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88e17b57 | 1 | /* Basic data types for Objective C. |
748086b7 | 2 | Copyright (C) 1998, 2002, 2004, 2005, 2006, 2009 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" |
bce1b489 | 27 | #include "tconfig.h" |
348a3445 DA |
28 | #include "objc/objc.h" |
29 | #include "objc/encoding.h" | |
88e17b57 BE |
30 | |
31 | #include <assert.h> | |
32 | #include <string.h> | |
63b6f9ea | 33 | #include <stdlib.h> |
88e17b57 BE |
34 | |
35 | #if OBJC_WITH_GC | |
36 | ||
37 | #include <gc.h> | |
63b6f9ea | 38 | #include <limits.h> |
88e17b57 BE |
39 | |
40 | /* gc_typed.h uses the following but doesn't declare them */ | |
41 | typedef GC_word word; | |
42 | typedef GC_signed_word signed_word; | |
63b6f9ea | 43 | #define BITS_PER_WORD (CHAR_BIT * sizeof (word)) |
88e17b57 BE |
44 | |
45 | #include <gc_typed.h> | |
46 | ||
47 | /* The following functions set up in `mask` the corresponding pointers. | |
48 | The offset is incremented with the size of the type. */ | |
49 | ||
50 | #define ROUND(V, A) \ | |
40165636 RB |
51 | ({ typeof (V) __v = (V); typeof (A) __a = (A); \ |
52 | __a * ((__v+__a - 1)/__a); }) | |
88e17b57 BE |
53 | |
54 | #define SET_BIT_FOR_OFFSET(mask, offset) \ | |
40165636 | 55 | GC_set_bit (mask, offset / sizeof (void *)) |
88e17b57 BE |
56 | |
57 | /* Some prototypes */ | |
58 | static void | |
59 | __objc_gc_setup_struct (GC_bitmap mask, const char *type, int offset); | |
60 | static void | |
61 | __objc_gc_setup_union (GC_bitmap mask, const char *type, int offset); | |
62 | ||
63 | ||
64 | static void | |
65 | __objc_gc_setup_array (GC_bitmap mask, const char *type, int offset) | |
66 | { | |
40165636 | 67 | int i, len = atoi (type + 1); |
88e17b57 | 68 | |
40165636 | 69 | while (isdigit (*++type)) |
88e17b57 BE |
70 | /* do nothing */; /* skip the size of the array */ |
71 | ||
72 | switch (*type) { | |
73 | case _C_ARY_B: | |
74 | for (i = 0; i < len; i++) | |
75 | __objc_gc_setup_array (mask, type, offset); | |
76 | break; | |
77 | ||
78 | case _C_STRUCT_B: | |
79 | for (i = 0; i < len; i++) | |
80 | __objc_gc_setup_struct (mask, type, offset); | |
81 | break; | |
82 | ||
83 | case _C_UNION_B: | |
84 | for (i = 0; i < len; i++) | |
85 | __objc_gc_setup_union (mask, type, offset); | |
86 | break; | |
87 | ||
88 | default: | |
89 | break; | |
90 | } | |
91 | } | |
92 | ||
93 | static void | |
94 | __objc_gc_setup_struct (GC_bitmap mask, const char *type, int offset) | |
95 | { | |
96 | struct objc_struct_layout layout; | |
97 | unsigned int position; | |
98 | const char *mtype; | |
99 | ||
100 | objc_layout_structure (type, &layout); | |
101 | ||
102 | while (objc_layout_structure_next_member (&layout)) | |
103 | { | |
104 | BOOL gc_invisible = NO; | |
105 | ||
106 | objc_layout_structure_get_info (&layout, &position, NULL, &mtype); | |
107 | ||
108 | /* Skip the variable name */ | |
109 | if (*mtype == '"') | |
110 | { | |
111 | for (mtype++; *mtype++ != '"';) | |
112 | /* do nothing */; | |
113 | } | |
114 | ||
115 | if (*mtype == _C_GCINVISIBLE) | |
116 | { | |
117 | gc_invisible = YES; | |
118 | mtype++; | |
119 | } | |
120 | ||
121 | /* Add to position the offset of this structure */ | |
122 | position += offset; | |
123 | ||
124 | switch (*mtype) { | |
125 | case _C_ID: | |
126 | case _C_CLASS: | |
127 | case _C_SEL: | |
128 | case _C_PTR: | |
129 | case _C_CHARPTR: | |
130 | case _C_ATOM: | |
40165636 RB |
131 | if (! gc_invisible) |
132 | SET_BIT_FOR_OFFSET (mask, position); | |
88e17b57 BE |
133 | break; |
134 | ||
135 | case _C_ARY_B: | |
136 | __objc_gc_setup_array (mask, mtype, position); | |
137 | break; | |
138 | ||
139 | case _C_STRUCT_B: | |
140 | __objc_gc_setup_struct (mask, mtype, position); | |
141 | break; | |
142 | ||
143 | case _C_UNION_B: | |
144 | __objc_gc_setup_union (mask, mtype, position); | |
145 | break; | |
146 | ||
147 | default: | |
148 | break; | |
149 | } | |
150 | } | |
151 | } | |
152 | ||
153 | static void | |
154 | __objc_gc_setup_union (GC_bitmap mask, const char *type, int offset) | |
155 | { | |
156 | /* Sub-optimal, quick implementation: assume the union is made of | |
157 | pointers, set up the mask accordingly. */ | |
158 | ||
159 | int i, size, align; | |
160 | ||
161 | /* Skip the variable name */ | |
162 | if (*type == '"') | |
163 | { | |
164 | for (type++; *type++ != '"';) | |
165 | /* do nothing */; | |
166 | } | |
167 | ||
168 | size = objc_sizeof_type (type); | |
169 | align = objc_alignof_type (type); | |
170 | ||
40165636 RB |
171 | offset = ROUND (offset, align); |
172 | for (i = 0; i < size; i += sizeof (void *)) | |
88e17b57 | 173 | { |
40165636 RB |
174 | SET_BIT_FOR_OFFSET (mask, offset); |
175 | offset += sizeof (void *); | |
88e17b57 BE |
176 | } |
177 | } | |
178 | ||
179 | ||
180 | /* Iterates over the types in the structure that represents the class | |
181 | encoding and sets the bits in mask according to each ivar type. */ | |
182 | static void | |
183 | __objc_gc_type_description_from_type (GC_bitmap mask, const char *type) | |
184 | { | |
185 | struct objc_struct_layout layout; | |
186 | unsigned int offset, align; | |
187 | const char *ivar_type; | |
188 | ||
189 | objc_layout_structure (type, &layout); | |
190 | ||
191 | while (objc_layout_structure_next_member (&layout)) | |
192 | { | |
193 | BOOL gc_invisible = NO; | |
194 | ||
195 | objc_layout_structure_get_info (&layout, &offset, &align, &ivar_type); | |
196 | ||
197 | /* Skip the variable name */ | |
198 | if (*ivar_type == '"') | |
199 | { | |
200 | for (ivar_type++; *ivar_type++ != '"';) | |
201 | /* do nothing */; | |
202 | } | |
203 | ||
204 | if (*ivar_type == _C_GCINVISIBLE) | |
205 | { | |
206 | gc_invisible = YES; | |
207 | ivar_type++; | |
208 | } | |
209 | ||
210 | switch (*ivar_type) { | |
211 | case _C_ID: | |
212 | case _C_CLASS: | |
213 | case _C_SEL: | |
214 | case _C_PTR: | |
215 | case _C_CHARPTR: | |
40165636 RB |
216 | if (! gc_invisible) |
217 | SET_BIT_FOR_OFFSET (mask, offset); | |
88e17b57 BE |
218 | break; |
219 | ||
220 | case _C_ARY_B: | |
221 | __objc_gc_setup_array (mask, ivar_type, offset); | |
222 | break; | |
223 | ||
224 | case _C_STRUCT_B: | |
225 | __objc_gc_setup_struct (mask, ivar_type, offset); | |
226 | break; | |
227 | ||
228 | case _C_UNION_B: | |
229 | __objc_gc_setup_union (mask, ivar_type, offset); | |
230 | break; | |
231 | ||
232 | default: | |
233 | break; | |
234 | } | |
235 | } | |
236 | } | |
237 | ||
238 | /* Computes in *type the full type encoding of this class including | |
239 | its super classes. '*size' gives the total number of bytes allocated | |
240 | into *type, '*current' the number of bytes used so far by the | |
241 | encoding. */ | |
242 | static void | |
243 | __objc_class_structure_encoding (Class class, char **type, int *size, | |
244 | int *current) | |
245 | { | |
246 | int i, ivar_count; | |
40165636 | 247 | struct objc_ivar_list *ivars; |
88e17b57 | 248 | |
40165636 | 249 | if (! class) |
88e17b57 BE |
250 | { |
251 | strcat (*type, "{"); | |
8c3e5222 | 252 | (*current)++; |
88e17b57 BE |
253 | return; |
254 | } | |
255 | ||
256 | /* Add the type encodings of the super classes */ | |
257 | __objc_class_structure_encoding (class->super_class, type, size, current); | |
258 | ||
259 | ivars = class->ivars; | |
40165636 | 260 | if (! ivars) |
88e17b57 BE |
261 | return; |
262 | ||
263 | ivar_count = ivars->ivar_count; | |
264 | ||
265 | for (i = 0; i < ivar_count; i++) | |
266 | { | |
267 | struct objc_ivar *ivar = &(ivars->ivar_list[i]); | |
268 | const char *ivar_type = ivar->ivar_type; | |
269 | int len = strlen (ivar_type); | |
270 | ||
271 | if (*current + len + 1 >= *size) | |
272 | { | |
273 | /* Increase the size of the encoding string so that it | |
274 | contains this ivar's type. */ | |
40165636 | 275 | *size = ROUND (*current + len + 1, 10); |
88e17b57 BE |
276 | *type = objc_realloc (*type, *size); |
277 | } | |
278 | strcat (*type + *current, ivar_type); | |
279 | *current += len; | |
280 | } | |
281 | } | |
282 | ||
283 | ||
284 | /* Allocates the memory that will hold the type description for class | |
285 | and calls the __objc_class_structure_encoding that generates this | |
286 | value. */ | |
287 | void | |
288 | __objc_generate_gc_type_description (Class class) | |
289 | { | |
290 | GC_bitmap mask; | |
291 | int bits_no, size; | |
292 | int type_size = 10, current; | |
293 | char *class_structure_type; | |
294 | ||
40165636 | 295 | if (! CLS_ISCLASS (class)) |
88e17b57 BE |
296 | return; |
297 | ||
298 | /* We have to create a mask in which each bit counts for a pointer member. | |
299 | We take into consideration all the non-pointer instance variables and we | |
300 | round them up to the alignment. */ | |
301 | ||
302 | /* The number of bits in the mask is the size of an instance in bytes divided | |
303 | by the size of a pointer. */ | |
40165636 RB |
304 | bits_no = (ROUND (class_get_instance_size (class), sizeof (void *)) |
305 | / sizeof (void *)); | |
306 | size = ROUND (bits_no, BITS_PER_WORD) / BITS_PER_WORD; | |
88e17b57 BE |
307 | mask = objc_atomic_malloc (size * sizeof (int)); |
308 | memset (mask, 0, size * sizeof (int)); | |
309 | ||
310 | class_structure_type = objc_atomic_malloc (type_size); | |
311 | *class_structure_type = current = 0; | |
312 | __objc_class_structure_encoding (class, &class_structure_type, | |
313 | &type_size, ¤t); | |
314 | if (current + 1 == type_size) | |
315 | class_structure_type = objc_realloc (class_structure_type, ++type_size); | |
316 | strcat (class_structure_type + current, "}"); | |
041dea56 OP |
317 | #ifdef DEBUG |
318 | printf ("type description for '%s' is %s\n", class->name, class_structure_type); | |
319 | #endif | |
88e17b57 BE |
320 | |
321 | __objc_gc_type_description_from_type (mask, class_structure_type); | |
322 | objc_free (class_structure_type); | |
323 | ||
88e17b57 BE |
324 | #ifdef DEBUG |
325 | printf (" mask for '%s', type '%s' (bits %d, mask size %d) is:", | |
326 | class_structure_type, class->name, bits_no, size); | |
327 | { | |
328 | int i; | |
329 | for (i = 0; i < size; i++) | |
330 | printf (" %lx", mask[i]); | |
331 | } | |
332 | puts (""); | |
333 | #endif | |
334 | ||
40165636 | 335 | class->gc_object_type = (void *) GC_make_descriptor (mask, bits_no); |
88e17b57 BE |
336 | } |
337 | ||
338 | ||
339 | /* Returns YES if type denotes a pointer type, NO otherwise */ | |
340 | static inline BOOL | |
341 | __objc_ivar_pointer (const char *type) | |
342 | { | |
343 | type = objc_skip_type_qualifiers (type); | |
344 | ||
345 | return (*type == _C_ID | |
346 | || *type == _C_CLASS | |
347 | || *type == _C_SEL | |
348 | || *type == _C_PTR | |
349 | || *type == _C_CHARPTR | |
350 | || *type == _C_ATOM); | |
351 | } | |
352 | ||
353 | ||
354 | /* Mark the instance variable whose name is given by ivarname as a | |
355 | weak pointer (a pointer hidden to the garbage collector) if | |
356 | gc_invisible is true. If gc_invisible is false it unmarks the | |
357 | instance variable and makes it a normal pointer, visible to the | |
358 | garbage collector. | |
359 | ||
360 | This operation only makes sense on instance variables that are | |
361 | pointers. */ | |
362 | void | |
40165636 | 363 | class_ivar_set_gcinvisible (Class class, const char *ivarname, |
88e17b57 BE |
364 | BOOL gc_invisible) |
365 | { | |
366 | int i, ivar_count; | |
40165636 | 367 | struct objc_ivar_list *ivars; |
88e17b57 | 368 | |
40165636 | 369 | if (! class || ! ivarname) |
88e17b57 BE |
370 | return; |
371 | ||
372 | ivars = class->ivars; | |
40165636 | 373 | if (! ivars) |
88e17b57 BE |
374 | return; |
375 | ||
376 | ivar_count = ivars->ivar_count; | |
377 | ||
378 | for (i = 0; i < ivar_count; i++) | |
379 | { | |
380 | struct objc_ivar *ivar = &(ivars->ivar_list[i]); | |
381 | const char *type; | |
382 | ||
40165636 | 383 | if (! ivar->ivar_name || strcmp (ivar->ivar_name, ivarname)) |
88e17b57 BE |
384 | continue; |
385 | ||
386 | assert (ivar->ivar_type); | |
387 | type = ivar->ivar_type; | |
388 | ||
389 | /* Skip the variable name */ | |
390 | if (*type == '"') | |
391 | { | |
392 | for (type++; *type++ != '"';) | |
393 | /* do nothing */; | |
394 | } | |
395 | ||
396 | if (*type == _C_GCINVISIBLE) | |
397 | { | |
398 | char *new_type; | |
801a91f9 | 399 | size_t len; |
88e17b57 | 400 | |
40165636 | 401 | if (gc_invisible || ! __objc_ivar_pointer (type)) |
88e17b57 BE |
402 | return; /* The type of the variable already matches the |
403 | requested gc_invisible type */ | |
404 | ||
801a91f9 DA |
405 | /* The variable is gc_invisible so we make it gc visible. */ |
406 | new_type = objc_atomic_malloc (strlen(ivar->ivar_type)); | |
407 | len = (type - ivar->ivar_type); | |
408 | memcpy (new_type, ivar->ivar_type, len); | |
409 | new_type[len] = 0; | |
88e17b57 BE |
410 | strcat (new_type, type + 1); |
411 | ivar->ivar_type = new_type; | |
412 | } | |
413 | else | |
414 | { | |
415 | char *new_type; | |
801a91f9 | 416 | size_t len; |
88e17b57 | 417 | |
40165636 | 418 | if (! gc_invisible || ! __objc_ivar_pointer (type)) |
88e17b57 BE |
419 | return; /* The type of the variable already matches the |
420 | requested gc_invisible type */ | |
421 | ||
801a91f9 DA |
422 | /* The variable is gc visible so we make it gc_invisible. */ |
423 | new_type = objc_malloc (strlen(ivar->ivar_type) + 2); | |
424 | len = (type - ivar->ivar_type); | |
425 | memcpy (new_type, ivar->ivar_type, len); | |
426 | new_type[len] = 0; | |
88e17b57 BE |
427 | strcat (new_type, "!"); |
428 | strcat (new_type, type); | |
429 | ivar->ivar_type = new_type; | |
430 | } | |
431 | ||
432 | __objc_generate_gc_type_description (class); | |
433 | return; | |
434 | } | |
435 | ||
436 | /* Search the instance variable in the superclasses */ | |
437 | class_ivar_set_gcinvisible (class->super_class, ivarname, gc_invisible); | |
438 | } | |
439 | ||
440 | #else /* !OBJC_WITH_GC */ | |
441 | ||
442 | void | |
8f8c44cb | 443 | __objc_generate_gc_type_description (Class class __attribute__ ((__unused__))) |
88e17b57 BE |
444 | { |
445 | } | |
446 | ||
8f8c44cb | 447 | void class_ivar_set_gcinvisible (Class class __attribute__ ((__unused__)), |
40165636 | 448 | const char *ivarname __attribute__ ((__unused__)), |
8f8c44cb | 449 | BOOL gc_invisible __attribute__ ((__unused__))) |
88e17b57 BE |
450 | { |
451 | } | |
452 | ||
453 | #endif /* OBJC_WITH_GC */ |