent-function 1) | |
531 | ;;; eval: (put 'match-cell 'scheme-indent-function 1) | |
532 | ;;; eval: (put 'visited 'scheme-indent-function 1) | |
533 | ;;; End: | |
534 | ||
535 | ;;; types.scm ends here |