Commit | Line | Data |
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6f03035f | 1 | /* Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2007, 2008 Free Software Foundation, Inc. |
0f2d19dd | 2 | * |
73be1d9e MV |
3 | * This library is free software; you can redistribute it and/or |
4 | * modify it under the terms of the GNU Lesser General Public | |
5 | * License as published by the Free Software Foundation; either | |
6 | * version 2.1 of the License, or (at your option) any later version. | |
0f2d19dd | 7 | * |
73be1d9e MV |
8 | * This library is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * Lesser General Public License for more details. | |
0f2d19dd | 12 | * |
73be1d9e MV |
13 | * You should have received a copy of the GNU Lesser General Public |
14 | * License along with this library; if not, write to the Free Software | |
92205699 | 15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
73be1d9e | 16 | */ |
1bbd0b84 | 17 | |
0f2d19dd | 18 | \f |
dbb605f5 | 19 | #ifdef HAVE_CONFIG_H |
a6f7f57d RB |
20 | # include <config.h> |
21 | #endif | |
0f2d19dd | 22 | |
a0599745 | 23 | #include "libguile/_scm.h" |
4e047c3e | 24 | #include "libguile/async.h" |
a0599745 MD |
25 | #include "libguile/chars.h" |
26 | #include "libguile/eval.h" | |
27 | #include "libguile/alist.h" | |
28 | #include "libguile/weaks.h" | |
29 | #include "libguile/hashtab.h" | |
30 | #include "libguile/ports.h" | |
31 | #include "libguile/strings.h" | |
32 | ||
33 | #include "libguile/validate.h" | |
34 | #include "libguile/struct.h" | |
0f2d19dd | 35 | |
d15ad007 LC |
36 | #include "libguile/eq.h" |
37 | ||
95b88819 GH |
38 | #ifdef HAVE_STRING_H |
39 | #include <string.h> | |
40 | #endif | |
41 | ||
e7bca227 | 42 | #include "libguile/boehm-gc.h" |
5e67dc27 | 43 | |
0f2d19dd JB |
44 | \f |
45 | ||
46 | static SCM required_vtable_fields = SCM_BOOL_F; | |
98d5f601 | 47 | SCM scm_struct_table; |
0f2d19dd JB |
48 | |
49 | \f | |
a1ec6916 | 50 | SCM_DEFINE (scm_make_struct_layout, "make-struct-layout", 1, 0, 0, |
1bbd0b84 | 51 | (SCM fields), |
b380b885 | 52 | "Return a new structure layout object.\n\n" |
7c31152f | 53 | "@var{fields} must be a string made up of pairs of characters\n" |
b380b885 MD |
54 | "strung together. The first character of each pair describes a field\n" |
55 | "type, the second a field protection. Allowed types are 'p' for\n" | |
56 | "GC-protected Scheme data, 'u' for unprotected binary data, and 's' for\n" | |
04323af4 | 57 | "a field that points to the structure itself. Allowed protections\n" |
9401323e | 58 | "are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque\n" |
b380b885 MD |
59 | "fields. The last field protection specification may be capitalized to\n" |
60 | "indicate that the field is a tail-array.") | |
1bbd0b84 | 61 | #define FUNC_NAME s_scm_make_struct_layout |
0f2d19dd JB |
62 | { |
63 | SCM new_sym; | |
d1ca2c64 | 64 | SCM_VALIDATE_STRING (1, fields); |
2ade72d7 | 65 | |
1bbd0b84 | 66 | { /* scope */ |
cc95e00a | 67 | const char * field_desc; |
1be6b49c | 68 | size_t len; |
0f2d19dd JB |
69 | int x; |
70 | ||
cc95e00a | 71 | len = scm_i_string_length (fields); |
2ade72d7 DH |
72 | if (len % 2 == 1) |
73 | SCM_MISC_ERROR ("odd length field specification: ~S", | |
1afff620 | 74 | scm_list_1 (fields)); |
2ade72d7 | 75 | |
cc95e00a | 76 | field_desc = scm_i_string_chars (fields); |
0f2d19dd JB |
77 | |
78 | for (x = 0; x < len; x += 2) | |
79 | { | |
80 | switch (field_desc[x]) | |
81 | { | |
82 | case 'u': | |
83 | case 'p': | |
84 | #if 0 | |
85 | case 'i': | |
86 | case 'd': | |
87 | #endif | |
88 | case 's': | |
89 | break; | |
90 | default: | |
2ade72d7 | 91 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 92 | scm_list_1 (SCM_MAKE_CHAR (field_desc[x]))); |
0f2d19dd JB |
93 | } |
94 | ||
95 | switch (field_desc[x + 1]) | |
96 | { | |
97 | case 'w': | |
2ade72d7 DH |
98 | if (field_desc[x] == 's') |
99 | SCM_MISC_ERROR ("self fields not writable", SCM_EOL); | |
0f2d19dd JB |
100 | case 'r': |
101 | case 'o': | |
102 | break; | |
2c36c351 MD |
103 | case 'R': |
104 | case 'W': | |
105 | case 'O': | |
2ade72d7 DH |
106 | if (field_desc[x] == 's') |
107 | SCM_MISC_ERROR ("self fields not allowed in tail array", | |
108 | SCM_EOL); | |
109 | if (x != len - 2) | |
110 | SCM_MISC_ERROR ("tail array field must be last field in layout", | |
111 | SCM_EOL); | |
2c36c351 | 112 | break; |
0f2d19dd | 113 | default: |
2ade72d7 | 114 | SCM_MISC_ERROR ("unrecognized ref specification: ~S", |
1afff620 | 115 | scm_list_1 (SCM_MAKE_CHAR (field_desc[x + 1]))); |
0f2d19dd JB |
116 | } |
117 | #if 0 | |
118 | if (field_desc[x] == 'd') | |
119 | { | |
2ade72d7 DH |
120 | if (field_desc[x + 2] != '-') |
121 | SCM_MISC_ERROR ("missing dash field at position ~A", | |
e11e83f3 | 122 | scm_list_1 (scm_from_int (x / 2))); |
0f2d19dd JB |
123 | x += 2; |
124 | goto recheck_ref; | |
125 | } | |
126 | #endif | |
127 | } | |
cc95e00a | 128 | new_sym = scm_string_to_symbol (fields); |
0f2d19dd | 129 | } |
8824ac88 MV |
130 | scm_remember_upto_here_1 (fields); |
131 | return new_sym; | |
0f2d19dd | 132 | } |
1bbd0b84 | 133 | #undef FUNC_NAME |
0f2d19dd JB |
134 | |
135 | \f | |
136 | ||
137 | ||
1cc91f1b | 138 | |
f7620510 | 139 | static void |
92c2555f | 140 | scm_struct_init (SCM handle, SCM layout, scm_t_bits * mem, int tail_elts, SCM inits) |
0f2d19dd | 141 | { |
cc95e00a MV |
142 | unsigned const char *fields_desc = |
143 | (unsigned const char *) scm_i_symbol_chars (layout) - 2; | |
35de7ebe | 144 | unsigned char prot = 0; |
cc95e00a | 145 | int n_fields = scm_i_symbol_length (layout) / 2; |
2c36c351 | 146 | int tailp = 0; |
d8c40b9f | 147 | |
0f2d19dd JB |
148 | while (n_fields) |
149 | { | |
2c36c351 MD |
150 | if (!tailp) |
151 | { | |
152 | fields_desc += 2; | |
153 | prot = fields_desc[1]; | |
154 | if (SCM_LAYOUT_TAILP (prot)) | |
155 | { | |
156 | tailp = 1; | |
157 | prot = prot == 'R' ? 'r' : prot == 'W' ? 'w' : 'o'; | |
d8c40b9f | 158 | *mem++ = tail_elts; |
2c36c351 MD |
159 | n_fields += tail_elts - 1; |
160 | if (n_fields == 0) | |
161 | break; | |
162 | } | |
163 | } | |
164 | ||
0f2d19dd JB |
165 | switch (*fields_desc) |
166 | { | |
167 | #if 0 | |
168 | case 'i': | |
2c36c351 | 169 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
170 | *mem = 0; |
171 | else | |
172 | { | |
b9bd8526 | 173 | *mem = scm_to_long (SCM_CAR (inits)); |
0f2d19dd JB |
174 | inits = SCM_CDR (inits); |
175 | } | |
176 | break; | |
177 | #endif | |
178 | ||
179 | case 'u': | |
d2e53ed6 | 180 | if ((prot != 'r' && prot != 'w') || scm_is_null (inits)) |
0f2d19dd JB |
181 | *mem = 0; |
182 | else | |
183 | { | |
b9bd8526 | 184 | *mem = scm_to_ulong (SCM_CAR (inits)); |
0f2d19dd JB |
185 | inits = SCM_CDR (inits); |
186 | } | |
187 | break; | |
188 | ||
189 | case 'p': | |
d2e53ed6 | 190 | if ((prot != 'r' && prot != 'w') || scm_is_null (inits)) |
d8c40b9f | 191 | *mem = SCM_UNPACK (SCM_BOOL_F); |
0f2d19dd JB |
192 | else |
193 | { | |
d8c40b9f | 194 | *mem = SCM_UNPACK (SCM_CAR (inits)); |
0f2d19dd JB |
195 | inits = SCM_CDR (inits); |
196 | } | |
197 | ||
198 | break; | |
199 | ||
200 | #if 0 | |
201 | case 'd': | |
2c36c351 | 202 | if ((prot != 'r' && prot != 'w') || inits == SCM_EOL) |
0f2d19dd JB |
203 | *((double *)mem) = 0.0; |
204 | else | |
205 | { | |
a5bfe84d | 206 | *mem = scm_num2dbl (SCM_CAR (inits), "scm_struct_init"); |
0f2d19dd JB |
207 | inits = SCM_CDR (inits); |
208 | } | |
209 | fields_desc += 2; | |
210 | break; | |
211 | #endif | |
212 | ||
213 | case 's': | |
d8c40b9f | 214 | *mem = SCM_UNPACK (handle); |
0f2d19dd JB |
215 | break; |
216 | } | |
217 | ||
0f2d19dd JB |
218 | n_fields--; |
219 | mem++; | |
220 | } | |
221 | } | |
222 | ||
223 | ||
a1ec6916 | 224 | SCM_DEFINE (scm_struct_p, "struct?", 1, 0, 0, |
1bbd0b84 | 225 | (SCM x), |
0233bfc1 | 226 | "Return @code{#t} iff @var{x} is a structure object, else\n" |
942e5b91 | 227 | "@code{#f}.") |
1bbd0b84 | 228 | #define FUNC_NAME s_scm_struct_p |
0f2d19dd | 229 | { |
7888309b | 230 | return scm_from_bool(SCM_STRUCTP (x)); |
0f2d19dd | 231 | } |
1bbd0b84 | 232 | #undef FUNC_NAME |
0f2d19dd | 233 | |
a1ec6916 | 234 | SCM_DEFINE (scm_struct_vtable_p, "struct-vtable?", 1, 0, 0, |
1bbd0b84 | 235 | (SCM x), |
0233bfc1 | 236 | "Return @code{#t} iff @var{x} is a vtable structure.") |
1bbd0b84 | 237 | #define FUNC_NAME s_scm_struct_vtable_p |
0f2d19dd JB |
238 | { |
239 | SCM layout; | |
92c2555f | 240 | scm_t_bits * mem; |
8824ac88 | 241 | int tmp; |
0f2d19dd JB |
242 | |
243 | if (!SCM_STRUCTP (x)) | |
244 | return SCM_BOOL_F; | |
245 | ||
246 | layout = SCM_STRUCT_LAYOUT (x); | |
247 | ||
cc95e00a MV |
248 | if (scm_i_symbol_length (layout) |
249 | < scm_i_string_length (required_vtable_fields)) | |
0f2d19dd JB |
250 | return SCM_BOOL_F; |
251 | ||
cc95e00a MV |
252 | tmp = strncmp (scm_i_symbol_chars (layout), |
253 | scm_i_string_chars (required_vtable_fields), | |
254 | scm_i_string_length (required_vtable_fields)); | |
8824ac88 MV |
255 | scm_remember_upto_here_1 (required_vtable_fields); |
256 | if (tmp) | |
0f2d19dd JB |
257 | return SCM_BOOL_F; |
258 | ||
259 | mem = SCM_STRUCT_DATA (x); | |
260 | ||
cc95e00a | 261 | return scm_from_bool (scm_is_symbol (SCM_PACK (mem[scm_vtable_index_layout]))); |
0f2d19dd | 262 | } |
1bbd0b84 | 263 | #undef FUNC_NAME |
0f2d19dd | 264 | |
14d1400f JB |
265 | |
266 | /* All struct data must be allocated at an address whose bottom three | |
267 | bits are zero. This is because the tag for a struct lives in the | |
268 | bottom three bits of the struct's car, and the upper bits point to | |
269 | the data of its vtable, which is a struct itself. Thus, if the | |
270 | address of that data doesn't end in three zeros, tagging it will | |
271 | destroy the pointer. | |
272 | ||
273 | This function allocates a block of memory, and returns a pointer at | |
274 | least scm_struct_n_extra_words words into the block. Furthermore, | |
275 | it guarantees that that pointer's least three significant bits are | |
276 | all zero. | |
277 | ||
278 | The argument n_words should be the number of words that should | |
279 | appear after the returned address. (That is, it shouldn't include | |
280 | scm_struct_n_extra_words.) | |
281 | ||
282 | This function initializes the following fields of the struct: | |
283 | ||
ad196599 | 284 | scm_struct_i_ptr --- the actual start of the block of memory; the |
14d1400f JB |
285 | address you should pass to 'free' to dispose of the block. |
286 | This field allows us to both guarantee that the returned | |
287 | address is divisible by eight, and allow the GC to free the | |
288 | block. | |
289 | ||
290 | scm_struct_i_n_words --- the number of words allocated to the | |
291 | block, including the extra fields. This is used by the GC. | |
292 | ||
14d1400f JB |
293 | Ugh. */ |
294 | ||
295 | ||
92c2555f | 296 | scm_t_bits * |
4c9419ac | 297 | scm_alloc_struct (int n_words, int n_extra, const char *what) |
14d1400f | 298 | { |
92c2555f | 299 | int size = sizeof (scm_t_bits) * (n_words + n_extra) + 7; |
4c9419ac | 300 | void * block = scm_gc_malloc (size, what); |
14d1400f JB |
301 | |
302 | /* Adjust the pointer to hide the extra words. */ | |
92c2555f | 303 | scm_t_bits * p = (scm_t_bits *) block + n_extra; |
14d1400f JB |
304 | |
305 | /* Adjust it even further so it's aligned on an eight-byte boundary. */ | |
92c2555f | 306 | p = (scm_t_bits *) (((scm_t_bits) p + 7) & ~7); |
14d1400f | 307 | |
ad196599 | 308 | /* Initialize a few fields as described above. */ |
6cc80cb6 | 309 | p[scm_struct_i_free] = (scm_t_bits) 0; |
92c2555f | 310 | p[scm_struct_i_ptr] = (scm_t_bits) block; |
c8045e8d | 311 | p[scm_struct_i_n_words] = n_words; |
ad196599 | 312 | p[scm_struct_i_flags] = 0; |
14d1400f | 313 | |
184327a6 LC |
314 | /* Since `SCM' objects will record either P or P + SCM_TC3_STRUCT, we need |
315 | to register them as valid displacements. Fortunately, only a handful of | |
316 | N_EXTRA values are used in core Guile. */ | |
317 | GC_REGISTER_DISPLACEMENT ((char *)p - (char *)block); | |
318 | GC_REGISTER_DISPLACEMENT ((char *)p - (char *)block + scm_tc3_struct); | |
319 | ||
14d1400f JB |
320 | return p; |
321 | } | |
322 | ||
5e67dc27 LC |
323 | \f |
324 | /* Finalization. */ | |
325 | ||
326 | ||
327 | /* Invoke the finalizer of the struct pointed to by PTR. */ | |
328 | static void | |
329 | struct_finalizer_trampoline (GC_PTR ptr, GC_PTR unused_data) | |
330 | { | |
331 | SCM obj = PTR2SCM (ptr); | |
332 | ||
333 | /* XXX - use less explicit code. */ | |
334 | scm_t_bits word0 = SCM_CELL_WORD_0 (obj) - scm_tc3_struct; | |
335 | scm_t_bits *vtable_data = (scm_t_bits *) word0; | |
336 | scm_t_bits *data = SCM_STRUCT_DATA (obj); | |
337 | scm_t_struct_free free_struct_data | |
338 | = ((scm_t_struct_free) vtable_data[scm_struct_i_free]); | |
339 | ||
340 | SCM_SET_CELL_TYPE (obj, scm_tc_free_cell); | |
341 | ||
342 | #if 0 | |
343 | /* A sanity check. However, this check can fail if the free function | |
344 | changed between the `make-struct' time and now. */ | |
345 | if (free_struct_data != (scm_t_struct_free)unused_data) | |
346 | abort (); | |
347 | #endif | |
348 | ||
349 | if (free_struct_data) | |
350 | free_struct_data (vtable_data, data); | |
351 | } | |
352 | ||
353 | ||
354 | ||
5e67dc27 | 355 | \f |
a1ec6916 | 356 | SCM_DEFINE (scm_make_struct, "make-struct", 2, 0, 1, |
1bbd0b84 | 357 | (SCM vtable, SCM tail_array_size, SCM init), |
b380b885 | 358 | "Create a new structure.\n\n" |
1bee0e70 | 359 | "@var{type} must be a vtable structure (@pxref{Vtables}).\n\n" |
b380b885 MD |
360 | "@var{tail-elts} must be a non-negative integer. If the layout\n" |
361 | "specification indicated by @var{type} includes a tail-array,\n" | |
362 | "this is the number of elements allocated to that array.\n\n" | |
6386e25c | 363 | "The @var{init1}, @dots{} are optional arguments describing how\n" |
04323af4 MD |
364 | "successive fields of the structure should be initialized. Only fields\n" |
365 | "with protection 'r' or 'w' can be initialized, except for fields of\n" | |
366 | "type 's', which are automatically initialized to point to the new\n" | |
367 | "structure itself; fields with protection 'o' can not be initialized by\n" | |
368 | "Scheme programs.\n\n" | |
369 | "If fewer optional arguments than initializable fields are supplied,\n" | |
370 | "fields of type 'p' get default value #f while fields of type 'u' are\n" | |
371 | "initialized to 0.\n\n" | |
372 | "Structs are currently the basic representation for record-like data\n" | |
373 | "structures in Guile. The plan is to eventually replace them with a\n" | |
374 | "new representation which will at the same time be easier to use and\n" | |
375 | "more powerful.\n\n" | |
6386e25c | 376 | "For more information, see the documentation for @code{make-vtable-vtable}.") |
1bbd0b84 | 377 | #define FUNC_NAME s_scm_make_struct |
0f2d19dd JB |
378 | { |
379 | SCM layout; | |
a55c2b68 MV |
380 | size_t basic_size; |
381 | size_t tail_elts; | |
5e67dc27 | 382 | scm_t_bits *data, *c_vtable; |
0f2d19dd JB |
383 | SCM handle; |
384 | ||
34d19ef6 | 385 | SCM_VALIDATE_VTABLE (1, vtable); |
af45e3b0 | 386 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 387 | |
5e67dc27 LC |
388 | c_vtable = SCM_STRUCT_DATA (vtable); |
389 | ||
390 | layout = SCM_PACK (c_vtable [scm_vtable_index_layout]); | |
cc95e00a | 391 | basic_size = scm_i_symbol_length (layout) / 2; |
a55c2b68 | 392 | tail_elts = scm_to_size_t (tail_array_size); |
651f2cd2 KR |
393 | |
394 | /* A tail array is only allowed if the layout fields string ends in "R", | |
395 | "W" or "O". */ | |
396 | if (tail_elts != 0) | |
397 | { | |
398 | SCM layout_str, last_char; | |
399 | ||
400 | if (basic_size == 0) | |
401 | { | |
402 | bad_tail: | |
403 | SCM_MISC_ERROR ("tail array not allowed unless layout ends R, W, or O", SCM_EOL); | |
404 | } | |
405 | ||
406 | layout_str = scm_symbol_to_string (layout); | |
407 | last_char = scm_string_ref (layout_str, | |
408 | scm_from_size_t (2 * basic_size - 1)); | |
409 | if (! SCM_LAYOUT_TAILP (SCM_CHAR (last_char))) | |
410 | goto bad_tail; | |
411 | } | |
cb823e63 LC |
412 | |
413 | /* In guile 1.8.5 and earlier, everything below was covered by a | |
414 | CRITICAL_SECTION lock. This can lead to deadlocks in garbage | |
415 | collection, since other threads might be holding the heap_mutex, while | |
416 | sleeping on the CRITICAL_SECTION lock. There does not seem to be any | |
417 | need for a lock on the section below, as it does not access or update | |
418 | any globals, so the critical section has been removed. */ | |
419 | ||
5e67dc27 | 420 | if (c_vtable[scm_struct_i_flags] & SCM_STRUCTF_ENTITY) |
a5bfe84d MD |
421 | { |
422 | data = scm_alloc_struct (basic_size + tail_elts, | |
98d5f601 | 423 | scm_struct_entity_n_extra_words, |
4c9419ac | 424 | "entity struct"); |
c8045e8d DH |
425 | data[scm_struct_i_procedure] = SCM_UNPACK (SCM_BOOL_F); |
426 | data[scm_struct_i_setter] = SCM_UNPACK (SCM_BOOL_F); | |
a5bfe84d MD |
427 | } |
428 | else | |
429 | data = scm_alloc_struct (basic_size + tail_elts, | |
430 | scm_struct_n_extra_words, | |
4c9419ac | 431 | "struct"); |
5e67dc27 | 432 | handle = scm_double_cell ((((scm_t_bits) c_vtable) |
228a24ef DH |
433 | + scm_tc3_struct), |
434 | (scm_t_bits) data, 0, 0); | |
5e67dc27 LC |
435 | |
436 | if (c_vtable[scm_struct_i_free]) | |
437 | { | |
438 | /* Register a finalizer for the newly created instance. */ | |
439 | GC_finalization_proc prev_finalizer; | |
440 | GC_PTR prev_finalizer_data; | |
441 | scm_t_struct_free free_struct = | |
442 | (scm_t_struct_free)c_vtable[scm_struct_i_free]; | |
443 | ||
444 | GC_REGISTER_FINALIZER_NO_ORDER (SCM2PTR (handle), | |
445 | struct_finalizer_trampoline, | |
446 | free_struct, | |
447 | &prev_finalizer, | |
448 | &prev_finalizer_data); | |
449 | } | |
450 | ||
651f2cd2 KR |
451 | scm_struct_init (handle, layout, data, tail_elts, init); |
452 | ||
0f2d19dd JB |
453 | return handle; |
454 | } | |
1bbd0b84 | 455 | #undef FUNC_NAME |
0f2d19dd JB |
456 | |
457 | ||
458 | ||
a1ec6916 | 459 | SCM_DEFINE (scm_make_vtable_vtable, "make-vtable-vtable", 2, 0, 1, |
04323af4 | 460 | (SCM user_fields, SCM tail_array_size, SCM init), |
b380b885 | 461 | "Return a new, self-describing vtable structure.\n\n" |
04323af4 MD |
462 | "@var{user-fields} is a string describing user defined fields of the\n" |
463 | "vtable beginning at index @code{vtable-offset-user}\n" | |
464 | "(see @code{make-struct-layout}).\n\n" | |
b380b885 MD |
465 | "@var{tail-size} specifies the size of the tail-array (if any) of\n" |
466 | "this vtable.\n\n" | |
6386e25c | 467 | "@var{init1}, @dots{} are the optional initializers for the fields of\n" |
04323af4 MD |
468 | "the vtable.\n\n" |
469 | "Vtables have one initializable system field---the struct printer.\n" | |
470 | "This field comes before the user fields in the initializers passed\n" | |
471 | "to @code{make-vtable-vtable} and @code{make-struct}, and thus works as\n" | |
472 | "a third optional argument to @code{make-vtable-vtable} and a fourth to\n" | |
473 | "@code{make-struct} when creating vtables:\n\n" | |
474 | "If the value is a procedure, it will be called instead of the standard\n" | |
475 | "printer whenever a struct described by this vtable is printed.\n" | |
476 | "The procedure will be called with arguments STRUCT and PORT.\n\n" | |
477 | "The structure of a struct is described by a vtable, so the vtable is\n" | |
478 | "in essence the type of the struct. The vtable is itself a struct with\n" | |
479 | "a vtable. This could go on forever if it weren't for the\n" | |
29b4f9fb | 480 | "vtable-vtables which are self-describing vtables, and thus terminate\n" |
04323af4 MD |
481 | "the chain.\n\n" |
482 | "There are several potential ways of using structs, but the standard\n" | |
483 | "one is to use three kinds of structs, together building up a type\n" | |
484 | "sub-system: one vtable-vtable working as the root and one or several\n" | |
485 | "\"types\", each with a set of \"instances\". (The vtable-vtable should be\n" | |
29b4f9fb | 486 | "compared to the class <class> which is the class of itself.)\n\n" |
1e6808ea | 487 | "@lisp\n" |
04323af4 MD |
488 | "(define ball-root (make-vtable-vtable \"pr\" 0))\n\n" |
489 | "(define (make-ball-type ball-color)\n" | |
490 | " (make-struct ball-root 0\n" | |
491 | " (make-struct-layout \"pw\")\n" | |
492 | " (lambda (ball port)\n" | |
493 | " (format port \"#<a ~A ball owned by ~A>\"\n" | |
494 | " (color ball)\n" | |
495 | " (owner ball)))\n" | |
496 | " ball-color))\n" | |
497 | "(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))\n" | |
498 | "(define (owner ball) (struct-ref ball 0))\n\n" | |
499 | "(define red (make-ball-type 'red))\n" | |
500 | "(define green (make-ball-type 'green))\n\n" | |
501 | "(define (make-ball type owner) (make-struct type 0 owner))\n\n" | |
502 | "(define ball (make-ball green 'Nisse))\n" | |
503 | "ball @result{} #<a green ball owned by Nisse>\n" | |
9401323e | 504 | "@end lisp") |
1bbd0b84 | 505 | #define FUNC_NAME s_scm_make_vtable_vtable |
0f2d19dd JB |
506 | { |
507 | SCM fields; | |
508 | SCM layout; | |
a55c2b68 MV |
509 | size_t basic_size; |
510 | size_t tail_elts; | |
511 | scm_t_bits *data; | |
0f2d19dd JB |
512 | SCM handle; |
513 | ||
d1ca2c64 | 514 | SCM_VALIDATE_STRING (1, user_fields); |
af45e3b0 | 515 | SCM_VALIDATE_REST_ARGUMENT (init); |
0f2d19dd | 516 | |
1afff620 KN |
517 | fields = scm_string_append (scm_list_2 (required_vtable_fields, |
518 | user_fields)); | |
0f2d19dd | 519 | layout = scm_make_struct_layout (fields); |
cc95e00a | 520 | basic_size = scm_i_symbol_length (layout) / 2; |
a55c2b68 | 521 | tail_elts = scm_to_size_t (tail_array_size); |
9de87eea | 522 | SCM_CRITICAL_SECTION_START; |
a5bfe84d MD |
523 | data = scm_alloc_struct (basic_size + tail_elts, |
524 | scm_struct_n_extra_words, | |
4c9419ac | 525 | "struct"); |
228a24ef DH |
526 | handle = scm_double_cell ((scm_t_bits) data + scm_tc3_struct, |
527 | (scm_t_bits) data, 0, 0); | |
f7620510 DH |
528 | data [scm_vtable_index_layout] = SCM_UNPACK (layout); |
529 | scm_struct_init (handle, layout, data, tail_elts, scm_cons (layout, init)); | |
9de87eea | 530 | SCM_CRITICAL_SECTION_END; |
0f2d19dd JB |
531 | return handle; |
532 | } | |
1bbd0b84 | 533 | #undef FUNC_NAME |
0f2d19dd | 534 | |
d15ad007 | 535 | |
651f2cd2 KR |
536 | static SCM scm_i_vtable_vtable_no_extra_fields; |
537 | ||
538 | SCM_DEFINE (scm_make_vtable, "make-vtable", 1, 1, 0, | |
539 | (SCM fields, SCM printer), | |
540 | "Create a vtable, for creating structures with the given\n" | |
541 | "@var{fields}.\n" | |
542 | "\n" | |
543 | "The optional @var{printer} argument is a function to be called\n" | |
544 | "@code{(@var{printer} struct port)} on the structures created.\n" | |
545 | "It should look at @var{struct} and write to @var{port}.") | |
546 | #define FUNC_NAME s_scm_make_vtable | |
547 | { | |
548 | if (SCM_UNBNDP (printer)) | |
549 | printer = SCM_BOOL_F; | |
550 | ||
551 | return scm_make_struct (scm_i_vtable_vtable_no_extra_fields, SCM_INUM0, | |
552 | scm_list_2 (scm_make_struct_layout (fields), | |
553 | printer)); | |
554 | } | |
555 | #undef FUNC_NAME | |
556 | ||
557 | ||
d15ad007 LC |
558 | /* Return true if S1 and S2 are equal structures, i.e., if their vtable and |
559 | contents are the same. Field protections are honored. Thus, it is an | |
560 | error to test the equality of structures that contain opaque fields. */ | |
561 | SCM | |
562 | scm_i_struct_equalp (SCM s1, SCM s2) | |
563 | #define FUNC_NAME "scm_i_struct_equalp" | |
564 | { | |
565 | SCM vtable1, vtable2, layout; | |
566 | size_t struct_size, field_num; | |
567 | ||
568 | SCM_VALIDATE_STRUCT (1, s1); | |
569 | SCM_VALIDATE_STRUCT (2, s2); | |
570 | ||
571 | vtable1 = SCM_STRUCT_VTABLE (s1); | |
572 | vtable2 = SCM_STRUCT_VTABLE (s2); | |
573 | ||
574 | if (!scm_is_eq (vtable1, vtable2)) | |
575 | return SCM_BOOL_F; | |
576 | ||
577 | layout = SCM_STRUCT_LAYOUT (s1); | |
578 | struct_size = scm_i_symbol_length (layout) / 2; | |
579 | ||
580 | for (field_num = 0; field_num < struct_size; field_num++) | |
581 | { | |
582 | SCM s_field_num; | |
583 | SCM field1, field2; | |
584 | ||
585 | /* We have to use `scm_struct_ref ()' here so that fields are accessed | |
586 | consistently, notably wrt. field types and access rights. */ | |
587 | s_field_num = scm_from_size_t (field_num); | |
588 | field1 = scm_struct_ref (s1, s_field_num); | |
589 | field2 = scm_struct_ref (s2, s_field_num); | |
590 | ||
42ddb3cb LC |
591 | /* Self-referencing fields (type `s') must be skipped to avoid infinite |
592 | recursion. */ | |
593 | if (!(scm_is_eq (field1, s1) && (scm_is_eq (field2, s2)))) | |
594 | if (scm_is_false (scm_equal_p (field1, field2))) | |
595 | return SCM_BOOL_F; | |
d15ad007 LC |
596 | } |
597 | ||
42ddb3cb LC |
598 | /* FIXME: Tail elements should be tested for equality. */ |
599 | ||
d15ad007 LC |
600 | return SCM_BOOL_T; |
601 | } | |
602 | #undef FUNC_NAME | |
603 | ||
604 | ||
0f2d19dd JB |
605 | \f |
606 | ||
607 | ||
a1ec6916 | 608 | SCM_DEFINE (scm_struct_ref, "struct-ref", 2, 0, 0, |
1bbd0b84 | 609 | (SCM handle, SCM pos), |
8f85c0c6 | 610 | "@deffnx {Scheme Procedure} struct-set! struct n value\n" |
b380b885 MD |
611 | "Access (or modify) the @var{n}th field of @var{struct}.\n\n" |
612 | "If the field is of type 'p', then it can be set to an arbitrary value.\n\n" | |
613 | "If the field is of type 'u', then it can only be set to a non-negative\n" | |
614 | "integer value small enough to fit in one machine word.") | |
1bbd0b84 | 615 | #define FUNC_NAME s_scm_struct_ref |
0f2d19dd | 616 | { |
5e840c2e | 617 | SCM answer = SCM_UNDEFINED; |
92c2555f | 618 | scm_t_bits * data; |
0f2d19dd | 619 | SCM layout; |
cc95e00a | 620 | size_t layout_len; |
a55c2b68 | 621 | size_t p; |
92c2555f | 622 | scm_t_bits n_fields; |
cc95e00a | 623 | const char *fields_desc; |
e51fe79c | 624 | char field_type = 0; |
0f2d19dd JB |
625 | |
626 | ||
34d19ef6 | 627 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
628 | |
629 | layout = SCM_STRUCT_LAYOUT (handle); | |
630 | data = SCM_STRUCT_DATA (handle); | |
a55c2b68 | 631 | p = scm_to_size_t (pos); |
0f2d19dd | 632 | |
cc95e00a MV |
633 | fields_desc = scm_i_symbol_chars (layout); |
634 | layout_len = scm_i_symbol_length (layout); | |
4650d115 AW |
635 | if (SCM_STRUCT_VTABLE_FLAGS (handle) & SCM_STRUCTF_LIGHT) |
636 | /* no extra words */ | |
637 | n_fields = layout_len / 2; | |
638 | else | |
639 | n_fields = data[scm_struct_i_n_words]; | |
2c36c351 | 640 | |
34d19ef6 | 641 | SCM_ASSERT_RANGE(1, pos, p < n_fields); |
0f2d19dd | 642 | |
cc95e00a | 643 | if (p * 2 < layout_len) |
2c36c351 | 644 | { |
e51fe79c | 645 | char ref; |
2c36c351 MD |
646 | field_type = fields_desc[p * 2]; |
647 | ref = fields_desc[p * 2 + 1]; | |
648 | if ((ref != 'r') && (ref != 'w')) | |
649 | { | |
650 | if ((ref == 'R') || (ref == 'W')) | |
651 | field_type = 'u'; | |
652 | else | |
1afff620 | 653 | SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos)); |
2c36c351 MD |
654 | } |
655 | } | |
cc95e00a MV |
656 | else if (fields_desc[layout_len - 1] != 'O') |
657 | field_type = fields_desc[layout_len - 2]; | |
2c36c351 | 658 | else |
1afff620 | 659 | SCM_MISC_ERROR ("ref denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 660 | |
0f2d19dd JB |
661 | switch (field_type) |
662 | { | |
663 | case 'u': | |
b9bd8526 | 664 | answer = scm_from_ulong (data[p]); |
0f2d19dd JB |
665 | break; |
666 | ||
667 | #if 0 | |
668 | case 'i': | |
b9bd8526 | 669 | answer = scm_from_long (data[p]); |
0f2d19dd JB |
670 | break; |
671 | ||
672 | case 'd': | |
f8de44c1 | 673 | answer = scm_make_real (*((double *)&(data[p]))); |
0f2d19dd JB |
674 | break; |
675 | #endif | |
676 | ||
677 | case 's': | |
678 | case 'p': | |
d8c40b9f | 679 | answer = SCM_PACK (data[p]); |
0f2d19dd JB |
680 | break; |
681 | ||
682 | ||
683 | default: | |
2ade72d7 | 684 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 685 | scm_list_1 (SCM_MAKE_CHAR (field_type))); |
0f2d19dd JB |
686 | } |
687 | ||
688 | return answer; | |
689 | } | |
1bbd0b84 | 690 | #undef FUNC_NAME |
0f2d19dd JB |
691 | |
692 | ||
a1ec6916 | 693 | SCM_DEFINE (scm_struct_set_x, "struct-set!", 3, 0, 0, |
1bbd0b84 | 694 | (SCM handle, SCM pos, SCM val), |
e3239868 DH |
695 | "Set the slot of the structure @var{handle} with index @var{pos}\n" |
696 | "to @var{val}. Signal an error if the slot can not be written\n" | |
697 | "to.") | |
1bbd0b84 | 698 | #define FUNC_NAME s_scm_struct_set_x |
0f2d19dd | 699 | { |
92c2555f | 700 | scm_t_bits * data; |
0f2d19dd | 701 | SCM layout; |
cc95e00a | 702 | size_t layout_len; |
a55c2b68 | 703 | size_t p; |
0f2d19dd | 704 | int n_fields; |
cc95e00a | 705 | const char *fields_desc; |
e51fe79c | 706 | char field_type = 0; |
0f2d19dd | 707 | |
34d19ef6 | 708 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
709 | |
710 | layout = SCM_STRUCT_LAYOUT (handle); | |
711 | data = SCM_STRUCT_DATA (handle); | |
a55c2b68 | 712 | p = scm_to_size_t (pos); |
0f2d19dd | 713 | |
cc95e00a MV |
714 | fields_desc = scm_i_symbol_chars (layout); |
715 | layout_len = scm_i_symbol_length (layout); | |
4650d115 AW |
716 | if (SCM_STRUCT_VTABLE_FLAGS (handle) & SCM_STRUCTF_LIGHT) |
717 | /* no extra words */ | |
718 | n_fields = layout_len / 2; | |
719 | else | |
720 | n_fields = data[scm_struct_i_n_words]; | |
0f2d19dd | 721 | |
34d19ef6 | 722 | SCM_ASSERT_RANGE (1, pos, p < n_fields); |
0f2d19dd | 723 | |
cc95e00a | 724 | if (p * 2 < layout_len) |
2c36c351 | 725 | { |
e51fe79c | 726 | char set_x; |
2c36c351 MD |
727 | field_type = fields_desc[p * 2]; |
728 | set_x = fields_desc [p * 2 + 1]; | |
729 | if (set_x != 'w') | |
1afff620 | 730 | SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 731 | } |
cc95e00a MV |
732 | else if (fields_desc[layout_len - 1] == 'W') |
733 | field_type = fields_desc[layout_len - 2]; | |
2c36c351 | 734 | else |
1afff620 | 735 | SCM_MISC_ERROR ("set! denied for field ~A", scm_list_1 (pos)); |
2c36c351 | 736 | |
0f2d19dd JB |
737 | switch (field_type) |
738 | { | |
739 | case 'u': | |
d8c40b9f | 740 | data[p] = SCM_NUM2ULONG (3, val); |
0f2d19dd JB |
741 | break; |
742 | ||
743 | #if 0 | |
744 | case 'i': | |
e4b265d8 | 745 | data[p] = SCM_NUM2LONG (3, val); |
0f2d19dd JB |
746 | break; |
747 | ||
748 | case 'd': | |
749 | *((double *)&(data[p])) = scm_num2dbl (val, (char *)SCM_ARG3); | |
750 | break; | |
751 | #endif | |
752 | ||
753 | case 'p': | |
d8c40b9f | 754 | data[p] = SCM_UNPACK (val); |
0f2d19dd JB |
755 | break; |
756 | ||
757 | case 's': | |
2ade72d7 | 758 | SCM_MISC_ERROR ("self fields immutable", SCM_EOL); |
0f2d19dd JB |
759 | |
760 | default: | |
2ade72d7 | 761 | SCM_MISC_ERROR ("unrecognized field type: ~S", |
1afff620 | 762 | scm_list_1 (SCM_MAKE_CHAR (field_type))); |
0f2d19dd JB |
763 | } |
764 | ||
765 | return val; | |
766 | } | |
1bbd0b84 | 767 | #undef FUNC_NAME |
0f2d19dd JB |
768 | |
769 | ||
a1ec6916 | 770 | SCM_DEFINE (scm_struct_vtable, "struct-vtable", 1, 0, 0, |
1bbd0b84 | 771 | (SCM handle), |
b380b885 | 772 | "Return the vtable structure that describes the type of @var{struct}.") |
1bbd0b84 | 773 | #define FUNC_NAME s_scm_struct_vtable |
0f2d19dd | 774 | { |
34d19ef6 | 775 | SCM_VALIDATE_STRUCT (1, handle); |
0f2d19dd JB |
776 | return SCM_STRUCT_VTABLE (handle); |
777 | } | |
1bbd0b84 | 778 | #undef FUNC_NAME |
0f2d19dd JB |
779 | |
780 | ||
a1ec6916 | 781 | SCM_DEFINE (scm_struct_vtable_tag, "struct-vtable-tag", 1, 0, 0, |
1bbd0b84 | 782 | (SCM handle), |
e3239868 | 783 | "Return the vtable tag of the structure @var{handle}.") |
1bbd0b84 | 784 | #define FUNC_NAME s_scm_struct_vtable_tag |
0f2d19dd | 785 | { |
34d19ef6 | 786 | SCM_VALIDATE_VTABLE (1, handle); |
b9bd8526 | 787 | return scm_from_ulong (((unsigned long)SCM_STRUCT_DATA (handle)) >> 3); |
98d5f601 | 788 | } |
1bbd0b84 | 789 | #undef FUNC_NAME |
98d5f601 MD |
790 | |
791 | /* {Associating names and classes with vtables} | |
792 | * | |
793 | * The name of a vtable should probably be stored as a slot. This is | |
794 | * a backward compatible solution until agreement has been achieved on | |
795 | * how to associate names with vtables. | |
796 | */ | |
797 | ||
c014a02e ML |
798 | unsigned long |
799 | scm_struct_ihashq (SCM obj, unsigned long n) | |
98d5f601 | 800 | { |
ad196599 MD |
801 | /* The length of the hash table should be a relative prime it's not |
802 | necessary to shift down the address. */ | |
f1267706 | 803 | return SCM_UNPACK (obj) % n; |
98d5f601 MD |
804 | } |
805 | ||
806 | SCM | |
807 | scm_struct_create_handle (SCM obj) | |
808 | { | |
809 | SCM handle = scm_hash_fn_create_handle_x (scm_struct_table, | |
810 | obj, | |
811 | SCM_BOOL_F, | |
812 | scm_struct_ihashq, | |
813 | scm_sloppy_assq, | |
814 | 0); | |
7888309b | 815 | if (scm_is_false (SCM_CDR (handle))) |
98d5f601 MD |
816 | SCM_SETCDR (handle, scm_cons (SCM_BOOL_F, SCM_BOOL_F)); |
817 | return handle; | |
818 | } | |
819 | ||
a1ec6916 | 820 | SCM_DEFINE (scm_struct_vtable_name, "struct-vtable-name", 1, 0, 0, |
1bbd0b84 | 821 | (SCM vtable), |
e3239868 | 822 | "Return the name of the vtable @var{vtable}.") |
1bbd0b84 | 823 | #define FUNC_NAME s_scm_struct_vtable_name |
98d5f601 | 824 | { |
34d19ef6 | 825 | SCM_VALIDATE_VTABLE (1, vtable); |
98d5f601 MD |
826 | return SCM_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable))); |
827 | } | |
1bbd0b84 | 828 | #undef FUNC_NAME |
98d5f601 | 829 | |
a1ec6916 | 830 | SCM_DEFINE (scm_set_struct_vtable_name_x, "set-struct-vtable-name!", 2, 0, 0, |
1bbd0b84 | 831 | (SCM vtable, SCM name), |
e3239868 | 832 | "Set the name of the vtable @var{vtable} to @var{name}.") |
1bbd0b84 | 833 | #define FUNC_NAME s_scm_set_struct_vtable_name_x |
98d5f601 | 834 | { |
34d19ef6 HWN |
835 | SCM_VALIDATE_VTABLE (1, vtable); |
836 | SCM_VALIDATE_SYMBOL (2, name); | |
98d5f601 MD |
837 | SCM_SET_STRUCT_TABLE_NAME (SCM_CDR (scm_struct_create_handle (vtable)), |
838 | name); | |
839 | return SCM_UNSPECIFIED; | |
0f2d19dd | 840 | } |
1bbd0b84 | 841 | #undef FUNC_NAME |
0f2d19dd JB |
842 | |
843 | ||
844 | \f | |
845 | ||
bafcafb2 | 846 | void |
1bbd0b84 | 847 | scm_print_struct (SCM exp, SCM port, scm_print_state *pstate) |
bafcafb2 | 848 | { |
7888309b | 849 | if (scm_is_true (scm_procedure_p (SCM_STRUCT_PRINTER (exp)))) |
4bfdf158 MD |
850 | scm_printer_apply (SCM_STRUCT_PRINTER (exp), exp, port, pstate); |
851 | else | |
bafcafb2 | 852 | { |
a1ae1799 MD |
853 | SCM vtable = SCM_STRUCT_VTABLE (exp); |
854 | SCM name = scm_struct_vtable_name (vtable); | |
855 | scm_puts ("#<", port); | |
7888309b | 856 | if (scm_is_true (name)) |
a1ae1799 MD |
857 | scm_display (name, port); |
858 | else | |
859 | scm_puts ("struct", port); | |
860 | scm_putc (' ', port); | |
0345e278 | 861 | scm_uintprint (SCM_UNPACK (vtable), 16, port); |
b7f3516f | 862 | scm_putc (':', port); |
0345e278 | 863 | scm_uintprint (SCM_UNPACK (exp), 16, port); |
b7f3516f | 864 | scm_putc ('>', port); |
bafcafb2 | 865 | } |
bafcafb2 | 866 | } |
1cc91f1b | 867 | |
08c880a3 MD |
868 | void |
869 | scm_struct_prehistory () | |
870 | { | |
5e67dc27 | 871 | /* Empty. */ |
08c880a3 MD |
872 | } |
873 | ||
0f2d19dd JB |
874 | void |
875 | scm_init_struct () | |
0f2d19dd | 876 | { |
98d5f601 | 877 | scm_struct_table |
e11e83f3 | 878 | = scm_permanent_object (scm_make_weak_key_hash_table (scm_from_int (31))); |
cc95e00a | 879 | required_vtable_fields = scm_from_locale_string ("prsrpw"); |
0f2d19dd | 880 | scm_permanent_object (required_vtable_fields); |
651f2cd2 KR |
881 | |
882 | scm_i_vtable_vtable_no_extra_fields = | |
883 | scm_permanent_object | |
884 | (scm_make_vtable_vtable (scm_nullstr, SCM_INUM0, SCM_EOL)); | |
885 | ||
e11e83f3 MV |
886 | scm_c_define ("vtable-index-layout", scm_from_int (scm_vtable_index_layout)); |
887 | scm_c_define ("vtable-index-vtable", scm_from_int (scm_vtable_index_vtable)); | |
86d31dfe | 888 | scm_c_define ("vtable-index-printer", |
e11e83f3 MV |
889 | scm_from_int (scm_vtable_index_printer)); |
890 | scm_c_define ("vtable-offset-user", scm_from_int (scm_vtable_offset_user)); | |
a0599745 | 891 | #include "libguile/struct.x" |
0f2d19dd | 892 | } |
89e00824 ML |
893 | |
894 | /* | |
895 | Local Variables: | |
896 | c-file-style: "gnu" | |
897 | End: | |
898 | */ |