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8d326f11 | 1 | /* Analysis of polymorphic call context. |
8e8f6434 | 2 | Copyright (C) 2013-2018 Free Software Foundation, Inc. |
8d326f11 | 3 | Contributed by Jan Hubicka |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 3, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
9ef16211 | 24 | #include "backend.h" |
7c29e30e | 25 | #include "rtl.h" |
8d326f11 | 26 | #include "tree.h" |
9ef16211 | 27 | #include "gimple.h" |
7c29e30e | 28 | #include "tree-pass.h" |
29 | #include "tree-ssa-operands.h" | |
7c29e30e | 30 | #include "streamer-hooks.h" |
31 | #include "cgraph.h" | |
32 | #include "data-streamer.h" | |
33 | #include "diagnostic.h" | |
9ef16211 | 34 | #include "alias.h" |
b20a8bb4 | 35 | #include "fold-const.h" |
8d326f11 | 36 | #include "calls.h" |
8d326f11 | 37 | #include "ipa-utils.h" |
8d326f11 | 38 | #include "tree-dfa.h" |
8d326f11 | 39 | #include "gimple-pretty-print.h" |
9327cf31 | 40 | #include "tree-into-ssa.h" |
1140bac5 | 41 | #include "params.h" |
8d326f11 | 42 | |
43 | /* Return true when TYPE contains an polymorphic type and thus is interesting | |
44 | for devirtualization machinery. */ | |
45 | ||
2b7b45ca | 46 | static bool contains_type_p (tree, HOST_WIDE_INT, tree, |
47 | bool consider_placement_new = true, | |
48 | bool consider_bases = true); | |
8d326f11 | 49 | |
50 | bool | |
51 | contains_polymorphic_type_p (const_tree type) | |
52 | { | |
53 | type = TYPE_MAIN_VARIANT (type); | |
54 | ||
55 | if (RECORD_OR_UNION_TYPE_P (type)) | |
56 | { | |
57 | if (TYPE_BINFO (type) | |
58 | && polymorphic_type_binfo_p (TYPE_BINFO (type))) | |
59 | return true; | |
60 | for (tree fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) | |
61 | if (TREE_CODE (fld) == FIELD_DECL | |
62 | && !DECL_ARTIFICIAL (fld) | |
63 | && contains_polymorphic_type_p (TREE_TYPE (fld))) | |
64 | return true; | |
65 | return false; | |
66 | } | |
67 | if (TREE_CODE (type) == ARRAY_TYPE) | |
68 | return contains_polymorphic_type_p (TREE_TYPE (type)); | |
69 | return false; | |
70 | } | |
71 | ||
72 | /* Return true if it seems valid to use placement new to build EXPECTED_TYPE | |
73 | at possition CUR_OFFSET within TYPE. | |
74 | ||
75 | POD can be changed to an instance of a polymorphic type by | |
76 | placement new. Here we play safe and assume that any | |
77 | non-polymorphic type is POD. */ | |
78 | bool | |
79 | possible_placement_new (tree type, tree expected_type, | |
80 | HOST_WIDE_INT cur_offset) | |
81 | { | |
edbc08a8 | 82 | if (cur_offset < 0) |
83 | return true; | |
8d326f11 | 84 | return ((TREE_CODE (type) != RECORD_TYPE |
85 | || !TYPE_BINFO (type) | |
139e42e6 | 86 | || cur_offset >= POINTER_SIZE |
8d326f11 | 87 | || !polymorphic_type_binfo_p (TYPE_BINFO (type))) |
88 | && (!TYPE_SIZE (type) | |
89 | || !tree_fits_shwi_p (TYPE_SIZE (type)) | |
90 | || (cur_offset | |
91 | + (expected_type ? tree_to_uhwi (TYPE_SIZE (expected_type)) | |
c5dfddcf | 92 | : POINTER_SIZE) |
8d326f11 | 93 | <= tree_to_uhwi (TYPE_SIZE (type))))); |
94 | } | |
95 | ||
2b7b45ca | 96 | /* THIS->OUTER_TYPE is a type of memory object where object of OTR_TYPE |
8d326f11 | 97 | is contained at THIS->OFFSET. Walk the memory representation of |
98 | THIS->OUTER_TYPE and find the outermost class type that match | |
2b7b45ca | 99 | OTR_TYPE or contain OTR_TYPE as a base. Update THIS |
8d326f11 | 100 | to represent it. |
101 | ||
2b7b45ca | 102 | If OTR_TYPE is NULL, just find outermost polymorphic type with |
8d326f11 | 103 | virtual table present at possition OFFSET. |
104 | ||
105 | For example when THIS represents type | |
106 | class A | |
107 | { | |
108 | int a; | |
109 | class B b; | |
110 | } | |
111 | and we look for type at offset sizeof(int), we end up with B and offset 0. | |
112 | If the same is produced by multiple inheritance, we end up with A and offset | |
113 | sizeof(int). | |
114 | ||
115 | If we can not find corresponding class, give up by setting | |
2b7b45ca | 116 | THIS->OUTER_TYPE to OTR_TYPE and THIS->OFFSET to NULL. |
117 | Return true when lookup was sucesful. | |
118 | ||
119 | When CONSIDER_PLACEMENT_NEW is false, reject contexts that may be made | |
2fbe7a32 | 120 | valid only via allocation of new polymorphic type inside by means |
2b7b45ca | 121 | of placement new. |
122 | ||
123 | When CONSIDER_BASES is false, only look for actual fields, not base types | |
124 | of TYPE. */ | |
8d326f11 | 125 | |
126 | bool | |
2b7b45ca | 127 | ipa_polymorphic_call_context::restrict_to_inner_class (tree otr_type, |
128 | bool consider_placement_new, | |
129 | bool consider_bases) | |
8d326f11 | 130 | { |
131 | tree type = outer_type; | |
132 | HOST_WIDE_INT cur_offset = offset; | |
133 | bool speculative = false; | |
134 | bool size_unknown = false; | |
c5dfddcf | 135 | unsigned HOST_WIDE_INT otr_type_size = POINTER_SIZE; |
8d326f11 | 136 | |
137 | /* Update OUTER_TYPE to match EXPECTED_TYPE if it is not set. */ | |
138 | if (!outer_type) | |
139 | { | |
2b7b45ca | 140 | clear_outer_type (otr_type); |
141 | type = otr_type; | |
8d326f11 | 142 | cur_offset = 0; |
143 | } | |
144 | /* See if OFFSET points inside OUTER_TYPE. If it does not, we know | |
145 | that the context is either invalid, or the instance type must be | |
146 | derived from OUTER_TYPE. | |
147 | ||
148 | Because the instance type may contain field whose type is of OUTER_TYPE, | |
149 | we can not derive any effective information about it. | |
150 | ||
151 | TODO: In the case we know all derrived types, we can definitely do better | |
152 | here. */ | |
153 | else if (TYPE_SIZE (outer_type) | |
154 | && tree_fits_shwi_p (TYPE_SIZE (outer_type)) | |
155 | && tree_to_shwi (TYPE_SIZE (outer_type)) >= 0 | |
156 | && tree_to_shwi (TYPE_SIZE (outer_type)) <= offset) | |
157 | { | |
00a8cb04 | 158 | bool der = maybe_derived_type; /* clear_outer_type will reset it. */ |
159 | bool dyn = dynamic; | |
2b7b45ca | 160 | clear_outer_type (otr_type); |
161 | type = otr_type; | |
8d326f11 | 162 | cur_offset = 0; |
163 | ||
c500eb01 | 164 | /* If derived type is not allowed, we know that the context is invalid. |
165 | For dynamic types, we really do not have information about | |
166 | size of the memory location. It is possible that completely | |
167 | different type is stored after outer_type. */ | |
00a8cb04 | 168 | if (!der && !dyn) |
8d326f11 | 169 | { |
170 | clear_speculation (); | |
171 | invalid = true; | |
172 | return false; | |
173 | } | |
174 | } | |
175 | ||
2b7b45ca | 176 | if (otr_type && TYPE_SIZE (otr_type) |
177 | && tree_fits_shwi_p (TYPE_SIZE (otr_type))) | |
178 | otr_type_size = tree_to_uhwi (TYPE_SIZE (otr_type)); | |
8d326f11 | 179 | |
2b7b45ca | 180 | if (!type || offset < 0) |
8d326f11 | 181 | goto no_useful_type_info; |
182 | ||
183 | /* Find the sub-object the constant actually refers to and mark whether it is | |
184 | an artificial one (as opposed to a user-defined one). | |
185 | ||
186 | This loop is performed twice; first time for outer_type and second time | |
187 | for speculative_outer_type. The second run has SPECULATIVE set. */ | |
188 | while (true) | |
189 | { | |
2b7b45ca | 190 | unsigned HOST_WIDE_INT pos, size; |
8d326f11 | 191 | tree fld; |
192 | ||
193 | /* If we do not know size of TYPE, we need to be more conservative | |
194 | about accepting cases where we can not find EXPECTED_TYPE. | |
195 | Generally the types that do matter here are of constant size. | |
196 | Size_unknown case should be very rare. */ | |
197 | if (TYPE_SIZE (type) | |
198 | && tree_fits_shwi_p (TYPE_SIZE (type)) | |
199 | && tree_to_shwi (TYPE_SIZE (type)) >= 0) | |
200 | size_unknown = false; | |
201 | else | |
202 | size_unknown = true; | |
203 | ||
204 | /* On a match, just return what we found. */ | |
2b7b45ca | 205 | if ((otr_type |
206 | && types_odr_comparable (type, otr_type) | |
207 | && types_same_for_odr (type, otr_type)) | |
208 | || (!otr_type | |
8d326f11 | 209 | && TREE_CODE (type) == RECORD_TYPE |
210 | && TYPE_BINFO (type) | |
211 | && polymorphic_type_binfo_p (TYPE_BINFO (type)))) | |
212 | { | |
213 | if (speculative) | |
214 | { | |
215 | /* If we did not match the offset, just give up on speculation. */ | |
216 | if (cur_offset != 0 | |
217 | /* Also check if speculation did not end up being same as | |
218 | non-speculation. */ | |
219 | || (types_must_be_same_for_odr (speculative_outer_type, | |
220 | outer_type) | |
221 | && (maybe_derived_type | |
222 | == speculative_maybe_derived_type))) | |
223 | clear_speculation (); | |
224 | return true; | |
225 | } | |
226 | else | |
227 | { | |
228 | /* If type is known to be final, do not worry about derived | |
229 | types. Testing it here may help us to avoid speculation. */ | |
2b7b45ca | 230 | if (otr_type && TREE_CODE (outer_type) == RECORD_TYPE |
231 | && (!in_lto_p || odr_type_p (outer_type)) | |
2bfdc8e7 | 232 | && type_with_linkage_p (outer_type) |
233 | && type_known_to_have_no_derivations_p (outer_type)) | |
8d326f11 | 234 | maybe_derived_type = false; |
235 | ||
236 | /* Type can not contain itself on an non-zero offset. In that case | |
237 | just give up. Still accept the case where size is now known. | |
238 | Either the second copy may appear past the end of type or within | |
239 | the non-POD buffer located inside the variably sized type | |
240 | itself. */ | |
241 | if (cur_offset != 0) | |
242 | goto no_useful_type_info; | |
243 | /* If we determined type precisely or we have no clue on | |
244 | speuclation, we are done. */ | |
2b7b45ca | 245 | if (!maybe_derived_type || !speculative_outer_type |
246 | || !speculation_consistent_p (speculative_outer_type, | |
247 | speculative_offset, | |
248 | speculative_maybe_derived_type, | |
249 | otr_type)) | |
8d326f11 | 250 | { |
251 | clear_speculation (); | |
252 | return true; | |
253 | } | |
254 | /* Otherwise look into speculation now. */ | |
255 | else | |
256 | { | |
257 | speculative = true; | |
258 | type = speculative_outer_type; | |
259 | cur_offset = speculative_offset; | |
260 | continue; | |
261 | } | |
262 | } | |
263 | } | |
264 | ||
265 | /* Walk fields and find corresponding on at OFFSET. */ | |
266 | if (TREE_CODE (type) == RECORD_TYPE) | |
267 | { | |
268 | for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) | |
269 | { | |
b13f363a | 270 | if (TREE_CODE (fld) != FIELD_DECL |
271 | || TREE_TYPE (fld) == error_mark_node) | |
8d326f11 | 272 | continue; |
273 | ||
274 | pos = int_bit_position (fld); | |
2b7b45ca | 275 | if (pos > (unsigned HOST_WIDE_INT)cur_offset) |
276 | continue; | |
1986ca43 | 277 | |
278 | /* Do not consider vptr itself. Not even for placement new. */ | |
279 | if (!pos && DECL_ARTIFICIAL (fld) | |
280 | && POINTER_TYPE_P (TREE_TYPE (fld)) | |
281 | && TYPE_BINFO (type) | |
282 | && polymorphic_type_binfo_p (TYPE_BINFO (type))) | |
283 | continue; | |
284 | ||
2b7b45ca | 285 | if (!DECL_SIZE (fld) || !tree_fits_uhwi_p (DECL_SIZE (fld))) |
286 | goto no_useful_type_info; | |
8d326f11 | 287 | size = tree_to_uhwi (DECL_SIZE (fld)); |
2b7b45ca | 288 | |
289 | /* We can always skip types smaller than pointer size: | |
290 | those can not contain a virtual table pointer. | |
291 | ||
292 | Disqualifying fields that are too small to fit OTR_TYPE | |
293 | saves work needed to walk them for no benefit. | |
294 | Because of the way the bases are packed into a class, the | |
295 | field's size may be smaller than type size, so it needs | |
296 | to be done with a care. */ | |
297 | ||
298 | if (pos <= (unsigned HOST_WIDE_INT)cur_offset | |
299 | && (pos + size) >= (unsigned HOST_WIDE_INT)cur_offset | |
c5dfddcf | 300 | + POINTER_SIZE |
2b7b45ca | 301 | && (!otr_type |
302 | || !TYPE_SIZE (TREE_TYPE (fld)) | |
303 | || !tree_fits_shwi_p (TYPE_SIZE (TREE_TYPE (fld))) | |
304 | || (pos + tree_to_uhwi (TYPE_SIZE (TREE_TYPE (fld)))) | |
305 | >= cur_offset + otr_type_size)) | |
8d326f11 | 306 | break; |
307 | } | |
308 | ||
309 | if (!fld) | |
310 | goto no_useful_type_info; | |
311 | ||
312 | type = TYPE_MAIN_VARIANT (TREE_TYPE (fld)); | |
313 | cur_offset -= pos; | |
314 | /* DECL_ARTIFICIAL represents a basetype. */ | |
315 | if (!DECL_ARTIFICIAL (fld)) | |
316 | { | |
317 | if (!speculative) | |
318 | { | |
319 | outer_type = type; | |
320 | offset = cur_offset; | |
321 | /* As soon as we se an field containing the type, | |
322 | we know we are not looking for derivations. */ | |
323 | maybe_derived_type = false; | |
324 | } | |
325 | else | |
326 | { | |
327 | speculative_outer_type = type; | |
328 | speculative_offset = cur_offset; | |
329 | speculative_maybe_derived_type = false; | |
330 | } | |
331 | } | |
2b7b45ca | 332 | else if (!consider_bases) |
333 | goto no_useful_type_info; | |
8d326f11 | 334 | } |
335 | else if (TREE_CODE (type) == ARRAY_TYPE) | |
336 | { | |
337 | tree subtype = TYPE_MAIN_VARIANT (TREE_TYPE (type)); | |
338 | ||
2b7b45ca | 339 | /* Give up if we don't know array field size. |
340 | Also give up on non-polymorphic types as they are used | |
341 | as buffers for placement new. */ | |
8d326f11 | 342 | if (!TYPE_SIZE (subtype) |
343 | || !tree_fits_shwi_p (TYPE_SIZE (subtype)) | |
344 | || tree_to_shwi (TYPE_SIZE (subtype)) <= 0 | |
345 | || !contains_polymorphic_type_p (subtype)) | |
346 | goto no_useful_type_info; | |
347 | ||
348 | HOST_WIDE_INT new_offset = cur_offset % tree_to_shwi (TYPE_SIZE (subtype)); | |
349 | ||
350 | /* We may see buffer for placement new. In this case the expected type | |
351 | can be bigger than the subtype. */ | |
352 | if (TYPE_SIZE (subtype) | |
2b7b45ca | 353 | && (cur_offset + otr_type_size |
5100acd2 | 354 | > tree_to_uhwi (TYPE_SIZE (subtype)))) |
8d326f11 | 355 | goto no_useful_type_info; |
356 | ||
357 | cur_offset = new_offset; | |
2bfdc8e7 | 358 | type = TYPE_MAIN_VARIANT (subtype); |
8d326f11 | 359 | if (!speculative) |
360 | { | |
361 | outer_type = type; | |
362 | offset = cur_offset; | |
363 | maybe_derived_type = false; | |
364 | } | |
365 | else | |
366 | { | |
367 | speculative_outer_type = type; | |
368 | speculative_offset = cur_offset; | |
369 | speculative_maybe_derived_type = false; | |
370 | } | |
371 | } | |
372 | /* Give up on anything else. */ | |
373 | else | |
374 | { | |
375 | no_useful_type_info: | |
2b7b45ca | 376 | if (maybe_derived_type && !speculative |
377 | && TREE_CODE (outer_type) == RECORD_TYPE | |
378 | && TREE_CODE (otr_type) == RECORD_TYPE | |
379 | && TYPE_BINFO (otr_type) | |
380 | && !offset | |
381 | && get_binfo_at_offset (TYPE_BINFO (otr_type), 0, outer_type)) | |
382 | { | |
383 | clear_outer_type (otr_type); | |
384 | if (!speculative_outer_type | |
385 | || !speculation_consistent_p (speculative_outer_type, | |
386 | speculative_offset, | |
387 | speculative_maybe_derived_type, | |
388 | otr_type)) | |
389 | clear_speculation (); | |
390 | if (speculative_outer_type) | |
391 | { | |
392 | speculative = true; | |
393 | type = speculative_outer_type; | |
394 | cur_offset = speculative_offset; | |
395 | } | |
396 | else | |
397 | return true; | |
398 | } | |
8d326f11 | 399 | /* We found no way to embedd EXPECTED_TYPE in TYPE. |
400 | We still permit two special cases - placement new and | |
401 | the case of variadic types containing themselves. */ | |
402 | if (!speculative | |
2b7b45ca | 403 | && consider_placement_new |
404 | && (size_unknown || !type || maybe_derived_type | |
405 | || possible_placement_new (type, otr_type, cur_offset))) | |
8d326f11 | 406 | { |
407 | /* In these weird cases we want to accept the context. | |
408 | In non-speculative run we have no useful outer_type info | |
409 | (TODO: we may eventually want to record upper bound on the | |
410 | type size that can be used to prune the walk), | |
411 | but we still want to consider speculation that may | |
412 | give useful info. */ | |
413 | if (!speculative) | |
414 | { | |
2b7b45ca | 415 | clear_outer_type (otr_type); |
416 | if (!speculative_outer_type | |
417 | || !speculation_consistent_p (speculative_outer_type, | |
418 | speculative_offset, | |
419 | speculative_maybe_derived_type, | |
420 | otr_type)) | |
421 | clear_speculation (); | |
8d326f11 | 422 | if (speculative_outer_type) |
423 | { | |
424 | speculative = true; | |
425 | type = speculative_outer_type; | |
426 | cur_offset = speculative_offset; | |
427 | } | |
428 | else | |
429 | return true; | |
430 | } | |
431 | else | |
00a8cb04 | 432 | { |
433 | clear_speculation (); | |
434 | return true; | |
435 | } | |
8d326f11 | 436 | } |
437 | else | |
438 | { | |
439 | clear_speculation (); | |
440 | if (speculative) | |
441 | return true; | |
2b7b45ca | 442 | clear_outer_type (otr_type); |
8d326f11 | 443 | invalid = true; |
444 | return false; | |
445 | } | |
446 | } | |
447 | } | |
448 | } | |
449 | ||
2b7b45ca | 450 | /* Return true if OUTER_TYPE contains OTR_TYPE at OFFSET. |
451 | CONSIDER_PLACEMENT_NEW makes function to accept cases where OTR_TYPE can | |
452 | be built within OUTER_TYPE by means of placement new. CONSIDER_BASES makes | |
453 | function to accept cases where OTR_TYPE appears as base of OUTER_TYPE or as | |
454 | base of one of fields of OUTER_TYPE. */ | |
8d326f11 | 455 | |
456 | static bool | |
457 | contains_type_p (tree outer_type, HOST_WIDE_INT offset, | |
2b7b45ca | 458 | tree otr_type, |
459 | bool consider_placement_new, | |
460 | bool consider_bases) | |
8d326f11 | 461 | { |
462 | ipa_polymorphic_call_context context; | |
2b7b45ca | 463 | |
464 | /* Check that type is within range. */ | |
465 | if (offset < 0) | |
466 | return false; | |
2b62583d | 467 | |
468 | /* PR ipa/71207 | |
469 | As OUTER_TYPE can be a type which has a diamond virtual inheritance, | |
470 | it's not necessary that INNER_TYPE will fit within OUTER_TYPE with | |
471 | a given offset. It can happen that INNER_TYPE also contains a base object, | |
472 | however it would point to the same instance in the OUTER_TYPE. */ | |
2b7b45ca | 473 | |
8d326f11 | 474 | context.offset = offset; |
475 | context.outer_type = TYPE_MAIN_VARIANT (outer_type); | |
476 | context.maybe_derived_type = false; | |
00a8cb04 | 477 | context.dynamic = false; |
478 | return context.restrict_to_inner_class (otr_type, consider_placement_new, | |
479 | consider_bases); | |
8d326f11 | 480 | } |
481 | ||
482 | ||
402d7a90 | 483 | /* Return a FUNCTION_DECL if FN represent a constructor or destructor. |
a467a47b | 484 | If CHECK_CLONES is true, also check for clones of ctor/dtors. */ |
485 | ||
486 | tree | |
402d7a90 | 487 | polymorphic_ctor_dtor_p (tree fn, bool check_clones) |
a467a47b | 488 | { |
a467a47b | 489 | if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE |
490 | || (!DECL_CXX_CONSTRUCTOR_P (fn) && !DECL_CXX_DESTRUCTOR_P (fn))) | |
491 | { | |
492 | if (!check_clones) | |
493 | return NULL_TREE; | |
494 | ||
495 | /* Watch for clones where we constant propagated the first | |
496 | argument (pointer to the instance). */ | |
497 | fn = DECL_ABSTRACT_ORIGIN (fn); | |
498 | if (!fn | |
499 | || TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE | |
500 | || (!DECL_CXX_CONSTRUCTOR_P (fn) && !DECL_CXX_DESTRUCTOR_P (fn))) | |
501 | return NULL_TREE; | |
502 | } | |
503 | ||
504 | if (flags_from_decl_or_type (fn) & (ECF_PURE | ECF_CONST)) | |
505 | return NULL_TREE; | |
506 | ||
507 | return fn; | |
508 | } | |
509 | ||
402d7a90 | 510 | /* Return a FUNCTION_DECL if BLOCK represents a constructor or destructor. |
511 | If CHECK_CLONES is true, also check for clones of ctor/dtors. */ | |
512 | ||
513 | tree | |
514 | inlined_polymorphic_ctor_dtor_block_p (tree block, bool check_clones) | |
515 | { | |
516 | tree fn = block_ultimate_origin (block); | |
517 | if (fn == NULL || TREE_CODE (fn) != FUNCTION_DECL) | |
518 | return NULL_TREE; | |
519 | ||
520 | return polymorphic_ctor_dtor_p (fn, check_clones); | |
521 | } | |
522 | ||
a467a47b | 523 | |
8d326f11 | 524 | /* We know that the instance is stored in variable or parameter |
525 | (not dynamically allocated) and we want to disprove the fact | |
526 | that it may be in construction at invocation of CALL. | |
527 | ||
714f6439 | 528 | BASE represents memory location where instance is stored. |
529 | If BASE is NULL, it is assumed to be global memory. | |
530 | OUTER_TYPE is known type of the instance or NULL if not | |
531 | known. | |
532 | ||
8d326f11 | 533 | For the variable to be in construction we actually need to |
534 | be in constructor of corresponding global variable or | |
535 | the inline stack of CALL must contain the constructor. | |
536 | Check this condition. This check works safely only before | |
537 | IPA passes, because inline stacks may become out of date | |
538 | later. */ | |
539 | ||
540 | bool | |
541 | decl_maybe_in_construction_p (tree base, tree outer_type, | |
42acab1c | 542 | gimple *call, tree function) |
8d326f11 | 543 | { |
714f6439 | 544 | if (outer_type) |
545 | outer_type = TYPE_MAIN_VARIANT (outer_type); | |
546 | gcc_assert (!base || DECL_P (base)); | |
8d326f11 | 547 | |
548 | /* After inlining the code unification optimizations may invalidate | |
549 | inline stacks. Also we need to give up on global variables after | |
550 | IPA, because addresses of these may have been propagated to their | |
551 | constructors. */ | |
552 | if (DECL_STRUCT_FUNCTION (function)->after_inlining) | |
553 | return true; | |
554 | ||
555 | /* Pure functions can not do any changes on the dynamic type; | |
556 | that require writting to memory. */ | |
714f6439 | 557 | if ((!base || !auto_var_in_fn_p (base, function)) |
8d326f11 | 558 | && flags_from_decl_or_type (function) & (ECF_PURE | ECF_CONST)) |
559 | return false; | |
560 | ||
a467a47b | 561 | bool check_clones = !base || is_global_var (base); |
8d326f11 | 562 | for (tree block = gimple_block (call); block && TREE_CODE (block) == BLOCK; |
563 | block = BLOCK_SUPERCONTEXT (block)) | |
a467a47b | 564 | if (tree fn = inlined_polymorphic_ctor_dtor_block_p (block, check_clones)) |
8d326f11 | 565 | { |
1fda15e2 | 566 | tree type = TYPE_METHOD_BASETYPE (TREE_TYPE (fn)); |
714f6439 | 567 | |
568 | if (!outer_type || !types_odr_comparable (type, outer_type)) | |
569 | { | |
570 | if (TREE_CODE (type) == RECORD_TYPE | |
571 | && TYPE_BINFO (type) | |
572 | && polymorphic_type_binfo_p (TYPE_BINFO (type))) | |
573 | return true; | |
574 | } | |
575 | else if (types_same_for_odr (type, outer_type)) | |
8d326f11 | 576 | return true; |
577 | } | |
578 | ||
53e9c5c4 | 579 | if (!base || (VAR_P (base) && is_global_var (base))) |
8d326f11 | 580 | { |
581 | if (TREE_CODE (TREE_TYPE (function)) != METHOD_TYPE | |
582 | || (!DECL_CXX_CONSTRUCTOR_P (function) | |
583 | && !DECL_CXX_DESTRUCTOR_P (function))) | |
584 | { | |
585 | if (!DECL_ABSTRACT_ORIGIN (function)) | |
586 | return false; | |
587 | /* Watch for clones where we constant propagated the first | |
588 | argument (pointer to the instance). */ | |
589 | function = DECL_ABSTRACT_ORIGIN (function); | |
590 | if (!function | |
591 | || TREE_CODE (TREE_TYPE (function)) != METHOD_TYPE | |
592 | || (!DECL_CXX_CONSTRUCTOR_P (function) | |
593 | && !DECL_CXX_DESTRUCTOR_P (function))) | |
594 | return false; | |
595 | } | |
1fda15e2 | 596 | tree type = TYPE_METHOD_BASETYPE (TREE_TYPE (function)); |
714f6439 | 597 | if (!outer_type || !types_odr_comparable (type, outer_type)) |
598 | { | |
599 | if (TREE_CODE (type) == RECORD_TYPE | |
600 | && TYPE_BINFO (type) | |
601 | && polymorphic_type_binfo_p (TYPE_BINFO (type))) | |
602 | return true; | |
603 | } | |
604 | else if (types_same_for_odr (type, outer_type)) | |
8d326f11 | 605 | return true; |
606 | } | |
607 | return false; | |
608 | } | |
609 | ||
245ab191 | 610 | /* Dump human readable context to F. If NEWLINE is true, it will be terminated |
611 | by a newline. */ | |
8d326f11 | 612 | |
613 | void | |
245ab191 | 614 | ipa_polymorphic_call_context::dump (FILE *f, bool newline) const |
8d326f11 | 615 | { |
616 | fprintf (f, " "); | |
617 | if (invalid) | |
1986ca43 | 618 | fprintf (f, "Call is known to be undefined"); |
8d326f11 | 619 | else |
620 | { | |
2b7b45ca | 621 | if (useless_p ()) |
622 | fprintf (f, "nothing known"); | |
8d326f11 | 623 | if (outer_type || offset) |
624 | { | |
c500eb01 | 625 | fprintf (f, "Outer type%s:", dynamic ? " (dynamic)":""); |
8d326f11 | 626 | print_generic_expr (f, outer_type, TDF_SLIM); |
627 | if (maybe_derived_type) | |
628 | fprintf (f, " (or a derived type)"); | |
629 | if (maybe_in_construction) | |
630 | fprintf (f, " (maybe in construction)"); | |
f03df321 | 631 | fprintf (f, " offset " HOST_WIDE_INT_PRINT_DEC, |
8d326f11 | 632 | offset); |
633 | } | |
634 | if (speculative_outer_type) | |
635 | { | |
2b7b45ca | 636 | if (outer_type || offset) |
637 | fprintf (f, " "); | |
638 | fprintf (f, "Speculative outer type:"); | |
8d326f11 | 639 | print_generic_expr (f, speculative_outer_type, TDF_SLIM); |
640 | if (speculative_maybe_derived_type) | |
641 | fprintf (f, " (or a derived type)"); | |
f03df321 | 642 | fprintf (f, " at offset " HOST_WIDE_INT_PRINT_DEC, |
8d326f11 | 643 | speculative_offset); |
644 | } | |
645 | } | |
245ab191 | 646 | if (newline) |
647 | fprintf(f, "\n"); | |
8d326f11 | 648 | } |
649 | ||
650 | /* Print context to stderr. */ | |
651 | ||
652 | void | |
653 | ipa_polymorphic_call_context::debug () const | |
654 | { | |
655 | dump (stderr); | |
656 | } | |
657 | ||
658 | /* Stream out the context to OB. */ | |
659 | ||
660 | void | |
661 | ipa_polymorphic_call_context::stream_out (struct output_block *ob) const | |
662 | { | |
663 | struct bitpack_d bp = bitpack_create (ob->main_stream); | |
664 | ||
665 | bp_pack_value (&bp, invalid, 1); | |
666 | bp_pack_value (&bp, maybe_in_construction, 1); | |
667 | bp_pack_value (&bp, maybe_derived_type, 1); | |
668 | bp_pack_value (&bp, speculative_maybe_derived_type, 1); | |
c500eb01 | 669 | bp_pack_value (&bp, dynamic, 1); |
8d326f11 | 670 | bp_pack_value (&bp, outer_type != NULL, 1); |
671 | bp_pack_value (&bp, offset != 0, 1); | |
672 | bp_pack_value (&bp, speculative_outer_type != NULL, 1); | |
673 | streamer_write_bitpack (&bp); | |
674 | ||
675 | if (outer_type != NULL) | |
676 | stream_write_tree (ob, outer_type, true); | |
677 | if (offset) | |
678 | streamer_write_hwi (ob, offset); | |
679 | if (speculative_outer_type != NULL) | |
680 | { | |
681 | stream_write_tree (ob, speculative_outer_type, true); | |
682 | streamer_write_hwi (ob, speculative_offset); | |
683 | } | |
684 | else | |
685 | gcc_assert (!speculative_offset); | |
686 | } | |
687 | ||
688 | /* Stream in the context from IB and DATA_IN. */ | |
689 | ||
690 | void | |
691 | ipa_polymorphic_call_context::stream_in (struct lto_input_block *ib, | |
692 | struct data_in *data_in) | |
693 | { | |
694 | struct bitpack_d bp = streamer_read_bitpack (ib); | |
695 | ||
696 | invalid = bp_unpack_value (&bp, 1); | |
697 | maybe_in_construction = bp_unpack_value (&bp, 1); | |
698 | maybe_derived_type = bp_unpack_value (&bp, 1); | |
699 | speculative_maybe_derived_type = bp_unpack_value (&bp, 1); | |
c500eb01 | 700 | dynamic = bp_unpack_value (&bp, 1); |
8d326f11 | 701 | bool outer_type_p = bp_unpack_value (&bp, 1); |
702 | bool offset_p = bp_unpack_value (&bp, 1); | |
703 | bool speculative_outer_type_p = bp_unpack_value (&bp, 1); | |
704 | ||
705 | if (outer_type_p) | |
706 | outer_type = stream_read_tree (ib, data_in); | |
707 | else | |
708 | outer_type = NULL; | |
709 | if (offset_p) | |
710 | offset = (HOST_WIDE_INT) streamer_read_hwi (ib); | |
711 | else | |
712 | offset = 0; | |
713 | if (speculative_outer_type_p) | |
714 | { | |
715 | speculative_outer_type = stream_read_tree (ib, data_in); | |
716 | speculative_offset = (HOST_WIDE_INT) streamer_read_hwi (ib); | |
717 | } | |
718 | else | |
719 | { | |
720 | speculative_outer_type = NULL; | |
721 | speculative_offset = 0; | |
722 | } | |
723 | } | |
724 | ||
725 | /* Proudce polymorphic call context for call method of instance | |
726 | that is located within BASE (that is assumed to be a decl) at offset OFF. */ | |
727 | ||
728 | void | |
729 | ipa_polymorphic_call_context::set_by_decl (tree base, HOST_WIDE_INT off) | |
730 | { | |
731 | gcc_assert (DECL_P (base)); | |
c500eb01 | 732 | clear_speculation (); |
8d326f11 | 733 | |
c500eb01 | 734 | if (!contains_polymorphic_type_p (TREE_TYPE (base))) |
735 | { | |
736 | clear_outer_type (); | |
737 | offset = off; | |
738 | return; | |
739 | } | |
8d326f11 | 740 | outer_type = TYPE_MAIN_VARIANT (TREE_TYPE (base)); |
741 | offset = off; | |
8d326f11 | 742 | /* Make very conservative assumption that all objects |
743 | may be in construction. | |
744 | ||
745 | It is up to caller to revisit this via | |
746 | get_dynamic_type or decl_maybe_in_construction_p. */ | |
747 | maybe_in_construction = true; | |
748 | maybe_derived_type = false; | |
c500eb01 | 749 | dynamic = false; |
8d326f11 | 750 | } |
751 | ||
752 | /* CST is an invariant (address of decl), try to get meaningful | |
753 | polymorphic call context for polymorphic call of method | |
754 | if instance of OTR_TYPE that is located at offset OFF of this invariant. | |
755 | Return FALSE if nothing meaningful can be found. */ | |
756 | ||
757 | bool | |
758 | ipa_polymorphic_call_context::set_by_invariant (tree cst, | |
759 | tree otr_type, | |
760 | HOST_WIDE_INT off) | |
761 | { | |
f3c2a387 | 762 | poly_int64 offset2, size, max_size; |
292237f3 | 763 | bool reverse; |
8d326f11 | 764 | tree base; |
765 | ||
766 | invalid = false; | |
767 | off = 0; | |
768 | clear_outer_type (otr_type); | |
769 | ||
770 | if (TREE_CODE (cst) != ADDR_EXPR) | |
771 | return false; | |
772 | ||
773 | cst = TREE_OPERAND (cst, 0); | |
292237f3 | 774 | base = get_ref_base_and_extent (cst, &offset2, &size, &max_size, &reverse); |
f3c2a387 | 775 | if (!DECL_P (base) || !known_size_p (max_size) || maybe_ne (max_size, size)) |
8d326f11 | 776 | return false; |
777 | ||
778 | /* Only type inconsistent programs can have otr_type that is | |
779 | not part of outer type. */ | |
780 | if (otr_type && !contains_type_p (TREE_TYPE (base), off, otr_type)) | |
781 | return false; | |
782 | ||
783 | set_by_decl (base, off); | |
784 | return true; | |
785 | } | |
786 | ||
787 | /* See if OP is SSA name initialized as a copy or by single assignment. | |
1986ca43 | 788 | If so, walk the SSA graph up. Because simple PHI conditional is considered |
789 | copy, GLOBAL_VISITED may be used to avoid infinite loop walking the SSA | |
790 | graph. */ | |
8d326f11 | 791 | |
792 | static tree | |
1986ca43 | 793 | walk_ssa_copies (tree op, hash_set<tree> **global_visited = NULL) |
8d326f11 | 794 | { |
1986ca43 | 795 | hash_set <tree> *visited = NULL; |
8d326f11 | 796 | STRIP_NOPS (op); |
797 | while (TREE_CODE (op) == SSA_NAME | |
798 | && !SSA_NAME_IS_DEFAULT_DEF (op) | |
9327cf31 | 799 | /* We might be called via fold_stmt during cfgcleanup where |
800 | SSA form need not be up-to-date. */ | |
801 | && !name_registered_for_update_p (op) | |
43aac8cb | 802 | && (gimple_assign_single_p (SSA_NAME_DEF_STMT (op)) |
803 | || gimple_code (SSA_NAME_DEF_STMT (op)) == GIMPLE_PHI)) | |
8d326f11 | 804 | { |
1986ca43 | 805 | if (global_visited) |
806 | { | |
807 | if (!*global_visited) | |
808 | *global_visited = new hash_set<tree>; | |
809 | if ((*global_visited)->add (op)) | |
810 | goto done; | |
811 | } | |
812 | else | |
813 | { | |
814 | if (!visited) | |
815 | visited = new hash_set<tree>; | |
816 | if (visited->add (op)) | |
817 | goto done; | |
818 | } | |
43aac8cb | 819 | /* Special case |
820 | if (ptr == 0) | |
821 | ptr = 0; | |
822 | else | |
823 | ptr = ptr.foo; | |
824 | This pattern is implicitly produced for casts to non-primary | |
825 | bases. When doing context analysis, we do not really care | |
fe4bc123 | 826 | about the case pointer is NULL, because the call will be |
43aac8cb | 827 | undefined anyway. */ |
828 | if (gimple_code (SSA_NAME_DEF_STMT (op)) == GIMPLE_PHI) | |
829 | { | |
42acab1c | 830 | gimple *phi = SSA_NAME_DEF_STMT (op); |
43aac8cb | 831 | |
9327cf31 | 832 | if (gimple_phi_num_args (phi) > 2) |
1986ca43 | 833 | goto done; |
834 | if (gimple_phi_num_args (phi) == 1) | |
835 | op = gimple_phi_arg_def (phi, 0); | |
836 | else if (integer_zerop (gimple_phi_arg_def (phi, 0))) | |
43aac8cb | 837 | op = gimple_phi_arg_def (phi, 1); |
838 | else if (integer_zerop (gimple_phi_arg_def (phi, 1))) | |
839 | op = gimple_phi_arg_def (phi, 0); | |
840 | else | |
1986ca43 | 841 | goto done; |
43aac8cb | 842 | } |
843 | else | |
844 | { | |
845 | if (gimple_assign_load_p (SSA_NAME_DEF_STMT (op))) | |
1986ca43 | 846 | goto done; |
43aac8cb | 847 | op = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (op)); |
848 | } | |
8d326f11 | 849 | STRIP_NOPS (op); |
850 | } | |
1986ca43 | 851 | done: |
852 | if (visited) | |
853 | delete (visited); | |
8d326f11 | 854 | return op; |
855 | } | |
856 | ||
857 | /* Create polymorphic call context from IP invariant CST. | |
858 | This is typically &global_var. | |
859 | OTR_TYPE specify type of polymorphic call or NULL if unknown, OFF | |
860 | is offset of call. */ | |
861 | ||
862 | ipa_polymorphic_call_context::ipa_polymorphic_call_context (tree cst, | |
863 | tree otr_type, | |
864 | HOST_WIDE_INT off) | |
865 | { | |
866 | clear_speculation (); | |
867 | set_by_invariant (cst, otr_type, off); | |
868 | } | |
869 | ||
870 | /* Build context for pointer REF contained in FNDECL at statement STMT. | |
871 | if INSTANCE is non-NULL, return pointer to the object described by | |
872 | the context or DECL where context is contained in. */ | |
873 | ||
874 | ipa_polymorphic_call_context::ipa_polymorphic_call_context (tree fndecl, | |
875 | tree ref, | |
42acab1c | 876 | gimple *stmt, |
8d326f11 | 877 | tree *instance) |
878 | { | |
879 | tree otr_type = NULL; | |
880 | tree base_pointer; | |
1986ca43 | 881 | hash_set <tree> *visited = NULL; |
8d326f11 | 882 | |
883 | if (TREE_CODE (ref) == OBJ_TYPE_REF) | |
884 | { | |
885 | otr_type = obj_type_ref_class (ref); | |
886 | base_pointer = OBJ_TYPE_REF_OBJECT (ref); | |
887 | } | |
888 | else | |
889 | base_pointer = ref; | |
890 | ||
891 | /* Set up basic info in case we find nothing interesting in the analysis. */ | |
892 | clear_speculation (); | |
893 | clear_outer_type (otr_type); | |
894 | invalid = false; | |
895 | ||
896 | /* Walk SSA for outer object. */ | |
1986ca43 | 897 | while (true) |
8d326f11 | 898 | { |
1986ca43 | 899 | base_pointer = walk_ssa_copies (base_pointer, &visited); |
8d326f11 | 900 | if (TREE_CODE (base_pointer) == ADDR_EXPR) |
901 | { | |
f3c2a387 | 902 | HOST_WIDE_INT offset2, size; |
292237f3 | 903 | bool reverse; |
904 | tree base | |
f3c2a387 | 905 | = get_ref_base_and_extent_hwi (TREE_OPERAND (base_pointer, 0), |
906 | &offset2, &size, &reverse); | |
907 | if (!base) | |
908 | break; | |
8d326f11 | 909 | |
f3c2a387 | 910 | combine_speculation_with (TYPE_MAIN_VARIANT (TREE_TYPE (base)), |
911 | offset + offset2, | |
912 | true, | |
913 | NULL /* Do not change outer type. */); | |
2b7b45ca | 914 | |
8d326f11 | 915 | /* If this is a varying address, punt. */ |
f3c2a387 | 916 | if (TREE_CODE (base) == MEM_REF || DECL_P (base)) |
8d326f11 | 917 | { |
918 | /* We found dereference of a pointer. Type of the pointer | |
919 | and MEM_REF is meaningless, but we can look futher. */ | |
90ca1268 | 920 | offset_int mem_offset; |
921 | if (TREE_CODE (base) == MEM_REF | |
922 | && mem_ref_offset (base).is_constant (&mem_offset)) | |
8d326f11 | 923 | { |
90ca1268 | 924 | offset_int o = mem_offset * BITS_PER_UNIT; |
c1172f3a | 925 | o += offset; |
926 | o += offset2; | |
927 | if (!wi::fits_shwi_p (o)) | |
928 | break; | |
8d326f11 | 929 | base_pointer = TREE_OPERAND (base, 0); |
c1172f3a | 930 | offset = o.to_shwi (); |
8d326f11 | 931 | outer_type = NULL; |
932 | } | |
933 | /* We found base object. In this case the outer_type | |
934 | is known. */ | |
935 | else if (DECL_P (base)) | |
936 | { | |
1986ca43 | 937 | if (visited) |
938 | delete (visited); | |
8d326f11 | 939 | /* Only type inconsistent programs can have otr_type that is |
940 | not part of outer type. */ | |
941 | if (otr_type | |
942 | && !contains_type_p (TREE_TYPE (base), | |
943 | offset + offset2, otr_type)) | |
944 | { | |
945 | invalid = true; | |
946 | if (instance) | |
947 | *instance = base_pointer; | |
948 | return; | |
949 | } | |
950 | set_by_decl (base, offset + offset2); | |
c500eb01 | 951 | if (outer_type && maybe_in_construction && stmt) |
8d326f11 | 952 | maybe_in_construction |
953 | = decl_maybe_in_construction_p (base, | |
954 | outer_type, | |
955 | stmt, | |
956 | fndecl); | |
957 | if (instance) | |
958 | *instance = base; | |
959 | return; | |
960 | } | |
961 | else | |
962 | break; | |
963 | } | |
964 | else | |
965 | break; | |
966 | } | |
967 | else if (TREE_CODE (base_pointer) == POINTER_PLUS_EXPR | |
c1172f3a | 968 | && TREE_CODE (TREE_OPERAND (base_pointer, 1)) == INTEGER_CST) |
8d326f11 | 969 | { |
e3d0f65c | 970 | offset_int o |
971 | = offset_int::from (wi::to_wide (TREE_OPERAND (base_pointer, 1)), | |
972 | SIGNED); | |
c1172f3a | 973 | o *= BITS_PER_UNIT; |
974 | o += offset; | |
975 | if (!wi::fits_shwi_p (o)) | |
976 | break; | |
977 | offset = o.to_shwi (); | |
8d326f11 | 978 | base_pointer = TREE_OPERAND (base_pointer, 0); |
979 | } | |
980 | else | |
981 | break; | |
982 | } | |
1986ca43 | 983 | |
984 | if (visited) | |
985 | delete (visited); | |
8d326f11 | 986 | |
987 | /* Try to determine type of the outer object. */ | |
988 | if (TREE_CODE (base_pointer) == SSA_NAME | |
989 | && SSA_NAME_IS_DEFAULT_DEF (base_pointer) | |
990 | && TREE_CODE (SSA_NAME_VAR (base_pointer)) == PARM_DECL) | |
991 | { | |
992 | /* See if parameter is THIS pointer of a method. */ | |
993 | if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE | |
994 | && SSA_NAME_VAR (base_pointer) == DECL_ARGUMENTS (fndecl)) | |
995 | { | |
996 | outer_type | |
997 | = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (base_pointer))); | |
2b7b45ca | 998 | gcc_assert (TREE_CODE (outer_type) == RECORD_TYPE |
999 | || TREE_CODE (outer_type) == UNION_TYPE); | |
8d326f11 | 1000 | |
1001 | /* Dynamic casting has possibly upcasted the type | |
1002 | in the hiearchy. In this case outer type is less | |
1003 | informative than inner type and we should forget | |
1004 | about it. */ | |
2b7b45ca | 1005 | if ((otr_type |
1006 | && !contains_type_p (outer_type, offset, | |
1007 | otr_type)) | |
1008 | || !contains_polymorphic_type_p (outer_type)) | |
8d326f11 | 1009 | { |
1010 | outer_type = NULL; | |
1011 | if (instance) | |
1012 | *instance = base_pointer; | |
1013 | return; | |
1014 | } | |
1015 | ||
c500eb01 | 1016 | dynamic = true; |
1017 | ||
8d326f11 | 1018 | /* If the function is constructor or destructor, then |
1019 | the type is possibly in construction, but we know | |
1020 | it is not derived type. */ | |
1021 | if (DECL_CXX_CONSTRUCTOR_P (fndecl) | |
1022 | || DECL_CXX_DESTRUCTOR_P (fndecl)) | |
1023 | { | |
1024 | maybe_in_construction = true; | |
1025 | maybe_derived_type = false; | |
1026 | } | |
1027 | else | |
1028 | { | |
1029 | maybe_derived_type = true; | |
1030 | maybe_in_construction = false; | |
1031 | } | |
1032 | if (instance) | |
1033 | *instance = base_pointer; | |
1034 | return; | |
1035 | } | |
1036 | /* Non-PODs passed by value are really passed by invisible | |
1037 | reference. In this case we also know the type of the | |
1038 | object. */ | |
1039 | if (DECL_BY_REFERENCE (SSA_NAME_VAR (base_pointer))) | |
1040 | { | |
1041 | outer_type | |
1042 | = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (base_pointer))); | |
8d326f11 | 1043 | /* Only type inconsistent programs can have otr_type that is |
1044 | not part of outer type. */ | |
2b7b45ca | 1045 | if (otr_type && !contains_type_p (outer_type, offset, |
1046 | otr_type)) | |
8d326f11 | 1047 | { |
1048 | invalid = true; | |
1049 | if (instance) | |
1050 | *instance = base_pointer; | |
1051 | return; | |
1052 | } | |
2b7b45ca | 1053 | /* Non-polymorphic types have no interest for us. */ |
1054 | else if (!otr_type && !contains_polymorphic_type_p (outer_type)) | |
1055 | { | |
1056 | outer_type = NULL; | |
1057 | if (instance) | |
1058 | *instance = base_pointer; | |
1059 | return; | |
1060 | } | |
8d326f11 | 1061 | maybe_derived_type = false; |
1062 | maybe_in_construction = false; | |
1063 | if (instance) | |
1064 | *instance = base_pointer; | |
1065 | return; | |
1066 | } | |
1067 | } | |
1068 | ||
1069 | tree base_type = TREE_TYPE (base_pointer); | |
1070 | ||
1071 | if (TREE_CODE (base_pointer) == SSA_NAME | |
1072 | && SSA_NAME_IS_DEFAULT_DEF (base_pointer) | |
fdeed9df | 1073 | && !(TREE_CODE (SSA_NAME_VAR (base_pointer)) == PARM_DECL |
1074 | || TREE_CODE (SSA_NAME_VAR (base_pointer)) == RESULT_DECL)) | |
8d326f11 | 1075 | { |
1076 | invalid = true; | |
1077 | if (instance) | |
1078 | *instance = base_pointer; | |
1079 | return; | |
1080 | } | |
1081 | if (TREE_CODE (base_pointer) == SSA_NAME | |
1082 | && SSA_NAME_DEF_STMT (base_pointer) | |
1083 | && gimple_assign_single_p (SSA_NAME_DEF_STMT (base_pointer))) | |
1084 | base_type = TREE_TYPE (gimple_assign_rhs1 | |
1085 | (SSA_NAME_DEF_STMT (base_pointer))); | |
1086 | ||
41a1ab48 | 1087 | if (base_type && POINTER_TYPE_P (base_type)) |
2b7b45ca | 1088 | combine_speculation_with (TYPE_MAIN_VARIANT (TREE_TYPE (base_type)), |
1089 | offset, | |
1090 | true, NULL /* Do not change type here */); | |
8d326f11 | 1091 | /* TODO: There are multiple ways to derive a type. For instance |
1092 | if BASE_POINTER is passed to an constructor call prior our refernece. | |
1093 | We do not make this type of flow sensitive analysis yet. */ | |
1094 | if (instance) | |
1095 | *instance = base_pointer; | |
1096 | return; | |
1097 | } | |
1098 | ||
1099 | /* Structure to be passed in between detect_type_change and | |
1100 | check_stmt_for_type_change. */ | |
1101 | ||
1102 | struct type_change_info | |
1103 | { | |
1104 | /* Offset into the object where there is the virtual method pointer we are | |
1105 | looking for. */ | |
1106 | HOST_WIDE_INT offset; | |
1107 | /* The declaration or SSA_NAME pointer of the base that we are checking for | |
1108 | type change. */ | |
1109 | tree instance; | |
1110 | /* The reference to virtual table pointer used. */ | |
1111 | tree vtbl_ptr_ref; | |
1112 | tree otr_type; | |
1113 | /* If we actually can tell the type that the object has changed to, it is | |
1114 | stored in this field. Otherwise it remains NULL_TREE. */ | |
1115 | tree known_current_type; | |
1116 | HOST_WIDE_INT known_current_offset; | |
1117 | ||
1140bac5 | 1118 | /* Set to nonzero if we possibly missed some dynamic type changes and we |
1119 | should consider the set to be speculative. */ | |
1120 | unsigned speculative; | |
1121 | ||
8d326f11 | 1122 | /* Set to true if dynamic type change has been detected. */ |
1123 | bool type_maybe_changed; | |
1124 | /* Set to true if multiple types have been encountered. known_current_type | |
1125 | must be disregarded in that case. */ | |
1126 | bool multiple_types_encountered; | |
8d326f11 | 1127 | bool seen_unanalyzed_store; |
1128 | }; | |
1129 | ||
1130 | /* Return true if STMT is not call and can modify a virtual method table pointer. | |
1131 | We take advantage of fact that vtable stores must appear within constructor | |
1132 | and destructor functions. */ | |
1133 | ||
1134 | static bool | |
42acab1c | 1135 | noncall_stmt_may_be_vtbl_ptr_store (gimple *stmt) |
8d326f11 | 1136 | { |
1137 | if (is_gimple_assign (stmt)) | |
1138 | { | |
1139 | tree lhs = gimple_assign_lhs (stmt); | |
1140 | ||
1141 | if (gimple_clobber_p (stmt)) | |
1142 | return false; | |
1143 | if (!AGGREGATE_TYPE_P (TREE_TYPE (lhs))) | |
1144 | { | |
1145 | if (flag_strict_aliasing | |
1146 | && !POINTER_TYPE_P (TREE_TYPE (lhs))) | |
1147 | return false; | |
1148 | ||
1149 | if (TREE_CODE (lhs) == COMPONENT_REF | |
1150 | && !DECL_VIRTUAL_P (TREE_OPERAND (lhs, 1))) | |
1151 | return false; | |
73fd9521 | 1152 | /* In the future we might want to use get_ref_base_and_extent to find |
8d326f11 | 1153 | if there is a field corresponding to the offset and if so, proceed |
1154 | almost like if it was a component ref. */ | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | /* Code unification may mess with inline stacks. */ | |
1159 | if (cfun->after_inlining) | |
1160 | return true; | |
1161 | ||
1162 | /* Walk the inline stack and watch out for ctors/dtors. | |
1163 | TODO: Maybe we can require the store to appear in toplevel | |
1164 | block of CTOR/DTOR. */ | |
1165 | for (tree block = gimple_block (stmt); block && TREE_CODE (block) == BLOCK; | |
1166 | block = BLOCK_SUPERCONTEXT (block)) | |
1167 | if (BLOCK_ABSTRACT_ORIGIN (block) | |
3634f8ff | 1168 | && TREE_CODE (block_ultimate_origin (block)) == FUNCTION_DECL) |
a467a47b | 1169 | return inlined_polymorphic_ctor_dtor_block_p (block, false); |
8d326f11 | 1170 | return (TREE_CODE (TREE_TYPE (current_function_decl)) == METHOD_TYPE |
1171 | && (DECL_CXX_CONSTRUCTOR_P (current_function_decl) | |
1172 | || DECL_CXX_DESTRUCTOR_P (current_function_decl))); | |
1173 | } | |
1174 | ||
1175 | /* If STMT can be proved to be an assignment to the virtual method table | |
1176 | pointer of ANALYZED_OBJ and the type associated with the new table | |
dc235676 | 1177 | identified, return the type. Otherwise return NULL_TREE if type changes |
1178 | in unknown way or ERROR_MARK_NODE if type is unchanged. */ | |
8d326f11 | 1179 | |
1180 | static tree | |
42acab1c | 1181 | extr_type_from_vtbl_ptr_store (gimple *stmt, struct type_change_info *tci, |
8d326f11 | 1182 | HOST_WIDE_INT *type_offset) |
1183 | { | |
f3c2a387 | 1184 | poly_int64 offset, size, max_size; |
8d326f11 | 1185 | tree lhs, rhs, base; |
292237f3 | 1186 | bool reverse; |
8d326f11 | 1187 | |
1188 | if (!gimple_assign_single_p (stmt)) | |
1189 | return NULL_TREE; | |
1190 | ||
1191 | lhs = gimple_assign_lhs (stmt); | |
1192 | rhs = gimple_assign_rhs1 (stmt); | |
1193 | if (TREE_CODE (lhs) != COMPONENT_REF | |
1194 | || !DECL_VIRTUAL_P (TREE_OPERAND (lhs, 1))) | |
1195 | { | |
1196 | if (dump_file) | |
1197 | fprintf (dump_file, " LHS is not virtual table.\n"); | |
1198 | return NULL_TREE; | |
1199 | } | |
1200 | ||
1201 | if (tci->vtbl_ptr_ref && operand_equal_p (lhs, tci->vtbl_ptr_ref, 0)) | |
1202 | ; | |
1203 | else | |
1204 | { | |
292237f3 | 1205 | base = get_ref_base_and_extent (lhs, &offset, &size, &max_size, &reverse); |
8d326f11 | 1206 | if (DECL_P (tci->instance)) |
1207 | { | |
1208 | if (base != tci->instance) | |
1209 | { | |
1210 | if (dump_file) | |
1211 | { | |
1212 | fprintf (dump_file, " base:"); | |
1213 | print_generic_expr (dump_file, base, TDF_SLIM); | |
1214 | fprintf (dump_file, " does not match instance:"); | |
1215 | print_generic_expr (dump_file, tci->instance, TDF_SLIM); | |
1216 | fprintf (dump_file, "\n"); | |
1217 | } | |
1218 | return NULL_TREE; | |
1219 | } | |
1220 | } | |
1221 | else if (TREE_CODE (base) == MEM_REF) | |
1222 | { | |
dc235676 | 1223 | if (!operand_equal_p (tci->instance, TREE_OPERAND (base, 0), 0)) |
8d326f11 | 1224 | { |
1225 | if (dump_file) | |
1226 | { | |
1227 | fprintf (dump_file, " base mem ref:"); | |
1228 | print_generic_expr (dump_file, base, TDF_SLIM); | |
dc235676 | 1229 | fprintf (dump_file, " does not match instance:"); |
8d326f11 | 1230 | print_generic_expr (dump_file, tci->instance, TDF_SLIM); |
1231 | fprintf (dump_file, "\n"); | |
1232 | } | |
1233 | return NULL_TREE; | |
1234 | } | |
dc235676 | 1235 | if (!integer_zerop (TREE_OPERAND (base, 1))) |
1236 | { | |
1237 | if (!tree_fits_shwi_p (TREE_OPERAND (base, 1))) | |
1238 | { | |
1239 | if (dump_file) | |
1240 | { | |
1241 | fprintf (dump_file, " base mem ref:"); | |
1242 | print_generic_expr (dump_file, base, TDF_SLIM); | |
1243 | fprintf (dump_file, " has non-representable offset:"); | |
1244 | print_generic_expr (dump_file, tci->instance, TDF_SLIM); | |
1245 | fprintf (dump_file, "\n"); | |
1246 | } | |
1247 | return NULL_TREE; | |
1248 | } | |
1249 | else | |
1250 | offset += tree_to_shwi (TREE_OPERAND (base, 1)) * BITS_PER_UNIT; | |
1251 | } | |
8d326f11 | 1252 | } |
1253 | else if (!operand_equal_p (tci->instance, base, 0) | |
1254 | || tci->offset) | |
1255 | { | |
1256 | if (dump_file) | |
1257 | { | |
1258 | fprintf (dump_file, " base:"); | |
1259 | print_generic_expr (dump_file, base, TDF_SLIM); | |
1260 | fprintf (dump_file, " does not match instance:"); | |
1261 | print_generic_expr (dump_file, tci->instance, TDF_SLIM); | |
1262 | fprintf (dump_file, " with offset %i\n", (int)tci->offset); | |
1263 | } | |
c5dfddcf | 1264 | return tci->offset > POINTER_SIZE ? error_mark_node : NULL_TREE; |
dc235676 | 1265 | } |
f3c2a387 | 1266 | if (maybe_ne (offset, tci->offset) |
1267 | || maybe_ne (size, POINTER_SIZE) | |
1268 | || maybe_ne (max_size, POINTER_SIZE)) | |
dc235676 | 1269 | { |
1270 | if (dump_file) | |
f3c2a387 | 1271 | { |
1272 | fprintf (dump_file, " wrong offset "); | |
1273 | print_dec (offset, dump_file); | |
1274 | fprintf (dump_file, "!=%i or size ", (int) tci->offset); | |
1275 | print_dec (size, dump_file); | |
1276 | fprintf (dump_file, "\n"); | |
1277 | } | |
1278 | return (known_le (offset + POINTER_SIZE, tci->offset) | |
1279 | || (known_size_p (max_size) | |
1280 | && known_gt (tci->offset + POINTER_SIZE, | |
1281 | offset + max_size)) | |
1282 | ? error_mark_node : NULL); | |
8d326f11 | 1283 | } |
1284 | } | |
1285 | ||
1286 | tree vtable; | |
1287 | unsigned HOST_WIDE_INT offset2; | |
1288 | ||
1289 | if (!vtable_pointer_value_to_vtable (rhs, &vtable, &offset2)) | |
1290 | { | |
1291 | if (dump_file) | |
1292 | fprintf (dump_file, " Failed to lookup binfo\n"); | |
1293 | return NULL; | |
1294 | } | |
1295 | ||
1296 | tree binfo = subbinfo_with_vtable_at_offset (TYPE_BINFO (DECL_CONTEXT (vtable)), | |
1297 | offset2, vtable); | |
1298 | if (!binfo) | |
1299 | { | |
1300 | if (dump_file) | |
1301 | fprintf (dump_file, " Construction vtable used\n"); | |
2b7b45ca | 1302 | /* FIXME: We should suport construction contexts. */ |
8d326f11 | 1303 | return NULL; |
1304 | } | |
1305 | ||
1306 | *type_offset = tree_to_shwi (BINFO_OFFSET (binfo)) * BITS_PER_UNIT; | |
1307 | return DECL_CONTEXT (vtable); | |
1308 | } | |
1309 | ||
1310 | /* Record dynamic type change of TCI to TYPE. */ | |
1311 | ||
1312 | static void | |
1313 | record_known_type (struct type_change_info *tci, tree type, HOST_WIDE_INT offset) | |
1314 | { | |
1315 | if (dump_file) | |
1316 | { | |
1317 | if (type) | |
1318 | { | |
1319 | fprintf (dump_file, " Recording type: "); | |
1320 | print_generic_expr (dump_file, type, TDF_SLIM); | |
1321 | fprintf (dump_file, " at offset %i\n", (int)offset); | |
1322 | } | |
1323 | else | |
1324 | fprintf (dump_file, " Recording unknown type\n"); | |
1325 | } | |
1326 | ||
1327 | /* If we found a constructor of type that is not polymorphic or | |
1328 | that may contain the type in question as a field (not as base), | |
1329 | restrict to the inner class first to make type matching bellow | |
1330 | happier. */ | |
1331 | if (type | |
1332 | && (offset | |
1333 | || (TREE_CODE (type) != RECORD_TYPE | |
7ef91cea | 1334 | || !TYPE_BINFO (type) |
8d326f11 | 1335 | || !polymorphic_type_binfo_p (TYPE_BINFO (type))))) |
1336 | { | |
1337 | ipa_polymorphic_call_context context; | |
1338 | ||
1339 | context.offset = offset; | |
1340 | context.outer_type = type; | |
1341 | context.maybe_in_construction = false; | |
1342 | context.maybe_derived_type = false; | |
c500eb01 | 1343 | context.dynamic = true; |
8d326f11 | 1344 | /* If we failed to find the inner type, we know that the call |
1345 | would be undefined for type produced here. */ | |
1346 | if (!context.restrict_to_inner_class (tci->otr_type)) | |
1347 | { | |
1348 | if (dump_file) | |
1349 | fprintf (dump_file, " Ignoring; does not contain otr_type\n"); | |
1350 | return; | |
1351 | } | |
1352 | /* Watch for case we reached an POD type and anticipate placement | |
1353 | new. */ | |
1354 | if (!context.maybe_derived_type) | |
1355 | { | |
1356 | type = context.outer_type; | |
1357 | offset = context.offset; | |
1358 | } | |
1359 | } | |
1360 | if (tci->type_maybe_changed | |
1361 | && (!types_same_for_odr (type, tci->known_current_type) | |
1362 | || offset != tci->known_current_offset)) | |
1363 | tci->multiple_types_encountered = true; | |
1364 | tci->known_current_type = TYPE_MAIN_VARIANT (type); | |
1365 | tci->known_current_offset = offset; | |
1366 | tci->type_maybe_changed = true; | |
1367 | } | |
1368 | ||
1140bac5 | 1369 | |
1370 | /* The maximum number of may-defs we visit when looking for a must-def | |
1371 | that changes the dynamic type in check_stmt_for_type_change. Tuned | |
1372 | after the PR12392 testcase which unlimited spends 40% time within | |
1373 | these alias walks and 8% with the following limit. */ | |
1374 | ||
1375 | static inline bool | |
1376 | csftc_abort_walking_p (unsigned speculative) | |
1377 | { | |
1378 | unsigned max = PARAM_VALUE (PARAM_MAX_SPECULATIVE_DEVIRT_MAYDEFS); | |
1379 | return speculative > max ? true : false; | |
1380 | } | |
1381 | ||
8d326f11 | 1382 | /* Callback of walk_aliased_vdefs and a helper function for |
1383 | detect_type_change to check whether a particular statement may modify | |
1384 | the virtual table pointer, and if possible also determine the new type of | |
1385 | the (sub-)object. It stores its result into DATA, which points to a | |
1386 | type_change_info structure. */ | |
1387 | ||
1388 | static bool | |
1389 | check_stmt_for_type_change (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef, void *data) | |
1390 | { | |
42acab1c | 1391 | gimple *stmt = SSA_NAME_DEF_STMT (vdef); |
8d326f11 | 1392 | struct type_change_info *tci = (struct type_change_info *) data; |
1393 | tree fn; | |
1394 | ||
1395 | /* If we already gave up, just terminate the rest of walk. */ | |
1396 | if (tci->multiple_types_encountered) | |
1397 | return true; | |
1398 | ||
1399 | if (is_gimple_call (stmt)) | |
1400 | { | |
1401 | if (gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE)) | |
1402 | return false; | |
1403 | ||
1404 | /* Check for a constructor call. */ | |
1405 | if ((fn = gimple_call_fndecl (stmt)) != NULL_TREE | |
1406 | && DECL_CXX_CONSTRUCTOR_P (fn) | |
1407 | && TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE | |
1408 | && gimple_call_num_args (stmt)) | |
1409 | { | |
1410 | tree op = walk_ssa_copies (gimple_call_arg (stmt, 0)); | |
1fda15e2 | 1411 | tree type = TYPE_METHOD_BASETYPE (TREE_TYPE (fn)); |
f3c2a387 | 1412 | HOST_WIDE_INT offset = 0; |
292237f3 | 1413 | bool reverse; |
8d326f11 | 1414 | |
1415 | if (dump_file) | |
1416 | { | |
1417 | fprintf (dump_file, " Checking constructor call: "); | |
1ffa4346 | 1418 | print_gimple_stmt (dump_file, stmt, 0); |
8d326f11 | 1419 | } |
1420 | ||
1421 | /* See if THIS parameter seems like instance pointer. */ | |
1422 | if (TREE_CODE (op) == ADDR_EXPR) | |
1423 | { | |
f3c2a387 | 1424 | HOST_WIDE_INT size; |
1425 | op = get_ref_base_and_extent_hwi (TREE_OPERAND (op, 0), | |
1426 | &offset, &size, &reverse); | |
1427 | if (!op) | |
8d326f11 | 1428 | { |
1140bac5 | 1429 | tci->speculative++; |
1430 | return csftc_abort_walking_p (tci->speculative); | |
8d326f11 | 1431 | } |
f3c2a387 | 1432 | if (TREE_CODE (op) == MEM_REF) |
8d326f11 | 1433 | { |
1434 | if (!tree_fits_shwi_p (TREE_OPERAND (op, 1))) | |
1435 | { | |
1140bac5 | 1436 | tci->speculative++; |
1437 | return csftc_abort_walking_p (tci->speculative); | |
8d326f11 | 1438 | } |
1439 | offset += tree_to_shwi (TREE_OPERAND (op, 1)) | |
1440 | * BITS_PER_UNIT; | |
1441 | op = TREE_OPERAND (op, 0); | |
1442 | } | |
1443 | else if (DECL_P (op)) | |
1444 | ; | |
1445 | else | |
1446 | { | |
1140bac5 | 1447 | tci->speculative++; |
1448 | return csftc_abort_walking_p (tci->speculative); | |
8d326f11 | 1449 | } |
1450 | op = walk_ssa_copies (op); | |
1451 | } | |
1452 | if (operand_equal_p (op, tci->instance, 0) | |
1453 | && TYPE_SIZE (type) | |
1454 | && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST | |
1455 | && tree_fits_shwi_p (TYPE_SIZE (type)) | |
edbc08a8 | 1456 | && tree_to_shwi (TYPE_SIZE (type)) + offset > tci->offset |
1457 | /* Some inlined constructors may look as follows: | |
1458 | _3 = operator new (16); | |
1459 | MEM[(struct &)_3] ={v} {CLOBBER}; | |
1460 | MEM[(struct CompositeClass *)_3]._vptr.CompositeClass | |
1461 | = &MEM[(void *)&_ZTV14CompositeClass + 16B]; | |
1462 | _7 = &MEM[(struct CompositeClass *)_3].object; | |
1463 | EmptyClass::EmptyClass (_7); | |
1464 | ||
1465 | When determining dynamic type of _3 and because we stop at first | |
1466 | dynamic type found, we would stop on EmptyClass::EmptyClass (_7). | |
1467 | In this case the emptyclass is not even polymorphic and we miss | |
1468 | it is contained in an outer type that is polymorphic. */ | |
1469 | ||
1470 | && (tci->offset == offset || contains_polymorphic_type_p (type))) | |
8d326f11 | 1471 | { |
1472 | record_known_type (tci, type, tci->offset - offset); | |
1473 | return true; | |
1474 | } | |
1475 | } | |
1476 | /* Calls may possibly change dynamic type by placement new. Assume | |
1477 | it will not happen, but make result speculative only. */ | |
1478 | if (dump_file) | |
1479 | { | |
1480 | fprintf (dump_file, " Function call may change dynamic type:"); | |
1ffa4346 | 1481 | print_gimple_stmt (dump_file, stmt, 0); |
8d326f11 | 1482 | } |
1140bac5 | 1483 | tci->speculative++; |
1484 | return csftc_abort_walking_p (tci->speculative); | |
8d326f11 | 1485 | } |
1486 | /* Check for inlined virtual table store. */ | |
1487 | else if (noncall_stmt_may_be_vtbl_ptr_store (stmt)) | |
1488 | { | |
1489 | tree type; | |
1490 | HOST_WIDE_INT offset = 0; | |
1491 | if (dump_file) | |
1492 | { | |
1493 | fprintf (dump_file, " Checking vtbl store: "); | |
1ffa4346 | 1494 | print_gimple_stmt (dump_file, stmt, 0); |
8d326f11 | 1495 | } |
1496 | ||
1497 | type = extr_type_from_vtbl_ptr_store (stmt, tci, &offset); | |
dc235676 | 1498 | if (type == error_mark_node) |
1499 | return false; | |
fcf293b0 | 1500 | gcc_assert (!type || TYPE_MAIN_VARIANT (type) == type); |
8d326f11 | 1501 | if (!type) |
1502 | { | |
1503 | if (dump_file) | |
1504 | fprintf (dump_file, " Unanalyzed store may change type.\n"); | |
1505 | tci->seen_unanalyzed_store = true; | |
1140bac5 | 1506 | tci->speculative++; |
8d326f11 | 1507 | } |
1508 | else | |
1509 | record_known_type (tci, type, offset); | |
1510 | return true; | |
1511 | } | |
1512 | else | |
1513 | return false; | |
1514 | } | |
1515 | ||
1516 | /* THIS is polymorphic call context obtained from get_polymorphic_context. | |
1517 | OTR_OBJECT is pointer to the instance returned by OBJ_TYPE_REF_OBJECT. | |
1518 | INSTANCE is pointer to the outer instance as returned by | |
1519 | get_polymorphic_context. To avoid creation of temporary expressions, | |
1520 | INSTANCE may also be an declaration of get_polymorphic_context found the | |
1521 | value to be in static storage. | |
1522 | ||
1523 | If the type of instance is not fully determined | |
1524 | (either OUTER_TYPE is unknown or MAYBE_IN_CONSTRUCTION/INCLUDE_DERIVED_TYPES | |
1525 | is set), try to walk memory writes and find the actual construction of the | |
1526 | instance. | |
1527 | ||
43aac8cb | 1528 | Return true if memory is unchanged from function entry. |
1529 | ||
8d326f11 | 1530 | We do not include this analysis in the context analysis itself, because |
1531 | it needs memory SSA to be fully built and the walk may be expensive. | |
1532 | So it is not suitable for use withing fold_stmt and similar uses. */ | |
1533 | ||
1534 | bool | |
1535 | ipa_polymorphic_call_context::get_dynamic_type (tree instance, | |
1536 | tree otr_object, | |
1537 | tree otr_type, | |
42acab1c | 1538 | gimple *call) |
8d326f11 | 1539 | { |
1540 | struct type_change_info tci; | |
1541 | ao_ref ao; | |
1542 | bool function_entry_reached = false; | |
1543 | tree instance_ref = NULL; | |
42acab1c | 1544 | gimple *stmt = call; |
8d326f11 | 1545 | /* Remember OFFSET before it is modified by restrict_to_inner_class. |
1546 | This is because we do not update INSTANCE when walking inwards. */ | |
1547 | HOST_WIDE_INT instance_offset = offset; | |
5e98110d | 1548 | tree instance_outer_type = outer_type; |
8d326f11 | 1549 | |
32de3b92 | 1550 | if (otr_type) |
1551 | otr_type = TYPE_MAIN_VARIANT (otr_type); | |
8d326f11 | 1552 | |
1553 | /* Walk into inner type. This may clear maybe_derived_type and save us | |
1554 | from useless work. It also makes later comparsions with static type | |
1555 | easier. */ | |
32de3b92 | 1556 | if (outer_type && otr_type) |
8d326f11 | 1557 | { |
1558 | if (!restrict_to_inner_class (otr_type)) | |
1559 | return false; | |
1560 | } | |
1561 | ||
1562 | if (!maybe_in_construction && !maybe_derived_type) | |
1563 | return false; | |
1564 | ||
ae7e6062 | 1565 | /* If we are in fact not looking at any object object or the instance is |
1566 | some placement new into a random load, give up straight away. */ | |
1567 | if (TREE_CODE (instance) == MEM_REF) | |
1568 | return false; | |
1569 | ||
8d326f11 | 1570 | /* We need to obtain refernce to virtual table pointer. It is better |
1571 | to look it up in the code rather than build our own. This require bit | |
1572 | of pattern matching, but we end up verifying that what we found is | |
1573 | correct. | |
1574 | ||
1575 | What we pattern match is: | |
1576 | ||
1577 | tmp = instance->_vptr.A; // vtbl ptr load | |
1578 | tmp2 = tmp[otr_token]; // vtable lookup | |
1579 | OBJ_TYPE_REF(tmp2;instance->0) (instance); | |
1580 | ||
1581 | We want to start alias oracle walk from vtbl pointer load, | |
1582 | but we may not be able to identify it, for example, when PRE moved the | |
1583 | load around. */ | |
1584 | ||
1585 | if (gimple_code (call) == GIMPLE_CALL) | |
1586 | { | |
1587 | tree ref = gimple_call_fn (call); | |
292237f3 | 1588 | bool reverse; |
8d326f11 | 1589 | |
1590 | if (TREE_CODE (ref) == OBJ_TYPE_REF) | |
1591 | { | |
1592 | ref = OBJ_TYPE_REF_EXPR (ref); | |
1593 | ref = walk_ssa_copies (ref); | |
1594 | ||
e821df4d | 1595 | /* If call target is already known, no need to do the expensive |
1596 | memory walk. */ | |
1597 | if (is_gimple_min_invariant (ref)) | |
1598 | return false; | |
1599 | ||
8d326f11 | 1600 | /* Check if definition looks like vtable lookup. */ |
1601 | if (TREE_CODE (ref) == SSA_NAME | |
1602 | && !SSA_NAME_IS_DEFAULT_DEF (ref) | |
1603 | && gimple_assign_load_p (SSA_NAME_DEF_STMT (ref)) | |
1604 | && TREE_CODE (gimple_assign_rhs1 | |
1605 | (SSA_NAME_DEF_STMT (ref))) == MEM_REF) | |
1606 | { | |
1607 | ref = get_base_address | |
1608 | (TREE_OPERAND (gimple_assign_rhs1 | |
1609 | (SSA_NAME_DEF_STMT (ref)), 0)); | |
1610 | ref = walk_ssa_copies (ref); | |
1611 | /* Find base address of the lookup and see if it looks like | |
1612 | vptr load. */ | |
1613 | if (TREE_CODE (ref) == SSA_NAME | |
1614 | && !SSA_NAME_IS_DEFAULT_DEF (ref) | |
1615 | && gimple_assign_load_p (SSA_NAME_DEF_STMT (ref))) | |
1616 | { | |
f3c2a387 | 1617 | HOST_WIDE_INT offset2, size; |
8d326f11 | 1618 | tree ref_exp = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (ref)); |
292237f3 | 1619 | tree base_ref |
f3c2a387 | 1620 | = get_ref_base_and_extent_hwi (ref_exp, &offset2, |
1621 | &size, &reverse); | |
8d326f11 | 1622 | |
7097da81 | 1623 | /* Finally verify that what we found looks like read from |
1624 | OTR_OBJECT or from INSTANCE with offset OFFSET. */ | |
8d326f11 | 1625 | if (base_ref |
1626 | && ((TREE_CODE (base_ref) == MEM_REF | |
1627 | && ((offset2 == instance_offset | |
1628 | && TREE_OPERAND (base_ref, 0) == instance) | |
7097da81 | 1629 | || (!offset2 |
1630 | && TREE_OPERAND (base_ref, 0) | |
1631 | == otr_object))) | |
8d326f11 | 1632 | || (DECL_P (instance) && base_ref == instance |
1633 | && offset2 == instance_offset))) | |
1634 | { | |
1635 | stmt = SSA_NAME_DEF_STMT (ref); | |
1636 | instance_ref = ref_exp; | |
1637 | } | |
1638 | } | |
1639 | } | |
1640 | } | |
1641 | } | |
1642 | ||
5e98110d | 1643 | /* If we failed to look up the reference in code, build our own. */ |
8d326f11 | 1644 | if (!instance_ref) |
1645 | { | |
1646 | /* If the statement in question does not use memory, we can't tell | |
1647 | anything. */ | |
1648 | if (!gimple_vuse (stmt)) | |
1649 | return false; | |
1650 | ao_ref_init_from_ptr_and_size (&ao, otr_object, NULL); | |
1651 | } | |
1652 | else | |
1653 | /* Otherwise use the real reference. */ | |
1654 | ao_ref_init (&ao, instance_ref); | |
1655 | ||
1656 | /* We look for vtbl pointer read. */ | |
1657 | ao.size = POINTER_SIZE; | |
1658 | ao.max_size = ao.size; | |
7097da81 | 1659 | /* We are looking for stores to vptr pointer within the instance of |
1660 | outer type. | |
1661 | TODO: The vptr pointer type is globally known, we probably should | |
1662 | keep it and do that even when otr_type is unknown. */ | |
32de3b92 | 1663 | if (otr_type) |
7097da81 | 1664 | { |
1665 | ao.base_alias_set | |
1666 | = get_alias_set (outer_type ? outer_type : otr_type); | |
1667 | ao.ref_alias_set | |
1668 | = get_alias_set (TREE_TYPE (BINFO_VTABLE (TYPE_BINFO (otr_type)))); | |
1669 | } | |
8d326f11 | 1670 | |
1671 | if (dump_file) | |
1672 | { | |
1673 | fprintf (dump_file, "Determining dynamic type for call: "); | |
1ffa4346 | 1674 | print_gimple_stmt (dump_file, call, 0); |
8d326f11 | 1675 | fprintf (dump_file, " Starting walk at: "); |
1ffa4346 | 1676 | print_gimple_stmt (dump_file, stmt, 0); |
8d326f11 | 1677 | fprintf (dump_file, " instance pointer: "); |
1678 | print_generic_expr (dump_file, otr_object, TDF_SLIM); | |
1679 | fprintf (dump_file, " Outer instance pointer: "); | |
1680 | print_generic_expr (dump_file, instance, TDF_SLIM); | |
5e98110d | 1681 | fprintf (dump_file, " offset: %i (bits)", (int)instance_offset); |
8d326f11 | 1682 | fprintf (dump_file, " vtbl reference: "); |
1683 | print_generic_expr (dump_file, instance_ref, TDF_SLIM); | |
1684 | fprintf (dump_file, "\n"); | |
1685 | } | |
1686 | ||
5e98110d | 1687 | tci.offset = instance_offset; |
8d326f11 | 1688 | tci.instance = instance; |
1689 | tci.vtbl_ptr_ref = instance_ref; | |
8d326f11 | 1690 | tci.known_current_type = NULL_TREE; |
1691 | tci.known_current_offset = 0; | |
1692 | tci.otr_type = otr_type; | |
1693 | tci.type_maybe_changed = false; | |
1694 | tci.multiple_types_encountered = false; | |
1140bac5 | 1695 | tci.speculative = 0; |
8d326f11 | 1696 | tci.seen_unanalyzed_store = false; |
1697 | ||
1698 | walk_aliased_vdefs (&ao, gimple_vuse (stmt), check_stmt_for_type_change, | |
1699 | &tci, NULL, &function_entry_reached); | |
1700 | ||
1701 | /* If we did not find any type changing statements, we may still drop | |
1702 | maybe_in_construction flag if the context already have outer type. | |
1703 | ||
1704 | Here we make special assumptions about both constructors and | |
1705 | destructors which are all the functions that are allowed to alter the | |
1706 | VMT pointers. It assumes that destructors begin with assignment into | |
1707 | all VMT pointers and that constructors essentially look in the | |
1708 | following way: | |
1709 | ||
1710 | 1) The very first thing they do is that they call constructors of | |
1711 | ancestor sub-objects that have them. | |
1712 | ||
1713 | 2) Then VMT pointers of this and all its ancestors is set to new | |
1714 | values corresponding to the type corresponding to the constructor. | |
1715 | ||
1716 | 3) Only afterwards, other stuff such as constructor of member | |
1717 | sub-objects and the code written by the user is run. Only this may | |
1718 | include calling virtual functions, directly or indirectly. | |
1719 | ||
1720 | 4) placement new can not be used to change type of non-POD statically | |
1721 | allocated variables. | |
1722 | ||
1723 | There is no way to call a constructor of an ancestor sub-object in any | |
1724 | other way. | |
1725 | ||
1726 | This means that we do not have to care whether constructors get the | |
1727 | correct type information because they will always change it (in fact, | |
1728 | if we define the type to be given by the VMT pointer, it is undefined). | |
1729 | ||
1730 | The most important fact to derive from the above is that if, for some | |
1731 | statement in the section 3, we try to detect whether the dynamic type | |
1732 | has changed, we can safely ignore all calls as we examine the function | |
1733 | body backwards until we reach statements in section 2 because these | |
1734 | calls cannot be ancestor constructors or destructors (if the input is | |
1735 | not bogus) and so do not change the dynamic type (this holds true only | |
1736 | for automatically allocated objects but at the moment we devirtualize | |
1737 | only these). We then must detect that statements in section 2 change | |
1738 | the dynamic type and can try to derive the new type. That is enough | |
1739 | and we can stop, we will never see the calls into constructors of | |
1740 | sub-objects in this code. | |
1741 | ||
1742 | Therefore if the static outer type was found (outer_type) | |
1743 | we can safely ignore tci.speculative that is set on calls and give up | |
1744 | only if there was dyanmic type store that may affect given variable | |
1745 | (seen_unanalyzed_store) */ | |
1746 | ||
1747 | if (!tci.type_maybe_changed | |
1748 | || (outer_type | |
c500eb01 | 1749 | && !dynamic |
8d326f11 | 1750 | && !tci.seen_unanalyzed_store |
1751 | && !tci.multiple_types_encountered | |
5e98110d | 1752 | && ((offset == tci.offset |
1753 | && types_same_for_odr (tci.known_current_type, | |
1754 | outer_type)) | |
1755 | || (instance_offset == offset | |
1756 | && types_same_for_odr (tci.known_current_type, | |
1757 | instance_outer_type))))) | |
8d326f11 | 1758 | { |
1759 | if (!outer_type || tci.seen_unanalyzed_store) | |
1760 | return false; | |
1761 | if (maybe_in_construction) | |
1762 | maybe_in_construction = false; | |
1763 | if (dump_file) | |
1764 | fprintf (dump_file, " No dynamic type change found.\n"); | |
1765 | return true; | |
1766 | } | |
1767 | ||
1768 | if (tci.known_current_type | |
1769 | && !function_entry_reached | |
1770 | && !tci.multiple_types_encountered) | |
1771 | { | |
1772 | if (!tci.speculative) | |
1773 | { | |
1774 | outer_type = TYPE_MAIN_VARIANT (tci.known_current_type); | |
1775 | offset = tci.known_current_offset; | |
c500eb01 | 1776 | dynamic = true; |
8d326f11 | 1777 | maybe_in_construction = false; |
1778 | maybe_derived_type = false; | |
1779 | if (dump_file) | |
1780 | fprintf (dump_file, " Determined dynamic type.\n"); | |
1781 | } | |
1782 | else if (!speculative_outer_type | |
1783 | || speculative_maybe_derived_type) | |
1784 | { | |
1785 | speculative_outer_type = TYPE_MAIN_VARIANT (tci.known_current_type); | |
1786 | speculative_offset = tci.known_current_offset; | |
1787 | speculative_maybe_derived_type = false; | |
1788 | if (dump_file) | |
1789 | fprintf (dump_file, " Determined speculative dynamic type.\n"); | |
1790 | } | |
1791 | } | |
1792 | else if (dump_file) | |
1793 | { | |
1794 | fprintf (dump_file, " Found multiple types%s%s\n", | |
1795 | function_entry_reached ? " (function entry reached)" : "", | |
1796 | function_entry_reached ? " (multiple types encountered)" : ""); | |
1797 | } | |
1798 | ||
43aac8cb | 1799 | return false; |
8d326f11 | 1800 | } |
1801 | ||
2b7b45ca | 1802 | /* See if speculation given by SPEC_OUTER_TYPE, SPEC_OFFSET and SPEC_MAYBE_DERIVED_TYPE |
1803 | seems consistent (and useful) with what we already have in the non-speculative context. */ | |
1804 | ||
1805 | bool | |
1806 | ipa_polymorphic_call_context::speculation_consistent_p (tree spec_outer_type, | |
1807 | HOST_WIDE_INT spec_offset, | |
1808 | bool spec_maybe_derived_type, | |
9a271891 | 1809 | tree otr_type) const |
2b7b45ca | 1810 | { |
1811 | if (!flag_devirtualize_speculatively) | |
1812 | return false; | |
c500eb01 | 1813 | |
1814 | /* Non-polymorphic types are useless for deriving likely polymorphic | |
1815 | call targets. */ | |
1816 | if (!spec_outer_type || !contains_polymorphic_type_p (spec_outer_type)) | |
1817 | return false; | |
1818 | ||
2b7b45ca | 1819 | /* If we know nothing, speculation is always good. */ |
1820 | if (!outer_type) | |
1821 | return true; | |
1822 | ||
1823 | /* Speculation is only useful to avoid derived types. | |
1824 | This is not 100% true for placement new, where the outer context may | |
1825 | turn out to be useless, but ignore these for now. */ | |
1826 | if (!maybe_derived_type) | |
1827 | return false; | |
1828 | ||
1829 | /* If types agrees, speculation is consistent, but it makes sense only | |
1830 | when it says something new. */ | |
1831 | if (types_must_be_same_for_odr (spec_outer_type, outer_type)) | |
1832 | return maybe_derived_type && !spec_maybe_derived_type; | |
1833 | ||
2b7b45ca | 1834 | /* If speculation does not contain the type in question, ignore it. */ |
1835 | if (otr_type | |
1836 | && !contains_type_p (spec_outer_type, spec_offset, otr_type, false, true)) | |
1837 | return false; | |
1838 | ||
1839 | /* If outer type already contains speculation as a filed, | |
1840 | it is useless. We already know from OUTER_TYPE | |
1841 | SPEC_TYPE and that it is not in the construction. */ | |
1842 | if (contains_type_p (outer_type, offset - spec_offset, | |
1843 | spec_outer_type, false, false)) | |
1844 | return false; | |
1845 | ||
1846 | /* If speculative outer type is not more specified than outer | |
1847 | type, just give up. | |
1848 | We can only decide this safely if we can compare types with OUTER_TYPE. | |
1849 | */ | |
1850 | if ((!in_lto_p || odr_type_p (outer_type)) | |
1851 | && !contains_type_p (spec_outer_type, | |
1852 | spec_offset - offset, | |
1853 | outer_type, false)) | |
1854 | return false; | |
1855 | return true; | |
1856 | } | |
1857 | ||
1858 | /* Improve THIS with speculation described by NEW_OUTER_TYPE, NEW_OFFSET, | |
1859 | NEW_MAYBE_DERIVED_TYPE | |
1860 | If OTR_TYPE is set, assume the context is used with OTR_TYPE. */ | |
1861 | ||
1862 | bool | |
1863 | ipa_polymorphic_call_context::combine_speculation_with | |
1864 | (tree new_outer_type, HOST_WIDE_INT new_offset, bool new_maybe_derived_type, | |
1865 | tree otr_type) | |
1866 | { | |
1867 | if (!new_outer_type) | |
1868 | return false; | |
1869 | ||
1870 | /* restrict_to_inner_class may eliminate wrong speculation making our job | |
1871 | easeier. */ | |
1872 | if (otr_type) | |
1873 | restrict_to_inner_class (otr_type); | |
1874 | ||
1875 | if (!speculation_consistent_p (new_outer_type, new_offset, | |
1876 | new_maybe_derived_type, otr_type)) | |
1877 | return false; | |
1878 | ||
1879 | /* New speculation is a win in case we have no speculation or new | |
1880 | speculation does not consider derivations. */ | |
1881 | if (!speculative_outer_type | |
1882 | || (speculative_maybe_derived_type | |
1883 | && !new_maybe_derived_type)) | |
1884 | { | |
1885 | speculative_outer_type = new_outer_type; | |
1886 | speculative_offset = new_offset; | |
1887 | speculative_maybe_derived_type = new_maybe_derived_type; | |
1888 | return true; | |
1889 | } | |
1890 | else if (types_must_be_same_for_odr (speculative_outer_type, | |
1891 | new_outer_type)) | |
1892 | { | |
1893 | if (speculative_offset != new_offset) | |
1894 | { | |
1895 | /* OK we have two contexts that seems valid but they disagree, | |
1896 | just give up. | |
1897 | ||
1898 | This is not a lattice operation, so we may want to drop it later. */ | |
1899 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1900 | fprintf (dump_file, | |
1901 | "Speculative outer types match, " | |
1902 | "offset mismatch -> invalid speculation\n"); | |
1903 | clear_speculation (); | |
1904 | return true; | |
1905 | } | |
1906 | else | |
1907 | { | |
1908 | if (speculative_maybe_derived_type && !new_maybe_derived_type) | |
1909 | { | |
1910 | speculative_maybe_derived_type = false; | |
1911 | return true; | |
1912 | } | |
1913 | else | |
1914 | return false; | |
1915 | } | |
1916 | } | |
1917 | /* Choose type that contains the other. This one either contains the outer | |
1918 | as a field (thus giving exactly one target) or is deeper in the type | |
1919 | hiearchy. */ | |
1920 | else if (speculative_outer_type | |
1921 | && speculative_maybe_derived_type | |
1922 | && (new_offset > speculative_offset | |
1923 | || (new_offset == speculative_offset | |
1924 | && contains_type_p (new_outer_type, | |
1925 | 0, speculative_outer_type, false)))) | |
1926 | { | |
1927 | tree old_outer_type = speculative_outer_type; | |
1928 | HOST_WIDE_INT old_offset = speculative_offset; | |
1929 | bool old_maybe_derived_type = speculative_maybe_derived_type; | |
1930 | ||
1931 | speculative_outer_type = new_outer_type; | |
1932 | speculative_offset = new_offset; | |
1933 | speculative_maybe_derived_type = new_maybe_derived_type; | |
1934 | ||
1935 | if (otr_type) | |
1936 | restrict_to_inner_class (otr_type); | |
1937 | ||
1938 | /* If the speculation turned out to make no sense, revert to sensible | |
1939 | one. */ | |
1940 | if (!speculative_outer_type) | |
1941 | { | |
1942 | speculative_outer_type = old_outer_type; | |
1943 | speculative_offset = old_offset; | |
1944 | speculative_maybe_derived_type = old_maybe_derived_type; | |
1945 | return false; | |
1946 | } | |
1947 | return (old_offset != speculative_offset | |
1948 | || old_maybe_derived_type != speculative_maybe_derived_type | |
1949 | || types_must_be_same_for_odr (speculative_outer_type, | |
1950 | new_outer_type)); | |
1951 | } | |
1952 | return false; | |
1953 | } | |
1954 | ||
9a271891 | 1955 | /* Make speculation less specific so |
1956 | NEW_OUTER_TYPE, NEW_OFFSET, NEW_MAYBE_DERIVED_TYPE is also included. | |
1957 | If OTR_TYPE is set, assume the context is used with OTR_TYPE. */ | |
1958 | ||
1959 | bool | |
1960 | ipa_polymorphic_call_context::meet_speculation_with | |
1961 | (tree new_outer_type, HOST_WIDE_INT new_offset, bool new_maybe_derived_type, | |
1962 | tree otr_type) | |
1963 | { | |
1964 | if (!new_outer_type && speculative_outer_type) | |
1965 | { | |
1966 | clear_speculation (); | |
1967 | return true; | |
1968 | } | |
1969 | ||
1970 | /* restrict_to_inner_class may eliminate wrong speculation making our job | |
1971 | easeier. */ | |
1972 | if (otr_type) | |
1973 | restrict_to_inner_class (otr_type); | |
1974 | ||
1975 | if (!speculative_outer_type | |
1976 | || !speculation_consistent_p (speculative_outer_type, | |
1977 | speculative_offset, | |
1978 | speculative_maybe_derived_type, | |
1979 | otr_type)) | |
1980 | return false; | |
1981 | ||
1982 | if (!speculation_consistent_p (new_outer_type, new_offset, | |
1983 | new_maybe_derived_type, otr_type)) | |
1984 | { | |
1985 | clear_speculation (); | |
1986 | return true; | |
1987 | } | |
1988 | ||
1989 | else if (types_must_be_same_for_odr (speculative_outer_type, | |
1990 | new_outer_type)) | |
1991 | { | |
1992 | if (speculative_offset != new_offset) | |
1993 | { | |
1994 | clear_speculation (); | |
1995 | return true; | |
1996 | } | |
1997 | else | |
1998 | { | |
1999 | if (!speculative_maybe_derived_type && new_maybe_derived_type) | |
2000 | { | |
2001 | speculative_maybe_derived_type = true; | |
2002 | return true; | |
2003 | } | |
2004 | else | |
2005 | return false; | |
2006 | } | |
2007 | } | |
2008 | /* See if one type contains the other as a field (not base). */ | |
2009 | else if (contains_type_p (new_outer_type, new_offset - speculative_offset, | |
2010 | speculative_outer_type, false, false)) | |
2011 | return false; | |
2012 | else if (contains_type_p (speculative_outer_type, | |
2013 | speculative_offset - new_offset, | |
2014 | new_outer_type, false, false)) | |
2015 | { | |
2016 | speculative_outer_type = new_outer_type; | |
2017 | speculative_offset = new_offset; | |
2018 | speculative_maybe_derived_type = new_maybe_derived_type; | |
2019 | return true; | |
2020 | } | |
2021 | /* See if OUTER_TYPE is base of CTX.OUTER_TYPE. */ | |
2022 | else if (contains_type_p (new_outer_type, | |
2023 | new_offset - speculative_offset, | |
2024 | speculative_outer_type, false, true)) | |
2025 | { | |
2026 | if (!speculative_maybe_derived_type) | |
2027 | { | |
2028 | speculative_maybe_derived_type = true; | |
2029 | return true; | |
2030 | } | |
2031 | return false; | |
2032 | } | |
2033 | /* See if CTX.OUTER_TYPE is base of OUTER_TYPE. */ | |
2034 | else if (contains_type_p (speculative_outer_type, | |
2035 | speculative_offset - new_offset, new_outer_type, false, true)) | |
2036 | { | |
2037 | speculative_outer_type = new_outer_type; | |
2038 | speculative_offset = new_offset; | |
2039 | speculative_maybe_derived_type = true; | |
2040 | return true; | |
2041 | } | |
2042 | else | |
2043 | { | |
2044 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2045 | fprintf (dump_file, "Giving up on speculative meet\n"); | |
2046 | clear_speculation (); | |
2047 | return true; | |
2048 | } | |
2049 | } | |
2050 | ||
2b7b45ca | 2051 | /* Assume that both THIS and a given context is valid and strenghten THIS |
2052 | if possible. Return true if any strenghtening was made. | |
2053 | If actual type the context is being used in is known, OTR_TYPE should be | |
2054 | set accordingly. This improves quality of combined result. */ | |
2055 | ||
2056 | bool | |
2057 | ipa_polymorphic_call_context::combine_with (ipa_polymorphic_call_context ctx, | |
2058 | tree otr_type) | |
2059 | { | |
2060 | bool updated = false; | |
2061 | ||
2062 | if (ctx.useless_p () || invalid) | |
2063 | return false; | |
2064 | ||
2065 | /* Restricting context to inner type makes merging easier, however do not | |
2066 | do that unless we know how the context is used (OTR_TYPE is non-NULL) */ | |
2067 | if (otr_type && !invalid && !ctx.invalid) | |
2068 | { | |
2069 | restrict_to_inner_class (otr_type); | |
2070 | ctx.restrict_to_inner_class (otr_type); | |
2071 | if(invalid) | |
2072 | return false; | |
2073 | } | |
2074 | ||
2075 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2076 | { | |
2077 | fprintf (dump_file, "Polymorphic call context combine:"); | |
2078 | dump (dump_file); | |
2079 | fprintf (dump_file, "With context: "); | |
2080 | ctx.dump (dump_file); | |
2081 | if (otr_type) | |
2082 | { | |
2083 | fprintf (dump_file, "To be used with type: "); | |
2084 | print_generic_expr (dump_file, otr_type, TDF_SLIM); | |
2085 | fprintf (dump_file, "\n"); | |
2086 | } | |
2087 | } | |
2088 | ||
2089 | /* If call is known to be invalid, we are done. */ | |
2090 | if (ctx.invalid) | |
2091 | { | |
2092 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2093 | fprintf (dump_file, "-> Invalid context\n"); | |
2094 | goto invalidate; | |
2095 | } | |
2096 | ||
2097 | if (!ctx.outer_type) | |
2098 | ; | |
2099 | else if (!outer_type) | |
2100 | { | |
2101 | outer_type = ctx.outer_type; | |
2102 | offset = ctx.offset; | |
c500eb01 | 2103 | dynamic = ctx.dynamic; |
2b7b45ca | 2104 | maybe_in_construction = ctx.maybe_in_construction; |
2105 | maybe_derived_type = ctx.maybe_derived_type; | |
2106 | updated = true; | |
2107 | } | |
2108 | /* If types are known to be same, merging is quite easy. */ | |
2109 | else if (types_must_be_same_for_odr (outer_type, ctx.outer_type)) | |
2110 | { | |
2111 | if (offset != ctx.offset | |
2112 | && TYPE_SIZE (outer_type) | |
2113 | && TREE_CODE (TYPE_SIZE (outer_type)) == INTEGER_CST) | |
2114 | { | |
2115 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2116 | fprintf (dump_file, "Outer types match, offset mismatch -> invalid\n"); | |
2117 | clear_speculation (); | |
2118 | clear_outer_type (); | |
2119 | invalid = true; | |
2120 | return true; | |
2121 | } | |
2122 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2123 | fprintf (dump_file, "Outer types match, merging flags\n"); | |
2124 | if (maybe_in_construction && !ctx.maybe_in_construction) | |
2125 | { | |
2126 | updated = true; | |
2127 | maybe_in_construction = false; | |
2128 | } | |
2129 | if (maybe_derived_type && !ctx.maybe_derived_type) | |
2130 | { | |
2131 | updated = true; | |
2132 | maybe_derived_type = false; | |
2133 | } | |
c500eb01 | 2134 | if (dynamic && !ctx.dynamic) |
2135 | { | |
2136 | updated = true; | |
2137 | dynamic = false; | |
2138 | } | |
2b7b45ca | 2139 | } |
2140 | /* If we know the type precisely, there is not much to improve. */ | |
2141 | else if (!maybe_derived_type && !maybe_in_construction | |
2142 | && !ctx.maybe_derived_type && !ctx.maybe_in_construction) | |
2143 | { | |
2144 | /* It may be easy to check if second context permits the first | |
2145 | and set INVALID otherwise. This is not easy to do in general; | |
2146 | contains_type_p may return false negatives for non-comparable | |
2147 | types. | |
2148 | ||
2149 | If OTR_TYPE is known, we however can expect that | |
2150 | restrict_to_inner_class should have discovered the same base | |
2151 | type. */ | |
2152 | if (otr_type && !ctx.maybe_in_construction && !ctx.maybe_derived_type) | |
2153 | { | |
2154 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2155 | fprintf (dump_file, "Contextes disagree -> invalid\n"); | |
2156 | goto invalidate; | |
2157 | } | |
2158 | } | |
2159 | /* See if one type contains the other as a field (not base). | |
2160 | In this case we want to choose the wider type, because it contains | |
2161 | more information. */ | |
2162 | else if (contains_type_p (ctx.outer_type, ctx.offset - offset, | |
2163 | outer_type, false, false)) | |
2164 | { | |
2165 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2166 | fprintf (dump_file, "Second type contain the first as a field\n"); | |
2167 | ||
2168 | if (maybe_derived_type) | |
2169 | { | |
2170 | outer_type = ctx.outer_type; | |
2171 | maybe_derived_type = ctx.maybe_derived_type; | |
2172 | offset = ctx.offset; | |
c500eb01 | 2173 | dynamic = ctx.dynamic; |
2b7b45ca | 2174 | updated = true; |
2175 | } | |
2176 | ||
2177 | /* If we do not know how the context is being used, we can | |
2178 | not clear MAYBE_IN_CONSTRUCTION because it may be offseted | |
2179 | to other component of OUTER_TYPE later and we know nothing | |
2180 | about it. */ | |
2181 | if (otr_type && maybe_in_construction | |
2182 | && !ctx.maybe_in_construction) | |
2183 | { | |
2184 | maybe_in_construction = false; | |
2185 | updated = true; | |
2186 | } | |
2187 | } | |
2188 | else if (contains_type_p (outer_type, offset - ctx.offset, | |
2189 | ctx.outer_type, false, false)) | |
2190 | { | |
2191 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2192 | fprintf (dump_file, "First type contain the second as a field\n"); | |
2193 | ||
2194 | if (otr_type && maybe_in_construction | |
2195 | && !ctx.maybe_in_construction) | |
2196 | { | |
2197 | maybe_in_construction = false; | |
2198 | updated = true; | |
2199 | } | |
2200 | } | |
2201 | /* See if OUTER_TYPE is base of CTX.OUTER_TYPE. */ | |
2202 | else if (contains_type_p (ctx.outer_type, | |
2203 | ctx.offset - offset, outer_type, false, true)) | |
2204 | { | |
2205 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2206 | fprintf (dump_file, "First type is base of second\n"); | |
2207 | if (!maybe_derived_type) | |
2208 | { | |
2209 | if (!ctx.maybe_in_construction | |
2210 | && types_odr_comparable (outer_type, ctx.outer_type)) | |
2211 | { | |
2212 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2213 | fprintf (dump_file, "Second context does not permit base -> invalid\n"); | |
2214 | goto invalidate; | |
2215 | } | |
2216 | } | |
2217 | /* Pick variant deeper in the hiearchy. */ | |
2218 | else | |
2219 | { | |
2220 | outer_type = ctx.outer_type; | |
2221 | maybe_in_construction = ctx.maybe_in_construction; | |
2222 | maybe_derived_type = ctx.maybe_derived_type; | |
2223 | offset = ctx.offset; | |
c500eb01 | 2224 | dynamic = ctx.dynamic; |
2b7b45ca | 2225 | updated = true; |
2226 | } | |
2227 | } | |
2228 | /* See if CTX.OUTER_TYPE is base of OUTER_TYPE. */ | |
2229 | else if (contains_type_p (outer_type, | |
2230 | offset - ctx.offset, ctx.outer_type, false, true)) | |
2231 | { | |
2232 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2233 | fprintf (dump_file, "Second type is base of first\n"); | |
2234 | if (!ctx.maybe_derived_type) | |
2235 | { | |
2236 | if (!maybe_in_construction | |
2237 | && types_odr_comparable (outer_type, ctx.outer_type)) | |
2238 | { | |
2239 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2240 | fprintf (dump_file, "First context does not permit base -> invalid\n"); | |
2241 | goto invalidate; | |
2242 | } | |
9a271891 | 2243 | /* Pick the base type. */ |
2244 | else if (maybe_in_construction) | |
2245 | { | |
2246 | outer_type = ctx.outer_type; | |
2247 | maybe_in_construction = ctx.maybe_in_construction; | |
2248 | maybe_derived_type = ctx.maybe_derived_type; | |
2249 | offset = ctx.offset; | |
2250 | dynamic = ctx.dynamic; | |
2251 | updated = true; | |
2252 | } | |
2b7b45ca | 2253 | } |
2254 | } | |
2255 | /* TODO handle merging using hiearchy. */ | |
2256 | else if (dump_file && (dump_flags & TDF_DETAILS)) | |
2257 | fprintf (dump_file, "Giving up on merge\n"); | |
2258 | ||
2259 | updated |= combine_speculation_with (ctx.speculative_outer_type, | |
2260 | ctx.speculative_offset, | |
46424518 | 2261 | ctx.speculative_maybe_derived_type, |
2b7b45ca | 2262 | otr_type); |
2263 | ||
2264 | if (updated && dump_file && (dump_flags & TDF_DETAILS)) | |
2265 | { | |
2266 | fprintf (dump_file, "Updated as: "); | |
2267 | dump (dump_file); | |
2268 | fprintf (dump_file, "\n"); | |
2269 | } | |
2270 | return updated; | |
2271 | ||
2272 | invalidate: | |
2273 | invalid = true; | |
2274 | clear_speculation (); | |
2275 | clear_outer_type (); | |
2276 | return true; | |
2277 | } | |
2278 | ||
2279 | /* Take non-speculative info, merge it with speculative and clear speculation. | |
2280 | Used when we no longer manage to keep track of actual outer type, but we | |
c500eb01 | 2281 | think it is still there. |
2282 | ||
2283 | If OTR_TYPE is set, the transformation can be done more effectively assuming | |
2284 | that context is going to be used only that way. */ | |
2b7b45ca | 2285 | |
2286 | void | |
2287 | ipa_polymorphic_call_context::make_speculative (tree otr_type) | |
2288 | { | |
2289 | tree spec_outer_type = outer_type; | |
2290 | HOST_WIDE_INT spec_offset = offset; | |
2291 | bool spec_maybe_derived_type = maybe_derived_type; | |
2292 | ||
2293 | if (invalid) | |
2294 | { | |
2295 | invalid = false; | |
2296 | clear_outer_type (); | |
2297 | clear_speculation (); | |
2298 | return; | |
2299 | } | |
2300 | if (!outer_type) | |
2301 | return; | |
2302 | clear_outer_type (); | |
2303 | combine_speculation_with (spec_outer_type, spec_offset, | |
2304 | spec_maybe_derived_type, | |
2305 | otr_type); | |
2306 | } | |
c500eb01 | 2307 | |
2308 | /* Use when we can not track dynamic type change. This speculatively assume | |
2309 | type change is not happening. */ | |
2310 | ||
2311 | void | |
714f6439 | 2312 | ipa_polymorphic_call_context::possible_dynamic_type_change (bool in_poly_cdtor, |
2313 | tree otr_type) | |
c500eb01 | 2314 | { |
2315 | if (dynamic) | |
2316 | make_speculative (otr_type); | |
714f6439 | 2317 | else if (in_poly_cdtor) |
c500eb01 | 2318 | maybe_in_construction = true; |
2319 | } | |
245ab191 | 2320 | |
2321 | /* Return TRUE if this context conveys the same information as OTHER. */ | |
2322 | ||
2323 | bool | |
2324 | ipa_polymorphic_call_context::equal_to | |
2325 | (const ipa_polymorphic_call_context &x) const | |
2326 | { | |
2327 | if (useless_p ()) | |
2328 | return x.useless_p (); | |
2329 | if (invalid) | |
2330 | return x.invalid; | |
2331 | if (x.useless_p () || x.invalid) | |
2332 | return false; | |
2333 | ||
2334 | if (outer_type) | |
2335 | { | |
2336 | if (!x.outer_type | |
2337 | || !types_odr_comparable (outer_type, x.outer_type) | |
2338 | || !types_same_for_odr (outer_type, x.outer_type) | |
2339 | || offset != x.offset | |
2340 | || maybe_in_construction != x.maybe_in_construction | |
2341 | || maybe_derived_type != x.maybe_derived_type | |
2342 | || dynamic != x.dynamic) | |
2343 | return false; | |
2344 | } | |
2345 | else if (x.outer_type) | |
2346 | return false; | |
2347 | ||
9a271891 | 2348 | |
2349 | if (speculative_outer_type | |
2350 | && speculation_consistent_p (speculative_outer_type, speculative_offset, | |
2351 | speculative_maybe_derived_type, NULL_TREE)) | |
245ab191 | 2352 | { |
9a271891 | 2353 | if (!x.speculative_outer_type) |
2354 | return false; | |
2355 | ||
2356 | if (!types_odr_comparable (speculative_outer_type, | |
2357 | x.speculative_outer_type) | |
245ab191 | 2358 | || !types_same_for_odr (speculative_outer_type, |
9a271891 | 2359 | x.speculative_outer_type) |
245ab191 | 2360 | || speculative_offset != x.speculative_offset |
2361 | || speculative_maybe_derived_type != x.speculative_maybe_derived_type) | |
2362 | return false; | |
2363 | } | |
9a271891 | 2364 | else if (x.speculative_outer_type |
2365 | && x.speculation_consistent_p (x.speculative_outer_type, | |
2366 | x.speculative_offset, | |
2367 | x.speculative_maybe_derived_type, | |
2368 | NULL)) | |
245ab191 | 2369 | return false; |
2370 | ||
2371 | return true; | |
2372 | } | |
9a271891 | 2373 | |
2374 | /* Modify context to be strictly less restrictive than CTX. */ | |
2375 | ||
2376 | bool | |
2377 | ipa_polymorphic_call_context::meet_with (ipa_polymorphic_call_context ctx, | |
2378 | tree otr_type) | |
2379 | { | |
2380 | bool updated = false; | |
2381 | ||
2382 | if (useless_p () || ctx.invalid) | |
2383 | return false; | |
2384 | ||
2385 | /* Restricting context to inner type makes merging easier, however do not | |
2386 | do that unless we know how the context is used (OTR_TYPE is non-NULL) */ | |
2387 | if (otr_type && !useless_p () && !ctx.useless_p ()) | |
2388 | { | |
2389 | restrict_to_inner_class (otr_type); | |
2390 | ctx.restrict_to_inner_class (otr_type); | |
2391 | if(invalid) | |
2392 | return false; | |
2393 | } | |
2394 | ||
2395 | if (equal_to (ctx)) | |
2396 | return false; | |
2397 | ||
2398 | if (ctx.useless_p () || invalid) | |
2399 | { | |
2400 | *this = ctx; | |
2401 | return true; | |
2402 | } | |
2403 | ||
2404 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2405 | { | |
2406 | fprintf (dump_file, "Polymorphic call context meet:"); | |
2407 | dump (dump_file); | |
2408 | fprintf (dump_file, "With context: "); | |
2409 | ctx.dump (dump_file); | |
2410 | if (otr_type) | |
2411 | { | |
2412 | fprintf (dump_file, "To be used with type: "); | |
2413 | print_generic_expr (dump_file, otr_type, TDF_SLIM); | |
2414 | fprintf (dump_file, "\n"); | |
2415 | } | |
2416 | } | |
2417 | ||
2418 | if (!dynamic && ctx.dynamic) | |
2419 | { | |
2420 | dynamic = true; | |
2421 | updated = true; | |
2422 | } | |
2423 | ||
2424 | /* If call is known to be invalid, we are done. */ | |
2425 | if (!outer_type) | |
2426 | ; | |
2427 | else if (!ctx.outer_type) | |
2428 | { | |
2429 | clear_outer_type (); | |
2430 | updated = true; | |
2431 | } | |
2432 | /* If types are known to be same, merging is quite easy. */ | |
2433 | else if (types_must_be_same_for_odr (outer_type, ctx.outer_type)) | |
2434 | { | |
2435 | if (offset != ctx.offset | |
2436 | && TYPE_SIZE (outer_type) | |
2437 | && TREE_CODE (TYPE_SIZE (outer_type)) == INTEGER_CST) | |
2438 | { | |
2439 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2440 | fprintf (dump_file, "Outer types match, offset mismatch -> clearing\n"); | |
2441 | clear_outer_type (); | |
2442 | return true; | |
2443 | } | |
2444 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2445 | fprintf (dump_file, "Outer types match, merging flags\n"); | |
2446 | if (!maybe_in_construction && ctx.maybe_in_construction) | |
2447 | { | |
2448 | updated = true; | |
2449 | maybe_in_construction = true; | |
2450 | } | |
2451 | if (!maybe_derived_type && ctx.maybe_derived_type) | |
2452 | { | |
2453 | updated = true; | |
2454 | maybe_derived_type = true; | |
2455 | } | |
2456 | if (!dynamic && ctx.dynamic) | |
2457 | { | |
2458 | updated = true; | |
2459 | dynamic = true; | |
2460 | } | |
2461 | } | |
2462 | /* See if one type contains the other as a field (not base). */ | |
2463 | else if (contains_type_p (ctx.outer_type, ctx.offset - offset, | |
2464 | outer_type, false, false)) | |
2465 | { | |
2466 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2467 | fprintf (dump_file, "Second type contain the first as a field\n"); | |
2468 | ||
2469 | /* The second type is more specified, so we keep the first. | |
2470 | We need to set DYNAMIC flag to avoid declaring context INVALID | |
2471 | of OFFSET ends up being out of range. */ | |
2472 | if (!dynamic | |
2473 | && (ctx.dynamic | |
2474 | || (!otr_type | |
2475 | && (!TYPE_SIZE (ctx.outer_type) | |
2476 | || !TYPE_SIZE (outer_type) | |
2477 | || !operand_equal_p (TYPE_SIZE (ctx.outer_type), | |
2478 | TYPE_SIZE (outer_type), 0))))) | |
2479 | { | |
2480 | dynamic = true; | |
2481 | updated = true; | |
2482 | } | |
2483 | } | |
2484 | else if (contains_type_p (outer_type, offset - ctx.offset, | |
2485 | ctx.outer_type, false, false)) | |
2486 | { | |
2487 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2488 | fprintf (dump_file, "First type contain the second as a field\n"); | |
2489 | ||
2490 | if (!dynamic | |
2491 | && (ctx.dynamic | |
2492 | || (!otr_type | |
2493 | && (!TYPE_SIZE (ctx.outer_type) | |
2494 | || !TYPE_SIZE (outer_type) | |
2495 | || !operand_equal_p (TYPE_SIZE (ctx.outer_type), | |
2496 | TYPE_SIZE (outer_type), 0))))) | |
2497 | dynamic = true; | |
2498 | outer_type = ctx.outer_type; | |
2499 | offset = ctx.offset; | |
2500 | dynamic = ctx.dynamic; | |
2501 | maybe_in_construction = ctx.maybe_in_construction; | |
2502 | maybe_derived_type = ctx.maybe_derived_type; | |
2503 | updated = true; | |
2504 | } | |
2505 | /* See if OUTER_TYPE is base of CTX.OUTER_TYPE. */ | |
2506 | else if (contains_type_p (ctx.outer_type, | |
2507 | ctx.offset - offset, outer_type, false, true)) | |
2508 | { | |
2509 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2510 | fprintf (dump_file, "First type is base of second\n"); | |
2511 | if (!maybe_derived_type) | |
2512 | { | |
2513 | maybe_derived_type = true; | |
2514 | updated = true; | |
2515 | } | |
2516 | if (!maybe_in_construction && ctx.maybe_in_construction) | |
2517 | { | |
2518 | maybe_in_construction = true; | |
2519 | updated = true; | |
2520 | } | |
2521 | if (!dynamic && ctx.dynamic) | |
2522 | { | |
2523 | dynamic = true; | |
2524 | updated = true; | |
2525 | } | |
2526 | } | |
2527 | /* See if CTX.OUTER_TYPE is base of OUTER_TYPE. */ | |
2528 | else if (contains_type_p (outer_type, | |
2529 | offset - ctx.offset, ctx.outer_type, false, true)) | |
2530 | { | |
2531 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2532 | fprintf (dump_file, "Second type is base of first\n"); | |
2533 | outer_type = ctx.outer_type; | |
2534 | offset = ctx.offset; | |
2535 | updated = true; | |
2536 | if (!maybe_derived_type) | |
2537 | maybe_derived_type = true; | |
2538 | if (!maybe_in_construction && ctx.maybe_in_construction) | |
2539 | maybe_in_construction = true; | |
2540 | if (!dynamic && ctx.dynamic) | |
2541 | dynamic = true; | |
2542 | } | |
2543 | /* TODO handle merging using hiearchy. */ | |
2544 | else | |
2545 | { | |
2546 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2547 | fprintf (dump_file, "Giving up on meet\n"); | |
2548 | clear_outer_type (); | |
2549 | updated = true; | |
2550 | } | |
2551 | ||
2552 | updated |= meet_speculation_with (ctx.speculative_outer_type, | |
2553 | ctx.speculative_offset, | |
2554 | ctx.speculative_maybe_derived_type, | |
2555 | otr_type); | |
2556 | ||
2557 | if (updated && dump_file && (dump_flags & TDF_DETAILS)) | |
2558 | { | |
2559 | fprintf (dump_file, "Updated as: "); | |
2560 | dump (dump_file); | |
2561 | fprintf (dump_file, "\n"); | |
2562 | } | |
2563 | return updated; | |
2564 | } |