1 /* Basic IPA utilities for type inheritance graph construction and
3 Copyright (C) 2013-2014 Free Software Foundation, Inc.
4 Contributed by Jan Hubicka
6 This file is part of GCC.
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
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
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/>. */
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.
40 This is the Gimple representation of type information of a polymorphic call.
41 It contains two parameters:
42 otr_type is a type of class whose method is called.
43 otr_token is the index into virtual table where address is taken.
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.
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
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
58 virtual table of the base type. Also BINFO_OFFSET specifies
59 offset of the base within the type.
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).
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
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
75 or from DECL_VINDEX of a given virtual table.
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.
84 build_type_inheritance_graph triggers a construction of the type inheritance
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
89 inserted into the graph. Also types without virtual methods are not
90 represented at all, though it may be easy to add this.
92 The inheritance graph is represented as follows:
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)
98 Edges are represented by odr_type->base and odr_type->derived_types.
99 At the moment we do not track offsets of types for multiple inheritance.
102 possible_polymorphic_call_targets returns, given an parameters found in
103 indirect polymorphic edge all possible polymorphic call targets of the call.
105 pass_ipa_devirt performs simple speculative devirtualization.
110 #include "coretypes.h"
113 #include "print-tree.h"
117 #include "tree-pass.h"
118 #include "hash-set.h"
120 #include "hash-table.h"
122 #include "tree-pretty-print.h"
123 #include "ipa-utils.h"
124 #include "tree-ssa-alias.h"
125 #include "internal-fn.h"
126 #include "gimple-fold.h"
127 #include "gimple-expr.h"
129 #include "ipa-inline.h"
130 #include "diagnostic.h"
131 #include "tree-dfa.h"
132 #include "demangle.h"
134 #include "stor-layout.h"
136 #include "hash-map.h"
138 static bool odr_types_equivalent_p (tree
, tree
, bool, bool *,
141 static bool odr_violation_reported
= false;
143 /* Dummy polymorphic call context. */
145 const ipa_polymorphic_call_context ipa_dummy_polymorphic_call_context
146 = {0, 0, NULL
, NULL
, false, true, true};
148 /* Pointer set of all call targets appearing in the cache. */
149 static hash_set
<cgraph_node
*> *cached_polymorphic_call_targets
;
151 /* The node of type inheritance graph. For each type unique in
152 One Defintion Rule (ODR) sense, we produce one node linking all
153 main variants of types equivalent to it, bases and derived types. */
155 struct GTY(()) odr_type_d
159 /* All bases; built only for main variants of types */
160 vec
<odr_type
> GTY((skip
)) bases
;
161 /* All derrived types with virtual methods seen in unit;
162 built only for main variants oftypes */
163 vec
<odr_type
> GTY((skip
)) derived_types
;
165 /* All equivalent types, if more than one. */
166 vec
<tree
, va_gc
> *types
;
167 /* Set of all equivalent types, if NON-NULL. */
168 hash_set
<tree
> * GTY((skip
)) types_set
;
170 /* Unique ID indexing the type in odr_types array. */
172 /* Is it in anonymous namespace? */
173 bool anonymous_namespace
;
174 /* Do we know about all derivations of given type? */
175 bool all_derivations_known
;
176 /* Did we report ODR violation here? */
180 static bool contains_type_p (tree
, HOST_WIDE_INT
, tree
);
183 /* Return true if BINFO corresponds to a type with virtual methods.
185 Every type has several BINFOs. One is the BINFO associated by the type
186 while other represents bases of derived types. The BINFOs representing
187 bases do not have BINFO_VTABLE pointer set when this is the single
188 inheritance (because vtables are shared). Look up the BINFO of type
189 and check presence of its vtable. */
192 polymorphic_type_binfo_p (tree binfo
)
194 /* See if BINFO's type has an virtual table associtated with it. */
195 return BINFO_VTABLE (TYPE_BINFO (BINFO_TYPE (binfo
)));
198 /* Return TRUE if all derived types of T are known and thus
199 we may consider the walk of derived type complete.
201 This is typically true only for final anonymous namespace types and types
202 defined within functions (that may be COMDAT and thus shared across units,
203 but with the same set of derived types). */
206 type_all_derivations_known_p (tree t
)
208 if (TYPE_FINAL_P (t
))
212 if (type_in_anonymous_namespace_p (t
))
214 return (decl_function_context (TYPE_NAME (t
)) != NULL
);
217 /* Return TURE if type's constructors are all visible. */
220 type_all_ctors_visible_p (tree t
)
223 && cgraph_state
>= CGRAPH_STATE_CONSTRUCTION
224 /* We can not always use type_all_derivations_known_p.
225 For function local types we must assume case where
226 the function is COMDAT and shared in between units.
228 TODO: These cases are quite easy to get, but we need
229 to keep track of C++ privatizing via -Wno-weak
230 as well as the IPA privatizing. */
231 && type_in_anonymous_namespace_p (t
);
234 /* Return TRUE if type may have instance. */
237 type_possibly_instantiated_p (tree t
)
242 /* TODO: Add abstract types here. */
243 if (!type_all_ctors_visible_p (t
))
246 vtable
= BINFO_VTABLE (TYPE_BINFO (t
));
247 if (TREE_CODE (vtable
) == POINTER_PLUS_EXPR
)
248 vtable
= TREE_OPERAND (TREE_OPERAND (vtable
, 0), 0);
249 vnode
= varpool_node::get (vtable
);
250 return vnode
&& vnode
->definition
;
253 /* One Definition Rule hashtable helpers. */
257 typedef odr_type_d value_type
;
258 typedef union tree_node compare_type
;
259 static inline hashval_t
hash (const value_type
*);
260 static inline bool equal (const value_type
*, const compare_type
*);
261 static inline void remove (value_type
*);
264 /* Return type that was declared with T's name so that T is an
265 qualified variant of it. */
268 main_odr_variant (const_tree t
)
270 if (TYPE_NAME (t
) && TREE_CODE (TYPE_NAME (t
)) == TYPE_DECL
)
271 return TREE_TYPE (TYPE_NAME (t
));
272 /* Unnamed types and non-C++ produced types can be compared by variants. */
274 return TYPE_MAIN_VARIANT (t
);
277 /* Produce hash based on type name. */
280 hash_type_name (tree t
)
282 gcc_checking_assert (main_odr_variant (t
) == t
);
284 /* If not in LTO, all main variants are unique, so we can do
287 return htab_hash_pointer (t
);
289 /* Anonymous types are unique. */
290 if (type_in_anonymous_namespace_p (t
))
291 return htab_hash_pointer (t
);
293 /* For polymorphic types, we can simply hash the virtual table. */
294 if (TREE_CODE (t
) == RECORD_TYPE
295 && TYPE_BINFO (t
) && BINFO_VTABLE (TYPE_BINFO (t
)))
297 tree v
= BINFO_VTABLE (TYPE_BINFO (t
));
300 if (TREE_CODE (v
) == POINTER_PLUS_EXPR
)
302 hash
= TREE_INT_CST_LOW (TREE_OPERAND (v
, 1));
303 v
= TREE_OPERAND (TREE_OPERAND (v
, 0), 0);
306 v
= DECL_ASSEMBLER_NAME (v
);
307 hash
= iterative_hash_hashval_t (hash
, htab_hash_pointer (v
));
311 /* Rest is not implemented yet. */
315 /* Return the computed hashcode for ODR_TYPE. */
318 odr_hasher::hash (const value_type
*odr_type
)
320 return hash_type_name (odr_type
->type
);
323 /* For languages with One Definition Rule, work out if
324 types are the same based on their name.
326 This is non-trivial for LTO where minnor differences in
327 the type representation may have prevented type merging
328 to merge two copies of otherwise equivalent type.
330 Until we start streaming mangled type names, this function works
331 only for polymorphic types. */
334 types_same_for_odr (const_tree type1
, const_tree type2
)
336 gcc_checking_assert (TYPE_P (type1
) && TYPE_P (type2
));
338 type1
= main_odr_variant (type1
);
339 type2
= main_odr_variant (type2
);
347 /* Check for anonymous namespaces. Those have !TREE_PUBLIC
348 on the corresponding TYPE_STUB_DECL. */
349 if (type_in_anonymous_namespace_p (type1
)
350 || type_in_anonymous_namespace_p (type2
))
353 /* See if types are obvoiusly different (i.e. different codes
354 or polymorphis wrt non-polymorphic). This is not strictly correct
355 for ODR violating programs, but we can't do better without streaming
357 if (TREE_CODE (type1
) != TREE_CODE (type2
))
359 if (TREE_CODE (type1
) == RECORD_TYPE
360 && (TYPE_BINFO (type1
) == NULL_TREE
) != (TYPE_BINFO (type1
) == NULL_TREE
))
362 if (TREE_CODE (type1
) == RECORD_TYPE
&& TYPE_BINFO (type1
)
363 && (BINFO_VTABLE (TYPE_BINFO (type1
)) == NULL_TREE
)
364 != (BINFO_VTABLE (TYPE_BINFO (type2
)) == NULL_TREE
))
367 /* At the moment we have no way to establish ODR equivlaence at LTO
368 other than comparing virtual table pointrs of polymorphic types.
369 Eventually we should start saving mangled names in TYPE_NAME.
370 Then this condition will become non-trivial. */
372 if (TREE_CODE (type1
) == RECORD_TYPE
373 && TYPE_BINFO (type1
) && TYPE_BINFO (type2
)
374 && BINFO_VTABLE (TYPE_BINFO (type1
))
375 && BINFO_VTABLE (TYPE_BINFO (type2
)))
377 tree v1
= BINFO_VTABLE (TYPE_BINFO (type1
));
378 tree v2
= BINFO_VTABLE (TYPE_BINFO (type2
));
379 gcc_assert (TREE_CODE (v1
) == POINTER_PLUS_EXPR
380 && TREE_CODE (v2
) == POINTER_PLUS_EXPR
);
381 return (operand_equal_p (TREE_OPERAND (v1
, 1),
382 TREE_OPERAND (v2
, 1), 0)
383 && DECL_ASSEMBLER_NAME
384 (TREE_OPERAND (TREE_OPERAND (v1
, 0), 0))
385 == DECL_ASSEMBLER_NAME
386 (TREE_OPERAND (TREE_OPERAND (v2
, 0), 0)));
392 /* Compare types T1 and T2 and return true if they are
396 odr_hasher::equal (const value_type
*t1
, const compare_type
*ct2
)
398 tree t2
= const_cast <tree
> (ct2
);
400 gcc_checking_assert (main_odr_variant (t2
) == t2
);
405 return types_same_for_odr (t1
->type
, t2
);
408 /* Free ODR type V. */
411 odr_hasher::remove (value_type
*v
)
414 v
->derived_types
.release ();
420 /* ODR type hash used to lookup ODR type based on tree type node. */
422 typedef hash_table
<odr_hasher
> odr_hash_type
;
423 static odr_hash_type
*odr_hash
;
425 /* ODR types are also stored into ODR_TYPE vector to allow consistent
426 walking. Bases appear before derived types. Vector is garbage collected
427 so we won't end up visiting empty types. */
429 static GTY(()) vec
<odr_type
, va_gc
> *odr_types_ptr
;
430 #define odr_types (*odr_types_ptr)
432 /* Set TYPE_BINFO of TYPE and its variants to BINFO. */
434 set_type_binfo (tree type
, tree binfo
)
436 for (; type
; type
= TYPE_NEXT_VARIANT (type
))
437 if (COMPLETE_TYPE_P (type
))
438 TYPE_BINFO (type
) = binfo
;
440 gcc_assert (!TYPE_BINFO (type
));
443 /* Compare T2 and T2 based on name or structure. */
446 odr_subtypes_equivalent_p (tree t1
, tree t2
, hash_set
<tree
> *visited
)
450 /* This can happen in incomplete types that should be handled earlier. */
451 gcc_assert (t1
&& t2
);
453 t1
= main_odr_variant (t1
);
454 t2
= main_odr_variant (t2
);
457 if (TREE_CODE (t1
) != TREE_CODE (t2
))
459 if ((TYPE_NAME (t1
) == NULL_TREE
) != (TYPE_NAME (t2
) == NULL_TREE
))
461 if (TYPE_NAME (t1
) && DECL_NAME (TYPE_NAME (t1
)) != DECL_NAME (TYPE_NAME (t2
)))
464 /* Anonymous namespace types must match exactly. */
465 an1
= type_in_anonymous_namespace_p (t1
);
466 an2
= type_in_anonymous_namespace_p (t2
);
467 if (an1
!= an2
|| an1
)
470 /* For types where we can not establish ODR equivalency, recurse and deeply
472 if (TREE_CODE (t1
) != RECORD_TYPE
473 || !TYPE_BINFO (t1
) || !TYPE_BINFO (t2
)
474 || !polymorphic_type_binfo_p (TYPE_BINFO (t1
))
475 || !polymorphic_type_binfo_p (TYPE_BINFO (t2
)))
477 /* This should really be a pair hash, but for the moment we do not need
478 100% reliability and it would be better to compare all ODR types so
479 recursion here is needed only for component types. */
480 if (visited
->add (t1
))
482 return odr_types_equivalent_p (t1
, t2
, false, NULL
, visited
);
484 return types_same_for_odr (t1
, t2
);
487 /* Output ODR violation warning about T1 and T2 with REASON.
488 Display location of ST1 and ST2 if REASON speaks about field or
490 If WARN is false, do nothing. Set WARNED if warning was indeed
494 warn_odr (tree t1
, tree t2
, tree st1
, tree st2
,
495 bool warn
, bool *warned
, const char *reason
)
497 tree decl2
= TYPE_NAME (t2
);
501 if (!warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (t1
)), OPT_Wodr
,
502 "type %qT violates one definition rule",
507 else if (TREE_CODE (st1
) == FIELD_DECL
)
509 inform (DECL_SOURCE_LOCATION (decl2
),
510 "a different type is defined in another translation unit");
511 inform (DECL_SOURCE_LOCATION (st1
),
512 "the first difference of corresponding definitions is field %qD",
516 else if (TREE_CODE (st1
) == FUNCTION_DECL
)
518 inform (DECL_SOURCE_LOCATION (decl2
),
519 "a different type is defined in another translation unit");
520 inform (DECL_SOURCE_LOCATION (st1
),
521 "the first difference of corresponding definitions is method %qD",
527 inform (DECL_SOURCE_LOCATION (decl2
), reason
);
533 /* We already warned about ODR mismatch. T1 and T2 ought to be equivalent
534 because they are used on same place in ODR matching types.
535 They are not; inform the user. */
538 warn_types_mismatch (tree t1
, tree t2
)
540 if (!TYPE_NAME (t1
) || !TYPE_NAME (t2
))
542 /* In Firefox it is a common bug to have same types but in
543 different namespaces. Be a bit more informative on
545 if (TYPE_CONTEXT (t1
) && TYPE_CONTEXT (t2
)
546 && (((TREE_CODE (TYPE_CONTEXT (t1
)) == NAMESPACE_DECL
)
547 != (TREE_CODE (TYPE_CONTEXT (t2
)) == NAMESPACE_DECL
))
548 || (TREE_CODE (TYPE_CONTEXT (t1
)) == NAMESPACE_DECL
549 && (DECL_NAME (TYPE_CONTEXT (t1
)) !=
550 DECL_NAME (TYPE_CONTEXT (t2
))))))
551 inform (DECL_SOURCE_LOCATION (TYPE_NAME (t1
)),
552 "type %qT should match type %qT but is defined "
553 "in different namespace ",
556 inform (DECL_SOURCE_LOCATION (TYPE_NAME (t1
)),
557 "type %qT should match type %qT",
559 inform (DECL_SOURCE_LOCATION (TYPE_NAME (t2
)),
560 "the incompatible type is defined here");
563 /* Compare T1 and T2, report ODR violations if WARN is true and set
564 WARNED to true if anything is reported. Return true if types match.
565 If true is returned, the types are also compatible in the sense of
566 gimple_canonical_types_compatible_p. */
569 odr_types_equivalent_p (tree t1
, tree t2
, bool warn
, bool *warned
, hash_set
<tree
> *visited
)
571 /* Check first for the obvious case of pointer identity. */
574 gcc_assert (!type_in_anonymous_namespace_p (t1
));
575 gcc_assert (!type_in_anonymous_namespace_p (t2
));
577 /* Can't be the same type if the types don't have the same code. */
578 if (TREE_CODE (t1
) != TREE_CODE (t2
))
580 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
581 G_("a different type is defined in another translation unit"));
585 if (TYPE_QUALS (t1
) != TYPE_QUALS (t2
))
587 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
588 G_("a type with different qualifiers is defined in another "
589 "translation unit"));
593 if (comp_type_attributes (t1
, t2
) != 1)
595 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
596 G_("a type with attributes "
597 "is defined in another translation unit"));
601 if (TREE_CODE (t1
) == ENUMERAL_TYPE
)
604 for (v1
= TYPE_VALUES (t1
), v2
= TYPE_VALUES (t2
);
605 v1
&& v2
; v1
= TREE_CHAIN (v1
), v2
= TREE_CHAIN (v2
))
607 if (TREE_PURPOSE (v1
) != TREE_PURPOSE (v2
))
609 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
610 G_("an enum with different value name"
611 " is defined in another translation unit"));
614 if (TREE_VALUE (v1
) != TREE_VALUE (v2
)
615 && !operand_equal_p (DECL_INITIAL (TREE_VALUE (v1
)),
616 DECL_INITIAL (TREE_VALUE (v2
)), 0))
618 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
619 G_("an enum with different values is defined"
620 " in another translation unit"));
626 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
627 G_("an enum with mismatching number of values "
628 "is defined in another translation unit"));
633 /* Non-aggregate types can be handled cheaply. */
634 if (INTEGRAL_TYPE_P (t1
)
635 || SCALAR_FLOAT_TYPE_P (t1
)
636 || FIXED_POINT_TYPE_P (t1
)
637 || TREE_CODE (t1
) == VECTOR_TYPE
638 || TREE_CODE (t1
) == COMPLEX_TYPE
639 || TREE_CODE (t1
) == OFFSET_TYPE
640 || POINTER_TYPE_P (t1
))
642 if (TYPE_PRECISION (t1
) != TYPE_PRECISION (t2
))
644 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
645 G_("a type with different precision is defined "
646 "in another translation unit"));
649 if (TYPE_UNSIGNED (t1
) != TYPE_UNSIGNED (t2
))
651 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
652 G_("a type with different signedness is defined "
653 "in another translation unit"));
657 if (TREE_CODE (t1
) == INTEGER_TYPE
658 && TYPE_STRING_FLAG (t1
) != TYPE_STRING_FLAG (t2
))
660 /* char WRT uint_8? */
661 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
662 G_("a different type is defined in another "
663 "translation unit"));
667 /* For canonical type comparisons we do not want to build SCCs
668 so we cannot compare pointed-to types. But we can, for now,
669 require the same pointed-to type kind and match what
670 useless_type_conversion_p would do. */
671 if (POINTER_TYPE_P (t1
))
673 if (TYPE_ADDR_SPACE (TREE_TYPE (t1
))
674 != TYPE_ADDR_SPACE (TREE_TYPE (t2
)))
676 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
677 G_("it is defined as a pointer in different address "
678 "space in another translation unit"));
682 if (!odr_subtypes_equivalent_p (TREE_TYPE (t1
), TREE_TYPE (t2
), visited
))
684 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
685 G_("it is defined as a pointer to different type "
686 "in another translation unit"));
688 warn_types_mismatch (TREE_TYPE (t1
), TREE_TYPE (t2
));
693 /* Tail-recurse to components. */
694 if ((TREE_CODE (t1
) == VECTOR_TYPE
|| TREE_CODE (t1
) == COMPLEX_TYPE
)
695 && !odr_subtypes_equivalent_p (TREE_TYPE (t1
), TREE_TYPE (t2
), visited
))
697 /* Probably specific enough. */
698 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
699 G_("a different type is defined "
700 "in another translation unit"));
702 warn_types_mismatch (TREE_TYPE (t1
), TREE_TYPE (t2
));
706 gcc_assert (operand_equal_p (TYPE_SIZE (t1
), TYPE_SIZE (t2
), 0));
707 gcc_assert (operand_equal_p (TYPE_SIZE_UNIT (t1
),
708 TYPE_SIZE_UNIT (t2
), 0));
709 gcc_assert (TYPE_MODE (t1
) == TYPE_MODE (t2
));
714 /* Do type-specific comparisons. */
715 switch (TREE_CODE (t1
))
719 /* Array types are the same if the element types are the same and
720 the number of elements are the same. */
721 if (!odr_subtypes_equivalent_p (TREE_TYPE (t1
), TREE_TYPE (t2
), visited
))
723 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
724 G_("a different type is defined in another "
725 "translation unit"));
727 warn_types_mismatch (TREE_TYPE (t1
), TREE_TYPE (t2
));
729 gcc_assert (TYPE_STRING_FLAG (t1
) == TYPE_STRING_FLAG (t2
));
730 gcc_assert (TYPE_NONALIASED_COMPONENT (t1
)
731 == TYPE_NONALIASED_COMPONENT (t2
));
733 tree i1
= TYPE_DOMAIN (t1
);
734 tree i2
= TYPE_DOMAIN (t2
);
736 /* For an incomplete external array, the type domain can be
737 NULL_TREE. Check this condition also. */
738 if (i1
== NULL_TREE
|| i2
== NULL_TREE
)
741 tree min1
= TYPE_MIN_VALUE (i1
);
742 tree min2
= TYPE_MIN_VALUE (i2
);
743 tree max1
= TYPE_MAX_VALUE (i1
);
744 tree max2
= TYPE_MAX_VALUE (i2
);
746 /* In C++, minimums should be always 0. */
747 gcc_assert (min1
== min2
);
748 if (!operand_equal_p (max1
, max2
, 0))
750 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
751 G_("an array of different size is defined "
752 "in another translation unit"));
755 gcc_assert (operand_equal_p (TYPE_SIZE (t1
), TYPE_SIZE (t2
), 0));
756 gcc_assert (operand_equal_p (TYPE_SIZE_UNIT (t1
),
757 TYPE_SIZE_UNIT (t2
), 0));
763 /* Function types are the same if the return type and arguments types
765 if (!odr_subtypes_equivalent_p (TREE_TYPE (t1
), TREE_TYPE (t2
), visited
))
767 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
768 G_("has different return value "
769 "in another translation unit"));
771 warn_types_mismatch (TREE_TYPE (t1
), TREE_TYPE (t2
));
775 if (TYPE_ARG_TYPES (t1
) == TYPE_ARG_TYPES (t2
))
781 for (parms1
= TYPE_ARG_TYPES (t1
), parms2
= TYPE_ARG_TYPES (t2
);
783 parms1
= TREE_CHAIN (parms1
), parms2
= TREE_CHAIN (parms2
))
785 if (!odr_subtypes_equivalent_p
786 (TREE_VALUE (parms1
), TREE_VALUE (parms2
), visited
))
788 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
789 G_("has different parameters in another "
790 "translation unit"));
792 warn_types_mismatch (TREE_VALUE (parms1
),
793 TREE_VALUE (parms2
));
798 if (parms1
|| parms2
)
800 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
801 G_("has different parameters "
802 "in another translation unit"));
811 case QUAL_UNION_TYPE
:
815 /* For aggregate types, all the fields must be the same. */
816 if (COMPLETE_TYPE_P (t1
) && COMPLETE_TYPE_P (t2
))
818 for (f1
= TYPE_FIELDS (t1
), f2
= TYPE_FIELDS (t2
);
820 f1
= TREE_CHAIN (f1
), f2
= TREE_CHAIN (f2
))
822 /* Skip non-fields. */
823 while (f1
&& TREE_CODE (f1
) != FIELD_DECL
)
824 f1
= TREE_CHAIN (f1
);
825 while (f2
&& TREE_CODE (f2
) != FIELD_DECL
)
826 f2
= TREE_CHAIN (f2
);
829 if (DECL_ARTIFICIAL (f1
) != DECL_ARTIFICIAL (f2
))
831 if (DECL_NAME (f1
) != DECL_NAME (f2
)
832 && !DECL_ARTIFICIAL (f1
))
834 warn_odr (t1
, t2
, f1
, f2
, warn
, warned
,
835 G_("a field with different name is defined "
836 "in another translation unit"));
839 if (!odr_subtypes_equivalent_p (TREE_TYPE (f1
), TREE_TYPE (f2
), visited
))
841 /* Do not warn about artificial fields and just go into generic
842 field mismatch warning. */
843 if (DECL_ARTIFICIAL (f1
))
846 warn_odr (t1
, t2
, f1
, f2
, warn
, warned
,
847 G_("a field of same name but different type "
848 "is defined in another translation unit"));
850 warn_types_mismatch (TREE_TYPE (f1
), TREE_TYPE (f2
));
853 if (!gimple_compare_field_offset (f1
, f2
))
855 /* Do not warn about artificial fields and just go into generic
856 field mismatch warning. */
857 if (DECL_ARTIFICIAL (f1
))
859 warn_odr (t1
, t2
, t1
, t2
, warn
, warned
,
860 G_("fields has different layout "
861 "in another translation unit"));
864 gcc_assert (DECL_NONADDRESSABLE_P (f1
)
865 == DECL_NONADDRESSABLE_P (f2
));
868 /* If one aggregate has more fields than the other, they
872 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
873 G_("a type with different number of fields "
874 "is defined in another translation unit"));
877 if ((TYPE_MAIN_VARIANT (t1
) == t1
|| TYPE_MAIN_VARIANT (t2
) == t2
)
878 && (TYPE_METHODS (TYPE_MAIN_VARIANT (t1
))
879 != TYPE_METHODS (TYPE_MAIN_VARIANT (t2
))))
881 for (f1
= TYPE_METHODS (TYPE_MAIN_VARIANT (t1
)),
882 f2
= TYPE_METHODS (TYPE_MAIN_VARIANT (t2
));
883 f1
&& f2
; f1
= DECL_CHAIN (f1
), f2
= DECL_CHAIN (f2
))
885 if (DECL_ASSEMBLER_NAME (f1
) != DECL_ASSEMBLER_NAME (f2
))
887 warn_odr (t1
, t2
, f1
, f2
, warn
, warned
,
888 G_("a different method of same type "
889 "is defined in another translation unit"));
892 if (DECL_VIRTUAL_P (f1
) != DECL_VIRTUAL_P (f2
))
894 warn_odr (t1
, t2
, f1
, f2
, warn
, warned
,
895 G_("s definition that differs by virtual "
896 "keyword in another translation unit"));
899 if (DECL_VINDEX (f1
) != DECL_VINDEX (f2
))
901 warn_odr (t1
, t2
, f1
, f2
, warn
, warned
,
902 G_("virtual table layout differs in another "
903 "translation unit"));
906 if (odr_subtypes_equivalent_p (TREE_TYPE (f1
), TREE_TYPE (f2
), visited
))
908 warn_odr (t1
, t2
, f1
, f2
, warn
, warned
,
909 G_("method with incompatible type is defined "
910 "in another translation unit"));
916 warn_odr (t1
, t2
, NULL
, NULL
, warn
, warned
,
917 G_("a type with different number of methods "
918 "is defined in another translation unit"));
922 gcc_assert (operand_equal_p (TYPE_SIZE (t1
), TYPE_SIZE (t2
), 0));
923 gcc_assert (operand_equal_p (TYPE_SIZE_UNIT (t1
),
924 TYPE_SIZE_UNIT (t2
), 0));
935 /* TYPE is equivalent to VAL by ODR, but its tree representation differs
936 from VAL->type. This may happen in LTO where tree merging did not merge
937 all variants of the same type. It may or may not mean the ODR violation.
938 Add it to the list of duplicates and warn on some violations. */
941 add_type_duplicate (odr_type val
, tree type
)
943 bool build_bases
= false;
945 val
->types_set
= new hash_set
<tree
>;
947 /* Always prefer complete type to be the leader. */
948 if (!COMPLETE_TYPE_P (val
->type
)
949 && COMPLETE_TYPE_P (type
))
958 /* See if this duplicate is new. */
959 if (!val
->types_set
->add (type
))
962 bool base_mismatch
= false;
965 hash_set
<tree
> visited
;
967 gcc_assert (in_lto_p
);
968 vec_safe_push (val
->types
, type
);
970 /* First we compare memory layout. */
971 if (!odr_types_equivalent_p (val
->type
, type
, !flag_ltrans
&& !val
->odr_violated
,
975 odr_violation_reported
= true;
976 val
->odr_violated
= true;
977 if (cgraph_dump_file
)
979 fprintf (cgraph_dump_file
, "ODR violation\n");
981 print_node (cgraph_dump_file
, "", val
->type
, 0);
982 putc ('\n',cgraph_dump_file
);
983 print_node (cgraph_dump_file
, "", type
, 0);
984 putc ('\n',cgraph_dump_file
);
988 /* Next sanity check that bases are the same. If not, we will end
989 up producing wrong answers. */
990 if (COMPLETE_TYPE_P (type
) && COMPLETE_TYPE_P (val
->type
)
991 && TREE_CODE (val
->type
) == RECORD_TYPE
992 && TREE_CODE (type
) == RECORD_TYPE
993 && TYPE_BINFO (val
->type
) && TYPE_BINFO (type
))
995 for (j
= 0, i
= 0; i
< BINFO_N_BASE_BINFOS (TYPE_BINFO (type
)); i
++)
996 if (polymorphic_type_binfo_p (BINFO_BASE_BINFO (TYPE_BINFO (type
), i
)))
998 odr_type base
= get_odr_type
1000 (BINFO_BASE_BINFO (TYPE_BINFO (type
),
1003 if (val
->bases
.length () <= j
|| val
->bases
[j
] != base
)
1004 base_mismatch
= true;
1010 odr_violation_reported
= true;
1012 if (!warned
&& !val
->odr_violated
)
1013 warn_odr (type
, val
->type
, NULL
, NULL
, !warned
, &warned
,
1014 "a type with the same name but different bases is "
1015 "defined in another translation unit");
1016 val
->odr_violated
= true;
1017 if (cgraph_dump_file
)
1019 fprintf (cgraph_dump_file
, "ODR bse violation or merging bug?\n");
1021 print_node (cgraph_dump_file
, "", val
->type
, 0);
1022 putc ('\n',cgraph_dump_file
);
1023 print_node (cgraph_dump_file
, "", type
, 0);
1024 putc ('\n',cgraph_dump_file
);
1029 /* Regularize things a little. During LTO same types may come with
1030 different BINFOs. Either because their virtual table was
1031 not merged by tree merging and only later at decl merging or
1032 because one type comes with external vtable, while other
1033 with internal. We want to merge equivalent binfos to conserve
1034 memory and streaming overhead.
1036 The external vtables are more harmful: they contain references
1037 to external declarations of methods that may be defined in the
1038 merged LTO unit. For this reason we absolutely need to remove
1039 them and replace by internal variants. Not doing so will lead
1040 to incomplete answers from possible_polymorphic_call_targets. */
1041 if (!flag_ltrans
&& merge
1042 && TREE_CODE (val
->type
) == RECORD_TYPE
1043 && TREE_CODE (type
) == RECORD_TYPE
1044 && TYPE_BINFO (val
->type
) && TYPE_BINFO (type
)
1045 && TYPE_MAIN_VARIANT (type
) == type
1046 && TYPE_MAIN_VARIANT (val
->type
) == val
->type
1047 && BINFO_VTABLE (TYPE_BINFO (val
->type
))
1048 && BINFO_VTABLE (TYPE_BINFO (type
)))
1050 tree master_binfo
= TYPE_BINFO (val
->type
);
1051 tree v1
= BINFO_VTABLE (master_binfo
);
1052 tree v2
= BINFO_VTABLE (TYPE_BINFO (type
));
1054 if (TREE_CODE (v1
) == POINTER_PLUS_EXPR
)
1056 gcc_assert (TREE_CODE (v2
) == POINTER_PLUS_EXPR
1057 && operand_equal_p (TREE_OPERAND (v1
, 1),
1058 TREE_OPERAND (v2
, 1), 0));
1059 v1
= TREE_OPERAND (TREE_OPERAND (v1
, 0), 0);
1060 v2
= TREE_OPERAND (TREE_OPERAND (v2
, 0), 0);
1062 gcc_assert (DECL_ASSEMBLER_NAME (v1
)
1063 == DECL_ASSEMBLER_NAME (v2
));
1065 if (DECL_EXTERNAL (v1
) && !DECL_EXTERNAL (v2
))
1069 set_type_binfo (val
->type
, TYPE_BINFO (type
));
1070 for (i
= 0; i
< val
->types
->length (); i
++)
1072 if (TYPE_BINFO ((*val
->types
)[i
])
1074 set_type_binfo ((*val
->types
)[i
], TYPE_BINFO (type
));
1076 BINFO_TYPE (TYPE_BINFO (type
)) = val
->type
;
1079 set_type_binfo (type
, master_binfo
);
1085 /* Get ODR type hash entry for TYPE. If INSERT is true, create
1086 possibly new entry. */
1089 get_odr_type (tree type
, bool insert
)
1094 bool build_bases
= false;
1095 bool insert_to_odr_array
= false;
1098 type
= main_odr_variant (type
);
1100 hash
= hash_type_name (type
);
1102 = odr_hash
->find_slot_with_hash (type
, hash
, insert
? INSERT
: NO_INSERT
);
1106 /* See if we already have entry for type. */
1111 /* With LTO we need to support multiple tree representation of
1112 the same ODR type. */
1113 if (val
->type
!= type
)
1114 build_bases
= add_type_duplicate (val
, type
);
1118 val
= ggc_cleared_alloc
<odr_type_d
> ();
1121 val
->derived_types
= vNULL
;
1122 val
->anonymous_namespace
= type_in_anonymous_namespace_p (type
);
1123 build_bases
= COMPLETE_TYPE_P (val
->type
);
1124 insert_to_odr_array
= true;
1127 if (build_bases
&& TREE_CODE (type
) == RECORD_TYPE
&& TYPE_BINFO (type
)
1128 && type
== TYPE_MAIN_VARIANT (type
))
1130 tree binfo
= TYPE_BINFO (type
);
1133 gcc_assert (BINFO_TYPE (TYPE_BINFO (val
->type
)) = type
);
1135 val
->all_derivations_known
= type_all_derivations_known_p (type
);
1137 for (i
= 0; i
< BINFO_N_BASE_BINFOS (binfo
); i
++)
1138 /* For now record only polymorphic types. other are
1139 pointless for devirtualization and we can not precisely
1140 determine ODR equivalency of these during LTO. */
1141 if (polymorphic_type_binfo_p (BINFO_BASE_BINFO (binfo
, i
)))
1143 odr_type base
= get_odr_type (BINFO_TYPE (BINFO_BASE_BINFO (binfo
,
1146 gcc_assert (TYPE_MAIN_VARIANT (base
->type
) == base
->type
);
1147 base
->derived_types
.safe_push (val
);
1148 val
->bases
.safe_push (base
);
1149 if (base
->id
> base_id
)
1153 /* Ensure that type always appears after bases. */
1154 if (insert_to_odr_array
)
1157 val
->id
= odr_types
.length ();
1158 vec_safe_push (odr_types_ptr
, val
);
1160 else if (base_id
> val
->id
)
1162 odr_types
[val
->id
] = 0;
1163 /* Be sure we did not recorded any derived types; these may need
1165 gcc_assert (val
->derived_types
.length() == 0);
1167 val
->id
= odr_types
.length ();
1168 vec_safe_push (odr_types_ptr
, val
);
1173 /* Dump ODR type T and all its derrived type. INDENT specify indentation for
1174 recusive printing. */
1177 dump_odr_type (FILE *f
, odr_type t
, int indent
=0)
1180 fprintf (f
, "%*s type %i: ", indent
* 2, "", t
->id
);
1181 print_generic_expr (f
, t
->type
, TDF_SLIM
);
1182 fprintf (f
, "%s", t
->anonymous_namespace
? " (anonymous namespace)":"");
1183 fprintf (f
, "%s\n", t
->all_derivations_known
? " (derivations known)":"");
1184 if (TYPE_NAME (t
->type
))
1186 fprintf (f
, "%*s defined at: %s:%i\n", indent
* 2, "",
1187 DECL_SOURCE_FILE (TYPE_NAME (t
->type
)),
1188 DECL_SOURCE_LINE (TYPE_NAME (t
->type
)));
1190 if (t
->bases
.length ())
1192 fprintf (f
, "%*s base odr type ids: ", indent
* 2, "");
1193 for (i
= 0; i
< t
->bases
.length (); i
++)
1194 fprintf (f
, " %i", t
->bases
[i
]->id
);
1197 if (t
->derived_types
.length ())
1199 fprintf (f
, "%*s derived types:\n", indent
* 2, "");
1200 for (i
= 0; i
< t
->derived_types
.length (); i
++)
1201 dump_odr_type (f
, t
->derived_types
[i
], indent
+ 1);
1206 /* Dump the type inheritance graph. */
1209 dump_type_inheritance_graph (FILE *f
)
1214 fprintf (f
, "\n\nType inheritance graph:\n");
1215 for (i
= 0; i
< odr_types
.length (); i
++)
1217 if (odr_types
[i
] && odr_types
[i
]->bases
.length () == 0)
1218 dump_odr_type (f
, odr_types
[i
]);
1220 for (i
= 0; i
< odr_types
.length (); i
++)
1222 if (odr_types
[i
] && odr_types
[i
]->types
&& odr_types
[i
]->types
->length ())
1225 fprintf (f
, "Duplicate tree types for odr type %i\n", i
);
1226 print_node (f
, "", odr_types
[i
]->type
, 0);
1227 for (j
= 0; j
< odr_types
[i
]->types
->length (); j
++)
1230 fprintf (f
, "duplicate #%i\n", j
);
1231 print_node (f
, "", (*odr_types
[i
]->types
)[j
], 0);
1232 t
= (*odr_types
[i
]->types
)[j
];
1233 while (TYPE_P (t
) && TYPE_CONTEXT (t
))
1235 t
= TYPE_CONTEXT (t
);
1236 print_node (f
, "", t
, 0);
1244 /* Given method type T, return type of class it belongs to.
1245 Lookup this pointer and get its type. */
1248 method_class_type (const_tree t
)
1250 tree first_parm_type
= TREE_VALUE (TYPE_ARG_TYPES (t
));
1251 gcc_assert (TREE_CODE (t
) == METHOD_TYPE
);
1253 return TREE_TYPE (first_parm_type
);
1256 /* Initialize IPA devirt and build inheritance tree graph. */
1259 build_type_inheritance_graph (void)
1261 struct symtab_node
*n
;
1262 FILE *inheritance_dump_file
;
1267 timevar_push (TV_IPA_INHERITANCE
);
1268 inheritance_dump_file
= dump_begin (TDI_inheritance
, &flags
);
1269 odr_hash
= new odr_hash_type (23);
1271 /* We reconstruct the graph starting of types of all methods seen in the
1274 if (is_a
<cgraph_node
*> (n
)
1275 && DECL_VIRTUAL_P (n
->decl
)
1276 && n
->real_symbol_p ())
1277 get_odr_type (TYPE_MAIN_VARIANT (method_class_type (TREE_TYPE (n
->decl
))),
1280 /* Look also for virtual tables of types that do not define any methods.
1282 We need it in a case where class B has virtual base of class A
1283 re-defining its virtual method and there is class C with no virtual
1284 methods with B as virtual base.
1286 Here we output B's virtual method in two variant - for non-virtual
1287 and virtual inheritance. B's virtual table has non-virtual version,
1288 while C's has virtual.
1290 For this reason we need to know about C in order to include both
1291 variants of B. More correctly, record_target_from_binfo should
1292 add both variants of the method when walking B, but we have no
1293 link in between them.
1295 We rely on fact that either the method is exported and thus we
1296 assume it is called externally or C is in anonymous namespace and
1297 thus we will see the vtable. */
1299 else if (is_a
<varpool_node
*> (n
)
1300 && DECL_VIRTUAL_P (n
->decl
)
1301 && TREE_CODE (DECL_CONTEXT (n
->decl
)) == RECORD_TYPE
1302 && TYPE_BINFO (DECL_CONTEXT (n
->decl
))
1303 && polymorphic_type_binfo_p (TYPE_BINFO (DECL_CONTEXT (n
->decl
))))
1304 get_odr_type (TYPE_MAIN_VARIANT (DECL_CONTEXT (n
->decl
)), true);
1305 if (inheritance_dump_file
)
1307 dump_type_inheritance_graph (inheritance_dump_file
);
1308 dump_end (TDI_inheritance
, inheritance_dump_file
);
1310 timevar_pop (TV_IPA_INHERITANCE
);
1313 /* Return true if N has reference from live virtual table
1314 (and thus can be a destination of polymorphic call).
1315 Be conservatively correct when callgraph is not built or
1316 if the method may be referred externally. */
1319 referenced_from_vtable_p (struct cgraph_node
*node
)
1322 struct ipa_ref
*ref
;
1325 if (node
->externally_visible
1326 || node
->used_from_other_partition
)
1329 /* Keep this test constant time.
1330 It is unlikely this can happen except for the case where speculative
1331 devirtualization introduced many speculative edges to this node.
1332 In this case the target is very likely alive anyway. */
1333 if (node
->ref_list
.referring
.length () > 100)
1336 /* We need references built. */
1337 if (cgraph_state
<= CGRAPH_STATE_CONSTRUCTION
)
1340 for (i
= 0; node
->iterate_referring (i
, ref
); i
++)
1342 if ((ref
->use
== IPA_REF_ALIAS
1343 && referenced_from_vtable_p (dyn_cast
<cgraph_node
*> (ref
->referring
)))
1344 || (ref
->use
== IPA_REF_ADDR
1345 && TREE_CODE (ref
->referring
->decl
) == VAR_DECL
1346 && DECL_VIRTUAL_P (ref
->referring
->decl
)))
1354 /* If TARGET has associated node, record it in the NODES array.
1355 CAN_REFER specify if program can refer to the target directly.
1356 if TARGET is unknown (NULL) or it can not be inserted (for example because
1357 its body was already removed and there is no way to refer to it), clear
1361 maybe_record_node (vec
<cgraph_node
*> &nodes
,
1362 tree target
, hash_set
<tree
> *inserted
,
1366 struct cgraph_node
*target_node
, *alias_target
;
1367 enum availability avail
;
1369 /* cxa_pure_virtual and __builtin_unreachable do not need to be added into
1370 list of targets; the runtime effect of calling them is undefined.
1371 Only "real" virtual methods should be accounted. */
1372 if (target
&& TREE_CODE (TREE_TYPE (target
)) != METHOD_TYPE
)
1377 /* The only case when method of anonymous namespace becomes unreferable
1378 is when we completely optimized it out. */
1381 || !type_in_anonymous_namespace_p (DECL_CONTEXT (target
)))
1389 target_node
= cgraph_node::get (target
);
1391 /* Preffer alias target over aliases, so we do not get confused by
1395 alias_target
= target_node
->ultimate_alias_target (&avail
);
1396 if (target_node
!= alias_target
1397 && avail
>= AVAIL_AVAILABLE
1398 && target_node
->get_availability ())
1399 target_node
= alias_target
;
1402 /* Method can only be called by polymorphic call if any
1403 of vtables refering to it are alive.
1405 While this holds for non-anonymous functions, too, there are
1406 cases where we want to keep them in the list; for example
1407 inline functions with -fno-weak are static, but we still
1408 may devirtualize them when instance comes from other unit.
1409 The same holds for LTO.
1411 Currently we ignore these functions in speculative devirtualization.
1412 ??? Maybe it would make sense to be more aggressive for LTO even
1415 && type_in_anonymous_namespace_p (DECL_CONTEXT (target
))
1417 || !referenced_from_vtable_p (target_node
)))
1419 /* See if TARGET is useful function we can deal with. */
1420 else if (target_node
!= NULL
1421 && (TREE_PUBLIC (target
)
1422 || DECL_EXTERNAL (target
)
1423 || target_node
->definition
)
1424 && target_node
->real_symbol_p ())
1426 gcc_assert (!target_node
->global
.inlined_to
);
1427 gcc_assert (target_node
->real_symbol_p ());
1428 if (!inserted
->add (target
))
1430 cached_polymorphic_call_targets
->add (target_node
);
1431 nodes
.safe_push (target_node
);
1435 && (!type_in_anonymous_namespace_p
1436 (DECL_CONTEXT (target
))
1441 /* See if BINFO's type match OUTER_TYPE. If so, lookup
1442 BINFO of subtype of OTR_TYPE at OFFSET and in that BINFO find
1443 method in vtable and insert method to NODES array
1444 or BASES_TO_CONSIDER if this array is non-NULL.
1445 Otherwise recurse to base BINFOs.
1446 This match what get_binfo_at_offset does, but with offset
1449 TYPE_BINFOS is a stack of BINFOS of types with defined
1450 virtual table seen on way from class type to BINFO.
1452 MATCHED_VTABLES tracks virtual tables we already did lookup
1453 for virtual function in. INSERTED tracks nodes we already
1456 ANONYMOUS is true if BINFO is part of anonymous namespace.
1458 Clear COMPLETEP when we hit unreferable target.
1462 record_target_from_binfo (vec
<cgraph_node
*> &nodes
,
1463 vec
<tree
> *bases_to_consider
,
1466 vec
<tree
> &type_binfos
,
1467 HOST_WIDE_INT otr_token
,
1469 HOST_WIDE_INT offset
,
1470 hash_set
<tree
> *inserted
,
1471 hash_set
<tree
> *matched_vtables
,
1475 tree type
= BINFO_TYPE (binfo
);
1480 if (BINFO_VTABLE (binfo
))
1481 type_binfos
.safe_push (binfo
);
1482 if (types_same_for_odr (type
, outer_type
))
1485 tree type_binfo
= NULL
;
1487 /* Lookup BINFO with virtual table. For normal types it is always last
1489 for (i
= type_binfos
.length () - 1; i
>= 0; i
--)
1490 if (BINFO_OFFSET (type_binfos
[i
]) == BINFO_OFFSET (binfo
))
1492 type_binfo
= type_binfos
[i
];
1495 if (BINFO_VTABLE (binfo
))
1497 /* If this is duplicated BINFO for base shared by virtual inheritance,
1498 we may not have its associated vtable. This is not a problem, since
1499 we will walk it on the other path. */
1502 tree inner_binfo
= get_binfo_at_offset (type_binfo
,
1506 gcc_assert (odr_violation_reported
);
1509 /* For types in anonymous namespace first check if the respective vtable
1510 is alive. If not, we know the type can't be called. */
1511 if (!flag_ltrans
&& anonymous
)
1513 tree vtable
= BINFO_VTABLE (inner_binfo
);
1514 varpool_node
*vnode
;
1516 if (TREE_CODE (vtable
) == POINTER_PLUS_EXPR
)
1517 vtable
= TREE_OPERAND (TREE_OPERAND (vtable
, 0), 0);
1518 vnode
= varpool_node::get (vtable
);
1519 if (!vnode
|| !vnode
->definition
)
1522 gcc_assert (inner_binfo
);
1523 if (bases_to_consider
1524 ? !matched_vtables
->contains (BINFO_VTABLE (inner_binfo
))
1525 : !matched_vtables
->add (BINFO_VTABLE (inner_binfo
)))
1528 tree target
= gimple_get_virt_method_for_binfo (otr_token
,
1531 if (!bases_to_consider
)
1532 maybe_record_node (nodes
, target
, inserted
, can_refer
, completep
);
1533 /* Destructors are never called via construction vtables. */
1534 else if (!target
|| !DECL_CXX_DESTRUCTOR_P (target
))
1535 bases_to_consider
->safe_push (target
);
1541 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1542 /* Walking bases that have no virtual method is pointless excercise. */
1543 if (polymorphic_type_binfo_p (base_binfo
))
1544 record_target_from_binfo (nodes
, bases_to_consider
, base_binfo
, otr_type
,
1546 otr_token
, outer_type
, offset
, inserted
,
1547 matched_vtables
, anonymous
, completep
);
1548 if (BINFO_VTABLE (binfo
))
1552 /* Lookup virtual methods matching OTR_TYPE (with OFFSET and OTR_TOKEN)
1553 of TYPE, insert them to NODES, recurse into derived nodes.
1554 INSERTED is used to avoid duplicate insertions of methods into NODES.
1555 MATCHED_VTABLES are used to avoid duplicate walking vtables.
1556 Clear COMPLETEP if unreferable target is found.
1558 If CONSIDER_CONSTURCTION is true, record to BASES_TO_CONSDIER
1559 all cases where BASE_SKIPPED is true (because the base is abstract
1563 possible_polymorphic_call_targets_1 (vec
<cgraph_node
*> &nodes
,
1564 hash_set
<tree
> *inserted
,
1565 hash_set
<tree
> *matched_vtables
,
1568 HOST_WIDE_INT otr_token
,
1570 HOST_WIDE_INT offset
,
1572 vec
<tree
> &bases_to_consider
,
1573 bool consider_construction
)
1575 tree binfo
= TYPE_BINFO (type
->type
);
1577 vec
<tree
> type_binfos
= vNULL
;
1578 bool possibly_instantiated
= type_possibly_instantiated_p (type
->type
);
1580 /* We may need to consider types w/o instances because of possible derived
1581 types using their methods either directly or via construction vtables.
1582 We are safe to skip them when all derivations are known, since we will
1584 This is done by recording them to BASES_TO_CONSIDER array. */
1585 if (possibly_instantiated
|| consider_construction
)
1587 record_target_from_binfo (nodes
,
1588 (!possibly_instantiated
1589 && type_all_derivations_known_p (type
->type
))
1590 ? &bases_to_consider
: NULL
,
1591 binfo
, otr_type
, type_binfos
, otr_token
,
1593 inserted
, matched_vtables
,
1594 type
->anonymous_namespace
, completep
);
1596 type_binfos
.release ();
1597 for (i
= 0; i
< type
->derived_types
.length (); i
++)
1598 possible_polymorphic_call_targets_1 (nodes
, inserted
,
1601 type
->derived_types
[i
],
1602 otr_token
, outer_type
, offset
, completep
,
1603 bases_to_consider
, consider_construction
);
1606 /* Cache of queries for polymorphic call targets.
1608 Enumerating all call targets may get expensive when there are many
1609 polymorphic calls in the program, so we memoize all the previous
1610 queries and avoid duplicated work. */
1612 struct polymorphic_call_target_d
1614 HOST_WIDE_INT otr_token
;
1615 ipa_polymorphic_call_context context
;
1617 vec
<cgraph_node
*> targets
;
1618 int speculative_targets
;
1624 /* Polymorphic call target cache helpers. */
1626 struct polymorphic_call_target_hasher
1628 typedef polymorphic_call_target_d value_type
;
1629 typedef polymorphic_call_target_d compare_type
;
1630 static inline hashval_t
hash (const value_type
*);
1631 static inline bool equal (const value_type
*, const compare_type
*);
1632 static inline void remove (value_type
*);
1635 /* Return the computed hashcode for ODR_QUERY. */
1638 polymorphic_call_target_hasher::hash (const value_type
*odr_query
)
1640 inchash::hash
hstate (odr_query
->otr_token
);
1642 hstate
.add_wide_int (odr_query
->type
->id
);
1643 hstate
.merge_hash (TYPE_UID (odr_query
->context
.outer_type
));
1644 hstate
.add_wide_int (odr_query
->context
.offset
);
1646 if (odr_query
->context
.speculative_outer_type
)
1648 hstate
.merge_hash (TYPE_UID (odr_query
->context
.speculative_outer_type
));
1649 hstate
.add_wide_int (odr_query
->context
.speculative_offset
);
1651 hstate
.add_flag (odr_query
->context
.maybe_in_construction
);
1652 hstate
.add_flag (odr_query
->context
.maybe_derived_type
);
1653 hstate
.add_flag (odr_query
->context
.speculative_maybe_derived_type
);
1654 hstate
.commit_flag ();
1655 return hstate
.end ();
1658 /* Compare cache entries T1 and T2. */
1661 polymorphic_call_target_hasher::equal (const value_type
*t1
,
1662 const compare_type
*t2
)
1664 return (t1
->type
== t2
->type
&& t1
->otr_token
== t2
->otr_token
1665 && t1
->context
.offset
== t2
->context
.offset
1666 && t1
->context
.speculative_offset
== t2
->context
.speculative_offset
1667 && t1
->context
.outer_type
== t2
->context
.outer_type
1668 && t1
->context
.speculative_outer_type
== t2
->context
.speculative_outer_type
1669 && t1
->context
.maybe_in_construction
1670 == t2
->context
.maybe_in_construction
1671 && t1
->context
.maybe_derived_type
== t2
->context
.maybe_derived_type
1672 && (t1
->context
.speculative_maybe_derived_type
1673 == t2
->context
.speculative_maybe_derived_type
));
1676 /* Remove entry in polymorphic call target cache hash. */
1679 polymorphic_call_target_hasher::remove (value_type
*v
)
1681 v
->targets
.release ();
1685 /* Polymorphic call target query cache. */
1687 typedef hash_table
<polymorphic_call_target_hasher
>
1688 polymorphic_call_target_hash_type
;
1689 static polymorphic_call_target_hash_type
*polymorphic_call_target_hash
;
1691 /* Destroy polymorphic call target query cache. */
1694 free_polymorphic_call_targets_hash ()
1696 if (cached_polymorphic_call_targets
)
1698 delete polymorphic_call_target_hash
;
1699 polymorphic_call_target_hash
= NULL
;
1700 delete cached_polymorphic_call_targets
;
1701 cached_polymorphic_call_targets
= NULL
;
1705 /* When virtual function is removed, we may need to flush the cache. */
1708 devirt_node_removal_hook (struct cgraph_node
*n
, void *d ATTRIBUTE_UNUSED
)
1710 if (cached_polymorphic_call_targets
1711 && cached_polymorphic_call_targets
->contains (n
))
1712 free_polymorphic_call_targets_hash ();
1715 /* Return true when TYPE contains an polymorphic type and thus is interesting
1716 for devirtualization machinery. */
1719 contains_polymorphic_type_p (const_tree type
)
1721 type
= TYPE_MAIN_VARIANT (type
);
1723 if (RECORD_OR_UNION_TYPE_P (type
))
1725 if (TYPE_BINFO (type
)
1726 && polymorphic_type_binfo_p (TYPE_BINFO (type
)))
1728 for (tree fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
1729 if (TREE_CODE (fld
) == FIELD_DECL
1730 && !DECL_ARTIFICIAL (fld
)
1731 && contains_polymorphic_type_p (TREE_TYPE (fld
)))
1735 if (TREE_CODE (type
) == ARRAY_TYPE
)
1736 return contains_polymorphic_type_p (TREE_TYPE (type
));
1740 /* Clear speculative info from CONTEXT. */
1743 clear_speculation (ipa_polymorphic_call_context
*context
)
1745 context
->speculative_outer_type
= NULL
;
1746 context
->speculative_offset
= 0;
1747 context
->speculative_maybe_derived_type
= false;
1750 /* CONTEXT->OUTER_TYPE is a type of memory object where object of EXPECTED_TYPE
1751 is contained at CONTEXT->OFFSET. Walk the memory representation of
1752 CONTEXT->OUTER_TYPE and find the outermost class type that match
1753 EXPECTED_TYPE or contain EXPECTED_TYPE as a base. Update CONTEXT
1756 For example when CONTEXT represents type
1762 and we look for type at offset sizeof(int), we end up with B and offset 0.
1763 If the same is produced by multiple inheritance, we end up with A and offset
1766 If we can not find corresponding class, give up by setting
1767 CONTEXT->OUTER_TYPE to EXPECTED_TYPE and CONTEXT->OFFSET to NULL.
1768 Return true when lookup was sucesful. */
1771 get_class_context (ipa_polymorphic_call_context
*context
,
1774 tree type
= context
->outer_type
;
1775 HOST_WIDE_INT offset
= context
->offset
;
1776 bool speculative
= false;
1777 bool speculation_valid
= false;
1780 if (!context
->outer_type
)
1782 type
= context
->outer_type
= expected_type
;
1783 context
->offset
= offset
= 0;
1786 if (context
->speculative_outer_type
== context
->outer_type
1787 && (!context
->maybe_derived_type
1788 || context
->speculative_maybe_derived_type
))
1790 context
->speculative_outer_type
= NULL
;
1791 context
->speculative_offset
= 0;
1792 context
->speculative_maybe_derived_type
= false;
1795 /* See if speculative type seem to be derrived from outer_type.
1796 Then speculation is valid only if it really is a derivate and derived types
1799 The test does not really look for derivate, but also accepts the case where
1800 outer_type is a field of speculative_outer_type. In this case eiter
1801 MAYBE_DERIVED_TYPE is false and we have full non-speculative information or
1802 the loop bellow will correctly update SPECULATIVE_OUTER_TYPE
1803 and SPECULATIVE_MAYBE_DERIVED_TYPE. */
1804 if (context
->speculative_outer_type
1805 && context
->speculative_offset
>= context
->offset
1806 && contains_type_p (context
->speculative_outer_type
,
1807 context
->offset
- context
->speculative_offset
,
1808 context
->outer_type
))
1809 speculation_valid
= context
->maybe_derived_type
;
1811 clear_speculation (context
);
1813 /* Find the sub-object the constant actually refers to and mark whether it is
1814 an artificial one (as opposed to a user-defined one).
1816 This loop is performed twice; first time for outer_type and second time
1817 for speculative_outer_type. The second iteration has SPECULATIVE set. */
1820 HOST_WIDE_INT pos
, size
;
1823 /* On a match, just return what we found. */
1824 if (TREE_CODE (type
) == TREE_CODE (expected_type
)
1826 || (TREE_CODE (type
) == RECORD_TYPE
1827 && TYPE_BINFO (type
)
1828 && polymorphic_type_binfo_p (TYPE_BINFO (type
))))
1829 && types_same_for_odr (type
, expected_type
))
1833 gcc_assert (speculation_valid
);
1836 /* If we did not match the offset, just give up on speculation. */
1838 || (types_same_for_odr (context
->speculative_outer_type
,
1839 context
->outer_type
)
1840 && (context
->maybe_derived_type
1841 == context
->speculative_maybe_derived_type
)))
1842 clear_speculation (context
);
1847 /* Type can not contain itself on an non-zero offset. In that case
1855 /* If speculation is not valid or we determined type precisely,
1857 if (!speculation_valid
1858 || !context
->maybe_derived_type
)
1860 clear_speculation (context
);
1863 /* Otherwise look into speculation now. */
1867 type
= context
->speculative_outer_type
;
1868 offset
= context
->speculative_offset
;
1874 /* Walk fields and find corresponding on at OFFSET. */
1875 if (TREE_CODE (type
) == RECORD_TYPE
)
1877 for (fld
= TYPE_FIELDS (type
); fld
; fld
= DECL_CHAIN (fld
))
1879 if (TREE_CODE (fld
) != FIELD_DECL
)
1882 pos
= int_bit_position (fld
);
1883 size
= tree_to_uhwi (DECL_SIZE (fld
));
1884 if (pos
<= offset
&& (pos
+ size
) > offset
)
1891 type
= TYPE_MAIN_VARIANT (TREE_TYPE (fld
));
1893 /* DECL_ARTIFICIAL represents a basetype. */
1894 if (!DECL_ARTIFICIAL (fld
))
1898 context
->outer_type
= type
;
1899 context
->offset
= offset
;
1900 /* As soon as we se an field containing the type,
1901 we know we are not looking for derivations. */
1902 context
->maybe_derived_type
= false;
1906 context
->speculative_outer_type
= type
;
1907 context
->speculative_offset
= offset
;
1908 context
->speculative_maybe_derived_type
= false;
1912 else if (TREE_CODE (type
) == ARRAY_TYPE
)
1914 tree subtype
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
1916 /* Give up if we don't know array size. */
1917 if (!tree_fits_shwi_p (TYPE_SIZE (subtype
))
1918 || !tree_to_shwi (TYPE_SIZE (subtype
)) <= 0)
1920 offset
= offset
% tree_to_shwi (TYPE_SIZE (subtype
));
1924 context
->outer_type
= type
;
1925 context
->offset
= offset
;
1926 context
->maybe_derived_type
= false;
1930 context
->speculative_outer_type
= type
;
1931 context
->speculative_offset
= offset
;
1932 context
->speculative_maybe_derived_type
= false;
1935 /* Give up on anything else. */
1940 /* If we failed to find subtype we look for, give up and fall back to the
1941 most generic query. */
1943 clear_speculation (context
);
1946 context
->outer_type
= expected_type
;
1947 context
->offset
= 0;
1948 context
->maybe_derived_type
= true;
1949 context
->maybe_in_construction
= true;
1950 /* POD can be changed to an instance of a polymorphic type by
1951 placement new. Here we play safe and assume that any
1952 non-polymorphic type is POD. */
1953 if ((TREE_CODE (type
) != RECORD_TYPE
1954 || !TYPE_BINFO (type
)
1955 || !polymorphic_type_binfo_p (TYPE_BINFO (type
)))
1956 && (!TYPE_SIZE (type
)
1957 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1958 || (offset
+ tree_to_uhwi (TYPE_SIZE (expected_type
)) <=
1959 tree_to_uhwi (TYPE_SIZE (type
)))))
1964 /* Return true if OUTER_TYPE contains OTR_TYPE at OFFSET. */
1967 contains_type_p (tree outer_type
, HOST_WIDE_INT offset
,
1970 ipa_polymorphic_call_context context
= {offset
, 0,
1971 TYPE_MAIN_VARIANT (outer_type
),
1972 NULL
, false, true, false};
1973 return get_class_context (&context
, otr_type
);
1976 /* Lookup base of BINFO that has virtual table VTABLE with OFFSET. */
1979 subbinfo_with_vtable_at_offset (tree binfo
, unsigned HOST_WIDE_INT offset
,
1982 tree v
= BINFO_VTABLE (binfo
);
1985 unsigned HOST_WIDE_INT this_offset
;
1989 if (!vtable_pointer_value_to_vtable (v
, &v
, &this_offset
))
1992 if (offset
== this_offset
1993 && DECL_ASSEMBLER_NAME (v
) == DECL_ASSEMBLER_NAME (vtable
))
1997 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1998 if (polymorphic_type_binfo_p (base_binfo
))
2000 base_binfo
= subbinfo_with_vtable_at_offset (base_binfo
, offset
, vtable
);
2007 /* T is known constant value of virtual table pointer.
2008 Store virtual table to V and its offset to OFFSET.
2009 Return false if T does not look like virtual table reference. */
2012 vtable_pointer_value_to_vtable (const_tree t
, tree
*v
,
2013 unsigned HOST_WIDE_INT
*offset
)
2015 /* We expect &MEM[(void *)&virtual_table + 16B].
2016 We obtain object's BINFO from the context of the virtual table.
2017 This one contains pointer to virtual table represented via
2018 POINTER_PLUS_EXPR. Verify that this pointer match to what
2019 we propagated through.
2021 In the case of virtual inheritance, the virtual tables may
2022 be nested, i.e. the offset may be different from 16 and we may
2023 need to dive into the type representation. */
2024 if (TREE_CODE (t
) == ADDR_EXPR
2025 && TREE_CODE (TREE_OPERAND (t
, 0)) == MEM_REF
2026 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == ADDR_EXPR
2027 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
2028 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 0))
2030 && DECL_VIRTUAL_P (TREE_OPERAND (TREE_OPERAND
2031 (TREE_OPERAND (t
, 0), 0), 0)))
2033 *v
= TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 0);
2034 *offset
= tree_to_uhwi (TREE_OPERAND (TREE_OPERAND (t
, 0), 1));
2038 /* Alternative representation, used by C++ frontend is POINTER_PLUS_EXPR.
2039 We need to handle it when T comes from static variable initializer or
2041 if (TREE_CODE (t
) == POINTER_PLUS_EXPR
)
2043 *offset
= tree_to_uhwi (TREE_OPERAND (t
, 1));
2044 t
= TREE_OPERAND (t
, 0);
2049 if (TREE_CODE (t
) != ADDR_EXPR
)
2051 *v
= TREE_OPERAND (t
, 0);
2055 /* T is known constant value of virtual table pointer. Return BINFO of the
2059 vtable_pointer_value_to_binfo (const_tree t
)
2062 unsigned HOST_WIDE_INT offset
;
2064 if (!vtable_pointer_value_to_vtable (t
, &vtable
, &offset
))
2067 /* FIXME: for stores of construction vtables we return NULL,
2068 because we do not have BINFO for those. Eventually we should fix
2069 our representation to allow this case to be handled, too.
2070 In the case we see store of BINFO we however may assume
2071 that standard folding will be ale to cope with it. */
2072 return subbinfo_with_vtable_at_offset (TYPE_BINFO (DECL_CONTEXT (vtable
)),
2076 /* We know that the instance is stored in variable or parameter
2077 (not dynamically allocated) and we want to disprove the fact
2078 that it may be in construction at invocation of CALL.
2080 For the variable to be in construction we actually need to
2081 be in constructor of corresponding global variable or
2082 the inline stack of CALL must contain the constructor.
2083 Check this condition. This check works safely only before
2084 IPA passes, because inline stacks may become out of date
2088 decl_maybe_in_construction_p (tree base
, tree outer_type
,
2089 gimple call
, tree function
)
2091 outer_type
= TYPE_MAIN_VARIANT (outer_type
);
2092 gcc_assert (DECL_P (base
));
2094 /* After inlining the code unification optimizations may invalidate
2095 inline stacks. Also we need to give up on global variables after
2096 IPA, because addresses of these may have been propagated to their
2098 if (DECL_STRUCT_FUNCTION (function
)->after_inlining
)
2101 /* Pure functions can not do any changes on the dynamic type;
2102 that require writting to memory. */
2103 if (!auto_var_in_fn_p (base
, function
)
2104 && flags_from_decl_or_type (function
) & (ECF_PURE
| ECF_CONST
))
2107 for (tree block
= gimple_block (call
); block
&& TREE_CODE (block
) == BLOCK
;
2108 block
= BLOCK_SUPERCONTEXT (block
))
2109 if (BLOCK_ABSTRACT_ORIGIN (block
)
2110 && TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block
)) == FUNCTION_DECL
)
2112 tree fn
= BLOCK_ABSTRACT_ORIGIN (block
);
2114 if (TREE_CODE (TREE_TYPE (fn
)) != METHOD_TYPE
2115 || (!DECL_CXX_CONSTRUCTOR_P (fn
)
2116 || !DECL_CXX_DESTRUCTOR_P (fn
)))
2118 /* Watch for clones where we constant propagated the first
2119 argument (pointer to the instance). */
2120 fn
= DECL_ABSTRACT_ORIGIN (fn
);
2122 || !is_global_var (base
)
2123 || TREE_CODE (TREE_TYPE (fn
)) != METHOD_TYPE
2124 || (!DECL_CXX_CONSTRUCTOR_P (fn
)
2125 || !DECL_CXX_DESTRUCTOR_P (fn
)))
2128 if (flags_from_decl_or_type (fn
) & (ECF_PURE
| ECF_CONST
))
2131 /* FIXME: this can go away once we have ODR types equivalency on
2133 if (in_lto_p
&& !polymorphic_type_binfo_p (TYPE_BINFO (outer_type
)))
2135 tree type
= TYPE_MAIN_VARIANT (method_class_type (TREE_TYPE (fn
)));
2136 if (types_same_for_odr (type
, outer_type
))
2140 if (TREE_CODE (base
) == VAR_DECL
2141 && is_global_var (base
))
2143 if (TREE_CODE (TREE_TYPE (function
)) != METHOD_TYPE
2144 || (!DECL_CXX_CONSTRUCTOR_P (function
)
2145 || !DECL_CXX_DESTRUCTOR_P (function
)))
2147 if (!DECL_ABSTRACT_ORIGIN (function
))
2149 /* Watch for clones where we constant propagated the first
2150 argument (pointer to the instance). */
2151 function
= DECL_ABSTRACT_ORIGIN (function
);
2153 || TREE_CODE (TREE_TYPE (function
)) != METHOD_TYPE
2154 || (!DECL_CXX_CONSTRUCTOR_P (function
)
2155 || !DECL_CXX_DESTRUCTOR_P (function
)))
2158 /* FIXME: this can go away once we have ODR types equivalency on
2160 if (in_lto_p
&& !polymorphic_type_binfo_p (TYPE_BINFO (outer_type
)))
2162 tree type
= TYPE_MAIN_VARIANT (method_class_type (TREE_TYPE (function
)));
2163 if (types_same_for_odr (type
, outer_type
))
2169 /* Proudce polymorphic call context for call method of instance
2170 that is located within BASE (that is assumed to be a decl) at OFFSET. */
2173 get_polymorphic_call_info_for_decl (ipa_polymorphic_call_context
*context
,
2174 tree base
, HOST_WIDE_INT offset
)
2176 gcc_assert (DECL_P (base
));
2178 context
->outer_type
= TYPE_MAIN_VARIANT (TREE_TYPE (base
));
2179 context
->offset
= offset
;
2180 context
->speculative_outer_type
= NULL
;
2181 context
->speculative_offset
= 0;
2182 context
->speculative_maybe_derived_type
= true;
2183 /* Make very conservative assumption that all objects
2184 may be in construction.
2185 TODO: ipa-prop already contains code to tell better.
2187 context
->maybe_in_construction
= true;
2188 context
->maybe_derived_type
= false;
2191 /* CST is an invariant (address of decl), try to get meaningful
2192 polymorphic call context for polymorphic call of method
2193 if instance of OTR_TYPE that is located at OFFSET of this invariant.
2194 Return FALSE if nothing meaningful can be found. */
2197 get_polymorphic_call_info_from_invariant (ipa_polymorphic_call_context
*context
,
2200 HOST_WIDE_INT offset
)
2202 HOST_WIDE_INT offset2
, size
, max_size
;
2205 if (TREE_CODE (cst
) != ADDR_EXPR
)
2208 cst
= TREE_OPERAND (cst
, 0);
2209 base
= get_ref_base_and_extent (cst
, &offset2
, &size
, &max_size
);
2210 if (!DECL_P (base
) || max_size
== -1 || max_size
!= size
)
2213 /* Only type inconsistent programs can have otr_type that is
2214 not part of outer type. */
2215 if (!contains_type_p (TREE_TYPE (base
), offset
, otr_type
))
2218 get_polymorphic_call_info_for_decl (context
, base
, offset
);
2222 /* See if OP is SSA name initialized as a copy or by single assignment.
2223 If so, walk the SSA graph up. */
2226 walk_ssa_copies (tree op
)
2229 while (TREE_CODE (op
) == SSA_NAME
2230 && !SSA_NAME_IS_DEFAULT_DEF (op
)
2231 && SSA_NAME_DEF_STMT (op
)
2232 && gimple_assign_single_p (SSA_NAME_DEF_STMT (op
)))
2234 if (gimple_assign_load_p (SSA_NAME_DEF_STMT (op
)))
2236 op
= gimple_assign_rhs1 (SSA_NAME_DEF_STMT (op
));
2242 /* Given REF call in FNDECL, determine class of the polymorphic
2243 call (OTR_TYPE), its token (OTR_TOKEN) and CONTEXT.
2244 CALL is optional argument giving the actual statement (usually call) where
2245 the context is used.
2246 Return pointer to object described by the context */
2249 get_polymorphic_call_info (tree fndecl
,
2252 HOST_WIDE_INT
*otr_token
,
2253 ipa_polymorphic_call_context
*context
,
2257 *otr_type
= obj_type_ref_class (ref
);
2258 *otr_token
= tree_to_uhwi (OBJ_TYPE_REF_TOKEN (ref
));
2260 /* Set up basic info in case we find nothing interesting in the analysis. */
2261 context
->speculative_outer_type
= NULL
;
2262 context
->speculative_offset
= 0;
2263 context
->speculative_maybe_derived_type
= true;
2264 context
->outer_type
= TYPE_MAIN_VARIANT (*otr_type
);
2265 context
->offset
= 0;
2266 base_pointer
= OBJ_TYPE_REF_OBJECT (ref
);
2267 context
->maybe_derived_type
= true;
2268 context
->maybe_in_construction
= true;
2270 /* Walk SSA for outer object. */
2273 base_pointer
= walk_ssa_copies (base_pointer
);
2274 if (TREE_CODE (base_pointer
) == ADDR_EXPR
)
2276 HOST_WIDE_INT size
, max_size
;
2277 HOST_WIDE_INT offset2
;
2278 tree base
= get_ref_base_and_extent (TREE_OPERAND (base_pointer
, 0),
2279 &offset2
, &size
, &max_size
);
2281 /* If this is a varying address, punt. */
2282 if ((TREE_CODE (base
) == MEM_REF
|| DECL_P (base
))
2284 && max_size
== size
)
2286 /* We found dereference of a pointer. Type of the pointer
2287 and MEM_REF is meaningless, but we can look futher. */
2288 if (TREE_CODE (base
) == MEM_REF
)
2290 base_pointer
= TREE_OPERAND (base
, 0);
2292 += offset2
+ mem_ref_offset (base
).to_short_addr () * BITS_PER_UNIT
;
2293 context
->outer_type
= NULL
;
2295 /* We found base object. In this case the outer_type
2297 else if (DECL_P (base
))
2299 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (base
)));
2301 /* Only type inconsistent programs can have otr_type that is
2302 not part of outer type. */
2303 if (!contains_type_p (TREE_TYPE (base
),
2304 context
->offset
+ offset2
, *otr_type
))
2306 /* Use OTR_TOKEN = INT_MAX as a marker of probably type inconsistent
2307 code sequences; we arrange the calls to be builtin_unreachable
2309 *otr_token
= INT_MAX
;
2310 return base_pointer
;
2312 get_polymorphic_call_info_for_decl (context
, base
,
2313 context
->offset
+ offset2
);
2314 if (context
->maybe_in_construction
&& call
)
2315 context
->maybe_in_construction
2316 = decl_maybe_in_construction_p (base
,
2317 context
->outer_type
,
2319 current_function_decl
);
2320 return base_pointer
;
2328 else if (TREE_CODE (base_pointer
) == POINTER_PLUS_EXPR
2329 && tree_fits_uhwi_p (TREE_OPERAND (base_pointer
, 1)))
2331 context
->offset
+= tree_to_shwi (TREE_OPERAND (base_pointer
, 1))
2333 base_pointer
= TREE_OPERAND (base_pointer
, 0);
2340 /* Try to determine type of the outer object. */
2341 if (TREE_CODE (base_pointer
) == SSA_NAME
2342 && SSA_NAME_IS_DEFAULT_DEF (base_pointer
)
2343 && TREE_CODE (SSA_NAME_VAR (base_pointer
)) == PARM_DECL
)
2345 /* See if parameter is THIS pointer of a method. */
2346 if (TREE_CODE (TREE_TYPE (fndecl
)) == METHOD_TYPE
2347 && SSA_NAME_VAR (base_pointer
) == DECL_ARGUMENTS (fndecl
))
2350 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (base_pointer
)));
2351 gcc_assert (TREE_CODE (context
->outer_type
) == RECORD_TYPE
);
2353 /* Dynamic casting has possibly upcasted the type
2354 in the hiearchy. In this case outer type is less
2355 informative than inner type and we should forget
2357 if (!contains_type_p (context
->outer_type
, context
->offset
,
2360 context
->outer_type
= NULL
;
2361 return base_pointer
;
2364 /* If the function is constructor or destructor, then
2365 the type is possibly in construction, but we know
2366 it is not derived type. */
2367 if (DECL_CXX_CONSTRUCTOR_P (fndecl
)
2368 || DECL_CXX_DESTRUCTOR_P (fndecl
))
2370 context
->maybe_in_construction
= true;
2371 context
->maybe_derived_type
= false;
2375 context
->maybe_derived_type
= true;
2376 context
->maybe_in_construction
= false;
2378 return base_pointer
;
2380 /* Non-PODs passed by value are really passed by invisible
2381 reference. In this case we also know the type of the
2383 if (DECL_BY_REFERENCE (SSA_NAME_VAR (base_pointer
)))
2386 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (base_pointer
)));
2387 gcc_assert (!POINTER_TYPE_P (context
->outer_type
));
2388 /* Only type inconsistent programs can have otr_type that is
2389 not part of outer type. */
2390 if (!contains_type_p (context
->outer_type
, context
->offset
,
2393 /* Use OTR_TOKEN = INT_MAX as a marker of probably type inconsistent
2394 code sequences; we arrange the calls to be builtin_unreachable
2396 *otr_token
= INT_MAX
;
2397 return base_pointer
;
2399 context
->maybe_derived_type
= false;
2400 context
->maybe_in_construction
= false;
2401 return base_pointer
;
2405 tree base_type
= TREE_TYPE (base_pointer
);
2407 if (TREE_CODE (base_pointer
) == SSA_NAME
2408 && SSA_NAME_IS_DEFAULT_DEF (base_pointer
)
2409 && TREE_CODE (SSA_NAME_VAR (base_pointer
)) != PARM_DECL
)
2411 /* Use OTR_TOKEN = INT_MAX as a marker of probably type inconsistent
2412 code sequences; we arrange the calls to be builtin_unreachable
2414 *otr_token
= INT_MAX
;
2415 return base_pointer
;
2417 if (TREE_CODE (base_pointer
) == SSA_NAME
2418 && SSA_NAME_DEF_STMT (base_pointer
)
2419 && gimple_assign_single_p (SSA_NAME_DEF_STMT (base_pointer
)))
2420 base_type
= TREE_TYPE (gimple_assign_rhs1
2421 (SSA_NAME_DEF_STMT (base_pointer
)));
2423 if (POINTER_TYPE_P (base_type
)
2424 && contains_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (base_type
)),
2428 context
->speculative_outer_type
= TYPE_MAIN_VARIANT
2429 (TREE_TYPE (base_type
));
2430 context
->speculative_offset
= context
->offset
;
2431 context
->speculative_maybe_derived_type
= true;
2433 /* TODO: There are multiple ways to derive a type. For instance
2434 if BASE_POINTER is passed to an constructor call prior our refernece.
2435 We do not make this type of flow sensitive analysis yet. */
2436 return base_pointer
;
2439 /* Walk bases of OUTER_TYPE that contain OTR_TYPE at OFFSET.
2440 Lookup their respecitve virtual methods for OTR_TOKEN and OTR_TYPE
2441 and insert them to NODES.
2443 MATCHED_VTABLES and INSERTED is used to avoid duplicated work. */
2446 record_targets_from_bases (tree otr_type
,
2447 HOST_WIDE_INT otr_token
,
2449 HOST_WIDE_INT offset
,
2450 vec
<cgraph_node
*> &nodes
,
2451 hash_set
<tree
> *inserted
,
2452 hash_set
<tree
> *matched_vtables
,
2457 HOST_WIDE_INT pos
, size
;
2461 if (types_same_for_odr (outer_type
, otr_type
))
2464 for (fld
= TYPE_FIELDS (outer_type
); fld
; fld
= DECL_CHAIN (fld
))
2466 if (TREE_CODE (fld
) != FIELD_DECL
)
2469 pos
= int_bit_position (fld
);
2470 size
= tree_to_shwi (DECL_SIZE (fld
));
2471 if (pos
<= offset
&& (pos
+ size
) > offset
2472 /* Do not get confused by zero sized bases. */
2473 && polymorphic_type_binfo_p (TYPE_BINFO (TREE_TYPE (fld
))))
2476 /* Within a class type we should always find correcponding fields. */
2477 gcc_assert (fld
&& TREE_CODE (TREE_TYPE (fld
)) == RECORD_TYPE
);
2479 /* Nonbasetypes should have been stripped by outer_class_type. */
2480 gcc_assert (DECL_ARTIFICIAL (fld
));
2482 outer_type
= TREE_TYPE (fld
);
2485 base_binfo
= get_binfo_at_offset (TYPE_BINFO (outer_type
),
2489 gcc_assert (odr_violation_reported
);
2492 gcc_assert (base_binfo
);
2493 if (!matched_vtables
->add (BINFO_VTABLE (base_binfo
)))
2496 tree target
= gimple_get_virt_method_for_binfo (otr_token
,
2499 if (!target
|| ! DECL_CXX_DESTRUCTOR_P (target
))
2500 maybe_record_node (nodes
, target
, inserted
, can_refer
, completep
);
2501 matched_vtables
->add (BINFO_VTABLE (base_binfo
));
2506 /* When virtual table is removed, we may need to flush the cache. */
2509 devirt_variable_node_removal_hook (varpool_node
*n
,
2510 void *d ATTRIBUTE_UNUSED
)
2512 if (cached_polymorphic_call_targets
2513 && DECL_VIRTUAL_P (n
->decl
)
2514 && type_in_anonymous_namespace_p (DECL_CONTEXT (n
->decl
)))
2515 free_polymorphic_call_targets_hash ();
2518 /* Record about how many calls would benefit from given type to be final. */
2519 struct odr_type_warn_count
2522 gcov_type dyn_count
;
2525 /* Record about how many calls would benefit from given method to be final. */
2526 struct decl_warn_count
2530 gcov_type dyn_count
;
2533 /* Information about type and decl warnings. */
2534 struct final_warning_record
2536 gcov_type dyn_count
;
2537 vec
<odr_type_warn_count
> type_warnings
;
2538 hash_map
<tree
, decl_warn_count
> decl_warnings
;
2540 struct final_warning_record
*final_warning_records
;
2542 /* Return vector containing possible targets of polymorphic call of type
2543 OTR_TYPE caling method OTR_TOKEN within type of OTR_OUTER_TYPE and OFFSET.
2544 If INCLUDE_BASES is true, walk also base types of OUTER_TYPES containig
2545 OTR_TYPE and include their virtual method. This is useful for types
2546 possibly in construction or destruction where the virtual table may
2547 temporarily change to one of base types. INCLUDE_DERIVER_TYPES make
2548 us to walk the inheritance graph for all derivations.
2550 OTR_TOKEN == INT_MAX is used to mark calls that are provably
2551 undefined and should be redirected to unreachable.
2553 If COMPLETEP is non-NULL, store true if the list is complete.
2554 CACHE_TOKEN (if non-NULL) will get stored to an unique ID of entry
2555 in the target cache. If user needs to visit every target list
2556 just once, it can memoize them.
2558 SPECULATION_TARGETS specify number of targets that are speculatively
2559 likely. These include targets specified by the speculative part
2560 of polymoprhic call context and also exclude all targets for classes
2563 Returned vector is placed into cache. It is NOT caller's responsibility
2564 to free it. The vector can be freed on cgraph_remove_node call if
2565 the particular node is a virtual function present in the cache. */
2568 possible_polymorphic_call_targets (tree otr_type
,
2569 HOST_WIDE_INT otr_token
,
2570 ipa_polymorphic_call_context context
,
2573 int *speculative_targetsp
)
2575 static struct cgraph_node_hook_list
*node_removal_hook_holder
;
2576 vec
<cgraph_node
*> nodes
= vNULL
;
2577 vec
<tree
> bases_to_consider
= vNULL
;
2578 odr_type type
, outer_type
;
2579 polymorphic_call_target_d key
;
2580 polymorphic_call_target_d
**slot
;
2585 bool skipped
= false;
2587 otr_type
= TYPE_MAIN_VARIANT (otr_type
);
2589 /* If ODR is not initialized, return empty incomplete list. */
2595 *cache_token
= NULL
;
2596 if (speculative_targetsp
)
2597 *speculative_targetsp
= 0;
2601 /* If we hit type inconsistency, just return empty list of targets. */
2602 if (otr_token
== INT_MAX
)
2607 *cache_token
= NULL
;
2608 if (speculative_targetsp
)
2609 *speculative_targetsp
= 0;
2613 /* Do not bother to compute speculative info when user do not asks for it. */
2614 if (!speculative_targetsp
|| !context
.speculative_outer_type
)
2615 clear_speculation (&context
);
2617 type
= get_odr_type (otr_type
, true);
2619 /* Recording type variants would wast results cache. */
2620 gcc_assert (!context
.outer_type
2621 || TYPE_MAIN_VARIANT (context
.outer_type
) == context
.outer_type
);
2623 /* Lookup the outer class type we want to walk. */
2624 if ((context
.outer_type
|| context
.speculative_outer_type
)
2625 && !get_class_context (&context
, otr_type
))
2630 *cache_token
= NULL
;
2631 if (speculative_targetsp
)
2632 *speculative_targetsp
= 0;
2636 /* Check that get_class_context kept the main variant. */
2637 gcc_assert (!context
.outer_type
2638 || TYPE_MAIN_VARIANT (context
.outer_type
) == context
.outer_type
);
2640 /* We canonicalize our query, so we do not need extra hashtable entries. */
2642 /* Without outer type, we have no use for offset. Just do the
2643 basic search from innter type */
2644 if (!context
.outer_type
)
2646 context
.outer_type
= otr_type
;
2649 /* We need to update our hiearchy if the type does not exist. */
2650 outer_type
= get_odr_type (context
.outer_type
, true);
2651 /* If the type is complete, there are no derivations. */
2652 if (TYPE_FINAL_P (outer_type
->type
))
2653 context
.maybe_derived_type
= false;
2655 /* Initialize query cache. */
2656 if (!cached_polymorphic_call_targets
)
2658 cached_polymorphic_call_targets
= new hash_set
<cgraph_node
*>;
2659 polymorphic_call_target_hash
2660 = new polymorphic_call_target_hash_type (23);
2661 if (!node_removal_hook_holder
)
2663 node_removal_hook_holder
=
2664 cgraph_add_node_removal_hook (&devirt_node_removal_hook
, NULL
);
2665 varpool_add_node_removal_hook (&devirt_variable_node_removal_hook
,
2670 /* Lookup cached answer. */
2672 key
.otr_token
= otr_token
;
2673 key
.context
= context
;
2674 slot
= polymorphic_call_target_hash
->find_slot (&key
, INSERT
);
2676 *cache_token
= (void *)*slot
;
2680 *completep
= (*slot
)->complete
;
2681 if (speculative_targetsp
)
2682 *speculative_targetsp
= (*slot
)->speculative_targets
;
2683 if ((*slot
)->type_warning
&& final_warning_records
)
2685 final_warning_records
->type_warnings
[(*slot
)->type_warning
- 1].count
++;
2686 final_warning_records
->type_warnings
[(*slot
)->type_warning
- 1].dyn_count
2687 += final_warning_records
->dyn_count
;
2689 if ((*slot
)->decl_warning
&& final_warning_records
)
2691 struct decl_warn_count
*c
=
2692 final_warning_records
->decl_warnings
.get ((*slot
)->decl_warning
);
2694 c
->dyn_count
+= final_warning_records
->dyn_count
;
2696 return (*slot
)->targets
;
2701 /* Do actual search. */
2702 timevar_push (TV_IPA_VIRTUAL_CALL
);
2703 *slot
= XCNEW (polymorphic_call_target_d
);
2705 *cache_token
= (void *)*slot
;
2706 (*slot
)->type
= type
;
2707 (*slot
)->otr_token
= otr_token
;
2708 (*slot
)->context
= context
;
2709 (*slot
)->speculative_targets
= 0;
2711 hash_set
<tree
> inserted
;
2712 hash_set
<tree
> matched_vtables
;
2714 /* First insert targets we speculatively identified as likely. */
2715 if (context
.speculative_outer_type
)
2717 odr_type speculative_outer_type
;
2718 bool speculation_complete
= true;
2720 /* First insert target from type itself and check if it may have derived types. */
2721 speculative_outer_type
= get_odr_type (context
.speculative_outer_type
, true);
2722 if (TYPE_FINAL_P (speculative_outer_type
->type
))
2723 context
.speculative_maybe_derived_type
= false;
2724 binfo
= get_binfo_at_offset (TYPE_BINFO (speculative_outer_type
->type
),
2725 context
.speculative_offset
, otr_type
);
2727 target
= gimple_get_virt_method_for_binfo (otr_token
, binfo
,
2732 /* In the case we get complete method, we don't need
2733 to walk derivations. */
2734 if (target
&& DECL_FINAL_P (target
))
2735 context
.speculative_maybe_derived_type
= false;
2736 if (type_possibly_instantiated_p (speculative_outer_type
->type
))
2737 maybe_record_node (nodes
, target
, &inserted
, can_refer
, &speculation_complete
);
2739 matched_vtables
.add (BINFO_VTABLE (binfo
));
2741 /* Next walk recursively all derived types. */
2742 if (context
.speculative_maybe_derived_type
)
2743 for (i
= 0; i
< speculative_outer_type
->derived_types
.length(); i
++)
2744 possible_polymorphic_call_targets_1 (nodes
, &inserted
,
2747 speculative_outer_type
->derived_types
[i
],
2748 otr_token
, speculative_outer_type
->type
,
2749 context
.speculative_offset
,
2750 &speculation_complete
,
2753 (*slot
)->speculative_targets
= nodes
.length();
2756 /* First see virtual method of type itself. */
2757 binfo
= get_binfo_at_offset (TYPE_BINFO (outer_type
->type
),
2758 context
.offset
, otr_type
);
2760 target
= gimple_get_virt_method_for_binfo (otr_token
, binfo
,
2764 gcc_assert (odr_violation_reported
);
2768 /* Destructors are never called through construction virtual tables,
2769 because the type is always known. */
2770 if (target
&& DECL_CXX_DESTRUCTOR_P (target
))
2771 context
.maybe_in_construction
= false;
2775 /* In the case we get complete method, we don't need
2776 to walk derivations. */
2777 if (DECL_FINAL_P (target
))
2778 context
.maybe_derived_type
= false;
2781 /* If OUTER_TYPE is abstract, we know we are not seeing its instance. */
2782 if (type_possibly_instantiated_p (outer_type
->type
))
2783 maybe_record_node (nodes
, target
, &inserted
, can_refer
, &complete
);
2787 gcc_assert (in_lto_p
|| context
.maybe_derived_type
);
2791 matched_vtables
.add (BINFO_VTABLE (binfo
));
2793 /* Next walk recursively all derived types. */
2794 if (context
.maybe_derived_type
)
2796 for (i
= 0; i
< outer_type
->derived_types
.length(); i
++)
2797 possible_polymorphic_call_targets_1 (nodes
, &inserted
,
2800 outer_type
->derived_types
[i
],
2801 otr_token
, outer_type
->type
,
2802 context
.offset
, &complete
,
2804 context
.maybe_in_construction
);
2806 if (!outer_type
->all_derivations_known
)
2808 if (final_warning_records
)
2811 && nodes
.length () == 1
2812 && warn_suggest_final_types
2813 && !outer_type
->derived_types
.length ())
2815 if (outer_type
->id
>= (int)final_warning_records
->type_warnings
.length ())
2816 final_warning_records
->type_warnings
.safe_grow_cleared
2817 (odr_types
.length ());
2818 final_warning_records
->type_warnings
[outer_type
->id
].count
++;
2819 final_warning_records
->type_warnings
[outer_type
->id
].dyn_count
2820 += final_warning_records
->dyn_count
;
2821 (*slot
)->type_warning
= outer_type
->id
+ 1;
2824 && warn_suggest_final_methods
2825 && nodes
.length () == 1
2826 && types_same_for_odr (DECL_CONTEXT (nodes
[0]->decl
),
2830 struct decl_warn_count
&c
=
2831 final_warning_records
->decl_warnings
.get_or_insert
2832 (nodes
[0]->decl
, &existed
);
2837 c
.dyn_count
+= final_warning_records
->dyn_count
;
2842 c
.dyn_count
= final_warning_records
->dyn_count
;
2843 c
.decl
= nodes
[0]->decl
;
2845 (*slot
)->decl_warning
= nodes
[0]->decl
;
2852 /* Finally walk bases, if asked to. */
2853 if (!(*slot
)->speculative_targets
)
2854 (*slot
)->speculative_targets
= nodes
.length();
2856 /* Destructors are never called through construction virtual tables,
2857 because the type is always known. One of entries may be cxa_pure_virtual
2858 so look to at least two of them. */
2859 if (context
.maybe_in_construction
)
2860 for (i
=0 ; i
< MIN (nodes
.length (), 2); i
++)
2861 if (DECL_CXX_DESTRUCTOR_P (nodes
[i
]->decl
))
2862 context
.maybe_in_construction
= false;
2863 if (context
.maybe_in_construction
)
2865 if (type
!= outer_type
2867 || (context
.maybe_derived_type
2868 && !type_all_derivations_known_p (outer_type
->type
))))
2869 record_targets_from_bases (otr_type
, otr_token
, outer_type
->type
,
2870 context
.offset
, nodes
, &inserted
,
2871 &matched_vtables
, &complete
);
2873 maybe_record_node (nodes
, target
, &inserted
, can_refer
, &complete
);
2874 for (i
= 0; i
< bases_to_consider
.length(); i
++)
2875 maybe_record_node (nodes
, bases_to_consider
[i
], &inserted
, can_refer
, &complete
);
2877 bases_to_consider
.release();
2879 (*slot
)->targets
= nodes
;
2880 (*slot
)->complete
= complete
;
2882 *completep
= complete
;
2883 if (speculative_targetsp
)
2884 *speculative_targetsp
= (*slot
)->speculative_targets
;
2886 timevar_pop (TV_IPA_VIRTUAL_CALL
);
2891 add_decl_warning (const tree
&key ATTRIBUTE_UNUSED
, const decl_warn_count
&value
,
2892 vec
<const decl_warn_count
*> *vec
)
2894 vec
->safe_push (&value
);
2898 /* Dump all possible targets of a polymorphic call. */
2901 dump_possible_polymorphic_call_targets (FILE *f
,
2903 HOST_WIDE_INT otr_token
,
2904 const ipa_polymorphic_call_context
&ctx
)
2906 vec
<cgraph_node
*> targets
;
2908 odr_type type
= get_odr_type (TYPE_MAIN_VARIANT (otr_type
), false);
2914 targets
= possible_polymorphic_call_targets (otr_type
, otr_token
,
2916 &final
, NULL
, &speculative
);
2917 fprintf (f
, " Targets of polymorphic call of type %i:", type
->id
);
2918 print_generic_expr (f
, type
->type
, TDF_SLIM
);
2919 fprintf (f
, " token %i\n", (int)otr_token
);
2920 if (ctx
.outer_type
|| ctx
.offset
)
2922 fprintf (f
, " Contained in type:");
2923 print_generic_expr (f
, ctx
.outer_type
, TDF_SLIM
);
2924 fprintf (f
, " at offset "HOST_WIDE_INT_PRINT_DEC
"\n",
2927 if (ctx
.speculative_outer_type
)
2929 fprintf (f
, " Speculatively contained in type:");
2930 print_generic_expr (f
, ctx
.speculative_outer_type
, TDF_SLIM
);
2931 fprintf (f
, " at offset "HOST_WIDE_INT_PRINT_DEC
"\n",
2932 ctx
.speculative_offset
);
2935 fprintf (f
, " %s%s%s%s\n ",
2936 final
? "This is a complete list." :
2937 "This is partial list; extra targets may be defined in other units.",
2938 ctx
.maybe_in_construction
? " (base types included)" : "",
2939 ctx
.maybe_derived_type
? " (derived types included)" : "",
2940 ctx
.speculative_maybe_derived_type
? " (speculative derived types included)" : "");
2941 for (i
= 0; i
< targets
.length (); i
++)
2944 if (i
== (unsigned)speculative
)
2945 fprintf (f
, "\n Targets that are not likely:\n"
2948 name
= cplus_demangle_v3 (targets
[i
]->asm_name (), 0);
2949 fprintf (f
, " %s/%i", name
? name
: targets
[i
]->name (), targets
[i
]->order
);
2952 if (!targets
[i
]->definition
)
2953 fprintf (f
, " (no definition%s)",
2954 DECL_DECLARED_INLINE_P (targets
[i
]->decl
)
2957 fprintf (f
, "\n\n");
2961 /* Return true if N can be possibly target of a polymorphic call of
2962 OTR_TYPE/OTR_TOKEN. */
2965 possible_polymorphic_call_target_p (tree otr_type
,
2966 HOST_WIDE_INT otr_token
,
2967 const ipa_polymorphic_call_context
&ctx
,
2968 struct cgraph_node
*n
)
2970 vec
<cgraph_node
*> targets
;
2972 enum built_in_function fcode
;
2975 if (TREE_CODE (TREE_TYPE (n
->decl
)) == FUNCTION_TYPE
2976 && ((fcode
= DECL_FUNCTION_CODE (n
->decl
))
2977 == BUILT_IN_UNREACHABLE
2978 || fcode
== BUILT_IN_TRAP
))
2983 targets
= possible_polymorphic_call_targets (otr_type
, otr_token
, ctx
, &final
);
2984 for (i
= 0; i
< targets
.length (); i
++)
2985 if (n
->semantically_equivalent_p (targets
[i
]))
2988 /* At a moment we allow middle end to dig out new external declarations
2989 as a targets of polymorphic calls. */
2990 if (!final
&& !n
->definition
)
2996 /* After callgraph construction new external nodes may appear.
2997 Add them into the graph. */
3000 update_type_inheritance_graph (void)
3002 struct cgraph_node
*n
;
3006 free_polymorphic_call_targets_hash ();
3007 timevar_push (TV_IPA_INHERITANCE
);
3008 /* We reconstruct the graph starting from types of all methods seen in the
3010 FOR_EACH_FUNCTION (n
)
3011 if (DECL_VIRTUAL_P (n
->decl
)
3013 && n
->real_symbol_p ())
3014 get_odr_type (method_class_type (TYPE_MAIN_VARIANT (TREE_TYPE (n
->decl
))),
3016 timevar_pop (TV_IPA_INHERITANCE
);
3020 /* Return true if N looks like likely target of a polymorphic call.
3021 Rule out cxa_pure_virtual, noreturns, function declared cold and
3022 other obvious cases. */
3025 likely_target_p (struct cgraph_node
*n
)
3028 /* cxa_pure_virtual and similar things are not likely. */
3029 if (TREE_CODE (TREE_TYPE (n
->decl
)) != METHOD_TYPE
)
3031 flags
= flags_from_decl_or_type (n
->decl
);
3032 if (flags
& ECF_NORETURN
)
3034 if (lookup_attribute ("cold",
3035 DECL_ATTRIBUTES (n
->decl
)))
3037 if (n
->frequency
< NODE_FREQUENCY_NORMAL
)
3039 /* If there are no virtual tables refering the target alive,
3040 the only way the target can be called is an instance comming from other
3041 compilation unit; speculative devirtualization is build around an
3042 assumption that won't happen. */
3043 if (!referenced_from_vtable_p (n
))
3048 /* Compare type warning records P1 and P2 and chose one with larger count;
3049 helper for qsort. */
3052 type_warning_cmp (const void *p1
, const void *p2
)
3054 const odr_type_warn_count
*t1
= (const odr_type_warn_count
*)p1
;
3055 const odr_type_warn_count
*t2
= (const odr_type_warn_count
*)p2
;
3057 if (t1
->dyn_count
< t2
->dyn_count
)
3059 if (t1
->dyn_count
> t2
->dyn_count
)
3061 return t2
->count
- t1
->count
;
3064 /* Compare decl warning records P1 and P2 and chose one with larger count;
3065 helper for qsort. */
3068 decl_warning_cmp (const void *p1
, const void *p2
)
3070 const decl_warn_count
*t1
= *(const decl_warn_count
* const *)p1
;
3071 const decl_warn_count
*t2
= *(const decl_warn_count
* const *)p2
;
3073 if (t1
->dyn_count
< t2
->dyn_count
)
3075 if (t1
->dyn_count
> t2
->dyn_count
)
3077 return t2
->count
- t1
->count
;
3080 /* The ipa-devirt pass.
3081 When polymorphic call has only one likely target in the unit,
3082 turn it into speculative call. */
3087 struct cgraph_node
*n
;
3088 hash_set
<void *> bad_call_targets
;
3089 struct cgraph_edge
*e
;
3091 int npolymorphic
= 0, nspeculated
= 0, nconverted
= 0, ncold
= 0;
3092 int nmultiple
= 0, noverwritable
= 0, ndevirtualized
= 0, nnotdefined
= 0;
3093 int nwrong
= 0, nok
= 0, nexternal
= 0, nartificial
= 0;
3095 /* We can output -Wsuggest-final-methods and -Wsuggest-final-types warnings.
3096 This is implemented by setting up final_warning_records that are updated
3097 by get_polymorphic_call_targets.
3098 We need to clear cache in this case to trigger recomputation of all
3100 if (warn_suggest_final_methods
|| warn_suggest_final_types
)
3102 final_warning_records
= new (final_warning_record
);
3103 final_warning_records
->type_warnings
= vNULL
;
3104 final_warning_records
->type_warnings
.safe_grow_cleared (odr_types
.length ());
3105 free_polymorphic_call_targets_hash ();
3108 FOR_EACH_DEFINED_FUNCTION (n
)
3110 bool update
= false;
3111 if (dump_file
&& n
->indirect_calls
)
3112 fprintf (dump_file
, "\n\nProcesing function %s/%i\n",
3113 n
->name (), n
->order
);
3114 for (e
= n
->indirect_calls
; e
; e
= e
->next_callee
)
3115 if (e
->indirect_info
->polymorphic
)
3117 struct cgraph_node
*likely_target
= NULL
;
3120 int speculative_targets
;
3122 if (final_warning_records
)
3123 final_warning_records
->dyn_count
= e
->count
;
3125 vec
<cgraph_node
*>targets
3126 = possible_polymorphic_call_targets
3127 (e
, &final
, &cache_token
, &speculative_targets
);
3131 dump_possible_polymorphic_call_targets
3136 if (!flag_devirtualize_speculatively
)
3139 if (!cgraph_maybe_hot_edge_p (e
))
3142 fprintf (dump_file
, "Call is cold\n\n");
3149 fprintf (dump_file
, "Call is aready speculated\n\n");
3152 /* When dumping see if we agree with speculation. */
3156 if (bad_call_targets
.contains (cache_token
))
3159 fprintf (dump_file
, "Target list is known to be useless\n\n");
3163 for (i
= 0; i
< targets
.length (); i
++)
3164 if (likely_target_p (targets
[i
]))
3168 if (i
< (unsigned) speculative_targets
)
3170 likely_target
= NULL
;
3172 fprintf (dump_file
, "More than one likely target\n\n");
3177 likely_target
= targets
[i
];
3181 bad_call_targets
.add (cache_token
);
3184 /* This is reached only when dumping; check if we agree or disagree
3185 with the speculation. */
3188 struct cgraph_edge
*e2
;
3189 struct ipa_ref
*ref
;
3190 cgraph_speculative_call_info (e
, e2
, e
, ref
);
3191 if (e2
->callee
->ultimate_alias_target ()
3192 == likely_target
->ultimate_alias_target ())
3194 fprintf (dump_file
, "We agree with speculation\n\n");
3199 fprintf (dump_file
, "We disagree with speculation\n\n");
3204 if (!likely_target
->definition
)
3207 fprintf (dump_file
, "Target is not an definition\n\n");
3211 /* Do not introduce new references to external symbols. While we
3212 can handle these just well, it is common for programs to
3213 incorrectly with headers defining methods they are linked
3215 if (DECL_EXTERNAL (likely_target
->decl
))
3218 fprintf (dump_file
, "Target is external\n\n");
3222 /* Don't use an implicitly-declared destructor (c++/58678). */
3223 struct cgraph_node
*non_thunk_target
3224 = likely_target
->function_symbol ();
3225 if (DECL_ARTIFICIAL (non_thunk_target
->decl
)
3226 && DECL_COMDAT (non_thunk_target
->decl
))
3229 fprintf (dump_file
, "Target is artificial\n\n");
3233 if (likely_target
->get_availability () <= AVAIL_INTERPOSABLE
3234 && likely_target
->can_be_discarded_p ())
3237 fprintf (dump_file
, "Target is overwritable\n\n");
3241 else if (dbg_cnt (devirt
))
3243 if (dump_enabled_p ())
3245 location_t locus
= gimple_location_safe (e
->call_stmt
);
3246 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS
, locus
,
3247 "speculatively devirtualizing call in %s/%i to %s/%i\n",
3248 n
->name (), n
->order
,
3249 likely_target
->name (),
3250 likely_target
->order
);
3252 if (!likely_target
->can_be_discarded_p ())
3255 alias
= dyn_cast
<cgraph_node
*> (likely_target
->noninterposable_alias ());
3257 likely_target
= alias
;
3261 cgraph_turn_edge_to_speculative
3262 (e
, likely_target
, e
->count
* 8 / 10, e
->frequency
* 8 / 10);
3266 inline_update_overall_summary (n
);
3268 if (warn_suggest_final_methods
|| warn_suggest_final_types
)
3270 if (warn_suggest_final_types
)
3272 final_warning_records
->type_warnings
.qsort (type_warning_cmp
);
3273 for (unsigned int i
= 0;
3274 i
< final_warning_records
->type_warnings
.length (); i
++)
3275 if (final_warning_records
->type_warnings
[i
].count
)
3277 odr_type type
= odr_types
[i
];
3278 warning_at (DECL_SOURCE_LOCATION (TYPE_NAME (type
->type
)),
3279 OPT_Wsuggest_final_types
,
3280 "Declaring type %qD final "
3281 "would enable devirtualization of %i calls",
3283 final_warning_records
->type_warnings
[i
].count
);
3287 if (warn_suggest_final_methods
)
3289 vec
<const decl_warn_count
*> decl_warnings_vec
= vNULL
;
3291 final_warning_records
->decl_warnings
.traverse
3292 <vec
<const decl_warn_count
*> *, add_decl_warning
> (&decl_warnings_vec
);
3293 decl_warnings_vec
.qsort (decl_warning_cmp
);
3294 for (unsigned int i
= 0; i
< decl_warnings_vec
.length (); i
++)
3296 tree decl
= decl_warnings_vec
[i
]->decl
;
3297 int count
= decl_warnings_vec
[i
]->count
;
3299 if (DECL_CXX_DESTRUCTOR_P (decl
))
3300 warning_at (DECL_SOURCE_LOCATION (decl
),
3301 OPT_Wsuggest_final_methods
,
3302 "Declaring virtual destructor of %qD final "
3303 "would enable devirtualization of %i calls",
3304 DECL_CONTEXT (decl
), count
);
3306 warning_at (DECL_SOURCE_LOCATION (decl
),
3307 OPT_Wsuggest_final_methods
,
3308 "Declaring method %qD final "
3309 "would enable devirtualization of %i calls",
3314 delete (final_warning_records
);
3315 final_warning_records
= 0;
3320 "%i polymorphic calls, %i devirtualized,"
3321 " %i speculatively devirtualized, %i cold\n"
3322 "%i have multiple targets, %i overwritable,"
3323 " %i already speculated (%i agree, %i disagree),"
3324 " %i external, %i not defined, %i artificial\n",
3325 npolymorphic
, ndevirtualized
, nconverted
, ncold
,
3326 nmultiple
, noverwritable
, nspeculated
, nok
, nwrong
,
3327 nexternal
, nnotdefined
, nartificial
);
3328 return ndevirtualized
? TODO_remove_functions
: 0;
3333 const pass_data pass_data_ipa_devirt
=
3335 IPA_PASS
, /* type */
3336 "devirt", /* name */
3337 OPTGROUP_NONE
, /* optinfo_flags */
3338 TV_IPA_DEVIRT
, /* tv_id */
3339 0, /* properties_required */
3340 0, /* properties_provided */
3341 0, /* properties_destroyed */
3342 0, /* todo_flags_start */
3343 ( TODO_dump_symtab
), /* todo_flags_finish */
3346 class pass_ipa_devirt
: public ipa_opt_pass_d
3349 pass_ipa_devirt (gcc::context
*ctxt
)
3350 : ipa_opt_pass_d (pass_data_ipa_devirt
, ctxt
,
3351 NULL
, /* generate_summary */
3352 NULL
, /* write_summary */
3353 NULL
, /* read_summary */
3354 NULL
, /* write_optimization_summary */
3355 NULL
, /* read_optimization_summary */
3356 NULL
, /* stmt_fixup */
3357 0, /* function_transform_todo_flags_start */
3358 NULL
, /* function_transform */
3359 NULL
) /* variable_transform */
3362 /* opt_pass methods: */
3363 virtual bool gate (function
*)
3365 return (flag_devirtualize
3366 && (flag_devirtualize_speculatively
3367 || (warn_suggest_final_methods
3368 || warn_suggest_final_types
))
3372 virtual unsigned int execute (function
*) { return ipa_devirt (); }
3374 }; // class pass_ipa_devirt
3379 make_pass_ipa_devirt (gcc::context
*ctxt
)
3381 return new pass_ipa_devirt (ctxt
);
3384 #include "gt-ipa-devirt.h"