2 Copyright (C) 2003-2014 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file implements two related passes:
22 - pass_data_ipa_function_and_variable_visibility run just after
23 symbol table, references and callgraph are built
25 - pass_data_ipa_function_and_variable_visibility run as first
26 proper IPA pass (that is after early optimization, or, (with LTO)
27 as a first pass done at link-time.
29 Purpose of both passes is to set correctly visibility properties
30 of all symbols. This includes:
32 - Symbol privatization:
34 Some symbols that are declared public by frontend may be
35 turned local (either by -fwhole-program flag, by linker plugin feedback
38 - Discovery of local functions:
40 A local function is one whose calls can occur only in the current
41 compilation unit and all its calls are explicit, so we can change
42 its calling convention. We simply mark all static functions whose
43 address is not taken as local.
45 externally_visible flag is set for symbols that can not be privatized.
46 For privatized symbols we clear TREE_PUBLIC flag and dismantle comdat
49 - Dismantling of comdat groups:
51 Comdat group represent a section that may be replaced by linker by
52 a different copy of the same section from other unit.
53 If we have resolution information (from linker plugin) and we know that
54 a given comdat gorup is prevailing, we can dismantle it and turn symbols
55 into normal symbols. If the resolution information says that the
56 section was previaled by copy from non-LTO code, we can also dismantle
57 it and turn all symbols into external.
61 Some symbols can be interposed by dynamic linker. Refering to these
62 symbols is expensive, since it needs to be overwritable by the dynamic
63 linker. In some cases we know that the interposition does not change
64 semantic and we can always refer to a local copy (as in the case of
65 inline function). In this case we produce a local alias and redirect
68 TODO: This should be done for references, too.
70 - Removal of static ocnstructors and destructors that have no side effects.
72 - Regularization of several oddities introduced by frontends that may
73 be impractical later in the optimization queue. */
77 #include "coretypes.h"
82 #include "plugin-api.h"
87 #include "hard-reg-set.h"
92 #include "tree-pass.h"
94 #include "gimple-expr.h"
97 /* Return true when NODE can not be local. Worker for cgraph_local_node_p. */
100 cgraph_node::non_local_p (struct cgraph_node
*node
, void *data ATTRIBUTE_UNUSED
)
102 /* FIXME: Aliases can be local, but i386 gets thunks wrong then. */
103 return !(node
->only_called_directly_or_aliased_p ()
104 && !node
->has_aliases_p ()
106 && !DECL_EXTERNAL (node
->decl
)
107 && !node
->externally_visible
108 && !node
->used_from_other_partition
109 && !node
->in_other_partition
);
112 /* Return true when function can be marked local. */
115 cgraph_node::local_p (void)
117 cgraph_node
*n
= ultimate_alias_target ();
119 /* FIXME: thunks can be considered local, but we need prevent i386
120 from attempting to change calling convention of them. */
121 if (n
->thunk
.thunk_p
)
123 return !n
->call_for_symbol_thunks_and_aliases (cgraph_node::non_local_p
,
128 /* Return true when there is a reference to node and it is not vtable. */
131 symtab_node::address_taken_from_non_vtable_p (void)
134 struct ipa_ref
*ref
= NULL
;
136 for (i
= 0; iterate_referring (i
, ref
); i
++)
137 if (ref
->use
== IPA_REF_ADDR
)
140 if (is_a
<cgraph_node
*> (ref
->referring
))
142 node
= dyn_cast
<varpool_node
*> (ref
->referring
);
143 if (!DECL_VIRTUAL_P (node
->decl
))
149 /* A helper for comdat_can_be_unshared_p. */
152 comdat_can_be_unshared_p_1 (symtab_node
*node
)
154 if (!node
->externally_visible
)
156 /* When address is taken, we don't know if equality comparison won't
157 break eventually. Exception are virutal functions, C++
158 constructors/destructors and vtables, where this is not possible by
159 language standard. */
160 if (!DECL_VIRTUAL_P (node
->decl
)
161 && (TREE_CODE (node
->decl
) != FUNCTION_DECL
162 || (!DECL_CXX_CONSTRUCTOR_P (node
->decl
)
163 && !DECL_CXX_DESTRUCTOR_P (node
->decl
)))
164 && node
->address_taken_from_non_vtable_p ())
167 /* If the symbol is used in some weird way, better to not touch it. */
168 if (node
->force_output
)
171 /* Explicit instantiations needs to be output when possibly
173 if (node
->forced_by_abi
174 && TREE_PUBLIC (node
->decl
)
175 && (node
->resolution
!= LDPR_PREVAILING_DEF_IRONLY
176 && !flag_whole_program
))
179 /* Non-readonly and volatile variables can not be duplicated. */
180 if (is_a
<varpool_node
*> (node
)
181 && (!TREE_READONLY (node
->decl
)
182 || TREE_THIS_VOLATILE (node
->decl
)))
187 /* COMDAT functions must be shared only if they have address taken,
188 otherwise we can produce our own private implementation with
190 Return true when turning COMDAT functoin static can not lead to wrong
191 code when the resulting object links with a library defining same COMDAT.
193 Virtual functions do have their addresses taken from the vtables,
194 but in C++ there is no way to compare their addresses for equality. */
197 comdat_can_be_unshared_p (symtab_node
*node
)
199 if (!comdat_can_be_unshared_p_1 (node
))
201 if (node
->same_comdat_group
)
205 /* If more than one function is in the same COMDAT group, it must
206 be shared even if just one function in the comdat group has
208 for (next
= node
->same_comdat_group
;
209 next
!= node
; next
= next
->same_comdat_group
)
210 if (!comdat_can_be_unshared_p_1 (next
))
216 /* Return true when function NODE should be considered externally visible. */
219 cgraph_externally_visible_p (struct cgraph_node
*node
,
222 if (!node
->definition
)
224 if (!TREE_PUBLIC (node
->decl
)
225 || DECL_EXTERNAL (node
->decl
))
228 /* Do not try to localize built-in functions yet. One of problems is that we
229 end up mangling their asm for WHOPR that makes it impossible to call them
230 using the implicit built-in declarations anymore. Similarly this enables
231 us to remove them as unreachable before actual calls may appear during
232 expansion or folding. */
233 if (DECL_BUILT_IN (node
->decl
))
236 /* If linker counts on us, we must preserve the function. */
237 if (node
->used_from_object_file_p ())
239 if (DECL_PRESERVE_P (node
->decl
))
241 if (lookup_attribute ("externally_visible",
242 DECL_ATTRIBUTES (node
->decl
)))
244 if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
245 && lookup_attribute ("dllexport",
246 DECL_ATTRIBUTES (node
->decl
)))
248 if (node
->resolution
== LDPR_PREVAILING_DEF_IRONLY
)
250 /* When doing LTO or whole program, we can bring COMDAT functoins static.
251 This improves code quality and we know we will duplicate them at most twice
252 (in the case that we are not using plugin and link with object file
253 implementing same COMDAT) */
254 if ((in_lto_p
|| whole_program
)
255 && DECL_COMDAT (node
->decl
)
256 && comdat_can_be_unshared_p (node
))
259 /* When doing link time optimizations, hidden symbols become local. */
261 && (DECL_VISIBILITY (node
->decl
) == VISIBILITY_HIDDEN
262 || DECL_VISIBILITY (node
->decl
) == VISIBILITY_INTERNAL
)
263 /* Be sure that node is defined in IR file, not in other object
264 file. In that case we don't set used_from_other_object_file. */
267 else if (!whole_program
)
270 if (MAIN_NAME_P (DECL_NAME (node
->decl
)))
276 /* Return true when variable should be considered externally visible. */
279 varpool_node::externally_visible_p (void)
281 if (DECL_EXTERNAL (decl
))
284 if (!TREE_PUBLIC (decl
))
287 /* If linker counts on us, we must preserve the function. */
288 if (used_from_object_file_p ())
291 /* Bringing TLS variables local may cause dynamic linker failures
292 on limits of static TLS vars. */
293 if (DECL_THREAD_LOCAL_P (decl
)
294 && (DECL_TLS_MODEL (decl
) != TLS_MODEL_EMULATED
295 && DECL_TLS_MODEL (decl
) != TLS_MODEL_INITIAL_EXEC
))
298 if (DECL_HARD_REGISTER (decl
))
300 if (DECL_PRESERVE_P (decl
))
302 if (lookup_attribute ("externally_visible",
303 DECL_ATTRIBUTES (decl
)))
305 if (TARGET_DLLIMPORT_DECL_ATTRIBUTES
306 && lookup_attribute ("dllexport",
307 DECL_ATTRIBUTES (decl
)))
310 /* See if we have linker information about symbol not being used or
311 if we need to make guess based on the declaration.
313 Even if the linker clams the symbol is unused, never bring internal
314 symbols that are declared by user as used or externally visible.
315 This is needed for i.e. references from asm statements. */
316 if (used_from_object_file_p ())
318 if (resolution
== LDPR_PREVAILING_DEF_IRONLY
)
321 /* As a special case, the COMDAT virtual tables can be unshared.
322 In LTO mode turn vtables into static variables. The variable is readonly,
323 so this does not enable more optimization, but referring static var
324 is faster for dynamic linking. Also this match logic hidding vtables
325 from LTO symbol tables. */
326 if ((in_lto_p
|| flag_whole_program
)
327 && DECL_COMDAT (decl
)
328 && comdat_can_be_unshared_p (this))
331 /* When doing link time optimizations, hidden symbols become local. */
333 && (DECL_VISIBILITY (decl
) == VISIBILITY_HIDDEN
334 || DECL_VISIBILITY (decl
) == VISIBILITY_INTERNAL
)
335 /* Be sure that node is defined in IR file, not in other object
336 file. In that case we don't set used_from_other_object_file. */
339 else if (!flag_whole_program
)
342 /* Do not attempt to privatize COMDATS by default.
343 This would break linking with C++ libraries sharing
346 FIXME: We can do so for readonly vars with no address taken and
347 possibly also for vtables since no direct pointer comparsion is done.
348 It might be interesting to do so to reduce linking overhead. */
349 if (DECL_COMDAT (decl
) || DECL_WEAK (decl
))
354 /* Return true if reference to NODE can be replaced by a local alias.
355 Local aliases save dynamic linking overhead and enable more optimizations.
359 can_replace_by_local_alias (symtab_node
*node
)
361 return (node
->get_availability () > AVAIL_INTERPOSABLE
362 && !decl_binds_to_current_def_p (node
->decl
)
363 && !node
->can_be_discarded_p ());
366 /* Return true if we can replace refernece to NODE by local alias
367 within a virtual table. Generally we can replace function pointers
368 and virtual table pointers. */
371 can_replace_by_local_alias_in_vtable (symtab_node
*node
)
373 if (is_a
<varpool_node
*> (node
)
374 && !DECL_VIRTUAL_P (node
->decl
))
376 return can_replace_by_local_alias (node
);
379 /* walk_tree callback that rewrites initializer references. */
382 update_vtable_references (tree
*tp
, int *walk_subtrees
, void *data ATTRIBUTE_UNUSED
)
384 if (TREE_CODE (*tp
) == VAR_DECL
385 || TREE_CODE (*tp
) == FUNCTION_DECL
)
387 if (can_replace_by_local_alias_in_vtable (symtab_node::get (*tp
)))
388 *tp
= symtab_node::get (*tp
)->noninterposable_alias ()->decl
;
391 else if (IS_TYPE_OR_DECL_P (*tp
))
396 /* In LTO we can remove COMDAT groups and weak symbols.
397 Either turn them into normal symbols or external symbol depending on
401 update_visibility_by_resolution_info (symtab_node
* node
)
405 if (!node
->externally_visible
406 || (!DECL_WEAK (node
->decl
) && !DECL_ONE_ONLY (node
->decl
))
407 || node
->resolution
== LDPR_UNKNOWN
)
410 define
= (node
->resolution
== LDPR_PREVAILING_DEF_IRONLY
411 || node
->resolution
== LDPR_PREVAILING_DEF
412 || node
->resolution
== LDPR_UNDEF
413 || node
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
);
415 /* The linker decisions ought to agree in the whole group. */
416 if (node
->same_comdat_group
)
417 for (symtab_node
*next
= node
->same_comdat_group
;
418 next
!= node
; next
= next
->same_comdat_group
)
419 gcc_assert (!next
->externally_visible
420 || define
== (next
->resolution
== LDPR_PREVAILING_DEF_IRONLY
421 || next
->resolution
== LDPR_PREVAILING_DEF
422 || next
->resolution
== LDPR_UNDEF
423 || next
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
));
425 if (node
->same_comdat_group
)
426 for (symtab_node
*next
= node
->same_comdat_group
;
427 next
!= node
; next
= next
->same_comdat_group
)
429 next
->set_comdat_group (NULL
);
430 DECL_WEAK (next
->decl
) = false;
431 if (next
->externally_visible
433 DECL_EXTERNAL (next
->decl
) = true;
435 node
->set_comdat_group (NULL
);
436 DECL_WEAK (node
->decl
) = false;
438 DECL_EXTERNAL (node
->decl
) = true;
439 node
->dissolve_same_comdat_group_list ();
442 /* Decide on visibility of all symbols. */
445 function_and_variable_visibility (bool whole_program
)
447 struct cgraph_node
*node
;
450 /* All aliases should be procssed at this point. */
451 gcc_checking_assert (!alias_pairs
|| !alias_pairs
->length ());
453 FOR_EACH_FUNCTION (node
)
455 int flags
= flags_from_decl_or_type (node
->decl
);
457 /* Optimize away PURE and CONST constructors and destructors. */
459 && (flags
& (ECF_CONST
| ECF_PURE
))
460 && !(flags
& ECF_LOOPING_CONST_OR_PURE
))
462 DECL_STATIC_CONSTRUCTOR (node
->decl
) = 0;
463 DECL_STATIC_DESTRUCTOR (node
->decl
) = 0;
466 /* Frontends and alias code marks nodes as needed before parsing is finished.
467 We may end up marking as node external nodes where this flag is meaningless
469 if (DECL_EXTERNAL (node
->decl
) || !node
->definition
)
471 node
->force_output
= 0;
472 node
->forced_by_abi
= 0;
475 /* C++ FE on lack of COMDAT support create local COMDAT functions
476 (that ought to be shared but can not due to object format
477 limitations). It is necessary to keep the flag to make rest of C++ FE
478 happy. Clear the flag here to avoid confusion in middle-end. */
479 if (DECL_COMDAT (node
->decl
) && !TREE_PUBLIC (node
->decl
))
480 DECL_COMDAT (node
->decl
) = 0;
482 /* For external decls stop tracking same_comdat_group. It doesn't matter
483 what comdat group they are in when they won't be emitted in this TU. */
484 if (node
->same_comdat_group
&& DECL_EXTERNAL (node
->decl
))
486 #ifdef ENABLE_CHECKING
489 for (n
= node
->same_comdat_group
;
491 n
= n
->same_comdat_group
)
492 /* If at least one of same comdat group functions is external,
493 all of them have to be, otherwise it is a front-end bug. */
494 gcc_assert (DECL_EXTERNAL (n
->decl
));
496 node
->dissolve_same_comdat_group_list ();
498 gcc_assert ((!DECL_WEAK (node
->decl
)
499 && !DECL_COMDAT (node
->decl
))
500 || TREE_PUBLIC (node
->decl
)
502 || DECL_EXTERNAL (node
->decl
));
503 if (cgraph_externally_visible_p (node
, whole_program
))
505 gcc_assert (!node
->global
.inlined_to
);
506 node
->externally_visible
= true;
510 node
->externally_visible
= false;
511 node
->forced_by_abi
= false;
513 if (!node
->externally_visible
514 && node
->definition
&& !node
->weakref
515 && !DECL_EXTERNAL (node
->decl
))
517 gcc_assert (whole_program
|| in_lto_p
518 || !TREE_PUBLIC (node
->decl
));
519 node
->unique_name
= ((node
->resolution
== LDPR_PREVAILING_DEF_IRONLY
521 || node
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
)
522 && TREE_PUBLIC (node
->decl
));
523 node
->resolution
= LDPR_PREVAILING_DEF_IRONLY
;
524 if (node
->same_comdat_group
&& TREE_PUBLIC (node
->decl
))
526 symtab_node
*next
= node
;
528 /* Set all members of comdat group local. */
529 if (node
->same_comdat_group
)
530 for (next
= node
->same_comdat_group
;
532 next
= next
->same_comdat_group
)
534 next
->set_comdat_group (NULL
);
536 next
->set_section (NULL
);
537 next
->make_decl_local ();
538 next
->unique_name
= ((next
->resolution
== LDPR_PREVAILING_DEF_IRONLY
540 || next
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
)
541 && TREE_PUBLIC (next
->decl
));
543 /* cgraph_externally_visible_p has already checked all other nodes
544 in the group and they will all be made local. We need to
545 dissolve the group at once so that the predicate does not
547 node
->dissolve_same_comdat_group_list ();
549 if (TREE_PUBLIC (node
->decl
))
550 node
->set_comdat_group (NULL
);
551 if (DECL_COMDAT (node
->decl
) && !node
->alias
)
552 node
->set_section (NULL
);
553 node
->make_decl_local ();
556 if (node
->thunk
.thunk_p
557 && TREE_PUBLIC (node
->decl
))
559 struct cgraph_node
*decl_node
= node
;
561 decl_node
= decl_node
->callees
->callee
->function_symbol ();
563 /* Thunks have the same visibility as function they are attached to.
564 Make sure the C++ front end set this up properly. */
565 if (DECL_ONE_ONLY (decl_node
->decl
))
567 gcc_checking_assert (DECL_COMDAT (node
->decl
)
568 == DECL_COMDAT (decl_node
->decl
));
569 gcc_checking_assert (node
->in_same_comdat_group_p (decl_node
));
570 gcc_checking_assert (node
->same_comdat_group
);
572 node
->forced_by_abi
= decl_node
->forced_by_abi
;
573 if (DECL_EXTERNAL (decl_node
->decl
))
574 DECL_EXTERNAL (node
->decl
) = 1;
577 update_visibility_by_resolution_info (node
);
579 FOR_EACH_DEFINED_FUNCTION (node
)
581 node
->local
.local
|= node
->local_p ();
583 /* If we know that function can not be overwritten by a different semantics
584 and moreover its section can not be discarded, replace all direct calls
585 by calls to an noninterposable alias. This make dynamic linking
586 cheaper and enable more optimization.
588 TODO: We can also update virtual tables. */
590 && can_replace_by_local_alias (node
))
592 cgraph_node
*alias
= dyn_cast
<cgraph_node
*>
593 (node
->noninterposable_alias ());
595 if (alias
&& alias
!= node
)
597 while (node
->callers
)
599 struct cgraph_edge
*e
= node
->callers
;
601 e
->redirect_callee (alias
);
602 if (gimple_has_body_p (e
->caller
->decl
))
604 push_cfun (DECL_STRUCT_FUNCTION (e
->caller
->decl
));
605 e
->redirect_call_stmt_to_callee ();
612 FOR_EACH_VARIABLE (vnode
)
614 /* weak flag makes no sense on local variables. */
615 gcc_assert (!DECL_WEAK (vnode
->decl
)
617 || TREE_PUBLIC (vnode
->decl
)
618 || DECL_EXTERNAL (vnode
->decl
));
619 /* In several cases declarations can not be common:
621 - when declaration has initializer
623 - when it has specific section
624 - when it resides in non-generic address space.
625 - if declaration is local, it will get into .local common section
626 so common flag is not needed. Frontends still produce these in
627 certain cases, such as for:
629 static int a __attribute__ ((common))
631 Canonicalize things here and clear the redundant flag. */
632 if (DECL_COMMON (vnode
->decl
)
633 && (!(TREE_PUBLIC (vnode
->decl
)
634 || DECL_EXTERNAL (vnode
->decl
))
635 || (DECL_INITIAL (vnode
->decl
)
636 && DECL_INITIAL (vnode
->decl
) != error_mark_node
)
637 || DECL_WEAK (vnode
->decl
)
638 || DECL_SECTION_NAME (vnode
->decl
) != NULL
639 || ! (ADDR_SPACE_GENERIC_P
640 (TYPE_ADDR_SPACE (TREE_TYPE (vnode
->decl
))))))
641 DECL_COMMON (vnode
->decl
) = 0;
643 FOR_EACH_DEFINED_VARIABLE (vnode
)
645 if (!vnode
->definition
)
647 if (vnode
->externally_visible_p ())
648 vnode
->externally_visible
= true;
651 vnode
->externally_visible
= false;
652 vnode
->forced_by_abi
= false;
654 if (lookup_attribute ("no_reorder",
655 DECL_ATTRIBUTES (vnode
->decl
)))
656 vnode
->no_reorder
= 1;
657 if (!vnode
->externally_visible
660 gcc_assert (in_lto_p
|| whole_program
|| !TREE_PUBLIC (vnode
->decl
));
661 vnode
->unique_name
= ((vnode
->resolution
== LDPR_PREVAILING_DEF_IRONLY
662 || vnode
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
)
663 && TREE_PUBLIC (vnode
->decl
));
664 if (vnode
->same_comdat_group
&& TREE_PUBLIC (vnode
->decl
))
666 symtab_node
*next
= vnode
;
668 /* Set all members of comdat group local. */
669 if (vnode
->same_comdat_group
)
670 for (next
= vnode
->same_comdat_group
;
672 next
= next
->same_comdat_group
)
674 next
->set_comdat_group (NULL
);
676 next
->set_section (NULL
);
677 next
->make_decl_local ();
678 next
->unique_name
= ((next
->resolution
== LDPR_PREVAILING_DEF_IRONLY
680 || next
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
)
681 && TREE_PUBLIC (next
->decl
));
683 vnode
->dissolve_same_comdat_group_list ();
685 if (TREE_PUBLIC (vnode
->decl
))
686 vnode
->set_comdat_group (NULL
);
687 if (DECL_COMDAT (vnode
->decl
) && !vnode
->alias
)
688 vnode
->set_section (NULL
);
689 vnode
->make_decl_local ();
690 vnode
->resolution
= LDPR_PREVAILING_DEF_IRONLY
;
692 update_visibility_by_resolution_info (vnode
);
694 /* Update virtual tables to point to local aliases where possible. */
695 if (DECL_VIRTUAL_P (vnode
->decl
)
696 && !DECL_EXTERNAL (vnode
->decl
))
702 /* See if there is something to update. */
703 for (i
= 0; vnode
->iterate_referring (i
, ref
); i
++)
704 if (ref
->use
== IPA_REF_ADDR
705 && can_replace_by_local_alias_in_vtable (ref
->referred
))
712 hash_set
<tree
> visited_nodes
;
714 vnode
->get_constructor ();
715 walk_tree (&DECL_INITIAL (vnode
->decl
),
716 update_vtable_references
, NULL
, &visited_nodes
);
717 vnode
->remove_all_references ();
718 record_references_in_initializer (vnode
->decl
, false);
725 fprintf (dump_file
, "\nMarking local functions:");
726 FOR_EACH_DEFINED_FUNCTION (node
)
727 if (node
->local
.local
)
728 fprintf (dump_file
, " %s", node
->name ());
729 fprintf (dump_file
, "\n\n");
730 fprintf (dump_file
, "\nMarking externally visible functions:");
731 FOR_EACH_DEFINED_FUNCTION (node
)
732 if (node
->externally_visible
)
733 fprintf (dump_file
, " %s", node
->name ());
734 fprintf (dump_file
, "\n\n");
735 fprintf (dump_file
, "\nMarking externally visible variables:");
736 FOR_EACH_DEFINED_VARIABLE (vnode
)
737 if (vnode
->externally_visible
)
738 fprintf (dump_file
, " %s", vnode
->name ());
739 fprintf (dump_file
, "\n\n");
741 symtab
->function_flags_ready
= true;
745 /* Local function pass handling visibilities. This happens before LTO streaming
746 so in particular -fwhole-program should be ignored at this level. */
750 const pass_data pass_data_ipa_function_and_variable_visibility
=
752 SIMPLE_IPA_PASS
, /* type */
753 "visibility", /* name */
754 OPTGROUP_NONE
, /* optinfo_flags */
755 TV_CGRAPHOPT
, /* tv_id */
756 0, /* properties_required */
757 0, /* properties_provided */
758 0, /* properties_destroyed */
759 0, /* todo_flags_start */
760 ( TODO_remove_functions
| TODO_dump_symtab
), /* todo_flags_finish */
763 /* Bring functions local at LTO time with -fwhole-program. */
766 whole_program_function_and_variable_visibility (void)
768 function_and_variable_visibility (flag_whole_program
);
770 ipa_discover_readonly_nonaddressable_vars ();
778 const pass_data pass_data_ipa_whole_program_visibility
=
781 "whole-program", /* name */
782 OPTGROUP_NONE
, /* optinfo_flags */
783 TV_CGRAPHOPT
, /* tv_id */
784 0, /* properties_required */
785 0, /* properties_provided */
786 0, /* properties_destroyed */
787 0, /* todo_flags_start */
788 ( TODO_remove_functions
| TODO_dump_symtab
), /* todo_flags_finish */
791 class pass_ipa_whole_program_visibility
: public ipa_opt_pass_d
794 pass_ipa_whole_program_visibility (gcc::context
*ctxt
)
795 : ipa_opt_pass_d (pass_data_ipa_whole_program_visibility
, ctxt
,
796 NULL
, /* generate_summary */
797 NULL
, /* write_summary */
798 NULL
, /* read_summary */
799 NULL
, /* write_optimization_summary */
800 NULL
, /* read_optimization_summary */
801 NULL
, /* stmt_fixup */
802 0, /* function_transform_todo_flags_start */
803 NULL
, /* function_transform */
804 NULL
) /* variable_transform */
807 /* opt_pass methods: */
809 virtual bool gate (function
*)
811 /* Do not re-run on ltrans stage. */
814 virtual unsigned int execute (function
*)
816 return whole_program_function_and_variable_visibility ();
819 }; // class pass_ipa_whole_program_visibility
824 make_pass_ipa_whole_program_visibility (gcc::context
*ctxt
)
826 return new pass_ipa_whole_program_visibility (ctxt
);
829 class pass_ipa_function_and_variable_visibility
: public simple_ipa_opt_pass
832 pass_ipa_function_and_variable_visibility (gcc::context
*ctxt
)
833 : simple_ipa_opt_pass (pass_data_ipa_function_and_variable_visibility
,
837 /* opt_pass methods: */
838 virtual unsigned int execute (function
*)
840 return function_and_variable_visibility (flag_whole_program
&& !flag_lto
);
843 }; // class pass_ipa_function_and_variable_visibility
845 simple_ipa_opt_pass
*
846 make_pass_ipa_function_and_variable_visibility (gcc::context
*ctxt
)
848 return new pass_ipa_function_and_variable_visibility (ctxt
);