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eefe9a99 JH |
1 | /* Basic IPA utilities for type inheritance graph construction and |
2 | devirtualization. | |
23a5b65a | 3 | Copyright (C) 2013-2014 Free Software Foundation, Inc. |
eefe9a99 JH |
4 | Contributed by Jan Hubicka |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 3, or (at your option) any later | |
11 | version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | /* Brief vocalburary: | |
23 | ODR = One Definition Rule | |
24 | In short, the ODR states that: | |
25 | 1 In any translation unit, a template, type, function, or object can | |
26 | have no more than one definition. Some of these can have any number | |
27 | of declarations. A definition provides an instance. | |
28 | 2 In the entire program, an object or non-inline function cannot have | |
29 | more than one definition; if an object or function is used, it must | |
30 | have exactly one definition. You can declare an object or function | |
31 | that is never used, in which case you don't have to provide | |
32 | a definition. In no event can there be more than one definition. | |
33 | 3 Some things, like types, templates, and extern inline functions, can | |
34 | be defined in more than one translation unit. For a given entity, | |
35 | each definition must be the same. Non-extern objects and functions | |
36 | in different translation units are different entities, even if their | |
37 | names and types are the same. | |
38 | ||
39 | OTR = OBJ_TYPE_REF | |
0e1474e5 | 40 | This is the Gimple representation of type information of a polymorphic call. |
eefe9a99 JH |
41 | It contains two parameters: |
42 | otr_type is a type of class whose method is called. | |
0e1474e5 | 43 | otr_token is the index into virtual table where address is taken. |
eefe9a99 JH |
44 | |
45 | BINFO | |
46 | This is the type inheritance information attached to each tree | |
47 | RECORD_TYPE by the C++ frotend. It provides information about base | |
48 | types and virtual tables. | |
49 | ||
50 | BINFO is linked to the RECORD_TYPE by TYPE_BINFO. | |
51 | BINFO also links to its type by BINFO_TYPE and to the virtual table by | |
52 | BINFO_VTABLE. | |
53 | ||
54 | Base types of a given type are enumerated by BINFO_BASE_BINFO | |
55 | vector. Members of this vectors are not BINFOs associated | |
56 | with a base type. Rather they are new copies of BINFOs | |
57 | (base BINFOs). Their virtual tables may differ from | |
0e1474e5 | 58 | virtual table of the base type. Also BINFO_OFFSET specifies |
eefe9a99 JH |
59 | offset of the base within the type. |
60 | ||
61 | In the case of single inheritance, the virtual table is shared | |
62 | and BINFO_VTABLE of base BINFO is NULL. In the case of multiple | |
63 | inheritance the individual virtual tables are pointer to by | |
64 | BINFO_VTABLE of base binfos (that differs of BINFO_VTABLE of | |
65 | binfo associated to the base type). | |
66 | ||
67 | BINFO lookup for a given base type and offset can be done by | |
68 | get_binfo_at_offset. It returns proper BINFO whose virtual table | |
69 | can be used for lookup of virtual methods associated with the | |
70 | base type. | |
71 | ||
72 | token | |
73 | This is an index of virtual method in virtual table associated | |
74 | to the type defining it. Token can be looked up from OBJ_TYPE_REF | |
0e1474e5 | 75 | or from DECL_VINDEX of a given virtual table. |
eefe9a99 JH |
76 | |
77 | polymorphic (indirect) call | |
78 | This is callgraph represention of virtual method call. Every | |
79 | polymorphic call contains otr_type and otr_token taken from | |
80 | original OBJ_TYPE_REF at callgraph construction time. | |
81 | ||
82 | What we do here: | |
83 | ||
84 | build_type_inheritance_graph triggers a construction of the type inheritance | |
85 | graph. | |
86 | ||
87 | We reconstruct it based on types of methods we see in the unit. | |
88 | This means that the graph is not complete. Types with no methods are not | |
0e1474e5 | 89 | inserted into the graph. Also types without virtual methods are not |
eefe9a99 JH |
90 | represented at all, though it may be easy to add this. |
91 | ||
92 | The inheritance graph is represented as follows: | |
93 | ||
94 | Vertices are structures odr_type. Every odr_type may correspond | |
95 | to one or more tree type nodes that are equivalent by ODR rule. | |
96 | (the multiple type nodes appear only with linktime optimization) | |
97 | ||
0e1474e5 | 98 | Edges are represented by odr_type->base and odr_type->derived_types. |
eefe9a99 JH |
99 | At the moment we do not track offsets of types for multiple inheritance. |
100 | Adding this is easy. | |
101 | ||
102 | possible_polymorphic_call_targets returns, given an parameters found in | |
103 | indirect polymorphic edge all possible polymorphic call targets of the call. | |
bbc9396b JH |
104 | |
105 | pass_ipa_devirt performs simple speculative devirtualization. | |
eefe9a99 JH |
106 | */ |
107 | ||
108 | #include "config.h" | |
109 | #include "system.h" | |
110 | #include "coretypes.h" | |
111 | #include "tm.h" | |
4d648807 | 112 | #include "tree.h" |
d8a2d370 DN |
113 | #include "print-tree.h" |
114 | #include "calls.h" | |
eefe9a99 | 115 | #include "cgraph.h" |
d8a2d370 | 116 | #include "expr.h" |
eefe9a99 | 117 | #include "tree-pass.h" |
eefe9a99 JH |
118 | #include "pointer-set.h" |
119 | #include "target.h" | |
120 | #include "hash-table.h" | |
121 | #include "tree-pretty-print.h" | |
122 | #include "ipa-utils.h" | |
2fb9a547 AM |
123 | #include "tree-ssa-alias.h" |
124 | #include "internal-fn.h" | |
125 | #include "gimple-fold.h" | |
126 | #include "gimple-expr.h" | |
eefe9a99 | 127 | #include "gimple.h" |
bbc9396b | 128 | #include "ipa-inline.h" |
61a74079 | 129 | #include "diagnostic.h" |
68377e53 | 130 | #include "tree-dfa.h" |
ec77d61f JH |
131 | #include "demangle.h" |
132 | ||
133 | static bool odr_violation_reported = false; | |
68377e53 JH |
134 | |
135 | /* Dummy polymorphic call context. */ | |
136 | ||
137 | const ipa_polymorphic_call_context ipa_dummy_polymorphic_call_context | |
138 | = {0, NULL, false, true}; | |
eefe9a99 | 139 | |
0e1474e5 JH |
140 | /* Pointer set of all call targets appearing in the cache. */ |
141 | static pointer_set_t *cached_polymorphic_call_targets; | |
142 | ||
eefe9a99 JH |
143 | /* The node of type inheritance graph. For each type unique in |
144 | One Defintion Rule (ODR) sense, we produce one node linking all | |
145 | main variants of types equivalent to it, bases and derived types. */ | |
146 | ||
147 | struct GTY(()) odr_type_d | |
148 | { | |
eefe9a99 JH |
149 | /* leader type. */ |
150 | tree type; | |
151 | /* All bases. */ | |
152 | vec<odr_type> GTY((skip)) bases; | |
153 | /* All derrived types with virtual methods seen in unit. */ | |
154 | vec<odr_type> GTY((skip)) derived_types; | |
0e1474e5 | 155 | |
61a74079 JH |
156 | /* All equivalent types, if more than one. */ |
157 | vec<tree, va_gc> *types; | |
158 | /* Set of all equivalent types, if NON-NULL. */ | |
159 | pointer_set_t * GTY((skip)) types_set; | |
160 | ||
0e1474e5 JH |
161 | /* Unique ID indexing the type in odr_types array. */ |
162 | int id; | |
eefe9a99 JH |
163 | /* Is it in anonymous namespace? */ |
164 | bool anonymous_namespace; | |
165 | }; | |
166 | ||
167 | ||
0e1474e5 JH |
168 | /* Return true if BINFO corresponds to a type with virtual methods. |
169 | ||
170 | Every type has several BINFOs. One is the BINFO associated by the type | |
171 | while other represents bases of derived types. The BINFOs representing | |
172 | bases do not have BINFO_VTABLE pointer set when this is the single | |
173 | inheritance (because vtables are shared). Look up the BINFO of type | |
174 | and check presence of its vtable. */ | |
eefe9a99 JH |
175 | |
176 | static inline bool | |
177 | polymorphic_type_binfo_p (tree binfo) | |
178 | { | |
179 | /* See if BINFO's type has an virtual table associtated with it. */ | |
180 | return BINFO_VTABLE (TYPE_BINFO (BINFO_TYPE (binfo))); | |
181 | } | |
182 | ||
183 | /* One Definition Rule hashtable helpers. */ | |
184 | ||
185 | struct odr_hasher | |
186 | { | |
187 | typedef odr_type_d value_type; | |
188 | typedef union tree_node compare_type; | |
189 | static inline hashval_t hash (const value_type *); | |
190 | static inline bool equal (const value_type *, const compare_type *); | |
191 | static inline void remove (value_type *); | |
192 | }; | |
193 | ||
194 | /* Produce hash based on type name. */ | |
195 | ||
196 | hashval_t | |
197 | hash_type_name (tree t) | |
198 | { | |
199 | gcc_checking_assert (TYPE_MAIN_VARIANT (t) == t); | |
200 | ||
201 | /* If not in LTO, all main variants are unique, so we can do | |
202 | pointer hash. */ | |
203 | if (!in_lto_p) | |
204 | return htab_hash_pointer (t); | |
205 | ||
206 | /* Anonymous types are unique. */ | |
207 | if (type_in_anonymous_namespace_p (t)) | |
208 | return htab_hash_pointer (t); | |
209 | ||
61a74079 JH |
210 | /* For polymorphic types, we can simply hash the virtual table. */ |
211 | if (TYPE_BINFO (t) && BINFO_VTABLE (TYPE_BINFO (t))) | |
212 | { | |
213 | tree v = BINFO_VTABLE (TYPE_BINFO (t)); | |
214 | hashval_t hash = 0; | |
215 | ||
216 | if (TREE_CODE (v) == POINTER_PLUS_EXPR) | |
217 | { | |
218 | hash = TREE_INT_CST_LOW (TREE_OPERAND (v, 1)); | |
219 | v = TREE_OPERAND (TREE_OPERAND (v, 0), 0); | |
220 | } | |
221 | ||
222 | v = DECL_ASSEMBLER_NAME (v); | |
61a74079 JH |
223 | hash = iterative_hash_hashval_t (hash, htab_hash_pointer (v)); |
224 | return hash; | |
225 | } | |
226 | ||
eefe9a99 JH |
227 | /* Rest is not implemented yet. */ |
228 | gcc_unreachable (); | |
229 | } | |
230 | ||
231 | /* Return the computed hashcode for ODR_TYPE. */ | |
232 | ||
233 | inline hashval_t | |
234 | odr_hasher::hash (const value_type *odr_type) | |
235 | { | |
236 | return hash_type_name (odr_type->type); | |
237 | } | |
238 | ||
0e1474e5 | 239 | /* Compare types T1 and T2 and return true if they are |
eefe9a99 JH |
240 | equivalent. */ |
241 | ||
242 | inline bool | |
243 | odr_hasher::equal (const value_type *t1, const compare_type *ct2) | |
244 | { | |
245 | tree t2 = const_cast <tree> (ct2); | |
246 | ||
247 | gcc_checking_assert (TYPE_MAIN_VARIANT (ct2) == ct2); | |
248 | if (t1->type == t2) | |
249 | return true; | |
250 | if (!in_lto_p) | |
251 | return false; | |
252 | return types_same_for_odr (t1->type, t2); | |
253 | } | |
254 | ||
0e1474e5 | 255 | /* Free ODR type V. */ |
eefe9a99 JH |
256 | |
257 | inline void | |
258 | odr_hasher::remove (value_type *v) | |
259 | { | |
260 | v->bases.release (); | |
261 | v->derived_types.release (); | |
61a74079 JH |
262 | if (v->types_set) |
263 | pointer_set_destroy (v->types_set); | |
eefe9a99 JH |
264 | ggc_free (v); |
265 | } | |
266 | ||
267 | /* ODR type hash used to lookup ODR type based on tree type node. */ | |
268 | ||
269 | typedef hash_table <odr_hasher> odr_hash_type; | |
270 | static odr_hash_type odr_hash; | |
271 | ||
272 | /* ODR types are also stored into ODR_TYPE vector to allow consistent | |
273 | walking. Bases appear before derived types. Vector is garbage collected | |
274 | so we won't end up visiting empty types. */ | |
275 | ||
276 | static GTY(()) vec <odr_type, va_gc> *odr_types_ptr; | |
277 | #define odr_types (*odr_types_ptr) | |
278 | ||
61a74079 JH |
279 | /* TYPE is equivalent to VAL by ODR, but its tree representation differs |
280 | from VAL->type. This may happen in LTO where tree merging did not merge | |
281 | all variants of the same type. It may or may not mean the ODR violation. | |
282 | Add it to the list of duplicates and warn on some violations. */ | |
283 | ||
284 | static void | |
285 | add_type_duplicate (odr_type val, tree type) | |
286 | { | |
287 | if (!val->types_set) | |
288 | val->types_set = pointer_set_create (); | |
289 | ||
290 | /* See if this duplicate is new. */ | |
291 | if (!pointer_set_insert (val->types_set, type)) | |
292 | { | |
293 | bool merge = true; | |
294 | bool base_mismatch = false; | |
295 | gcc_assert (in_lto_p); | |
296 | vec_safe_push (val->types, type); | |
297 | unsigned int i,j; | |
298 | ||
299 | /* First we compare memory layout. */ | |
300 | if (!types_compatible_p (val->type, type)) | |
301 | { | |
302 | merge = false; | |
ec77d61f | 303 | odr_violation_reported = true; |
61a74079 JH |
304 | if (BINFO_VTABLE (TYPE_BINFO (val->type)) |
305 | && warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (type)), 0, | |
306 | "type %qD violates one definition rule ", | |
307 | type)) | |
308 | inform (DECL_SOURCE_LOCATION (TYPE_NAME (val->type)), | |
309 | "a type with the same name but different layout is " | |
310 | "defined in another translation unit"); | |
61a74079 JH |
311 | if (cgraph_dump_file) |
312 | { | |
313 | fprintf (cgraph_dump_file, "ODR violation or merging or ODR type bug?\n"); | |
314 | ||
315 | print_node (cgraph_dump_file, "", val->type, 0); | |
316 | putc ('\n',cgraph_dump_file); | |
317 | print_node (cgraph_dump_file, "", type, 0); | |
318 | putc ('\n',cgraph_dump_file); | |
319 | } | |
320 | } | |
321 | ||
322 | /* Next sanity check that bases are the same. If not, we will end | |
323 | up producing wrong answers. */ | |
324 | for (j = 0, i = 0; i < BINFO_N_BASE_BINFOS (TYPE_BINFO (type)); i++) | |
325 | if (polymorphic_type_binfo_p (BINFO_BASE_BINFO (TYPE_BINFO (type), i))) | |
326 | { | |
327 | odr_type base = get_odr_type | |
328 | (BINFO_TYPE | |
329 | (BINFO_BASE_BINFO (TYPE_BINFO (type), | |
330 | i)), | |
331 | true); | |
332 | if (val->bases.length () <= j || val->bases[j] != base) | |
333 | base_mismatch = true; | |
334 | j++; | |
335 | } | |
336 | if (base_mismatch) | |
337 | { | |
338 | merge = false; | |
ec77d61f | 339 | odr_violation_reported = true; |
61a74079 JH |
340 | |
341 | if (warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (type)), 0, | |
342 | "type %qD violates one definition rule ", | |
343 | type)) | |
344 | inform (DECL_SOURCE_LOCATION (TYPE_NAME (val->type)), | |
345 | "a type with the same name but different bases is " | |
346 | "defined in another translation unit"); | |
347 | if (cgraph_dump_file) | |
348 | { | |
349 | fprintf (cgraph_dump_file, "ODR bse violation or merging bug?\n"); | |
350 | ||
351 | print_node (cgraph_dump_file, "", val->type, 0); | |
352 | putc ('\n',cgraph_dump_file); | |
353 | print_node (cgraph_dump_file, "", type, 0); | |
354 | putc ('\n',cgraph_dump_file); | |
355 | } | |
356 | } | |
357 | ||
358 | /* Regularize things a little. During LTO same types may come with | |
359 | different BINFOs. Either because their virtual table was | |
360 | not merged by tree merging and only later at decl merging or | |
361 | because one type comes with external vtable, while other | |
362 | with internal. We want to merge equivalent binfos to conserve | |
363 | memory and streaming overhead. | |
364 | ||
365 | The external vtables are more harmful: they contain references | |
366 | to external declarations of methods that may be defined in the | |
367 | merged LTO unit. For this reason we absolutely need to remove | |
368 | them and replace by internal variants. Not doing so will lead | |
369 | to incomplete answers from possible_polymorphic_call_targets. */ | |
370 | if (!flag_ltrans && merge) | |
371 | { | |
372 | tree master_binfo = TYPE_BINFO (val->type); | |
373 | tree v1 = BINFO_VTABLE (master_binfo); | |
374 | tree v2 = BINFO_VTABLE (TYPE_BINFO (type)); | |
375 | ||
376 | if (TREE_CODE (v1) == POINTER_PLUS_EXPR) | |
377 | { | |
378 | gcc_assert (TREE_CODE (v2) == POINTER_PLUS_EXPR | |
379 | && operand_equal_p (TREE_OPERAND (v1, 1), | |
380 | TREE_OPERAND (v2, 1), 0)); | |
381 | v1 = TREE_OPERAND (TREE_OPERAND (v1, 0), 0); | |
382 | v2 = TREE_OPERAND (TREE_OPERAND (v2, 0), 0); | |
383 | } | |
384 | gcc_assert (DECL_ASSEMBLER_NAME (v1) | |
385 | == DECL_ASSEMBLER_NAME (v2)); | |
386 | ||
387 | if (DECL_EXTERNAL (v1) && !DECL_EXTERNAL (v2)) | |
388 | { | |
389 | unsigned int i; | |
390 | ||
391 | TYPE_BINFO (val->type) = TYPE_BINFO (type); | |
c3284718 | 392 | for (i = 0; i < val->types->length (); i++) |
61a74079 JH |
393 | { |
394 | if (TYPE_BINFO ((*val->types)[i]) | |
395 | == master_binfo) | |
396 | TYPE_BINFO ((*val->types)[i]) = TYPE_BINFO (type); | |
397 | } | |
398 | } | |
399 | else | |
400 | TYPE_BINFO (type) = master_binfo; | |
401 | } | |
402 | } | |
403 | } | |
404 | ||
eefe9a99 JH |
405 | /* Get ODR type hash entry for TYPE. If INSERT is true, create |
406 | possibly new entry. */ | |
407 | ||
408 | odr_type | |
409 | get_odr_type (tree type, bool insert) | |
410 | { | |
411 | odr_type_d **slot; | |
412 | odr_type val; | |
413 | hashval_t hash; | |
414 | ||
415 | type = TYPE_MAIN_VARIANT (type); | |
416 | gcc_checking_assert (TYPE_MAIN_VARIANT (type) == type); | |
417 | hash = hash_type_name (type); | |
418 | slot = odr_hash.find_slot_with_hash (type, hash, insert ? INSERT : NO_INSERT); | |
419 | if (!slot) | |
420 | return NULL; | |
421 | ||
422 | /* See if we already have entry for type. */ | |
423 | if (*slot) | |
424 | { | |
425 | val = *slot; | |
426 | ||
61a74079 JH |
427 | /* With LTO we need to support multiple tree representation of |
428 | the same ODR type. */ | |
429 | if (val->type != type) | |
430 | add_type_duplicate (val, type); | |
eefe9a99 JH |
431 | } |
432 | else | |
433 | { | |
434 | tree binfo = TYPE_BINFO (type); | |
435 | unsigned int i; | |
436 | ||
437 | val = ggc_alloc_cleared_odr_type_d (); | |
438 | val->type = type; | |
439 | val->bases = vNULL; | |
440 | val->derived_types = vNULL; | |
0e1474e5 | 441 | val->anonymous_namespace = type_in_anonymous_namespace_p (type); |
eefe9a99 JH |
442 | *slot = val; |
443 | for (i = 0; i < BINFO_N_BASE_BINFOS (binfo); i++) | |
444 | /* For now record only polymorphic types. other are | |
445 | pointless for devirtualization and we can not precisely | |
446 | determine ODR equivalency of these during LTO. */ | |
447 | if (polymorphic_type_binfo_p (BINFO_BASE_BINFO (binfo, i))) | |
448 | { | |
449 | odr_type base = get_odr_type (BINFO_TYPE (BINFO_BASE_BINFO (binfo, | |
450 | i)), | |
451 | true); | |
452 | base->derived_types.safe_push (val); | |
453 | val->bases.safe_push (base); | |
454 | } | |
455 | /* First record bases, then add into array so ids are increasing. */ | |
456 | if (odr_types_ptr) | |
c3284718 | 457 | val->id = odr_types.length (); |
eefe9a99 JH |
458 | vec_safe_push (odr_types_ptr, val); |
459 | } | |
460 | return val; | |
461 | } | |
462 | ||
463 | /* Dump ODR type T and all its derrived type. INDENT specify indentation for | |
464 | recusive printing. */ | |
465 | ||
466 | static void | |
467 | dump_odr_type (FILE *f, odr_type t, int indent=0) | |
468 | { | |
469 | unsigned int i; | |
470 | fprintf (f, "%*s type %i: ", indent * 2, "", t->id); | |
471 | print_generic_expr (f, t->type, TDF_SLIM); | |
0e1474e5 | 472 | fprintf (f, "%s\n", t->anonymous_namespace ? " (anonymous namespace)":""); |
eefe9a99 JH |
473 | if (TYPE_NAME (t->type)) |
474 | { | |
475 | fprintf (f, "%*s defined at: %s:%i\n", indent * 2, "", | |
476 | DECL_SOURCE_FILE (TYPE_NAME (t->type)), | |
477 | DECL_SOURCE_LINE (TYPE_NAME (t->type))); | |
478 | } | |
c3284718 | 479 | if (t->bases.length ()) |
eefe9a99 JH |
480 | { |
481 | fprintf (f, "%*s base odr type ids: ", indent * 2, ""); | |
c3284718 | 482 | for (i = 0; i < t->bases.length (); i++) |
eefe9a99 JH |
483 | fprintf (f, " %i", t->bases[i]->id); |
484 | fprintf (f, "\n"); | |
485 | } | |
c3284718 | 486 | if (t->derived_types.length ()) |
eefe9a99 JH |
487 | { |
488 | fprintf (f, "%*s derived types:\n", indent * 2, ""); | |
c3284718 | 489 | for (i = 0; i < t->derived_types.length (); i++) |
eefe9a99 JH |
490 | dump_odr_type (f, t->derived_types[i], indent + 1); |
491 | } | |
492 | fprintf (f, "\n"); | |
493 | } | |
494 | ||
495 | /* Dump the type inheritance graph. */ | |
496 | ||
497 | static void | |
498 | dump_type_inheritance_graph (FILE *f) | |
499 | { | |
500 | unsigned int i; | |
0e1474e5 JH |
501 | if (!odr_types_ptr) |
502 | return; | |
eefe9a99 | 503 | fprintf (f, "\n\nType inheritance graph:\n"); |
c3284718 | 504 | for (i = 0; i < odr_types.length (); i++) |
eefe9a99 | 505 | { |
c3284718 | 506 | if (odr_types[i]->bases.length () == 0) |
eefe9a99 JH |
507 | dump_odr_type (f, odr_types[i]); |
508 | } | |
c3284718 | 509 | for (i = 0; i < odr_types.length (); i++) |
61a74079 | 510 | { |
c3284718 | 511 | if (odr_types[i]->types && odr_types[i]->types->length ()) |
61a74079 JH |
512 | { |
513 | unsigned int j; | |
514 | fprintf (f, "Duplicate tree types for odr type %i\n", i); | |
515 | print_node (f, "", odr_types[i]->type, 0); | |
c3284718 | 516 | for (j = 0; j < odr_types[i]->types->length (); j++) |
61a74079 JH |
517 | { |
518 | tree t; | |
519 | fprintf (f, "duplicate #%i\n", j); | |
520 | print_node (f, "", (*odr_types[i]->types)[j], 0); | |
521 | t = (*odr_types[i]->types)[j]; | |
522 | while (TYPE_P (t) && TYPE_CONTEXT (t)) | |
523 | { | |
524 | t = TYPE_CONTEXT (t); | |
525 | print_node (f, "", t, 0); | |
526 | } | |
527 | putc ('\n',f); | |
528 | } | |
529 | } | |
530 | } | |
eefe9a99 JH |
531 | } |
532 | ||
533 | /* Given method type T, return type of class it belongs to. | |
534 | Lookup this pointer and get its type. */ | |
535 | ||
64cbf23d | 536 | tree |
eefe9a99 JH |
537 | method_class_type (tree t) |
538 | { | |
539 | tree first_parm_type = TREE_VALUE (TYPE_ARG_TYPES (t)); | |
68377e53 | 540 | gcc_assert (TREE_CODE (t) == METHOD_TYPE); |
eefe9a99 JH |
541 | |
542 | return TREE_TYPE (first_parm_type); | |
543 | } | |
544 | ||
545 | /* Initialize IPA devirt and build inheritance tree graph. */ | |
546 | ||
547 | void | |
548 | build_type_inheritance_graph (void) | |
549 | { | |
b270b096 | 550 | struct symtab_node *n; |
eefe9a99 JH |
551 | FILE *inheritance_dump_file; |
552 | int flags; | |
553 | ||
554 | if (odr_hash.is_created ()) | |
555 | return; | |
556 | timevar_push (TV_IPA_INHERITANCE); | |
557 | inheritance_dump_file = dump_begin (TDI_inheritance, &flags); | |
558 | odr_hash.create (23); | |
559 | ||
560 | /* We reconstruct the graph starting of types of all methods seen in the | |
561 | the unit. */ | |
b270b096 JH |
562 | FOR_EACH_SYMBOL (n) |
563 | if (is_a <cgraph_node> (n) | |
564 | && DECL_VIRTUAL_P (n->decl) | |
67348ccc DM |
565 | && symtab_real_symbol_p (n)) |
566 | get_odr_type (method_class_type (TREE_TYPE (n->decl)), true); | |
b270b096 JH |
567 | |
568 | /* Look also for virtual tables of types that do not define any methods. | |
569 | ||
570 | We need it in a case where class B has virtual base of class A | |
571 | re-defining its virtual method and there is class C with no virtual | |
572 | methods with B as virtual base. | |
573 | ||
574 | Here we output B's virtual method in two variant - for non-virtual | |
575 | and virtual inheritance. B's virtual table has non-virtual version, | |
576 | while C's has virtual. | |
577 | ||
578 | For this reason we need to know about C in order to include both | |
579 | variants of B. More correctly, record_target_from_binfo should | |
580 | add both variants of the method when walking B, but we have no | |
581 | link in between them. | |
582 | ||
583 | We rely on fact that either the method is exported and thus we | |
584 | assume it is called externally or C is in anonymous namespace and | |
585 | thus we will see the vtable. */ | |
586 | ||
587 | else if (is_a <varpool_node> (n) | |
588 | && DECL_VIRTUAL_P (n->decl) | |
589 | && TREE_CODE (DECL_CONTEXT (n->decl)) == RECORD_TYPE | |
590 | && TYPE_BINFO (DECL_CONTEXT (n->decl)) | |
591 | && polymorphic_type_binfo_p (TYPE_BINFO (DECL_CONTEXT (n->decl)))) | |
592 | get_odr_type (DECL_CONTEXT (n->decl), true); | |
eefe9a99 JH |
593 | if (inheritance_dump_file) |
594 | { | |
595 | dump_type_inheritance_graph (inheritance_dump_file); | |
596 | dump_end (TDI_inheritance, inheritance_dump_file); | |
597 | } | |
598 | timevar_pop (TV_IPA_INHERITANCE); | |
599 | } | |
600 | ||
68377e53 | 601 | /* If TARGET has associated node, record it in the NODES array. |
ec77d61f JH |
602 | CAN_REFER specify if program can refer to the target directly. |
603 | if TARGET is unknown (NULL) or it can not be inserted (for example because | |
604 | its body was already removed and there is no way to refer to it), clear | |
605 | COMPLETEP. */ | |
eefe9a99 JH |
606 | |
607 | static void | |
608 | maybe_record_node (vec <cgraph_node *> &nodes, | |
68377e53 | 609 | tree target, pointer_set_t *inserted, |
ec77d61f | 610 | bool can_refer, |
68377e53 | 611 | bool *completep) |
eefe9a99 JH |
612 | { |
613 | struct cgraph_node *target_node; | |
614 | enum built_in_function fcode; | |
615 | ||
ec77d61f JH |
616 | if (!can_refer) |
617 | { | |
618 | /* The only case when method of anonymous namespace becomes unreferable | |
619 | is when we completely optimized it out. */ | |
620 | if (flag_ltrans | |
621 | || !target | |
622 | || !type_in_anonymous_namespace_p (DECL_CONTEXT (target))) | |
623 | *completep = false; | |
624 | return; | |
625 | } | |
626 | ||
68377e53 | 627 | if (!target |
eefe9a99 | 628 | /* Those are used to mark impossible scenarios. */ |
68377e53 JH |
629 | || (fcode = DECL_FUNCTION_CODE (target)) |
630 | == BUILT_IN_UNREACHABLE | |
631 | || fcode == BUILT_IN_TRAP) | |
632 | return; | |
633 | ||
634 | target_node = cgraph_get_node (target); | |
635 | ||
636 | if (target_node != NULL | |
3462aa02 | 637 | && (TREE_PUBLIC (target) |
67348ccc DM |
638 | || target_node->definition) |
639 | && symtab_real_symbol_p (target_node)) | |
0e1474e5 | 640 | { |
68377e53 JH |
641 | gcc_assert (!target_node->global.inlined_to); |
642 | gcc_assert (symtab_real_symbol_p (target_node)); | |
643 | if (!pointer_set_insert (inserted, target)) | |
644 | { | |
645 | pointer_set_insert (cached_polymorphic_call_targets, | |
646 | target_node); | |
647 | nodes.safe_push (target_node); | |
648 | } | |
0e1474e5 | 649 | } |
68377e53 JH |
650 | else if (completep |
651 | && !type_in_anonymous_namespace_p | |
652 | (method_class_type (TREE_TYPE (target)))) | |
653 | *completep = true; | |
eefe9a99 JH |
654 | } |
655 | ||
68377e53 JH |
656 | /* See if BINFO's type match OUTER_TYPE. If so, lookup |
657 | BINFO of subtype of OTR_TYPE at OFFSET and in that BINFO find | |
658 | method in vtable and insert method to NODES array. | |
eefe9a99 JH |
659 | Otherwise recurse to base BINFOs. |
660 | This match what get_binfo_at_offset does, but with offset | |
661 | being unknown. | |
662 | ||
a3788dde JH |
663 | TYPE_BINFOS is a stack of BINFOS of types with defined |
664 | virtual table seen on way from class type to BINFO. | |
eefe9a99 JH |
665 | |
666 | MATCHED_VTABLES tracks virtual tables we already did lookup | |
68377e53 JH |
667 | for virtual function in. INSERTED tracks nodes we already |
668 | inserted. | |
3462aa02 JH |
669 | |
670 | ANONYMOUS is true if BINFO is part of anonymous namespace. | |
ec77d61f JH |
671 | |
672 | Clear COMPLETEP when we hit unreferable target. | |
eefe9a99 JH |
673 | */ |
674 | ||
675 | static void | |
68377e53 JH |
676 | record_target_from_binfo (vec <cgraph_node *> &nodes, |
677 | tree binfo, | |
678 | tree otr_type, | |
a3788dde | 679 | vec <tree> &type_binfos, |
68377e53 JH |
680 | HOST_WIDE_INT otr_token, |
681 | tree outer_type, | |
682 | HOST_WIDE_INT offset, | |
683 | pointer_set_t *inserted, | |
684 | pointer_set_t *matched_vtables, | |
ec77d61f JH |
685 | bool anonymous, |
686 | bool *completep) | |
eefe9a99 JH |
687 | { |
688 | tree type = BINFO_TYPE (binfo); | |
689 | int i; | |
690 | tree base_binfo; | |
691 | ||
eefe9a99 | 692 | |
a3788dde JH |
693 | if (BINFO_VTABLE (binfo)) |
694 | type_binfos.safe_push (binfo); | |
68377e53 | 695 | if (types_same_for_odr (type, outer_type)) |
eefe9a99 | 696 | { |
a3788dde JH |
697 | int i; |
698 | tree type_binfo = NULL; | |
699 | ||
700 | /* Lookup BINFO with virtual table. For normal types it is always last | |
701 | binfo on stack. */ | |
702 | for (i = type_binfos.length () - 1; i >= 0; i--) | |
703 | if (BINFO_OFFSET (type_binfos[i]) == BINFO_OFFSET (binfo)) | |
704 | { | |
705 | type_binfo = type_binfos[i]; | |
706 | break; | |
707 | } | |
708 | if (BINFO_VTABLE (binfo)) | |
709 | type_binfos.pop (); | |
710 | /* If this is duplicated BINFO for base shared by virtual inheritance, | |
711 | we may not have its associated vtable. This is not a problem, since | |
712 | we will walk it on the other path. */ | |
713 | if (!type_binfo) | |
6d6af792 | 714 | return; |
68377e53 JH |
715 | tree inner_binfo = get_binfo_at_offset (type_binfo, |
716 | offset, otr_type); | |
ec77d61f JH |
717 | if (!inner_binfo) |
718 | { | |
719 | gcc_assert (odr_violation_reported); | |
720 | return; | |
721 | } | |
3462aa02 JH |
722 | /* For types in anonymous namespace first check if the respective vtable |
723 | is alive. If not, we know the type can't be called. */ | |
724 | if (!flag_ltrans && anonymous) | |
725 | { | |
68377e53 | 726 | tree vtable = BINFO_VTABLE (inner_binfo); |
2c8326a5 | 727 | varpool_node *vnode; |
3462aa02 JH |
728 | |
729 | if (TREE_CODE (vtable) == POINTER_PLUS_EXPR) | |
730 | vtable = TREE_OPERAND (TREE_OPERAND (vtable, 0), 0); | |
731 | vnode = varpool_get_node (vtable); | |
67348ccc | 732 | if (!vnode || !vnode->definition) |
3462aa02 JH |
733 | return; |
734 | } | |
68377e53 JH |
735 | gcc_assert (inner_binfo); |
736 | if (!pointer_set_insert (matched_vtables, BINFO_VTABLE (inner_binfo))) | |
737 | { | |
ec77d61f JH |
738 | bool can_refer; |
739 | tree target = gimple_get_virt_method_for_binfo (otr_token, | |
740 | inner_binfo, | |
741 | &can_refer); | |
742 | maybe_record_node (nodes, target, inserted, can_refer, completep); | |
68377e53 | 743 | } |
eefe9a99 JH |
744 | return; |
745 | } | |
746 | ||
747 | /* Walk bases. */ | |
748 | for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) | |
749 | /* Walking bases that have no virtual method is pointless excercise. */ | |
750 | if (polymorphic_type_binfo_p (base_binfo)) | |
68377e53 | 751 | record_target_from_binfo (nodes, base_binfo, otr_type, |
a3788dde | 752 | type_binfos, |
68377e53 | 753 | otr_token, outer_type, offset, inserted, |
ec77d61f | 754 | matched_vtables, anonymous, completep); |
a3788dde JH |
755 | if (BINFO_VTABLE (binfo)) |
756 | type_binfos.pop (); | |
eefe9a99 JH |
757 | } |
758 | ||
759 | /* Lookup virtual methods matching OTR_TYPE (with OFFSET and OTR_TOKEN) | |
760 | of TYPE, insert them to NODES, recurse into derived nodes. | |
761 | INSERTED is used to avoid duplicate insertions of methods into NODES. | |
ec77d61f JH |
762 | MATCHED_VTABLES are used to avoid duplicate walking vtables. |
763 | Clear COMPLETEP if unreferable target is found. */ | |
eefe9a99 JH |
764 | |
765 | static void | |
766 | possible_polymorphic_call_targets_1 (vec <cgraph_node *> &nodes, | |
767 | pointer_set_t *inserted, | |
768 | pointer_set_t *matched_vtables, | |
769 | tree otr_type, | |
770 | odr_type type, | |
68377e53 JH |
771 | HOST_WIDE_INT otr_token, |
772 | tree outer_type, | |
ec77d61f JH |
773 | HOST_WIDE_INT offset, |
774 | bool *completep) | |
eefe9a99 JH |
775 | { |
776 | tree binfo = TYPE_BINFO (type->type); | |
777 | unsigned int i; | |
a3788dde | 778 | vec <tree> type_binfos = vNULL; |
eefe9a99 | 779 | |
a3788dde | 780 | record_target_from_binfo (nodes, binfo, otr_type, type_binfos, otr_token, |
68377e53 JH |
781 | outer_type, offset, |
782 | inserted, matched_vtables, | |
ec77d61f | 783 | type->anonymous_namespace, completep); |
a3788dde | 784 | type_binfos.release (); |
c3284718 | 785 | for (i = 0; i < type->derived_types.length (); i++) |
eefe9a99 JH |
786 | possible_polymorphic_call_targets_1 (nodes, inserted, |
787 | matched_vtables, | |
788 | otr_type, | |
789 | type->derived_types[i], | |
ec77d61f | 790 | otr_token, outer_type, offset, completep); |
eefe9a99 JH |
791 | } |
792 | ||
793 | /* Cache of queries for polymorphic call targets. | |
794 | ||
795 | Enumerating all call targets may get expensive when there are many | |
796 | polymorphic calls in the program, so we memoize all the previous | |
797 | queries and avoid duplicated work. */ | |
798 | ||
799 | struct polymorphic_call_target_d | |
800 | { | |
eefe9a99 | 801 | HOST_WIDE_INT otr_token; |
68377e53 JH |
802 | ipa_polymorphic_call_context context; |
803 | odr_type type; | |
eefe9a99 | 804 | vec <cgraph_node *> targets; |
ec77d61f JH |
805 | int nonconstruction_targets; |
806 | bool complete; | |
eefe9a99 JH |
807 | }; |
808 | ||
809 | /* Polymorphic call target cache helpers. */ | |
810 | ||
811 | struct polymorphic_call_target_hasher | |
812 | { | |
813 | typedef polymorphic_call_target_d value_type; | |
814 | typedef polymorphic_call_target_d compare_type; | |
815 | static inline hashval_t hash (const value_type *); | |
816 | static inline bool equal (const value_type *, const compare_type *); | |
817 | static inline void remove (value_type *); | |
818 | }; | |
819 | ||
820 | /* Return the computed hashcode for ODR_QUERY. */ | |
821 | ||
822 | inline hashval_t | |
823 | polymorphic_call_target_hasher::hash (const value_type *odr_query) | |
824 | { | |
68377e53 JH |
825 | hashval_t hash; |
826 | ||
827 | hash = iterative_hash_host_wide_int | |
828 | (odr_query->otr_token, | |
829 | odr_query->type->id); | |
830 | hash = iterative_hash_hashval_t (TYPE_UID (odr_query->context.outer_type), | |
831 | hash); | |
832 | hash = iterative_hash_host_wide_int (odr_query->context.offset, hash); | |
833 | return iterative_hash_hashval_t | |
834 | (((int)odr_query->context.maybe_in_construction << 1) | |
835 | | (int)odr_query->context.maybe_derived_type, hash); | |
eefe9a99 JH |
836 | } |
837 | ||
838 | /* Compare cache entries T1 and T2. */ | |
839 | ||
840 | inline bool | |
841 | polymorphic_call_target_hasher::equal (const value_type *t1, | |
842 | const compare_type *t2) | |
843 | { | |
68377e53 JH |
844 | return (t1->type == t2->type && t1->otr_token == t2->otr_token |
845 | && t1->context.offset == t2->context.offset | |
846 | && t1->context.outer_type == t2->context.outer_type | |
847 | && t1->context.maybe_in_construction | |
848 | == t2->context.maybe_in_construction | |
849 | && t1->context.maybe_derived_type == t2->context.maybe_derived_type); | |
eefe9a99 JH |
850 | } |
851 | ||
852 | /* Remove entry in polymorphic call target cache hash. */ | |
853 | ||
854 | inline void | |
855 | polymorphic_call_target_hasher::remove (value_type *v) | |
856 | { | |
857 | v->targets.release (); | |
858 | free (v); | |
859 | } | |
860 | ||
861 | /* Polymorphic call target query cache. */ | |
862 | ||
863 | typedef hash_table <polymorphic_call_target_hasher> | |
864 | polymorphic_call_target_hash_type; | |
865 | static polymorphic_call_target_hash_type polymorphic_call_target_hash; | |
eefe9a99 JH |
866 | |
867 | /* Destroy polymorphic call target query cache. */ | |
868 | ||
869 | static void | |
870 | free_polymorphic_call_targets_hash () | |
871 | { | |
0e1474e5 JH |
872 | if (cached_polymorphic_call_targets) |
873 | { | |
874 | polymorphic_call_target_hash.dispose (); | |
875 | pointer_set_destroy (cached_polymorphic_call_targets); | |
876 | cached_polymorphic_call_targets = NULL; | |
877 | } | |
eefe9a99 JH |
878 | } |
879 | ||
880 | /* When virtual function is removed, we may need to flush the cache. */ | |
881 | ||
882 | static void | |
883 | devirt_node_removal_hook (struct cgraph_node *n, void *d ATTRIBUTE_UNUSED) | |
884 | { | |
0e1474e5 JH |
885 | if (cached_polymorphic_call_targets |
886 | && pointer_set_contains (cached_polymorphic_call_targets, n)) | |
eefe9a99 JH |
887 | free_polymorphic_call_targets_hash (); |
888 | } | |
889 | ||
68377e53 JH |
890 | /* CONTEXT->OUTER_TYPE is a type of memory object where object of EXPECTED_TYPE |
891 | is contained at CONTEXT->OFFSET. Walk the memory representation of | |
892 | CONTEXT->OUTER_TYPE and find the outermost class type that match | |
893 | EXPECTED_TYPE or contain EXPECTED_TYPE as a base. Update CONTEXT | |
894 | to represent it. | |
895 | ||
896 | For example when CONTEXT represents type | |
897 | class A | |
898 | { | |
899 | int a; | |
900 | class B b; | |
901 | } | |
902 | and we look for type at offset sizeof(int), we end up with B and offset 0. | |
903 | If the same is produced by multiple inheritance, we end up with A and offset | |
904 | sizeof(int). | |
905 | ||
906 | If we can not find corresponding class, give up by setting | |
907 | CONTEXT->OUTER_TYPE to EXPECTED_TYPE and CONTEXT->OFFSET to NULL. | |
908 | Return true when lookup was sucesful. */ | |
909 | ||
910 | static bool | |
911 | get_class_context (ipa_polymorphic_call_context *context, | |
912 | tree expected_type) | |
913 | { | |
914 | tree type = context->outer_type; | |
915 | HOST_WIDE_INT offset = context->offset; | |
916 | ||
917 | /* Find the sub-object the constant actually refers to and mark whether it is | |
918 | an artificial one (as opposed to a user-defined one). */ | |
919 | while (true) | |
920 | { | |
921 | HOST_WIDE_INT pos, size; | |
922 | tree fld; | |
923 | ||
924 | /* On a match, just return what we found. */ | |
925 | if (TREE_CODE (type) == TREE_CODE (expected_type) | |
926 | && types_same_for_odr (type, expected_type)) | |
927 | { | |
3b4e93c3 JH |
928 | /* Type can not contain itself on an non-zero offset. In that case |
929 | just give up. */ | |
930 | if (offset != 0) | |
931 | goto give_up; | |
68377e53 JH |
932 | gcc_assert (offset == 0); |
933 | return true; | |
934 | } | |
935 | ||
936 | /* Walk fields and find corresponding on at OFFSET. */ | |
937 | if (TREE_CODE (type) == RECORD_TYPE) | |
938 | { | |
939 | for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) | |
940 | { | |
941 | if (TREE_CODE (fld) != FIELD_DECL) | |
942 | continue; | |
943 | ||
944 | pos = int_bit_position (fld); | |
945 | size = tree_to_uhwi (DECL_SIZE (fld)); | |
946 | if (pos <= offset && (pos + size) > offset) | |
947 | break; | |
948 | } | |
949 | ||
950 | if (!fld) | |
951 | goto give_up; | |
952 | ||
953 | type = TREE_TYPE (fld); | |
954 | offset -= pos; | |
955 | /* DECL_ARTIFICIAL represents a basetype. */ | |
956 | if (!DECL_ARTIFICIAL (fld)) | |
957 | { | |
958 | context->outer_type = type; | |
959 | context->offset = offset; | |
960 | /* As soon as we se an field containing the type, | |
961 | we know we are not looking for derivations. */ | |
962 | context->maybe_derived_type = false; | |
963 | } | |
964 | } | |
965 | else if (TREE_CODE (type) == ARRAY_TYPE) | |
966 | { | |
967 | tree subtype = TREE_TYPE (type); | |
968 | ||
969 | /* Give up if we don't know array size. */ | |
970 | if (!tree_fits_shwi_p (TYPE_SIZE (subtype)) | |
971 | || !tree_to_shwi (TYPE_SIZE (subtype)) <= 0) | |
972 | goto give_up; | |
973 | offset = offset % tree_to_shwi (TYPE_SIZE (subtype)); | |
974 | type = subtype; | |
975 | context->outer_type = type; | |
976 | context->offset = offset; | |
977 | context->maybe_derived_type = false; | |
978 | } | |
979 | /* Give up on anything else. */ | |
980 | else | |
981 | goto give_up; | |
982 | } | |
983 | ||
984 | /* If we failed to find subtype we look for, give up and fall back to the | |
985 | most generic query. */ | |
986 | give_up: | |
987 | context->outer_type = expected_type; | |
988 | context->offset = 0; | |
989 | context->maybe_derived_type = true; | |
990 | return false; | |
991 | } | |
992 | ||
993 | /* Return true if OUTER_TYPE contains OTR_TYPE at OFFSET. */ | |
994 | ||
995 | static bool | |
996 | contains_type_p (tree outer_type, HOST_WIDE_INT offset, | |
997 | tree otr_type) | |
998 | { | |
999 | ipa_polymorphic_call_context context = {offset, outer_type, | |
1000 | false, true}; | |
1001 | return get_class_context (&context, otr_type); | |
1002 | } | |
1003 | ||
390675c8 JH |
1004 | /* Lookup base of BINFO that has virtual table VTABLE with OFFSET. */ |
1005 | ||
1006 | static tree | |
85942f45 JH |
1007 | subbinfo_with_vtable_at_offset (tree binfo, unsigned HOST_WIDE_INT offset, |
1008 | tree vtable) | |
390675c8 JH |
1009 | { |
1010 | tree v = BINFO_VTABLE (binfo); | |
1011 | int i; | |
1012 | tree base_binfo; | |
85942f45 | 1013 | unsigned HOST_WIDE_INT this_offset; |
390675c8 | 1014 | |
85942f45 JH |
1015 | if (v) |
1016 | { | |
1017 | if (!vtable_pointer_value_to_vtable (v, &v, &this_offset)) | |
1018 | gcc_unreachable (); | |
1019 | ||
1020 | if (offset == this_offset | |
1021 | && DECL_ASSEMBLER_NAME (v) == DECL_ASSEMBLER_NAME (vtable)) | |
1022 | return binfo; | |
1023 | } | |
390675c8 | 1024 | |
390675c8 JH |
1025 | for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) |
1026 | if (polymorphic_type_binfo_p (base_binfo)) | |
1027 | { | |
1028 | base_binfo = subbinfo_with_vtable_at_offset (base_binfo, offset, vtable); | |
1029 | if (base_binfo) | |
1030 | return base_binfo; | |
1031 | } | |
1032 | return NULL; | |
1033 | } | |
1034 | ||
85942f45 JH |
1035 | /* T is known constant value of virtual table pointer. |
1036 | Store virtual table to V and its offset to OFFSET. | |
1037 | Return false if T does not look like virtual table reference. */ | |
390675c8 | 1038 | |
85942f45 JH |
1039 | bool |
1040 | vtable_pointer_value_to_vtable (tree t, tree *v, unsigned HOST_WIDE_INT *offset) | |
390675c8 JH |
1041 | { |
1042 | /* We expect &MEM[(void *)&virtual_table + 16B]. | |
1043 | We obtain object's BINFO from the context of the virtual table. | |
1044 | This one contains pointer to virtual table represented via | |
1045 | POINTER_PLUS_EXPR. Verify that this pointer match to what | |
1046 | we propagated through. | |
1047 | ||
1048 | In the case of virtual inheritance, the virtual tables may | |
1049 | be nested, i.e. the offset may be different from 16 and we may | |
1050 | need to dive into the type representation. */ | |
85942f45 | 1051 | if (TREE_CODE (t) == ADDR_EXPR |
390675c8 JH |
1052 | && TREE_CODE (TREE_OPERAND (t, 0)) == MEM_REF |
1053 | && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == ADDR_EXPR | |
1054 | && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST | |
1055 | && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 0)) | |
1056 | == VAR_DECL) | |
1057 | && DECL_VIRTUAL_P (TREE_OPERAND (TREE_OPERAND | |
1058 | (TREE_OPERAND (t, 0), 0), 0))) | |
1059 | { | |
85942f45 JH |
1060 | *v = TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 0); |
1061 | *offset = tree_to_uhwi (TREE_OPERAND (TREE_OPERAND (t, 0), 1)); | |
1062 | return true; | |
390675c8 | 1063 | } |
85942f45 JH |
1064 | |
1065 | /* Alternative representation, used by C++ frontend is POINTER_PLUS_EXPR. | |
1066 | We need to handle it when T comes from static variable initializer or | |
1067 | BINFO. */ | |
1068 | if (TREE_CODE (t) == POINTER_PLUS_EXPR) | |
1069 | { | |
1070 | *offset = tree_to_uhwi (TREE_OPERAND (t, 1)); | |
1071 | t = TREE_OPERAND (t, 0); | |
1072 | } | |
1073 | else | |
1074 | *offset = 0; | |
1075 | ||
1076 | if (TREE_CODE (t) != ADDR_EXPR) | |
1077 | return false; | |
1078 | *v = TREE_OPERAND (t, 0); | |
1079 | return true; | |
1080 | } | |
1081 | ||
1082 | /* T is known constant value of virtual table pointer. Return BINFO of the | |
1083 | instance type. */ | |
1084 | ||
1085 | tree | |
1086 | vtable_pointer_value_to_binfo (tree t) | |
1087 | { | |
1088 | tree vtable; | |
1089 | unsigned HOST_WIDE_INT offset; | |
1090 | ||
1091 | if (!vtable_pointer_value_to_vtable (t, &vtable, &offset)) | |
1092 | return NULL_TREE; | |
1093 | ||
1094 | /* FIXME: for stores of construction vtables we return NULL, | |
1095 | because we do not have BINFO for those. Eventually we should fix | |
1096 | our representation to allow this case to be handled, too. | |
1097 | In the case we see store of BINFO we however may assume | |
1098 | that standard folding will be ale to cope with it. */ | |
1099 | return subbinfo_with_vtable_at_offset (TYPE_BINFO (DECL_CONTEXT (vtable)), | |
1100 | offset, vtable); | |
390675c8 JH |
1101 | } |
1102 | ||
5bccb77a JH |
1103 | /* Proudce polymorphic call context for call method of instance |
1104 | that is located within BASE (that is assumed to be a decl) at OFFSET. */ | |
1105 | ||
1106 | static void | |
1107 | get_polymorphic_call_info_for_decl (ipa_polymorphic_call_context *context, | |
1108 | tree base, HOST_WIDE_INT offset) | |
1109 | { | |
1110 | gcc_assert (DECL_P (base)); | |
1111 | ||
1112 | context->outer_type = TREE_TYPE (base); | |
1113 | context->offset = offset; | |
1114 | /* Make very conservative assumption that all objects | |
1115 | may be in construction. | |
1116 | TODO: ipa-prop already contains code to tell better. | |
1117 | merge it later. */ | |
1118 | context->maybe_in_construction = true; | |
1119 | context->maybe_derived_type = false; | |
1120 | } | |
1121 | ||
1122 | /* CST is an invariant (address of decl), try to get meaningful | |
1123 | polymorphic call context for polymorphic call of method | |
1124 | if instance of OTR_TYPE that is located at OFFSET of this invariant. | |
1125 | Return FALSE if nothing meaningful can be found. */ | |
1126 | ||
1127 | bool | |
1128 | get_polymorphic_call_info_from_invariant (ipa_polymorphic_call_context *context, | |
1129 | tree cst, | |
1130 | tree otr_type, | |
1131 | HOST_WIDE_INT offset) | |
1132 | { | |
1133 | HOST_WIDE_INT offset2, size, max_size; | |
1134 | tree base; | |
1135 | ||
1136 | if (TREE_CODE (cst) != ADDR_EXPR) | |
79c7de84 | 1137 | return false; |
5bccb77a JH |
1138 | |
1139 | cst = TREE_OPERAND (cst, 0); | |
1140 | base = get_ref_base_and_extent (cst, &offset2, &size, &max_size); | |
79c7de84 EB |
1141 | if (!DECL_P (base) || max_size == -1 || max_size != size) |
1142 | return false; | |
5bccb77a JH |
1143 | |
1144 | /* Only type inconsistent programs can have otr_type that is | |
1145 | not part of outer type. */ | |
79c7de84 EB |
1146 | if (!contains_type_p (TREE_TYPE (base), offset, otr_type)) |
1147 | return false; | |
5bccb77a | 1148 | |
79c7de84 | 1149 | get_polymorphic_call_info_for_decl (context, base, offset); |
5bccb77a JH |
1150 | return true; |
1151 | } | |
1152 | ||
68377e53 JH |
1153 | /* Given REF call in FNDECL, determine class of the polymorphic |
1154 | call (OTR_TYPE), its token (OTR_TOKEN) and CONTEXT. | |
1155 | Return pointer to object described by the context */ | |
1156 | ||
1157 | tree | |
1158 | get_polymorphic_call_info (tree fndecl, | |
1159 | tree ref, | |
1160 | tree *otr_type, | |
1161 | HOST_WIDE_INT *otr_token, | |
1162 | ipa_polymorphic_call_context *context) | |
1163 | { | |
1164 | tree base_pointer; | |
1165 | *otr_type = obj_type_ref_class (ref); | |
1166 | *otr_token = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (ref)); | |
1167 | ||
1168 | /* Set up basic info in case we find nothing interesting in the analysis. */ | |
1169 | context->outer_type = *otr_type; | |
1170 | context->offset = 0; | |
1171 | base_pointer = OBJ_TYPE_REF_OBJECT (ref); | |
1172 | context->maybe_derived_type = true; | |
1173 | context->maybe_in_construction = false; | |
1174 | ||
1175 | /* Walk SSA for outer object. */ | |
1176 | do | |
1177 | { | |
1178 | if (TREE_CODE (base_pointer) == SSA_NAME | |
1179 | && !SSA_NAME_IS_DEFAULT_DEF (base_pointer) | |
1180 | && SSA_NAME_DEF_STMT (base_pointer) | |
1181 | && gimple_assign_single_p (SSA_NAME_DEF_STMT (base_pointer))) | |
1182 | { | |
1183 | base_pointer = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (base_pointer)); | |
1184 | STRIP_NOPS (base_pointer); | |
1185 | } | |
1186 | else if (TREE_CODE (base_pointer) == ADDR_EXPR) | |
1187 | { | |
1188 | HOST_WIDE_INT size, max_size; | |
1189 | HOST_WIDE_INT offset2; | |
1190 | tree base = get_ref_base_and_extent (TREE_OPERAND (base_pointer, 0), | |
1191 | &offset2, &size, &max_size); | |
1192 | ||
1193 | /* If this is a varying address, punt. */ | |
1194 | if ((TREE_CODE (base) == MEM_REF || DECL_P (base)) | |
1195 | && max_size != -1 | |
1196 | && max_size == size) | |
1197 | { | |
1198 | /* We found dereference of a pointer. Type of the pointer | |
1199 | and MEM_REF is meaningless, but we can look futher. */ | |
1200 | if (TREE_CODE (base) == MEM_REF) | |
1201 | { | |
1202 | base_pointer = TREE_OPERAND (base, 0); | |
1203 | context->offset | |
1204 | += offset2 + mem_ref_offset (base).low * BITS_PER_UNIT; | |
1205 | context->outer_type = NULL; | |
1206 | } | |
1207 | /* We found base object. In this case the outer_type | |
1208 | is known. */ | |
1209 | else if (DECL_P (base)) | |
1210 | { | |
7656ee72 | 1211 | gcc_assert (!POINTER_TYPE_P (TREE_TYPE (base))); |
68377e53 JH |
1212 | |
1213 | /* Only type inconsistent programs can have otr_type that is | |
1214 | not part of outer type. */ | |
7656ee72 JH |
1215 | if (!contains_type_p (TREE_TYPE (base), |
1216 | context->offset + offset2, *otr_type)) | |
3e86c6a8 JH |
1217 | { |
1218 | /* Use OTR_TOKEN = INT_MAX as a marker of probably type inconsistent | |
1219 | code sequences; we arrange the calls to be builtin_unreachable | |
1220 | later. */ | |
1221 | *otr_token = INT_MAX; | |
1222 | return base_pointer; | |
1223 | } | |
5bccb77a JH |
1224 | get_polymorphic_call_info_for_decl (context, base, |
1225 | context->offset + offset2); | |
7656ee72 | 1226 | return NULL; |
68377e53 JH |
1227 | } |
1228 | else | |
1229 | break; | |
1230 | } | |
1231 | else | |
1232 | break; | |
1233 | } | |
1234 | else if (TREE_CODE (base_pointer) == POINTER_PLUS_EXPR | |
1235 | && tree_fits_uhwi_p (TREE_OPERAND (base_pointer, 1))) | |
1236 | { | |
1237 | context->offset += tree_to_shwi (TREE_OPERAND (base_pointer, 1)) | |
1238 | * BITS_PER_UNIT; | |
1239 | base_pointer = TREE_OPERAND (base_pointer, 0); | |
1240 | } | |
1241 | else | |
1242 | break; | |
1243 | } | |
1244 | while (true); | |
1245 | ||
1246 | /* Try to determine type of the outer object. */ | |
1247 | if (TREE_CODE (base_pointer) == SSA_NAME | |
1248 | && SSA_NAME_IS_DEFAULT_DEF (base_pointer) | |
1249 | && TREE_CODE (SSA_NAME_VAR (base_pointer)) == PARM_DECL) | |
1250 | { | |
1251 | /* See if parameter is THIS pointer of a method. */ | |
1252 | if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE | |
1253 | && SSA_NAME_VAR (base_pointer) == DECL_ARGUMENTS (fndecl)) | |
1254 | { | |
1255 | context->outer_type = TREE_TYPE (TREE_TYPE (base_pointer)); | |
1256 | gcc_assert (TREE_CODE (context->outer_type) == RECORD_TYPE); | |
1257 | ||
1258 | /* Dynamic casting has possibly upcasted the type | |
1259 | in the hiearchy. In this case outer type is less | |
1260 | informative than inner type and we should forget | |
1261 | about it. */ | |
1262 | if (!contains_type_p (context->outer_type, context->offset, | |
1263 | *otr_type)) | |
1264 | { | |
1265 | context->outer_type = NULL; | |
1266 | return base_pointer; | |
1267 | } | |
1268 | ||
1269 | /* If the function is constructor or destructor, then | |
d74db8ff | 1270 | the type is possibly in construction, but we know |
68377e53 JH |
1271 | it is not derived type. */ |
1272 | if (DECL_CXX_CONSTRUCTOR_P (fndecl) | |
1273 | || DECL_CXX_DESTRUCTOR_P (fndecl)) | |
1274 | { | |
1275 | context->maybe_in_construction = true; | |
1276 | context->maybe_derived_type = false; | |
1277 | } | |
1278 | else | |
1279 | { | |
1280 | context->maybe_derived_type = true; | |
1281 | context->maybe_in_construction = false; | |
1282 | } | |
1283 | return base_pointer; | |
1284 | } | |
1285 | /* Non-PODs passed by value are really passed by invisible | |
1286 | reference. In this case we also know the type of the | |
1287 | object. */ | |
1288 | if (DECL_BY_REFERENCE (SSA_NAME_VAR (base_pointer))) | |
1289 | { | |
1290 | context->outer_type = TREE_TYPE (TREE_TYPE (base_pointer)); | |
1291 | gcc_assert (!POINTER_TYPE_P (context->outer_type)); | |
1292 | /* Only type inconsistent programs can have otr_type that is | |
1293 | not part of outer type. */ | |
1294 | if (!contains_type_p (context->outer_type, context->offset, | |
1295 | *otr_type)) | |
1296 | { | |
3e86c6a8 JH |
1297 | /* Use OTR_TOKEN = INT_MAX as a marker of probably type inconsistent |
1298 | code sequences; we arrange the calls to be builtin_unreachable | |
1299 | later. */ | |
1300 | *otr_token = INT_MAX; | |
68377e53 JH |
1301 | return base_pointer; |
1302 | } | |
1303 | context->maybe_derived_type = false; | |
1304 | context->maybe_in_construction = false; | |
1305 | return base_pointer; | |
1306 | } | |
1307 | } | |
1308 | /* TODO: There are multiple ways to derive a type. For instance | |
1309 | if BASE_POINTER is passed to an constructor call prior our refernece. | |
1310 | We do not make this type of flow sensitive analysis yet. */ | |
1311 | return base_pointer; | |
1312 | } | |
1313 | ||
1314 | /* Walk bases of OUTER_TYPE that contain OTR_TYPE at OFFSET. | |
1315 | Lookup their respecitve virtual methods for OTR_TOKEN and OTR_TYPE | |
1316 | and insert them to NODES. | |
1317 | ||
1318 | MATCHED_VTABLES and INSERTED is used to avoid duplicated work. */ | |
1319 | ||
1320 | static void | |
1321 | record_targets_from_bases (tree otr_type, | |
1322 | HOST_WIDE_INT otr_token, | |
1323 | tree outer_type, | |
1324 | HOST_WIDE_INT offset, | |
ec77d61f | 1325 | vec <cgraph_node *> &nodes, |
68377e53 JH |
1326 | pointer_set_t *inserted, |
1327 | pointer_set_t *matched_vtables, | |
1328 | bool *completep) | |
1329 | { | |
1330 | while (true) | |
1331 | { | |
1332 | HOST_WIDE_INT pos, size; | |
1333 | tree base_binfo; | |
1334 | tree fld; | |
1335 | ||
1336 | if (types_same_for_odr (outer_type, otr_type)) | |
1337 | return; | |
1338 | ||
1339 | for (fld = TYPE_FIELDS (outer_type); fld; fld = DECL_CHAIN (fld)) | |
1340 | { | |
1341 | if (TREE_CODE (fld) != FIELD_DECL) | |
1342 | continue; | |
1343 | ||
1344 | pos = int_bit_position (fld); | |
1345 | size = tree_to_shwi (DECL_SIZE (fld)); | |
ec77d61f JH |
1346 | if (pos <= offset && (pos + size) > offset |
1347 | /* Do not get confused by zero sized bases. */ | |
1348 | && polymorphic_type_binfo_p (TYPE_BINFO (TREE_TYPE (fld)))) | |
68377e53 JH |
1349 | break; |
1350 | } | |
1351 | /* Within a class type we should always find correcponding fields. */ | |
1352 | gcc_assert (fld && TREE_CODE (TREE_TYPE (fld)) == RECORD_TYPE); | |
1353 | ||
1354 | /* Nonbasetypes should have been stripped by outer_class_type. */ | |
1355 | gcc_assert (DECL_ARTIFICIAL (fld)); | |
1356 | ||
1357 | outer_type = TREE_TYPE (fld); | |
1358 | offset -= pos; | |
1359 | ||
1360 | base_binfo = get_binfo_at_offset (TYPE_BINFO (outer_type), | |
1361 | offset, otr_type); | |
ec77d61f JH |
1362 | if (!base_binfo) |
1363 | { | |
1364 | gcc_assert (odr_violation_reported); | |
1365 | return; | |
1366 | } | |
68377e53 JH |
1367 | gcc_assert (base_binfo); |
1368 | if (!pointer_set_insert (matched_vtables, BINFO_VTABLE (base_binfo))) | |
1369 | { | |
ec77d61f JH |
1370 | bool can_refer; |
1371 | tree target = gimple_get_virt_method_for_binfo (otr_token, | |
1372 | base_binfo, | |
1373 | &can_refer); | |
1374 | maybe_record_node (nodes, target, inserted, can_refer, completep); | |
68377e53 JH |
1375 | pointer_set_insert (matched_vtables, BINFO_VTABLE (base_binfo)); |
1376 | } | |
1377 | } | |
1378 | } | |
1379 | ||
3462aa02 JH |
1380 | /* When virtual table is removed, we may need to flush the cache. */ |
1381 | ||
1382 | static void | |
2c8326a5 | 1383 | devirt_variable_node_removal_hook (varpool_node *n, |
3462aa02 JH |
1384 | void *d ATTRIBUTE_UNUSED) |
1385 | { | |
1386 | if (cached_polymorphic_call_targets | |
67348ccc DM |
1387 | && DECL_VIRTUAL_P (n->decl) |
1388 | && type_in_anonymous_namespace_p (DECL_CONTEXT (n->decl))) | |
3462aa02 JH |
1389 | free_polymorphic_call_targets_hash (); |
1390 | } | |
1391 | ||
eefe9a99 | 1392 | /* Return vector containing possible targets of polymorphic call of type |
68377e53 JH |
1393 | OTR_TYPE caling method OTR_TOKEN within type of OTR_OUTER_TYPE and OFFSET. |
1394 | If INCLUDE_BASES is true, walk also base types of OUTER_TYPES containig | |
1395 | OTR_TYPE and include their virtual method. This is useful for types | |
1396 | possibly in construction or destruction where the virtual table may | |
1397 | temporarily change to one of base types. INCLUDE_DERIVER_TYPES make | |
1398 | us to walk the inheritance graph for all derivations. | |
1399 | ||
3e86c6a8 JH |
1400 | OTR_TOKEN == INT_MAX is used to mark calls that are provably |
1401 | undefined and should be redirected to unreachable. | |
1402 | ||
add5c763 | 1403 | If COMPLETEP is non-NULL, store true if the list is complete. |
eefe9a99 JH |
1404 | CACHE_TOKEN (if non-NULL) will get stored to an unique ID of entry |
1405 | in the target cache. If user needs to visit every target list | |
1406 | just once, it can memoize them. | |
1407 | ||
ec77d61f JH |
1408 | NONCONSTRUCTION_TARGETS specify number of targets with asumption that |
1409 | the type is not in the construction. Those targets appear first in the | |
1410 | vector returned. | |
1411 | ||
eefe9a99 JH |
1412 | Returned vector is placed into cache. It is NOT caller's responsibility |
1413 | to free it. The vector can be freed on cgraph_remove_node call if | |
1414 | the particular node is a virtual function present in the cache. */ | |
1415 | ||
1416 | vec <cgraph_node *> | |
1417 | possible_polymorphic_call_targets (tree otr_type, | |
1418 | HOST_WIDE_INT otr_token, | |
68377e53 JH |
1419 | ipa_polymorphic_call_context context, |
1420 | bool *completep, | |
ec77d61f JH |
1421 | void **cache_token, |
1422 | int *nonconstruction_targetsp) | |
eefe9a99 JH |
1423 | { |
1424 | static struct cgraph_node_hook_list *node_removal_hook_holder; | |
1425 | pointer_set_t *inserted; | |
1426 | pointer_set_t *matched_vtables; | |
add5c763 | 1427 | vec <cgraph_node *> nodes = vNULL; |
68377e53 | 1428 | odr_type type, outer_type; |
eefe9a99 JH |
1429 | polymorphic_call_target_d key; |
1430 | polymorphic_call_target_d **slot; | |
1431 | unsigned int i; | |
1432 | tree binfo, target; | |
ec77d61f JH |
1433 | bool complete; |
1434 | bool can_refer; | |
eefe9a99 | 1435 | |
3e86c6a8 | 1436 | /* If ODR is not initialized, return empty incomplete list. */ |
79c7de84 EB |
1437 | if (!odr_hash.is_created ()) |
1438 | { | |
1439 | if (completep) | |
1440 | *completep = false; | |
ec77d61f JH |
1441 | if (nonconstruction_targetsp) |
1442 | *nonconstruction_targetsp = 0; | |
79c7de84 EB |
1443 | return nodes; |
1444 | } | |
add5c763 | 1445 | |
3e86c6a8 JH |
1446 | /* If we hit type inconsistency, just return empty list of targets. */ |
1447 | if (otr_token == INT_MAX) | |
1448 | { | |
1449 | if (completep) | |
1450 | *completep = true; | |
1451 | if (nonconstruction_targetsp) | |
1452 | *nonconstruction_targetsp = 0; | |
1453 | return nodes; | |
1454 | } | |
1455 | ||
68377e53 | 1456 | type = get_odr_type (otr_type, true); |
eefe9a99 | 1457 | |
68377e53 | 1458 | /* Lookup the outer class type we want to walk. */ |
3e86c6a8 JH |
1459 | if (context.outer_type |
1460 | && !get_class_context (&context, otr_type)) | |
1461 | { | |
1462 | if (completep) | |
1463 | *completep = false; | |
1464 | if (nonconstruction_targetsp) | |
1465 | *nonconstruction_targetsp = 0; | |
1466 | return nodes; | |
1467 | } | |
eefe9a99 | 1468 | |
79c7de84 | 1469 | /* We canonicalize our query, so we do not need extra hashtable entries. */ |
68377e53 JH |
1470 | |
1471 | /* Without outer type, we have no use for offset. Just do the | |
1472 | basic search from innter type */ | |
1473 | if (!context.outer_type) | |
1474 | { | |
1475 | context.outer_type = otr_type; | |
1476 | context.offset = 0; | |
1477 | } | |
1478 | /* We need to update our hiearchy if the type does not exist. */ | |
1479 | outer_type = get_odr_type (context.outer_type, true); | |
1480 | /* If outer and inner type match, there are no bases to see. */ | |
1481 | if (type == outer_type) | |
1482 | context.maybe_in_construction = false; | |
ec77d61f | 1483 | /* If the type is complete, there are no derivations. */ |
68377e53 JH |
1484 | if (TYPE_FINAL_P (outer_type->type)) |
1485 | context.maybe_derived_type = false; | |
eefe9a99 JH |
1486 | |
1487 | /* Initialize query cache. */ | |
1488 | if (!cached_polymorphic_call_targets) | |
1489 | { | |
1490 | cached_polymorphic_call_targets = pointer_set_create (); | |
1491 | polymorphic_call_target_hash.create (23); | |
1492 | if (!node_removal_hook_holder) | |
3462aa02 JH |
1493 | { |
1494 | node_removal_hook_holder = | |
1495 | cgraph_add_node_removal_hook (&devirt_node_removal_hook, NULL); | |
1496 | varpool_add_node_removal_hook (&devirt_variable_node_removal_hook, | |
1497 | NULL); | |
1498 | } | |
eefe9a99 JH |
1499 | } |
1500 | ||
1501 | /* Lookup cached answer. */ | |
1502 | key.type = type; | |
1503 | key.otr_token = otr_token; | |
68377e53 | 1504 | key.context = context; |
eefe9a99 JH |
1505 | slot = polymorphic_call_target_hash.find_slot (&key, INSERT); |
1506 | if (cache_token) | |
1507 | *cache_token = (void *)*slot; | |
1508 | if (*slot) | |
68377e53 JH |
1509 | { |
1510 | if (completep) | |
ec77d61f JH |
1511 | *completep = (*slot)->complete; |
1512 | if (nonconstruction_targetsp) | |
1513 | *nonconstruction_targetsp = (*slot)->nonconstruction_targets; | |
68377e53 JH |
1514 | return (*slot)->targets; |
1515 | } | |
1516 | ||
ec77d61f | 1517 | complete = true; |
eefe9a99 JH |
1518 | |
1519 | /* Do actual search. */ | |
1520 | timevar_push (TV_IPA_VIRTUAL_CALL); | |
1521 | *slot = XCNEW (polymorphic_call_target_d); | |
1522 | if (cache_token) | |
68377e53 | 1523 | *cache_token = (void *)*slot; |
eefe9a99 JH |
1524 | (*slot)->type = type; |
1525 | (*slot)->otr_token = otr_token; | |
68377e53 | 1526 | (*slot)->context = context; |
eefe9a99 JH |
1527 | |
1528 | inserted = pointer_set_create (); | |
1529 | matched_vtables = pointer_set_create (); | |
1530 | ||
1531 | /* First see virtual method of type itself. */ | |
68377e53 JH |
1532 | binfo = get_binfo_at_offset (TYPE_BINFO (outer_type->type), |
1533 | context.offset, otr_type); | |
ec77d61f JH |
1534 | if (binfo) |
1535 | target = gimple_get_virt_method_for_binfo (otr_token, binfo, | |
1536 | &can_refer); | |
1537 | else | |
68377e53 | 1538 | { |
ec77d61f JH |
1539 | gcc_assert (odr_violation_reported); |
1540 | target = NULL; | |
1541 | } | |
68377e53 | 1542 | |
ec77d61f JH |
1543 | maybe_record_node (nodes, target, inserted, can_refer, &complete); |
1544 | ||
1545 | if (target) | |
1546 | { | |
1547 | /* In the case we get complete method, we don't need | |
68377e53 JH |
1548 | to walk derivations. */ |
1549 | if (DECL_FINAL_P (target)) | |
1550 | context.maybe_derived_type = false; | |
1551 | } | |
ec77d61f JH |
1552 | else |
1553 | gcc_assert (!complete); | |
79c7de84 | 1554 | |
eefe9a99 JH |
1555 | pointer_set_insert (matched_vtables, BINFO_VTABLE (binfo)); |
1556 | ||
ec77d61f | 1557 | /* Next walk recursively all derived types. */ |
68377e53 JH |
1558 | if (context.maybe_derived_type) |
1559 | { | |
1560 | /* For anonymous namespace types we can attempt to build full type. | |
1561 | All derivations must be in this unit (unless we see partial unit). */ | |
1562 | if (!type->anonymous_namespace || flag_ltrans) | |
ec77d61f | 1563 | complete = false; |
68377e53 JH |
1564 | for (i = 0; i < outer_type->derived_types.length(); i++) |
1565 | possible_polymorphic_call_targets_1 (nodes, inserted, | |
1566 | matched_vtables, | |
79c7de84 EB |
1567 | otr_type, |
1568 | outer_type->derived_types[i], | |
68377e53 | 1569 | otr_token, outer_type->type, |
ec77d61f | 1570 | context.offset, &complete); |
68377e53 | 1571 | } |
79c7de84 | 1572 | |
ec77d61f JH |
1573 | /* Finally walk bases, if asked to. */ |
1574 | (*slot)->nonconstruction_targets = nodes.length(); | |
1575 | if (context.maybe_in_construction) | |
1576 | record_targets_from_bases (otr_type, otr_token, outer_type->type, | |
1577 | context.offset, nodes, inserted, | |
1578 | matched_vtables, &complete); | |
1579 | ||
eefe9a99 | 1580 | (*slot)->targets = nodes; |
ec77d61f | 1581 | (*slot)->complete = complete; |
68377e53 | 1582 | if (completep) |
ec77d61f JH |
1583 | *completep = complete; |
1584 | if (nonconstruction_targetsp) | |
1585 | *nonconstruction_targetsp = (*slot)->nonconstruction_targets; | |
eefe9a99 JH |
1586 | |
1587 | pointer_set_destroy (inserted); | |
1588 | pointer_set_destroy (matched_vtables); | |
1589 | timevar_pop (TV_IPA_VIRTUAL_CALL); | |
1590 | return nodes; | |
1591 | } | |
1592 | ||
1593 | /* Dump all possible targets of a polymorphic call. */ | |
1594 | ||
1595 | void | |
1596 | dump_possible_polymorphic_call_targets (FILE *f, | |
68377e53 JH |
1597 | tree otr_type, |
1598 | HOST_WIDE_INT otr_token, | |
1599 | const ipa_polymorphic_call_context &ctx) | |
eefe9a99 JH |
1600 | { |
1601 | vec <cgraph_node *> targets; | |
1602 | bool final; | |
1603 | odr_type type = get_odr_type (otr_type, false); | |
1604 | unsigned int i; | |
ec77d61f | 1605 | int nonconstruction; |
eefe9a99 JH |
1606 | |
1607 | if (!type) | |
1608 | return; | |
1609 | targets = possible_polymorphic_call_targets (otr_type, otr_token, | |
68377e53 | 1610 | ctx, |
ec77d61f | 1611 | &final, NULL, &nonconstruction); |
68377e53 | 1612 | fprintf (f, " Targets of polymorphic call of type %i:", type->id); |
eefe9a99 | 1613 | print_generic_expr (f, type->type, TDF_SLIM); |
ec77d61f JH |
1614 | fprintf (f, " token %i\n", (int)otr_token); |
1615 | if (ctx.outer_type || ctx.offset) | |
1616 | { | |
1617 | fprintf (f, " Contained in type:"); | |
1618 | print_generic_expr (f, ctx.outer_type, TDF_SLIM); | |
1619 | fprintf (f, " at offset "HOST_WIDE_INT_PRINT_DEC"\n", | |
1620 | ctx.offset); | |
1621 | } | |
1622 | ||
1623 | fprintf (f, " %s%s%s\n ", | |
1624 | final ? "This is a complete list." : | |
68377e53 JH |
1625 | "This is partial list; extra targets may be defined in other units.", |
1626 | ctx.maybe_in_construction ? " (base types included)" : "", | |
1627 | ctx.maybe_derived_type ? " (derived types included)" : ""); | |
eefe9a99 | 1628 | for (i = 0; i < targets.length (); i++) |
ec77d61f JH |
1629 | { |
1630 | char *name = NULL; | |
1631 | if (i == (unsigned)nonconstruction) | |
1632 | fprintf (f, "\n If the type is in construction," | |
1633 | " then additional tarets are:\n" | |
1634 | " "); | |
1635 | if (in_lto_p) | |
1636 | name = cplus_demangle_v3 (targets[i]->asm_name (), 0); | |
1637 | fprintf (f, " %s/%i", name ? name : targets[i]->name (), targets[i]->order); | |
1638 | if (in_lto_p) | |
1639 | free (name); | |
1640 | if (!targets[i]->definition) | |
1641 | fprintf (f, " (no definition%s)", | |
1642 | DECL_DECLARED_INLINE_P (targets[i]->decl) | |
1643 | ? " inline" : ""); | |
1644 | } | |
68377e53 | 1645 | fprintf (f, "\n\n"); |
eefe9a99 JH |
1646 | } |
1647 | ||
0e1474e5 JH |
1648 | |
1649 | /* Return true if N can be possibly target of a polymorphic call of | |
1650 | OTR_TYPE/OTR_TOKEN. */ | |
1651 | ||
1652 | bool | |
1653 | possible_polymorphic_call_target_p (tree otr_type, | |
1654 | HOST_WIDE_INT otr_token, | |
68377e53 | 1655 | const ipa_polymorphic_call_context &ctx, |
0e1474e5 JH |
1656 | struct cgraph_node *n) |
1657 | { | |
1658 | vec <cgraph_node *> targets; | |
1659 | unsigned int i; | |
68377e53 | 1660 | enum built_in_function fcode; |
450ad0cd | 1661 | bool final; |
0e1474e5 | 1662 | |
68377e53 JH |
1663 | if (TREE_CODE (TREE_TYPE (n->decl)) == FUNCTION_TYPE |
1664 | && ((fcode = DECL_FUNCTION_CODE (n->decl)) | |
1665 | == BUILT_IN_UNREACHABLE | |
1666 | || fcode == BUILT_IN_TRAP)) | |
1667 | return true; | |
1668 | ||
0e1474e5 JH |
1669 | if (!odr_hash.is_created ()) |
1670 | return true; | |
68377e53 | 1671 | targets = possible_polymorphic_call_targets (otr_type, otr_token, ctx, &final); |
0e1474e5 | 1672 | for (i = 0; i < targets.length (); i++) |
68377e53 | 1673 | if (symtab_semantically_equivalent_p (n, targets[i])) |
0e1474e5 | 1674 | return true; |
450ad0cd JH |
1675 | |
1676 | /* At a moment we allow middle end to dig out new external declarations | |
1677 | as a targets of polymorphic calls. */ | |
67348ccc | 1678 | if (!final && !n->definition) |
450ad0cd | 1679 | return true; |
0e1474e5 JH |
1680 | return false; |
1681 | } | |
1682 | ||
1683 | ||
1684 | /* After callgraph construction new external nodes may appear. | |
1685 | Add them into the graph. */ | |
1686 | ||
1687 | void | |
1688 | update_type_inheritance_graph (void) | |
1689 | { | |
1690 | struct cgraph_node *n; | |
1691 | ||
1692 | if (!odr_hash.is_created ()) | |
1693 | return; | |
1694 | free_polymorphic_call_targets_hash (); | |
1695 | timevar_push (TV_IPA_INHERITANCE); | |
68377e53 | 1696 | /* We reconstruct the graph starting from types of all methods seen in the |
0e1474e5 JH |
1697 | the unit. */ |
1698 | FOR_EACH_FUNCTION (n) | |
67348ccc DM |
1699 | if (DECL_VIRTUAL_P (n->decl) |
1700 | && !n->definition | |
1701 | && symtab_real_symbol_p (n)) | |
1702 | get_odr_type (method_class_type (TREE_TYPE (n->decl)), true); | |
0e1474e5 JH |
1703 | timevar_pop (TV_IPA_INHERITANCE); |
1704 | } | |
bbc9396b JH |
1705 | |
1706 | ||
1707 | /* Return true if N looks like likely target of a polymorphic call. | |
1708 | Rule out cxa_pure_virtual, noreturns, function declared cold and | |
1709 | other obvious cases. */ | |
1710 | ||
1711 | bool | |
1712 | likely_target_p (struct cgraph_node *n) | |
1713 | { | |
1714 | int flags; | |
1715 | /* cxa_pure_virtual and similar things are not likely. */ | |
67348ccc | 1716 | if (TREE_CODE (TREE_TYPE (n->decl)) != METHOD_TYPE) |
bbc9396b | 1717 | return false; |
67348ccc | 1718 | flags = flags_from_decl_or_type (n->decl); |
bbc9396b JH |
1719 | if (flags & ECF_NORETURN) |
1720 | return false; | |
1721 | if (lookup_attribute ("cold", | |
67348ccc | 1722 | DECL_ATTRIBUTES (n->decl))) |
bbc9396b JH |
1723 | return false; |
1724 | if (n->frequency < NODE_FREQUENCY_NORMAL) | |
1725 | return false; | |
1726 | return true; | |
1727 | } | |
1728 | ||
1729 | /* The ipa-devirt pass. | |
3462aa02 JH |
1730 | When polymorphic call has only one likely target in the unit, |
1731 | turn it into speculative call. */ | |
bbc9396b JH |
1732 | |
1733 | static unsigned int | |
1734 | ipa_devirt (void) | |
1735 | { | |
1736 | struct cgraph_node *n; | |
1737 | struct pointer_set_t *bad_call_targets = pointer_set_create (); | |
1738 | struct cgraph_edge *e; | |
1739 | ||
1740 | int npolymorphic = 0, nspeculated = 0, nconverted = 0, ncold = 0; | |
1741 | int nmultiple = 0, noverwritable = 0, ndevirtualized = 0, nnotdefined = 0; | |
570215f9 | 1742 | int nwrong = 0, nok = 0, nexternal = 0, nartificial = 0; |
bbc9396b JH |
1743 | |
1744 | FOR_EACH_DEFINED_FUNCTION (n) | |
1745 | { | |
1746 | bool update = false; | |
1747 | if (dump_file && n->indirect_calls) | |
1748 | fprintf (dump_file, "\n\nProcesing function %s/%i\n", | |
fec39fa6 | 1749 | n->name (), n->order); |
bbc9396b JH |
1750 | for (e = n->indirect_calls; e; e = e->next_callee) |
1751 | if (e->indirect_info->polymorphic) | |
1752 | { | |
1753 | struct cgraph_node *likely_target = NULL; | |
1754 | void *cache_token; | |
1755 | bool final; | |
ec77d61f | 1756 | int nonconstruction_targets; |
bbc9396b JH |
1757 | vec <cgraph_node *>targets |
1758 | = possible_polymorphic_call_targets | |
ec77d61f | 1759 | (e, &final, &cache_token, &nonconstruction_targets); |
bbc9396b JH |
1760 | unsigned int i; |
1761 | ||
1762 | if (dump_file) | |
1763 | dump_possible_polymorphic_call_targets | |
1764 | (dump_file, e); | |
3462aa02 | 1765 | |
bbc9396b JH |
1766 | npolymorphic++; |
1767 | ||
bbc9396b JH |
1768 | if (!cgraph_maybe_hot_edge_p (e)) |
1769 | { | |
1770 | if (dump_file) | |
ec77d61f | 1771 | fprintf (dump_file, "Call is cold\n\n"); |
bbc9396b JH |
1772 | ncold++; |
1773 | continue; | |
1774 | } | |
1775 | if (e->speculative) | |
1776 | { | |
1777 | if (dump_file) | |
ec77d61f | 1778 | fprintf (dump_file, "Call is aready speculated\n\n"); |
bbc9396b JH |
1779 | nspeculated++; |
1780 | ||
1781 | /* When dumping see if we agree with speculation. */ | |
1782 | if (!dump_file) | |
1783 | continue; | |
1784 | } | |
1785 | if (pointer_set_contains (bad_call_targets, | |
1786 | cache_token)) | |
1787 | { | |
1788 | if (dump_file) | |
ec77d61f | 1789 | fprintf (dump_file, "Target list is known to be useless\n\n"); |
bbc9396b JH |
1790 | nmultiple++; |
1791 | continue; | |
1792 | } | |
c3284718 | 1793 | for (i = 0; i < targets.length (); i++) |
bbc9396b JH |
1794 | if (likely_target_p (targets[i])) |
1795 | { | |
1796 | if (likely_target) | |
1797 | { | |
ec77d61f JH |
1798 | if (i < (unsigned) nonconstruction_targets) |
1799 | { | |
1800 | likely_target = NULL; | |
1801 | if (dump_file) | |
1802 | fprintf (dump_file, "More than one likely target\n\n"); | |
1803 | nmultiple++; | |
1804 | } | |
bbc9396b JH |
1805 | break; |
1806 | } | |
1807 | likely_target = targets[i]; | |
1808 | } | |
1809 | if (!likely_target) | |
1810 | { | |
1811 | pointer_set_insert (bad_call_targets, cache_token); | |
1812 | continue; | |
1813 | } | |
1814 | /* This is reached only when dumping; check if we agree or disagree | |
1815 | with the speculation. */ | |
1816 | if (e->speculative) | |
1817 | { | |
1818 | struct cgraph_edge *e2; | |
1819 | struct ipa_ref *ref; | |
1820 | cgraph_speculative_call_info (e, e2, e, ref); | |
1821 | if (cgraph_function_or_thunk_node (e2->callee, NULL) | |
1822 | == cgraph_function_or_thunk_node (likely_target, NULL)) | |
1823 | { | |
ec77d61f | 1824 | fprintf (dump_file, "We agree with speculation\n\n"); |
bbc9396b JH |
1825 | nok++; |
1826 | } | |
1827 | else | |
1828 | { | |
ec77d61f | 1829 | fprintf (dump_file, "We disagree with speculation\n\n"); |
bbc9396b JH |
1830 | nwrong++; |
1831 | } | |
1832 | continue; | |
1833 | } | |
67348ccc | 1834 | if (!likely_target->definition) |
bbc9396b JH |
1835 | { |
1836 | if (dump_file) | |
ec77d61f | 1837 | fprintf (dump_file, "Target is not an definition\n\n"); |
bbc9396b JH |
1838 | nnotdefined++; |
1839 | continue; | |
1840 | } | |
1841 | /* Do not introduce new references to external symbols. While we | |
1842 | can handle these just well, it is common for programs to | |
1843 | incorrectly with headers defining methods they are linked | |
1844 | with. */ | |
67348ccc | 1845 | if (DECL_EXTERNAL (likely_target->decl)) |
bbc9396b JH |
1846 | { |
1847 | if (dump_file) | |
ec77d61f | 1848 | fprintf (dump_file, "Target is external\n\n"); |
bbc9396b JH |
1849 | nexternal++; |
1850 | continue; | |
1851 | } | |
570215f9 JM |
1852 | /* Don't use an implicitly-declared destructor (c++/58678). */ |
1853 | struct cgraph_node *non_thunk_target | |
1854 | = cgraph_function_node (likely_target); | |
1855 | if (DECL_ARTIFICIAL (non_thunk_target->decl) | |
1856 | && DECL_COMDAT (non_thunk_target->decl)) | |
1857 | { | |
1858 | if (dump_file) | |
1859 | fprintf (dump_file, "Target is artificial\n\n"); | |
1860 | nartificial++; | |
1861 | continue; | |
1862 | } | |
bbc9396b JH |
1863 | if (cgraph_function_body_availability (likely_target) |
1864 | <= AVAIL_OVERWRITABLE | |
67348ccc | 1865 | && symtab_can_be_discarded (likely_target)) |
bbc9396b JH |
1866 | { |
1867 | if (dump_file) | |
ec77d61f | 1868 | fprintf (dump_file, "Target is overwritable\n\n"); |
bbc9396b JH |
1869 | noverwritable++; |
1870 | continue; | |
1871 | } | |
1872 | else | |
1873 | { | |
1874 | if (dump_file) | |
1875 | fprintf (dump_file, | |
ec77d61f | 1876 | "Speculatively devirtualizing call in %s/%i to %s/%i\n\n", |
fec39fa6 TS |
1877 | n->name (), n->order, |
1878 | likely_target->name (), | |
67348ccc DM |
1879 | likely_target->order); |
1880 | if (!symtab_can_be_discarded (likely_target)) | |
5b79657a JH |
1881 | { |
1882 | cgraph_node *alias; | |
1883 | alias = cgraph (symtab_nonoverwritable_alias | |
67348ccc | 1884 | (likely_target)); |
5b79657a JH |
1885 | if (alias) |
1886 | likely_target = alias; | |
1887 | } | |
bbc9396b JH |
1888 | nconverted++; |
1889 | update = true; | |
1890 | cgraph_turn_edge_to_speculative | |
1891 | (e, likely_target, e->count * 8 / 10, e->frequency * 8 / 10); | |
1892 | } | |
1893 | } | |
1894 | if (update) | |
1895 | inline_update_overall_summary (n); | |
1896 | } | |
1897 | pointer_set_destroy (bad_call_targets); | |
1898 | ||
1899 | if (dump_file) | |
1900 | fprintf (dump_file, | |
1901 | "%i polymorphic calls, %i devirtualized," | |
1902 | " %i speculatively devirtualized, %i cold\n" | |
1903 | "%i have multiple targets, %i overwritable," | |
1904 | " %i already speculated (%i agree, %i disagree)," | |
570215f9 | 1905 | " %i external, %i not defined, %i artificial\n", |
bbc9396b JH |
1906 | npolymorphic, ndevirtualized, nconverted, ncold, |
1907 | nmultiple, noverwritable, nspeculated, nok, nwrong, | |
570215f9 | 1908 | nexternal, nnotdefined, nartificial); |
bbc9396b JH |
1909 | return ndevirtualized ? TODO_remove_functions : 0; |
1910 | } | |
1911 | ||
a88bf705 | 1912 | /* Gate for speculative IPA devirtualization optimization. */ |
bbc9396b JH |
1913 | |
1914 | static bool | |
1915 | gate_ipa_devirt (void) | |
1916 | { | |
a88bf705 JJ |
1917 | return (flag_devirtualize |
1918 | && flag_devirtualize_speculatively | |
1919 | && optimize); | |
bbc9396b JH |
1920 | } |
1921 | ||
1922 | namespace { | |
1923 | ||
1924 | const pass_data pass_data_ipa_devirt = | |
1925 | { | |
1926 | IPA_PASS, /* type */ | |
1927 | "devirt", /* name */ | |
1928 | OPTGROUP_NONE, /* optinfo_flags */ | |
1929 | true, /* has_gate */ | |
1930 | true, /* has_execute */ | |
1931 | TV_IPA_DEVIRT, /* tv_id */ | |
1932 | 0, /* properties_required */ | |
1933 | 0, /* properties_provided */ | |
1934 | 0, /* properties_destroyed */ | |
1935 | 0, /* todo_flags_start */ | |
1936 | ( TODO_dump_symtab ), /* todo_flags_finish */ | |
1937 | }; | |
1938 | ||
1939 | class pass_ipa_devirt : public ipa_opt_pass_d | |
1940 | { | |
1941 | public: | |
c3284718 RS |
1942 | pass_ipa_devirt (gcc::context *ctxt) |
1943 | : ipa_opt_pass_d (pass_data_ipa_devirt, ctxt, | |
1944 | NULL, /* generate_summary */ | |
1945 | NULL, /* write_summary */ | |
1946 | NULL, /* read_summary */ | |
1947 | NULL, /* write_optimization_summary */ | |
1948 | NULL, /* read_optimization_summary */ | |
1949 | NULL, /* stmt_fixup */ | |
1950 | 0, /* function_transform_todo_flags_start */ | |
1951 | NULL, /* function_transform */ | |
1952 | NULL) /* variable_transform */ | |
bbc9396b JH |
1953 | {} |
1954 | ||
1955 | /* opt_pass methods: */ | |
1956 | bool gate () { return gate_ipa_devirt (); } | |
1957 | unsigned int execute () { return ipa_devirt (); } | |
1958 | ||
1959 | }; // class pass_ipa_devirt | |
1960 | ||
1961 | } // anon namespace | |
1962 | ||
1963 | ipa_opt_pass_d * | |
1964 | make_pass_ipa_devirt (gcc::context *ctxt) | |
1965 | { | |
1966 | return new pass_ipa_devirt (ctxt); | |
1967 | } | |
1968 | ||
eefe9a99 | 1969 | #include "gt-ipa-devirt.h" |