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88e17b57 | 1 | /* Basic data types for Objective C. |
f82356d2 | 2 | Copyright (C) 1998-2014 Free Software Foundation, Inc. |
88e17b57 BE |
3 | Contributed by Ovidiu Predescu. |
4 | ||
6c82ad25 | 5 | This file is part of GCC. |
88e17b57 | 6 | |
6c82ad25 | 7 | GCC is free software; you can redistribute it and/or modify |
88e17b57 | 8 | it under the terms of the GNU General Public License as published by |
748086b7 | 9 | the Free Software Foundation; either version 3, or (at your option) |
88e17b57 BE |
10 | any later version. |
11 | ||
6c82ad25 | 12 | GCC is distributed in the hope that it will be useful, |
88e17b57 BE |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
748086b7 JJ |
17 | Under Section 7 of GPL version 3, you are granted additional |
18 | permissions described in the GCC Runtime Library Exception, version | |
19 | 3.1, as published by the Free Software Foundation. | |
88e17b57 | 20 | |
748086b7 JJ |
21 | You should have received a copy of the GNU General Public License and |
22 | a copy of the GCC Runtime Library Exception along with this program; | |
23 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
24 | <http://www.gnu.org/licenses/>. */ | |
88e17b57 | 25 | |
6dead247 | 26 | #include "objc-private/common.h" |
348a3445 | 27 | #include "objc/objc.h" |
88e17b57 | 28 | |
718a8e53 NP |
29 | #if OBJC_WITH_GC |
30 | ||
31 | #include "tconfig.h" | |
88e17b57 | 32 | #include <assert.h> |
80e4b9e5 | 33 | #include <ctype.h> /* For isdigit. */ |
88e17b57 | 34 | #include <string.h> |
63b6f9ea | 35 | #include <stdlib.h> |
80e4b9e5 NP |
36 | #include "objc/runtime.h" |
37 | #include "objc-private/module-abi-8.h" | |
88e17b57 BE |
38 | |
39 | #include <gc.h> | |
63b6f9ea | 40 | #include <limits.h> |
88e17b57 BE |
41 | |
42 | /* gc_typed.h uses the following but doesn't declare them */ | |
43 | typedef GC_word word; | |
44 | typedef GC_signed_word signed_word; | |
63b6f9ea | 45 | #define BITS_PER_WORD (CHAR_BIT * sizeof (word)) |
88e17b57 BE |
46 | |
47 | #include <gc_typed.h> | |
48 | ||
49 | /* The following functions set up in `mask` the corresponding pointers. | |
50 | The offset is incremented with the size of the type. */ | |
51 | ||
52 | #define ROUND(V, A) \ | |
40165636 RB |
53 | ({ typeof (V) __v = (V); typeof (A) __a = (A); \ |
54 | __a * ((__v+__a - 1)/__a); }) | |
88e17b57 BE |
55 | |
56 | #define SET_BIT_FOR_OFFSET(mask, offset) \ | |
40165636 | 57 | GC_set_bit (mask, offset / sizeof (void *)) |
88e17b57 BE |
58 | |
59 | /* Some prototypes */ | |
60 | static void | |
61 | __objc_gc_setup_struct (GC_bitmap mask, const char *type, int offset); | |
62 | static void | |
63 | __objc_gc_setup_union (GC_bitmap mask, const char *type, int offset); | |
64 | ||
65 | ||
66 | static void | |
67 | __objc_gc_setup_array (GC_bitmap mask, const char *type, int offset) | |
68 | { | |
40165636 | 69 | int i, len = atoi (type + 1); |
88e17b57 | 70 | |
40165636 | 71 | while (isdigit (*++type)) |
88e17b57 BE |
72 | /* do nothing */; /* skip the size of the array */ |
73 | ||
74 | switch (*type) { | |
75 | case _C_ARY_B: | |
76 | for (i = 0; i < len; i++) | |
77 | __objc_gc_setup_array (mask, type, offset); | |
78 | break; | |
79 | ||
80 | case _C_STRUCT_B: | |
81 | for (i = 0; i < len; i++) | |
82 | __objc_gc_setup_struct (mask, type, offset); | |
83 | break; | |
84 | ||
85 | case _C_UNION_B: | |
86 | for (i = 0; i < len; i++) | |
87 | __objc_gc_setup_union (mask, type, offset); | |
88 | break; | |
89 | ||
90 | default: | |
91 | break; | |
92 | } | |
93 | } | |
94 | ||
95 | static void | |
96 | __objc_gc_setup_struct (GC_bitmap mask, const char *type, int offset) | |
97 | { | |
98 | struct objc_struct_layout layout; | |
99 | unsigned int position; | |
100 | const char *mtype; | |
101 | ||
102 | objc_layout_structure (type, &layout); | |
103 | ||
104 | while (objc_layout_structure_next_member (&layout)) | |
105 | { | |
106 | BOOL gc_invisible = NO; | |
107 | ||
108 | objc_layout_structure_get_info (&layout, &position, NULL, &mtype); | |
109 | ||
110 | /* Skip the variable name */ | |
111 | if (*mtype == '"') | |
112 | { | |
113 | for (mtype++; *mtype++ != '"';) | |
114 | /* do nothing */; | |
115 | } | |
116 | ||
117 | if (*mtype == _C_GCINVISIBLE) | |
118 | { | |
119 | gc_invisible = YES; | |
120 | mtype++; | |
121 | } | |
122 | ||
123 | /* Add to position the offset of this structure */ | |
124 | position += offset; | |
125 | ||
126 | switch (*mtype) { | |
127 | case _C_ID: | |
128 | case _C_CLASS: | |
129 | case _C_SEL: | |
130 | case _C_PTR: | |
131 | case _C_CHARPTR: | |
132 | case _C_ATOM: | |
40165636 RB |
133 | if (! gc_invisible) |
134 | SET_BIT_FOR_OFFSET (mask, position); | |
88e17b57 BE |
135 | break; |
136 | ||
137 | case _C_ARY_B: | |
138 | __objc_gc_setup_array (mask, mtype, position); | |
139 | break; | |
140 | ||
141 | case _C_STRUCT_B: | |
142 | __objc_gc_setup_struct (mask, mtype, position); | |
143 | break; | |
144 | ||
145 | case _C_UNION_B: | |
146 | __objc_gc_setup_union (mask, mtype, position); | |
147 | break; | |
148 | ||
149 | default: | |
150 | break; | |
151 | } | |
152 | } | |
153 | } | |
154 | ||
155 | static void | |
156 | __objc_gc_setup_union (GC_bitmap mask, const char *type, int offset) | |
157 | { | |
158 | /* Sub-optimal, quick implementation: assume the union is made of | |
159 | pointers, set up the mask accordingly. */ | |
160 | ||
161 | int i, size, align; | |
162 | ||
163 | /* Skip the variable name */ | |
164 | if (*type == '"') | |
165 | { | |
166 | for (type++; *type++ != '"';) | |
167 | /* do nothing */; | |
168 | } | |
169 | ||
170 | size = objc_sizeof_type (type); | |
171 | align = objc_alignof_type (type); | |
172 | ||
40165636 RB |
173 | offset = ROUND (offset, align); |
174 | for (i = 0; i < size; i += sizeof (void *)) | |
88e17b57 | 175 | { |
40165636 RB |
176 | SET_BIT_FOR_OFFSET (mask, offset); |
177 | offset += sizeof (void *); | |
88e17b57 BE |
178 | } |
179 | } | |
180 | ||
181 | ||
182 | /* Iterates over the types in the structure that represents the class | |
183 | encoding and sets the bits in mask according to each ivar type. */ | |
184 | static void | |
185 | __objc_gc_type_description_from_type (GC_bitmap mask, const char *type) | |
186 | { | |
187 | struct objc_struct_layout layout; | |
188 | unsigned int offset, align; | |
189 | const char *ivar_type; | |
190 | ||
191 | objc_layout_structure (type, &layout); | |
192 | ||
193 | while (objc_layout_structure_next_member (&layout)) | |
194 | { | |
195 | BOOL gc_invisible = NO; | |
196 | ||
197 | objc_layout_structure_get_info (&layout, &offset, &align, &ivar_type); | |
198 | ||
199 | /* Skip the variable name */ | |
200 | if (*ivar_type == '"') | |
201 | { | |
202 | for (ivar_type++; *ivar_type++ != '"';) | |
203 | /* do nothing */; | |
204 | } | |
205 | ||
206 | if (*ivar_type == _C_GCINVISIBLE) | |
207 | { | |
208 | gc_invisible = YES; | |
209 | ivar_type++; | |
210 | } | |
211 | ||
212 | switch (*ivar_type) { | |
213 | case _C_ID: | |
214 | case _C_CLASS: | |
215 | case _C_SEL: | |
216 | case _C_PTR: | |
217 | case _C_CHARPTR: | |
40165636 RB |
218 | if (! gc_invisible) |
219 | SET_BIT_FOR_OFFSET (mask, offset); | |
88e17b57 BE |
220 | break; |
221 | ||
222 | case _C_ARY_B: | |
223 | __objc_gc_setup_array (mask, ivar_type, offset); | |
224 | break; | |
225 | ||
226 | case _C_STRUCT_B: | |
227 | __objc_gc_setup_struct (mask, ivar_type, offset); | |
228 | break; | |
229 | ||
230 | case _C_UNION_B: | |
231 | __objc_gc_setup_union (mask, ivar_type, offset); | |
232 | break; | |
233 | ||
234 | default: | |
235 | break; | |
236 | } | |
237 | } | |
238 | } | |
239 | ||
240 | /* Computes in *type the full type encoding of this class including | |
241 | its super classes. '*size' gives the total number of bytes allocated | |
242 | into *type, '*current' the number of bytes used so far by the | |
243 | encoding. */ | |
244 | static void | |
245 | __objc_class_structure_encoding (Class class, char **type, int *size, | |
246 | int *current) | |
247 | { | |
248 | int i, ivar_count; | |
40165636 | 249 | struct objc_ivar_list *ivars; |
88e17b57 | 250 | |
40165636 | 251 | if (! class) |
88e17b57 BE |
252 | { |
253 | strcat (*type, "{"); | |
8c3e5222 | 254 | (*current)++; |
88e17b57 BE |
255 | return; |
256 | } | |
257 | ||
258 | /* Add the type encodings of the super classes */ | |
259 | __objc_class_structure_encoding (class->super_class, type, size, current); | |
260 | ||
261 | ivars = class->ivars; | |
40165636 | 262 | if (! ivars) |
88e17b57 BE |
263 | return; |
264 | ||
265 | ivar_count = ivars->ivar_count; | |
266 | ||
267 | for (i = 0; i < ivar_count; i++) | |
268 | { | |
269 | struct objc_ivar *ivar = &(ivars->ivar_list[i]); | |
270 | const char *ivar_type = ivar->ivar_type; | |
271 | int len = strlen (ivar_type); | |
272 | ||
273 | if (*current + len + 1 >= *size) | |
274 | { | |
275 | /* Increase the size of the encoding string so that it | |
276 | contains this ivar's type. */ | |
40165636 | 277 | *size = ROUND (*current + len + 1, 10); |
88e17b57 BE |
278 | *type = objc_realloc (*type, *size); |
279 | } | |
280 | strcat (*type + *current, ivar_type); | |
281 | *current += len; | |
282 | } | |
283 | } | |
284 | ||
285 | ||
286 | /* Allocates the memory that will hold the type description for class | |
287 | and calls the __objc_class_structure_encoding that generates this | |
288 | value. */ | |
289 | void | |
290 | __objc_generate_gc_type_description (Class class) | |
291 | { | |
292 | GC_bitmap mask; | |
293 | int bits_no, size; | |
294 | int type_size = 10, current; | |
295 | char *class_structure_type; | |
296 | ||
40165636 | 297 | if (! CLS_ISCLASS (class)) |
88e17b57 BE |
298 | return; |
299 | ||
300 | /* We have to create a mask in which each bit counts for a pointer member. | |
301 | We take into consideration all the non-pointer instance variables and we | |
302 | round them up to the alignment. */ | |
303 | ||
304 | /* The number of bits in the mask is the size of an instance in bytes divided | |
305 | by the size of a pointer. */ | |
0b0b41a8 | 306 | bits_no = (ROUND (class_getInstanceSize (class), sizeof (void *)) |
40165636 RB |
307 | / sizeof (void *)); |
308 | size = ROUND (bits_no, BITS_PER_WORD) / BITS_PER_WORD; | |
88e17b57 BE |
309 | mask = objc_atomic_malloc (size * sizeof (int)); |
310 | memset (mask, 0, size * sizeof (int)); | |
311 | ||
312 | class_structure_type = objc_atomic_malloc (type_size); | |
313 | *class_structure_type = current = 0; | |
314 | __objc_class_structure_encoding (class, &class_structure_type, | |
315 | &type_size, ¤t); | |
316 | if (current + 1 == type_size) | |
317 | class_structure_type = objc_realloc (class_structure_type, ++type_size); | |
318 | strcat (class_structure_type + current, "}"); | |
041dea56 OP |
319 | #ifdef DEBUG |
320 | printf ("type description for '%s' is %s\n", class->name, class_structure_type); | |
321 | #endif | |
88e17b57 BE |
322 | |
323 | __objc_gc_type_description_from_type (mask, class_structure_type); | |
324 | objc_free (class_structure_type); | |
325 | ||
88e17b57 BE |
326 | #ifdef DEBUG |
327 | printf (" mask for '%s', type '%s' (bits %d, mask size %d) is:", | |
328 | class_structure_type, class->name, bits_no, size); | |
329 | { | |
330 | int i; | |
331 | for (i = 0; i < size; i++) | |
332 | printf (" %lx", mask[i]); | |
333 | } | |
334 | puts (""); | |
335 | #endif | |
336 | ||
40165636 | 337 | class->gc_object_type = (void *) GC_make_descriptor (mask, bits_no); |
88e17b57 BE |
338 | } |
339 | ||
340 | ||
341 | /* Returns YES if type denotes a pointer type, NO otherwise */ | |
342 | static inline BOOL | |
343 | __objc_ivar_pointer (const char *type) | |
344 | { | |
345 | type = objc_skip_type_qualifiers (type); | |
346 | ||
347 | return (*type == _C_ID | |
348 | || *type == _C_CLASS | |
349 | || *type == _C_SEL | |
350 | || *type == _C_PTR | |
351 | || *type == _C_CHARPTR | |
352 | || *type == _C_ATOM); | |
353 | } | |
354 | ||
355 | ||
356 | /* Mark the instance variable whose name is given by ivarname as a | |
357 | weak pointer (a pointer hidden to the garbage collector) if | |
358 | gc_invisible is true. If gc_invisible is false it unmarks the | |
359 | instance variable and makes it a normal pointer, visible to the | |
360 | garbage collector. | |
361 | ||
362 | This operation only makes sense on instance variables that are | |
363 | pointers. */ | |
364 | void | |
40165636 | 365 | class_ivar_set_gcinvisible (Class class, const char *ivarname, |
88e17b57 BE |
366 | BOOL gc_invisible) |
367 | { | |
368 | int i, ivar_count; | |
40165636 | 369 | struct objc_ivar_list *ivars; |
88e17b57 | 370 | |
40165636 | 371 | if (! class || ! ivarname) |
88e17b57 BE |
372 | return; |
373 | ||
374 | ivars = class->ivars; | |
40165636 | 375 | if (! ivars) |
88e17b57 BE |
376 | return; |
377 | ||
378 | ivar_count = ivars->ivar_count; | |
379 | ||
380 | for (i = 0; i < ivar_count; i++) | |
381 | { | |
382 | struct objc_ivar *ivar = &(ivars->ivar_list[i]); | |
383 | const char *type; | |
384 | ||
40165636 | 385 | if (! ivar->ivar_name || strcmp (ivar->ivar_name, ivarname)) |
88e17b57 BE |
386 | continue; |
387 | ||
388 | assert (ivar->ivar_type); | |
389 | type = ivar->ivar_type; | |
390 | ||
391 | /* Skip the variable name */ | |
392 | if (*type == '"') | |
393 | { | |
394 | for (type++; *type++ != '"';) | |
395 | /* do nothing */; | |
396 | } | |
397 | ||
398 | if (*type == _C_GCINVISIBLE) | |
399 | { | |
400 | char *new_type; | |
801a91f9 | 401 | size_t len; |
88e17b57 | 402 | |
40165636 | 403 | if (gc_invisible || ! __objc_ivar_pointer (type)) |
88e17b57 BE |
404 | return; /* The type of the variable already matches the |
405 | requested gc_invisible type */ | |
406 | ||
801a91f9 DA |
407 | /* The variable is gc_invisible so we make it gc visible. */ |
408 | new_type = objc_atomic_malloc (strlen(ivar->ivar_type)); | |
409 | len = (type - ivar->ivar_type); | |
410 | memcpy (new_type, ivar->ivar_type, len); | |
411 | new_type[len] = 0; | |
88e17b57 BE |
412 | strcat (new_type, type + 1); |
413 | ivar->ivar_type = new_type; | |
414 | } | |
415 | else | |
416 | { | |
417 | char *new_type; | |
801a91f9 | 418 | size_t len; |
88e17b57 | 419 | |
40165636 | 420 | if (! gc_invisible || ! __objc_ivar_pointer (type)) |
88e17b57 BE |
421 | return; /* The type of the variable already matches the |
422 | requested gc_invisible type */ | |
423 | ||
801a91f9 DA |
424 | /* The variable is gc visible so we make it gc_invisible. */ |
425 | new_type = objc_malloc (strlen(ivar->ivar_type) + 2); | |
55b21c7a RFM |
426 | |
427 | /* Copy the variable name. */ | |
801a91f9 DA |
428 | len = (type - ivar->ivar_type); |
429 | memcpy (new_type, ivar->ivar_type, len); | |
55b21c7a RFM |
430 | /* Add '!'. */ |
431 | new_type[len++] = _C_GCINVISIBLE; | |
432 | /* Copy the original types. */ | |
433 | strcpy (new_type + len, type); | |
434 | ||
88e17b57 BE |
435 | ivar->ivar_type = new_type; |
436 | } | |
437 | ||
438 | __objc_generate_gc_type_description (class); | |
439 | return; | |
440 | } | |
441 | ||
442 | /* Search the instance variable in the superclasses */ | |
443 | class_ivar_set_gcinvisible (class->super_class, ivarname, gc_invisible); | |
444 | } | |
445 | ||
446 | #else /* !OBJC_WITH_GC */ | |
447 | ||
448 | void | |
8f8c44cb | 449 | __objc_generate_gc_type_description (Class class __attribute__ ((__unused__))) |
88e17b57 BE |
450 | { |
451 | } | |
452 | ||
8f8c44cb | 453 | void class_ivar_set_gcinvisible (Class class __attribute__ ((__unused__)), |
40165636 | 454 | const char *ivarname __attribute__ ((__unused__)), |
8f8c44cb | 455 | BOOL gc_invisible __attribute__ ((__unused__))) |
88e17b57 BE |
456 | { |
457 | } | |
458 | ||
459 | #endif /* OBJC_WITH_GC */ |