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