1 /* Exception handling semantics and decomposition for trees.
2 Copyright (C) 2003-2013 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
22 #include "coretypes.h"
23 #include "hash-table.h"
29 #include "pointer-set.h"
31 #include "tree-inline.h"
32 #include "tree-pass.h"
33 #include "langhooks.h"
35 #include "diagnostic-core.h"
40 /* In some instances a tree and a gimple need to be stored in a same table,
41 i.e. in hash tables. This is a structure to do this. */
42 typedef union {tree
*tp
; tree t
; gimple g
;} treemple
;
44 /* Nonzero if we are using EH to handle cleanups. */
45 static int using_eh_for_cleanups_p
= 0;
48 using_eh_for_cleanups (void)
50 using_eh_for_cleanups_p
= 1;
53 /* Misc functions used in this file. */
55 /* Remember and lookup EH landing pad data for arbitrary statements.
56 Really this means any statement that could_throw_p. We could
57 stuff this information into the stmt_ann data structure, but:
59 (1) We absolutely rely on this information being kept until
60 we get to rtl. Once we're done with lowering here, if we lose
61 the information there's no way to recover it!
63 (2) There are many more statements that *cannot* throw as
64 compared to those that can. We should be saving some amount
65 of space by only allocating memory for those that can throw. */
67 /* Add statement T in function IFUN to landing pad NUM. */
70 add_stmt_to_eh_lp_fn (struct function
*ifun
, gimple t
, int num
)
72 struct throw_stmt_node
*n
;
75 gcc_assert (num
!= 0);
77 n
= ggc_alloc_throw_stmt_node ();
81 if (!get_eh_throw_stmt_table (ifun
))
82 set_eh_throw_stmt_table (ifun
, htab_create_ggc (31, struct_ptr_hash
,
86 slot
= htab_find_slot (get_eh_throw_stmt_table (ifun
), n
, INSERT
);
91 /* Add statement T in the current function (cfun) to EH landing pad NUM. */
94 add_stmt_to_eh_lp (gimple t
, int num
)
96 add_stmt_to_eh_lp_fn (cfun
, t
, num
);
99 /* Add statement T to the single EH landing pad in REGION. */
102 record_stmt_eh_region (eh_region region
, gimple t
)
106 if (region
->type
== ERT_MUST_NOT_THROW
)
107 add_stmt_to_eh_lp_fn (cfun
, t
, -region
->index
);
110 eh_landing_pad lp
= region
->landing_pads
;
112 lp
= gen_eh_landing_pad (region
);
114 gcc_assert (lp
->next_lp
== NULL
);
115 add_stmt_to_eh_lp_fn (cfun
, t
, lp
->index
);
120 /* Remove statement T in function IFUN from its EH landing pad. */
123 remove_stmt_from_eh_lp_fn (struct function
*ifun
, gimple t
)
125 struct throw_stmt_node dummy
;
128 if (!get_eh_throw_stmt_table (ifun
))
132 slot
= htab_find_slot (get_eh_throw_stmt_table (ifun
), &dummy
,
136 htab_clear_slot (get_eh_throw_stmt_table (ifun
), slot
);
144 /* Remove statement T in the current function (cfun) from its
148 remove_stmt_from_eh_lp (gimple t
)
150 return remove_stmt_from_eh_lp_fn (cfun
, t
);
153 /* Determine if statement T is inside an EH region in function IFUN.
154 Positive numbers indicate a landing pad index; negative numbers
155 indicate a MUST_NOT_THROW region index; zero indicates that the
156 statement is not recorded in the region table. */
159 lookup_stmt_eh_lp_fn (struct function
*ifun
, gimple t
)
161 struct throw_stmt_node
*p
, n
;
163 if (ifun
->eh
->throw_stmt_table
== NULL
)
167 p
= (struct throw_stmt_node
*) htab_find (ifun
->eh
->throw_stmt_table
, &n
);
168 return p
? p
->lp_nr
: 0;
171 /* Likewise, but always use the current function. */
174 lookup_stmt_eh_lp (gimple t
)
176 /* We can get called from initialized data when -fnon-call-exceptions
177 is on; prevent crash. */
180 return lookup_stmt_eh_lp_fn (cfun
, t
);
183 /* First pass of EH node decomposition. Build up a tree of GIMPLE_TRY_FINALLY
184 nodes and LABEL_DECL nodes. We will use this during the second phase to
185 determine if a goto leaves the body of a TRY_FINALLY_EXPR node. */
187 struct finally_tree_node
189 /* When storing a GIMPLE_TRY, we have to record a gimple. However
190 when deciding whether a GOTO to a certain LABEL_DECL (which is a
191 tree) leaves the TRY block, its necessary to record a tree in
192 this field. Thus a treemple is used. */
197 /* Hashtable helpers. */
199 struct finally_tree_hasher
: typed_free_remove
<finally_tree_node
>
201 typedef finally_tree_node value_type
;
202 typedef finally_tree_node compare_type
;
203 static inline hashval_t
hash (const value_type
*);
204 static inline bool equal (const value_type
*, const compare_type
*);
208 finally_tree_hasher::hash (const value_type
*v
)
210 return (intptr_t)v
->child
.t
>> 4;
214 finally_tree_hasher::equal (const value_type
*v
, const compare_type
*c
)
216 return v
->child
.t
== c
->child
.t
;
219 /* Note that this table is *not* marked GTY. It is short-lived. */
220 static hash_table
<finally_tree_hasher
> finally_tree
;
223 record_in_finally_tree (treemple child
, gimple parent
)
225 struct finally_tree_node
*n
;
226 finally_tree_node
**slot
;
228 n
= XNEW (struct finally_tree_node
);
232 slot
= finally_tree
.find_slot (n
, INSERT
);
238 collect_finally_tree (gimple stmt
, gimple region
);
240 /* Go through the gimple sequence. Works with collect_finally_tree to
241 record all GIMPLE_LABEL and GIMPLE_TRY statements. */
244 collect_finally_tree_1 (gimple_seq seq
, gimple region
)
246 gimple_stmt_iterator gsi
;
248 for (gsi
= gsi_start (seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
249 collect_finally_tree (gsi_stmt (gsi
), region
);
253 collect_finally_tree (gimple stmt
, gimple region
)
257 switch (gimple_code (stmt
))
260 temp
.t
= gimple_label_label (stmt
);
261 record_in_finally_tree (temp
, region
);
265 if (gimple_try_kind (stmt
) == GIMPLE_TRY_FINALLY
)
268 record_in_finally_tree (temp
, region
);
269 collect_finally_tree_1 (gimple_try_eval (stmt
), stmt
);
270 collect_finally_tree_1 (gimple_try_cleanup (stmt
), region
);
272 else if (gimple_try_kind (stmt
) == GIMPLE_TRY_CATCH
)
274 collect_finally_tree_1 (gimple_try_eval (stmt
), region
);
275 collect_finally_tree_1 (gimple_try_cleanup (stmt
), region
);
280 collect_finally_tree_1 (gimple_catch_handler (stmt
), region
);
283 case GIMPLE_EH_FILTER
:
284 collect_finally_tree_1 (gimple_eh_filter_failure (stmt
), region
);
288 collect_finally_tree_1 (gimple_eh_else_n_body (stmt
), region
);
289 collect_finally_tree_1 (gimple_eh_else_e_body (stmt
), region
);
293 /* A type, a decl, or some kind of statement that we're not
294 interested in. Don't walk them. */
300 /* Use the finally tree to determine if a jump from START to TARGET
301 would leave the try_finally node that START lives in. */
304 outside_finally_tree (treemple start
, gimple target
)
306 struct finally_tree_node n
, *p
;
311 p
= finally_tree
.find (&n
);
316 while (start
.g
!= target
);
321 /* Second pass of EH node decomposition. Actually transform the GIMPLE_TRY
322 nodes into a set of gotos, magic labels, and eh regions.
323 The eh region creation is straight-forward, but frobbing all the gotos
324 and such into shape isn't. */
326 /* The sequence into which we record all EH stuff. This will be
327 placed at the end of the function when we're all done. */
328 static gimple_seq eh_seq
;
330 /* Record whether an EH region contains something that can throw,
331 indexed by EH region number. */
332 static bitmap eh_region_may_contain_throw_map
;
334 /* The GOTO_QUEUE is is an array of GIMPLE_GOTO and GIMPLE_RETURN
335 statements that are seen to escape this GIMPLE_TRY_FINALLY node.
336 The idea is to record a gimple statement for everything except for
337 the conditionals, which get their labels recorded. Since labels are
338 of type 'tree', we need this node to store both gimple and tree
339 objects. REPL_STMT is the sequence used to replace the goto/return
340 statement. CONT_STMT is used to store the statement that allows
341 the return/goto to jump to the original destination. */
343 struct goto_queue_node
347 gimple_seq repl_stmt
;
350 /* This is used when index >= 0 to indicate that stmt is a label (as
351 opposed to a goto stmt). */
355 /* State of the world while lowering. */
359 /* What's "current" while constructing the eh region tree. These
360 correspond to variables of the same name in cfun->eh, which we
361 don't have easy access to. */
362 eh_region cur_region
;
364 /* What's "current" for the purposes of __builtin_eh_pointer. For
365 a CATCH, this is the associated TRY. For an EH_FILTER, this is
366 the associated ALLOWED_EXCEPTIONS, etc. */
367 eh_region ehp_region
;
369 /* Processing of TRY_FINALLY requires a bit more state. This is
370 split out into a separate structure so that we don't have to
371 copy so much when processing other nodes. */
372 struct leh_tf_state
*tf
;
377 /* Pointer to the GIMPLE_TRY_FINALLY node under discussion. The
378 try_finally_expr is the original GIMPLE_TRY_FINALLY. We need to retain
379 this so that outside_finally_tree can reliably reference the tree used
380 in the collect_finally_tree data structures. */
381 gimple try_finally_expr
;
384 /* While lowering a top_p usually it is expanded into multiple statements,
385 thus we need the following field to store them. */
386 gimple_seq top_p_seq
;
388 /* The state outside this try_finally node. */
389 struct leh_state
*outer
;
391 /* The exception region created for it. */
394 /* The goto queue. */
395 struct goto_queue_node
*goto_queue
;
396 size_t goto_queue_size
;
397 size_t goto_queue_active
;
399 /* Pointer map to help in searching goto_queue when it is large. */
400 struct pointer_map_t
*goto_queue_map
;
402 /* The set of unique labels seen as entries in the goto queue. */
403 vec
<tree
> dest_array
;
405 /* A label to be added at the end of the completed transformed
406 sequence. It will be set if may_fallthru was true *at one time*,
407 though subsequent transformations may have cleared that flag. */
410 /* True if it is possible to fall out the bottom of the try block.
411 Cleared if the fallthru is converted to a goto. */
414 /* True if any entry in goto_queue is a GIMPLE_RETURN. */
417 /* True if the finally block can receive an exception edge.
418 Cleared if the exception case is handled by code duplication. */
422 static gimple_seq
lower_eh_must_not_throw (struct leh_state
*, gimple
);
424 /* Search for STMT in the goto queue. Return the replacement,
425 or null if the statement isn't in the queue. */
427 #define LARGE_GOTO_QUEUE 20
429 static void lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*seq
);
432 find_goto_replacement (struct leh_tf_state
*tf
, treemple stmt
)
437 if (tf
->goto_queue_active
< LARGE_GOTO_QUEUE
)
439 for (i
= 0; i
< tf
->goto_queue_active
; i
++)
440 if ( tf
->goto_queue
[i
].stmt
.g
== stmt
.g
)
441 return tf
->goto_queue
[i
].repl_stmt
;
445 /* If we have a large number of entries in the goto_queue, create a
446 pointer map and use that for searching. */
448 if (!tf
->goto_queue_map
)
450 tf
->goto_queue_map
= pointer_map_create ();
451 for (i
= 0; i
< tf
->goto_queue_active
; i
++)
453 slot
= pointer_map_insert (tf
->goto_queue_map
,
454 tf
->goto_queue
[i
].stmt
.g
);
455 gcc_assert (*slot
== NULL
);
456 *slot
= &tf
->goto_queue
[i
];
460 slot
= pointer_map_contains (tf
->goto_queue_map
, stmt
.g
);
462 return (((struct goto_queue_node
*) *slot
)->repl_stmt
);
467 /* A subroutine of replace_goto_queue_1. Handles the sub-clauses of a
468 lowered GIMPLE_COND. If, by chance, the replacement is a simple goto,
469 then we can just splat it in, otherwise we add the new stmts immediately
470 after the GIMPLE_COND and redirect. */
473 replace_goto_queue_cond_clause (tree
*tp
, struct leh_tf_state
*tf
,
474 gimple_stmt_iterator
*gsi
)
479 location_t loc
= gimple_location (gsi_stmt (*gsi
));
482 new_seq
= find_goto_replacement (tf
, temp
);
486 if (gimple_seq_singleton_p (new_seq
)
487 && gimple_code (gimple_seq_first_stmt (new_seq
)) == GIMPLE_GOTO
)
489 *tp
= gimple_goto_dest (gimple_seq_first_stmt (new_seq
));
493 label
= create_artificial_label (loc
);
494 /* Set the new label for the GIMPLE_COND */
497 gsi_insert_after (gsi
, gimple_build_label (label
), GSI_CONTINUE_LINKING
);
498 gsi_insert_seq_after (gsi
, gimple_seq_copy (new_seq
), GSI_CONTINUE_LINKING
);
501 /* The real work of replace_goto_queue. Returns with TSI updated to
502 point to the next statement. */
504 static void replace_goto_queue_stmt_list (gimple_seq
*, struct leh_tf_state
*);
507 replace_goto_queue_1 (gimple stmt
, struct leh_tf_state
*tf
,
508 gimple_stmt_iterator
*gsi
)
514 switch (gimple_code (stmt
))
519 seq
= find_goto_replacement (tf
, temp
);
522 gsi_insert_seq_before (gsi
, gimple_seq_copy (seq
), GSI_SAME_STMT
);
523 gsi_remove (gsi
, false);
529 replace_goto_queue_cond_clause (gimple_op_ptr (stmt
, 2), tf
, gsi
);
530 replace_goto_queue_cond_clause (gimple_op_ptr (stmt
, 3), tf
, gsi
);
534 replace_goto_queue_stmt_list (gimple_try_eval_ptr (stmt
), tf
);
535 replace_goto_queue_stmt_list (gimple_try_cleanup_ptr (stmt
), tf
);
538 replace_goto_queue_stmt_list (gimple_catch_handler_ptr (stmt
), tf
);
540 case GIMPLE_EH_FILTER
:
541 replace_goto_queue_stmt_list (gimple_eh_filter_failure_ptr (stmt
), tf
);
544 replace_goto_queue_stmt_list (gimple_eh_else_n_body_ptr (stmt
), tf
);
545 replace_goto_queue_stmt_list (gimple_eh_else_e_body_ptr (stmt
), tf
);
549 /* These won't have gotos in them. */
556 /* A subroutine of replace_goto_queue. Handles GIMPLE_SEQ. */
559 replace_goto_queue_stmt_list (gimple_seq
*seq
, struct leh_tf_state
*tf
)
561 gimple_stmt_iterator gsi
= gsi_start (*seq
);
563 while (!gsi_end_p (gsi
))
564 replace_goto_queue_1 (gsi_stmt (gsi
), tf
, &gsi
);
567 /* Replace all goto queue members. */
570 replace_goto_queue (struct leh_tf_state
*tf
)
572 if (tf
->goto_queue_active
== 0)
574 replace_goto_queue_stmt_list (&tf
->top_p_seq
, tf
);
575 replace_goto_queue_stmt_list (&eh_seq
, tf
);
578 /* Add a new record to the goto queue contained in TF. NEW_STMT is the
579 data to be added, IS_LABEL indicates whether NEW_STMT is a label or
583 record_in_goto_queue (struct leh_tf_state
*tf
,
590 struct goto_queue_node
*q
;
592 gcc_assert (!tf
->goto_queue_map
);
594 active
= tf
->goto_queue_active
;
595 size
= tf
->goto_queue_size
;
598 size
= (size
? size
* 2 : 32);
599 tf
->goto_queue_size
= size
;
601 = XRESIZEVEC (struct goto_queue_node
, tf
->goto_queue
, size
);
604 q
= &tf
->goto_queue
[active
];
605 tf
->goto_queue_active
= active
+ 1;
607 memset (q
, 0, sizeof (*q
));
610 q
->location
= location
;
611 q
->is_label
= is_label
;
614 /* Record the LABEL label in the goto queue contained in TF.
618 record_in_goto_queue_label (struct leh_tf_state
*tf
, treemple stmt
, tree label
,
622 treemple temp
, new_stmt
;
627 /* Computed and non-local gotos do not get processed. Given
628 their nature we can neither tell whether we've escaped the
629 finally block nor redirect them if we knew. */
630 if (TREE_CODE (label
) != LABEL_DECL
)
633 /* No need to record gotos that don't leave the try block. */
635 if (!outside_finally_tree (temp
, tf
->try_finally_expr
))
638 if (! tf
->dest_array
.exists ())
640 tf
->dest_array
.create (10);
641 tf
->dest_array
.quick_push (label
);
646 int n
= tf
->dest_array
.length ();
647 for (index
= 0; index
< n
; ++index
)
648 if (tf
->dest_array
[index
] == label
)
651 tf
->dest_array
.safe_push (label
);
654 /* In the case of a GOTO we want to record the destination label,
655 since with a GIMPLE_COND we have an easy access to the then/else
658 record_in_goto_queue (tf
, new_stmt
, index
, true, location
);
661 /* For any GIMPLE_GOTO or GIMPLE_RETURN, decide whether it leaves a try_finally
662 node, and if so record that fact in the goto queue associated with that
666 maybe_record_in_goto_queue (struct leh_state
*state
, gimple stmt
)
668 struct leh_tf_state
*tf
= state
->tf
;
674 switch (gimple_code (stmt
))
677 new_stmt
.tp
= gimple_op_ptr (stmt
, 2);
678 record_in_goto_queue_label (tf
, new_stmt
, gimple_cond_true_label (stmt
),
679 EXPR_LOCATION (*new_stmt
.tp
));
680 new_stmt
.tp
= gimple_op_ptr (stmt
, 3);
681 record_in_goto_queue_label (tf
, new_stmt
, gimple_cond_false_label (stmt
),
682 EXPR_LOCATION (*new_stmt
.tp
));
686 record_in_goto_queue_label (tf
, new_stmt
, gimple_goto_dest (stmt
),
687 gimple_location (stmt
));
691 tf
->may_return
= true;
693 record_in_goto_queue (tf
, new_stmt
, -1, false, gimple_location (stmt
));
702 #ifdef ENABLE_CHECKING
703 /* We do not process GIMPLE_SWITCHes for now. As long as the original source
704 was in fact structured, and we've not yet done jump threading, then none
705 of the labels will leave outer GIMPLE_TRY_FINALLY nodes. Verify this. */
708 verify_norecord_switch_expr (struct leh_state
*state
, gimple switch_expr
)
710 struct leh_tf_state
*tf
= state
->tf
;
716 n
= gimple_switch_num_labels (switch_expr
);
718 for (i
= 0; i
< n
; ++i
)
721 tree lab
= CASE_LABEL (gimple_switch_label (switch_expr
, i
));
723 gcc_assert (!outside_finally_tree (temp
, tf
->try_finally_expr
));
727 #define verify_norecord_switch_expr(state, switch_expr)
730 /* Redirect a RETURN_EXPR pointed to by Q to FINLAB. If MOD is
731 non-null, insert it before the new branch. */
734 do_return_redirection (struct goto_queue_node
*q
, tree finlab
, gimple_seq mod
)
738 /* In the case of a return, the queue node must be a gimple statement. */
739 gcc_assert (!q
->is_label
);
741 /* Note that the return value may have already been computed, e.g.,
754 should return 0, not 1. We don't have to do anything to make
755 this happens because the return value has been placed in the
756 RESULT_DECL already. */
758 q
->cont_stmt
= q
->stmt
.g
;
761 gimple_seq_add_seq (&q
->repl_stmt
, mod
);
763 x
= gimple_build_goto (finlab
);
764 gimple_set_location (x
, q
->location
);
765 gimple_seq_add_stmt (&q
->repl_stmt
, x
);
768 /* Similar, but easier, for GIMPLE_GOTO. */
771 do_goto_redirection (struct goto_queue_node
*q
, tree finlab
, gimple_seq mod
,
772 struct leh_tf_state
*tf
)
776 gcc_assert (q
->is_label
);
778 q
->cont_stmt
= gimple_build_goto (tf
->dest_array
[q
->index
]);
781 gimple_seq_add_seq (&q
->repl_stmt
, mod
);
783 x
= gimple_build_goto (finlab
);
784 gimple_set_location (x
, q
->location
);
785 gimple_seq_add_stmt (&q
->repl_stmt
, x
);
788 /* Emit a standard landing pad sequence into SEQ for REGION. */
791 emit_post_landing_pad (gimple_seq
*seq
, eh_region region
)
793 eh_landing_pad lp
= region
->landing_pads
;
797 lp
= gen_eh_landing_pad (region
);
799 lp
->post_landing_pad
= create_artificial_label (UNKNOWN_LOCATION
);
800 EH_LANDING_PAD_NR (lp
->post_landing_pad
) = lp
->index
;
802 x
= gimple_build_label (lp
->post_landing_pad
);
803 gimple_seq_add_stmt (seq
, x
);
806 /* Emit a RESX statement into SEQ for REGION. */
809 emit_resx (gimple_seq
*seq
, eh_region region
)
811 gimple x
= gimple_build_resx (region
->index
);
812 gimple_seq_add_stmt (seq
, x
);
814 record_stmt_eh_region (region
->outer
, x
);
817 /* Emit an EH_DISPATCH statement into SEQ for REGION. */
820 emit_eh_dispatch (gimple_seq
*seq
, eh_region region
)
822 gimple x
= gimple_build_eh_dispatch (region
->index
);
823 gimple_seq_add_stmt (seq
, x
);
826 /* Note that the current EH region may contain a throw, or a
827 call to a function which itself may contain a throw. */
830 note_eh_region_may_contain_throw (eh_region region
)
832 while (bitmap_set_bit (eh_region_may_contain_throw_map
, region
->index
))
834 if (region
->type
== ERT_MUST_NOT_THROW
)
836 region
= region
->outer
;
842 /* Check if REGION has been marked as containing a throw. If REGION is
843 NULL, this predicate is false. */
846 eh_region_may_contain_throw (eh_region r
)
848 return r
&& bitmap_bit_p (eh_region_may_contain_throw_map
, r
->index
);
851 /* We want to transform
852 try { body; } catch { stuff; }
862 TP is a GIMPLE_TRY node. REGION is the region whose post_landing_pad
863 should be placed before the second operand, or NULL. OVER is
864 an existing label that should be put at the exit, or NULL. */
867 frob_into_branch_around (gimple tp
, eh_region region
, tree over
)
870 gimple_seq cleanup
, result
;
871 location_t loc
= gimple_location (tp
);
873 cleanup
= gimple_try_cleanup (tp
);
874 result
= gimple_try_eval (tp
);
877 emit_post_landing_pad (&eh_seq
, region
);
879 if (gimple_seq_may_fallthru (cleanup
))
882 over
= create_artificial_label (loc
);
883 x
= gimple_build_goto (over
);
884 gimple_set_location (x
, loc
);
885 gimple_seq_add_stmt (&cleanup
, x
);
887 gimple_seq_add_seq (&eh_seq
, cleanup
);
891 x
= gimple_build_label (over
);
892 gimple_seq_add_stmt (&result
, x
);
897 /* A subroutine of lower_try_finally. Duplicate the tree rooted at T.
898 Make sure to record all new labels found. */
901 lower_try_finally_dup_block (gimple_seq seq
, struct leh_state
*outer_state
,
904 gimple region
= NULL
;
906 gimple_stmt_iterator gsi
;
908 new_seq
= copy_gimple_seq_and_replace_locals (seq
);
910 for (gsi
= gsi_start (new_seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
912 gimple stmt
= gsi_stmt (gsi
);
913 if (LOCATION_LOCUS (gimple_location (stmt
)) == UNKNOWN_LOCATION
)
915 tree block
= gimple_block (stmt
);
916 gimple_set_location (stmt
, loc
);
917 gimple_set_block (stmt
, block
);
922 region
= outer_state
->tf
->try_finally_expr
;
923 collect_finally_tree_1 (new_seq
, region
);
928 /* A subroutine of lower_try_finally. Create a fallthru label for
929 the given try_finally state. The only tricky bit here is that
930 we have to make sure to record the label in our outer context. */
933 lower_try_finally_fallthru_label (struct leh_tf_state
*tf
)
935 tree label
= tf
->fallthru_label
;
940 label
= create_artificial_label (gimple_location (tf
->try_finally_expr
));
941 tf
->fallthru_label
= label
;
945 record_in_finally_tree (temp
, tf
->outer
->tf
->try_finally_expr
);
951 /* A subroutine of lower_try_finally. If FINALLY consits of a
952 GIMPLE_EH_ELSE node, return it. */
955 get_eh_else (gimple_seq finally
)
957 gimple x
= gimple_seq_first_stmt (finally
);
958 if (gimple_code (x
) == GIMPLE_EH_ELSE
)
960 gcc_assert (gimple_seq_singleton_p (finally
));
966 /* A subroutine of lower_try_finally. If the eh_protect_cleanup_actions
967 langhook returns non-null, then the language requires that the exception
968 path out of a try_finally be treated specially. To wit: the code within
969 the finally block may not itself throw an exception. We have two choices
970 here. First we can duplicate the finally block and wrap it in a
971 must_not_throw region. Second, we can generate code like
976 if (fintmp == eh_edge)
977 protect_cleanup_actions;
980 where "fintmp" is the temporary used in the switch statement generation
981 alternative considered below. For the nonce, we always choose the first
984 THIS_STATE may be null if this is a try-cleanup, not a try-finally. */
987 honor_protect_cleanup_actions (struct leh_state
*outer_state
,
988 struct leh_state
*this_state
,
989 struct leh_tf_state
*tf
)
991 tree protect_cleanup_actions
;
992 gimple_stmt_iterator gsi
;
993 bool finally_may_fallthru
;
997 /* First check for nothing to do. */
998 if (lang_hooks
.eh_protect_cleanup_actions
== NULL
)
1000 protect_cleanup_actions
= lang_hooks
.eh_protect_cleanup_actions ();
1001 if (protect_cleanup_actions
== NULL
)
1004 finally
= gimple_try_cleanup (tf
->top_p
);
1005 eh_else
= get_eh_else (finally
);
1007 /* Duplicate the FINALLY block. Only need to do this for try-finally,
1008 and not for cleanups. If we've got an EH_ELSE, extract it now. */
1011 finally
= gimple_eh_else_e_body (eh_else
);
1012 gimple_try_set_cleanup (tf
->top_p
, gimple_eh_else_n_body (eh_else
));
1014 else if (this_state
)
1015 finally
= lower_try_finally_dup_block (finally
, outer_state
,
1016 gimple_location (tf
->try_finally_expr
));
1017 finally_may_fallthru
= gimple_seq_may_fallthru (finally
);
1019 /* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP
1020 set, the handler of the TRY_CATCH_EXPR is another cleanup which ought
1021 to be in an enclosing scope, but needs to be implemented at this level
1022 to avoid a nesting violation (see wrap_temporary_cleanups in
1023 cp/decl.c). Since it's logically at an outer level, we should call
1024 terminate before we get to it, so strip it away before adding the
1025 MUST_NOT_THROW filter. */
1026 gsi
= gsi_start (finally
);
1028 if (gimple_code (x
) == GIMPLE_TRY
1029 && gimple_try_kind (x
) == GIMPLE_TRY_CATCH
1030 && gimple_try_catch_is_cleanup (x
))
1032 gsi_insert_seq_before (&gsi
, gimple_try_eval (x
), GSI_SAME_STMT
);
1033 gsi_remove (&gsi
, false);
1036 /* Wrap the block with protect_cleanup_actions as the action. */
1037 x
= gimple_build_eh_must_not_throw (protect_cleanup_actions
);
1038 x
= gimple_build_try (finally
, gimple_seq_alloc_with_stmt (x
),
1040 finally
= lower_eh_must_not_throw (outer_state
, x
);
1042 /* Drop all of this into the exception sequence. */
1043 emit_post_landing_pad (&eh_seq
, tf
->region
);
1044 gimple_seq_add_seq (&eh_seq
, finally
);
1045 if (finally_may_fallthru
)
1046 emit_resx (&eh_seq
, tf
->region
);
1048 /* Having now been handled, EH isn't to be considered with
1049 the rest of the outgoing edges. */
1050 tf
->may_throw
= false;
1053 /* A subroutine of lower_try_finally. We have determined that there is
1054 no fallthru edge out of the finally block. This means that there is
1055 no outgoing edge corresponding to any incoming edge. Restructure the
1056 try_finally node for this special case. */
1059 lower_try_finally_nofallthru (struct leh_state
*state
,
1060 struct leh_tf_state
*tf
)
1065 struct goto_queue_node
*q
, *qe
;
1067 lab
= create_artificial_label (gimple_location (tf
->try_finally_expr
));
1069 /* We expect that tf->top_p is a GIMPLE_TRY. */
1070 finally
= gimple_try_cleanup (tf
->top_p
);
1071 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1073 x
= gimple_build_label (lab
);
1074 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1077 qe
= q
+ tf
->goto_queue_active
;
1080 do_return_redirection (q
, lab
, NULL
);
1082 do_goto_redirection (q
, lab
, NULL
, tf
);
1084 replace_goto_queue (tf
);
1086 /* Emit the finally block into the stream. Lower EH_ELSE at this time. */
1087 eh_else
= get_eh_else (finally
);
1090 finally
= gimple_eh_else_n_body (eh_else
);
1091 lower_eh_constructs_1 (state
, &finally
);
1092 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1096 finally
= gimple_eh_else_e_body (eh_else
);
1097 lower_eh_constructs_1 (state
, &finally
);
1099 emit_post_landing_pad (&eh_seq
, tf
->region
);
1100 gimple_seq_add_seq (&eh_seq
, finally
);
1105 lower_eh_constructs_1 (state
, &finally
);
1106 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1110 emit_post_landing_pad (&eh_seq
, tf
->region
);
1112 x
= gimple_build_goto (lab
);
1113 gimple_set_location (x
, gimple_location (tf
->try_finally_expr
));
1114 gimple_seq_add_stmt (&eh_seq
, x
);
1119 /* A subroutine of lower_try_finally. We have determined that there is
1120 exactly one destination of the finally block. Restructure the
1121 try_finally node for this special case. */
1124 lower_try_finally_onedest (struct leh_state
*state
, struct leh_tf_state
*tf
)
1126 struct goto_queue_node
*q
, *qe
;
1129 gimple_stmt_iterator gsi
;
1131 location_t loc
= gimple_location (tf
->try_finally_expr
);
1133 finally
= gimple_try_cleanup (tf
->top_p
);
1134 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1136 /* Since there's only one destination, and the destination edge can only
1137 either be EH or non-EH, that implies that all of our incoming edges
1138 are of the same type. Therefore we can lower EH_ELSE immediately. */
1139 x
= get_eh_else (finally
);
1143 finally
= gimple_eh_else_e_body (x
);
1145 finally
= gimple_eh_else_n_body (x
);
1148 lower_eh_constructs_1 (state
, &finally
);
1150 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1152 gimple stmt
= gsi_stmt (gsi
);
1153 if (LOCATION_LOCUS (gimple_location (stmt
)) == UNKNOWN_LOCATION
)
1155 tree block
= gimple_block (stmt
);
1156 gimple_set_location (stmt
, gimple_location (tf
->try_finally_expr
));
1157 gimple_set_block (stmt
, block
);
1163 /* Only reachable via the exception edge. Add the given label to
1164 the head of the FINALLY block. Append a RESX at the end. */
1165 emit_post_landing_pad (&eh_seq
, tf
->region
);
1166 gimple_seq_add_seq (&eh_seq
, finally
);
1167 emit_resx (&eh_seq
, tf
->region
);
1171 if (tf
->may_fallthru
)
1173 /* Only reachable via the fallthru edge. Do nothing but let
1174 the two blocks run together; we'll fall out the bottom. */
1175 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1179 finally_label
= create_artificial_label (loc
);
1180 x
= gimple_build_label (finally_label
);
1181 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1183 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1186 qe
= q
+ tf
->goto_queue_active
;
1190 /* Reachable by return expressions only. Redirect them. */
1192 do_return_redirection (q
, finally_label
, NULL
);
1193 replace_goto_queue (tf
);
1197 /* Reachable by goto expressions only. Redirect them. */
1199 do_goto_redirection (q
, finally_label
, NULL
, tf
);
1200 replace_goto_queue (tf
);
1202 if (tf
->dest_array
[0] == tf
->fallthru_label
)
1204 /* Reachable by goto to fallthru label only. Redirect it
1205 to the new label (already created, sadly), and do not
1206 emit the final branch out, or the fallthru label. */
1207 tf
->fallthru_label
= NULL
;
1212 /* Place the original return/goto to the original destination
1213 immediately after the finally block. */
1214 x
= tf
->goto_queue
[0].cont_stmt
;
1215 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1216 maybe_record_in_goto_queue (state
, x
);
1219 /* A subroutine of lower_try_finally. There are multiple edges incoming
1220 and outgoing from the finally block. Implement this by duplicating the
1221 finally block for every destination. */
1224 lower_try_finally_copy (struct leh_state
*state
, struct leh_tf_state
*tf
)
1227 gimple_seq new_stmt
;
1231 location_t tf_loc
= gimple_location (tf
->try_finally_expr
);
1233 finally
= gimple_try_cleanup (tf
->top_p
);
1235 /* Notice EH_ELSE, and simplify some of the remaining code
1236 by considering FINALLY to be the normal return path only. */
1237 eh_else
= get_eh_else (finally
);
1239 finally
= gimple_eh_else_n_body (eh_else
);
1241 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1244 if (tf
->may_fallthru
)
1246 seq
= lower_try_finally_dup_block (finally
, state
, tf_loc
);
1247 lower_eh_constructs_1 (state
, &seq
);
1248 gimple_seq_add_seq (&new_stmt
, seq
);
1250 tmp
= lower_try_finally_fallthru_label (tf
);
1251 x
= gimple_build_goto (tmp
);
1252 gimple_set_location (x
, tf_loc
);
1253 gimple_seq_add_stmt (&new_stmt
, x
);
1258 /* We don't need to copy the EH path of EH_ELSE,
1259 since it is only emitted once. */
1261 seq
= gimple_eh_else_e_body (eh_else
);
1263 seq
= lower_try_finally_dup_block (finally
, state
, tf_loc
);
1264 lower_eh_constructs_1 (state
, &seq
);
1266 emit_post_landing_pad (&eh_seq
, tf
->region
);
1267 gimple_seq_add_seq (&eh_seq
, seq
);
1268 emit_resx (&eh_seq
, tf
->region
);
1273 struct goto_queue_node
*q
, *qe
;
1274 int return_index
, index
;
1277 struct goto_queue_node
*q
;
1281 return_index
= tf
->dest_array
.length ();
1282 labels
= XCNEWVEC (struct labels_s
, return_index
+ 1);
1285 qe
= q
+ tf
->goto_queue_active
;
1288 index
= q
->index
< 0 ? return_index
: q
->index
;
1290 if (!labels
[index
].q
)
1291 labels
[index
].q
= q
;
1294 for (index
= 0; index
< return_index
+ 1; index
++)
1298 q
= labels
[index
].q
;
1302 lab
= labels
[index
].label
1303 = create_artificial_label (tf_loc
);
1305 if (index
== return_index
)
1306 do_return_redirection (q
, lab
, NULL
);
1308 do_goto_redirection (q
, lab
, NULL
, tf
);
1310 x
= gimple_build_label (lab
);
1311 gimple_seq_add_stmt (&new_stmt
, x
);
1313 seq
= lower_try_finally_dup_block (finally
, state
, q
->location
);
1314 lower_eh_constructs_1 (state
, &seq
);
1315 gimple_seq_add_seq (&new_stmt
, seq
);
1317 gimple_seq_add_stmt (&new_stmt
, q
->cont_stmt
);
1318 maybe_record_in_goto_queue (state
, q
->cont_stmt
);
1321 for (q
= tf
->goto_queue
; q
< qe
; q
++)
1325 index
= q
->index
< 0 ? return_index
: q
->index
;
1327 if (labels
[index
].q
== q
)
1330 lab
= labels
[index
].label
;
1332 if (index
== return_index
)
1333 do_return_redirection (q
, lab
, NULL
);
1335 do_goto_redirection (q
, lab
, NULL
, tf
);
1338 replace_goto_queue (tf
);
1342 /* Need to link new stmts after running replace_goto_queue due
1343 to not wanting to process the same goto stmts twice. */
1344 gimple_seq_add_seq (&tf
->top_p_seq
, new_stmt
);
1347 /* A subroutine of lower_try_finally. There are multiple edges incoming
1348 and outgoing from the finally block. Implement this by instrumenting
1349 each incoming edge and creating a switch statement at the end of the
1350 finally block that branches to the appropriate destination. */
1353 lower_try_finally_switch (struct leh_state
*state
, struct leh_tf_state
*tf
)
1355 struct goto_queue_node
*q
, *qe
;
1356 tree finally_tmp
, finally_label
;
1357 int return_index
, eh_index
, fallthru_index
;
1358 int nlabels
, ndests
, j
, last_case_index
;
1360 vec
<tree
> case_label_vec
;
1361 gimple_seq switch_body
= NULL
;
1366 struct pointer_map_t
*cont_map
= NULL
;
1367 /* The location of the TRY_FINALLY stmt. */
1368 location_t tf_loc
= gimple_location (tf
->try_finally_expr
);
1369 /* The location of the finally block. */
1370 location_t finally_loc
;
1372 finally
= gimple_try_cleanup (tf
->top_p
);
1373 eh_else
= get_eh_else (finally
);
1375 /* Mash the TRY block to the head of the chain. */
1376 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1378 /* The location of the finally is either the last stmt in the finally
1379 block or the location of the TRY_FINALLY itself. */
1380 x
= gimple_seq_last_stmt (finally
);
1381 finally_loc
= x
? gimple_location (x
) : tf_loc
;
1383 /* Lower the finally block itself. */
1384 lower_eh_constructs_1 (state
, &finally
);
1386 /* Prepare for switch statement generation. */
1387 nlabels
= tf
->dest_array
.length ();
1388 return_index
= nlabels
;
1389 eh_index
= return_index
+ tf
->may_return
;
1390 fallthru_index
= eh_index
+ (tf
->may_throw
&& !eh_else
);
1391 ndests
= fallthru_index
+ tf
->may_fallthru
;
1393 finally_tmp
= create_tmp_var (integer_type_node
, "finally_tmp");
1394 finally_label
= create_artificial_label (finally_loc
);
1396 /* We use vec::quick_push on case_label_vec throughout this function,
1397 since we know the size in advance and allocate precisely as muce
1399 case_label_vec
.create (ndests
);
1401 last_case_index
= 0;
1403 /* Begin inserting code for getting to the finally block. Things
1404 are done in this order to correspond to the sequence the code is
1407 if (tf
->may_fallthru
)
1409 x
= gimple_build_assign (finally_tmp
,
1410 build_int_cst (integer_type_node
,
1412 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1414 tmp
= build_int_cst (integer_type_node
, fallthru_index
);
1415 last_case
= build_case_label (tmp
, NULL
,
1416 create_artificial_label (tf_loc
));
1417 case_label_vec
.quick_push (last_case
);
1420 x
= gimple_build_label (CASE_LABEL (last_case
));
1421 gimple_seq_add_stmt (&switch_body
, x
);
1423 tmp
= lower_try_finally_fallthru_label (tf
);
1424 x
= gimple_build_goto (tmp
);
1425 gimple_set_location (x
, tf_loc
);
1426 gimple_seq_add_stmt (&switch_body
, x
);
1429 /* For EH_ELSE, emit the exception path (plus resx) now, then
1430 subsequently we only need consider the normal path. */
1435 finally
= gimple_eh_else_e_body (eh_else
);
1436 lower_eh_constructs_1 (state
, &finally
);
1438 emit_post_landing_pad (&eh_seq
, tf
->region
);
1439 gimple_seq_add_seq (&eh_seq
, finally
);
1440 emit_resx (&eh_seq
, tf
->region
);
1443 finally
= gimple_eh_else_n_body (eh_else
);
1445 else if (tf
->may_throw
)
1447 emit_post_landing_pad (&eh_seq
, tf
->region
);
1449 x
= gimple_build_assign (finally_tmp
,
1450 build_int_cst (integer_type_node
, eh_index
));
1451 gimple_seq_add_stmt (&eh_seq
, x
);
1453 x
= gimple_build_goto (finally_label
);
1454 gimple_set_location (x
, tf_loc
);
1455 gimple_seq_add_stmt (&eh_seq
, x
);
1457 tmp
= build_int_cst (integer_type_node
, eh_index
);
1458 last_case
= build_case_label (tmp
, NULL
,
1459 create_artificial_label (tf_loc
));
1460 case_label_vec
.quick_push (last_case
);
1463 x
= gimple_build_label (CASE_LABEL (last_case
));
1464 gimple_seq_add_stmt (&eh_seq
, x
);
1465 emit_resx (&eh_seq
, tf
->region
);
1468 x
= gimple_build_label (finally_label
);
1469 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1471 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1473 /* Redirect each incoming goto edge. */
1475 qe
= q
+ tf
->goto_queue_active
;
1476 j
= last_case_index
+ tf
->may_return
;
1477 /* Prepare the assignments to finally_tmp that are executed upon the
1478 entrance through a particular edge. */
1481 gimple_seq mod
= NULL
;
1483 unsigned int case_index
;
1487 x
= gimple_build_assign (finally_tmp
,
1488 build_int_cst (integer_type_node
,
1490 gimple_seq_add_stmt (&mod
, x
);
1491 do_return_redirection (q
, finally_label
, mod
);
1492 switch_id
= return_index
;
1496 x
= gimple_build_assign (finally_tmp
,
1497 build_int_cst (integer_type_node
, q
->index
));
1498 gimple_seq_add_stmt (&mod
, x
);
1499 do_goto_redirection (q
, finally_label
, mod
, tf
);
1500 switch_id
= q
->index
;
1503 case_index
= j
+ q
->index
;
1504 if (case_label_vec
.length () <= case_index
|| !case_label_vec
[case_index
])
1508 tmp
= build_int_cst (integer_type_node
, switch_id
);
1509 case_lab
= build_case_label (tmp
, NULL
,
1510 create_artificial_label (tf_loc
));
1511 /* We store the cont_stmt in the pointer map, so that we can recover
1512 it in the loop below. */
1514 cont_map
= pointer_map_create ();
1515 slot
= pointer_map_insert (cont_map
, case_lab
);
1516 *slot
= q
->cont_stmt
;
1517 case_label_vec
.quick_push (case_lab
);
1520 for (j
= last_case_index
; j
< last_case_index
+ nlabels
; j
++)
1525 last_case
= case_label_vec
[j
];
1527 gcc_assert (last_case
);
1528 gcc_assert (cont_map
);
1530 slot
= pointer_map_contains (cont_map
, last_case
);
1532 cont_stmt
= *(gimple
*) slot
;
1534 x
= gimple_build_label (CASE_LABEL (last_case
));
1535 gimple_seq_add_stmt (&switch_body
, x
);
1536 gimple_seq_add_stmt (&switch_body
, cont_stmt
);
1537 maybe_record_in_goto_queue (state
, cont_stmt
);
1540 pointer_map_destroy (cont_map
);
1542 replace_goto_queue (tf
);
1544 /* Make sure that the last case is the default label, as one is required.
1545 Then sort the labels, which is also required in GIMPLE. */
1546 CASE_LOW (last_case
) = NULL
;
1547 sort_case_labels (case_label_vec
);
1549 /* Build the switch statement, setting last_case to be the default
1551 switch_stmt
= gimple_build_switch (finally_tmp
, last_case
,
1553 gimple_set_location (switch_stmt
, finally_loc
);
1555 /* Need to link SWITCH_STMT after running replace_goto_queue
1556 due to not wanting to process the same goto stmts twice. */
1557 gimple_seq_add_stmt (&tf
->top_p_seq
, switch_stmt
);
1558 gimple_seq_add_seq (&tf
->top_p_seq
, switch_body
);
1561 /* Decide whether or not we are going to duplicate the finally block.
1562 There are several considerations.
1564 First, if this is Java, then the finally block contains code
1565 written by the user. It has line numbers associated with it,
1566 so duplicating the block means it's difficult to set a breakpoint.
1567 Since controlling code generation via -g is verboten, we simply
1568 never duplicate code without optimization.
1570 Second, we'd like to prevent egregious code growth. One way to
1571 do this is to estimate the size of the finally block, multiply
1572 that by the number of copies we'd need to make, and compare against
1573 the estimate of the size of the switch machinery we'd have to add. */
1576 decide_copy_try_finally (int ndests
, bool may_throw
, gimple_seq finally
)
1578 int f_estimate
, sw_estimate
;
1581 /* If there's an EH_ELSE involved, the exception path is separate
1582 and really doesn't come into play for this computation. */
1583 eh_else
= get_eh_else (finally
);
1586 ndests
-= may_throw
;
1587 finally
= gimple_eh_else_n_body (eh_else
);
1592 gimple_stmt_iterator gsi
;
1597 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1599 gimple stmt
= gsi_stmt (gsi
);
1600 if (!is_gimple_debug (stmt
) && !gimple_clobber_p (stmt
))
1606 /* Finally estimate N times, plus N gotos. */
1607 f_estimate
= count_insns_seq (finally
, &eni_size_weights
);
1608 f_estimate
= (f_estimate
+ 1) * ndests
;
1610 /* Switch statement (cost 10), N variable assignments, N gotos. */
1611 sw_estimate
= 10 + 2 * ndests
;
1613 /* Optimize for size clearly wants our best guess. */
1614 if (optimize_function_for_size_p (cfun
))
1615 return f_estimate
< sw_estimate
;
1617 /* ??? These numbers are completely made up so far. */
1619 return f_estimate
< 100 || f_estimate
< sw_estimate
* 2;
1621 return f_estimate
< 40 || f_estimate
* 2 < sw_estimate
* 3;
1624 /* REG is the enclosing region for a possible cleanup region, or the region
1625 itself. Returns TRUE if such a region would be unreachable.
1627 Cleanup regions within a must-not-throw region aren't actually reachable
1628 even if there are throwing stmts within them, because the personality
1629 routine will call terminate before unwinding. */
1632 cleanup_is_dead_in (eh_region reg
)
1634 while (reg
&& reg
->type
== ERT_CLEANUP
)
1636 return (reg
&& reg
->type
== ERT_MUST_NOT_THROW
);
1639 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_FINALLY nodes
1640 to a sequence of labels and blocks, plus the exception region trees
1641 that record all the magic. This is complicated by the need to
1642 arrange for the FINALLY block to be executed on all exits. */
1645 lower_try_finally (struct leh_state
*state
, gimple tp
)
1647 struct leh_tf_state this_tf
;
1648 struct leh_state this_state
;
1650 gimple_seq old_eh_seq
;
1652 /* Process the try block. */
1654 memset (&this_tf
, 0, sizeof (this_tf
));
1655 this_tf
.try_finally_expr
= tp
;
1657 this_tf
.outer
= state
;
1658 if (using_eh_for_cleanups_p
&& !cleanup_is_dead_in (state
->cur_region
))
1660 this_tf
.region
= gen_eh_region_cleanup (state
->cur_region
);
1661 this_state
.cur_region
= this_tf
.region
;
1665 this_tf
.region
= NULL
;
1666 this_state
.cur_region
= state
->cur_region
;
1669 this_state
.ehp_region
= state
->ehp_region
;
1670 this_state
.tf
= &this_tf
;
1672 old_eh_seq
= eh_seq
;
1675 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1677 /* Determine if the try block is escaped through the bottom. */
1678 this_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1680 /* Determine if any exceptions are possible within the try block. */
1682 this_tf
.may_throw
= eh_region_may_contain_throw (this_tf
.region
);
1683 if (this_tf
.may_throw
)
1684 honor_protect_cleanup_actions (state
, &this_state
, &this_tf
);
1686 /* Determine how many edges (still) reach the finally block. Or rather,
1687 how many destinations are reached by the finally block. Use this to
1688 determine how we process the finally block itself. */
1690 ndests
= this_tf
.dest_array
.length ();
1691 ndests
+= this_tf
.may_fallthru
;
1692 ndests
+= this_tf
.may_return
;
1693 ndests
+= this_tf
.may_throw
;
1695 /* If the FINALLY block is not reachable, dike it out. */
1698 gimple_seq_add_seq (&this_tf
.top_p_seq
, gimple_try_eval (tp
));
1699 gimple_try_set_cleanup (tp
, NULL
);
1701 /* If the finally block doesn't fall through, then any destination
1702 we might try to impose there isn't reached either. There may be
1703 some minor amount of cleanup and redirection still needed. */
1704 else if (!gimple_seq_may_fallthru (gimple_try_cleanup (tp
)))
1705 lower_try_finally_nofallthru (state
, &this_tf
);
1707 /* We can easily special-case redirection to a single destination. */
1708 else if (ndests
== 1)
1709 lower_try_finally_onedest (state
, &this_tf
);
1710 else if (decide_copy_try_finally (ndests
, this_tf
.may_throw
,
1711 gimple_try_cleanup (tp
)))
1712 lower_try_finally_copy (state
, &this_tf
);
1714 lower_try_finally_switch (state
, &this_tf
);
1716 /* If someone requested we add a label at the end of the transformed
1718 if (this_tf
.fallthru_label
)
1720 /* This must be reached only if ndests == 0. */
1721 gimple x
= gimple_build_label (this_tf
.fallthru_label
);
1722 gimple_seq_add_stmt (&this_tf
.top_p_seq
, x
);
1725 this_tf
.dest_array
.release ();
1726 free (this_tf
.goto_queue
);
1727 if (this_tf
.goto_queue_map
)
1728 pointer_map_destroy (this_tf
.goto_queue_map
);
1730 /* If there was an old (aka outer) eh_seq, append the current eh_seq.
1731 If there was no old eh_seq, then the append is trivially already done. */
1735 eh_seq
= old_eh_seq
;
1738 gimple_seq new_eh_seq
= eh_seq
;
1739 eh_seq
= old_eh_seq
;
1740 gimple_seq_add_seq (&eh_seq
, new_eh_seq
);
1744 return this_tf
.top_p_seq
;
1747 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_CATCH with a
1748 list of GIMPLE_CATCH to a sequence of labels and blocks, plus the
1749 exception region trees that records all the magic. */
1752 lower_catch (struct leh_state
*state
, gimple tp
)
1754 eh_region try_region
= NULL
;
1755 struct leh_state this_state
= *state
;
1756 gimple_stmt_iterator gsi
;
1758 gimple_seq new_seq
, cleanup
;
1760 location_t try_catch_loc
= gimple_location (tp
);
1762 if (flag_exceptions
)
1764 try_region
= gen_eh_region_try (state
->cur_region
);
1765 this_state
.cur_region
= try_region
;
1768 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1770 if (!eh_region_may_contain_throw (try_region
))
1771 return gimple_try_eval (tp
);
1774 emit_eh_dispatch (&new_seq
, try_region
);
1775 emit_resx (&new_seq
, try_region
);
1777 this_state
.cur_region
= state
->cur_region
;
1778 this_state
.ehp_region
= try_region
;
1781 cleanup
= gimple_try_cleanup (tp
);
1782 for (gsi
= gsi_start (cleanup
);
1790 gcatch
= gsi_stmt (gsi
);
1791 c
= gen_eh_region_catch (try_region
, gimple_catch_types (gcatch
));
1793 handler
= gimple_catch_handler (gcatch
);
1794 lower_eh_constructs_1 (&this_state
, &handler
);
1796 c
->label
= create_artificial_label (UNKNOWN_LOCATION
);
1797 x
= gimple_build_label (c
->label
);
1798 gimple_seq_add_stmt (&new_seq
, x
);
1800 gimple_seq_add_seq (&new_seq
, handler
);
1802 if (gimple_seq_may_fallthru (new_seq
))
1805 out_label
= create_artificial_label (try_catch_loc
);
1807 x
= gimple_build_goto (out_label
);
1808 gimple_seq_add_stmt (&new_seq
, x
);
1814 gimple_try_set_cleanup (tp
, new_seq
);
1816 return frob_into_branch_around (tp
, try_region
, out_label
);
1819 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with a
1820 GIMPLE_EH_FILTER to a sequence of labels and blocks, plus the exception
1821 region trees that record all the magic. */
1824 lower_eh_filter (struct leh_state
*state
, gimple tp
)
1826 struct leh_state this_state
= *state
;
1827 eh_region this_region
= NULL
;
1831 inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1833 if (flag_exceptions
)
1835 this_region
= gen_eh_region_allowed (state
->cur_region
,
1836 gimple_eh_filter_types (inner
));
1837 this_state
.cur_region
= this_region
;
1840 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1842 if (!eh_region_may_contain_throw (this_region
))
1843 return gimple_try_eval (tp
);
1846 this_state
.cur_region
= state
->cur_region
;
1847 this_state
.ehp_region
= this_region
;
1849 emit_eh_dispatch (&new_seq
, this_region
);
1850 emit_resx (&new_seq
, this_region
);
1852 this_region
->u
.allowed
.label
= create_artificial_label (UNKNOWN_LOCATION
);
1853 x
= gimple_build_label (this_region
->u
.allowed
.label
);
1854 gimple_seq_add_stmt (&new_seq
, x
);
1856 lower_eh_constructs_1 (&this_state
, gimple_eh_filter_failure_ptr (inner
));
1857 gimple_seq_add_seq (&new_seq
, gimple_eh_filter_failure (inner
));
1859 gimple_try_set_cleanup (tp
, new_seq
);
1861 return frob_into_branch_around (tp
, this_region
, NULL
);
1864 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with
1865 an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks,
1866 plus the exception region trees that record all the magic. */
1869 lower_eh_must_not_throw (struct leh_state
*state
, gimple tp
)
1871 struct leh_state this_state
= *state
;
1873 if (flag_exceptions
)
1875 gimple inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1876 eh_region this_region
;
1878 this_region
= gen_eh_region_must_not_throw (state
->cur_region
);
1879 this_region
->u
.must_not_throw
.failure_decl
1880 = gimple_eh_must_not_throw_fndecl (inner
);
1881 this_region
->u
.must_not_throw
.failure_loc
1882 = LOCATION_LOCUS (gimple_location (tp
));
1884 /* In order to get mangling applied to this decl, we must mark it
1885 used now. Otherwise, pass_ipa_free_lang_data won't think it
1887 TREE_USED (this_region
->u
.must_not_throw
.failure_decl
) = 1;
1889 this_state
.cur_region
= this_region
;
1892 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1894 return gimple_try_eval (tp
);
1897 /* Implement a cleanup expression. This is similar to try-finally,
1898 except that we only execute the cleanup block for exception edges. */
1901 lower_cleanup (struct leh_state
*state
, gimple tp
)
1903 struct leh_state this_state
= *state
;
1904 eh_region this_region
= NULL
;
1905 struct leh_tf_state fake_tf
;
1907 bool cleanup_dead
= cleanup_is_dead_in (state
->cur_region
);
1909 if (flag_exceptions
&& !cleanup_dead
)
1911 this_region
= gen_eh_region_cleanup (state
->cur_region
);
1912 this_state
.cur_region
= this_region
;
1915 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1917 if (cleanup_dead
|| !eh_region_may_contain_throw (this_region
))
1918 return gimple_try_eval (tp
);
1920 /* Build enough of a try-finally state so that we can reuse
1921 honor_protect_cleanup_actions. */
1922 memset (&fake_tf
, 0, sizeof (fake_tf
));
1923 fake_tf
.top_p
= fake_tf
.try_finally_expr
= tp
;
1924 fake_tf
.outer
= state
;
1925 fake_tf
.region
= this_region
;
1926 fake_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1927 fake_tf
.may_throw
= true;
1929 honor_protect_cleanup_actions (state
, NULL
, &fake_tf
);
1931 if (fake_tf
.may_throw
)
1933 /* In this case honor_protect_cleanup_actions had nothing to do,
1934 and we should process this normally. */
1935 lower_eh_constructs_1 (state
, gimple_try_cleanup_ptr (tp
));
1936 result
= frob_into_branch_around (tp
, this_region
,
1937 fake_tf
.fallthru_label
);
1941 /* In this case honor_protect_cleanup_actions did nearly all of
1942 the work. All we have left is to append the fallthru_label. */
1944 result
= gimple_try_eval (tp
);
1945 if (fake_tf
.fallthru_label
)
1947 gimple x
= gimple_build_label (fake_tf
.fallthru_label
);
1948 gimple_seq_add_stmt (&result
, x
);
1954 /* Main loop for lowering eh constructs. Also moves gsi to the next
1958 lower_eh_constructs_2 (struct leh_state
*state
, gimple_stmt_iterator
*gsi
)
1962 gimple stmt
= gsi_stmt (*gsi
);
1964 switch (gimple_code (stmt
))
1968 tree fndecl
= gimple_call_fndecl (stmt
);
1971 if (fndecl
&& DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
1972 switch (DECL_FUNCTION_CODE (fndecl
))
1974 case BUILT_IN_EH_POINTER
:
1975 /* The front end may have generated a call to
1976 __builtin_eh_pointer (0) within a catch region. Replace
1977 this zero argument with the current catch region number. */
1978 if (state
->ehp_region
)
1980 tree nr
= build_int_cst (integer_type_node
,
1981 state
->ehp_region
->index
);
1982 gimple_call_set_arg (stmt
, 0, nr
);
1986 /* The user has dome something silly. Remove it. */
1987 rhs
= null_pointer_node
;
1992 case BUILT_IN_EH_FILTER
:
1993 /* ??? This should never appear, but since it's a builtin it
1994 is accessible to abuse by users. Just remove it and
1995 replace the use with the arbitrary value zero. */
1996 rhs
= build_int_cst (TREE_TYPE (TREE_TYPE (fndecl
)), 0);
1998 lhs
= gimple_call_lhs (stmt
);
1999 x
= gimple_build_assign (lhs
, rhs
);
2000 gsi_insert_before (gsi
, x
, GSI_SAME_STMT
);
2003 case BUILT_IN_EH_COPY_VALUES
:
2004 /* Likewise this should not appear. Remove it. */
2005 gsi_remove (gsi
, true);
2015 /* If the stmt can throw use a new temporary for the assignment
2016 to a LHS. This makes sure the old value of the LHS is
2017 available on the EH edge. Only do so for statements that
2018 potentially fall through (no noreturn calls e.g.), otherwise
2019 this new assignment might create fake fallthru regions. */
2020 if (stmt_could_throw_p (stmt
)
2021 && gimple_has_lhs (stmt
)
2022 && gimple_stmt_may_fallthru (stmt
)
2023 && !tree_could_throw_p (gimple_get_lhs (stmt
))
2024 && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt
))))
2026 tree lhs
= gimple_get_lhs (stmt
);
2027 tree tmp
= create_tmp_var (TREE_TYPE (lhs
), NULL
);
2028 gimple s
= gimple_build_assign (lhs
, tmp
);
2029 gimple_set_location (s
, gimple_location (stmt
));
2030 gimple_set_block (s
, gimple_block (stmt
));
2031 gimple_set_lhs (stmt
, tmp
);
2032 if (TREE_CODE (TREE_TYPE (tmp
)) == COMPLEX_TYPE
2033 || TREE_CODE (TREE_TYPE (tmp
)) == VECTOR_TYPE
)
2034 DECL_GIMPLE_REG_P (tmp
) = 1;
2035 gsi_insert_after (gsi
, s
, GSI_SAME_STMT
);
2037 /* Look for things that can throw exceptions, and record them. */
2038 if (state
->cur_region
&& stmt_could_throw_p (stmt
))
2040 record_stmt_eh_region (state
->cur_region
, stmt
);
2041 note_eh_region_may_contain_throw (state
->cur_region
);
2048 maybe_record_in_goto_queue (state
, stmt
);
2052 verify_norecord_switch_expr (state
, stmt
);
2056 if (gimple_try_kind (stmt
) == GIMPLE_TRY_FINALLY
)
2057 replace
= lower_try_finally (state
, stmt
);
2060 x
= gimple_seq_first_stmt (gimple_try_cleanup (stmt
));
2063 replace
= gimple_try_eval (stmt
);
2064 lower_eh_constructs_1 (state
, &replace
);
2067 switch (gimple_code (x
))
2070 replace
= lower_catch (state
, stmt
);
2072 case GIMPLE_EH_FILTER
:
2073 replace
= lower_eh_filter (state
, stmt
);
2075 case GIMPLE_EH_MUST_NOT_THROW
:
2076 replace
= lower_eh_must_not_throw (state
, stmt
);
2078 case GIMPLE_EH_ELSE
:
2079 /* This code is only valid with GIMPLE_TRY_FINALLY. */
2082 replace
= lower_cleanup (state
, stmt
);
2087 /* Remove the old stmt and insert the transformed sequence
2089 gsi_insert_seq_before (gsi
, replace
, GSI_SAME_STMT
);
2090 gsi_remove (gsi
, true);
2092 /* Return since we don't want gsi_next () */
2095 case GIMPLE_EH_ELSE
:
2096 /* We should be eliminating this in lower_try_finally et al. */
2100 /* A type, a decl, or some kind of statement that we're not
2101 interested in. Don't walk them. */
2108 /* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */
2111 lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*pseq
)
2113 gimple_stmt_iterator gsi
;
2114 for (gsi
= gsi_start (*pseq
); !gsi_end_p (gsi
);)
2115 lower_eh_constructs_2 (state
, &gsi
);
2119 lower_eh_constructs (void)
2121 struct leh_state null_state
;
2124 bodyp
= gimple_body (current_function_decl
);
2128 finally_tree
.create (31);
2129 eh_region_may_contain_throw_map
= BITMAP_ALLOC (NULL
);
2130 memset (&null_state
, 0, sizeof (null_state
));
2132 collect_finally_tree_1 (bodyp
, NULL
);
2133 lower_eh_constructs_1 (&null_state
, &bodyp
);
2134 gimple_set_body (current_function_decl
, bodyp
);
2136 /* We assume there's a return statement, or something, at the end of
2137 the function, and thus ploping the EH sequence afterward won't
2139 gcc_assert (!gimple_seq_may_fallthru (bodyp
));
2140 gimple_seq_add_seq (&bodyp
, eh_seq
);
2142 /* We assume that since BODYP already existed, adding EH_SEQ to it
2143 didn't change its value, and we don't have to re-set the function. */
2144 gcc_assert (bodyp
== gimple_body (current_function_decl
));
2146 finally_tree
.dispose ();
2147 BITMAP_FREE (eh_region_may_contain_throw_map
);
2150 /* If this function needs a language specific EH personality routine
2151 and the frontend didn't already set one do so now. */
2152 if (function_needs_eh_personality (cfun
) == eh_personality_lang
2153 && !DECL_FUNCTION_PERSONALITY (current_function_decl
))
2154 DECL_FUNCTION_PERSONALITY (current_function_decl
)
2155 = lang_hooks
.eh_personality ();
2162 const pass_data pass_data_lower_eh
=
2164 GIMPLE_PASS
, /* type */
2166 OPTGROUP_NONE
, /* optinfo_flags */
2167 false, /* has_gate */
2168 true, /* has_execute */
2169 TV_TREE_EH
, /* tv_id */
2170 PROP_gimple_lcf
, /* properties_required */
2171 PROP_gimple_leh
, /* properties_provided */
2172 0, /* properties_destroyed */
2173 0, /* todo_flags_start */
2174 0, /* todo_flags_finish */
2177 class pass_lower_eh
: public gimple_opt_pass
2180 pass_lower_eh (gcc::context
*ctxt
)
2181 : gimple_opt_pass (pass_data_lower_eh
, ctxt
)
2184 /* opt_pass methods: */
2185 unsigned int execute () { return lower_eh_constructs (); }
2187 }; // class pass_lower_eh
2192 make_pass_lower_eh (gcc::context
*ctxt
)
2194 return new pass_lower_eh (ctxt
);
2197 /* Create the multiple edges from an EH_DISPATCH statement to all of
2198 the possible handlers for its EH region. Return true if there's
2199 no fallthru edge; false if there is. */
2202 make_eh_dispatch_edges (gimple stmt
)
2206 basic_block src
, dst
;
2208 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2209 src
= gimple_bb (stmt
);
2214 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2216 dst
= label_to_block (c
->label
);
2217 make_edge (src
, dst
, 0);
2219 /* A catch-all handler doesn't have a fallthru. */
2220 if (c
->type_list
== NULL
)
2225 case ERT_ALLOWED_EXCEPTIONS
:
2226 dst
= label_to_block (r
->u
.allowed
.label
);
2227 make_edge (src
, dst
, 0);
2237 /* Create the single EH edge from STMT to its nearest landing pad,
2238 if there is such a landing pad within the current function. */
2241 make_eh_edges (gimple stmt
)
2243 basic_block src
, dst
;
2247 lp_nr
= lookup_stmt_eh_lp (stmt
);
2251 lp
= get_eh_landing_pad_from_number (lp_nr
);
2252 gcc_assert (lp
!= NULL
);
2254 src
= gimple_bb (stmt
);
2255 dst
= label_to_block (lp
->post_landing_pad
);
2256 make_edge (src
, dst
, EDGE_EH
);
2259 /* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
2260 do not actually perform the final edge redirection.
2262 CHANGE_REGION is true when we're being called from cleanup_empty_eh and
2263 we intend to change the destination EH region as well; this means
2264 EH_LANDING_PAD_NR must already be set on the destination block label.
2265 If false, we're being called from generic cfg manipulation code and we
2266 should preserve our place within the region tree. */
2269 redirect_eh_edge_1 (edge edge_in
, basic_block new_bb
, bool change_region
)
2271 eh_landing_pad old_lp
, new_lp
;
2274 int old_lp_nr
, new_lp_nr
;
2275 tree old_label
, new_label
;
2279 old_bb
= edge_in
->dest
;
2280 old_label
= gimple_block_label (old_bb
);
2281 old_lp_nr
= EH_LANDING_PAD_NR (old_label
);
2282 gcc_assert (old_lp_nr
> 0);
2283 old_lp
= get_eh_landing_pad_from_number (old_lp_nr
);
2285 throw_stmt
= last_stmt (edge_in
->src
);
2286 gcc_assert (lookup_stmt_eh_lp (throw_stmt
) == old_lp_nr
);
2288 new_label
= gimple_block_label (new_bb
);
2290 /* Look for an existing region that might be using NEW_BB already. */
2291 new_lp_nr
= EH_LANDING_PAD_NR (new_label
);
2294 new_lp
= get_eh_landing_pad_from_number (new_lp_nr
);
2295 gcc_assert (new_lp
);
2297 /* Unless CHANGE_REGION is true, the new and old landing pad
2298 had better be associated with the same EH region. */
2299 gcc_assert (change_region
|| new_lp
->region
== old_lp
->region
);
2304 gcc_assert (!change_region
);
2307 /* Notice when we redirect the last EH edge away from OLD_BB. */
2308 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
2309 if (e
!= edge_in
&& (e
->flags
& EDGE_EH
))
2314 /* NEW_LP already exists. If there are still edges into OLD_LP,
2315 there's nothing to do with the EH tree. If there are no more
2316 edges into OLD_LP, then we want to remove OLD_LP as it is unused.
2317 If CHANGE_REGION is true, then our caller is expecting to remove
2319 if (e
== NULL
&& !change_region
)
2320 remove_eh_landing_pad (old_lp
);
2324 /* No correct landing pad exists. If there are no more edges
2325 into OLD_LP, then we can simply re-use the existing landing pad.
2326 Otherwise, we have to create a new landing pad. */
2329 EH_LANDING_PAD_NR (old_lp
->post_landing_pad
) = 0;
2333 new_lp
= gen_eh_landing_pad (old_lp
->region
);
2334 new_lp
->post_landing_pad
= new_label
;
2335 EH_LANDING_PAD_NR (new_label
) = new_lp
->index
;
2338 /* Maybe move the throwing statement to the new region. */
2339 if (old_lp
!= new_lp
)
2341 remove_stmt_from_eh_lp (throw_stmt
);
2342 add_stmt_to_eh_lp (throw_stmt
, new_lp
->index
);
2346 /* Redirect EH edge E to NEW_BB. */
2349 redirect_eh_edge (edge edge_in
, basic_block new_bb
)
2351 redirect_eh_edge_1 (edge_in
, new_bb
, false);
2352 return ssa_redirect_edge (edge_in
, new_bb
);
2355 /* This is a subroutine of gimple_redirect_edge_and_branch. Update the
2356 labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
2357 The actual edge update will happen in the caller. */
2360 redirect_eh_dispatch_edge (gimple stmt
, edge e
, basic_block new_bb
)
2362 tree new_lab
= gimple_block_label (new_bb
);
2363 bool any_changed
= false;
2368 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2372 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2374 old_bb
= label_to_block (c
->label
);
2375 if (old_bb
== e
->dest
)
2383 case ERT_ALLOWED_EXCEPTIONS
:
2384 old_bb
= label_to_block (r
->u
.allowed
.label
);
2385 gcc_assert (old_bb
== e
->dest
);
2386 r
->u
.allowed
.label
= new_lab
;
2394 gcc_assert (any_changed
);
2397 /* Helper function for operation_could_trap_p and stmt_could_throw_p. */
2400 operation_could_trap_helper_p (enum tree_code op
,
2411 case TRUNC_DIV_EXPR
:
2413 case FLOOR_DIV_EXPR
:
2414 case ROUND_DIV_EXPR
:
2415 case EXACT_DIV_EXPR
:
2417 case FLOOR_MOD_EXPR
:
2418 case ROUND_MOD_EXPR
:
2419 case TRUNC_MOD_EXPR
:
2421 if (honor_snans
|| honor_trapv
)
2424 return flag_trapping_math
;
2425 if (!TREE_CONSTANT (divisor
) || integer_zerop (divisor
))
2434 /* Some floating point comparisons may trap. */
2439 case UNORDERED_EXPR
:
2449 case FIX_TRUNC_EXPR
:
2450 /* Conversion of floating point might trap. */
2456 /* These operations don't trap with floating point. */
2464 /* Any floating arithmetic may trap. */
2465 if (fp_operation
&& flag_trapping_math
)
2473 /* Constructing an object cannot trap. */
2477 /* Any floating arithmetic may trap. */
2478 if (fp_operation
&& flag_trapping_math
)
2486 /* Return true if operation OP may trap. FP_OPERATION is true if OP is applied
2487 on floating-point values. HONOR_TRAPV is true if OP is applied on integer
2488 type operands that may trap. If OP is a division operator, DIVISOR contains
2489 the value of the divisor. */
2492 operation_could_trap_p (enum tree_code op
, bool fp_operation
, bool honor_trapv
,
2495 bool honor_nans
= (fp_operation
&& flag_trapping_math
2496 && !flag_finite_math_only
);
2497 bool honor_snans
= fp_operation
&& flag_signaling_nans
!= 0;
2500 if (TREE_CODE_CLASS (op
) != tcc_comparison
2501 && TREE_CODE_CLASS (op
) != tcc_unary
2502 && TREE_CODE_CLASS (op
) != tcc_binary
)
2505 return operation_could_trap_helper_p (op
, fp_operation
, honor_trapv
,
2506 honor_nans
, honor_snans
, divisor
,
2510 /* Return true if EXPR can trap, as in dereferencing an invalid pointer
2511 location or floating point arithmetic. C.f. the rtl version, may_trap_p.
2512 This routine expects only GIMPLE lhs or rhs input. */
2515 tree_could_trap_p (tree expr
)
2517 enum tree_code code
;
2518 bool fp_operation
= false;
2519 bool honor_trapv
= false;
2520 tree t
, base
, div
= NULL_TREE
;
2525 code
= TREE_CODE (expr
);
2526 t
= TREE_TYPE (expr
);
2530 if (COMPARISON_CLASS_P (expr
))
2531 fp_operation
= FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 0)));
2533 fp_operation
= FLOAT_TYPE_P (t
);
2534 honor_trapv
= INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
);
2537 if (TREE_CODE_CLASS (code
) == tcc_binary
)
2538 div
= TREE_OPERAND (expr
, 1);
2539 if (operation_could_trap_p (code
, fp_operation
, honor_trapv
, div
))
2545 case TARGET_MEM_REF
:
2546 if (TREE_CODE (TMR_BASE (expr
)) == ADDR_EXPR
2547 && !TMR_INDEX (expr
) && !TMR_INDEX2 (expr
))
2549 return !TREE_THIS_NOTRAP (expr
);
2555 case VIEW_CONVERT_EXPR
:
2556 case WITH_SIZE_EXPR
:
2557 expr
= TREE_OPERAND (expr
, 0);
2558 code
= TREE_CODE (expr
);
2561 case ARRAY_RANGE_REF
:
2562 base
= TREE_OPERAND (expr
, 0);
2563 if (tree_could_trap_p (base
))
2565 if (TREE_THIS_NOTRAP (expr
))
2567 return !range_in_array_bounds_p (expr
);
2570 base
= TREE_OPERAND (expr
, 0);
2571 if (tree_could_trap_p (base
))
2573 if (TREE_THIS_NOTRAP (expr
))
2575 return !in_array_bounds_p (expr
);
2578 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
)
2582 return !TREE_THIS_NOTRAP (expr
);
2585 return TREE_THIS_VOLATILE (expr
);
2588 t
= get_callee_fndecl (expr
);
2589 /* Assume that calls to weak functions may trap. */
2590 if (!t
|| !DECL_P (t
))
2593 return tree_could_trap_p (t
);
2597 /* Assume that accesses to weak functions may trap, unless we know
2598 they are certainly defined in current TU or in some other
2600 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
))
2602 struct cgraph_node
*node
;
2603 if (!DECL_EXTERNAL (expr
))
2605 node
= cgraph_function_node (cgraph_get_node (expr
), NULL
);
2606 if (node
&& node
->symbol
.in_other_partition
)
2613 /* Assume that accesses to weak vars may trap, unless we know
2614 they are certainly defined in current TU or in some other
2616 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
))
2618 struct varpool_node
*node
;
2619 if (!DECL_EXTERNAL (expr
))
2621 node
= varpool_variable_node (varpool_get_node (expr
), NULL
);
2622 if (node
&& node
->symbol
.in_other_partition
)
2634 /* Helper for stmt_could_throw_p. Return true if STMT (assumed to be a
2635 an assignment or a conditional) may throw. */
2638 stmt_could_throw_1_p (gimple stmt
)
2640 enum tree_code code
= gimple_expr_code (stmt
);
2641 bool honor_nans
= false;
2642 bool honor_snans
= false;
2643 bool fp_operation
= false;
2644 bool honor_trapv
= false;
2649 if (TREE_CODE_CLASS (code
) == tcc_comparison
2650 || TREE_CODE_CLASS (code
) == tcc_unary
2651 || TREE_CODE_CLASS (code
) == tcc_binary
)
2653 if (is_gimple_assign (stmt
)
2654 && TREE_CODE_CLASS (code
) == tcc_comparison
)
2655 t
= TREE_TYPE (gimple_assign_rhs1 (stmt
));
2656 else if (gimple_code (stmt
) == GIMPLE_COND
)
2657 t
= TREE_TYPE (gimple_cond_lhs (stmt
));
2659 t
= gimple_expr_type (stmt
);
2660 fp_operation
= FLOAT_TYPE_P (t
);
2663 honor_nans
= flag_trapping_math
&& !flag_finite_math_only
;
2664 honor_snans
= flag_signaling_nans
!= 0;
2666 else if (INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
))
2670 /* Check if the main expression may trap. */
2671 t
= is_gimple_assign (stmt
) ? gimple_assign_rhs2 (stmt
) : NULL
;
2672 ret
= operation_could_trap_helper_p (code
, fp_operation
, honor_trapv
,
2673 honor_nans
, honor_snans
, t
,
2678 /* If the expression does not trap, see if any of the individual operands may
2680 for (i
= 0; i
< gimple_num_ops (stmt
); i
++)
2681 if (tree_could_trap_p (gimple_op (stmt
, i
)))
2688 /* Return true if statement STMT could throw an exception. */
2691 stmt_could_throw_p (gimple stmt
)
2693 if (!flag_exceptions
)
2696 /* The only statements that can throw an exception are assignments,
2697 conditionals, calls, resx, and asms. */
2698 switch (gimple_code (stmt
))
2704 return !gimple_call_nothrow_p (stmt
);
2708 if (!cfun
->can_throw_non_call_exceptions
)
2710 return stmt_could_throw_1_p (stmt
);
2713 if (!cfun
->can_throw_non_call_exceptions
)
2715 return gimple_asm_volatile_p (stmt
);
2723 /* Return true if expression T could throw an exception. */
2726 tree_could_throw_p (tree t
)
2728 if (!flag_exceptions
)
2730 if (TREE_CODE (t
) == MODIFY_EXPR
)
2732 if (cfun
->can_throw_non_call_exceptions
2733 && tree_could_trap_p (TREE_OPERAND (t
, 0)))
2735 t
= TREE_OPERAND (t
, 1);
2738 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
2739 t
= TREE_OPERAND (t
, 0);
2740 if (TREE_CODE (t
) == CALL_EXPR
)
2741 return (call_expr_flags (t
) & ECF_NOTHROW
) == 0;
2742 if (cfun
->can_throw_non_call_exceptions
)
2743 return tree_could_trap_p (t
);
2747 /* Return true if STMT can throw an exception that is not caught within
2748 the current function (CFUN). */
2751 stmt_can_throw_external (gimple stmt
)
2755 if (!stmt_could_throw_p (stmt
))
2758 lp_nr
= lookup_stmt_eh_lp (stmt
);
2762 /* Return true if STMT can throw an exception that is caught within
2763 the current function (CFUN). */
2766 stmt_can_throw_internal (gimple stmt
)
2770 if (!stmt_could_throw_p (stmt
))
2773 lp_nr
= lookup_stmt_eh_lp (stmt
);
2777 /* Given a statement STMT in IFUN, if STMT can no longer throw, then
2778 remove any entry it might have from the EH table. Return true if
2779 any change was made. */
2782 maybe_clean_eh_stmt_fn (struct function
*ifun
, gimple stmt
)
2784 if (stmt_could_throw_p (stmt
))
2786 return remove_stmt_from_eh_lp_fn (ifun
, stmt
);
2789 /* Likewise, but always use the current function. */
2792 maybe_clean_eh_stmt (gimple stmt
)
2794 return maybe_clean_eh_stmt_fn (cfun
, stmt
);
2797 /* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
2798 OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
2799 in the table if it should be in there. Return TRUE if a replacement was
2800 done that my require an EH edge purge. */
2803 maybe_clean_or_replace_eh_stmt (gimple old_stmt
, gimple new_stmt
)
2805 int lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2809 bool new_stmt_could_throw
= stmt_could_throw_p (new_stmt
);
2811 if (new_stmt
== old_stmt
&& new_stmt_could_throw
)
2814 remove_stmt_from_eh_lp (old_stmt
);
2815 if (new_stmt_could_throw
)
2817 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
2827 /* Given a statement OLD_STMT in OLD_FUN and a duplicate statement NEW_STMT
2828 in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT. The MAP
2829 operand is the return value of duplicate_eh_regions. */
2832 maybe_duplicate_eh_stmt_fn (struct function
*new_fun
, gimple new_stmt
,
2833 struct function
*old_fun
, gimple old_stmt
,
2834 struct pointer_map_t
*map
, int default_lp_nr
)
2836 int old_lp_nr
, new_lp_nr
;
2839 if (!stmt_could_throw_p (new_stmt
))
2842 old_lp_nr
= lookup_stmt_eh_lp_fn (old_fun
, old_stmt
);
2845 if (default_lp_nr
== 0)
2847 new_lp_nr
= default_lp_nr
;
2849 else if (old_lp_nr
> 0)
2851 eh_landing_pad old_lp
, new_lp
;
2853 old_lp
= (*old_fun
->eh
->lp_array
)[old_lp_nr
];
2854 slot
= pointer_map_contains (map
, old_lp
);
2855 new_lp
= (eh_landing_pad
) *slot
;
2856 new_lp_nr
= new_lp
->index
;
2860 eh_region old_r
, new_r
;
2862 old_r
= (*old_fun
->eh
->region_array
)[-old_lp_nr
];
2863 slot
= pointer_map_contains (map
, old_r
);
2864 new_r
= (eh_region
) *slot
;
2865 new_lp_nr
= -new_r
->index
;
2868 add_stmt_to_eh_lp_fn (new_fun
, new_stmt
, new_lp_nr
);
2872 /* Similar, but both OLD_STMT and NEW_STMT are within the current function,
2873 and thus no remapping is required. */
2876 maybe_duplicate_eh_stmt (gimple new_stmt
, gimple old_stmt
)
2880 if (!stmt_could_throw_p (new_stmt
))
2883 lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2887 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
2891 /* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of
2892 GIMPLE_TRY) that are similar enough to be considered the same. Currently
2893 this only handles handlers consisting of a single call, as that's the
2894 important case for C++: a destructor call for a particular object showing
2895 up in multiple handlers. */
2898 same_handler_p (gimple_seq oneh
, gimple_seq twoh
)
2900 gimple_stmt_iterator gsi
;
2904 gsi
= gsi_start (oneh
);
2905 if (!gsi_one_before_end_p (gsi
))
2907 ones
= gsi_stmt (gsi
);
2909 gsi
= gsi_start (twoh
);
2910 if (!gsi_one_before_end_p (gsi
))
2912 twos
= gsi_stmt (gsi
);
2914 if (!is_gimple_call (ones
)
2915 || !is_gimple_call (twos
)
2916 || gimple_call_lhs (ones
)
2917 || gimple_call_lhs (twos
)
2918 || gimple_call_chain (ones
)
2919 || gimple_call_chain (twos
)
2920 || !gimple_call_same_target_p (ones
, twos
)
2921 || gimple_call_num_args (ones
) != gimple_call_num_args (twos
))
2924 for (ai
= 0; ai
< gimple_call_num_args (ones
); ++ai
)
2925 if (!operand_equal_p (gimple_call_arg (ones
, ai
),
2926 gimple_call_arg (twos
, ai
), 0))
2933 try { A() } finally { try { ~B() } catch { ~A() } }
2934 try { ... } finally { ~A() }
2936 try { A() } catch { ~B() }
2937 try { ~B() ... } finally { ~A() }
2939 This occurs frequently in C++, where A is a local variable and B is a
2940 temporary used in the initializer for A. */
2943 optimize_double_finally (gimple one
, gimple two
)
2946 gimple_stmt_iterator gsi
;
2949 cleanup
= gimple_try_cleanup (one
);
2950 gsi
= gsi_start (cleanup
);
2951 if (!gsi_one_before_end_p (gsi
))
2954 oneh
= gsi_stmt (gsi
);
2955 if (gimple_code (oneh
) != GIMPLE_TRY
2956 || gimple_try_kind (oneh
) != GIMPLE_TRY_CATCH
)
2959 if (same_handler_p (gimple_try_cleanup (oneh
), gimple_try_cleanup (two
)))
2961 gimple_seq seq
= gimple_try_eval (oneh
);
2963 gimple_try_set_cleanup (one
, seq
);
2964 gimple_try_set_kind (one
, GIMPLE_TRY_CATCH
);
2965 seq
= copy_gimple_seq_and_replace_locals (seq
);
2966 gimple_seq_add_seq (&seq
, gimple_try_eval (two
));
2967 gimple_try_set_eval (two
, seq
);
2971 /* Perform EH refactoring optimizations that are simpler to do when code
2972 flow has been lowered but EH structures haven't. */
2975 refactor_eh_r (gimple_seq seq
)
2977 gimple_stmt_iterator gsi
;
2982 gsi
= gsi_start (seq
);
2986 if (gsi_end_p (gsi
))
2989 two
= gsi_stmt (gsi
);
2992 && gimple_code (one
) == GIMPLE_TRY
2993 && gimple_code (two
) == GIMPLE_TRY
2994 && gimple_try_kind (one
) == GIMPLE_TRY_FINALLY
2995 && gimple_try_kind (two
) == GIMPLE_TRY_FINALLY
)
2996 optimize_double_finally (one
, two
);
2998 switch (gimple_code (one
))
3001 refactor_eh_r (gimple_try_eval (one
));
3002 refactor_eh_r (gimple_try_cleanup (one
));
3005 refactor_eh_r (gimple_catch_handler (one
));
3007 case GIMPLE_EH_FILTER
:
3008 refactor_eh_r (gimple_eh_filter_failure (one
));
3010 case GIMPLE_EH_ELSE
:
3011 refactor_eh_r (gimple_eh_else_n_body (one
));
3012 refactor_eh_r (gimple_eh_else_e_body (one
));
3027 refactor_eh_r (gimple_body (current_function_decl
));
3032 gate_refactor_eh (void)
3034 return flag_exceptions
!= 0;
3039 const pass_data pass_data_refactor_eh
=
3041 GIMPLE_PASS
, /* type */
3043 OPTGROUP_NONE
, /* optinfo_flags */
3044 true, /* has_gate */
3045 true, /* has_execute */
3046 TV_TREE_EH
, /* tv_id */
3047 PROP_gimple_lcf
, /* properties_required */
3048 0, /* properties_provided */
3049 0, /* properties_destroyed */
3050 0, /* todo_flags_start */
3051 0, /* todo_flags_finish */
3054 class pass_refactor_eh
: public gimple_opt_pass
3057 pass_refactor_eh (gcc::context
*ctxt
)
3058 : gimple_opt_pass (pass_data_refactor_eh
, ctxt
)
3061 /* opt_pass methods: */
3062 bool gate () { return gate_refactor_eh (); }
3063 unsigned int execute () { return refactor_eh (); }
3065 }; // class pass_refactor_eh
3070 make_pass_refactor_eh (gcc::context
*ctxt
)
3072 return new pass_refactor_eh (ctxt
);
3075 /* At the end of gimple optimization, we can lower RESX. */
3078 lower_resx (basic_block bb
, gimple stmt
, struct pointer_map_t
*mnt_map
)
3081 eh_region src_r
, dst_r
;
3082 gimple_stmt_iterator gsi
;
3087 lp_nr
= lookup_stmt_eh_lp (stmt
);
3089 dst_r
= get_eh_region_from_lp_number (lp_nr
);
3093 src_r
= get_eh_region_from_number (gimple_resx_region (stmt
));
3094 gsi
= gsi_last_bb (bb
);
3098 /* We can wind up with no source region when pass_cleanup_eh shows
3099 that there are no entries into an eh region and deletes it, but
3100 then the block that contains the resx isn't removed. This can
3101 happen without optimization when the switch statement created by
3102 lower_try_finally_switch isn't simplified to remove the eh case.
3104 Resolve this by expanding the resx node to an abort. */
3106 fn
= builtin_decl_implicit (BUILT_IN_TRAP
);
3107 x
= gimple_build_call (fn
, 0);
3108 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3110 while (EDGE_COUNT (bb
->succs
) > 0)
3111 remove_edge (EDGE_SUCC (bb
, 0));
3115 /* When we have a destination region, we resolve this by copying
3116 the excptr and filter values into place, and changing the edge
3117 to immediately after the landing pad. */
3126 /* We are resuming into a MUST_NOT_CALL region. Expand a call to
3127 the failure decl into a new block, if needed. */
3128 gcc_assert (dst_r
->type
== ERT_MUST_NOT_THROW
);
3130 slot
= pointer_map_contains (mnt_map
, dst_r
);
3133 gimple_stmt_iterator gsi2
;
3135 new_bb
= create_empty_bb (bb
);
3137 add_bb_to_loop (new_bb
, bb
->loop_father
);
3138 lab
= gimple_block_label (new_bb
);
3139 gsi2
= gsi_start_bb (new_bb
);
3141 fn
= dst_r
->u
.must_not_throw
.failure_decl
;
3142 x
= gimple_build_call (fn
, 0);
3143 gimple_set_location (x
, dst_r
->u
.must_not_throw
.failure_loc
);
3144 gsi_insert_after (&gsi2
, x
, GSI_CONTINUE_LINKING
);
3146 slot
= pointer_map_insert (mnt_map
, dst_r
);
3152 new_bb
= label_to_block (lab
);
3155 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3156 e
= make_edge (bb
, new_bb
, EDGE_FALLTHRU
);
3157 e
->count
= bb
->count
;
3158 e
->probability
= REG_BR_PROB_BASE
;
3163 tree dst_nr
= build_int_cst (integer_type_node
, dst_r
->index
);
3165 fn
= builtin_decl_implicit (BUILT_IN_EH_COPY_VALUES
);
3166 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3167 x
= gimple_build_call (fn
, 2, dst_nr
, src_nr
);
3168 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3170 /* Update the flags for the outgoing edge. */
3171 e
= single_succ_edge (bb
);
3172 gcc_assert (e
->flags
& EDGE_EH
);
3173 e
->flags
= (e
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
3175 /* If there are no more EH users of the landing pad, delete it. */
3176 FOR_EACH_EDGE (e
, ei
, e
->dest
->preds
)
3177 if (e
->flags
& EDGE_EH
)
3181 eh_landing_pad lp
= get_eh_landing_pad_from_number (lp_nr
);
3182 remove_eh_landing_pad (lp
);
3192 /* When we don't have a destination region, this exception escapes
3193 up the call chain. We resolve this by generating a call to the
3194 _Unwind_Resume library function. */
3196 /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup
3197 with no arguments for C++ and Java. Check for that. */
3198 if (src_r
->use_cxa_end_cleanup
)
3200 fn
= builtin_decl_implicit (BUILT_IN_CXA_END_CLEANUP
);
3201 x
= gimple_build_call (fn
, 0);
3202 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3206 fn
= builtin_decl_implicit (BUILT_IN_EH_POINTER
);
3207 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3208 x
= gimple_build_call (fn
, 1, src_nr
);
3209 var
= create_tmp_var (ptr_type_node
, NULL
);
3210 var
= make_ssa_name (var
, x
);
3211 gimple_call_set_lhs (x
, var
);
3212 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3214 fn
= builtin_decl_implicit (BUILT_IN_UNWIND_RESUME
);
3215 x
= gimple_build_call (fn
, 1, var
);
3216 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3219 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3222 gsi_remove (&gsi
, true);
3228 execute_lower_resx (void)
3231 struct pointer_map_t
*mnt_map
;
3232 bool dominance_invalidated
= false;
3233 bool any_rewritten
= false;
3235 mnt_map
= pointer_map_create ();
3239 gimple last
= last_stmt (bb
);
3240 if (last
&& is_gimple_resx (last
))
3242 dominance_invalidated
|= lower_resx (bb
, last
, mnt_map
);
3243 any_rewritten
= true;
3247 pointer_map_destroy (mnt_map
);
3249 if (dominance_invalidated
)
3251 free_dominance_info (CDI_DOMINATORS
);
3252 free_dominance_info (CDI_POST_DOMINATORS
);
3255 return any_rewritten
? TODO_update_ssa_only_virtuals
: 0;
3259 gate_lower_resx (void)
3261 return flag_exceptions
!= 0;
3266 const pass_data pass_data_lower_resx
=
3268 GIMPLE_PASS
, /* type */
3270 OPTGROUP_NONE
, /* optinfo_flags */
3271 true, /* has_gate */
3272 true, /* has_execute */
3273 TV_TREE_EH
, /* tv_id */
3274 PROP_gimple_lcf
, /* properties_required */
3275 0, /* properties_provided */
3276 0, /* properties_destroyed */
3277 0, /* todo_flags_start */
3278 TODO_verify_flow
, /* todo_flags_finish */
3281 class pass_lower_resx
: public gimple_opt_pass
3284 pass_lower_resx (gcc::context
*ctxt
)
3285 : gimple_opt_pass (pass_data_lower_resx
, ctxt
)
3288 /* opt_pass methods: */
3289 bool gate () { return gate_lower_resx (); }
3290 unsigned int execute () { return execute_lower_resx (); }
3292 }; // class pass_lower_resx
3297 make_pass_lower_resx (gcc::context
*ctxt
)
3299 return new pass_lower_resx (ctxt
);
3302 /* Try to optimize var = {v} {CLOBBER} stmts followed just by
3306 optimize_clobbers (basic_block bb
)
3308 gimple_stmt_iterator gsi
= gsi_last_bb (bb
);
3309 bool any_clobbers
= false;
3310 bool seen_stack_restore
= false;
3314 /* Only optimize anything if the bb contains at least one clobber,
3315 ends with resx (checked by caller), optionally contains some
3316 debug stmts or labels, or at most one __builtin_stack_restore
3317 call, and has an incoming EH edge. */
3318 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3320 gimple stmt
= gsi_stmt (gsi
);
3321 if (is_gimple_debug (stmt
))
3323 if (gimple_clobber_p (stmt
))
3325 any_clobbers
= true;
3328 if (!seen_stack_restore
3329 && gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
3331 seen_stack_restore
= true;
3334 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3340 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3341 if (e
->flags
& EDGE_EH
)
3345 gsi
= gsi_last_bb (bb
);
3346 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3348 gimple stmt
= gsi_stmt (gsi
);
3349 if (!gimple_clobber_p (stmt
))
3351 unlink_stmt_vdef (stmt
);
3352 gsi_remove (&gsi
, true);
3353 release_defs (stmt
);
3357 /* Try to sink var = {v} {CLOBBER} stmts followed just by
3358 internal throw to successor BB. */
3361 sink_clobbers (basic_block bb
)
3365 gimple_stmt_iterator gsi
, dgsi
;
3367 bool any_clobbers
= false;
3370 /* Only optimize if BB has a single EH successor and
3371 all predecessor edges are EH too. */
3372 if (!single_succ_p (bb
)
3373 || (single_succ_edge (bb
)->flags
& EDGE_EH
) == 0)
3376 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3378 if ((e
->flags
& EDGE_EH
) == 0)
3382 /* And BB contains only CLOBBER stmts before the final
3384 gsi
= gsi_last_bb (bb
);
3385 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3387 gimple stmt
= gsi_stmt (gsi
);
3388 if (is_gimple_debug (stmt
))
3390 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3392 if (!gimple_clobber_p (stmt
))
3394 any_clobbers
= true;
3399 edge succe
= single_succ_edge (bb
);
3400 succbb
= succe
->dest
;
3402 /* See if there is a virtual PHI node to take an updated virtual
3405 tree vuse
= NULL_TREE
;
3406 for (gsi
= gsi_start_phis (succbb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3408 tree res
= gimple_phi_result (gsi_stmt (gsi
));
3409 if (virtual_operand_p (res
))
3411 vphi
= gsi_stmt (gsi
);
3417 dgsi
= gsi_after_labels (succbb
);
3418 gsi
= gsi_last_bb (bb
);
3419 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3421 gimple stmt
= gsi_stmt (gsi
);
3423 if (is_gimple_debug (stmt
))
3425 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3427 lhs
= gimple_assign_lhs (stmt
);
3428 /* Unfortunately we don't have dominance info updated at this
3429 point, so checking if
3430 dominated_by_p (CDI_DOMINATORS, succbb,
3431 gimple_bb (SSA_NAME_DEF_STMT (TREE_OPERAND (lhs, 0)))
3432 would be too costly. Thus, avoid sinking any clobbers that
3433 refer to non-(D) SSA_NAMEs. */
3434 if (TREE_CODE (lhs
) == MEM_REF
3435 && TREE_CODE (TREE_OPERAND (lhs
, 0)) == SSA_NAME
3436 && !SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs
, 0)))
3438 unlink_stmt_vdef (stmt
);
3439 gsi_remove (&gsi
, true);
3440 release_defs (stmt
);
3444 /* As we do not change stmt order when sinking across a
3445 forwarder edge we can keep virtual operands in place. */
3446 gsi_remove (&gsi
, false);
3447 gsi_insert_before (&dgsi
, stmt
, GSI_NEW_STMT
);
3449 /* But adjust virtual operands if we sunk across a PHI node. */
3453 imm_use_iterator iter
;
3454 use_operand_p use_p
;
3455 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, vuse
)
3456 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
3457 SET_USE (use_p
, gimple_vdef (stmt
));
3458 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
))
3460 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vdef (stmt
)) = 1;
3461 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
) = 0;
3463 /* Adjust the incoming virtual operand. */
3464 SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (vphi
, succe
), gimple_vuse (stmt
));
3465 SET_USE (gimple_vuse_op (stmt
), vuse
);
3467 /* If there isn't a single predecessor but no virtual PHI node
3468 arrange for virtual operands to be renamed. */
3469 else if (gimple_vuse_op (stmt
) != NULL_USE_OPERAND_P
3470 && !single_pred_p (succbb
))
3472 /* In this case there will be no use of the VDEF of this stmt.
3473 ??? Unless this is a secondary opportunity and we have not
3474 removed unreachable blocks yet, so we cannot assert this.
3475 Which also means we will end up renaming too many times. */
3476 SET_USE (gimple_vuse_op (stmt
), gimple_vop (cfun
));
3477 mark_virtual_operands_for_renaming (cfun
);
3478 todo
|= TODO_update_ssa_only_virtuals
;
3485 /* At the end of inlining, we can lower EH_DISPATCH. Return true when
3486 we have found some duplicate labels and removed some edges. */
3489 lower_eh_dispatch (basic_block src
, gimple stmt
)
3491 gimple_stmt_iterator gsi
;
3496 bool redirected
= false;
3498 region_nr
= gimple_eh_dispatch_region (stmt
);
3499 r
= get_eh_region_from_number (region_nr
);
3501 gsi
= gsi_last_bb (src
);
3507 vec
<tree
> labels
= vNULL
;
3508 tree default_label
= NULL
;
3512 struct pointer_set_t
*seen_values
= pointer_set_create ();
3514 /* Collect the labels for a switch. Zero the post_landing_pad
3515 field becase we'll no longer have anything keeping these labels
3516 in existence and the optimizer will be free to merge these
3518 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
3520 tree tp_node
, flt_node
, lab
= c
->label
;
3521 bool have_label
= false;
3524 tp_node
= c
->type_list
;
3525 flt_node
= c
->filter_list
;
3527 if (tp_node
== NULL
)
3529 default_label
= lab
;
3534 /* Filter out duplicate labels that arise when this handler
3535 is shadowed by an earlier one. When no labels are
3536 attached to the handler anymore, we remove
3537 the corresponding edge and then we delete unreachable
3538 blocks at the end of this pass. */
3539 if (! pointer_set_contains (seen_values
, TREE_VALUE (flt_node
)))
3541 tree t
= build_case_label (TREE_VALUE (flt_node
),
3543 labels
.safe_push (t
);
3544 pointer_set_insert (seen_values
, TREE_VALUE (flt_node
));
3548 tp_node
= TREE_CHAIN (tp_node
);
3549 flt_node
= TREE_CHAIN (flt_node
);
3554 remove_edge (find_edge (src
, label_to_block (lab
)));
3559 /* Clean up the edge flags. */
3560 FOR_EACH_EDGE (e
, ei
, src
->succs
)
3562 if (e
->flags
& EDGE_FALLTHRU
)
3564 /* If there was no catch-all, use the fallthru edge. */
3565 if (default_label
== NULL
)
3566 default_label
= gimple_block_label (e
->dest
);
3567 e
->flags
&= ~EDGE_FALLTHRU
;
3570 gcc_assert (default_label
!= NULL
);
3572 /* Don't generate a switch if there's only a default case.
3573 This is common in the form of try { A; } catch (...) { B; }. */
3574 if (!labels
.exists ())
3576 e
= single_succ_edge (src
);
3577 e
->flags
|= EDGE_FALLTHRU
;
3581 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3582 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3584 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)), NULL
);
3585 filter
= make_ssa_name (filter
, x
);
3586 gimple_call_set_lhs (x
, filter
);
3587 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3589 /* Turn the default label into a default case. */
3590 default_label
= build_case_label (NULL
, NULL
, default_label
);
3591 sort_case_labels (labels
);
3593 x
= gimple_build_switch (filter
, default_label
, labels
);
3594 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3598 pointer_set_destroy (seen_values
);
3602 case ERT_ALLOWED_EXCEPTIONS
:
3604 edge b_e
= BRANCH_EDGE (src
);
3605 edge f_e
= FALLTHRU_EDGE (src
);
3607 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3608 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3610 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)), NULL
);
3611 filter
= make_ssa_name (filter
, x
);
3612 gimple_call_set_lhs (x
, filter
);
3613 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3615 r
->u
.allowed
.label
= NULL
;
3616 x
= gimple_build_cond (EQ_EXPR
, filter
,
3617 build_int_cst (TREE_TYPE (filter
),
3618 r
->u
.allowed
.filter
),
3619 NULL_TREE
, NULL_TREE
);
3620 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3622 b_e
->flags
= b_e
->flags
| EDGE_TRUE_VALUE
;
3623 f_e
->flags
= (f_e
->flags
& ~EDGE_FALLTHRU
) | EDGE_FALSE_VALUE
;
3631 /* Replace the EH_DISPATCH with the SWITCH or COND generated above. */
3632 gsi_remove (&gsi
, true);
3637 execute_lower_eh_dispatch (void)
3641 bool redirected
= false;
3643 assign_filter_values ();
3647 gimple last
= last_stmt (bb
);
3650 if (gimple_code (last
) == GIMPLE_EH_DISPATCH
)
3652 redirected
|= lower_eh_dispatch (bb
, last
);
3653 flags
|= TODO_update_ssa_only_virtuals
;
3655 else if (gimple_code (last
) == GIMPLE_RESX
)
3657 if (stmt_can_throw_external (last
))
3658 optimize_clobbers (bb
);
3660 flags
|= sink_clobbers (bb
);
3665 delete_unreachable_blocks ();
3670 gate_lower_eh_dispatch (void)
3672 return cfun
->eh
->region_tree
!= NULL
;
3677 const pass_data pass_data_lower_eh_dispatch
=
3679 GIMPLE_PASS
, /* type */
3680 "ehdisp", /* name */
3681 OPTGROUP_NONE
, /* optinfo_flags */
3682 true, /* has_gate */
3683 true, /* has_execute */
3684 TV_TREE_EH
, /* tv_id */
3685 PROP_gimple_lcf
, /* properties_required */
3686 0, /* properties_provided */
3687 0, /* properties_destroyed */
3688 0, /* todo_flags_start */
3689 TODO_verify_flow
, /* todo_flags_finish */
3692 class pass_lower_eh_dispatch
: public gimple_opt_pass
3695 pass_lower_eh_dispatch (gcc::context
*ctxt
)
3696 : gimple_opt_pass (pass_data_lower_eh_dispatch
, ctxt
)
3699 /* opt_pass methods: */
3700 bool gate () { return gate_lower_eh_dispatch (); }
3701 unsigned int execute () { return execute_lower_eh_dispatch (); }
3703 }; // class pass_lower_eh_dispatch
3708 make_pass_lower_eh_dispatch (gcc::context
*ctxt
)
3710 return new pass_lower_eh_dispatch (ctxt
);
3713 /* Walk statements, see what regions and, optionally, landing pads
3714 are really referenced.
3716 Returns in R_REACHABLEP an sbitmap with bits set for reachable regions,
3717 and in LP_REACHABLE an sbitmap with bits set for reachable landing pads.
3719 Passing NULL for LP_REACHABLE is valid, in this case only reachable
3722 The caller is responsible for freeing the returned sbitmaps. */
3725 mark_reachable_handlers (sbitmap
*r_reachablep
, sbitmap
*lp_reachablep
)
3727 sbitmap r_reachable
, lp_reachable
;
3729 bool mark_landing_pads
= (lp_reachablep
!= NULL
);
3730 gcc_checking_assert (r_reachablep
!= NULL
);
3732 r_reachable
= sbitmap_alloc (cfun
->eh
->region_array
->length ());
3733 bitmap_clear (r_reachable
);
3734 *r_reachablep
= r_reachable
;
3736 if (mark_landing_pads
)
3738 lp_reachable
= sbitmap_alloc (cfun
->eh
->lp_array
->length ());
3739 bitmap_clear (lp_reachable
);
3740 *lp_reachablep
= lp_reachable
;
3743 lp_reachable
= NULL
;
3747 gimple_stmt_iterator gsi
;
3749 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3751 gimple stmt
= gsi_stmt (gsi
);
3753 if (mark_landing_pads
)
3755 int lp_nr
= lookup_stmt_eh_lp (stmt
);
3757 /* Negative LP numbers are MUST_NOT_THROW regions which
3758 are not considered BB enders. */
3760 bitmap_set_bit (r_reachable
, -lp_nr
);
3762 /* Positive LP numbers are real landing pads, and BB enders. */
3765 gcc_assert (gsi_one_before_end_p (gsi
));
3766 eh_region region
= get_eh_region_from_lp_number (lp_nr
);
3767 bitmap_set_bit (r_reachable
, region
->index
);
3768 bitmap_set_bit (lp_reachable
, lp_nr
);
3772 /* Avoid removing regions referenced from RESX/EH_DISPATCH. */
3773 switch (gimple_code (stmt
))
3776 bitmap_set_bit (r_reachable
, gimple_resx_region (stmt
));
3778 case GIMPLE_EH_DISPATCH
:
3779 bitmap_set_bit (r_reachable
, gimple_eh_dispatch_region (stmt
));
3788 /* Remove unreachable handlers and unreachable landing pads. */
3791 remove_unreachable_handlers (void)
3793 sbitmap r_reachable
, lp_reachable
;
3798 mark_reachable_handlers (&r_reachable
, &lp_reachable
);
3802 fprintf (dump_file
, "Before removal of unreachable regions:\n");
3803 dump_eh_tree (dump_file
, cfun
);
3804 fprintf (dump_file
, "Reachable regions: ");
3805 dump_bitmap_file (dump_file
, r_reachable
);
3806 fprintf (dump_file
, "Reachable landing pads: ");
3807 dump_bitmap_file (dump_file
, lp_reachable
);
3812 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3813 if (region
&& !bitmap_bit_p (r_reachable
, region
->index
))
3815 "Removing unreachable region %d\n",
3819 remove_unreachable_eh_regions (r_reachable
);
3821 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3822 if (lp
&& !bitmap_bit_p (lp_reachable
, lp
->index
))
3826 "Removing unreachable landing pad %d\n",
3828 remove_eh_landing_pad (lp
);
3833 fprintf (dump_file
, "\n\nAfter removal of unreachable regions:\n");
3834 dump_eh_tree (dump_file
, cfun
);
3835 fprintf (dump_file
, "\n\n");
3838 sbitmap_free (r_reachable
);
3839 sbitmap_free (lp_reachable
);
3841 #ifdef ENABLE_CHECKING
3842 verify_eh_tree (cfun
);
3846 /* Remove unreachable handlers if any landing pads have been removed after
3847 last ehcleanup pass (due to gimple_purge_dead_eh_edges). */
3850 maybe_remove_unreachable_handlers (void)
3855 if (cfun
->eh
== NULL
)
3858 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3859 if (lp
&& lp
->post_landing_pad
)
3861 if (label_to_block (lp
->post_landing_pad
) == NULL
)
3863 remove_unreachable_handlers ();
3869 /* Remove regions that do not have landing pads. This assumes
3870 that remove_unreachable_handlers has already been run, and
3871 that we've just manipulated the landing pads since then.
3873 Preserve regions with landing pads and regions that prevent
3874 exceptions from propagating further, even if these regions
3875 are not reachable. */
3878 remove_unreachable_handlers_no_lp (void)
3881 sbitmap r_reachable
;
3884 mark_reachable_handlers (&r_reachable
, /*lp_reachablep=*/NULL
);
3886 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3891 if (region
->landing_pads
!= NULL
3892 || region
->type
== ERT_MUST_NOT_THROW
)
3893 bitmap_set_bit (r_reachable
, region
->index
);
3896 && !bitmap_bit_p (r_reachable
, region
->index
))
3898 "Removing unreachable region %d\n",
3902 remove_unreachable_eh_regions (r_reachable
);
3904 sbitmap_free (r_reachable
);
3907 /* Undo critical edge splitting on an EH landing pad. Earlier, we
3908 optimisticaly split all sorts of edges, including EH edges. The
3909 optimization passes in between may not have needed them; if not,
3910 we should undo the split.
3912 Recognize this case by having one EH edge incoming to the BB and
3913 one normal edge outgoing; BB should be empty apart from the
3914 post_landing_pad label.
3916 Note that this is slightly different from the empty handler case
3917 handled by cleanup_empty_eh, in that the actual handler may yet
3918 have actual code but the landing pad has been separated from the
3919 handler. As such, cleanup_empty_eh relies on this transformation
3920 having been done first. */
3923 unsplit_eh (eh_landing_pad lp
)
3925 basic_block bb
= label_to_block (lp
->post_landing_pad
);
3926 gimple_stmt_iterator gsi
;
3929 /* Quickly check the edge counts on BB for singularity. */
3930 if (!single_pred_p (bb
) || !single_succ_p (bb
))
3932 e_in
= single_pred_edge (bb
);
3933 e_out
= single_succ_edge (bb
);
3935 /* Input edge must be EH and output edge must be normal. */
3936 if ((e_in
->flags
& EDGE_EH
) == 0 || (e_out
->flags
& EDGE_EH
) != 0)
3939 /* The block must be empty except for the labels and debug insns. */
3940 gsi
= gsi_after_labels (bb
);
3941 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
3942 gsi_next_nondebug (&gsi
);
3943 if (!gsi_end_p (gsi
))
3946 /* The destination block must not already have a landing pad
3947 for a different region. */
3948 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3950 gimple stmt
= gsi_stmt (gsi
);
3954 if (gimple_code (stmt
) != GIMPLE_LABEL
)
3956 lab
= gimple_label_label (stmt
);
3957 lp_nr
= EH_LANDING_PAD_NR (lab
);
3958 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
3962 /* The new destination block must not already be a destination of
3963 the source block, lest we merge fallthru and eh edges and get
3964 all sorts of confused. */
3965 if (find_edge (e_in
->src
, e_out
->dest
))
3968 /* ??? We can get degenerate phis due to cfg cleanups. I would have
3969 thought this should have been cleaned up by a phicprop pass, but
3970 that doesn't appear to handle virtuals. Propagate by hand. */
3971 if (!gimple_seq_empty_p (phi_nodes (bb
)))
3973 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); )
3975 gimple use_stmt
, phi
= gsi_stmt (gsi
);
3976 tree lhs
= gimple_phi_result (phi
);
3977 tree rhs
= gimple_phi_arg_def (phi
, 0);
3978 use_operand_p use_p
;
3979 imm_use_iterator iter
;
3981 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
3983 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
3984 SET_USE (use_p
, rhs
);
3987 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
3988 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs
) = 1;
3990 remove_phi_node (&gsi
, true);
3994 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
3995 fprintf (dump_file
, "Unsplit EH landing pad %d to block %i.\n",
3996 lp
->index
, e_out
->dest
->index
);
3998 /* Redirect the edge. Since redirect_eh_edge_1 expects to be moving
3999 a successor edge, humor it. But do the real CFG change with the
4000 predecessor of E_OUT in order to preserve the ordering of arguments
4001 to the PHI nodes in E_OUT->DEST. */
4002 redirect_eh_edge_1 (e_in
, e_out
->dest
, false);
4003 redirect_edge_pred (e_out
, e_in
->src
);
4004 e_out
->flags
= e_in
->flags
;
4005 e_out
->probability
= e_in
->probability
;
4006 e_out
->count
= e_in
->count
;
4012 /* Examine each landing pad block and see if it matches unsplit_eh. */
4015 unsplit_all_eh (void)
4017 bool changed
= false;
4021 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4023 changed
|= unsplit_eh (lp
);
4028 /* A subroutine of cleanup_empty_eh. Redirect all EH edges incoming
4029 to OLD_BB to NEW_BB; return true on success, false on failure.
4031 OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any
4032 PHI variables from OLD_BB we can pick them up from OLD_BB_OUT.
4033 Virtual PHIs may be deleted and marked for renaming. */
4036 cleanup_empty_eh_merge_phis (basic_block new_bb
, basic_block old_bb
,
4037 edge old_bb_out
, bool change_region
)
4039 gimple_stmt_iterator ngsi
, ogsi
;
4042 bitmap ophi_handled
;
4044 /* The destination block must not be a regular successor for any
4045 of the preds of the landing pad. Thus, avoid turning
4055 which CFG verification would choke on. See PR45172 and PR51089. */
4056 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4057 if (find_edge (e
->src
, new_bb
))
4060 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4061 redirect_edge_var_map_clear (e
);
4063 ophi_handled
= BITMAP_ALLOC (NULL
);
4065 /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
4066 for the edges we're going to move. */
4067 for (ngsi
= gsi_start_phis (new_bb
); !gsi_end_p (ngsi
); gsi_next (&ngsi
))
4069 gimple ophi
, nphi
= gsi_stmt (ngsi
);
4072 nresult
= gimple_phi_result (nphi
);
4073 nop
= gimple_phi_arg_def (nphi
, old_bb_out
->dest_idx
);
4075 /* Find the corresponding PHI in OLD_BB so we can forward-propagate
4076 the source ssa_name. */
4078 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4080 ophi
= gsi_stmt (ogsi
);
4081 if (gimple_phi_result (ophi
) == nop
)
4086 /* If we did find the corresponding PHI, copy those inputs. */
4089 /* If NOP is used somewhere else beyond phis in new_bb, give up. */
4090 if (!has_single_use (nop
))
4092 imm_use_iterator imm_iter
;
4093 use_operand_p use_p
;
4095 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, nop
)
4097 if (!gimple_debug_bind_p (USE_STMT (use_p
))
4098 && (gimple_code (USE_STMT (use_p
)) != GIMPLE_PHI
4099 || gimple_bb (USE_STMT (use_p
)) != new_bb
))
4103 bitmap_set_bit (ophi_handled
, SSA_NAME_VERSION (nop
));
4104 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4109 if ((e
->flags
& EDGE_EH
) == 0)
4111 oop
= gimple_phi_arg_def (ophi
, e
->dest_idx
);
4112 oloc
= gimple_phi_arg_location (ophi
, e
->dest_idx
);
4113 redirect_edge_var_map_add (e
, nresult
, oop
, oloc
);
4116 /* If we didn't find the PHI, if it's a real variable or a VOP, we know
4117 from the fact that OLD_BB is tree_empty_eh_handler_p that the
4118 variable is unchanged from input to the block and we can simply
4119 re-use the input to NEW_BB from the OLD_BB_OUT edge. */
4123 = gimple_phi_arg_location (nphi
, old_bb_out
->dest_idx
);
4124 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4125 redirect_edge_var_map_add (e
, nresult
, nop
, nloc
);
4129 /* Second, verify that all PHIs from OLD_BB have been handled. If not,
4130 we don't know what values from the other edges into NEW_BB to use. */
4131 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4133 gimple ophi
= gsi_stmt (ogsi
);
4134 tree oresult
= gimple_phi_result (ophi
);
4135 if (!bitmap_bit_p (ophi_handled
, SSA_NAME_VERSION (oresult
)))
4139 /* Finally, move the edges and update the PHIs. */
4140 for (ei
= ei_start (old_bb
->preds
); (e
= ei_safe_edge (ei
)); )
4141 if (e
->flags
& EDGE_EH
)
4143 /* ??? CFG manipluation routines do not try to update loop
4144 form on edge redirection. Do so manually here for now. */
4145 /* If we redirect a loop entry or latch edge that will either create
4146 a multiple entry loop or rotate the loop. If the loops merge
4147 we may have created a loop with multiple latches.
4148 All of this isn't easily fixed thus cancel the affected loop
4149 and mark the other loop as possibly having multiple latches. */
4151 && e
->dest
== e
->dest
->loop_father
->header
)
4153 e
->dest
->loop_father
->header
= NULL
;
4154 e
->dest
->loop_father
->latch
= NULL
;
4155 new_bb
->loop_father
->latch
= NULL
;
4156 loops_state_set (LOOPS_NEED_FIXUP
|LOOPS_MAY_HAVE_MULTIPLE_LATCHES
);
4158 redirect_eh_edge_1 (e
, new_bb
, change_region
);
4159 redirect_edge_succ (e
, new_bb
);
4160 flush_pending_stmts (e
);
4165 BITMAP_FREE (ophi_handled
);
4169 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4170 redirect_edge_var_map_clear (e
);
4171 BITMAP_FREE (ophi_handled
);
4175 /* A subroutine of cleanup_empty_eh. Move a landing pad LP from its
4176 old region to NEW_REGION at BB. */
4179 cleanup_empty_eh_move_lp (basic_block bb
, edge e_out
,
4180 eh_landing_pad lp
, eh_region new_region
)
4182 gimple_stmt_iterator gsi
;
4185 for (pp
= &lp
->region
->landing_pads
; *pp
!= lp
; pp
= &(*pp
)->next_lp
)
4189 lp
->region
= new_region
;
4190 lp
->next_lp
= new_region
->landing_pads
;
4191 new_region
->landing_pads
= lp
;
4193 /* Delete the RESX that was matched within the empty handler block. */
4194 gsi
= gsi_last_bb (bb
);
4195 unlink_stmt_vdef (gsi_stmt (gsi
));
4196 gsi_remove (&gsi
, true);
4198 /* Clean up E_OUT for the fallthru. */
4199 e_out
->flags
= (e_out
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
4200 e_out
->probability
= REG_BR_PROB_BASE
;
4203 /* A subroutine of cleanup_empty_eh. Handle more complex cases of
4204 unsplitting than unsplit_eh was prepared to handle, e.g. when
4205 multiple incoming edges and phis are involved. */
4208 cleanup_empty_eh_unsplit (basic_block bb
, edge e_out
, eh_landing_pad lp
)
4210 gimple_stmt_iterator gsi
;
4213 /* We really ought not have totally lost everything following
4214 a landing pad label. Given that BB is empty, there had better
4216 gcc_assert (e_out
!= NULL
);
4218 /* The destination block must not already have a landing pad
4219 for a different region. */
4221 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4223 gimple stmt
= gsi_stmt (gsi
);
4226 if (gimple_code (stmt
) != GIMPLE_LABEL
)
4228 lab
= gimple_label_label (stmt
);
4229 lp_nr
= EH_LANDING_PAD_NR (lab
);
4230 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4234 /* Attempt to move the PHIs into the successor block. */
4235 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, false))
4237 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4239 "Unsplit EH landing pad %d to block %i "
4240 "(via cleanup_empty_eh).\n",
4241 lp
->index
, e_out
->dest
->index
);
4248 /* Return true if edge E_FIRST is part of an empty infinite loop
4249 or leads to such a loop through a series of single successor
4253 infinite_empty_loop_p (edge e_first
)
4255 bool inf_loop
= false;
4258 if (e_first
->dest
== e_first
->src
)
4261 e_first
->src
->aux
= (void *) 1;
4262 for (e
= e_first
; single_succ_p (e
->dest
); e
= single_succ_edge (e
->dest
))
4264 gimple_stmt_iterator gsi
;
4270 e
->dest
->aux
= (void *) 1;
4271 gsi
= gsi_after_labels (e
->dest
);
4272 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4273 gsi_next_nondebug (&gsi
);
4274 if (!gsi_end_p (gsi
))
4277 e_first
->src
->aux
= NULL
;
4278 for (e
= e_first
; e
->dest
->aux
; e
= single_succ_edge (e
->dest
))
4279 e
->dest
->aux
= NULL
;
4284 /* Examine the block associated with LP to determine if it's an empty
4285 handler for its EH region. If so, attempt to redirect EH edges to
4286 an outer region. Return true the CFG was updated in any way. This
4287 is similar to jump forwarding, just across EH edges. */
4290 cleanup_empty_eh (eh_landing_pad lp
)
4292 basic_block bb
= label_to_block (lp
->post_landing_pad
);
4293 gimple_stmt_iterator gsi
;
4295 eh_region new_region
;
4298 bool has_non_eh_pred
;
4302 /* There can be zero or one edges out of BB. This is the quickest test. */
4303 switch (EDGE_COUNT (bb
->succs
))
4309 e_out
= single_succ_edge (bb
);
4315 resx
= last_stmt (bb
);
4316 if (resx
&& is_gimple_resx (resx
))
4318 if (stmt_can_throw_external (resx
))
4319 optimize_clobbers (bb
);
4320 else if (sink_clobbers (bb
))
4324 gsi
= gsi_after_labels (bb
);
4326 /* Make sure to skip debug statements. */
4327 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4328 gsi_next_nondebug (&gsi
);
4330 /* If the block is totally empty, look for more unsplitting cases. */
4331 if (gsi_end_p (gsi
))
4333 /* For the degenerate case of an infinite loop bail out. */
4334 if (infinite_empty_loop_p (e_out
))
4337 return ret
| cleanup_empty_eh_unsplit (bb
, e_out
, lp
);
4340 /* The block should consist only of a single RESX statement, modulo a
4341 preceding call to __builtin_stack_restore if there is no outgoing
4342 edge, since the call can be eliminated in this case. */
4343 resx
= gsi_stmt (gsi
);
4344 if (!e_out
&& gimple_call_builtin_p (resx
, BUILT_IN_STACK_RESTORE
))
4347 resx
= gsi_stmt (gsi
);
4349 if (!is_gimple_resx (resx
))
4351 gcc_assert (gsi_one_before_end_p (gsi
));
4353 /* Determine if there are non-EH edges, or resx edges into the handler. */
4354 has_non_eh_pred
= false;
4355 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4356 if (!(e
->flags
& EDGE_EH
))
4357 has_non_eh_pred
= true;
4359 /* Find the handler that's outer of the empty handler by looking at
4360 where the RESX instruction was vectored. */
4361 new_lp_nr
= lookup_stmt_eh_lp (resx
);
4362 new_region
= get_eh_region_from_lp_number (new_lp_nr
);
4364 /* If there's no destination region within the current function,
4365 redirection is trivial via removing the throwing statements from
4366 the EH region, removing the EH edges, and allowing the block
4367 to go unreachable. */
4368 if (new_region
== NULL
)
4370 gcc_assert (e_out
== NULL
);
4371 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4372 if (e
->flags
& EDGE_EH
)
4374 gimple stmt
= last_stmt (e
->src
);
4375 remove_stmt_from_eh_lp (stmt
);
4383 /* If the destination region is a MUST_NOT_THROW, allow the runtime
4384 to handle the abort and allow the blocks to go unreachable. */
4385 if (new_region
->type
== ERT_MUST_NOT_THROW
)
4387 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4388 if (e
->flags
& EDGE_EH
)
4390 gimple stmt
= last_stmt (e
->src
);
4391 remove_stmt_from_eh_lp (stmt
);
4392 add_stmt_to_eh_lp (stmt
, new_lp_nr
);
4400 /* Try to redirect the EH edges and merge the PHIs into the destination
4401 landing pad block. If the merge succeeds, we'll already have redirected
4402 all the EH edges. The handler itself will go unreachable if there were
4404 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, true))
4407 /* Finally, if all input edges are EH edges, then we can (potentially)
4408 reduce the number of transfers from the runtime by moving the landing
4409 pad from the original region to the new region. This is a win when
4410 we remove the last CLEANUP region along a particular exception
4411 propagation path. Since nothing changes except for the region with
4412 which the landing pad is associated, the PHI nodes do not need to be
4414 if (!has_non_eh_pred
)
4416 cleanup_empty_eh_move_lp (bb
, e_out
, lp
, new_region
);
4417 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4418 fprintf (dump_file
, "Empty EH handler %i moved to EH region %i.\n",
4419 lp
->index
, new_region
->index
);
4421 /* ??? The CFG didn't change, but we may have rendered the
4422 old EH region unreachable. Trigger a cleanup there. */
4429 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4430 fprintf (dump_file
, "Empty EH handler %i removed.\n", lp
->index
);
4431 remove_eh_landing_pad (lp
);
4435 /* Do a post-order traversal of the EH region tree. Examine each
4436 post_landing_pad block and see if we can eliminate it as empty. */
4439 cleanup_all_empty_eh (void)
4441 bool changed
= false;
4445 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4447 changed
|= cleanup_empty_eh (lp
);
4452 /* Perform cleanups and lowering of exception handling
4453 1) cleanups regions with handlers doing nothing are optimized out
4454 2) MUST_NOT_THROW regions that became dead because of 1) are optimized out
4455 3) Info about regions that are containing instructions, and regions
4456 reachable via local EH edges is collected
4457 4) Eh tree is pruned for regions no longer necessary.
4459 TODO: Push MUST_NOT_THROW regions to the root of the EH tree.
4460 Unify those that have the same failure decl and locus.
4464 execute_cleanup_eh_1 (void)
4466 /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
4467 looking up unreachable landing pads. */
4468 remove_unreachable_handlers ();
4470 /* Watch out for the region tree vanishing due to all unreachable. */
4471 if (cfun
->eh
->region_tree
&& optimize
)
4473 bool changed
= false;
4475 changed
|= unsplit_all_eh ();
4476 changed
|= cleanup_all_empty_eh ();
4480 free_dominance_info (CDI_DOMINATORS
);
4481 free_dominance_info (CDI_POST_DOMINATORS
);
4483 /* We delayed all basic block deletion, as we may have performed
4484 cleanups on EH edges while non-EH edges were still present. */
4485 delete_unreachable_blocks ();
4487 /* We manipulated the landing pads. Remove any region that no
4488 longer has a landing pad. */
4489 remove_unreachable_handlers_no_lp ();
4491 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
4499 execute_cleanup_eh (void)
4501 int ret
= execute_cleanup_eh_1 ();
4503 /* If the function no longer needs an EH personality routine
4504 clear it. This exposes cross-language inlining opportunities
4505 and avoids references to a never defined personality routine. */
4506 if (DECL_FUNCTION_PERSONALITY (current_function_decl
)
4507 && function_needs_eh_personality (cfun
) != eh_personality_lang
)
4508 DECL_FUNCTION_PERSONALITY (current_function_decl
) = NULL_TREE
;
4514 gate_cleanup_eh (void)
4516 return cfun
->eh
!= NULL
&& cfun
->eh
->region_tree
!= NULL
;
4521 const pass_data pass_data_cleanup_eh
=
4523 GIMPLE_PASS
, /* type */
4524 "ehcleanup", /* name */
4525 OPTGROUP_NONE
, /* optinfo_flags */
4526 true, /* has_gate */
4527 true, /* has_execute */
4528 TV_TREE_EH
, /* tv_id */
4529 PROP_gimple_lcf
, /* properties_required */
4530 0, /* properties_provided */
4531 0, /* properties_destroyed */
4532 0, /* todo_flags_start */
4533 TODO_verify_ssa
, /* todo_flags_finish */
4536 class pass_cleanup_eh
: public gimple_opt_pass
4539 pass_cleanup_eh (gcc::context
*ctxt
)
4540 : gimple_opt_pass (pass_data_cleanup_eh
, ctxt
)
4543 /* opt_pass methods: */
4544 opt_pass
* clone () { return new pass_cleanup_eh (m_ctxt
); }
4545 bool gate () { return gate_cleanup_eh (); }
4546 unsigned int execute () { return execute_cleanup_eh (); }
4548 }; // class pass_cleanup_eh
4553 make_pass_cleanup_eh (gcc::context
*ctxt
)
4555 return new pass_cleanup_eh (ctxt
);
4558 /* Verify that BB containing STMT as the last statement, has precisely the
4559 edge that make_eh_edges would create. */
4562 verify_eh_edges (gimple stmt
)
4564 basic_block bb
= gimple_bb (stmt
);
4565 eh_landing_pad lp
= NULL
;
4570 lp_nr
= lookup_stmt_eh_lp (stmt
);
4572 lp
= get_eh_landing_pad_from_number (lp_nr
);
4575 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4577 if (e
->flags
& EDGE_EH
)
4581 error ("BB %i has multiple EH edges", bb
->index
);
4593 error ("BB %i can not throw but has an EH edge", bb
->index
);
4599 if (!stmt_could_throw_p (stmt
))
4601 error ("BB %i last statement has incorrectly set lp", bb
->index
);
4605 if (eh_edge
== NULL
)
4607 error ("BB %i is missing an EH edge", bb
->index
);
4611 if (eh_edge
->dest
!= label_to_block (lp
->post_landing_pad
))
4613 error ("Incorrect EH edge %i->%i", bb
->index
, eh_edge
->dest
->index
);
4620 /* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */
4623 verify_eh_dispatch_edge (gimple stmt
)
4627 basic_block src
, dst
;
4628 bool want_fallthru
= true;
4632 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
4633 src
= gimple_bb (stmt
);
4635 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4636 gcc_assert (e
->aux
== NULL
);
4641 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
4643 dst
= label_to_block (c
->label
);
4644 e
= find_edge (src
, dst
);
4647 error ("BB %i is missing an edge", src
->index
);
4652 /* A catch-all handler doesn't have a fallthru. */
4653 if (c
->type_list
== NULL
)
4655 want_fallthru
= false;
4661 case ERT_ALLOWED_EXCEPTIONS
:
4662 dst
= label_to_block (r
->u
.allowed
.label
);
4663 e
= find_edge (src
, dst
);
4666 error ("BB %i is missing an edge", src
->index
);
4677 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4679 if (e
->flags
& EDGE_FALLTHRU
)
4681 if (fall_edge
!= NULL
)
4683 error ("BB %i too many fallthru edges", src
->index
);
4692 error ("BB %i has incorrect edge", src
->index
);
4696 if ((fall_edge
!= NULL
) ^ want_fallthru
)
4698 error ("BB %i has incorrect fallthru edge", src
->index
);