1 /* Type based alias analysis.
2 Copyright (C) 2004, 2005, 2006 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
= XNEW (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
))
273 case QUAL_UNION_TYPE
:
286 /* Get the canon type of TYPE. If SEE_THRU_PTRS is true, remove all
287 the POINTER_TOs and if SEE_THRU_ARRAYS is true, remove all of the
288 ARRAY_OFs and POINTER_TOs. */
291 get_canon_type (tree type
, bool see_thru_ptrs
, bool see_thru_arrays
)
293 splay_tree_node result
;
294 /* Strip the *'s off. */
295 if (!type
|| !type_to_consider (type
))
298 type
= TYPE_MAIN_VARIANT (type
);
300 while (POINTER_TYPE_P (type
) || TREE_CODE (type
) == ARRAY_TYPE
)
301 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
303 else if (see_thru_ptrs
)
304 while (POINTER_TYPE_P (type
))
305 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
307 result
= splay_tree_lookup(type_to_canon_type
, (splay_tree_key
) type
);
310 return discover_unique_type (type
);
311 else return (tree
) result
->value
;
314 /* Same as GET_CANON_TYPE, except return the TYPE_ID rather than the
318 get_canon_type_uid (tree type
, bool see_thru_ptrs
, bool see_thru_arrays
)
320 type
= get_canon_type (type
, see_thru_ptrs
, see_thru_arrays
);
322 return TYPE_UID(type
);
326 /* Return 0 if TYPE is a record or union type. Return a positive
327 number if TYPE is a pointer to a record or union. The number is
328 the number of pointer types stripped to get to the record or union
329 type. Return -1 if TYPE is none of the above. */
332 ipa_type_escape_star_count_of_interesting_type (tree type
)
335 /* Strip the *'s off. */
338 type
= TYPE_MAIN_VARIANT (type
);
339 while (POINTER_TYPE_P (type
))
341 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
345 /* We are interested in records, and unions only. */
346 if (TREE_CODE (type
) == RECORD_TYPE
347 || TREE_CODE (type
) == QUAL_UNION_TYPE
348 || TREE_CODE (type
) == UNION_TYPE
)
355 /* Return 0 if TYPE is a record or union type. Return a positive
356 number if TYPE is a pointer to a record or union. The number is
357 the number of pointer types stripped to get to the record or union
358 type. Return -1 if TYPE is none of the above. */
361 ipa_type_escape_star_count_of_interesting_or_array_type (tree type
)
364 /* Strip the *'s off. */
367 type
= TYPE_MAIN_VARIANT (type
);
368 while (POINTER_TYPE_P (type
) || TREE_CODE (type
) == ARRAY_TYPE
)
370 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
374 /* We are interested in records, and unions only. */
375 if (TREE_CODE (type
) == RECORD_TYPE
376 || TREE_CODE (type
) == QUAL_UNION_TYPE
377 || TREE_CODE (type
) == UNION_TYPE
)
384 /* Return true if the record, or union TYPE passed in escapes this
385 compilation unit. Note that all of the pointer-to's are removed
386 before testing since these may not be correct. */
389 ipa_type_escape_type_contained_p (tree type
)
393 return !bitmap_bit_p (global_types_full_escape
,
394 get_canon_type_uid (type
, true, false));
397 /* Return true if a modification to a field of type FIELD_TYPE cannot
398 clobber a record of RECORD_TYPE. */
401 ipa_type_escape_field_does_not_clobber_p (tree record_type
, tree field_type
)
403 splay_tree_node result
;
409 /* Strip off all of the pointer tos on the record type. Strip the
410 same number of pointer tos from the field type. If the field
411 type has fewer, it could not have been aliased. */
412 record_type
= TYPE_MAIN_VARIANT (record_type
);
413 field_type
= TYPE_MAIN_VARIANT (field_type
);
414 while (POINTER_TYPE_P (record_type
))
416 record_type
= TYPE_MAIN_VARIANT (TREE_TYPE (record_type
));
417 if (POINTER_TYPE_P (field_type
))
418 field_type
= TYPE_MAIN_VARIANT (TREE_TYPE (field_type
));
420 /* However, if field_type is a union, this quick test is not
421 correct since one of the variants of the union may be a
422 pointer to type and we cannot see across that here. So we
423 just strip the remaining pointer tos off the record type
424 and fall thru to the more precise code. */
425 if (TREE_CODE (field_type
) == QUAL_UNION_TYPE
426 || TREE_CODE (field_type
) == UNION_TYPE
)
428 while (POINTER_TYPE_P (record_type
))
429 record_type
= TYPE_MAIN_VARIANT (TREE_TYPE (record_type
));
436 record_type
= get_canon_type (record_type
, true, true);
437 /* The record type must be contained. The field type may
439 if (!ipa_type_escape_type_contained_p (record_type
))
442 uid
= TYPE_UID (record_type
);
443 result
= splay_tree_lookup (uid_to_addressof_down_map
, (splay_tree_key
) uid
);
447 bitmap field_type_map
= (bitmap
) result
->value
;
448 uid
= get_canon_type_uid (field_type
, true, true);
449 /* If the bit is there, the address was taken. If not, it
451 return !bitmap_bit_p (field_type_map
, uid
);
454 /* No bitmap means no addresses were taken. */
459 /* Add TYPE to the suspect type set. Return true if the bit needed to
463 mark_type (tree type
, enum escape_t escape_status
)
468 type
= get_canon_type (type
, true, true);
472 switch (escape_status
)
474 case EXPOSED_PARAMETER
:
475 map
= global_types_exposed_parameter
;
478 map
= global_types_full_escape
;
482 uid
= TYPE_UID (type
);
483 if (bitmap_bit_p (map
, uid
))
487 bitmap_set_bit (map
, uid
);
488 if (escape_status
== FULL_ESCAPE
)
490 /* Efficiency hack. When things are bad, do not mess around
491 with this type anymore. */
492 bitmap_set_bit (global_types_exposed_parameter
, uid
);
498 /* Add interesting TYPE to the suspect type set. If the set is
499 EXPOSED_PARAMETER and the TYPE is a pointer type, the set is
500 changed to FULL_ESCAPE. */
503 mark_interesting_type (tree type
, enum escape_t escape_status
)
506 if (ipa_type_escape_star_count_of_interesting_type (type
) >= 0)
508 if ((escape_status
== EXPOSED_PARAMETER
)
509 && POINTER_TYPE_P (type
))
510 /* EXPOSED_PARAMETERs are only structs or unions are passed by
511 value. Anything passed by reference to an external
512 function fully exposes the type. */
513 mark_type (type
, FULL_ESCAPE
);
515 mark_type (type
, escape_status
);
519 /* Return true if PARENT is supertype of CHILD. Both types must be
520 known to be structures or unions. */
523 parent_type_p (tree parent
, tree child
)
526 tree binfo
, base_binfo
;
527 if (TYPE_BINFO (parent
))
528 for (binfo
= TYPE_BINFO (parent
), i
= 0;
529 BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
531 tree binfotype
= BINFO_TYPE (base_binfo
);
532 if (binfotype
== child
)
534 else if (parent_type_p (binfotype
, child
))
537 if (TREE_CODE (parent
) == UNION_TYPE
538 || TREE_CODE (parent
) == QUAL_UNION_TYPE
)
541 /* Search all of the variants in the union to see if one of them
543 for (field
= TYPE_FIELDS (parent
);
545 field
= TREE_CHAIN (field
))
548 if (TREE_CODE (field
) != FIELD_DECL
)
551 field_type
= TREE_TYPE (field
);
552 if (field_type
== child
)
556 /* If we did not find it, recursively ask the variants if one of
557 their children is the child type. */
558 for (field
= TYPE_FIELDS (parent
);
560 field
= TREE_CHAIN (field
))
563 if (TREE_CODE (field
) != FIELD_DECL
)
566 field_type
= TREE_TYPE (field
);
567 if (TREE_CODE (field_type
) == RECORD_TYPE
568 || TREE_CODE (field_type
) == QUAL_UNION_TYPE
569 || TREE_CODE (field_type
) == UNION_TYPE
)
570 if (parent_type_p (field_type
, child
))
575 if (TREE_CODE (parent
) == RECORD_TYPE
)
578 for (field
= TYPE_FIELDS (parent
);
580 field
= TREE_CHAIN (field
))
583 if (TREE_CODE (field
) != FIELD_DECL
)
586 field_type
= TREE_TYPE (field
);
587 if (field_type
== child
)
589 /* You can only cast to the first field so if it does not
591 if (TREE_CODE (field_type
) == RECORD_TYPE
592 || TREE_CODE (field_type
) == QUAL_UNION_TYPE
593 || TREE_CODE (field_type
) == UNION_TYPE
)
595 if (parent_type_p (field_type
, child
))
605 /* Return the number of pointer tos for TYPE and return TYPE with all
606 of these stripped off. */
609 count_stars (tree
* type_ptr
)
611 tree type
= *type_ptr
;
613 type
= TYPE_MAIN_VARIANT (type
);
614 while (POINTER_TYPE_P (type
))
616 type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
631 /* Check the cast FROM_TYPE to TO_TYPE. This function requires that
632 the two types have already passed the
633 ipa_type_escape_star_count_of_interesting_type test. */
635 static enum cast_type
636 check_cast_type (tree to_type
, tree from_type
)
638 int to_stars
= count_stars (&to_type
);
639 int from_stars
= count_stars (&from_type
);
640 if (to_stars
!= from_stars
)
643 if (to_type
== from_type
)
646 if (parent_type_p (to_type
, from_type
)) return CT_UP
;
647 if (parent_type_p (from_type
, to_type
)) return CT_DOWN
;
651 /* Check a cast FROM this variable, TO_TYPE. Mark the escaping types
654 check_cast (tree to_type
, tree from
)
656 tree from_type
= get_canon_type (TREE_TYPE (from
), false, false);
657 bool to_interesting_type
, from_interesting_type
;
659 to_type
= get_canon_type (to_type
, false, false);
660 if (!from_type
|| !to_type
|| from_type
== to_type
)
663 to_interesting_type
=
664 ipa_type_escape_star_count_of_interesting_type (to_type
) >= 0;
665 from_interesting_type
=
666 ipa_type_escape_star_count_of_interesting_type (from_type
) >= 0;
668 if (to_interesting_type
)
669 if (from_interesting_type
)
671 /* Both types are interesting. This can be one of four types
672 of cast: useless, up, down, or sideways. We do not care
673 about up or useless. Sideways casts are always bad and
674 both sides get marked as escaping. Downcasts are not
675 interesting here because if type is marked as escaping, all
676 of its subtypes escape. */
677 switch (check_cast_type (to_type
, from_type
))
685 mark_type (to_type
, FULL_ESCAPE
);
686 mark_type (from_type
, FULL_ESCAPE
);
692 /* If this is a cast from the local that is a result from a
693 call to malloc, do not mark the cast as bad. */
694 if (DECL_P (from
) && !bitmap_bit_p (results_of_malloc
, DECL_UID (from
)))
695 mark_type (to_type
, FULL_ESCAPE
);
697 else if (from_interesting_type
)
698 mark_type (from_type
, FULL_ESCAPE
);
701 /* Register the parameter and return types of function FN. The type
702 ESCAPES if the function is visible outside of the compilation
705 check_function_parameter_and_return_types (tree fn
, bool escapes
)
709 if (TYPE_ARG_TYPES (TREE_TYPE (fn
)))
711 for (arg
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
712 arg
&& TREE_VALUE (arg
) != void_type_node
;
713 arg
= TREE_CHAIN (arg
))
715 tree type
= get_canon_type (TREE_VALUE (arg
), false, false);
717 mark_interesting_type (type
, EXPOSED_PARAMETER
);
722 /* FIXME - According to Geoff Keating, we should never have to
723 do this; the front ends should always process the arg list
724 from the TYPE_ARG_LIST. However, Geoff is wrong, this code
725 does seem to be live. */
727 for (arg
= DECL_ARGUMENTS (fn
); arg
; arg
= TREE_CHAIN (arg
))
729 tree type
= get_canon_type (TREE_TYPE (arg
), false, false);
731 mark_interesting_type (type
, EXPOSED_PARAMETER
);
736 tree type
= get_canon_type (TREE_TYPE (TREE_TYPE (fn
)), false, false);
737 mark_interesting_type (type
, EXPOSED_PARAMETER
);
741 /* Return true if the variable T is the right kind of static variable to
742 perform compilation unit scope escape analysis. */
745 has_proper_scope_for_analysis (tree t
)
747 /* If the variable has the "used" attribute, treat it as if it had a
748 been touched by the devil. */
749 tree type
= get_canon_type (TREE_TYPE (t
), false, false);
752 if (lookup_attribute ("used", DECL_ATTRIBUTES (t
)))
754 mark_interesting_type (type
, FULL_ESCAPE
);
758 /* Do not want to do anything with volatile except mark any
759 function that uses one to be not const or pure. */
760 if (TREE_THIS_VOLATILE (t
))
763 /* Do not care about a local automatic that is not static. */
764 if (!TREE_STATIC (t
) && !DECL_EXTERNAL (t
))
767 if (DECL_EXTERNAL (t
) || TREE_PUBLIC (t
))
769 /* If the front end set the variable to be READONLY and
770 constant, we can allow this variable in pure or const
771 functions but the scope is too large for our analysis to set
772 these bits ourselves. */
774 if (TREE_READONLY (t
)
776 && is_gimple_min_invariant (DECL_INITIAL (t
)))
777 ; /* Read of a constant, do not change the function state. */
780 /* The type escapes for all public and externs. */
781 mark_interesting_type (type
, FULL_ESCAPE
);
786 /* If T is a VAR_DECL for a static that we are interested in, add the
787 uid to the bitmap. */
790 check_operand (tree t
)
794 /* This is an assignment from a function, register the types as
796 if (TREE_CODE (t
) == FUNCTION_DECL
)
797 check_function_parameter_and_return_types (t
, true);
799 else if (TREE_CODE (t
) == VAR_DECL
)
800 has_proper_scope_for_analysis (t
);
803 /* Examine tree T for references. */
808 if ((TREE_CODE (t
) == EXC_PTR_EXPR
) || (TREE_CODE (t
) == FILTER_EXPR
))
811 while (TREE_CODE (t
) == REALPART_EXPR
812 || TREE_CODE (t
) == IMAGPART_EXPR
813 || handled_component_p (t
))
815 if (TREE_CODE (t
) == ARRAY_REF
)
816 check_operand (TREE_OPERAND (t
, 1));
817 t
= TREE_OPERAND (t
, 0);
820 if (INDIRECT_REF_P (t
))
821 /* || TREE_CODE (t) == MEM_REF) */
822 check_tree (TREE_OPERAND (t
, 0));
824 if (SSA_VAR_P (t
) || (TREE_CODE (t
) == FUNCTION_DECL
))
828 /* Create an address_of edge FROM_TYPE.TO_TYPE. */
830 mark_interesting_addressof (tree to_type
, tree from_type
)
835 splay_tree_node result
;
837 from_type
= get_canon_type (from_type
, false, false);
838 to_type
= get_canon_type (to_type
, false, false);
840 if (!from_type
|| !to_type
)
843 from_uid
= TYPE_UID (from_type
);
844 to_uid
= TYPE_UID (to_type
);
846 gcc_assert (ipa_type_escape_star_count_of_interesting_type (from_type
) == 0);
848 /* Process the Y into X map pointer. */
849 result
= splay_tree_lookup (uid_to_addressof_down_map
,
850 (splay_tree_key
) from_uid
);
853 type_map
= (bitmap
) result
->value
;
856 type_map
= BITMAP_ALLOC (&ipa_obstack
);
857 splay_tree_insert (uid_to_addressof_down_map
,
859 (splay_tree_value
)type_map
);
861 bitmap_set_bit (type_map
, TYPE_UID (to_type
));
863 /* Process the X into Y reverse map pointer. */
865 splay_tree_lookup (uid_to_addressof_up_map
, (splay_tree_key
) to_uid
);
868 type_map
= (bitmap
) result
->value
;
871 type_map
= BITMAP_ALLOC (&ipa_obstack
);
872 splay_tree_insert (uid_to_addressof_up_map
,
874 (splay_tree_value
)type_map
);
876 bitmap_set_bit (type_map
, TYPE_UID (to_type
));
879 /* Scan tree T to see if there are any addresses taken in within T. */
882 look_for_address_of (tree t
)
884 if (TREE_CODE (t
) == ADDR_EXPR
)
886 tree x
= get_base_var (t
);
887 tree cref
= TREE_OPERAND (t
, 0);
889 /* If we have an expression of the form "&a.b.c.d", mark a.b,
890 b.c and c.d. as having its address taken. */
891 tree fielddecl
= NULL_TREE
;
894 if (TREE_CODE (cref
) == COMPONENT_REF
)
896 fielddecl
= TREE_OPERAND (cref
, 1);
897 mark_interesting_addressof (TREE_TYPE (fielddecl
),
898 DECL_FIELD_CONTEXT (fielddecl
));
900 else if (TREE_CODE (cref
) == ARRAY_REF
)
901 get_canon_type (TREE_TYPE (cref
), false, false);
903 cref
= TREE_OPERAND (cref
, 0);
906 if (TREE_CODE (x
) == VAR_DECL
)
907 has_proper_scope_for_analysis (x
);
912 /* Scan tree T to see if there are any casts within it.
913 LHS Is the LHS of the expression involving the cast. */
916 look_for_casts (tree lhs
__attribute__((unused
)), tree t
)
918 if (is_gimple_cast (t
) || TREE_CODE (t
) == VIEW_CONVERT_EXPR
)
920 tree castfromvar
= TREE_OPERAND (t
, 0);
921 check_cast (TREE_TYPE (t
), castfromvar
);
923 else if (TREE_CODE (t
) == COMPONENT_REF
924 || TREE_CODE (t
) == INDIRECT_REF
925 || TREE_CODE (t
) == BIT_FIELD_REF
)
927 tree base
= get_base_address (t
);
930 t
= TREE_OPERAND (t
, 0);
931 if (TREE_CODE (t
) == VIEW_CONVERT_EXPR
)
933 /* This may be some part of a component ref.
934 IE it may be a.b.VIEW_CONVERT_EXPR<weird_type>(c).d, AFAIK.
935 castfromref will give you a.b.c, not a. */
936 tree castfromref
= TREE_OPERAND (t
, 0);
937 check_cast (TREE_TYPE (t
), castfromref
);
939 else if (TREE_CODE (t
) == COMPONENT_REF
)
940 get_canon_type (TREE_TYPE (TREE_OPERAND (t
, 1)), false, false);
945 /* Check to see if T is a read or address of operation on a static var
946 we are interested in analyzing. */
949 check_rhs_var (tree t
)
951 look_for_address_of (t
);
955 /* Check to see if T is an assignment to a static var we are
956 interested in analyzing. */
959 check_lhs_var (tree t
)
964 /* This is a scaled down version of get_asm_expr_operands from
965 tree_ssa_operands.c. The version there runs much later and assumes
966 that aliasing information is already available. Here we are just
967 trying to find if the set of inputs and outputs contain references
968 or address of operations to local. FN is the function being
969 analyzed and STMT is the actual asm statement. */
972 get_asm_expr_operands (tree stmt
)
974 int noutputs
= list_length (ASM_OUTPUTS (stmt
));
975 const char **oconstraints
976 = (const char **) alloca ((noutputs
) * sizeof (const char *));
979 const char *constraint
;
980 bool allows_mem
, allows_reg
, is_inout
;
982 for (i
=0, link
= ASM_OUTPUTS (stmt
); link
; ++i
, link
= TREE_CHAIN (link
))
984 oconstraints
[i
] = constraint
985 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
986 parse_output_constraint (&constraint
, i
, 0, 0,
987 &allows_mem
, &allows_reg
, &is_inout
);
989 check_lhs_var (TREE_VALUE (link
));
992 for (link
= ASM_INPUTS (stmt
); link
; link
= TREE_CHAIN (link
))
995 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link
)));
996 parse_input_constraint (&constraint
, 0, 0, noutputs
, 0,
997 oconstraints
, &allows_mem
, &allows_reg
);
999 check_rhs_var (TREE_VALUE (link
));
1002 /* There is no code here to check for asm memory clobbers. The
1003 casual maintainer might think that such code would be necessary,
1004 but that appears to be wrong. In other parts of the compiler,
1005 the asm memory clobbers are assumed to only clobber variables
1006 that are addressable. All types with addressable instances are
1007 assumed to already escape. So, we are protected here. */
1010 /* Check the parameters of a function call to CALL_EXPR to mark the
1011 types that pass across the function boundary. Also check to see if
1012 this is either an indirect call, a call outside the compilation
1016 check_call (tree call_expr
)
1018 int flags
= call_expr_flags(call_expr
);
1019 tree operand_list
= TREE_OPERAND (call_expr
, 1);
1021 tree callee_t
= get_callee_fndecl (call_expr
);
1023 struct cgraph_node
* callee
;
1024 enum availability avail
= AVAIL_NOT_AVAILABLE
;
1026 for (operand
= operand_list
;
1027 operand
!= NULL_TREE
;
1028 operand
= TREE_CHAIN (operand
))
1030 tree argument
= TREE_VALUE (operand
);
1031 check_rhs_var (argument
);
1037 tree last_arg_type
= NULL
;
1038 callee
= cgraph_node(callee_t
);
1039 avail
= cgraph_function_body_availability (callee
);
1041 /* Check that there are no implicit casts in the passing of
1043 if (TYPE_ARG_TYPES (TREE_TYPE (callee_t
)))
1045 operand
= operand_list
;
1046 for (arg_type
= TYPE_ARG_TYPES (TREE_TYPE (callee_t
));
1047 arg_type
&& TREE_VALUE (arg_type
) != void_type_node
;
1048 arg_type
= TREE_CHAIN (arg_type
))
1052 argument
= TREE_VALUE (operand
);
1053 last_arg_type
= TREE_VALUE(arg_type
);
1054 check_cast (last_arg_type
, argument
);
1055 operand
= TREE_CHAIN (operand
);
1058 /* The code reaches here for some unfortunate
1059 builtin functions that do not have a list of
1066 /* FIXME - According to Geoff Keating, we should never
1067 have to do this; the front ends should always process
1068 the arg list from the TYPE_ARG_LIST. */
1069 operand
= operand_list
;
1070 for (arg_type
= DECL_ARGUMENTS (callee_t
);
1072 arg_type
= TREE_CHAIN (arg_type
))
1076 argument
= TREE_VALUE (operand
);
1077 last_arg_type
= TREE_TYPE(arg_type
);
1078 check_cast (last_arg_type
, argument
);
1079 operand
= TREE_CHAIN (operand
);
1082 /* The code reaches here for some unfortunate
1083 builtin functions that do not have a list of
1089 /* In the case where we have a var_args function, we need to
1090 check the remaining parameters against the last argument. */
1091 arg_type
= last_arg_type
;
1093 operand
!= NULL_TREE
;
1094 operand
= TREE_CHAIN (operand
))
1096 argument
= TREE_VALUE (operand
);
1098 check_cast (arg_type
, argument
);
1101 /* The code reaches here for some unfortunate
1102 builtin functions that do not have a list of
1103 argument types. Most of these functions have
1104 been marked as having their parameters not
1105 escape, but for the rest, the type is doomed. */
1106 tree type
= get_canon_type (TREE_TYPE (argument
), false, false);
1107 mark_interesting_type (type
, FULL_ESCAPE
);
1112 /* The callee is either unknown (indirect call) or there is just no
1113 scannable code for it (external call) . We look to see if there
1114 are any bits available for the callee (such as by declaration or
1115 because it is builtin) and process solely on the basis of those
1118 if (avail
== AVAIL_NOT_AVAILABLE
|| avail
== AVAIL_OVERWRITABLE
)
1120 /* If this is a direct call to an external function, mark all of
1121 the parameter and return types. */
1122 for (operand
= operand_list
;
1123 operand
!= NULL_TREE
;
1124 operand
= TREE_CHAIN (operand
))
1127 get_canon_type (TREE_TYPE (TREE_VALUE (operand
)), false, false);
1128 mark_interesting_type (type
, EXPOSED_PARAMETER
);
1134 get_canon_type (TREE_TYPE (TREE_TYPE (callee_t
)), false, false);
1135 mark_interesting_type (type
, EXPOSED_PARAMETER
);
1138 return (flags
& ECF_MALLOC
);
1141 /* CODE is the operation on OP0 and OP1. OP0 is the operand that we
1142 *know* is a pointer type. OP1 may be a pointer type. */
1144 okay_pointer_operation (enum tree_code code
, tree op0
, tree op1
)
1146 tree op0type
= TYPE_MAIN_VARIANT (TREE_TYPE (op0
));
1147 tree op1type
= TYPE_MAIN_VARIANT (TREE_TYPE (op1
));
1148 if (POINTER_TYPE_P (op1type
))
1155 /* TODO: Handle multiples of op0 size as well */
1156 if (operand_equal_p (size_in_bytes (op0type
), op1
, 0))
1166 /* TP is the part of the tree currently under the microscope.
1167 WALK_SUBTREES is part of the walk_tree api but is unused here.
1168 DATA is cgraph_node of the function being walked. */
1170 /* FIXME: When this is converted to run over SSA form, this code
1171 should be converted to use the operand scanner. */
1174 scan_for_refs (tree
*tp
, int *walk_subtrees
, void *data
)
1176 struct cgraph_node
*fn
= data
;
1179 switch (TREE_CODE (t
))
1182 if (DECL_INITIAL (t
))
1183 walk_tree (&DECL_INITIAL (t
), scan_for_refs
, fn
, visited_nodes
);
1187 case GIMPLE_MODIFY_STMT
:
1189 /* First look on the lhs and see what variable is stored to */
1190 tree lhs
= GIMPLE_STMT_OPERAND (t
, 0);
1191 tree rhs
= GIMPLE_STMT_OPERAND (t
, 1);
1193 check_lhs_var (lhs
);
1194 check_cast (TREE_TYPE (lhs
), rhs
);
1196 /* For the purposes of figuring out what the cast affects */
1198 /* Next check the operands on the rhs to see if they are ok. */
1199 switch (TREE_CODE_CLASS (TREE_CODE (rhs
)))
1203 tree op0
= TREE_OPERAND (rhs
, 0);
1204 tree type0
= get_canon_type (TREE_TYPE (op0
), false, false);
1205 tree op1
= TREE_OPERAND (rhs
, 1);
1206 tree type1
= get_canon_type (TREE_TYPE (op1
), false, false);
1208 /* If this is pointer arithmetic of any bad sort, then
1209 we need to mark the types as bad. For binary
1210 operations, no binary operator we currently support
1211 is always "safe" in regard to what it would do to
1212 pointers for purposes of determining which types
1213 escape, except operations of the size of the type.
1214 It is possible that min and max under the right set
1215 of circumstances and if the moon is in the correct
1216 place could be safe, but it is hard to see how this
1217 is worth the effort. */
1219 if (type0
&& POINTER_TYPE_P (type0
)
1220 && !okay_pointer_operation (TREE_CODE (rhs
), op0
, op1
))
1221 mark_interesting_type (type0
, FULL_ESCAPE
);
1222 if (type1
&& POINTER_TYPE_P (type1
)
1223 && !okay_pointer_operation (TREE_CODE (rhs
), op1
, op0
))
1224 mark_interesting_type (type1
, FULL_ESCAPE
);
1226 look_for_casts (lhs
, op0
);
1227 look_for_casts (lhs
, op1
);
1228 check_rhs_var (op0
);
1229 check_rhs_var (op1
);
1234 tree op0
= TREE_OPERAND (rhs
, 0);
1235 tree type0
= get_canon_type (TREE_TYPE (op0
), false, false);
1236 /* For unary operations, if the operation is NEGATE or
1237 ABS on a pointer, this is also considered pointer
1238 arithmetic and thus, bad for business. */
1239 if (type0
&& (TREE_CODE (op0
) == NEGATE_EXPR
1240 || TREE_CODE (op0
) == ABS_EXPR
)
1241 && POINTER_TYPE_P (type0
))
1243 mark_interesting_type (type0
, FULL_ESCAPE
);
1245 check_rhs_var (op0
);
1246 look_for_casts (lhs
, op0
);
1247 look_for_casts (lhs
, rhs
);
1252 look_for_casts (lhs
, rhs
);
1253 check_rhs_var (rhs
);
1255 case tcc_declaration
:
1256 check_rhs_var (rhs
);
1258 case tcc_expression
:
1259 switch (TREE_CODE (rhs
))
1262 look_for_casts (lhs
, TREE_OPERAND (rhs
, 0));
1263 check_rhs_var (rhs
);
1266 /* If this is a call to malloc, squirrel away the
1267 result so we do mark the resulting cast as being
1269 if (check_call (rhs
))
1271 if (TREE_CODE (lhs
) == SSA_NAME
)
1272 lhs
= SSA_NAME_VAR (lhs
);
1273 bitmap_set_bit (results_of_malloc
, DECL_UID (lhs
));
1288 /* This case is here to find addresses on rhs of constructors in
1289 decl_initial of static variables. */
1300 get_asm_expr_operands (t
);
1311 /* The init routine for analyzing global static variable usage. See
1312 comments at top for description. */
1316 bitmap_obstack_initialize (&ipa_obstack
);
1317 global_types_exposed_parameter
= BITMAP_ALLOC (&ipa_obstack
);
1318 global_types_full_escape
= BITMAP_ALLOC (&ipa_obstack
);
1319 global_types_seen
= BITMAP_ALLOC (&ipa_obstack
);
1320 results_of_malloc
= BITMAP_ALLOC (&ipa_obstack
);
1322 uid_to_canon_type
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1323 all_canon_types
= splay_tree_new (compare_type_brand
, 0, 0);
1324 type_to_canon_type
= splay_tree_new (splay_tree_compare_pointers
, 0, 0);
1325 uid_to_subtype_map
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1326 uid_to_addressof_down_map
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1327 uid_to_addressof_up_map
= splay_tree_new (splay_tree_compare_ints
, 0, 0);
1329 /* There are some shared nodes, in particular the initializers on
1330 static declarations. We do not need to scan them more than once
1331 since all we would be interested in are the addressof
1333 visited_nodes
= pointer_set_create ();
1337 /* Check out the rhs of a static or global initialization VNODE to see
1338 if any of them contain addressof operations. Note that some of
1339 these variables may not even be referenced in the code in this
1340 compilation unit but their right hand sides may contain references
1341 to variables defined within this unit. */
1344 analyze_variable (struct varpool_node
*vnode
)
1346 tree global
= vnode
->decl
;
1347 tree type
= get_canon_type (TREE_TYPE (global
), false, false);
1349 /* If this variable has exposure beyond the compilation unit, add
1350 its type to the global types. */
1352 if (vnode
->externally_visible
)
1353 mark_interesting_type (type
, FULL_ESCAPE
);
1355 gcc_assert (TREE_CODE (global
) == VAR_DECL
);
1357 if (DECL_INITIAL (global
))
1358 walk_tree (&DECL_INITIAL (global
), scan_for_refs
, NULL
, visited_nodes
);
1361 /* This is the main routine for finding the reference patterns for
1362 global variables within a function FN. */
1365 analyze_function (struct cgraph_node
*fn
)
1367 tree decl
= fn
->decl
;
1368 check_function_parameter_and_return_types (decl
,
1369 fn
->local
.externally_visible
);
1371 fprintf (dump_file
, "\n local analysis of %s", cgraph_node_name (fn
));
1374 struct function
*this_cfun
= DECL_STRUCT_FUNCTION (decl
);
1375 basic_block this_block
;
1377 FOR_EACH_BB_FN (this_block
, this_cfun
)
1379 block_stmt_iterator bsi
;
1380 for (bsi
= bsi_start (this_block
); !bsi_end_p (bsi
); bsi_next (&bsi
))
1381 walk_tree (bsi_stmt_ptr (bsi
), scan_for_refs
,
1386 /* There may be const decls with interesting right hand sides. */
1387 if (DECL_STRUCT_FUNCTION (decl
))
1390 for (step
= DECL_STRUCT_FUNCTION (decl
)->unexpanded_var_list
;
1392 step
= TREE_CHAIN (step
))
1394 tree var
= TREE_VALUE (step
);
1395 if (TREE_CODE (var
) == VAR_DECL
1396 && DECL_INITIAL (var
)
1397 && !TREE_STATIC (var
))
1398 walk_tree (&DECL_INITIAL (var
), scan_for_refs
,
1400 get_canon_type (TREE_TYPE (var
), false, false);
1407 /* Convert a type_UID into a type. */
1409 type_for_uid (int uid
)
1411 splay_tree_node result
=
1412 splay_tree_lookup (uid_to_canon_type
, (splay_tree_key
) uid
);
1415 return (tree
) result
->value
;
1419 /* Return the a bitmap with the subtypes of the type for UID. If it
1420 does not exist, return either NULL or a new bitmap depending on the
1424 subtype_map_for_uid (int uid
, bool create
)
1426 splay_tree_node result
= splay_tree_lookup (uid_to_subtype_map
,
1427 (splay_tree_key
) uid
);
1430 return (bitmap
) result
->value
;
1433 bitmap subtype_map
= BITMAP_ALLOC (&ipa_obstack
);
1434 splay_tree_insert (uid_to_subtype_map
,
1436 (splay_tree_value
)subtype_map
);
1442 /* Mark all of the supertypes and field types of TYPE as being seen.
1443 Also accumulate the subtypes for each type so that
1444 close_types_full_escape can mark a subtype as escaping if the
1445 supertype escapes. */
1448 close_type_seen (tree type
)
1452 tree binfo
, base_binfo
;
1454 /* See thru all pointer tos and array ofs. */
1455 type
= get_canon_type (type
, true, true);
1459 uid
= TYPE_UID (type
);
1461 if (bitmap_bit_p (been_there_done_that
, uid
))
1463 bitmap_set_bit (been_there_done_that
, uid
);
1465 /* If we are doing a language with a type hierarchy, mark all of
1466 the superclasses. */
1467 if (TYPE_BINFO (type
))
1468 for (binfo
= TYPE_BINFO (type
), i
= 0;
1469 BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1471 tree binfo_type
= BINFO_TYPE (base_binfo
);
1472 bitmap subtype_map
= subtype_map_for_uid
1473 (TYPE_UID (TYPE_MAIN_VARIANT (binfo_type
)), true);
1474 bitmap_set_bit (subtype_map
, uid
);
1475 close_type_seen (get_canon_type (binfo_type
, true, true));
1478 /* If the field is a struct or union type, mark all of the
1480 for (field
= TYPE_FIELDS (type
);
1482 field
= TREE_CHAIN (field
))
1485 if (TREE_CODE (field
) != FIELD_DECL
)
1488 field_type
= TREE_TYPE (field
);
1489 if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type
) >= 0)
1490 close_type_seen (get_canon_type (field_type
, true, true));
1494 /* Take a TYPE that has been passed by value to an external function
1495 and mark all of the fields that have pointer types as escaping. For
1496 any of the non pointer types that are structures or unions,
1497 recurse. TYPE is never a pointer type. */
1500 close_type_exposed_parameter (tree type
)
1505 type
= get_canon_type (type
, false, false);
1508 uid
= TYPE_UID (type
);
1509 gcc_assert (!POINTER_TYPE_P (type
));
1511 if (bitmap_bit_p (been_there_done_that
, uid
))
1513 bitmap_set_bit (been_there_done_that
, uid
);
1515 /* If the field is a struct or union type, mark all of the
1517 for (field
= TYPE_FIELDS (type
);
1519 field
= TREE_CHAIN (field
))
1523 if (TREE_CODE (field
) != FIELD_DECL
)
1526 field_type
= get_canon_type (TREE_TYPE (field
), false, false);
1527 mark_interesting_type (field_type
, EXPOSED_PARAMETER
);
1529 /* Only recurse for non pointer types of structures and unions. */
1530 if (ipa_type_escape_star_count_of_interesting_type (field_type
) == 0)
1531 close_type_exposed_parameter (field_type
);
1535 /* The next function handles the case where a type fully escapes.
1536 This means that not only does the type itself escape,
1538 a) the type of every field recursively escapes
1539 b) the type of every subtype escapes as well as the super as well
1540 as all of the pointer to types for each field.
1542 Note that pointer to types are not marked as escaping. If the
1543 pointed to type escapes, the pointer to type also escapes.
1545 Take a TYPE that has had the address taken for an instance of it
1546 and mark all of the types for its fields as having their addresses
1550 close_type_full_escape (tree type
)
1555 tree binfo
, base_binfo
;
1558 splay_tree_node address_result
;
1560 /* Strip off any pointer or array types. */
1561 type
= get_canon_type (type
, true, true);
1564 uid
= TYPE_UID (type
);
1566 if (bitmap_bit_p (been_there_done_that
, uid
))
1568 bitmap_set_bit (been_there_done_that
, uid
);
1570 subtype_map
= subtype_map_for_uid (uid
, false);
1572 /* If we are doing a language with a type hierarchy, mark all of
1573 the superclasses. */
1574 if (TYPE_BINFO (type
))
1575 for (binfo
= TYPE_BINFO (type
), i
= 0;
1576 BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1578 tree binfotype
= BINFO_TYPE (base_binfo
);
1579 binfotype
= mark_type (binfotype
, FULL_ESCAPE
);
1580 close_type_full_escape (binfotype
);
1583 /* Mark as escaped any types that have been down casted to
1586 EXECUTE_IF_SET_IN_BITMAP (subtype_map
, 0, i
, bi
)
1588 tree subtype
= type_for_uid (i
);
1589 subtype
= mark_type (subtype
, FULL_ESCAPE
);
1590 close_type_full_escape (subtype
);
1593 /* If the field is a struct or union type, mark all of the
1595 for (field
= TYPE_FIELDS (type
);
1597 field
= TREE_CHAIN (field
))
1600 if (TREE_CODE (field
) != FIELD_DECL
)
1603 field_type
= TREE_TYPE (field
);
1604 if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type
) >= 0)
1606 field_type
= mark_type (field_type
, FULL_ESCAPE
);
1607 close_type_full_escape (field_type
);
1611 /* For all of the types A that contain this type B and were part of
1612 an expression like "&...A.B...", mark the A's as escaping. */
1613 address_result
= splay_tree_lookup (uid_to_addressof_up_map
,
1614 (splay_tree_key
) uid
);
1617 bitmap containing_classes
= (bitmap
) address_result
->value
;
1618 EXECUTE_IF_SET_IN_BITMAP (containing_classes
, 0, i
, bi
)
1620 close_type_full_escape (type_for_uid (i
));
1625 /* Transitively close the addressof bitmap for the type with UID.
1626 This means that if we had a.b and b.c, a would have both b and c in
1630 close_addressof_down (int uid
)
1633 splay_tree_node result
=
1634 splay_tree_lookup (uid_to_addressof_down_map
, (splay_tree_key
) uid
);
1640 map
= (bitmap
) result
->value
;
1644 if (bitmap_bit_p (been_there_done_that
, uid
))
1646 bitmap_set_bit (been_there_done_that
, uid
);
1648 /* If the type escapes, get rid of the addressof map, it will not be
1650 if (bitmap_bit_p (global_types_full_escape
, uid
))
1653 splay_tree_remove (uid_to_addressof_down_map
, (splay_tree_key
) uid
);
1657 /* The new_map will have all of the bits for the enclosed fields and
1658 will have the unique id version of the old map. */
1659 new_map
= BITMAP_ALLOC (&ipa_obstack
);
1661 EXECUTE_IF_SET_IN_BITMAP (map
, 0, i
, bi
)
1663 bitmap submap
= close_addressof_down (i
);
1664 bitmap_set_bit (new_map
, i
);
1666 bitmap_ior_into (new_map
, submap
);
1668 result
->value
= (splay_tree_value
) new_map
;
1675 /* The main entry point for type escape analysis. */
1678 type_escape_execute (void)
1680 struct cgraph_node
*node
;
1681 struct varpool_node
*vnode
;
1684 splay_tree_node result
;
1688 /* Process all of the variables first. */
1689 FOR_EACH_STATIC_VARIABLE (vnode
)
1690 analyze_variable (vnode
);
1692 /* Process all of the functions. next
1694 We do not want to process any of the clones so we check that this
1695 is a master clone. However, we do need to process any
1696 AVAIL_OVERWRITABLE functions (these are never clones) because
1697 they may cause a type variable to escape.
1699 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1701 && (cgraph_is_master_clone (node
)
1702 || (cgraph_function_body_availability (node
) == AVAIL_OVERWRITABLE
)))
1703 analyze_function (node
);
1706 pointer_set_destroy (visited_nodes
);
1707 visited_nodes
= NULL
;
1709 /* Do all of the closures to discover which types escape the
1710 compilation unit. */
1712 been_there_done_that
= BITMAP_ALLOC (&ipa_obstack
);
1713 bitmap_tmp
= BITMAP_ALLOC (&ipa_obstack
);
1715 /* Examine the types that we have directly seen in scanning the code
1716 and add to that any contained types or superclasses. */
1718 bitmap_copy (bitmap_tmp
, global_types_seen
);
1719 EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp
, 0, i
, bi
)
1721 tree type
= type_for_uid (i
);
1722 /* Only look at records and unions and pointer tos. */
1723 if (ipa_type_escape_star_count_of_interesting_or_array_type (type
) >= 0)
1724 close_type_seen (type
);
1726 bitmap_clear (been_there_done_that
);
1728 /* Examine all of the types passed by value and mark any enclosed
1729 pointer types as escaping. */
1730 bitmap_copy (bitmap_tmp
, global_types_exposed_parameter
);
1731 EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp
, 0, i
, bi
)
1733 close_type_exposed_parameter (type_for_uid (i
));
1735 bitmap_clear (been_there_done_that
);
1737 /* Close the types for escape. If something escapes, then any
1738 enclosed types escape as well as any subtypes. */
1739 bitmap_copy (bitmap_tmp
, global_types_full_escape
);
1740 EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp
, 0, i
, bi
)
1742 close_type_full_escape (type_for_uid (i
));
1744 bitmap_clear (been_there_done_that
);
1746 /* Before this pass, the uid_to_addressof_down_map for type X
1747 contained an entry for Y if there had been an operation of the
1748 form &X.Y. This step adds all of the fields contained within Y
1749 (recursively) to X's map. */
1751 result
= splay_tree_min (uid_to_addressof_down_map
);
1754 int uid
= result
->key
;
1755 /* Close the addressof map, i.e. copy all of the transitive
1756 substructures up to this level. */
1757 close_addressof_down (uid
);
1758 result
= splay_tree_successor (uid_to_addressof_down_map
, uid
);
1761 /* Do not need the array types and pointer types in the persistent
1763 result
= splay_tree_min (all_canon_types
);
1766 tree type
= (tree
) result
->value
;
1767 tree key
= (tree
) result
->key
;
1768 if (POINTER_TYPE_P (type
)
1769 || TREE_CODE (type
) == ARRAY_TYPE
)
1771 splay_tree_remove (all_canon_types
, (splay_tree_key
) result
->key
);
1772 splay_tree_remove (type_to_canon_type
, (splay_tree_key
) type
);
1773 splay_tree_remove (uid_to_canon_type
, (splay_tree_key
) TYPE_UID (type
));
1774 bitmap_clear_bit (global_types_seen
, TYPE_UID (type
));
1776 result
= splay_tree_successor (all_canon_types
, (splay_tree_key
) key
);
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");
1796 /* Get rid of uid_to_addressof_up_map and its bitmaps. */
1797 result
= splay_tree_min (uid_to_addressof_up_map
);
1800 int uid
= (int)result
->key
;
1801 bitmap bm
= (bitmap
)result
->value
;
1804 splay_tree_remove (uid_to_addressof_up_map
, (splay_tree_key
) uid
);
1805 result
= splay_tree_successor (uid_to_addressof_up_map
, uid
);
1808 /* Get rid of the subtype map. */
1809 result
= splay_tree_min (uid_to_subtype_map
);
1812 bitmap b
= (bitmap
)result
->value
;
1814 splay_tree_remove (uid_to_subtype_map
, result
->key
);
1815 result
= splay_tree_min (uid_to_subtype_map
);
1817 splay_tree_delete (uid_to_subtype_map
);
1818 uid_to_subtype_map
= NULL
;
1820 BITMAP_FREE (global_types_exposed_parameter
);
1821 BITMAP_FREE (been_there_done_that
);
1822 BITMAP_FREE (bitmap_tmp
);
1823 BITMAP_FREE (results_of_malloc
);
1828 gate_type_escape_vars (void)
1830 return (flag_unit_at_a_time
!= 0 && flag_ipa_type_escape
1831 /* Don't bother doing anything if the program has errors. */
1832 && !(errorcount
|| sorrycount
));
1835 struct tree_opt_pass pass_ipa_type_escape
=
1837 "type-escape-var", /* name */
1838 gate_type_escape_vars
, /* gate */
1839 type_escape_execute
, /* execute */
1842 0, /* static_pass_number */
1843 TV_IPA_TYPE_ESCAPE
, /* tv_id */
1844 0, /* properties_required */
1845 0, /* properties_provided */
1846 0, /* properties_destroyed */
1847 0, /* todo_flags_start */
1848 0, /* todo_flags_finish */