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d60bb9a0 C |
1 | /* Garbage collection primitives for GNU C++. |
2 | Copyright (C) 1992 Free Software Foundation, Inc. | |
3 | Contributed by Michael Tiemann (tiemann@cygnus.com) | |
4 | ||
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
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 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | ||
22 | #include "config.h" | |
23 | #include "tree.h" | |
24 | #include "cp-tree.h" | |
25 | #include "flags.h" | |
26 | ||
27 | #define NULL 0 | |
28 | ||
29 | extern tree build_t_desc_overload (); | |
30 | ||
31 | /* This is the function decl for the (pseudo-builtin) __gc_protect | |
32 | function. Args are (class *value, int index); Returns value. */ | |
33 | tree gc_protect_fndecl; | |
34 | ||
35 | /* This is the function decl for the (pseudo-builtin) __gc_unprotect | |
36 | function. Args are (int index); void return. */ | |
37 | tree gc_unprotect_fndecl; | |
38 | ||
39 | /* This is the function decl for the (pseudo-builtin) __gc_push | |
40 | function. Args are (int length); void return. */ | |
41 | tree gc_push_fndecl; | |
42 | ||
43 | /* This is the function decl for the (pseudo-builtin) __gc_pop | |
44 | function. Args are void; void return. */ | |
45 | tree gc_pop_fndecl; | |
46 | ||
47 | /* Special integers that are used to represent bits in gc-safe objects. */ | |
48 | tree gc_nonobject; | |
49 | tree gc_visible; | |
50 | tree gc_white; | |
51 | tree gc_offwhite; | |
52 | tree gc_grey; | |
53 | tree gc_black; | |
54 | \f | |
55 | /* Predicate that returns non-zero if TYPE needs some kind of | |
56 | entry for the GC. Returns zero otherwise. */ | |
57 | int | |
58 | type_needs_gc_entry (type) | |
59 | tree type; | |
60 | { | |
61 | tree ttype = type; | |
62 | ||
63 | if (! flag_gc || type == error_mark_node) | |
64 | return 0; | |
65 | ||
66 | /* Aggregate types need gc entries if any of their members | |
67 | need gc entries. */ | |
68 | if (IS_AGGR_TYPE (type)) | |
69 | { | |
70 | tree binfos; | |
71 | tree fields = TYPE_FIELDS (type); | |
72 | int i; | |
73 | ||
74 | /* We don't care about certain pointers. Pointers | |
75 | to virtual baseclasses are always up front. We also | |
76 | cull out virtual function table pointers because it's | |
77 | easy, and it simplifies the logic.*/ | |
78 | while (fields | |
79 | && (DECL_NAME (fields) == NULL_TREE | |
80 | || VFIELD_NAME_P (DECL_NAME (fields)) | |
81 | || VBASE_NAME_P (DECL_NAME (fields)) | |
82 | || !strcmp (IDENTIFIER_POINTER (DECL_NAME (fields)), "__bits"))) | |
83 | fields = TREE_CHAIN (fields); | |
84 | ||
85 | while (fields) | |
86 | { | |
87 | if (type_needs_gc_entry (TREE_TYPE (fields))) | |
88 | return 1; | |
89 | fields = TREE_CHAIN (fields); | |
90 | } | |
91 | ||
92 | binfos = TYPE_BINFO_BASETYPES (type); | |
93 | if (binfos) | |
94 | for (i = TREE_VEC_LENGTH (binfos)-1; i >= 0; i--) | |
95 | if (type_needs_gc_entry (BINFO_TYPE (TREE_VEC_ELT (binfos, i)))) | |
96 | return 1; | |
97 | ||
98 | return 0; | |
99 | } | |
100 | ||
101 | while (TREE_CODE (ttype) == ARRAY_TYPE | |
102 | && TREE_CODE (TREE_TYPE (ttype)) == ARRAY_TYPE) | |
103 | ttype = TREE_TYPE (ttype); | |
104 | if ((TREE_CODE (ttype) == POINTER_TYPE | |
105 | || TREE_CODE (ttype) == ARRAY_TYPE | |
106 | || TREE_CODE (ttype) == REFERENCE_TYPE) | |
107 | && IS_AGGR_TYPE (TREE_TYPE (ttype)) | |
108 | && CLASSTYPE_DOSSIER (TREE_TYPE (ttype))) | |
109 | return 1; | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | /* Predicate that returns non-zero iff FROM is safe from the GC. | |
115 | ||
116 | If TO is nonzero, it means we know that FROM is being stored | |
117 | in TO, which make make it safe. */ | |
118 | int | |
119 | value_safe_from_gc (to, from) | |
120 | tree to, from; | |
121 | { | |
122 | /* First, return non-zero for easy cases: parameters, | |
123 | static variables. */ | |
124 | if (TREE_CODE (from) == PARM_DECL | |
125 | || (TREE_CODE (from) == VAR_DECL | |
126 | && TREE_STATIC (from))) | |
127 | return 1; | |
128 | ||
129 | /* If something has its address taken, it cannot be | |
130 | in the heap, so it doesn't need to be protected. */ | |
131 | if (TREE_CODE (from) == ADDR_EXPR || TREE_REFERENCE_EXPR (from)) | |
132 | return 1; | |
133 | ||
134 | /* If we are storing into a static variable, then what | |
135 | we store will be safe from the gc. */ | |
136 | if (to && TREE_CODE (to) == VAR_DECL | |
137 | && TREE_STATIC (to)) | |
138 | return 1; | |
139 | ||
140 | /* Now recurse on structure of FROM. */ | |
141 | switch (TREE_CODE (from)) | |
142 | { | |
143 | case COMPONENT_REF: | |
144 | /* These guys are special, and safe. */ | |
145 | if (TREE_CODE (TREE_OPERAND (from, 1)) == FIELD_DECL | |
146 | && (VFIELD_NAME_P (DECL_NAME (TREE_OPERAND (from, 1))) | |
147 | || VBASE_NAME_P (DECL_NAME (TREE_OPERAND (from, 1))))) | |
148 | return 1; | |
149 | /* fall through... */ | |
150 | case NOP_EXPR: | |
151 | case CONVERT_EXPR: | |
152 | case NON_LVALUE_EXPR: | |
153 | case WITH_CLEANUP_EXPR: | |
154 | case SAVE_EXPR: | |
155 | case PREDECREMENT_EXPR: | |
156 | case PREINCREMENT_EXPR: | |
157 | case POSTDECREMENT_EXPR: | |
158 | case POSTINCREMENT_EXPR: | |
159 | if (value_safe_from_gc (to, TREE_OPERAND (from, 0))) | |
160 | return 1; | |
161 | break; | |
162 | ||
163 | case VAR_DECL: | |
164 | case PARM_DECL: | |
165 | /* We can safely pass these things as parameters to functions. */ | |
166 | if (to == 0) | |
167 | return 1; | |
168 | ||
169 | case ARRAY_REF: | |
170 | case INDIRECT_REF: | |
171 | case RESULT_DECL: | |
172 | case OFFSET_REF: | |
173 | case CALL_EXPR: | |
174 | case METHOD_CALL_EXPR: | |
175 | break; | |
176 | ||
177 | case COMPOUND_EXPR: | |
178 | case TARGET_EXPR: | |
179 | if (value_safe_from_gc (to, TREE_OPERAND (from, 1))) | |
180 | return 1; | |
181 | break; | |
182 | ||
183 | case COND_EXPR: | |
184 | if (value_safe_from_gc (to, TREE_OPERAND (from, 1)) | |
185 | && value_safe_from_gc (to, TREE_OPERAND (from, 2))) | |
186 | return 1; | |
187 | break; | |
188 | ||
189 | case PLUS_EXPR: | |
190 | case MINUS_EXPR: | |
191 | if ((type_needs_gc_entry (TREE_TYPE (TREE_OPERAND (from, 0))) | |
192 | || value_safe_from_gc (to, TREE_OPERAND (from, 0))) | |
193 | && (type_needs_gc_entry (TREE_TYPE (TREE_OPERAND (from, 1))) == 0 | |
194 | || value_safe_from_gc (to, TREE_OPERAND (from, 1)))) | |
195 | return 1; | |
196 | break; | |
197 | ||
198 | case RTL_EXPR: | |
199 | /* Every time we build an RTL_EXPR in the front-end, we must | |
200 | ensure that everything in it is safe from the garbage collector. | |
201 | ??? This has only been done for `build_new'. */ | |
202 | return 1; | |
203 | ||
204 | default: | |
205 | my_friendly_abort (41); | |
206 | } | |
207 | ||
208 | if (to == 0) | |
209 | return 0; | |
210 | ||
211 | /* FROM wasn't safe. But other properties of TO might make it safe. */ | |
212 | switch (TREE_CODE (to)) | |
213 | { | |
214 | case VAR_DECL: | |
215 | case PARM_DECL: | |
216 | /* We already culled out static VAR_DECLs above. */ | |
217 | return 0; | |
218 | ||
219 | case COMPONENT_REF: | |
220 | /* These guys are special, and safe. */ | |
221 | if (TREE_CODE (TREE_OPERAND (to, 1)) == FIELD_DECL | |
222 | && (VFIELD_NAME_P (DECL_NAME (TREE_OPERAND (to, 1))) | |
223 | || VBASE_NAME_P (DECL_NAME (TREE_OPERAND (to, 1))))) | |
224 | return 1; | |
225 | /* fall through... */ | |
226 | ||
227 | case NOP_EXPR: | |
228 | case NON_LVALUE_EXPR: | |
229 | case WITH_CLEANUP_EXPR: | |
230 | case SAVE_EXPR: | |
231 | case PREDECREMENT_EXPR: | |
232 | case PREINCREMENT_EXPR: | |
233 | case POSTDECREMENT_EXPR: | |
234 | case POSTINCREMENT_EXPR: | |
235 | return value_safe_from_gc (TREE_OPERAND (to, 0), from); | |
236 | ||
237 | case COMPOUND_EXPR: | |
238 | case TARGET_EXPR: | |
239 | return value_safe_from_gc (TREE_OPERAND (to, 1), from); | |
240 | ||
241 | case COND_EXPR: | |
242 | return (value_safe_from_gc (TREE_OPERAND (to, 1), from) | |
243 | && value_safe_from_gc (TREE_OPERAND (to, 2), from)); | |
244 | ||
245 | case INDIRECT_REF: | |
246 | case ARRAY_REF: | |
247 | /* This used to be 0, but our current restricted model | |
248 | allows this to be 1. We'll never get arrays this way. */ | |
249 | return 1; | |
250 | ||
251 | default: | |
252 | my_friendly_abort (42); | |
253 | } | |
254 | ||
255 | /* Catch-all case is that TO/FROM is not safe. */ | |
256 | return 0; | |
257 | } | |
258 | \f | |
259 | /* Function to build a static GC entry for DECL. TYPE is DECL's type. | |
260 | ||
261 | For objects of type `class *', this is just an entry in the | |
262 | static vector __PTR_LIST__. | |
263 | ||
264 | For objects of type `class[]', this requires building an entry | |
265 | in the static vector __ARR_LIST__. | |
266 | ||
267 | For aggregates, this records all fields of type `class *' | |
268 | and `class[]' in the respective lists above. */ | |
269 | void | |
270 | build_static_gc_entry (decl, type) | |
271 | tree decl; | |
272 | tree type; | |
273 | { | |
274 | /* Now, figure out what sort of entry to build. */ | |
275 | if (TREE_CODE (type) == POINTER_TYPE | |
276 | || TREE_CODE (type) == REFERENCE_TYPE) | |
277 | assemble_gc_entry (IDENTIFIER_POINTER (DECL_NAME (decl))); | |
278 | else if (TREE_CODE (type) == RECORD_TYPE) | |
279 | { | |
280 | tree ref = get_temp_name (build_reference_type (type), 1); | |
281 | DECL_INITIAL (ref) = build1 (ADDR_EXPR, TREE_TYPE (ref), decl); | |
282 | TREE_CONSTANT (DECL_INITIAL (ref)) = 1; | |
283 | finish_decl (ref, DECL_INITIAL (ref), 0, 0); | |
284 | } | |
285 | else | |
286 | { | |
287 | /* Not yet implemented. | |
288 | ||
289 | Cons up a static variable that holds address and length info | |
290 | and add that to ___ARR_LIST__. */ | |
291 | my_friendly_abort (43); | |
292 | } | |
293 | } | |
294 | \f | |
295 | /* Protect FROM from the GC, assuming FROM is going to be | |
296 | stored into TO. We handle three cases for TO here: | |
297 | ||
298 | case 1: TO is a stack variable. | |
299 | case 2: TO is zero (which means it is a parameter). | |
300 | case 3: TO is a return value. */ | |
301 | ||
302 | tree | |
303 | protect_value_from_gc (to, from) | |
304 | tree to, from; | |
305 | { | |
306 | if (to == 0) | |
307 | { | |
308 | tree cleanup; | |
309 | ||
310 | to = get_temp_regvar (TREE_TYPE (from), from); | |
311 | ||
312 | /* Convert from integer to list form since we'll use it twice. */ | |
313 | DECL_GC_OFFSET (to) = build_tree_list (NULL_TREE, DECL_GC_OFFSET (to)); | |
314 | cleanup = build_function_call (gc_unprotect_fndecl, | |
315 | DECL_GC_OFFSET (to)); | |
316 | ||
317 | if (! expand_decl_cleanup (to, cleanup)) | |
318 | { | |
319 | compiler_error ("cannot unprotect parameter in this scope"); | |
320 | return error_mark_node; | |
321 | } | |
322 | } | |
323 | ||
324 | /* Should never need to protect a value that's headed for static storage. */ | |
325 | if (TREE_STATIC (to)) | |
326 | my_friendly_abort (44); | |
327 | ||
328 | switch (TREE_CODE (to)) | |
329 | { | |
330 | case COMPONENT_REF: | |
331 | case INDIRECT_REF: | |
332 | return protect_value_from_gc (TREE_OPERAND (to, 0), from); | |
333 | ||
334 | case VAR_DECL: | |
335 | case PARM_DECL: | |
336 | { | |
337 | tree rval; | |
338 | if (DECL_GC_OFFSET (to) == NULL_TREE) | |
339 | { | |
340 | /* Because of a cast or a conversion, we might stick | |
341 | a value into a variable that would not normally | |
342 | have a GC entry. */ | |
343 | DECL_GC_OFFSET (to) = size_int (++current_function_obstack_index); | |
344 | } | |
345 | ||
346 | if (TREE_CODE (DECL_GC_OFFSET (to)) != TREE_LIST) | |
347 | { | |
348 | DECL_GC_OFFSET (to) | |
349 | = build_tree_list (NULL_TREE, DECL_GC_OFFSET (to)); | |
350 | } | |
351 | ||
352 | current_function_obstack_usage = 1; | |
353 | rval = build_function_call (gc_protect_fndecl, | |
354 | tree_cons (NULL_TREE, from, | |
355 | DECL_GC_OFFSET (to))); | |
356 | TREE_TYPE (rval) = TREE_TYPE (from); | |
357 | return rval; | |
358 | } | |
359 | } | |
360 | ||
361 | /* If we fall through the switch, assume we lost. */ | |
362 | my_friendly_abort (45); | |
363 | /* NOTREACHED */ | |
364 | return NULL_TREE; | |
365 | } | |
366 | \f | |
367 | /* Given the expression EXP of type `class *', return the head | |
368 | of the object pointed to by EXP. */ | |
369 | tree | |
370 | build_headof (exp) | |
371 | tree exp; | |
372 | { | |
373 | tree type = TREE_TYPE (exp); | |
374 | tree vptr, offset; | |
375 | ||
376 | if (TREE_CODE (type) != POINTER_TYPE) | |
377 | { | |
378 | error ("`headof' applied to non-pointer type"); | |
379 | return error_mark_node; | |
380 | } | |
381 | ||
382 | vptr = build1 (INDIRECT_REF, TYPE_POINTER_TO (vtable_entry_type), exp); | |
383 | offset = build_component_ref (build_array_ref (vptr, integer_one_node), | |
384 | get_identifier (VTABLE_DELTA_NAME), | |
385 | NULL_TREE, 0); | |
386 | return build (PLUS_EXPR, class_star_type_node, exp, | |
387 | convert (integer_type_node, offset)); | |
388 | } | |
389 | ||
390 | /* Given the expression EXP of type `class *', return the | |
391 | type descriptor for the object pointed to by EXP. */ | |
392 | tree | |
393 | build_classof (exp) | |
394 | tree exp; | |
395 | { | |
396 | tree type = TREE_TYPE (exp); | |
397 | tree vptr; | |
398 | tree t_desc_entry; | |
399 | ||
400 | if (TREE_CODE (type) != POINTER_TYPE) | |
401 | { | |
402 | error ("`classof' applied to non-pointer type"); | |
403 | return error_mark_node; | |
404 | } | |
405 | ||
406 | vptr = build1 (INDIRECT_REF, TYPE_POINTER_TO (vtable_entry_type), exp); | |
407 | t_desc_entry = build_component_ref (build_array_ref (vptr, integer_one_node), | |
408 | get_identifier (VTABLE_PFN_NAME), | |
409 | NULL_TREE, 0); | |
410 | TREE_TYPE (t_desc_entry) = TYPE_POINTER_TO (__t_desc_type_node); | |
411 | return t_desc_entry; | |
412 | } | |
413 | \f | |
414 | /* Build and initialize various sorts of descriptors. Every descriptor | |
415 | node has a name associated with it (the name created by mangling). | |
416 | For this reason, we use the identifier as our access to the __*_desc | |
417 | nodes, instead of sticking them directly in the types. Otherwise we | |
418 | would burden all built-in types (and pointer types) with slots that | |
419 | we don't necessarily want to use. | |
420 | ||
421 | For each descriptor we build, we build a variable that contains | |
422 | the descriptor's information. When we need this info at runtime, | |
423 | all we need is access to these variables. | |
424 | ||
425 | Note: these constructors always return the address of the descriptor | |
426 | info, since that is simplest for their mutual interaction. */ | |
427 | ||
428 | static tree | |
429 | build_generic_desc (decl, elems) | |
430 | tree decl; | |
431 | tree elems; | |
432 | { | |
433 | tree init = build (CONSTRUCTOR, TREE_TYPE (decl), NULL_TREE, elems); | |
434 | TREE_CONSTANT (init) = 1; | |
435 | TREE_STATIC (init) = 1; | |
436 | TREE_READONLY (init) = 1; | |
437 | ||
438 | DECL_INITIAL (decl) = init; | |
439 | TREE_STATIC (decl) = 1; | |
440 | layout_decl (decl, 0); | |
441 | finish_decl (decl, init, 0, 0); | |
442 | ||
443 | return IDENTIFIER_AS_DESC (DECL_NAME (decl)); | |
444 | } | |
445 | ||
446 | /* Build an initializer for a __t_desc node. So that we can take advantage | |
447 | of recursion, we accept NULL for TYPE. | |
448 | DEFINITION is greater than zero iff we must define the type descriptor | |
449 | (as opposed to merely referencing it). 1 means treat according to | |
450 | #pragma interface/#pragma implementation rules. 2 means define as | |
451 | global and public, no matter what. */ | |
452 | tree | |
453 | build_t_desc (type, definition) | |
454 | tree type; | |
455 | int definition; | |
456 | { | |
457 | tree tdecl; | |
458 | tree tname, name_string; | |
459 | tree elems, fields; | |
460 | tree parents, vbases, offsets, ivars, methods, target_type; | |
461 | int method_count = 0, field_count = 0; | |
462 | ||
463 | if (type == NULL_TREE) | |
464 | return NULL_TREE; | |
465 | ||
466 | tname = build_t_desc_overload (type); | |
467 | if (IDENTIFIER_AS_DESC (tname) | |
468 | && (!definition || TREE_ASM_WRITTEN (IDENTIFIER_AS_DESC (tname)))) | |
469 | return IDENTIFIER_AS_DESC (tname); | |
470 | ||
471 | tdecl = lookup_name (tname, 0); | |
472 | if (tdecl == NULL_TREE) | |
473 | { | |
474 | tdecl = build_decl (VAR_DECL, tname, __t_desc_type_node); | |
475 | DECL_EXTERNAL (tdecl) = 1; | |
476 | TREE_PUBLIC (tdecl) = 1; | |
477 | tdecl = pushdecl_top_level (tdecl); | |
478 | } | |
479 | /* If we previously defined it, return the defined result. */ | |
480 | else if (definition && DECL_INITIAL (tdecl)) | |
481 | return IDENTIFIER_AS_DESC (tname); | |
482 | ||
483 | if (definition) | |
484 | { | |
485 | tree taggr = type; | |
486 | /* Let T* and T& be written only when T is written (if T is an aggr). | |
487 | We do this for const, but not for volatile, since volatile | |
488 | is rare and const is not. */ | |
489 | if (!TYPE_VOLATILE (taggr) | |
490 | && (TREE_CODE (taggr) == POINTER_TYPE | |
491 | || TREE_CODE (taggr) == REFERENCE_TYPE) | |
492 | && IS_AGGR_TYPE (TREE_TYPE (taggr))) | |
493 | taggr = TREE_TYPE (taggr); | |
494 | ||
495 | /* If we know that we don't need to write out this type's | |
496 | vtable, then don't write out it's dossier. Somebody | |
497 | else will take care of that. */ | |
498 | if (IS_AGGR_TYPE (taggr) && CLASSTYPE_VFIELD (taggr)) | |
499 | { | |
500 | if (CLASSTYPE_VTABLE_NEEDS_WRITING (taggr)) | |
501 | { | |
502 | TREE_PUBLIC (tdecl) = !(CLASSTYPE_INTERFACE_ONLY (taggr) | |
503 | || CLASSTYPE_INTERFACE_UNKNOWN (taggr)); | |
504 | TREE_STATIC (tdecl) = 1; | |
505 | DECL_EXTERNAL (tdecl) = 0; | |
506 | } | |
507 | else | |
508 | { | |
509 | if (write_virtuals != 0) | |
510 | TREE_PUBLIC (tdecl) = 1; | |
511 | } | |
512 | } | |
513 | else | |
514 | { | |
515 | DECL_EXTERNAL (tdecl) = 0; | |
516 | TREE_STATIC (tdecl) = 1; | |
517 | TREE_PUBLIC (tdecl) = (definition > 1); | |
518 | } | |
519 | } | |
520 | SET_IDENTIFIER_AS_DESC (tname, build_unary_op (ADDR_EXPR, tdecl, 0)); | |
521 | if (!definition || DECL_EXTERNAL (tdecl)) | |
522 | { | |
523 | /* That's it! */ | |
524 | finish_decl (tdecl, 0, 0, 0); | |
525 | return IDENTIFIER_AS_DESC (tname); | |
526 | } | |
527 | ||
528 | /* Show that we are defining the t_desc for this type. */ | |
529 | DECL_INITIAL (tdecl) = error_mark_node; | |
530 | ||
531 | parents = build_tree_list (NULL_TREE, integer_zero_node); | |
532 | vbases = build_tree_list (NULL_TREE, integer_zero_node); | |
533 | offsets = build_tree_list (NULL_TREE, integer_zero_node); | |
534 | methods = NULL_TREE; | |
535 | ivars = NULL_TREE; | |
536 | ||
537 | if (TYPE_LANG_SPECIFIC (type)) | |
538 | { | |
539 | int i = CLASSTYPE_N_BASECLASSES (type); | |
540 | tree method_vec = CLASSTYPE_METHOD_VEC (type); | |
541 | tree *meth, *end; | |
542 | tree binfos = TYPE_BINFO_BASETYPES (type); | |
543 | tree vb = CLASSTYPE_VBASECLASSES (type); | |
544 | ||
545 | while (--i >= 0) | |
546 | parents = tree_cons (NULL_TREE, build_t_desc (BINFO_TYPE (TREE_VEC_ELT (binfos, i)), 0), parents); | |
547 | ||
548 | while (vb) | |
549 | { | |
550 | vbases = tree_cons (NULL_TREE, build_t_desc (BINFO_TYPE (vb), 0), vbases); | |
551 | offsets = tree_cons (NULL_TREE, BINFO_OFFSET (vb), offsets); | |
552 | vb = TREE_CHAIN (vb); | |
553 | } | |
554 | ||
555 | if (method_vec) | |
556 | for (meth = TREE_VEC_END (method_vec), | |
557 | end = &TREE_VEC_ELT (method_vec, 0); meth-- != end; ) | |
558 | if (*meth) | |
559 | { | |
560 | methods = tree_cons (NULL_TREE, build_m_desc (*meth), methods); | |
561 | method_count++; | |
562 | } | |
563 | } | |
564 | ||
565 | if (IS_AGGR_TYPE (type)) | |
566 | { | |
567 | for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) | |
568 | if (TREE_CODE (fields) == FIELD_DECL | |
569 | || TREE_CODE (fields) == VAR_DECL) | |
570 | { | |
571 | ivars = tree_cons (NULL_TREE, build_i_desc (fields), ivars); | |
572 | field_count++; | |
573 | } | |
574 | ivars = nreverse (ivars); | |
575 | } | |
576 | ||
577 | parents = finish_table (0, TYPE_POINTER_TO (__t_desc_type_node), parents, 0); | |
578 | vbases = finish_table (0, TYPE_POINTER_TO (__t_desc_type_node), vbases, 0); | |
579 | offsets = finish_table (0, integer_type_node, offsets, 0); | |
580 | methods = finish_table (0, __m_desc_type_node, methods, 0); | |
581 | ivars = finish_table (0, __i_desc_type_node, ivars, 0); | |
582 | if (TREE_TYPE (type)) | |
583 | target_type = build_t_desc (TREE_TYPE (type), definition); | |
584 | else | |
585 | target_type = integer_zero_node; | |
586 | ||
587 | name_string = combine_strings (build_string (IDENTIFIER_LENGTH (tname)+1, IDENTIFIER_POINTER (tname))); | |
588 | ||
589 | elems = tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, name_string, 0), | |
590 | tree_cons (NULL_TREE, | |
591 | TYPE_SIZE(type)? size_in_bytes(type) : integer_zero_node, | |
592 | /* really should use bitfield initialization here. */ | |
593 | tree_cons (NULL_TREE, integer_zero_node, | |
594 | tree_cons (NULL_TREE, target_type, | |
595 | tree_cons (NULL_TREE, build_int_2 (field_count, 2), | |
596 | tree_cons (NULL_TREE, build_int_2 (method_count, 2), | |
597 | tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, ivars, 0), | |
598 | tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, methods, 0), | |
599 | tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, parents, 0), | |
600 | tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, vbases, 0), | |
601 | build_tree_list (NULL_TREE, build_unary_op (ADDR_EXPR, offsets, 0)))))))))))); | |
602 | return build_generic_desc (tdecl, elems); | |
603 | } | |
604 | ||
605 | /* Build an initializer for a __i_desc node. */ | |
606 | tree | |
607 | build_i_desc (decl) | |
608 | tree decl; | |
609 | { | |
610 | tree elems, name_string; | |
611 | tree taggr; | |
612 | ||
613 | name_string = DECL_NAME (decl); | |
614 | name_string = combine_strings (build_string (IDENTIFIER_LENGTH (name_string)+1, IDENTIFIER_POINTER (name_string))); | |
615 | ||
616 | /* Now decide whether this ivar should cause it's type to get | |
617 | def'd or ref'd in this file. If the type we are looking at | |
618 | has a proxy definition, we look at the proxy (i.e., a | |
619 | `foo *' is equivalent to a `foo'). */ | |
620 | taggr = TREE_TYPE (decl); | |
621 | ||
622 | if ((TREE_CODE (taggr) == POINTER_TYPE | |
623 | || TREE_CODE (taggr) == REFERENCE_TYPE) | |
624 | && TYPE_VOLATILE (taggr) == 0) | |
625 | taggr = TREE_TYPE (taggr); | |
626 | ||
627 | elems = tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, name_string, 0), | |
628 | tree_cons (NULL_TREE, DECL_FIELD_BITPOS (decl), | |
629 | build_tree_list (NULL_TREE, build_t_desc (TREE_TYPE (decl), | |
630 | ! IS_AGGR_TYPE (taggr))))); | |
631 | taggr = build (CONSTRUCTOR, __i_desc_type_node, NULL_TREE, elems); | |
632 | TREE_CONSTANT (taggr) = 1; | |
633 | TREE_STATIC (taggr) = 1; | |
634 | TREE_READONLY (taggr) = 1; | |
635 | return taggr; | |
636 | } | |
637 | ||
638 | /* Build an initializer for a __m_desc node. */ | |
639 | tree | |
640 | build_m_desc (decl) | |
641 | tree decl; | |
642 | { | |
643 | tree taggr, elems, name_string; | |
644 | tree parm_count, req_count, vindex, vcontext; | |
645 | tree parms; | |
646 | int p_count, r_count; | |
647 | tree parm_types = NULL_TREE; | |
648 | ||
649 | for (parms = TYPE_ARG_TYPES (TREE_TYPE (decl)), p_count = 0, r_count = 0; | |
650 | parms != NULL_TREE; parms = TREE_CHAIN (parms), p_count++) | |
651 | { | |
652 | taggr = TREE_VALUE (parms); | |
653 | if ((TREE_CODE (taggr) == POINTER_TYPE | |
654 | || TREE_CODE (taggr) == REFERENCE_TYPE) | |
655 | && TYPE_VOLATILE (taggr) == 0) | |
656 | taggr = TREE_TYPE (taggr); | |
657 | ||
658 | parm_types = tree_cons (NULL_TREE, build_t_desc (TREE_VALUE (parms), | |
659 | ! IS_AGGR_TYPE (taggr)), | |
660 | parm_types); | |
661 | if (TREE_PURPOSE (parms) == NULL_TREE) | |
662 | r_count++; | |
663 | } | |
664 | ||
665 | parm_types = finish_table (0, TYPE_POINTER_TO (__t_desc_type_node), | |
666 | nreverse (parm_types), 0); | |
667 | parm_count = build_int_2 (p_count, 0); | |
668 | req_count = build_int_2 (r_count, 0); | |
669 | ||
670 | if (DECL_VINDEX (decl)) | |
671 | vindex = DECL_VINDEX (decl); | |
672 | else | |
673 | vindex = integer_zero_node; | |
674 | if (DECL_CONTEXT (decl) | |
675 | && TREE_CODE_CLASS (TREE_CODE (DECL_CONTEXT (decl))) == 't') | |
676 | vcontext = build_t_desc (DECL_CONTEXT (decl), 0); | |
677 | else | |
678 | vcontext = integer_zero_node; | |
679 | name_string = DECL_NAME (decl); | |
680 | if (name_string == NULL) | |
681 | name_string = DECL_ASSEMBLER_NAME (decl); | |
682 | name_string = combine_strings (build_string (IDENTIFIER_LENGTH (name_string)+1, IDENTIFIER_POINTER (name_string))); | |
683 | ||
684 | /* Now decide whether the return type of this mvar | |
685 | should cause it's type to get def'd or ref'd in this file. | |
686 | If the type we are looking at has a proxy definition, | |
687 | we look at the proxy (i.e., a `foo *' is equivalent to a `foo'). */ | |
688 | taggr = TREE_TYPE (TREE_TYPE (decl)); | |
689 | ||
690 | if ((TREE_CODE (taggr) == POINTER_TYPE | |
691 | || TREE_CODE (taggr) == REFERENCE_TYPE) | |
692 | && TYPE_VOLATILE (taggr) == 0) | |
693 | taggr = TREE_TYPE (taggr); | |
694 | ||
695 | elems = tree_cons (NULL_TREE, build_unary_op (ADDR_EXPR, name_string, 0), | |
696 | tree_cons (NULL_TREE, vindex, | |
697 | tree_cons (NULL_TREE, vcontext, | |
698 | tree_cons (NULL_TREE, build_t_desc (TREE_TYPE (TREE_TYPE (decl)), | |
699 | ! IS_AGGR_TYPE (taggr)), | |
700 | tree_cons (NULL_TREE, build_c_cast (TYPE_POINTER_TO (default_function_type), build_unary_op (ADDR_EXPR, decl, 0)), | |
701 | tree_cons (NULL_TREE, parm_count, | |
702 | tree_cons (NULL_TREE, req_count, | |
703 | build_tree_list (NULL_TREE, build_unary_op (ADDR_EXPR, parm_types, 0))))))))); | |
704 | ||
705 | taggr = build (CONSTRUCTOR, __m_desc_type_node, NULL_TREE, elems); | |
706 | TREE_CONSTANT (taggr) = 1; | |
707 | TREE_STATIC (taggr) = 1; | |
708 | TREE_READONLY (taggr) = 1; | |
709 | return taggr; | |
710 | } | |
711 | \f | |
712 | /* Conditionally emit code to set up an unwind-protect for the | |
713 | garbage collector. If this function doesn't do anything that involves | |
714 | the garbage collector, then do nothing. Otherwise, call __gc_push | |
715 | at the beginning and __gc_pop at the end. | |
716 | ||
717 | NOTE! The __gc_pop function must operate transparently, since | |
718 | it comes where the logical return label lies. This means that | |
719 | at runtime *it* must preserve any return value registers. */ | |
720 | ||
721 | void | |
722 | expand_gc_prologue_and_epilogue () | |
723 | { | |
724 | extern tree maybe_gc_cleanup; | |
725 | struct rtx_def *last_parm_insn, *mark; | |
726 | extern struct rtx_def *get_last_insn (); | |
727 | extern struct rtx_def *get_first_nonparm_insn (); | |
728 | extern struct rtx_def *previous_insn (); | |
729 | tree action; | |
730 | ||
731 | /* If we didn't need the obstack, don't cons any space. */ | |
732 | if (current_function_obstack_index == 0 | |
733 | || current_function_obstack_usage == 0) | |
734 | return; | |
735 | ||
736 | mark = get_last_insn (); | |
737 | last_parm_insn = get_first_nonparm_insn (); | |
738 | if (last_parm_insn == 0) last_parm_insn = mark; | |
739 | else last_parm_insn = previous_insn (last_parm_insn); | |
740 | ||
741 | action = build_function_call (gc_push_fndecl, | |
742 | build_tree_list (NULL_TREE, size_int (++current_function_obstack_index))); | |
743 | expand_expr_stmt (action); | |
744 | ||
745 | reorder_insns (next_insn (mark), get_last_insn (), last_parm_insn); | |
746 | ||
747 | /* This will be expanded as a cleanup. */ | |
748 | TREE_VALUE (maybe_gc_cleanup) | |
749 | = build_function_call (gc_pop_fndecl, NULL_TREE); | |
750 | } | |
751 | ||
752 | /* Some day we'll use this function as a call-back and clean | |
753 | up all the unnecessary gc dribble that we otherwise create. */ | |
754 | void | |
755 | lang_expand_end_bindings (first, last) | |
756 | struct rtx_def *first, *last; | |
757 | { | |
758 | } | |
759 | \f | |
760 | void | |
761 | init_gc_processing () | |
762 | { | |
763 | tree parmtypes = hash_tree_chain (class_star_type_node, | |
764 | hash_tree_chain (integer_type_node, NULL_TREE)); | |
765 | gc_protect_fndecl = define_function ("__gc_protect", | |
766 | build_function_type (class_star_type_node, parmtypes), | |
767 | NOT_BUILT_IN, 0, 0); | |
768 | ||
769 | parmtypes = hash_tree_chain (integer_type_node, NULL_TREE); | |
770 | gc_unprotect_fndecl = define_function ("__gc_unprotect", | |
771 | build_function_type (void_type_node, parmtypes), | |
772 | NOT_BUILT_IN, 0, 0); | |
773 | ||
774 | gc_push_fndecl = define_function ("__gc_push", | |
775 | TREE_TYPE (gc_unprotect_fndecl), | |
776 | NOT_BUILT_IN, 0, 0); | |
777 | ||
778 | gc_pop_fndecl = define_function ("__gc_pop", | |
779 | build_function_type (void_type_node, | |
780 | void_list_node), | |
781 | NOT_BUILT_IN, 0, 0); | |
782 | gc_nonobject = build_int_2 (0x80000000, 0); | |
783 | gc_visible = build_int_2 (0x40000000, 0); | |
784 | gc_white = integer_zero_node; | |
785 | gc_offwhite = build_int_2 (0x10000000, 0); | |
786 | gc_grey = build_int_2 (0x20000000, 0); | |
787 | gc_black = build_int_2 (0x30000000, 0); | |
788 | } |