1 /* Type based alias analysis.
2 Copyright (C) 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
22 /* This pass determines which types in the program contain only
23 instances that are completely encapsulated by the compilation unit.
24 Those types that are encapsulated must also pass the further
25 requirement that there be no bad operations on any instances of
28 A great deal of freedom in compilation is allowed for the instances
29 of those types that pass these conditions.
32 /* The code in this module is called by the ipa pass manager. It
33 should be one of the later passes since its information is used by
34 the rest of the compilation. */
38 #include "coretypes.h"
41 #include "tree-flow.h"
42 #include "tree-inline.h"
43 #include "tree-pass.h"
44 #include "langhooks.h"
45 #include "pointer-set.h"
47 #include "ipa-utils.h"
48 #include "ipa-type-escape.h"
50 #include "tree-gimple.h"
55 #include "diagnostic.h"
56 #include "langhooks.h"
58 /* Some of the aliasing is called very early, before this phase is
59 called. To assure that this is not a problem, we keep track of if
60 this phase has been run. */
61 static bool initialized
= false;
63 /* This bitmap contains the set of local vars that are the lhs of
64 calls to mallocs. These variables, when seen on the rhs as part of
65 a cast, the cast are not marked as doing bad things to the type
66 even though they are generally of the form
67 "foo = (type_of_foo)void_temp". */
68 static bitmap results_of_malloc
;
70 /* Scratch bitmap for avoiding work. */
71 static bitmap been_there_done_that
;
72 static bitmap bitmap_tmp
;
74 /* There are two levels of escape that types can undergo.
76 EXPOSED_PARAMETER - some instance of the variable is
77 passed by value into an externally visible function or some
78 instance of the variable is passed out of an externally visible
79 function as a return value. In this case any of the fields of the
80 variable that are pointer types end up having their types marked as
83 FULL_ESCAPE - when bad things happen to good types. One of the
84 following things happens to the type: (a) either an instance of the
85 variable has its address passed to an externally visible function,
86 (b) the address is taken and some bad cast happens to the address
87 or (c) explicit arithmetic is done to the address.
96 /* The following two bit vectors global_types_* correspond to
97 previous cases above. During the analysis phase, a bit is set in
98 one of these vectors if an operation of the offending class is
99 discovered to happen on the associated type. */
101 static bitmap global_types_exposed_parameter
;
102 static bitmap global_types_full_escape
;
104 /* All of the types seen in this compilation unit. */
105 static bitmap global_types_seen
;
106 /* Reverse map to take a canon uid and map it to a canon type. Uid's
107 are never manipulated unless they are associated with a canon
109 static splay_tree uid_to_canon_type
;
111 /* Internal structure of type mapping code. This maps a canon type
112 name to its canon type. */
113 static splay_tree all_canon_types
;
115 /* Map from type clones to the single canon type. */
116 static splay_tree type_to_canon_type
;
118 /* A splay tree of bitmaps. An element X in the splay tree has a bit
119 set in its bitmap at TYPE_UID (TYPE_MAIN_VARIANT (Y)) if there was
120 an operation in the program of the form "&X.Y". */
121 static splay_tree uid_to_addressof_down_map
;
123 /* A splay tree of bitmaps. An element Y in the splay tree has a bit
124 set in its bitmap at TYPE_UID (TYPE_MAIN_VARIANT (X)) if there was
125 an operation in the program of the form "&X.Y". */
126 static splay_tree uid_to_addressof_up_map
;
128 /* Tree to hold the subtype maps used to mark subtypes of escaped
130 static splay_tree uid_to_subtype_map
;
132 /* Records tree nodes seen in cgraph_create_edges. Simply using
133 walk_tree_without_duplicates doesn't guarantee each node is visited
134 once because it gets a new htab upon each recursive call from
136 static struct pointer_set_t
*visited_nodes
;
138 static bitmap_obstack ipa_obstack
;
140 /* Get the name of TYPE or return the string "<UNNAMED>". */
142 get_name_of_type (tree type
)
144 tree name
= TYPE_NAME (type
);
147 /* Unnamed type, do what you like here. */
148 return (char*)"<UNNAMED>";
150 /* It will be a TYPE_DECL in the case of a typedef, otherwise, an
152 if (TREE_CODE (name
) == TYPE_DECL
)
154 /* Each DECL has a DECL_NAME field which contains an
155 IDENTIFIER_NODE. (Some decls, most often labels, may have
156 zero as the DECL_NAME). */
157 if (DECL_NAME (name
))
158 return (char*)IDENTIFIER_POINTER (DECL_NAME (name
));
160 /* Unnamed type, do what you like here. */
161 return (char*)"<UNNAMED>";
163 else if (TREE_CODE (name
) == IDENTIFIER_NODE
)
164 return (char*)IDENTIFIER_POINTER (name
);
166 return (char*)"<UNNAMED>";
175 /* Splay tree comparison function on type_brand_s structures. */
178 compare_type_brand (splay_tree_key sk1
, splay_tree_key sk2
)
180 struct type_brand_s
* k1
= (struct type_brand_s
*) sk1
;
181 struct type_brand_s
* k2
= (struct type_brand_s
*) sk2
;
183 int value
= strcmp(k1
->name
, k2
->name
);
185 return k2
->seq
- k1
->seq
;
190 /* All of the "unique_type" code is a hack to get around the sleazy
191 implementation used to compile more than file. Currently gcc does
192 not get rid of multiple instances of the same type that have been
193 collected from different compilation units. */
194 /* This is a trivial algorithm for removing duplicate types. This
195 would not work for any language that used structural equivalence as
196 the basis of its type system. */
197 /* Return either TYPE if this is first time TYPE has been seen an
198 compatible TYPE that has already been processed. */
201 discover_unique_type (tree type
)
203 struct type_brand_s
* brand
= xmalloc (sizeof (struct type_brand_s
));
205 splay_tree_node result
;
207 brand
->name
= get_name_of_type (type
);
212 result
= splay_tree_lookup (all_canon_types
, (splay_tree_key
) brand
);
216 /* Create an alias since this is just the same as
218 tree other_type
= (tree
) result
->value
;
219 if (lang_hooks
.types_compatible_p (type
, other_type
) == 1)
222 /* Insert this new type as an alias for other_type. */
223 splay_tree_insert (type_to_canon_type
,
224 (splay_tree_key
) type
,
225 (splay_tree_value
) other_type
);
228 /* Not compatible, look for next instance with same name. */
232 /* No more instances, create new one since this is the first
233 time we saw this type. */
235 /* Insert the new brand. */
236 splay_tree_insert (all_canon_types
,
237 (splay_tree_key
) brand
,
238 (splay_tree_value
) type
);
240 /* Insert this new type as an alias for itself. */
241 splay_tree_insert (type_to_canon_type
,
242 (splay_tree_key
) type
,
243 (splay_tree_value
) type
);
245 /* Insert the uid for reverse lookup; */
246 splay_tree_insert (uid_to_canon_type
,
247 (splay_tree_key
) TYPE_UID (type
),
248 (splay_tree_value
) type
);
250 bitmap_set_bit (global_types_seen
, TYPE_UID (type
));
256 /* Return true if TYPE is one of the type classes that we are willing
257 to analyze. This skips the goofy types like arrays of pointers to
260 type_to_consider (tree type
)
262 /* Strip the *'s off. */
263 type
= TYPE_MAIN_VARIANT (type
);
264 while (POINTER_TYPE_P (type
) || TREE_CODE (type
) == ARRAY_TYPE
)
265 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
267 switch (TREE_CODE (type
))
274 case QUAL_UNION_TYPE
:
287 /* Get the canon type of TYPE. If SEE_THRU_PTRS is true, remove all
288 the POINTER_TOs and if SEE_THRU_ARRAYS is true, remove all of the
289 ARRAY_OFs and POINTER_TOs. */
292 get_canon_type (tree type
, bool see_thru_ptrs
, bool see_thru_arrays
)
294 splay_tree_node result
;
295 /* Strip the *'s off. */
296 if (!type
|| !type_to_consider (type
))
299 type
= TYPE_MAIN_VARIANT (type
);
301 while (POINTER_TYPE_P (type
) || TREE_CODE (type
) == ARRAY_TYPE
)
302 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
304 else if (see_thru_ptrs
)
305 while (POINTER_TYPE_P (type
))
306 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
308 result
= splay_tree_lookup(type_to_canon_type
, (splay_tree_key
) type
);
311 return discover_unique_type (type
);
312 else return (tree
) result
->value
;
315 /* Same as GET_CANON_TYPE, except return the TYPE_ID rather than the
319 get_canon_type_uid (tree type
, bool see_thru_ptrs
, bool see_thru_arrays
)
321 type
= get_canon_type (type
, see_thru_ptrs
, see_thru_arrays
);
323 return TYPE_UID(type
);
327 /* Return 0 if TYPE is a record or union type. Return a positive
328 number if TYPE is a pointer to a record or union. The number is
329 the number of pointer types stripped to get to the record or union
330 type. Return -1 if TYPE is none of the above. */
333 ipa_type_escape_star_count_of_interesting_type (tree type
)
336 /* Strip the *'s off. */
339 type
= TYPE_MAIN_VARIANT (type
);
340 while (POINTER_TYPE_P (type
))
342 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
346 /* We are interested in records, and unions only. */
347 if (TREE_CODE (type
) == RECORD_TYPE
348 || TREE_CODE (type
) == QUAL_UNION_TYPE
349 || TREE_CODE (type
) == UNION_TYPE
)
356 /* Return 0 if TYPE is a record or union type. Return a positive
357 number if TYPE is a pointer to a record or union. The number is
358 the number of pointer types stripped to get to the record or union
359 type. Return -1 if TYPE is none of the above. */
362 ipa_type_escape_star_count_of_interesting_or_array_type (tree type
)
365 /* Strip the *'s off. */
368 type
= TYPE_MAIN_VARIANT (type
);
369 while (POINTER_TYPE_P (type
) || TREE_CODE (type
) == ARRAY_TYPE
)
371 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
375 /* We are interested in records, and unions only. */
376 if (TREE_CODE (type
) == RECORD_TYPE
377 || TREE_CODE (type
) == QUAL_UNION_TYPE
378 || TREE_CODE (type
) == UNION_TYPE
)
385 /* Return true if the record, or union TYPE passed in escapes this
386 compilation unit. Note that all of the pointer-to's are removed
387 before testing since these may not be correct. */
390 ipa_type_escape_type_contained_p (tree type
)
394 return !bitmap_bit_p (global_types_full_escape
,
395 get_canon_type_uid (type
, true, false));
398 /* Return true a modification to a field of type FIELD_TYPE cannot
399 clobber a record of RECORD_TYPE. */
402 ipa_type_escape_field_does_not_clobber_p (tree record_type
, tree field_type
)
404 splay_tree_node result
;
410 /* Strip off all of the pointer tos on the record type. Strip the
411 same number of pointer tos from the field type. If the field
412 type has fewer, it could not have been aliased. */
413 record_type
= TYPE_MAIN_VARIANT (record_type
);
414 field_type
= TYPE_MAIN_VARIANT (field_type
);
415 while (POINTER_TYPE_P (record_type
))
417 record_type
= TYPE_MAIN_VARIANT (TREE_TYPE (record_type
));
418 if (POINTER_TYPE_P (field_type
))
419 field_type
= TYPE_MAIN_VARIANT (TREE_TYPE (field_type
));
421 /* However, if field_type is a union, this quick test is not
422 correct since one of the variants of the union may be a
423 pointer to type and we cannot see across that here. So we
424 just strip the remaining pointer tos off the record type
425 and fall thru to the more precise code. */
426 if (TREE_CODE (field_type
) == QUAL_UNION_TYPE
427 || TREE_CODE (field_type
) == UNION_TYPE
)
429 while (POINTER_TYPE_P (record_type
))
430 record_type
= TYPE_MAIN_VARIANT (TREE_TYPE (record_type
));
437 record_type
= get_canon_type (record_type
, true, true);
438 /* The record type must be contained. The field type may
440 if (!ipa_type_escape_type_contained_p (record_type
))
443 uid
= TYPE_UID (record_type
);
444 result
= splay_tree_lookup (uid_to_addressof_down_map
, (splay_tree_key
) uid
);
448 bitmap field_type_map
= (bitmap
) result
->value
;
449 uid
= get_canon_type_uid (field_type
, true, true);
450 /* If the bit is there, the address was taken. If not, it
452 return !bitmap_bit_p (field_type_map
, uid
);
455 /* No bitmap means no addresses were taken. */
460 /* Add TYPE to the suspect type set. Return true if the bit needed to
464 mark_type (tree type
, enum escape_t escape_status
)
469 type
= get_canon_type (type
, true, true);
473 switch (escape_status
)
475 case EXPOSED_PARAMETER
:
476 map
= global_types_exposed_parameter
;
479 map
= global_types_full_escape
;
483 uid
= TYPE_UID (type
);
484 if (bitmap_bit_p (map
, uid
))
488 bitmap_set_bit (map
, uid
);
489 if (escape_status
== FULL_ESCAPE
)
491 /* Efficiency hack. When things are bad, do not mess around
492 with this type anymore. */
493 bitmap_set_bit (global_types_exposed_parameter
, uid
);
499 /* Add interesting TYPE to the suspect type set. If the set is
500 EXPOSED_PARAMETER and the TYPE is a pointer type, the set is
501 changed to FULL_ESCAPE. */
504 mark_interesting_type (tree type
, enum escape_t escape_status
)
507 if (ipa_type_escape_star_count_of_interesting_type (type
) >= 0)
509 if ((escape_status
== EXPOSED_PARAMETER
)
510 && POINTER_TYPE_P (type
))
511 /* EXPOSED_PARAMETERs are only structs or unions are passed by
512 value. Anything passed by reference to an external
513 function fully exposes the type. */
514 mark_type (type
, FULL_ESCAPE
);
516 mark_type (type
, escape_status
);
520 /* Return true if PARENT is supertype of CHILD. Both types must be
521 known to be structures or unions. */
524 parent_type_p (tree parent
, tree child
)
527 tree binfo
, base_binfo
;
528 if (TYPE_BINFO (parent
))
529 for (binfo
= TYPE_BINFO (parent
), i
= 0;
530 BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
532 tree binfotype
= BINFO_TYPE (base_binfo
);
533 if (binfotype
== child
)
535 else if (parent_type_p (binfotype
, child
))
538 if (TREE_CODE (parent
) == UNION_TYPE
539 || TREE_CODE (parent
) == QUAL_UNION_TYPE
)
542 /* Search all of the variants in the union to see if one of them
544 for (field
= TYPE_FIELDS (parent
);
546 field
= TREE_CHAIN (field
))
549 if (TREE_CODE (field
) != FIELD_DECL
)
552 field_type
= TREE_TYPE (field
);
553 if (field_type
== child
)
557 /* If we did not find it, recursively ask the variants if one of
558 their children is the child type. */
559 for (field
= TYPE_FIELDS (parent
);
561 field
= TREE_CHAIN (field
))
564 if (TREE_CODE (field
) != FIELD_DECL
)
567 field_type
= TREE_TYPE (field
);
568 if (TREE_CODE (field_type
) == RECORD_TYPE
569 || TREE_CODE (field_type
) == QUAL_UNION_TYPE
570 || TREE_CODE (field_type
) == UNION_TYPE
)
571 if (parent_type_p (field_type
, child
))
576 if (TREE_CODE (parent
) == RECORD_TYPE
)
579 for (field
= TYPE_FIELDS (parent
);
581 field
= TREE_CHAIN (field
))
584 if (TREE_CODE (field
) != FIELD_DECL
)
587 field_type
= TREE_TYPE (field
);
588 if (field_type
== child
)
590 /* You can only cast to the first field so if it does not
592 if (TREE_CODE (field_type
) == RECORD_TYPE
593 || TREE_CODE (field_type
) == QUAL_UNION_TYPE
594 || TREE_CODE (field_type
) == UNION_TYPE
)
596 if (parent_type_p (field_type
, child
))
606 /* Return the number of pointer tos for TYPE and return TYPE with all
607 of these stripped off. */
610 count_stars (tree
* type_ptr
)
612 tree type
= *type_ptr
;
614 type
= TYPE_MAIN_VARIANT (type
);
615 while (POINTER_TYPE_P (type
))
617 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
632 /* Check the cast FROM_TYPE to TO_TYPE. This function requires that
633 the two types have already passed the
634 ipa_type_escape_star_count_of_interesting_type test. */
636 static enum cast_type
637 check_cast_type (tree to_type
, tree from_type
)
639 int to_stars
= count_stars (&to_type
);
640 int from_stars
= count_stars (&from_type
);
641 if (to_stars
!= from_stars
)
644 if (to_type
== from_type
)
647 if (parent_type_p (to_type
, from_type
)) return CT_UP
;
648 if (parent_type_p (from_type
, to_type
)) return CT_DOWN
;
652 /* Check a cast FROM this variable, TO_TYPE. Mark the escaping types
655 check_cast (tree to_type
, tree from
)
657 tree from_type
= get_canon_type (TREE_TYPE (from
), false, false);
658 bool to_interesting_type
, from_interesting_type
;
660 to_type
= get_canon_type (to_type
, false, false);
661 if (!from_type
|| !to_type
|| from_type
== to_type
)
664 to_interesting_type
=
665 ipa_type_escape_star_count_of_interesting_type (to_type
) >= 0;
666 from_interesting_type
=
667 ipa_type_escape_star_count_of_interesting_type (from_type
) >= 0;
669 if (to_interesting_type
)
670 if (from_interesting_type
)
672 /* Both types are interesting. This can be one of four types
673 of cast: useless, up, down, or sideways. We do not care
674 about up or useless. Sideways casts are always bad and
675 both sides get marked as escaping. Downcasts are not
676 interesting here because if type is marked as escaping, all
677 of its subtypes escape. */
678 switch (check_cast_type (to_type
, from_type
))
686 mark_type (to_type
, FULL_ESCAPE
);
687 mark_type (from_type
, FULL_ESCAPE
);
693 /* If this is a cast from the local that is a result from a
694 call to malloc, do not mark the cast as bad. */
695 if (DECL_P (from
) && !bitmap_bit_p (results_of_malloc
, DECL_UID (from
)))
696 mark_type (to_type
, FULL_ESCAPE
);
698 else if (from_interesting_type
)
699 mark_type (from_type
, FULL_ESCAPE
);
702 /* Register the parameter and return types of function FN. The type
703 ESCAPES if the function is visible outside of the compilation
706 check_function_parameter_and_return_types (tree fn
, bool escapes
)
710 if (TYPE_ARG_TYPES (TREE_TYPE (fn
)))
712 for (arg
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
713 arg
&& TREE_VALUE (arg
) != void_type_node
;
714 arg
= TREE_CHAIN (arg
))
716 tree type
= get_canon_type (TREE_VALUE (arg
), false, false);
718 mark_interesting_type (type
, EXPOSED_PARAMETER
);
723 /* FIXME - According to Geoff Keating, we should never have to
724 do this; the front ends should always process the arg list
725 from the TYPE_ARG_LIST. However, Geoff is wrong, this code
726 does seem to be live. */
728 for (arg
= DECL_ARGUMENTS (fn
); arg
; arg
= TREE_CHAIN (arg
))
730 tree type
= get_canon_type (TREE_TYPE (arg
), false, false);
732 mark_interesting_type (type
, EXPOSED_PARAMETER
);
737 tree type
= get_canon_type (TREE_TYPE (TREE_TYPE (fn
)), false, false);
738 mark_interesting_type (type
, EXPOSED_PARAMETER
);
742 /* Return true if the variable T is the right kind of static variable to
743 perform compilation unit scope escape analysis. */
746 has_proper_scope_for_analysis (tree t
)
748 /* If the variable has the "used" attribute, treat it as if it had a
749 been touched by the devil. */
750 tree type
= get_canon_type (TREE_TYPE (t
), false, false);
753 if (lookup_attribute ("used", DECL_ATTRIBUTES (t
)))
755 mark_interesting_type (type
, FULL_ESCAPE
);
759 /* Do not want to do anything with volatile except mark any
760 function that uses one to be not const or pure. */
761 if (TREE_THIS_VOLATILE (t
))
764 /* Do not care about a local automatic that is not static. */
765 if (!TREE_STATIC (t
) && !DECL_EXTERNAL (t
))
768 if (DECL_EXTERNAL (t
) || TREE_PUBLIC (t
))
770 /* If the front end set the variable to be READONLY and
771 constant, we can allow this variable in pure or const
772 functions but the scope is too large for our analysis to set
773 these bits ourselves. */
775 if (TREE_READONLY (t
)
777 && is_gimple_min_invariant (DECL_INITIAL (t
)))
778 ; /* Read of a constant, do not change the function state. */
781 /* The type escapes for all public and externs. */
782 mark_interesting_type (type
, FULL_ESCAPE
);
787 /* If T is a VAR_DECL for a static that we are interested in, add the
788 uid to the bitmap. */
791 check_operand (tree t
)
795 /* This is an assignment from a function, register the types as
797 if (TREE_CODE (t
) == FUNCTION_DECL
)
798 check_function_parameter_and_return_types (t
, true);
800 else if (TREE_CODE (t
) == VAR_DECL
)
801 has_proper_scope_for_analysis (t
);
804 /* Examine tree T for references. */
809 if ((TREE_CODE (t
) == EXC_PTR_EXPR
) || (TREE_CODE (t
) == FILTER_EXPR
))
812 while (TREE_CODE (t
) == REALPART_EXPR
813 || TREE_CODE (t
) == IMAGPART_EXPR
814 || handled_component_p (t
))
816 if (TREE_CODE (t
) == ARRAY_REF
)
817 check_operand (TREE_OPERAND (t
, 1));
818 t
= TREE_OPERAND (t
, 0);
821 if (INDIRECT_REF_P (t
))
822 /* || TREE_CODE (t) == MEM_REF) */
823 check_tree (TREE_OPERAND (t
, 0));
825 if (SSA_VAR_P (t
) || (TREE_CODE (t
) == FUNCTION_DECL
))
829 /* Create an address_of edge FROM_TYPE.TO_TYPE. */
831 mark_interesting_addressof (tree to_type
, tree from_type
)
836 splay_tree_node result
;
838 from_type
= get_canon_type (from_type
, false, false);
839 to_type
= get_canon_type (to_type
, false, false);
841 if (!from_type
|| !to_type
)
844 from_uid
= TYPE_UID (from_type
);
845 to_uid
= TYPE_UID (to_type
);
847 gcc_assert (ipa_type_escape_star_count_of_interesting_type (from_type
) == 0);
849 /* Process the Y into X map pointer. */
850 result
= splay_tree_lookup (uid_to_addressof_down_map
,
851 (splay_tree_key
) from_uid
);
854 type_map
= (bitmap
) result
->value
;
857 type_map
= BITMAP_ALLOC (&ipa_obstack
);
858 splay_tree_insert (uid_to_addressof_down_map
,
860 (splay_tree_value
)type_map
);
862 bitmap_set_bit (type_map
, TYPE_UID (to_type
));
864 /* Process the X into Y reverse map pointer. */
866 splay_tree_lookup (uid_to_addressof_up_map
, (splay_tree_key
) to_uid
);
869 type_map
= (bitmap
) result
->value
;
872 type_map
= BITMAP_ALLOC (&ipa_obstack
);
873 splay_tree_insert (uid_to_addressof_up_map
,
875 (splay_tree_value
)type_map
);
877 bitmap_set_bit (type_map
, TYPE_UID (to_type
));
880 /* Scan tree T to see if there are any addresses taken in within T. */
883 look_for_address_of (tree t
)
885 if (TREE_CODE (t
) == ADDR_EXPR
)
887 tree x
= get_base_var (t
);
888 tree cref
= TREE_OPERAND (t
, 0);
890 /* If we have an expression of the form "&a.b.c.d", mark a.b,
891 b.c and c.d. as having its address taken. */
892 tree fielddecl
= NULL_TREE
;
895 if (TREE_CODE (cref
) == COMPONENT_REF
)
897 fielddecl
= TREE_OPERAND (cref
, 1);
898 mark_interesting_addressof (TREE_TYPE (fielddecl
),
899 DECL_FIELD_CONTEXT (fielddecl
));
901 else if (TREE_CODE (cref
) == ARRAY_REF
)
902 get_canon_type (TREE_TYPE (cref
), false, false);
904 cref
= TREE_OPERAND (cref
, 0);
907 if (TREE_CODE (x
) == VAR_DECL
)
908 has_proper_scope_for_analysis (x
);
913 /* Scan tree T to see if there are any casts within it.
914 LHS Is the LHS of the expression involving the cast. */
917 look_for_casts (tree lhs
__attribute__((unused
)), tree t
)
919 if (is_gimple_cast (t
) || TREE_CODE (t
) == VIEW_CONVERT_EXPR
)
921 tree castfromvar
= TREE_OPERAND (t
, 0);
922 check_cast (TREE_TYPE (t
), castfromvar
);
924 else if (TREE_CODE (t
) == COMPONENT_REF
925 || TREE_CODE (t
) == INDIRECT_REF
926 || TREE_CODE (t
) == BIT_FIELD_REF
)
928 tree base
= get_base_address (t
);
931 t
= TREE_OPERAND (t
, 0);
932 if (TREE_CODE (t
) == VIEW_CONVERT_EXPR
)
934 /* This may be some part of a component ref.
935 IE it may be a.b.VIEW_CONVERT_EXPR<weird_type>(c).d, AFAIK.
936 castfromref will give you a.b.c, not a. */
937 tree castfromref
= TREE_OPERAND (t
, 0);
938 check_cast (TREE_TYPE (t
), castfromref
);
940 else if (TREE_CODE (t
) == COMPONENT_REF
)
941 get_canon_type (TREE_TYPE (TREE_OPERAND (t
, 1)), false, false);
946 /* Check to see if T is a read or address of operation on a static var
947 we are interested in analyzing. */
950 check_rhs_var (tree t
)
952 look_for_address_of (t
);
956 /* Check to see if T is an assignment to a static var we are
957 interested in analyzing. */
960 check_lhs_var (tree t
)
965 /* This is a scaled down version of get_asm_expr_operands from
966 tree_ssa_operands.c. The version there runs much later and assumes
967 that aliasing information is already available. Here we are just
968 trying to find if the set of inputs and outputs contain references
969 or address of operations to local. FN is the function being
970 analyzed and STMT is the actual asm statement. */
973 get_asm_expr_operands (tree stmt
)
975 int noutputs
= list_length (ASM_OUTPUTS (stmt
));
976 const char **oconstraints
977 = (const char **) alloca ((noutputs
) * sizeof (const char *));
980 const char *constraint
;
981 bool allows_mem
, allows_reg
, is_inout
;
983 for (i
=0, link
= ASM_OUTPUTS (stmt
); link
; ++i
, link
= TREE_CHAIN (link
))
985 oconstraints
[i
] = constraint
986 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
987 parse_output_constraint (&constraint
, i
, 0, 0,
988 &allows_mem
, &allows_reg
, &is_inout
);
990 check_lhs_var (TREE_VALUE (link
));
993 for (link
= ASM_INPUTS (stmt
); link
; link
= TREE_CHAIN (link
))
996 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
997 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0,
998 oconstraints
, &allows_mem
, &allows_reg
);
1000 check_rhs_var (TREE_VALUE (link
));
1003 /* There is no code here to check for asm memory clobbers. The
1004 casual maintainer might think that such code would be necessary,
1005 but that appears to be wrong. In other parts of the compiler,
1006 the asm memory clobbers are assumed to only clobber variables
1007 that are addressable. All types with addressable instances are
1008 assumed to already escape. So, we are protected here. */
1011 /* Check the parameters of a function call to CALL_EXPR to mark the
1012 types that pass across the function boundary. Also check to see if
1013 this is either an indirect call, a call outside the compilation
1017 check_call (tree call_expr
)
1019 int flags
= call_expr_flags(call_expr
);
1020 tree operand_list
= TREE_OPERAND (call_expr
, 1);
1022 tree callee_t
= get_callee_fndecl (call_expr
);
1024 struct cgraph_node
* callee
;
1025 enum availability avail
= AVAIL_NOT_AVAILABLE
;
1027 for (operand
= operand_list
;
1028 operand
!= NULL_TREE
;
1029 operand
= TREE_CHAIN (operand
))
1031 tree argument
= TREE_VALUE (operand
);
1032 check_rhs_var (argument
);
1038 tree last_arg_type
= NULL
;
1039 callee
= cgraph_node(callee_t
);
1040 avail
= cgraph_function_body_availability (callee
);
1042 /* Check that there are no implicit casts in the passing of
1044 if (TYPE_ARG_TYPES (TREE_TYPE (callee_t
)))
1046 operand
= operand_list
;
1047 for (arg_type
= TYPE_ARG_TYPES (TREE_TYPE (callee_t
));
1048 arg_type
&& TREE_VALUE (arg_type
) != void_type_node
;
1049 arg_type
= TREE_CHAIN (arg_type
))
1053 argument
= TREE_VALUE (operand
);
1054 last_arg_type
= TREE_VALUE(arg_type
);
1055 check_cast (last_arg_type
, argument
);
1056 operand
= TREE_CHAIN (operand
);
1059 /* The code reaches here for some unfortunate
1060 builtin functions that do not have a list of
1067 /* FIXME - According to Geoff Keating, we should never
1068 have to do this; the front ends should always process
1069 the arg list from the TYPE_ARG_LIST. */
1070 operand
= operand_list
;
1071 for (arg_type
= DECL_ARGUMENTS (callee_t
);
1073 arg_type
= TREE_CHAIN (arg_type
))
1077 argument
= TREE_VALUE (operand
);
1078 last_arg_type
= TREE_TYPE(arg_type
);
1079 check_cast (last_arg_type
, argument
);
1080 operand
= TREE_CHAIN (operand
);
1083 /* The code reaches here for some unfortunate
1084 builtin functions that do not have a list of
1090 /* In the case where we have a var_args function, we need to
1091 check the remaining parameters against the last argument. */
1092 arg_type
= last_arg_type
;
1094 operand
!= NULL_TREE
;
1095 operand
= TREE_CHAIN (operand
))
1097 argument
= TREE_VALUE (operand
);
1099 check_cast (arg_type
, argument
);
1102 /* The code reaches here for some unfortunate
1103 builtin functions that do not have a list of
1104 argument types. Most of these functions have
1105 been marked as having their parameters not
1106 escape, but for the rest, the type is doomed. */
1107 tree type
= get_canon_type (TREE_TYPE (argument
), false, false);
1108 mark_interesting_type (type
, FULL_ESCAPE
);
1113 /* The callee is either unknown (indirect call) or there is just no
1114 scannable code for it (external call) . We look to see if there
1115 are any bits available for the callee (such as by declaration or
1116 because it is builtin) and process solely on the basis of those
1119 if (avail
== AVAIL_NOT_AVAILABLE
|| avail
== AVAIL_OVERWRITABLE
)
1121 /* If this is a direct call to an external function, mark all of
1122 the parameter and return types. */
1123 for (operand
= operand_list
;
1124 operand
!= NULL_TREE
;
1125 operand
= TREE_CHAIN (operand
))
1128 get_canon_type (TREE_TYPE (TREE_VALUE (operand
)), false, false);
1129 mark_interesting_type (type
, EXPOSED_PARAMETER
);
1135 get_canon_type (TREE_TYPE (TREE_TYPE (callee_t
)), false, false);
1136 mark_interesting_type (type
, EXPOSED_PARAMETER
);
1139 return (flags
& ECF_MALLOC
);
1142 /* CODE is the operation on OP0 and OP1. OP0 is the operand that we
1143 *know* is a pointer type. OP1 may be a pointer type. */
1145 okay_pointer_operation (enum tree_code code
, tree op0
, tree op1
)
1147 tree op0type
= TYPE_MAIN_VARIANT (TREE_TYPE (op0
));
1148 tree op1type
= TYPE_MAIN_VARIANT (TREE_TYPE (op1
));
1149 if (POINTER_TYPE_P (op1type
))
1156 /* TODO: Handle multiples of op0 size as well */
1157 if (operand_equal_p (size_in_bytes (op0type
), op1
, 0))
1167 /* TP is the part of the tree currently under the microscope.
1168 WALK_SUBTREES is part of the walk_tree api but is unused here.
1169 DATA is cgraph_node of the function being walked. */
1171 /* FIXME: When this is converted to run over SSA form, this code
1172 should be converted to use the operand scanner. */
1175 scan_for_refs (tree
*tp
, int *walk_subtrees
, void *data
)
1177 struct cgraph_node
*fn
= data
;
1180 switch (TREE_CODE (t
))
1183 if (DECL_INITIAL (t
))
1184 walk_tree (&DECL_INITIAL (t
), scan_for_refs
, fn
, visited_nodes
);
1190 /* First look on the lhs and see what variable is stored to */
1191 tree lhs
= TREE_OPERAND (t
, 0);
1192 tree rhs
= TREE_OPERAND (t
, 1);
1194 check_lhs_var (lhs
);
1195 check_cast (TREE_TYPE (lhs
), rhs
);
1197 /* For the purposes of figuring out what the cast affects */
1199 /* Next check the operands on the rhs to see if they are ok. */
1200 switch (TREE_CODE_CLASS (TREE_CODE (rhs
)))
1204 tree op0
= TREE_OPERAND (rhs
, 0);
1205 tree type0
= get_canon_type (TREE_TYPE (op0
), false, false);
1206 tree op1
= TREE_OPERAND (rhs
, 1);
1207 tree type1
= get_canon_type (TREE_TYPE (op1
), false, false);
1209 /* If this is pointer arithmetic of any bad sort, then
1210 we need to mark the types as bad. For binary
1211 operations, no binary operator we currently support
1212 is always "safe" in regard to what it would do to
1213 pointers for purposes of determining which types
1214 escape, except operations of the size of the type.
1215 It is possible that min and max under the right set
1216 of circumstances and if the moon is in the correct
1217 place could be safe, but it is hard to see how this
1218 is worth the effort. */
1220 if (type0
&& POINTER_TYPE_P (type0
)
1221 && !okay_pointer_operation (TREE_CODE (rhs
), op0
, op1
))
1222 mark_interesting_type (type0
, FULL_ESCAPE
);
1223 if (type1
&& POINTER_TYPE_P (type1
)
1224 && !okay_pointer_operation (TREE_CODE (rhs
), op1
, op0
))
1225 mark_interesting_type (type1
, FULL_ESCAPE
);
1227 look_for_casts (lhs
, op0
);
1228 look_for_casts (lhs
, op1
);
1229 check_rhs_var (op0
);
1230 check_rhs_var (op1
);
1235 tree op0
= TREE_OPERAND (rhs
, 0);
1236 tree type0
= get_canon_type (TREE_TYPE (op0
), false, false);
1237 /* For unary operations, if the operation is NEGATE or
1238 ABS on a pointer, this is also considered pointer
1239 arithmetic and thus, bad for business. */
1240 if (type0
&& (TREE_CODE (op0
) == NEGATE_EXPR
1241 || TREE_CODE (op0
) == ABS_EXPR
)
1242 && POINTER_TYPE_P (type0
))
1244 mark_interesting_type (type0
, FULL_ESCAPE
);
1246 check_rhs_var (op0
);
1247 look_for_casts (lhs
, op0
);
1248 look_for_casts (lhs
, rhs
);
1253 look_for_casts (lhs
, rhs
);
1254 check_rhs_var (rhs
);
1256 case tcc_declaration
:
1257 check_rhs_var (rhs
);
1259 case tcc_expression
:
1260 switch (TREE_CODE (rhs
))
1263 look_for_casts (lhs
, TREE_OPERAND (rhs
, 0));
1264 check_rhs_var (rhs
);
1267 /* If this is a call to malloc, squirrel away the
1268 result so we do mark the resulting cast as being
1270 if (check_call (rhs
))
1271 bitmap_set_bit (results_of_malloc
, DECL_UID (lhs
));
1285 /* This case is here to find addresses on rhs of constructors in
1286 decl_initial of static variables. */
1297 get_asm_expr_operands (t
);
1308 /* The init routine for analyzing global static variable usage. See
1309 comments at top for description. */
1313 bitmap_obstack_initialize (&ipa_obstack
);
1314 global_types_exposed_parameter
= BITMAP_ALLOC (&ipa_obstack
);
1315 global_types_full_escape
= BITMAP_ALLOC (&ipa_obstack
);
1316 global_types_seen
= BITMAP_ALLOC (&ipa_obstack
);
1317 results_of_malloc
= BITMAP_ALLOC (&ipa_obstack
);
1319 uid_to_canon_type
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1320 all_canon_types
= splay_tree_new (compare_type_brand
, 0, 0);
1321 type_to_canon_type
= splay_tree_new (splay_tree_compare_pointers
, 0, 0);
1322 uid_to_subtype_map
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1323 uid_to_addressof_down_map
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1324 uid_to_addressof_up_map
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1326 /* There are some shared nodes, in particular the initializers on
1327 static declarations. We do not need to scan them more than once
1328 since all we would be interested in are the addressof
1330 visited_nodes
= pointer_set_create ();
1334 /* Check out the rhs of a static or global initialization VNODE to see
1335 if any of them contain addressof operations. Note that some of
1336 these variables may not even be referenced in the code in this
1337 compilation unit but their right hand sides may contain references
1338 to variables defined within this unit. */
1341 analyze_variable (struct cgraph_varpool_node
*vnode
)
1343 tree global
= vnode
->decl
;
1344 tree type
= get_canon_type (TREE_TYPE (global
), false, false);
1346 /* If this variable has exposure beyond the compilation unit, add
1347 its type to the global types. */
1349 if (vnode
->externally_visible
)
1350 mark_interesting_type (type
, FULL_ESCAPE
);
1352 gcc_assert (TREE_CODE (global
) == VAR_DECL
);
1354 if (DECL_INITIAL (global
))
1355 walk_tree (&DECL_INITIAL (global
), scan_for_refs
, NULL
, visited_nodes
);
1358 /* This is the main routine for finding the reference patterns for
1359 global variables within a function FN. */
1362 analyze_function (struct cgraph_node
*fn
)
1364 tree decl
= fn
->decl
;
1365 check_function_parameter_and_return_types (decl
,
1366 fn
->local
.externally_visible
);
1368 fprintf (dump_file
, "\n local analysis of %s", cgraph_node_name (fn
));
1371 struct function
*this_cfun
= DECL_STRUCT_FUNCTION (decl
);
1372 basic_block this_block
;
1374 FOR_EACH_BB_FN (this_block
, this_cfun
)
1376 block_stmt_iterator bsi
;
1377 for (bsi
= bsi_start (this_block
); !bsi_end_p (bsi
); bsi_next (&bsi
))
1378 walk_tree (bsi_stmt_ptr (bsi
), scan_for_refs
,
1383 /* There may be const decls with interesting right hand sides. */
1384 if (DECL_STRUCT_FUNCTION (decl
))
1387 for (step
= DECL_STRUCT_FUNCTION (decl
)->unexpanded_var_list
;
1389 step
= TREE_CHAIN (step
))
1391 tree var
= TREE_VALUE (step
);
1392 if (TREE_CODE (var
) == VAR_DECL
1393 && DECL_INITIAL (var
)
1394 && !TREE_STATIC (var
))
1395 walk_tree (&DECL_INITIAL (var
), scan_for_refs
,
1397 get_canon_type (TREE_TYPE (var
), false, false);
1404 /* Convert a type_UID into a type. */
1406 type_for_uid (int uid
)
1408 splay_tree_node result
=
1409 splay_tree_lookup (uid_to_canon_type
, (splay_tree_key
) uid
);
1412 return (tree
) result
->value
;
1416 /* Return the a bitmap with the subtypes of the type for UID. If it
1417 does not exist, return either NULL or a new bitmap depending on the
1421 subtype_map_for_uid (int uid
, bool create
)
1423 splay_tree_node result
= splay_tree_lookup (uid_to_subtype_map
,
1424 (splay_tree_key
) uid
);
1427 return (bitmap
) result
->value
;
1430 bitmap subtype_map
= BITMAP_ALLOC (&ipa_obstack
);
1431 splay_tree_insert (uid_to_subtype_map
,
1433 (splay_tree_value
)subtype_map
);
1439 /* Mark all of the supertypes and field types of TYPE as being seen.
1440 Also accumulate the subtypes for each type so that
1441 close_types_full_escape can mark a subtype as escaping if the
1442 supertype escapes. */
1445 close_type_seen (tree type
)
1449 tree binfo
, base_binfo
;
1451 /* See thru all pointer tos and array ofs. */
1452 type
= get_canon_type (type
, true, true);
1456 uid
= TYPE_UID (type
);
1458 if (bitmap_bit_p (been_there_done_that
, uid
))
1460 bitmap_set_bit (been_there_done_that
, uid
);
1462 /* If we are doing a language with a type hierarchy, mark all of
1463 the superclasses. */
1464 if (TYPE_BINFO (type
))
1465 for (binfo
= TYPE_BINFO (type
), i
= 0;
1466 BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1468 tree binfo_type
= BINFO_TYPE (base_binfo
);
1469 bitmap subtype_map
= subtype_map_for_uid
1470 (TYPE_UID (TYPE_MAIN_VARIANT (binfo_type
)), true);
1471 bitmap_set_bit (subtype_map
, uid
);
1472 close_type_seen (get_canon_type (binfo_type
, true, true));
1475 /* If the field is a struct or union type, mark all of the
1477 for (field
= TYPE_FIELDS (type
);
1479 field
= TREE_CHAIN (field
))
1482 if (TREE_CODE (field
) != FIELD_DECL
)
1485 field_type
= TREE_TYPE (field
);
1486 if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type
) >= 0)
1487 close_type_seen (get_canon_type (field_type
, true, true));
1491 /* Take a TYPE that has been passed by value to an external function
1492 and mark all of the fields that have pointer types as escaping. For
1493 any of the non pointer types that are structures or unions,
1494 recurse. TYPE is never a pointer type. */
1497 close_type_exposed_parameter (tree type
)
1502 type
= get_canon_type (type
, false, false);
1505 uid
= TYPE_UID (type
);
1506 gcc_assert (!POINTER_TYPE_P (type
));
1508 if (bitmap_bit_p (been_there_done_that
, uid
))
1510 bitmap_set_bit (been_there_done_that
, uid
);
1512 /* If the field is a struct or union type, mark all of the
1514 for (field
= TYPE_FIELDS (type
);
1516 field
= TREE_CHAIN (field
))
1520 if (TREE_CODE (field
) != FIELD_DECL
)
1523 field_type
= get_canon_type (TREE_TYPE (field
), false, false);
1524 mark_interesting_type (field_type
, EXPOSED_PARAMETER
);
1526 /* Only recurse for non pointer types of structures and unions. */
1527 if (ipa_type_escape_star_count_of_interesting_type (field_type
) == 0)
1528 close_type_exposed_parameter (field_type
);
1532 /* The next function handles the case where a type fully escapes.
1533 This means that not only does the type itself escape,
1535 a) the type of every field recursively escapes
1536 b) the type of every subtype escapes as well as the super as well
1537 as all of the pointer to types for each field.
1539 Note that pointer to types are not marked as escaping. If the
1540 pointed to type escapes, the pointer to type also escapes.
1542 Take a TYPE that has had the address taken for an instance of it
1543 and mark all of the types for its fields as having their addresses
1547 close_type_full_escape (tree type
)
1552 tree binfo
, base_binfo
;
1555 splay_tree_node address_result
;
1557 /* Strip off any pointer or array types. */
1558 type
= get_canon_type (type
, true, true);
1561 uid
= TYPE_UID (type
);
1563 if (bitmap_bit_p (been_there_done_that
, uid
))
1565 bitmap_set_bit (been_there_done_that
, uid
);
1567 subtype_map
= subtype_map_for_uid (uid
, false);
1569 /* If we are doing a language with a type hierarchy, mark all of
1570 the superclasses. */
1571 if (TYPE_BINFO (type
))
1572 for (binfo
= TYPE_BINFO (type
), i
= 0;
1573 BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1575 tree binfotype
= BINFO_TYPE (base_binfo
);
1576 binfotype
= mark_type (binfotype
, FULL_ESCAPE
);
1577 close_type_full_escape (binfotype
);
1580 /* Mark as escaped any types that have been down casted to
1583 EXECUTE_IF_SET_IN_BITMAP (subtype_map
, 0, i
, bi
)
1585 tree subtype
= type_for_uid (i
);
1586 subtype
= mark_type (subtype
, FULL_ESCAPE
);
1587 close_type_full_escape (subtype
);
1590 /* If the field is a struct or union type, mark all of the
1592 for (field
= TYPE_FIELDS (type
);
1594 field
= TREE_CHAIN (field
))
1597 if (TREE_CODE (field
) != FIELD_DECL
)
1600 field_type
= TREE_TYPE (field
);
1601 if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type
) >= 0)
1603 field_type
= mark_type (field_type
, FULL_ESCAPE
);
1604 close_type_full_escape (field_type
);
1608 /* For all of the types A that contain this type B and were part of
1609 an expression like "&...A.B...", mark the A's as escaping. */
1610 address_result
= splay_tree_lookup (uid_to_addressof_up_map
,
1611 (splay_tree_key
) uid
);
1614 bitmap containing_classes
= (bitmap
) address_result
->value
;
1615 EXECUTE_IF_SET_IN_BITMAP (containing_classes
, 0, i
, bi
)
1617 close_type_full_escape (type_for_uid (i
));
1622 /* Transitively close the addressof bitmap for the type with UID.
1623 This means that if we had a.b and b.c, a would have both b and c in
1627 close_addressof_down (int uid
)
1630 splay_tree_node result
=
1631 splay_tree_lookup (uid_to_addressof_down_map
, (splay_tree_key
) uid
);
1637 map
= (bitmap
) result
->value
;
1641 if (bitmap_bit_p (been_there_done_that
, uid
))
1643 bitmap_set_bit (been_there_done_that
, uid
);
1645 /* If the type escapes, get rid of the addressof map, it will not be
1647 if (bitmap_bit_p (global_types_full_escape
, uid
))
1650 splay_tree_remove (uid_to_addressof_down_map
, (splay_tree_key
) uid
);
1654 /* The new_map will have all of the bits for the enclosed fields and
1655 will have the unique id version of the old map. */
1656 new_map
= BITMAP_ALLOC (&ipa_obstack
);
1658 EXECUTE_IF_SET_IN_BITMAP (map
, 0, i
, bi
)
1660 bitmap submap
= close_addressof_down (i
);
1661 bitmap_set_bit (new_map
, i
);
1663 bitmap_ior_into (new_map
, submap
);
1665 result
->value
= (splay_tree_value
) new_map
;
1672 /* The main entry point for type escape analysis. */
1675 type_escape_execute (void)
1677 struct cgraph_node
*node
;
1678 struct cgraph_varpool_node
*vnode
;
1681 splay_tree_node result
;
1685 /* Process all of the variables first. */
1686 for (vnode
= cgraph_varpool_nodes_queue
; vnode
; vnode
= vnode
->next_needed
)
1687 analyze_variable (vnode
);
1689 /* Process all of the functions. next
1691 We do not want to process any of the clones so we check that this
1692 is a master clone. However, we do need to process any
1693 AVAIL_OVERWRITABLE functions (these are never clones) because
1694 they may cause a type variable to escape.
1696 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1698 && (cgraph_is_master_clone (node
)
1699 || (cgraph_function_body_availability (node
) == AVAIL_OVERWRITABLE
)))
1700 analyze_function (node
);
1703 pointer_set_destroy (visited_nodes
);
1704 visited_nodes
= NULL
;
1706 /* Do all of the closures to discover which types escape the
1707 compilation unit. */
1709 been_there_done_that
= BITMAP_ALLOC (&ipa_obstack
);
1710 bitmap_tmp
= BITMAP_ALLOC (&ipa_obstack
);
1712 /* Examine the types that we have directly seen in scanning the code
1713 and add to that any contained types or superclasses. */
1715 bitmap_copy (bitmap_tmp
, global_types_seen
);
1716 EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp
, 0, i
, bi
)
1718 tree type
= type_for_uid (i
);
1719 /* Only look at records and unions and pointer tos. */
1720 if (ipa_type_escape_star_count_of_interesting_or_array_type (type
) >= 0)
1721 close_type_seen (type
);
1723 bitmap_clear (been_there_done_that
);
1725 /* Examine all of the types passed by value and mark any enclosed
1726 pointer types as escaping. */
1727 bitmap_copy (bitmap_tmp
, global_types_exposed_parameter
);
1728 EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp
, 0, i
, bi
)
1730 close_type_exposed_parameter (type_for_uid (i
));
1732 bitmap_clear (been_there_done_that
);
1734 /* Close the types for escape. If something escapes, then any
1735 enclosed types escape as well as any subtypes. */
1736 bitmap_copy (bitmap_tmp
, global_types_full_escape
);
1737 EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp
, 0, i
, bi
)
1739 close_type_full_escape (type_for_uid (i
));
1741 bitmap_clear (been_there_done_that
);
1743 /* Before this pass, the uid_to_addressof_down_map for type X
1744 contained an entry for Y if there had been an operation of the
1745 form &X.Y. This step adds all of the fields contained within Y
1746 (recursively) to X's map. */
1748 result
= splay_tree_min (uid_to_addressof_down_map
);
1751 int uid
= result
->key
;
1752 /* Close the addressof map, i.e. copy all of the transitive
1753 substructures up to this level. */
1754 close_addressof_down (uid
);
1755 result
= splay_tree_successor (uid_to_addressof_down_map
, uid
);
1758 /* Do not need the array types and pointer types in the persistent
1760 result
= splay_tree_min (all_canon_types
);
1763 tree type
= (tree
) result
->value
;
1764 tree key
= (tree
) result
->key
;
1765 if (POINTER_TYPE_P (type
)
1766 || TREE_CODE (type
) == ARRAY_TYPE
)
1768 splay_tree_remove (all_canon_types
, (splay_tree_key
) result
->key
);
1769 splay_tree_remove (type_to_canon_type
, (splay_tree_key
) type
);
1770 splay_tree_remove (uid_to_canon_type
, (splay_tree_key
) TYPE_UID (type
));
1771 bitmap_clear_bit (global_types_seen
, TYPE_UID (type
));
1773 result
= splay_tree_successor (all_canon_types
, (splay_tree_key
) key
);
1777 /* FILE * tmp = dump_file; */
1778 /* dump_file = stderr; */
1781 EXECUTE_IF_SET_IN_BITMAP (global_types_seen
, 0, i
, bi
)
1783 /* The pointer types are in the global_types_full_escape
1784 bitmap but not in the backwards map. They also contain
1785 no useful information since they are not marked. */
1786 tree type
= type_for_uid (i
);
1787 fprintf(dump_file
, "type %d ", i
);
1788 print_generic_expr (dump_file
, type
, 0);
1789 if (bitmap_bit_p (global_types_full_escape
, i
))
1790 fprintf(dump_file
, " escaped\n");
1792 fprintf(dump_file
, " contained\n");
1795 /* dump_file = tmp; */
1798 /* Get rid of uid_to_addressof_up_map and its bitmaps. */
1799 result
= splay_tree_min (uid_to_addressof_up_map
);
1802 int uid
= (int)result
->key
;
1803 bitmap bm
= (bitmap
)result
->value
;
1806 splay_tree_remove (uid_to_addressof_up_map
, (splay_tree_key
) uid
);
1807 result
= splay_tree_successor (uid_to_addressof_up_map
, uid
);
1810 /* Get rid of the subtype map. */
1811 result
= splay_tree_min (uid_to_subtype_map
);
1814 bitmap b
= (bitmap
)result
->value
;
1816 splay_tree_remove (uid_to_subtype_map
, result
->key
);
1817 result
= splay_tree_min (uid_to_subtype_map
);
1819 splay_tree_delete (uid_to_subtype_map
);
1820 uid_to_subtype_map
= NULL
;
1822 BITMAP_FREE (global_types_exposed_parameter
);
1823 BITMAP_FREE (been_there_done_that
);
1824 BITMAP_FREE (bitmap_tmp
);
1825 BITMAP_FREE (results_of_malloc
);
1829 gate_type_escape_vars (void)
1831 return (flag_unit_at_a_time
!= 0 && flag_ipa_type_escape
1832 /* Don't bother doing anything if the program has errors. */
1833 && !(errorcount
|| sorrycount
));
1836 struct tree_opt_pass pass_ipa_type_escape
=
1838 "type-escape-var", /* name */
1839 gate_type_escape_vars
, /* gate */
1840 type_escape_execute
, /* execute */
1843 0, /* static_pass_number */
1844 TV_IPA_TYPE_ESCAPE
, /* tv_id */
1845 0, /* properties_required */
1846 0, /* properties_provided */
1847 0, /* properties_destroyed */
1848 0, /* todo_flags_start */
1849 0, /* todo_flags_finish */