1 /* Exception handling semantics and decomposition for trees.
2 Copyright (C) 2003-2018 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"
28 #include "tree-pass.h"
31 #include "diagnostic-core.h"
32 #include "fold-const.h"
36 #include "cfgcleanup.h"
38 #include "gimple-iterator.h"
40 #include "tree-into-ssa.h"
42 #include "tree-inline.h"
43 #include "langhooks.h"
45 #include "gimple-low.h"
46 #include "stringpool.h"
51 /* In some instances a tree and a gimple need to be stored in a same table,
52 i.e. in hash tables. This is a structure to do this. */
53 typedef union {tree
*tp
; tree t
; gimple
*g
;} treemple
;
55 /* Misc functions used in this file. */
57 /* Remember and lookup EH landing pad data for arbitrary statements.
58 Really this means any statement that could_throw_p. We could
59 stuff this information into the stmt_ann data structure, but:
61 (1) We absolutely rely on this information being kept until
62 we get to rtl. Once we're done with lowering here, if we lose
63 the information there's no way to recover it!
65 (2) There are many more statements that *cannot* throw as
66 compared to those that can. We should be saving some amount
67 of space by only allocating memory for those that can throw. */
69 /* Add statement T in function IFUN to landing pad NUM. */
72 add_stmt_to_eh_lp_fn (struct function
*ifun
, gimple
*t
, int num
)
74 gcc_assert (num
!= 0);
76 if (!get_eh_throw_stmt_table (ifun
))
77 set_eh_throw_stmt_table (ifun
, hash_map
<gimple
*, int>::create_ggc (31));
79 gcc_assert (!get_eh_throw_stmt_table (ifun
)->put (t
, num
));
82 /* Add statement T in the current function (cfun) to EH landing pad NUM. */
85 add_stmt_to_eh_lp (gimple
*t
, int num
)
87 add_stmt_to_eh_lp_fn (cfun
, t
, num
);
90 /* Add statement T to the single EH landing pad in REGION. */
93 record_stmt_eh_region (eh_region region
, gimple
*t
)
97 if (region
->type
== ERT_MUST_NOT_THROW
)
98 add_stmt_to_eh_lp_fn (cfun
, t
, -region
->index
);
101 eh_landing_pad lp
= region
->landing_pads
;
103 lp
= gen_eh_landing_pad (region
);
105 gcc_assert (lp
->next_lp
== NULL
);
106 add_stmt_to_eh_lp_fn (cfun
, t
, lp
->index
);
111 /* Remove statement T in function IFUN from its EH landing pad. */
114 remove_stmt_from_eh_lp_fn (struct function
*ifun
, gimple
*t
)
116 if (!get_eh_throw_stmt_table (ifun
))
119 if (!get_eh_throw_stmt_table (ifun
)->get (t
))
122 get_eh_throw_stmt_table (ifun
)->remove (t
);
127 /* Remove statement T in the current function (cfun) from its
131 remove_stmt_from_eh_lp (gimple
*t
)
133 return remove_stmt_from_eh_lp_fn (cfun
, t
);
136 /* Determine if statement T is inside an EH region in function IFUN.
137 Positive numbers indicate a landing pad index; negative numbers
138 indicate a MUST_NOT_THROW region index; zero indicates that the
139 statement is not recorded in the region table. */
142 lookup_stmt_eh_lp_fn (struct function
*ifun
, gimple
*t
)
144 if (ifun
->eh
->throw_stmt_table
== NULL
)
147 int *lp_nr
= ifun
->eh
->throw_stmt_table
->get (t
);
148 return lp_nr
? *lp_nr
: 0;
151 /* Likewise, but always use the current function. */
154 lookup_stmt_eh_lp (gimple
*t
)
156 /* We can get called from initialized data when -fnon-call-exceptions
157 is on; prevent crash. */
160 return lookup_stmt_eh_lp_fn (cfun
, t
);
163 /* First pass of EH node decomposition. Build up a tree of GIMPLE_TRY_FINALLY
164 nodes and LABEL_DECL nodes. We will use this during the second phase to
165 determine if a goto leaves the body of a TRY_FINALLY_EXPR node. */
167 struct finally_tree_node
169 /* When storing a GIMPLE_TRY, we have to record a gimple. However
170 when deciding whether a GOTO to a certain LABEL_DECL (which is a
171 tree) leaves the TRY block, its necessary to record a tree in
172 this field. Thus a treemple is used. */
177 /* Hashtable helpers. */
179 struct finally_tree_hasher
: free_ptr_hash
<finally_tree_node
>
181 static inline hashval_t
hash (const finally_tree_node
*);
182 static inline bool equal (const finally_tree_node
*,
183 const finally_tree_node
*);
187 finally_tree_hasher::hash (const finally_tree_node
*v
)
189 return (intptr_t)v
->child
.t
>> 4;
193 finally_tree_hasher::equal (const finally_tree_node
*v
,
194 const finally_tree_node
*c
)
196 return v
->child
.t
== c
->child
.t
;
199 /* Note that this table is *not* marked GTY. It is short-lived. */
200 static hash_table
<finally_tree_hasher
> *finally_tree
;
203 record_in_finally_tree (treemple child
, gtry
*parent
)
205 struct finally_tree_node
*n
;
206 finally_tree_node
**slot
;
208 n
= XNEW (struct finally_tree_node
);
212 slot
= finally_tree
->find_slot (n
, INSERT
);
218 collect_finally_tree (gimple
*stmt
, gtry
*region
);
220 /* Go through the gimple sequence. Works with collect_finally_tree to
221 record all GIMPLE_LABEL and GIMPLE_TRY statements. */
224 collect_finally_tree_1 (gimple_seq seq
, gtry
*region
)
226 gimple_stmt_iterator gsi
;
228 for (gsi
= gsi_start (seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
229 collect_finally_tree (gsi_stmt (gsi
), region
);
233 collect_finally_tree (gimple
*stmt
, gtry
*region
)
237 switch (gimple_code (stmt
))
240 temp
.t
= gimple_label_label (as_a
<glabel
*> (stmt
));
241 record_in_finally_tree (temp
, region
);
245 if (gimple_try_kind (stmt
) == GIMPLE_TRY_FINALLY
)
248 record_in_finally_tree (temp
, region
);
249 collect_finally_tree_1 (gimple_try_eval (stmt
),
250 as_a
<gtry
*> (stmt
));
251 collect_finally_tree_1 (gimple_try_cleanup (stmt
), region
);
253 else if (gimple_try_kind (stmt
) == GIMPLE_TRY_CATCH
)
255 collect_finally_tree_1 (gimple_try_eval (stmt
), region
);
256 collect_finally_tree_1 (gimple_try_cleanup (stmt
), region
);
261 collect_finally_tree_1 (gimple_catch_handler (
262 as_a
<gcatch
*> (stmt
)),
266 case GIMPLE_EH_FILTER
:
267 collect_finally_tree_1 (gimple_eh_filter_failure (stmt
), region
);
272 geh_else
*eh_else_stmt
= as_a
<geh_else
*> (stmt
);
273 collect_finally_tree_1 (gimple_eh_else_n_body (eh_else_stmt
), region
);
274 collect_finally_tree_1 (gimple_eh_else_e_body (eh_else_stmt
), region
);
279 /* A type, a decl, or some kind of statement that we're not
280 interested in. Don't walk them. */
286 /* Use the finally tree to determine if a jump from START to TARGET
287 would leave the try_finally node that START lives in. */
290 outside_finally_tree (treemple start
, gimple
*target
)
292 struct finally_tree_node n
, *p
;
297 p
= finally_tree
->find (&n
);
302 while (start
.g
!= target
);
307 /* Second pass of EH node decomposition. Actually transform the GIMPLE_TRY
308 nodes into a set of gotos, magic labels, and eh regions.
309 The eh region creation is straight-forward, but frobbing all the gotos
310 and such into shape isn't. */
312 /* The sequence into which we record all EH stuff. This will be
313 placed at the end of the function when we're all done. */
314 static gimple_seq eh_seq
;
316 /* Record whether an EH region contains something that can throw,
317 indexed by EH region number. */
318 static bitmap eh_region_may_contain_throw_map
;
320 /* The GOTO_QUEUE is an array of GIMPLE_GOTO and GIMPLE_RETURN
321 statements that are seen to escape this GIMPLE_TRY_FINALLY node.
322 The idea is to record a gimple statement for everything except for
323 the conditionals, which get their labels recorded. Since labels are
324 of type 'tree', we need this node to store both gimple and tree
325 objects. REPL_STMT is the sequence used to replace the goto/return
326 statement. CONT_STMT is used to store the statement that allows
327 the return/goto to jump to the original destination. */
329 struct goto_queue_node
333 gimple_seq repl_stmt
;
336 /* This is used when index >= 0 to indicate that stmt is a label (as
337 opposed to a goto stmt). */
341 /* State of the world while lowering. */
345 /* What's "current" while constructing the eh region tree. These
346 correspond to variables of the same name in cfun->eh, which we
347 don't have easy access to. */
348 eh_region cur_region
;
350 /* What's "current" for the purposes of __builtin_eh_pointer. For
351 a CATCH, this is the associated TRY. For an EH_FILTER, this is
352 the associated ALLOWED_EXCEPTIONS, etc. */
353 eh_region ehp_region
;
355 /* Processing of TRY_FINALLY requires a bit more state. This is
356 split out into a separate structure so that we don't have to
357 copy so much when processing other nodes. */
358 struct leh_tf_state
*tf
;
363 /* Pointer to the GIMPLE_TRY_FINALLY node under discussion. The
364 try_finally_expr is the original GIMPLE_TRY_FINALLY. We need to retain
365 this so that outside_finally_tree can reliably reference the tree used
366 in the collect_finally_tree data structures. */
367 gtry
*try_finally_expr
;
370 /* While lowering a top_p usually it is expanded into multiple statements,
371 thus we need the following field to store them. */
372 gimple_seq top_p_seq
;
374 /* The state outside this try_finally node. */
375 struct leh_state
*outer
;
377 /* The exception region created for it. */
380 /* The goto queue. */
381 struct goto_queue_node
*goto_queue
;
382 size_t goto_queue_size
;
383 size_t goto_queue_active
;
385 /* Pointer map to help in searching goto_queue when it is large. */
386 hash_map
<gimple
*, goto_queue_node
*> *goto_queue_map
;
388 /* The set of unique labels seen as entries in the goto queue. */
389 vec
<tree
> dest_array
;
391 /* A label to be added at the end of the completed transformed
392 sequence. It will be set if may_fallthru was true *at one time*,
393 though subsequent transformations may have cleared that flag. */
396 /* True if it is possible to fall out the bottom of the try block.
397 Cleared if the fallthru is converted to a goto. */
400 /* True if any entry in goto_queue is a GIMPLE_RETURN. */
403 /* True if the finally block can receive an exception edge.
404 Cleared if the exception case is handled by code duplication. */
408 static gimple_seq
lower_eh_must_not_throw (struct leh_state
*, gtry
*);
410 /* Search for STMT in the goto queue. Return the replacement,
411 or null if the statement isn't in the queue. */
413 #define LARGE_GOTO_QUEUE 20
415 static void lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*seq
);
418 find_goto_replacement (struct leh_tf_state
*tf
, treemple stmt
)
422 if (tf
->goto_queue_active
< LARGE_GOTO_QUEUE
)
424 for (i
= 0; i
< tf
->goto_queue_active
; i
++)
425 if ( tf
->goto_queue
[i
].stmt
.g
== stmt
.g
)
426 return tf
->goto_queue
[i
].repl_stmt
;
430 /* If we have a large number of entries in the goto_queue, create a
431 pointer map and use that for searching. */
433 if (!tf
->goto_queue_map
)
435 tf
->goto_queue_map
= new hash_map
<gimple
*, goto_queue_node
*>;
436 for (i
= 0; i
< tf
->goto_queue_active
; i
++)
438 bool existed
= tf
->goto_queue_map
->put (tf
->goto_queue
[i
].stmt
.g
,
440 gcc_assert (!existed
);
444 goto_queue_node
**slot
= tf
->goto_queue_map
->get (stmt
.g
);
446 return ((*slot
)->repl_stmt
);
451 /* A subroutine of replace_goto_queue_1. Handles the sub-clauses of a
452 lowered GIMPLE_COND. If, by chance, the replacement is a simple goto,
453 then we can just splat it in, otherwise we add the new stmts immediately
454 after the GIMPLE_COND and redirect. */
457 replace_goto_queue_cond_clause (tree
*tp
, struct leh_tf_state
*tf
,
458 gimple_stmt_iterator
*gsi
)
463 location_t loc
= gimple_location (gsi_stmt (*gsi
));
466 new_seq
= find_goto_replacement (tf
, temp
);
470 if (gimple_seq_singleton_p (new_seq
)
471 && gimple_code (gimple_seq_first_stmt (new_seq
)) == GIMPLE_GOTO
)
473 *tp
= gimple_goto_dest (gimple_seq_first_stmt (new_seq
));
477 label
= create_artificial_label (loc
);
478 /* Set the new label for the GIMPLE_COND */
481 gsi_insert_after (gsi
, gimple_build_label (label
), GSI_CONTINUE_LINKING
);
482 gsi_insert_seq_after (gsi
, gimple_seq_copy (new_seq
), GSI_CONTINUE_LINKING
);
485 /* The real work of replace_goto_queue. Returns with TSI updated to
486 point to the next statement. */
488 static void replace_goto_queue_stmt_list (gimple_seq
*, struct leh_tf_state
*);
491 replace_goto_queue_1 (gimple
*stmt
, struct leh_tf_state
*tf
,
492 gimple_stmt_iterator
*gsi
)
498 switch (gimple_code (stmt
))
503 seq
= find_goto_replacement (tf
, temp
);
506 gsi_insert_seq_before (gsi
, gimple_seq_copy (seq
), GSI_SAME_STMT
);
507 gsi_remove (gsi
, false);
513 replace_goto_queue_cond_clause (gimple_op_ptr (stmt
, 2), tf
, gsi
);
514 replace_goto_queue_cond_clause (gimple_op_ptr (stmt
, 3), tf
, gsi
);
518 replace_goto_queue_stmt_list (gimple_try_eval_ptr (stmt
), tf
);
519 replace_goto_queue_stmt_list (gimple_try_cleanup_ptr (stmt
), tf
);
522 replace_goto_queue_stmt_list (gimple_catch_handler_ptr (
523 as_a
<gcatch
*> (stmt
)),
526 case GIMPLE_EH_FILTER
:
527 replace_goto_queue_stmt_list (gimple_eh_filter_failure_ptr (stmt
), tf
);
531 geh_else
*eh_else_stmt
= as_a
<geh_else
*> (stmt
);
532 replace_goto_queue_stmt_list (gimple_eh_else_n_body_ptr (eh_else_stmt
),
534 replace_goto_queue_stmt_list (gimple_eh_else_e_body_ptr (eh_else_stmt
),
540 /* These won't have gotos in them. */
547 /* A subroutine of replace_goto_queue. Handles GIMPLE_SEQ. */
550 replace_goto_queue_stmt_list (gimple_seq
*seq
, struct leh_tf_state
*tf
)
552 gimple_stmt_iterator gsi
= gsi_start (*seq
);
554 while (!gsi_end_p (gsi
))
555 replace_goto_queue_1 (gsi_stmt (gsi
), tf
, &gsi
);
558 /* Replace all goto queue members. */
561 replace_goto_queue (struct leh_tf_state
*tf
)
563 if (tf
->goto_queue_active
== 0)
565 replace_goto_queue_stmt_list (&tf
->top_p_seq
, tf
);
566 replace_goto_queue_stmt_list (&eh_seq
, tf
);
569 /* Add a new record to the goto queue contained in TF. NEW_STMT is the
570 data to be added, IS_LABEL indicates whether NEW_STMT is a label or
574 record_in_goto_queue (struct leh_tf_state
*tf
,
581 struct goto_queue_node
*q
;
583 gcc_assert (!tf
->goto_queue_map
);
585 active
= tf
->goto_queue_active
;
586 size
= tf
->goto_queue_size
;
589 size
= (size
? size
* 2 : 32);
590 tf
->goto_queue_size
= size
;
592 = XRESIZEVEC (struct goto_queue_node
, tf
->goto_queue
, size
);
595 q
= &tf
->goto_queue
[active
];
596 tf
->goto_queue_active
= active
+ 1;
598 memset (q
, 0, sizeof (*q
));
601 q
->location
= location
;
602 q
->is_label
= is_label
;
605 /* Record the LABEL label in the goto queue contained in TF.
609 record_in_goto_queue_label (struct leh_tf_state
*tf
, treemple stmt
, tree label
,
613 treemple temp
, new_stmt
;
618 /* Computed and non-local gotos do not get processed. Given
619 their nature we can neither tell whether we've escaped the
620 finally block nor redirect them if we knew. */
621 if (TREE_CODE (label
) != LABEL_DECL
)
624 /* No need to record gotos that don't leave the try block. */
626 if (!outside_finally_tree (temp
, tf
->try_finally_expr
))
629 if (! tf
->dest_array
.exists ())
631 tf
->dest_array
.create (10);
632 tf
->dest_array
.quick_push (label
);
637 int n
= tf
->dest_array
.length ();
638 for (index
= 0; index
< n
; ++index
)
639 if (tf
->dest_array
[index
] == label
)
642 tf
->dest_array
.safe_push (label
);
645 /* In the case of a GOTO we want to record the destination label,
646 since with a GIMPLE_COND we have an easy access to the then/else
649 record_in_goto_queue (tf
, new_stmt
, index
, true, location
);
652 /* For any GIMPLE_GOTO or GIMPLE_RETURN, decide whether it leaves a try_finally
653 node, and if so record that fact in the goto queue associated with that
657 maybe_record_in_goto_queue (struct leh_state
*state
, gimple
*stmt
)
659 struct leh_tf_state
*tf
= state
->tf
;
665 switch (gimple_code (stmt
))
669 gcond
*cond_stmt
= as_a
<gcond
*> (stmt
);
670 new_stmt
.tp
= gimple_op_ptr (cond_stmt
, 2);
671 record_in_goto_queue_label (tf
, new_stmt
,
672 gimple_cond_true_label (cond_stmt
),
673 EXPR_LOCATION (*new_stmt
.tp
));
674 new_stmt
.tp
= gimple_op_ptr (cond_stmt
, 3);
675 record_in_goto_queue_label (tf
, new_stmt
,
676 gimple_cond_false_label (cond_stmt
),
677 EXPR_LOCATION (*new_stmt
.tp
));
682 record_in_goto_queue_label (tf
, new_stmt
, gimple_goto_dest (stmt
),
683 gimple_location (stmt
));
687 tf
->may_return
= true;
689 record_in_goto_queue (tf
, new_stmt
, -1, false, gimple_location (stmt
));
699 /* We do not process GIMPLE_SWITCHes for now. As long as the original source
700 was in fact structured, and we've not yet done jump threading, then none
701 of the labels will leave outer GIMPLE_TRY_FINALLY nodes. Verify this. */
704 verify_norecord_switch_expr (struct leh_state
*state
,
705 gswitch
*switch_expr
)
707 struct leh_tf_state
*tf
= state
->tf
;
713 n
= gimple_switch_num_labels (switch_expr
);
715 for (i
= 0; i
< n
; ++i
)
718 tree lab
= CASE_LABEL (gimple_switch_label (switch_expr
, i
));
720 gcc_assert (!outside_finally_tree (temp
, tf
->try_finally_expr
));
724 #define verify_norecord_switch_expr(state, switch_expr)
727 /* Redirect a RETURN_EXPR pointed to by Q to FINLAB. If MOD is
728 non-null, insert it before the new branch. */
731 do_return_redirection (struct goto_queue_node
*q
, tree finlab
, gimple_seq mod
)
735 /* In the case of a return, the queue node must be a gimple statement. */
736 gcc_assert (!q
->is_label
);
738 /* Note that the return value may have already been computed, e.g.,
751 should return 0, not 1. We don't have to do anything to make
752 this happens because the return value has been placed in the
753 RESULT_DECL already. */
755 q
->cont_stmt
= q
->stmt
.g
;
758 gimple_seq_add_seq (&q
->repl_stmt
, mod
);
760 x
= gimple_build_goto (finlab
);
761 gimple_set_location (x
, q
->location
);
762 gimple_seq_add_stmt (&q
->repl_stmt
, x
);
765 /* Similar, but easier, for GIMPLE_GOTO. */
768 do_goto_redirection (struct goto_queue_node
*q
, tree finlab
, gimple_seq mod
,
769 struct leh_tf_state
*tf
)
773 gcc_assert (q
->is_label
);
775 q
->cont_stmt
= gimple_build_goto (tf
->dest_array
[q
->index
]);
778 gimple_seq_add_seq (&q
->repl_stmt
, mod
);
780 x
= gimple_build_goto (finlab
);
781 gimple_set_location (x
, q
->location
);
782 gimple_seq_add_stmt (&q
->repl_stmt
, x
);
785 /* Emit a standard landing pad sequence into SEQ for REGION. */
788 emit_post_landing_pad (gimple_seq
*seq
, eh_region region
)
790 eh_landing_pad lp
= region
->landing_pads
;
794 lp
= gen_eh_landing_pad (region
);
796 lp
->post_landing_pad
= create_artificial_label (UNKNOWN_LOCATION
);
797 EH_LANDING_PAD_NR (lp
->post_landing_pad
) = lp
->index
;
799 x
= gimple_build_label (lp
->post_landing_pad
);
800 gimple_seq_add_stmt (seq
, x
);
803 /* Emit a RESX statement into SEQ for REGION. */
806 emit_resx (gimple_seq
*seq
, eh_region region
)
808 gresx
*x
= gimple_build_resx (region
->index
);
809 gimple_seq_add_stmt (seq
, x
);
811 record_stmt_eh_region (region
->outer
, x
);
814 /* Emit an EH_DISPATCH statement into SEQ for REGION. */
817 emit_eh_dispatch (gimple_seq
*seq
, eh_region region
)
819 geh_dispatch
*x
= gimple_build_eh_dispatch (region
->index
);
820 gimple_seq_add_stmt (seq
, x
);
823 /* Note that the current EH region may contain a throw, or a
824 call to a function which itself may contain a throw. */
827 note_eh_region_may_contain_throw (eh_region region
)
829 while (bitmap_set_bit (eh_region_may_contain_throw_map
, region
->index
))
831 if (region
->type
== ERT_MUST_NOT_THROW
)
833 region
= region
->outer
;
839 /* Check if REGION has been marked as containing a throw. If REGION is
840 NULL, this predicate is false. */
843 eh_region_may_contain_throw (eh_region r
)
845 return r
&& bitmap_bit_p (eh_region_may_contain_throw_map
, r
->index
);
848 /* We want to transform
849 try { body; } catch { stuff; }
859 TP is a GIMPLE_TRY node. REGION is the region whose post_landing_pad
860 should be placed before the second operand, or NULL. OVER is
861 an existing label that should be put at the exit, or NULL. */
864 frob_into_branch_around (gtry
*tp
, eh_region region
, tree over
)
867 gimple_seq cleanup
, result
;
868 location_t loc
= gimple_location (tp
);
870 cleanup
= gimple_try_cleanup (tp
);
871 result
= gimple_try_eval (tp
);
874 emit_post_landing_pad (&eh_seq
, region
);
876 if (gimple_seq_may_fallthru (cleanup
))
879 over
= create_artificial_label (loc
);
880 x
= gimple_build_goto (over
);
881 gimple_set_location (x
, loc
);
882 gimple_seq_add_stmt (&cleanup
, x
);
884 gimple_seq_add_seq (&eh_seq
, cleanup
);
888 x
= gimple_build_label (over
);
889 gimple_seq_add_stmt (&result
, x
);
894 /* A subroutine of lower_try_finally. Duplicate the tree rooted at T.
895 Make sure to record all new labels found. */
898 lower_try_finally_dup_block (gimple_seq seq
, struct leh_state
*outer_state
,
903 gimple_stmt_iterator gsi
;
905 new_seq
= copy_gimple_seq_and_replace_locals (seq
);
907 for (gsi
= gsi_start (new_seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
909 gimple
*stmt
= gsi_stmt (gsi
);
910 /* We duplicate __builtin_stack_restore at -O0 in the hope of eliminating
911 it on the EH paths. When it is not eliminated, make it transparent in
913 if (gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
914 gimple_set_location (stmt
, UNKNOWN_LOCATION
);
915 else if (LOCATION_LOCUS (gimple_location (stmt
)) == UNKNOWN_LOCATION
)
917 tree block
= gimple_block (stmt
);
918 gimple_set_location (stmt
, loc
);
919 gimple_set_block (stmt
, block
);
924 region
= outer_state
->tf
->try_finally_expr
;
925 collect_finally_tree_1 (new_seq
, region
);
930 /* A subroutine of lower_try_finally. Create a fallthru label for
931 the given try_finally state. The only tricky bit here is that
932 we have to make sure to record the label in our outer context. */
935 lower_try_finally_fallthru_label (struct leh_tf_state
*tf
)
937 tree label
= tf
->fallthru_label
;
942 label
= create_artificial_label (gimple_location (tf
->try_finally_expr
));
943 tf
->fallthru_label
= label
;
947 record_in_finally_tree (temp
, tf
->outer
->tf
->try_finally_expr
);
953 /* A subroutine of lower_try_finally. If FINALLY consits of a
954 GIMPLE_EH_ELSE node, return it. */
956 static inline geh_else
*
957 get_eh_else (gimple_seq finally
)
959 gimple
*x
= gimple_seq_first_stmt (finally
);
960 if (gimple_code (x
) == GIMPLE_EH_ELSE
)
962 gcc_assert (gimple_seq_singleton_p (finally
));
963 return as_a
<geh_else
*> (x
);
968 /* A subroutine of lower_try_finally. If the eh_protect_cleanup_actions
969 langhook returns non-null, then the language requires that the exception
970 path out of a try_finally be treated specially. To wit: the code within
971 the finally block may not itself throw an exception. We have two choices
972 here. First we can duplicate the finally block and wrap it in a
973 must_not_throw region. Second, we can generate code like
978 if (fintmp == eh_edge)
979 protect_cleanup_actions;
982 where "fintmp" is the temporary used in the switch statement generation
983 alternative considered below. For the nonce, we always choose the first
986 THIS_STATE may be null if this is a try-cleanup, not a try-finally. */
989 honor_protect_cleanup_actions (struct leh_state
*outer_state
,
990 struct leh_state
*this_state
,
991 struct leh_tf_state
*tf
)
993 gimple_seq finally
= gimple_try_cleanup (tf
->top_p
);
995 /* EH_ELSE doesn't come from user code; only compiler generated stuff.
996 It does need to be handled here, so as to separate the (different)
997 EH path from the normal path. But we should not attempt to wrap
998 it with a must-not-throw node (which indeed gets in the way). */
999 if (geh_else
*eh_else
= get_eh_else (finally
))
1001 gimple_try_set_cleanup (tf
->top_p
, gimple_eh_else_n_body (eh_else
));
1002 finally
= gimple_eh_else_e_body (eh_else
);
1004 /* Let the ELSE see the exception that's being processed. */
1005 eh_region save_ehp
= this_state
->ehp_region
;
1006 this_state
->ehp_region
= this_state
->cur_region
;
1007 lower_eh_constructs_1 (this_state
, &finally
);
1008 this_state
->ehp_region
= save_ehp
;
1012 /* First check for nothing to do. */
1013 if (lang_hooks
.eh_protect_cleanup_actions
== NULL
)
1015 tree actions
= lang_hooks
.eh_protect_cleanup_actions ();
1016 if (actions
== NULL
)
1020 finally
= lower_try_finally_dup_block (finally
, outer_state
,
1021 gimple_location (tf
->try_finally_expr
));
1023 /* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP
1024 set, the handler of the TRY_CATCH_EXPR is another cleanup which ought
1025 to be in an enclosing scope, but needs to be implemented at this level
1026 to avoid a nesting violation (see wrap_temporary_cleanups in
1027 cp/decl.c). Since it's logically at an outer level, we should call
1028 terminate before we get to it, so strip it away before adding the
1029 MUST_NOT_THROW filter. */
1030 gimple_stmt_iterator gsi
= gsi_start (finally
);
1031 gimple
*x
= gsi_stmt (gsi
);
1032 if (gimple_code (x
) == GIMPLE_TRY
1033 && gimple_try_kind (x
) == GIMPLE_TRY_CATCH
1034 && gimple_try_catch_is_cleanup (x
))
1036 gsi_insert_seq_before (&gsi
, gimple_try_eval (x
), GSI_SAME_STMT
);
1037 gsi_remove (&gsi
, false);
1040 /* Wrap the block with protect_cleanup_actions as the action. */
1041 geh_mnt
*eh_mnt
= gimple_build_eh_must_not_throw (actions
);
1042 gtry
*try_stmt
= gimple_build_try (finally
,
1043 gimple_seq_alloc_with_stmt (eh_mnt
),
1045 finally
= lower_eh_must_not_throw (outer_state
, try_stmt
);
1048 /* Drop all of this into the exception sequence. */
1049 emit_post_landing_pad (&eh_seq
, tf
->region
);
1050 gimple_seq_add_seq (&eh_seq
, finally
);
1051 if (gimple_seq_may_fallthru (finally
))
1052 emit_resx (&eh_seq
, tf
->region
);
1054 /* Having now been handled, EH isn't to be considered with
1055 the rest of the outgoing edges. */
1056 tf
->may_throw
= false;
1059 /* A subroutine of lower_try_finally. We have determined that there is
1060 no fallthru edge out of the finally block. This means that there is
1061 no outgoing edge corresponding to any incoming edge. Restructure the
1062 try_finally node for this special case. */
1065 lower_try_finally_nofallthru (struct leh_state
*state
,
1066 struct leh_tf_state
*tf
)
1072 struct goto_queue_node
*q
, *qe
;
1074 lab
= create_artificial_label (gimple_location (tf
->try_finally_expr
));
1076 /* We expect that tf->top_p is a GIMPLE_TRY. */
1077 finally
= gimple_try_cleanup (tf
->top_p
);
1078 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1080 x
= gimple_build_label (lab
);
1081 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1084 qe
= q
+ tf
->goto_queue_active
;
1087 do_return_redirection (q
, lab
, NULL
);
1089 do_goto_redirection (q
, lab
, NULL
, tf
);
1091 replace_goto_queue (tf
);
1093 /* Emit the finally block into the stream. Lower EH_ELSE at this time. */
1094 eh_else
= get_eh_else (finally
);
1097 finally
= gimple_eh_else_n_body (eh_else
);
1098 lower_eh_constructs_1 (state
, &finally
);
1099 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1103 finally
= gimple_eh_else_e_body (eh_else
);
1104 lower_eh_constructs_1 (state
, &finally
);
1106 emit_post_landing_pad (&eh_seq
, tf
->region
);
1107 gimple_seq_add_seq (&eh_seq
, finally
);
1112 lower_eh_constructs_1 (state
, &finally
);
1113 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1117 emit_post_landing_pad (&eh_seq
, tf
->region
);
1119 x
= gimple_build_goto (lab
);
1120 gimple_set_location (x
, gimple_location (tf
->try_finally_expr
));
1121 gimple_seq_add_stmt (&eh_seq
, x
);
1126 /* A subroutine of lower_try_finally. We have determined that there is
1127 exactly one destination of the finally block. Restructure the
1128 try_finally node for this special case. */
1131 lower_try_finally_onedest (struct leh_state
*state
, struct leh_tf_state
*tf
)
1133 struct goto_queue_node
*q
, *qe
;
1138 gimple_stmt_iterator gsi
;
1140 location_t loc
= gimple_location (tf
->try_finally_expr
);
1142 finally
= gimple_try_cleanup (tf
->top_p
);
1143 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1145 /* Since there's only one destination, and the destination edge can only
1146 either be EH or non-EH, that implies that all of our incoming edges
1147 are of the same type. Therefore we can lower EH_ELSE immediately. */
1148 eh_else
= get_eh_else (finally
);
1152 finally
= gimple_eh_else_e_body (eh_else
);
1154 finally
= gimple_eh_else_n_body (eh_else
);
1157 lower_eh_constructs_1 (state
, &finally
);
1159 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1161 gimple
*stmt
= gsi_stmt (gsi
);
1162 if (LOCATION_LOCUS (gimple_location (stmt
)) == UNKNOWN_LOCATION
)
1164 tree block
= gimple_block (stmt
);
1165 gimple_set_location (stmt
, gimple_location (tf
->try_finally_expr
));
1166 gimple_set_block (stmt
, block
);
1172 /* Only reachable via the exception edge. Add the given label to
1173 the head of the FINALLY block. Append a RESX at the end. */
1174 emit_post_landing_pad (&eh_seq
, tf
->region
);
1175 gimple_seq_add_seq (&eh_seq
, finally
);
1176 emit_resx (&eh_seq
, tf
->region
);
1180 if (tf
->may_fallthru
)
1182 /* Only reachable via the fallthru edge. Do nothing but let
1183 the two blocks run together; we'll fall out the bottom. */
1184 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1188 finally_label
= create_artificial_label (loc
);
1189 label_stmt
= gimple_build_label (finally_label
);
1190 gimple_seq_add_stmt (&tf
->top_p_seq
, label_stmt
);
1192 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1195 qe
= q
+ tf
->goto_queue_active
;
1199 /* Reachable by return expressions only. Redirect them. */
1201 do_return_redirection (q
, finally_label
, NULL
);
1202 replace_goto_queue (tf
);
1206 /* Reachable by goto expressions only. Redirect them. */
1208 do_goto_redirection (q
, finally_label
, NULL
, tf
);
1209 replace_goto_queue (tf
);
1211 if (tf
->dest_array
[0] == tf
->fallthru_label
)
1213 /* Reachable by goto to fallthru label only. Redirect it
1214 to the new label (already created, sadly), and do not
1215 emit the final branch out, or the fallthru label. */
1216 tf
->fallthru_label
= NULL
;
1221 /* Place the original return/goto to the original destination
1222 immediately after the finally block. */
1223 x
= tf
->goto_queue
[0].cont_stmt
;
1224 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1225 maybe_record_in_goto_queue (state
, x
);
1228 /* A subroutine of lower_try_finally. There are multiple edges incoming
1229 and outgoing from the finally block. Implement this by duplicating the
1230 finally block for every destination. */
1233 lower_try_finally_copy (struct leh_state
*state
, struct leh_tf_state
*tf
)
1236 gimple_seq new_stmt
;
1241 location_t tf_loc
= gimple_location (tf
->try_finally_expr
);
1243 finally
= gimple_try_cleanup (tf
->top_p
);
1245 /* Notice EH_ELSE, and simplify some of the remaining code
1246 by considering FINALLY to be the normal return path only. */
1247 eh_else
= get_eh_else (finally
);
1249 finally
= gimple_eh_else_n_body (eh_else
);
1251 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1254 if (tf
->may_fallthru
)
1256 seq
= lower_try_finally_dup_block (finally
, state
, tf_loc
);
1257 lower_eh_constructs_1 (state
, &seq
);
1258 gimple_seq_add_seq (&new_stmt
, seq
);
1260 tmp
= lower_try_finally_fallthru_label (tf
);
1261 x
= gimple_build_goto (tmp
);
1262 gimple_set_location (x
, tf_loc
);
1263 gimple_seq_add_stmt (&new_stmt
, x
);
1268 /* We don't need to copy the EH path of EH_ELSE,
1269 since it is only emitted once. */
1271 seq
= gimple_eh_else_e_body (eh_else
);
1273 seq
= lower_try_finally_dup_block (finally
, state
, tf_loc
);
1274 lower_eh_constructs_1 (state
, &seq
);
1276 emit_post_landing_pad (&eh_seq
, tf
->region
);
1277 gimple_seq_add_seq (&eh_seq
, seq
);
1278 emit_resx (&eh_seq
, tf
->region
);
1283 struct goto_queue_node
*q
, *qe
;
1284 int return_index
, index
;
1287 struct goto_queue_node
*q
;
1291 return_index
= tf
->dest_array
.length ();
1292 labels
= XCNEWVEC (struct labels_s
, return_index
+ 1);
1295 qe
= q
+ tf
->goto_queue_active
;
1298 index
= q
->index
< 0 ? return_index
: q
->index
;
1300 if (!labels
[index
].q
)
1301 labels
[index
].q
= q
;
1304 for (index
= 0; index
< return_index
+ 1; index
++)
1308 q
= labels
[index
].q
;
1312 lab
= labels
[index
].label
1313 = create_artificial_label (tf_loc
);
1315 if (index
== return_index
)
1316 do_return_redirection (q
, lab
, NULL
);
1318 do_goto_redirection (q
, lab
, NULL
, tf
);
1320 x
= gimple_build_label (lab
);
1321 gimple_seq_add_stmt (&new_stmt
, x
);
1323 seq
= lower_try_finally_dup_block (finally
, state
, q
->location
);
1324 lower_eh_constructs_1 (state
, &seq
);
1325 gimple_seq_add_seq (&new_stmt
, seq
);
1327 gimple_seq_add_stmt (&new_stmt
, q
->cont_stmt
);
1328 maybe_record_in_goto_queue (state
, q
->cont_stmt
);
1331 for (q
= tf
->goto_queue
; q
< qe
; q
++)
1335 index
= q
->index
< 0 ? return_index
: q
->index
;
1337 if (labels
[index
].q
== q
)
1340 lab
= labels
[index
].label
;
1342 if (index
== return_index
)
1343 do_return_redirection (q
, lab
, NULL
);
1345 do_goto_redirection (q
, lab
, NULL
, tf
);
1348 replace_goto_queue (tf
);
1352 /* Need to link new stmts after running replace_goto_queue due
1353 to not wanting to process the same goto stmts twice. */
1354 gimple_seq_add_seq (&tf
->top_p_seq
, new_stmt
);
1357 /* A subroutine of lower_try_finally. There are multiple edges incoming
1358 and outgoing from the finally block. Implement this by instrumenting
1359 each incoming edge and creating a switch statement at the end of the
1360 finally block that branches to the appropriate destination. */
1363 lower_try_finally_switch (struct leh_state
*state
, struct leh_tf_state
*tf
)
1365 struct goto_queue_node
*q
, *qe
;
1366 tree finally_tmp
, finally_label
;
1367 int return_index
, eh_index
, fallthru_index
;
1368 int nlabels
, ndests
, j
, last_case_index
;
1370 auto_vec
<tree
> case_label_vec
;
1371 gimple_seq switch_body
= NULL
;
1375 gimple
*switch_stmt
;
1377 hash_map
<tree
, gimple
*> *cont_map
= NULL
;
1378 /* The location of the TRY_FINALLY stmt. */
1379 location_t tf_loc
= gimple_location (tf
->try_finally_expr
);
1380 /* The location of the finally block. */
1381 location_t finally_loc
;
1383 finally
= gimple_try_cleanup (tf
->top_p
);
1384 eh_else
= get_eh_else (finally
);
1386 /* Mash the TRY block to the head of the chain. */
1387 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1389 /* The location of the finally is either the last stmt in the finally
1390 block or the location of the TRY_FINALLY itself. */
1391 x
= gimple_seq_last_stmt (finally
);
1392 finally_loc
= x
? gimple_location (x
) : tf_loc
;
1394 /* Prepare for switch statement generation. */
1395 nlabels
= tf
->dest_array
.length ();
1396 return_index
= nlabels
;
1397 eh_index
= return_index
+ tf
->may_return
;
1398 fallthru_index
= eh_index
+ (tf
->may_throw
&& !eh_else
);
1399 ndests
= fallthru_index
+ tf
->may_fallthru
;
1401 finally_tmp
= create_tmp_var (integer_type_node
, "finally_tmp");
1402 finally_label
= create_artificial_label (finally_loc
);
1404 /* We use vec::quick_push on case_label_vec throughout this function,
1405 since we know the size in advance and allocate precisely as muce
1407 case_label_vec
.create (ndests
);
1409 last_case_index
= 0;
1411 /* Begin inserting code for getting to the finally block. Things
1412 are done in this order to correspond to the sequence the code is
1415 if (tf
->may_fallthru
)
1417 x
= gimple_build_assign (finally_tmp
,
1418 build_int_cst (integer_type_node
,
1420 gimple_set_location (x
, finally_loc
);
1421 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1423 tmp
= build_int_cst (integer_type_node
, fallthru_index
);
1424 last_case
= build_case_label (tmp
, NULL
,
1425 create_artificial_label (finally_loc
));
1426 case_label_vec
.quick_push (last_case
);
1429 x
= gimple_build_label (CASE_LABEL (last_case
));
1430 gimple_seq_add_stmt (&switch_body
, x
);
1432 tmp
= lower_try_finally_fallthru_label (tf
);
1433 x
= gimple_build_goto (tmp
);
1434 gimple_set_location (x
, finally_loc
);
1435 gimple_seq_add_stmt (&switch_body
, x
);
1438 /* For EH_ELSE, emit the exception path (plus resx) now, then
1439 subsequently we only need consider the normal path. */
1444 finally
= gimple_eh_else_e_body (eh_else
);
1445 lower_eh_constructs_1 (state
, &finally
);
1447 emit_post_landing_pad (&eh_seq
, tf
->region
);
1448 gimple_seq_add_seq (&eh_seq
, finally
);
1449 emit_resx (&eh_seq
, tf
->region
);
1452 finally
= gimple_eh_else_n_body (eh_else
);
1454 else if (tf
->may_throw
)
1456 emit_post_landing_pad (&eh_seq
, tf
->region
);
1458 x
= gimple_build_assign (finally_tmp
,
1459 build_int_cst (integer_type_node
, eh_index
));
1460 gimple_seq_add_stmt (&eh_seq
, x
);
1462 x
= gimple_build_goto (finally_label
);
1463 gimple_set_location (x
, tf_loc
);
1464 gimple_seq_add_stmt (&eh_seq
, x
);
1466 tmp
= build_int_cst (integer_type_node
, eh_index
);
1467 last_case
= build_case_label (tmp
, NULL
,
1468 create_artificial_label (tf_loc
));
1469 case_label_vec
.quick_push (last_case
);
1472 x
= gimple_build_label (CASE_LABEL (last_case
));
1473 gimple_seq_add_stmt (&eh_seq
, x
);
1474 emit_resx (&eh_seq
, tf
->region
);
1477 x
= gimple_build_label (finally_label
);
1478 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1480 lower_eh_constructs_1 (state
, &finally
);
1481 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1483 /* Redirect each incoming goto edge. */
1485 qe
= q
+ tf
->goto_queue_active
;
1486 j
= last_case_index
+ tf
->may_return
;
1487 /* Prepare the assignments to finally_tmp that are executed upon the
1488 entrance through a particular edge. */
1491 gimple_seq mod
= NULL
;
1493 unsigned int case_index
;
1497 x
= gimple_build_assign (finally_tmp
,
1498 build_int_cst (integer_type_node
,
1500 gimple_seq_add_stmt (&mod
, x
);
1501 do_return_redirection (q
, finally_label
, mod
);
1502 switch_id
= return_index
;
1506 x
= gimple_build_assign (finally_tmp
,
1507 build_int_cst (integer_type_node
, q
->index
));
1508 gimple_seq_add_stmt (&mod
, x
);
1509 do_goto_redirection (q
, finally_label
, mod
, tf
);
1510 switch_id
= q
->index
;
1513 case_index
= j
+ q
->index
;
1514 if (case_label_vec
.length () <= case_index
|| !case_label_vec
[case_index
])
1517 tmp
= build_int_cst (integer_type_node
, switch_id
);
1518 case_lab
= build_case_label (tmp
, NULL
,
1519 create_artificial_label (tf_loc
));
1520 /* We store the cont_stmt in the pointer map, so that we can recover
1521 it in the loop below. */
1523 cont_map
= new hash_map
<tree
, gimple
*>;
1524 cont_map
->put (case_lab
, q
->cont_stmt
);
1525 case_label_vec
.quick_push (case_lab
);
1528 for (j
= last_case_index
; j
< last_case_index
+ nlabels
; j
++)
1532 last_case
= case_label_vec
[j
];
1534 gcc_assert (last_case
);
1535 gcc_assert (cont_map
);
1537 cont_stmt
= *cont_map
->get (last_case
);
1539 x
= gimple_build_label (CASE_LABEL (last_case
));
1540 gimple_seq_add_stmt (&switch_body
, x
);
1541 gimple_seq_add_stmt (&switch_body
, cont_stmt
);
1542 maybe_record_in_goto_queue (state
, cont_stmt
);
1547 replace_goto_queue (tf
);
1549 /* Make sure that the last case is the default label, as one is required.
1550 Then sort the labels, which is also required in GIMPLE. */
1551 CASE_LOW (last_case
) = NULL
;
1552 tree tem
= case_label_vec
.pop ();
1553 gcc_assert (tem
== last_case
);
1554 sort_case_labels (case_label_vec
);
1556 /* Build the switch statement, setting last_case to be the default
1558 switch_stmt
= gimple_build_switch (finally_tmp
, last_case
,
1560 gimple_set_location (switch_stmt
, finally_loc
);
1562 /* Need to link SWITCH_STMT after running replace_goto_queue
1563 due to not wanting to process the same goto stmts twice. */
1564 gimple_seq_add_stmt (&tf
->top_p_seq
, switch_stmt
);
1565 gimple_seq_add_seq (&tf
->top_p_seq
, switch_body
);
1568 /* Decide whether or not we are going to duplicate the finally block.
1569 There are several considerations.
1571 Second, we'd like to prevent egregious code growth. One way to
1572 do this is to estimate the size of the finally block, multiply
1573 that by the number of copies we'd need to make, and compare against
1574 the estimate of the size of the switch machinery we'd have to add. */
1577 decide_copy_try_finally (int ndests
, bool may_throw
, gimple_seq finally
)
1579 int f_estimate
, sw_estimate
;
1582 /* If there's an EH_ELSE involved, the exception path is separate
1583 and really doesn't come into play for this computation. */
1584 eh_else
= get_eh_else (finally
);
1587 ndests
-= may_throw
;
1588 finally
= gimple_eh_else_n_body (eh_else
);
1593 gimple_stmt_iterator gsi
;
1598 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1600 /* Duplicate __builtin_stack_restore in the hope of eliminating it
1601 on the EH paths and, consequently, useless cleanups. */
1602 gimple
*stmt
= gsi_stmt (gsi
);
1603 if (!is_gimple_debug (stmt
)
1604 && !gimple_clobber_p (stmt
)
1605 && !gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
1611 /* Finally estimate N times, plus N gotos. */
1612 f_estimate
= estimate_num_insns_seq (finally
, &eni_size_weights
);
1613 f_estimate
= (f_estimate
+ 1) * ndests
;
1615 /* Switch statement (cost 10), N variable assignments, N gotos. */
1616 sw_estimate
= 10 + 2 * ndests
;
1618 /* Optimize for size clearly wants our best guess. */
1619 if (optimize_function_for_size_p (cfun
))
1620 return f_estimate
< sw_estimate
;
1622 /* ??? These numbers are completely made up so far. */
1624 return f_estimate
< 100 || f_estimate
< sw_estimate
* 2;
1626 return f_estimate
< 40 || f_estimate
* 2 < sw_estimate
* 3;
1629 /* REG is the enclosing region for a possible cleanup region, or the region
1630 itself. Returns TRUE if such a region would be unreachable.
1632 Cleanup regions within a must-not-throw region aren't actually reachable
1633 even if there are throwing stmts within them, because the personality
1634 routine will call terminate before unwinding. */
1637 cleanup_is_dead_in (eh_region reg
)
1639 while (reg
&& reg
->type
== ERT_CLEANUP
)
1641 return (reg
&& reg
->type
== ERT_MUST_NOT_THROW
);
1644 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_FINALLY nodes
1645 to a sequence of labels and blocks, plus the exception region trees
1646 that record all the magic. This is complicated by the need to
1647 arrange for the FINALLY block to be executed on all exits. */
1650 lower_try_finally (struct leh_state
*state
, gtry
*tp
)
1652 struct leh_tf_state this_tf
;
1653 struct leh_state this_state
;
1655 gimple_seq old_eh_seq
;
1657 /* Process the try block. */
1659 memset (&this_tf
, 0, sizeof (this_tf
));
1660 this_tf
.try_finally_expr
= tp
;
1662 this_tf
.outer
= state
;
1663 if (using_eh_for_cleanups_p () && !cleanup_is_dead_in (state
->cur_region
))
1665 this_tf
.region
= gen_eh_region_cleanup (state
->cur_region
);
1666 this_state
.cur_region
= this_tf
.region
;
1670 this_tf
.region
= NULL
;
1671 this_state
.cur_region
= state
->cur_region
;
1674 this_state
.ehp_region
= state
->ehp_region
;
1675 this_state
.tf
= &this_tf
;
1677 old_eh_seq
= eh_seq
;
1680 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1682 /* Determine if the try block is escaped through the bottom. */
1683 this_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1685 /* Determine if any exceptions are possible within the try block. */
1687 this_tf
.may_throw
= eh_region_may_contain_throw (this_tf
.region
);
1688 if (this_tf
.may_throw
)
1689 honor_protect_cleanup_actions (state
, &this_state
, &this_tf
);
1691 /* Determine how many edges (still) reach the finally block. Or rather,
1692 how many destinations are reached by the finally block. Use this to
1693 determine how we process the finally block itself. */
1695 ndests
= this_tf
.dest_array
.length ();
1696 ndests
+= this_tf
.may_fallthru
;
1697 ndests
+= this_tf
.may_return
;
1698 ndests
+= this_tf
.may_throw
;
1700 /* If the FINALLY block is not reachable, dike it out. */
1703 gimple_seq_add_seq (&this_tf
.top_p_seq
, gimple_try_eval (tp
));
1704 gimple_try_set_cleanup (tp
, NULL
);
1706 /* If the finally block doesn't fall through, then any destination
1707 we might try to impose there isn't reached either. There may be
1708 some minor amount of cleanup and redirection still needed. */
1709 else if (!gimple_seq_may_fallthru (gimple_try_cleanup (tp
)))
1710 lower_try_finally_nofallthru (state
, &this_tf
);
1712 /* We can easily special-case redirection to a single destination. */
1713 else if (ndests
== 1)
1714 lower_try_finally_onedest (state
, &this_tf
);
1715 else if (decide_copy_try_finally (ndests
, this_tf
.may_throw
,
1716 gimple_try_cleanup (tp
)))
1717 lower_try_finally_copy (state
, &this_tf
);
1719 lower_try_finally_switch (state
, &this_tf
);
1721 /* If someone requested we add a label at the end of the transformed
1723 if (this_tf
.fallthru_label
)
1725 /* This must be reached only if ndests == 0. */
1726 gimple
*x
= gimple_build_label (this_tf
.fallthru_label
);
1727 gimple_seq_add_stmt (&this_tf
.top_p_seq
, x
);
1730 this_tf
.dest_array
.release ();
1731 free (this_tf
.goto_queue
);
1732 if (this_tf
.goto_queue_map
)
1733 delete this_tf
.goto_queue_map
;
1735 /* If there was an old (aka outer) eh_seq, append the current eh_seq.
1736 If there was no old eh_seq, then the append is trivially already done. */
1740 eh_seq
= old_eh_seq
;
1743 gimple_seq new_eh_seq
= eh_seq
;
1744 eh_seq
= old_eh_seq
;
1745 gimple_seq_add_seq (&eh_seq
, new_eh_seq
);
1749 return this_tf
.top_p_seq
;
1752 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_CATCH with a
1753 list of GIMPLE_CATCH to a sequence of labels and blocks, plus the
1754 exception region trees that records all the magic. */
1757 lower_catch (struct leh_state
*state
, gtry
*tp
)
1759 eh_region try_region
= NULL
;
1760 struct leh_state this_state
= *state
;
1761 gimple_stmt_iterator gsi
;
1763 gimple_seq new_seq
, cleanup
;
1765 location_t try_catch_loc
= gimple_location (tp
);
1767 if (flag_exceptions
)
1769 try_region
= gen_eh_region_try (state
->cur_region
);
1770 this_state
.cur_region
= try_region
;
1773 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1775 if (!eh_region_may_contain_throw (try_region
))
1776 return gimple_try_eval (tp
);
1779 emit_eh_dispatch (&new_seq
, try_region
);
1780 emit_resx (&new_seq
, try_region
);
1782 this_state
.cur_region
= state
->cur_region
;
1783 this_state
.ehp_region
= try_region
;
1785 /* Add eh_seq from lowering EH in the cleanup sequence after the cleanup
1786 itself, so that e.g. for coverage purposes the nested cleanups don't
1787 appear before the cleanup body. See PR64634 for details. */
1788 gimple_seq old_eh_seq
= eh_seq
;
1792 cleanup
= gimple_try_cleanup (tp
);
1793 for (gsi
= gsi_start (cleanup
);
1801 catch_stmt
= as_a
<gcatch
*> (gsi_stmt (gsi
));
1802 c
= gen_eh_region_catch (try_region
, gimple_catch_types (catch_stmt
));
1804 handler
= gimple_catch_handler (catch_stmt
);
1805 lower_eh_constructs_1 (&this_state
, &handler
);
1807 c
->label
= create_artificial_label (UNKNOWN_LOCATION
);
1808 x
= gimple_build_label (c
->label
);
1809 gimple_seq_add_stmt (&new_seq
, x
);
1811 gimple_seq_add_seq (&new_seq
, handler
);
1813 if (gimple_seq_may_fallthru (new_seq
))
1816 out_label
= create_artificial_label (try_catch_loc
);
1818 x
= gimple_build_goto (out_label
);
1819 gimple_seq_add_stmt (&new_seq
, x
);
1825 gimple_try_set_cleanup (tp
, new_seq
);
1827 gimple_seq new_eh_seq
= eh_seq
;
1828 eh_seq
= old_eh_seq
;
1829 gimple_seq ret_seq
= frob_into_branch_around (tp
, try_region
, out_label
);
1830 gimple_seq_add_seq (&eh_seq
, new_eh_seq
);
1834 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with a
1835 GIMPLE_EH_FILTER to a sequence of labels and blocks, plus the exception
1836 region trees that record all the magic. */
1839 lower_eh_filter (struct leh_state
*state
, gtry
*tp
)
1841 struct leh_state this_state
= *state
;
1842 eh_region this_region
= NULL
;
1846 inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1848 if (flag_exceptions
)
1850 this_region
= gen_eh_region_allowed (state
->cur_region
,
1851 gimple_eh_filter_types (inner
));
1852 this_state
.cur_region
= this_region
;
1855 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1857 if (!eh_region_may_contain_throw (this_region
))
1858 return gimple_try_eval (tp
);
1861 this_state
.cur_region
= state
->cur_region
;
1862 this_state
.ehp_region
= this_region
;
1864 emit_eh_dispatch (&new_seq
, this_region
);
1865 emit_resx (&new_seq
, this_region
);
1867 this_region
->u
.allowed
.label
= create_artificial_label (UNKNOWN_LOCATION
);
1868 x
= gimple_build_label (this_region
->u
.allowed
.label
);
1869 gimple_seq_add_stmt (&new_seq
, x
);
1871 lower_eh_constructs_1 (&this_state
, gimple_eh_filter_failure_ptr (inner
));
1872 gimple_seq_add_seq (&new_seq
, gimple_eh_filter_failure (inner
));
1874 gimple_try_set_cleanup (tp
, new_seq
);
1876 return frob_into_branch_around (tp
, this_region
, NULL
);
1879 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with
1880 an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks,
1881 plus the exception region trees that record all the magic. */
1884 lower_eh_must_not_throw (struct leh_state
*state
, gtry
*tp
)
1886 struct leh_state this_state
= *state
;
1888 if (flag_exceptions
)
1890 gimple
*inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1891 eh_region this_region
;
1893 this_region
= gen_eh_region_must_not_throw (state
->cur_region
);
1894 this_region
->u
.must_not_throw
.failure_decl
1895 = gimple_eh_must_not_throw_fndecl (
1896 as_a
<geh_mnt
*> (inner
));
1897 this_region
->u
.must_not_throw
.failure_loc
1898 = LOCATION_LOCUS (gimple_location (tp
));
1900 /* In order to get mangling applied to this decl, we must mark it
1901 used now. Otherwise, pass_ipa_free_lang_data won't think it
1903 TREE_USED (this_region
->u
.must_not_throw
.failure_decl
) = 1;
1905 this_state
.cur_region
= this_region
;
1908 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1910 return gimple_try_eval (tp
);
1913 /* Implement a cleanup expression. This is similar to try-finally,
1914 except that we only execute the cleanup block for exception edges. */
1917 lower_cleanup (struct leh_state
*state
, gtry
*tp
)
1919 struct leh_state this_state
= *state
;
1920 eh_region this_region
= NULL
;
1921 struct leh_tf_state fake_tf
;
1923 bool cleanup_dead
= cleanup_is_dead_in (state
->cur_region
);
1925 if (flag_exceptions
&& !cleanup_dead
)
1927 this_region
= gen_eh_region_cleanup (state
->cur_region
);
1928 this_state
.cur_region
= this_region
;
1931 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1933 if (cleanup_dead
|| !eh_region_may_contain_throw (this_region
))
1934 return gimple_try_eval (tp
);
1936 /* Build enough of a try-finally state so that we can reuse
1937 honor_protect_cleanup_actions. */
1938 memset (&fake_tf
, 0, sizeof (fake_tf
));
1939 fake_tf
.top_p
= fake_tf
.try_finally_expr
= tp
;
1940 fake_tf
.outer
= state
;
1941 fake_tf
.region
= this_region
;
1942 fake_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1943 fake_tf
.may_throw
= true;
1945 honor_protect_cleanup_actions (state
, NULL
, &fake_tf
);
1947 if (fake_tf
.may_throw
)
1949 /* In this case honor_protect_cleanup_actions had nothing to do,
1950 and we should process this normally. */
1951 lower_eh_constructs_1 (state
, gimple_try_cleanup_ptr (tp
));
1952 result
= frob_into_branch_around (tp
, this_region
,
1953 fake_tf
.fallthru_label
);
1957 /* In this case honor_protect_cleanup_actions did nearly all of
1958 the work. All we have left is to append the fallthru_label. */
1960 result
= gimple_try_eval (tp
);
1961 if (fake_tf
.fallthru_label
)
1963 gimple
*x
= gimple_build_label (fake_tf
.fallthru_label
);
1964 gimple_seq_add_stmt (&result
, x
);
1970 /* Main loop for lowering eh constructs. Also moves gsi to the next
1974 lower_eh_constructs_2 (struct leh_state
*state
, gimple_stmt_iterator
*gsi
)
1978 gimple
*stmt
= gsi_stmt (*gsi
);
1980 switch (gimple_code (stmt
))
1984 tree fndecl
= gimple_call_fndecl (stmt
);
1987 if (fndecl
&& fndecl_built_in_p (fndecl
, BUILT_IN_NORMAL
))
1988 switch (DECL_FUNCTION_CODE (fndecl
))
1990 case BUILT_IN_EH_POINTER
:
1991 /* The front end may have generated a call to
1992 __builtin_eh_pointer (0) within a catch region. Replace
1993 this zero argument with the current catch region number. */
1994 if (state
->ehp_region
)
1996 tree nr
= build_int_cst (integer_type_node
,
1997 state
->ehp_region
->index
);
1998 gimple_call_set_arg (stmt
, 0, nr
);
2002 /* The user has dome something silly. Remove it. */
2003 rhs
= null_pointer_node
;
2008 case BUILT_IN_EH_FILTER
:
2009 /* ??? This should never appear, but since it's a builtin it
2010 is accessible to abuse by users. Just remove it and
2011 replace the use with the arbitrary value zero. */
2012 rhs
= build_int_cst (TREE_TYPE (TREE_TYPE (fndecl
)), 0);
2014 lhs
= gimple_call_lhs (stmt
);
2015 x
= gimple_build_assign (lhs
, rhs
);
2016 gsi_insert_before (gsi
, x
, GSI_SAME_STMT
);
2019 case BUILT_IN_EH_COPY_VALUES
:
2020 /* Likewise this should not appear. Remove it. */
2021 gsi_remove (gsi
, true);
2031 /* If the stmt can throw, use a new temporary for the assignment
2032 to a LHS. This makes sure the old value of the LHS is
2033 available on the EH edge. Only do so for statements that
2034 potentially fall through (no noreturn calls e.g.), otherwise
2035 this new assignment might create fake fallthru regions. */
2036 if (stmt_could_throw_p (cfun
, stmt
)
2037 && gimple_has_lhs (stmt
)
2038 && gimple_stmt_may_fallthru (stmt
)
2039 && !tree_could_throw_p (gimple_get_lhs (stmt
))
2040 && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt
))))
2042 tree lhs
= gimple_get_lhs (stmt
);
2043 tree tmp
= create_tmp_var (TREE_TYPE (lhs
));
2044 gimple
*s
= gimple_build_assign (lhs
, tmp
);
2045 gimple_set_location (s
, gimple_location (stmt
));
2046 gimple_set_block (s
, gimple_block (stmt
));
2047 gimple_set_lhs (stmt
, tmp
);
2048 if (TREE_CODE (TREE_TYPE (tmp
)) == COMPLEX_TYPE
2049 || TREE_CODE (TREE_TYPE (tmp
)) == VECTOR_TYPE
)
2050 DECL_GIMPLE_REG_P (tmp
) = 1;
2051 gsi_insert_after (gsi
, s
, GSI_SAME_STMT
);
2053 /* Look for things that can throw exceptions, and record them. */
2054 if (state
->cur_region
&& stmt_could_throw_p (cfun
, stmt
))
2056 record_stmt_eh_region (state
->cur_region
, stmt
);
2057 note_eh_region_may_contain_throw (state
->cur_region
);
2064 maybe_record_in_goto_queue (state
, stmt
);
2068 verify_norecord_switch_expr (state
, as_a
<gswitch
*> (stmt
));
2073 gtry
*try_stmt
= as_a
<gtry
*> (stmt
);
2074 if (gimple_try_kind (try_stmt
) == GIMPLE_TRY_FINALLY
)
2075 replace
= lower_try_finally (state
, try_stmt
);
2078 x
= gimple_seq_first_stmt (gimple_try_cleanup (try_stmt
));
2081 replace
= gimple_try_eval (try_stmt
);
2082 lower_eh_constructs_1 (state
, &replace
);
2085 switch (gimple_code (x
))
2088 replace
= lower_catch (state
, try_stmt
);
2090 case GIMPLE_EH_FILTER
:
2091 replace
= lower_eh_filter (state
, try_stmt
);
2093 case GIMPLE_EH_MUST_NOT_THROW
:
2094 replace
= lower_eh_must_not_throw (state
, try_stmt
);
2096 case GIMPLE_EH_ELSE
:
2097 /* This code is only valid with GIMPLE_TRY_FINALLY. */
2100 replace
= lower_cleanup (state
, try_stmt
);
2106 /* Remove the old stmt and insert the transformed sequence
2108 gsi_insert_seq_before (gsi
, replace
, GSI_SAME_STMT
);
2109 gsi_remove (gsi
, true);
2111 /* Return since we don't want gsi_next () */
2114 case GIMPLE_EH_ELSE
:
2115 /* We should be eliminating this in lower_try_finally et al. */
2119 /* A type, a decl, or some kind of statement that we're not
2120 interested in. Don't walk them. */
2127 /* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */
2130 lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*pseq
)
2132 gimple_stmt_iterator gsi
;
2133 for (gsi
= gsi_start (*pseq
); !gsi_end_p (gsi
);)
2134 lower_eh_constructs_2 (state
, &gsi
);
2139 const pass_data pass_data_lower_eh
=
2141 GIMPLE_PASS
, /* type */
2143 OPTGROUP_NONE
, /* optinfo_flags */
2144 TV_TREE_EH
, /* tv_id */
2145 PROP_gimple_lcf
, /* properties_required */
2146 PROP_gimple_leh
, /* properties_provided */
2147 0, /* properties_destroyed */
2148 0, /* todo_flags_start */
2149 0, /* todo_flags_finish */
2152 class pass_lower_eh
: public gimple_opt_pass
2155 pass_lower_eh (gcc::context
*ctxt
)
2156 : gimple_opt_pass (pass_data_lower_eh
, ctxt
)
2159 /* opt_pass methods: */
2160 virtual unsigned int execute (function
*);
2162 }; // class pass_lower_eh
2165 pass_lower_eh::execute (function
*fun
)
2167 struct leh_state null_state
;
2170 bodyp
= gimple_body (current_function_decl
);
2174 finally_tree
= new hash_table
<finally_tree_hasher
> (31);
2175 eh_region_may_contain_throw_map
= BITMAP_ALLOC (NULL
);
2176 memset (&null_state
, 0, sizeof (null_state
));
2178 collect_finally_tree_1 (bodyp
, NULL
);
2179 lower_eh_constructs_1 (&null_state
, &bodyp
);
2180 gimple_set_body (current_function_decl
, bodyp
);
2182 /* We assume there's a return statement, or something, at the end of
2183 the function, and thus ploping the EH sequence afterward won't
2185 gcc_assert (!gimple_seq_may_fallthru (bodyp
));
2186 gimple_seq_add_seq (&bodyp
, eh_seq
);
2188 /* We assume that since BODYP already existed, adding EH_SEQ to it
2189 didn't change its value, and we don't have to re-set the function. */
2190 gcc_assert (bodyp
== gimple_body (current_function_decl
));
2192 delete finally_tree
;
2193 finally_tree
= NULL
;
2194 BITMAP_FREE (eh_region_may_contain_throw_map
);
2197 /* If this function needs a language specific EH personality routine
2198 and the frontend didn't already set one do so now. */
2199 if (function_needs_eh_personality (fun
) == eh_personality_lang
2200 && !DECL_FUNCTION_PERSONALITY (current_function_decl
))
2201 DECL_FUNCTION_PERSONALITY (current_function_decl
)
2202 = lang_hooks
.eh_personality ();
2210 make_pass_lower_eh (gcc::context
*ctxt
)
2212 return new pass_lower_eh (ctxt
);
2215 /* Create the multiple edges from an EH_DISPATCH statement to all of
2216 the possible handlers for its EH region. Return true if there's
2217 no fallthru edge; false if there is. */
2220 make_eh_dispatch_edges (geh_dispatch
*stmt
)
2224 basic_block src
, dst
;
2226 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2227 src
= gimple_bb (stmt
);
2232 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2234 dst
= label_to_block (cfun
, c
->label
);
2235 make_edge (src
, dst
, 0);
2237 /* A catch-all handler doesn't have a fallthru. */
2238 if (c
->type_list
== NULL
)
2243 case ERT_ALLOWED_EXCEPTIONS
:
2244 dst
= label_to_block (cfun
, r
->u
.allowed
.label
);
2245 make_edge (src
, dst
, 0);
2255 /* Create the single EH edge from STMT to its nearest landing pad,
2256 if there is such a landing pad within the current function. */
2259 make_eh_edges (gimple
*stmt
)
2261 basic_block src
, dst
;
2265 lp_nr
= lookup_stmt_eh_lp (stmt
);
2269 lp
= get_eh_landing_pad_from_number (lp_nr
);
2270 gcc_assert (lp
!= NULL
);
2272 src
= gimple_bb (stmt
);
2273 dst
= label_to_block (cfun
, lp
->post_landing_pad
);
2274 make_edge (src
, dst
, EDGE_EH
);
2277 /* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
2278 do not actually perform the final edge redirection.
2280 CHANGE_REGION is true when we're being called from cleanup_empty_eh and
2281 we intend to change the destination EH region as well; this means
2282 EH_LANDING_PAD_NR must already be set on the destination block label.
2283 If false, we're being called from generic cfg manipulation code and we
2284 should preserve our place within the region tree. */
2287 redirect_eh_edge_1 (edge edge_in
, basic_block new_bb
, bool change_region
)
2289 eh_landing_pad old_lp
, new_lp
;
2292 int old_lp_nr
, new_lp_nr
;
2293 tree old_label
, new_label
;
2297 old_bb
= edge_in
->dest
;
2298 old_label
= gimple_block_label (old_bb
);
2299 old_lp_nr
= EH_LANDING_PAD_NR (old_label
);
2300 gcc_assert (old_lp_nr
> 0);
2301 old_lp
= get_eh_landing_pad_from_number (old_lp_nr
);
2303 throw_stmt
= last_stmt (edge_in
->src
);
2304 gcc_assert (lookup_stmt_eh_lp (throw_stmt
) == old_lp_nr
);
2306 new_label
= gimple_block_label (new_bb
);
2308 /* Look for an existing region that might be using NEW_BB already. */
2309 new_lp_nr
= EH_LANDING_PAD_NR (new_label
);
2312 new_lp
= get_eh_landing_pad_from_number (new_lp_nr
);
2313 gcc_assert (new_lp
);
2315 /* Unless CHANGE_REGION is true, the new and old landing pad
2316 had better be associated with the same EH region. */
2317 gcc_assert (change_region
|| new_lp
->region
== old_lp
->region
);
2322 gcc_assert (!change_region
);
2325 /* Notice when we redirect the last EH edge away from OLD_BB. */
2326 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
2327 if (e
!= edge_in
&& (e
->flags
& EDGE_EH
))
2332 /* NEW_LP already exists. If there are still edges into OLD_LP,
2333 there's nothing to do with the EH tree. If there are no more
2334 edges into OLD_LP, then we want to remove OLD_LP as it is unused.
2335 If CHANGE_REGION is true, then our caller is expecting to remove
2337 if (e
== NULL
&& !change_region
)
2338 remove_eh_landing_pad (old_lp
);
2342 /* No correct landing pad exists. If there are no more edges
2343 into OLD_LP, then we can simply re-use the existing landing pad.
2344 Otherwise, we have to create a new landing pad. */
2347 EH_LANDING_PAD_NR (old_lp
->post_landing_pad
) = 0;
2351 new_lp
= gen_eh_landing_pad (old_lp
->region
);
2352 new_lp
->post_landing_pad
= new_label
;
2353 EH_LANDING_PAD_NR (new_label
) = new_lp
->index
;
2356 /* Maybe move the throwing statement to the new region. */
2357 if (old_lp
!= new_lp
)
2359 remove_stmt_from_eh_lp (throw_stmt
);
2360 add_stmt_to_eh_lp (throw_stmt
, new_lp
->index
);
2364 /* Redirect EH edge E to NEW_BB. */
2367 redirect_eh_edge (edge edge_in
, basic_block new_bb
)
2369 redirect_eh_edge_1 (edge_in
, new_bb
, false);
2370 return ssa_redirect_edge (edge_in
, new_bb
);
2373 /* This is a subroutine of gimple_redirect_edge_and_branch. Update the
2374 labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
2375 The actual edge update will happen in the caller. */
2378 redirect_eh_dispatch_edge (geh_dispatch
*stmt
, edge e
, basic_block new_bb
)
2380 tree new_lab
= gimple_block_label (new_bb
);
2381 bool any_changed
= false;
2386 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2390 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2392 old_bb
= label_to_block (cfun
, c
->label
);
2393 if (old_bb
== e
->dest
)
2401 case ERT_ALLOWED_EXCEPTIONS
:
2402 old_bb
= label_to_block (cfun
, r
->u
.allowed
.label
);
2403 gcc_assert (old_bb
== e
->dest
);
2404 r
->u
.allowed
.label
= new_lab
;
2412 gcc_assert (any_changed
);
2415 /* Helper function for operation_could_trap_p and stmt_could_throw_p. */
2418 operation_could_trap_helper_p (enum tree_code op
,
2429 case TRUNC_DIV_EXPR
:
2431 case FLOOR_DIV_EXPR
:
2432 case ROUND_DIV_EXPR
:
2433 case EXACT_DIV_EXPR
:
2435 case FLOOR_MOD_EXPR
:
2436 case ROUND_MOD_EXPR
:
2437 case TRUNC_MOD_EXPR
:
2442 return flag_trapping_math
;
2443 if (!TREE_CONSTANT (divisor
) || integer_zerop (divisor
))
2452 /* Some floating point comparisons may trap. */
2457 case UNORDERED_EXPR
:
2469 /* These operations don't trap with floating point. */
2475 /* ABSU_EXPR never traps. */
2481 /* Any floating arithmetic may trap. */
2482 if (fp_operation
&& flag_trapping_math
)
2490 /* Constructing an object cannot trap. */
2494 /* Any floating arithmetic may trap. */
2495 if (fp_operation
&& flag_trapping_math
)
2503 /* Return true if operation OP may trap. FP_OPERATION is true if OP is applied
2504 on floating-point values. HONOR_TRAPV is true if OP is applied on integer
2505 type operands that may trap. If OP is a division operator, DIVISOR contains
2506 the value of the divisor. */
2509 operation_could_trap_p (enum tree_code op
, bool fp_operation
, bool honor_trapv
,
2512 bool honor_nans
= (fp_operation
&& flag_trapping_math
2513 && !flag_finite_math_only
);
2514 bool honor_snans
= fp_operation
&& flag_signaling_nans
!= 0;
2517 if (TREE_CODE_CLASS (op
) != tcc_comparison
2518 && TREE_CODE_CLASS (op
) != tcc_unary
2519 && TREE_CODE_CLASS (op
) != tcc_binary
)
2522 return operation_could_trap_helper_p (op
, fp_operation
, honor_trapv
,
2523 honor_nans
, honor_snans
, divisor
,
2528 /* Returns true if it is possible to prove that the index of
2529 an array access REF (an ARRAY_REF expression) falls into the
2533 in_array_bounds_p (tree ref
)
2535 tree idx
= TREE_OPERAND (ref
, 1);
2538 if (TREE_CODE (idx
) != INTEGER_CST
)
2541 min
= array_ref_low_bound (ref
);
2542 max
= array_ref_up_bound (ref
);
2545 || TREE_CODE (min
) != INTEGER_CST
2546 || TREE_CODE (max
) != INTEGER_CST
)
2549 if (tree_int_cst_lt (idx
, min
)
2550 || tree_int_cst_lt (max
, idx
))
2556 /* Returns true if it is possible to prove that the range of
2557 an array access REF (an ARRAY_RANGE_REF expression) falls
2558 into the array bounds. */
2561 range_in_array_bounds_p (tree ref
)
2563 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (ref
));
2564 tree range_min
, range_max
, min
, max
;
2566 range_min
= TYPE_MIN_VALUE (domain_type
);
2567 range_max
= TYPE_MAX_VALUE (domain_type
);
2570 || TREE_CODE (range_min
) != INTEGER_CST
2571 || TREE_CODE (range_max
) != INTEGER_CST
)
2574 min
= array_ref_low_bound (ref
);
2575 max
= array_ref_up_bound (ref
);
2578 || TREE_CODE (min
) != INTEGER_CST
2579 || TREE_CODE (max
) != INTEGER_CST
)
2582 if (tree_int_cst_lt (range_min
, min
)
2583 || tree_int_cst_lt (max
, range_max
))
2589 /* Return true if EXPR can trap, as in dereferencing an invalid pointer
2590 location or floating point arithmetic. C.f. the rtl version, may_trap_p.
2591 This routine expects only GIMPLE lhs or rhs input. */
2594 tree_could_trap_p (tree expr
)
2596 enum tree_code code
;
2597 bool fp_operation
= false;
2598 bool honor_trapv
= false;
2599 tree t
, base
, div
= NULL_TREE
;
2604 code
= TREE_CODE (expr
);
2605 t
= TREE_TYPE (expr
);
2609 if (COMPARISON_CLASS_P (expr
))
2610 fp_operation
= FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 0)));
2612 fp_operation
= FLOAT_TYPE_P (t
);
2613 honor_trapv
= INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
);
2616 if (TREE_CODE_CLASS (code
) == tcc_binary
)
2617 div
= TREE_OPERAND (expr
, 1);
2618 if (operation_could_trap_p (code
, fp_operation
, honor_trapv
, div
))
2628 case VIEW_CONVERT_EXPR
:
2629 case WITH_SIZE_EXPR
:
2630 expr
= TREE_OPERAND (expr
, 0);
2631 code
= TREE_CODE (expr
);
2634 case ARRAY_RANGE_REF
:
2635 base
= TREE_OPERAND (expr
, 0);
2636 if (tree_could_trap_p (base
))
2638 if (TREE_THIS_NOTRAP (expr
))
2640 return !range_in_array_bounds_p (expr
);
2643 base
= TREE_OPERAND (expr
, 0);
2644 if (tree_could_trap_p (base
))
2646 if (TREE_THIS_NOTRAP (expr
))
2648 return !in_array_bounds_p (expr
);
2650 case TARGET_MEM_REF
:
2652 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
2653 && tree_could_trap_p (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
2655 if (TREE_THIS_NOTRAP (expr
))
2657 /* We cannot prove that the access is in-bounds when we have
2658 variable-index TARGET_MEM_REFs. */
2659 if (code
== TARGET_MEM_REF
2660 && (TMR_INDEX (expr
) || TMR_INDEX2 (expr
)))
2662 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
)
2664 tree base
= TREE_OPERAND (TREE_OPERAND (expr
, 0), 0);
2665 poly_offset_int off
= mem_ref_offset (expr
);
2666 if (maybe_lt (off
, 0))
2668 if (TREE_CODE (base
) == STRING_CST
)
2669 return maybe_le (TREE_STRING_LENGTH (base
), off
);
2670 tree size
= DECL_SIZE_UNIT (base
);
2671 if (size
== NULL_TREE
2672 || !poly_int_tree_p (size
)
2673 || maybe_le (wi::to_poly_offset (size
), off
))
2675 /* Now we are sure the first byte of the access is inside
2682 return !TREE_THIS_NOTRAP (expr
);
2685 return TREE_THIS_VOLATILE (expr
);
2688 t
= get_callee_fndecl (expr
);
2689 /* Assume that calls to weak functions may trap. */
2690 if (!t
|| !DECL_P (t
))
2693 return tree_could_trap_p (t
);
2697 /* Assume that accesses to weak functions may trap, unless we know
2698 they are certainly defined in current TU or in some other
2700 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
) && DECL_EXTERNAL (expr
))
2702 cgraph_node
*node
= cgraph_node::get (expr
);
2704 node
= node
->function_symbol ();
2705 return !(node
&& node
->in_other_partition
);
2710 /* Assume that accesses to weak vars may trap, unless we know
2711 they are certainly defined in current TU or in some other
2713 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
) && DECL_EXTERNAL (expr
))
2715 varpool_node
*node
= varpool_node::get (expr
);
2717 node
= node
->ultimate_alias_target ();
2718 return !(node
&& node
->in_other_partition
);
2727 /* Return non-NULL if there is an integer operation with trapping overflow
2728 we can rewrite into non-trapping. Called via walk_tree from
2729 rewrite_to_non_trapping_overflow. */
2732 find_trapping_overflow (tree
*tp
, int *walk_subtrees
, void *data
)
2735 && ANY_INTEGRAL_TYPE_P (TREE_TYPE (*tp
))
2736 && !operation_no_trapping_overflow (TREE_TYPE (*tp
), TREE_CODE (*tp
)))
2738 if (IS_TYPE_OR_DECL_P (*tp
)
2739 || (TREE_CODE (*tp
) == SAVE_EXPR
&& data
== NULL
))
2744 /* Rewrite selected operations into unsigned arithmetics, so that they
2745 don't trap on overflow. */
2748 replace_trapping_overflow (tree
*tp
, int *walk_subtrees
, void *data
)
2750 if (find_trapping_overflow (tp
, walk_subtrees
, data
))
2752 tree type
= TREE_TYPE (*tp
);
2753 tree utype
= unsigned_type_for (type
);
2755 int len
= TREE_OPERAND_LENGTH (*tp
);
2756 for (int i
= 0; i
< len
; ++i
)
2757 walk_tree (&TREE_OPERAND (*tp
, i
), replace_trapping_overflow
,
2758 data
, (hash_set
<tree
> *) data
);
2760 if (TREE_CODE (*tp
) == ABS_EXPR
)
2762 TREE_SET_CODE (*tp
, ABSU_EXPR
);
2763 TREE_TYPE (*tp
) = utype
;
2764 *tp
= fold_convert (type
, *tp
);
2768 TREE_TYPE (*tp
) = utype
;
2769 len
= TREE_OPERAND_LENGTH (*tp
);
2770 for (int i
= 0; i
< len
; ++i
)
2771 TREE_OPERAND (*tp
, i
)
2772 = fold_convert (utype
, TREE_OPERAND (*tp
, i
));
2773 *tp
= fold_convert (type
, *tp
);
2779 /* If any subexpression of EXPR can trap due to -ftrapv, rewrite it
2780 using unsigned arithmetics to avoid traps in it. */
2783 rewrite_to_non_trapping_overflow (tree expr
)
2787 hash_set
<tree
> pset
;
2788 if (!walk_tree (&expr
, find_trapping_overflow
, &pset
, &pset
))
2790 expr
= unshare_expr (expr
);
2792 walk_tree (&expr
, replace_trapping_overflow
, &pset
, &pset
);
2796 /* Helper for stmt_could_throw_p. Return true if STMT (assumed to be a
2797 an assignment or a conditional) may throw. */
2800 stmt_could_throw_1_p (gassign
*stmt
)
2802 enum tree_code code
= gimple_assign_rhs_code (stmt
);
2803 bool honor_nans
= false;
2804 bool honor_snans
= false;
2805 bool fp_operation
= false;
2806 bool honor_trapv
= false;
2811 if (TREE_CODE_CLASS (code
) == tcc_comparison
2812 || TREE_CODE_CLASS (code
) == tcc_unary
2813 || TREE_CODE_CLASS (code
) == tcc_binary
)
2815 if (TREE_CODE_CLASS (code
) == tcc_comparison
)
2816 t
= TREE_TYPE (gimple_assign_rhs1 (stmt
));
2818 t
= gimple_expr_type (stmt
);
2819 fp_operation
= FLOAT_TYPE_P (t
);
2822 honor_nans
= flag_trapping_math
&& !flag_finite_math_only
;
2823 honor_snans
= flag_signaling_nans
!= 0;
2825 else if (INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
))
2829 /* First check the LHS. */
2830 if (tree_could_trap_p (gimple_assign_lhs (stmt
)))
2833 /* Check if the main expression may trap. */
2834 ret
= operation_could_trap_helper_p (code
, fp_operation
, honor_trapv
,
2835 honor_nans
, honor_snans
,
2836 gimple_assign_rhs2 (stmt
),
2841 /* If the expression does not trap, see if any of the individual operands may
2843 for (i
= 1; i
< gimple_num_ops (stmt
); i
++)
2844 if (tree_could_trap_p (gimple_op (stmt
, i
)))
2851 /* Return true if statement STMT within FUN could throw an exception. */
2854 stmt_could_throw_p (function
*fun
, gimple
*stmt
)
2856 if (!flag_exceptions
)
2859 /* The only statements that can throw an exception are assignments,
2860 conditionals, calls, resx, and asms. */
2861 switch (gimple_code (stmt
))
2867 return !gimple_call_nothrow_p (as_a
<gcall
*> (stmt
));
2871 if (fun
&& !fun
->can_throw_non_call_exceptions
)
2873 gcond
*cond
= as_a
<gcond
*> (stmt
);
2874 tree lhs
= gimple_cond_lhs (cond
);
2875 return operation_could_trap_p (gimple_cond_code (cond
),
2876 FLOAT_TYPE_P (TREE_TYPE (lhs
)),
2881 if ((fun
&& !fun
->can_throw_non_call_exceptions
)
2882 || gimple_clobber_p (stmt
))
2884 return stmt_could_throw_1_p (as_a
<gassign
*> (stmt
));
2887 if (fun
&& !fun
->can_throw_non_call_exceptions
)
2889 return gimple_asm_volatile_p (as_a
<gasm
*> (stmt
));
2897 /* Return true if expression T could throw an exception. */
2900 tree_could_throw_p (tree t
)
2902 if (!flag_exceptions
)
2904 if (TREE_CODE (t
) == MODIFY_EXPR
)
2906 if (cfun
->can_throw_non_call_exceptions
2907 && tree_could_trap_p (TREE_OPERAND (t
, 0)))
2909 t
= TREE_OPERAND (t
, 1);
2912 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
2913 t
= TREE_OPERAND (t
, 0);
2914 if (TREE_CODE (t
) == CALL_EXPR
)
2915 return (call_expr_flags (t
) & ECF_NOTHROW
) == 0;
2916 if (cfun
->can_throw_non_call_exceptions
)
2917 return tree_could_trap_p (t
);
2921 /* Return true if STMT can throw an exception that is not caught within its
2922 function FUN. FUN can be NULL but the function is extra conservative
2926 stmt_can_throw_external (function
*fun
, gimple
*stmt
)
2930 if (!stmt_could_throw_p (fun
, stmt
))
2935 lp_nr
= lookup_stmt_eh_lp_fn (fun
, stmt
);
2939 /* Return true if STMT can throw an exception that is caught within its
2943 stmt_can_throw_internal (function
*fun
, gimple
*stmt
)
2947 gcc_checking_assert (fun
);
2948 if (!stmt_could_throw_p (fun
, stmt
))
2951 lp_nr
= lookup_stmt_eh_lp_fn (fun
, stmt
);
2955 /* Given a statement STMT in IFUN, if STMT can no longer throw, then
2956 remove any entry it might have from the EH table. Return true if
2957 any change was made. */
2960 maybe_clean_eh_stmt_fn (struct function
*ifun
, gimple
*stmt
)
2962 if (stmt_could_throw_p (ifun
, stmt
))
2964 return remove_stmt_from_eh_lp_fn (ifun
, stmt
);
2967 /* Likewise, but always use the current function. */
2970 maybe_clean_eh_stmt (gimple
*stmt
)
2972 return maybe_clean_eh_stmt_fn (cfun
, stmt
);
2975 /* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
2976 OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
2977 in the table if it should be in there. Return TRUE if a replacement was
2978 done that my require an EH edge purge. */
2981 maybe_clean_or_replace_eh_stmt (gimple
*old_stmt
, gimple
*new_stmt
)
2983 int lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2987 bool new_stmt_could_throw
= stmt_could_throw_p (cfun
, new_stmt
);
2989 if (new_stmt
== old_stmt
&& new_stmt_could_throw
)
2992 remove_stmt_from_eh_lp (old_stmt
);
2993 if (new_stmt_could_throw
)
2995 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
3005 /* Given a statement OLD_STMT in OLD_FUN and a duplicate statement NEW_STMT
3006 in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT. The MAP
3007 operand is the return value of duplicate_eh_regions. */
3010 maybe_duplicate_eh_stmt_fn (struct function
*new_fun
, gimple
*new_stmt
,
3011 struct function
*old_fun
, gimple
*old_stmt
,
3012 hash_map
<void *, void *> *map
,
3015 int old_lp_nr
, new_lp_nr
;
3017 if (!stmt_could_throw_p (new_fun
, new_stmt
))
3020 old_lp_nr
= lookup_stmt_eh_lp_fn (old_fun
, old_stmt
);
3023 if (default_lp_nr
== 0)
3025 new_lp_nr
= default_lp_nr
;
3027 else if (old_lp_nr
> 0)
3029 eh_landing_pad old_lp
, new_lp
;
3031 old_lp
= (*old_fun
->eh
->lp_array
)[old_lp_nr
];
3032 new_lp
= static_cast<eh_landing_pad
> (*map
->get (old_lp
));
3033 new_lp_nr
= new_lp
->index
;
3037 eh_region old_r
, new_r
;
3039 old_r
= (*old_fun
->eh
->region_array
)[-old_lp_nr
];
3040 new_r
= static_cast<eh_region
> (*map
->get (old_r
));
3041 new_lp_nr
= -new_r
->index
;
3044 add_stmt_to_eh_lp_fn (new_fun
, new_stmt
, new_lp_nr
);
3048 /* Similar, but both OLD_STMT and NEW_STMT are within the current function,
3049 and thus no remapping is required. */
3052 maybe_duplicate_eh_stmt (gimple
*new_stmt
, gimple
*old_stmt
)
3056 if (!stmt_could_throw_p (cfun
, new_stmt
))
3059 lp_nr
= lookup_stmt_eh_lp (old_stmt
);
3063 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
3067 /* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of
3068 GIMPLE_TRY) that are similar enough to be considered the same. Currently
3069 this only handles handlers consisting of a single call, as that's the
3070 important case for C++: a destructor call for a particular object showing
3071 up in multiple handlers. */
3074 same_handler_p (gimple_seq oneh
, gimple_seq twoh
)
3076 gimple_stmt_iterator gsi
;
3077 gimple
*ones
, *twos
;
3080 gsi
= gsi_start (oneh
);
3081 if (!gsi_one_before_end_p (gsi
))
3083 ones
= gsi_stmt (gsi
);
3085 gsi
= gsi_start (twoh
);
3086 if (!gsi_one_before_end_p (gsi
))
3088 twos
= gsi_stmt (gsi
);
3090 if (!is_gimple_call (ones
)
3091 || !is_gimple_call (twos
)
3092 || gimple_call_lhs (ones
)
3093 || gimple_call_lhs (twos
)
3094 || gimple_call_chain (ones
)
3095 || gimple_call_chain (twos
)
3096 || !gimple_call_same_target_p (ones
, twos
)
3097 || gimple_call_num_args (ones
) != gimple_call_num_args (twos
))
3100 for (ai
= 0; ai
< gimple_call_num_args (ones
); ++ai
)
3101 if (!operand_equal_p (gimple_call_arg (ones
, ai
),
3102 gimple_call_arg (twos
, ai
), 0))
3109 try { A() } finally { try { ~B() } catch { ~A() } }
3110 try { ... } finally { ~A() }
3112 try { A() } catch { ~B() }
3113 try { ~B() ... } finally { ~A() }
3115 This occurs frequently in C++, where A is a local variable and B is a
3116 temporary used in the initializer for A. */
3119 optimize_double_finally (gtry
*one
, gtry
*two
)
3122 gimple_stmt_iterator gsi
;
3125 cleanup
= gimple_try_cleanup (one
);
3126 gsi
= gsi_start (cleanup
);
3127 if (!gsi_one_before_end_p (gsi
))
3130 oneh
= gsi_stmt (gsi
);
3131 if (gimple_code (oneh
) != GIMPLE_TRY
3132 || gimple_try_kind (oneh
) != GIMPLE_TRY_CATCH
)
3135 if (same_handler_p (gimple_try_cleanup (oneh
), gimple_try_cleanup (two
)))
3137 gimple_seq seq
= gimple_try_eval (oneh
);
3139 gimple_try_set_cleanup (one
, seq
);
3140 gimple_try_set_kind (one
, GIMPLE_TRY_CATCH
);
3141 seq
= copy_gimple_seq_and_replace_locals (seq
);
3142 gimple_seq_add_seq (&seq
, gimple_try_eval (two
));
3143 gimple_try_set_eval (two
, seq
);
3147 /* Perform EH refactoring optimizations that are simpler to do when code
3148 flow has been lowered but EH structures haven't. */
3151 refactor_eh_r (gimple_seq seq
)
3153 gimple_stmt_iterator gsi
;
3158 gsi
= gsi_start (seq
);
3162 if (gsi_end_p (gsi
))
3165 two
= gsi_stmt (gsi
);
3167 if (gtry
*try_one
= dyn_cast
<gtry
*> (one
))
3168 if (gtry
*try_two
= dyn_cast
<gtry
*> (two
))
3169 if (gimple_try_kind (try_one
) == GIMPLE_TRY_FINALLY
3170 && gimple_try_kind (try_two
) == GIMPLE_TRY_FINALLY
)
3171 optimize_double_finally (try_one
, try_two
);
3173 switch (gimple_code (one
))
3176 refactor_eh_r (gimple_try_eval (one
));
3177 refactor_eh_r (gimple_try_cleanup (one
));
3180 refactor_eh_r (gimple_catch_handler (as_a
<gcatch
*> (one
)));
3182 case GIMPLE_EH_FILTER
:
3183 refactor_eh_r (gimple_eh_filter_failure (one
));
3185 case GIMPLE_EH_ELSE
:
3187 geh_else
*eh_else_stmt
= as_a
<geh_else
*> (one
);
3188 refactor_eh_r (gimple_eh_else_n_body (eh_else_stmt
));
3189 refactor_eh_r (gimple_eh_else_e_body (eh_else_stmt
));
3204 const pass_data pass_data_refactor_eh
=
3206 GIMPLE_PASS
, /* type */
3208 OPTGROUP_NONE
, /* optinfo_flags */
3209 TV_TREE_EH
, /* tv_id */
3210 PROP_gimple_lcf
, /* properties_required */
3211 0, /* properties_provided */
3212 0, /* properties_destroyed */
3213 0, /* todo_flags_start */
3214 0, /* todo_flags_finish */
3217 class pass_refactor_eh
: public gimple_opt_pass
3220 pass_refactor_eh (gcc::context
*ctxt
)
3221 : gimple_opt_pass (pass_data_refactor_eh
, ctxt
)
3224 /* opt_pass methods: */
3225 virtual bool gate (function
*) { return flag_exceptions
!= 0; }
3226 virtual unsigned int execute (function
*)
3228 refactor_eh_r (gimple_body (current_function_decl
));
3232 }; // class pass_refactor_eh
3237 make_pass_refactor_eh (gcc::context
*ctxt
)
3239 return new pass_refactor_eh (ctxt
);
3242 /* At the end of gimple optimization, we can lower RESX. */
3245 lower_resx (basic_block bb
, gresx
*stmt
,
3246 hash_map
<eh_region
, tree
> *mnt_map
)
3249 eh_region src_r
, dst_r
;
3250 gimple_stmt_iterator gsi
;
3255 lp_nr
= lookup_stmt_eh_lp (stmt
);
3257 dst_r
= get_eh_region_from_lp_number (lp_nr
);
3261 src_r
= get_eh_region_from_number (gimple_resx_region (stmt
));
3262 gsi
= gsi_last_bb (bb
);
3266 /* We can wind up with no source region when pass_cleanup_eh shows
3267 that there are no entries into an eh region and deletes it, but
3268 then the block that contains the resx isn't removed. This can
3269 happen without optimization when the switch statement created by
3270 lower_try_finally_switch isn't simplified to remove the eh case.
3272 Resolve this by expanding the resx node to an abort. */
3274 fn
= builtin_decl_implicit (BUILT_IN_TRAP
);
3275 x
= gimple_build_call (fn
, 0);
3276 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3278 while (EDGE_COUNT (bb
->succs
) > 0)
3279 remove_edge (EDGE_SUCC (bb
, 0));
3283 /* When we have a destination region, we resolve this by copying
3284 the excptr and filter values into place, and changing the edge
3285 to immediately after the landing pad. */
3293 /* We are resuming into a MUST_NOT_CALL region. Expand a call to
3294 the failure decl into a new block, if needed. */
3295 gcc_assert (dst_r
->type
== ERT_MUST_NOT_THROW
);
3297 tree
*slot
= mnt_map
->get (dst_r
);
3300 gimple_stmt_iterator gsi2
;
3302 new_bb
= create_empty_bb (bb
);
3303 new_bb
->count
= bb
->count
;
3304 add_bb_to_loop (new_bb
, bb
->loop_father
);
3305 lab
= gimple_block_label (new_bb
);
3306 gsi2
= gsi_start_bb (new_bb
);
3308 fn
= dst_r
->u
.must_not_throw
.failure_decl
;
3309 x
= gimple_build_call (fn
, 0);
3310 gimple_set_location (x
, dst_r
->u
.must_not_throw
.failure_loc
);
3311 gsi_insert_after (&gsi2
, x
, GSI_CONTINUE_LINKING
);
3313 mnt_map
->put (dst_r
, lab
);
3318 new_bb
= label_to_block (cfun
, lab
);
3321 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3322 e
= make_single_succ_edge (bb
, new_bb
, EDGE_FALLTHRU
);
3327 tree dst_nr
= build_int_cst (integer_type_node
, dst_r
->index
);
3329 fn
= builtin_decl_implicit (BUILT_IN_EH_COPY_VALUES
);
3330 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3331 x
= gimple_build_call (fn
, 2, dst_nr
, src_nr
);
3332 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3334 /* Update the flags for the outgoing edge. */
3335 e
= single_succ_edge (bb
);
3336 gcc_assert (e
->flags
& EDGE_EH
);
3337 e
->flags
= (e
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
3338 e
->probability
= profile_probability::always ();
3340 /* If there are no more EH users of the landing pad, delete it. */
3341 FOR_EACH_EDGE (e
, ei
, e
->dest
->preds
)
3342 if (e
->flags
& EDGE_EH
)
3346 eh_landing_pad lp
= get_eh_landing_pad_from_number (lp_nr
);
3347 remove_eh_landing_pad (lp
);
3357 /* When we don't have a destination region, this exception escapes
3358 up the call chain. We resolve this by generating a call to the
3359 _Unwind_Resume library function. */
3361 /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup
3362 with no arguments for C++. Check for that. */
3363 if (src_r
->use_cxa_end_cleanup
)
3365 fn
= builtin_decl_implicit (BUILT_IN_CXA_END_CLEANUP
);
3366 x
= gimple_build_call (fn
, 0);
3367 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3371 fn
= builtin_decl_implicit (BUILT_IN_EH_POINTER
);
3372 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3373 x
= gimple_build_call (fn
, 1, src_nr
);
3374 var
= create_tmp_var (ptr_type_node
);
3375 var
= make_ssa_name (var
, x
);
3376 gimple_call_set_lhs (x
, var
);
3377 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3379 /* When exception handling is delegated to a caller function, we
3380 have to guarantee that shadow memory variables living on stack
3381 will be cleaner before control is given to a parent function. */
3382 if (sanitize_flags_p (SANITIZE_ADDRESS
))
3385 = builtin_decl_implicit (BUILT_IN_ASAN_HANDLE_NO_RETURN
);
3386 gimple
*g
= gimple_build_call (decl
, 0);
3387 gimple_set_location (g
, gimple_location (stmt
));
3388 gsi_insert_before (&gsi
, g
, GSI_SAME_STMT
);
3391 fn
= builtin_decl_implicit (BUILT_IN_UNWIND_RESUME
);
3392 x
= gimple_build_call (fn
, 1, var
);
3393 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3396 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3399 gsi_remove (&gsi
, true);
3406 const pass_data pass_data_lower_resx
=
3408 GIMPLE_PASS
, /* type */
3410 OPTGROUP_NONE
, /* optinfo_flags */
3411 TV_TREE_EH
, /* tv_id */
3412 PROP_gimple_lcf
, /* properties_required */
3413 0, /* properties_provided */
3414 0, /* properties_destroyed */
3415 0, /* todo_flags_start */
3416 0, /* todo_flags_finish */
3419 class pass_lower_resx
: public gimple_opt_pass
3422 pass_lower_resx (gcc::context
*ctxt
)
3423 : gimple_opt_pass (pass_data_lower_resx
, ctxt
)
3426 /* opt_pass methods: */
3427 virtual bool gate (function
*) { return flag_exceptions
!= 0; }
3428 virtual unsigned int execute (function
*);
3430 }; // class pass_lower_resx
3433 pass_lower_resx::execute (function
*fun
)
3436 bool dominance_invalidated
= false;
3437 bool any_rewritten
= false;
3439 hash_map
<eh_region
, tree
> mnt_map
;
3441 FOR_EACH_BB_FN (bb
, fun
)
3443 gimple
*last
= last_stmt (bb
);
3444 if (last
&& is_gimple_resx (last
))
3446 dominance_invalidated
|=
3447 lower_resx (bb
, as_a
<gresx
*> (last
), &mnt_map
);
3448 any_rewritten
= true;
3452 if (dominance_invalidated
)
3454 free_dominance_info (CDI_DOMINATORS
);
3455 free_dominance_info (CDI_POST_DOMINATORS
);
3458 return any_rewritten
? TODO_update_ssa_only_virtuals
: 0;
3464 make_pass_lower_resx (gcc::context
*ctxt
)
3466 return new pass_lower_resx (ctxt
);
3469 /* Try to optimize var = {v} {CLOBBER} stmts followed just by
3473 optimize_clobbers (basic_block bb
)
3475 gimple_stmt_iterator gsi
= gsi_last_bb (bb
);
3476 bool any_clobbers
= false;
3477 bool seen_stack_restore
= false;
3481 /* Only optimize anything if the bb contains at least one clobber,
3482 ends with resx (checked by caller), optionally contains some
3483 debug stmts or labels, or at most one __builtin_stack_restore
3484 call, and has an incoming EH edge. */
3485 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3487 gimple
*stmt
= gsi_stmt (gsi
);
3488 if (is_gimple_debug (stmt
))
3490 if (gimple_clobber_p (stmt
))
3492 any_clobbers
= true;
3495 if (!seen_stack_restore
3496 && gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
3498 seen_stack_restore
= true;
3501 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3507 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3508 if (e
->flags
& EDGE_EH
)
3512 gsi
= gsi_last_bb (bb
);
3513 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3515 gimple
*stmt
= gsi_stmt (gsi
);
3516 if (!gimple_clobber_p (stmt
))
3518 unlink_stmt_vdef (stmt
);
3519 gsi_remove (&gsi
, true);
3520 release_defs (stmt
);
3524 /* Try to sink var = {v} {CLOBBER} stmts followed just by
3525 internal throw to successor BB. */
3528 sink_clobbers (basic_block bb
)
3532 gimple_stmt_iterator gsi
, dgsi
;
3534 bool any_clobbers
= false;
3537 /* Only optimize if BB has a single EH successor and
3538 all predecessor edges are EH too. */
3539 if (!single_succ_p (bb
)
3540 || (single_succ_edge (bb
)->flags
& EDGE_EH
) == 0)
3543 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3545 if ((e
->flags
& EDGE_EH
) == 0)
3549 /* And BB contains only CLOBBER stmts before the final
3551 gsi
= gsi_last_bb (bb
);
3552 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3554 gimple
*stmt
= gsi_stmt (gsi
);
3555 if (is_gimple_debug (stmt
))
3557 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3559 if (!gimple_clobber_p (stmt
))
3561 any_clobbers
= true;
3566 edge succe
= single_succ_edge (bb
);
3567 succbb
= succe
->dest
;
3569 /* See if there is a virtual PHI node to take an updated virtual
3572 tree vuse
= NULL_TREE
;
3573 for (gphi_iterator gpi
= gsi_start_phis (succbb
);
3574 !gsi_end_p (gpi
); gsi_next (&gpi
))
3576 tree res
= gimple_phi_result (gpi
.phi ());
3577 if (virtual_operand_p (res
))
3585 dgsi
= gsi_after_labels (succbb
);
3586 gsi
= gsi_last_bb (bb
);
3587 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3589 gimple
*stmt
= gsi_stmt (gsi
);
3591 if (is_gimple_debug (stmt
))
3593 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3595 lhs
= gimple_assign_lhs (stmt
);
3596 /* Unfortunately we don't have dominance info updated at this
3597 point, so checking if
3598 dominated_by_p (CDI_DOMINATORS, succbb,
3599 gimple_bb (SSA_NAME_DEF_STMT (TREE_OPERAND (lhs, 0)))
3600 would be too costly. Thus, avoid sinking any clobbers that
3601 refer to non-(D) SSA_NAMEs. */
3602 if (TREE_CODE (lhs
) == MEM_REF
3603 && TREE_CODE (TREE_OPERAND (lhs
, 0)) == SSA_NAME
3604 && !SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs
, 0)))
3606 unlink_stmt_vdef (stmt
);
3607 gsi_remove (&gsi
, true);
3608 release_defs (stmt
);
3612 /* As we do not change stmt order when sinking across a
3613 forwarder edge we can keep virtual operands in place. */
3614 gsi_remove (&gsi
, false);
3615 gsi_insert_before (&dgsi
, stmt
, GSI_NEW_STMT
);
3617 /* But adjust virtual operands if we sunk across a PHI node. */
3621 imm_use_iterator iter
;
3622 use_operand_p use_p
;
3623 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, vuse
)
3624 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
3625 SET_USE (use_p
, gimple_vdef (stmt
));
3626 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
))
3628 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vdef (stmt
)) = 1;
3629 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
) = 0;
3631 /* Adjust the incoming virtual operand. */
3632 SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (vphi
, succe
), gimple_vuse (stmt
));
3633 SET_USE (gimple_vuse_op (stmt
), vuse
);
3635 /* If there isn't a single predecessor but no virtual PHI node
3636 arrange for virtual operands to be renamed. */
3637 else if (gimple_vuse_op (stmt
) != NULL_USE_OPERAND_P
3638 && !single_pred_p (succbb
))
3640 /* In this case there will be no use of the VDEF of this stmt.
3641 ??? Unless this is a secondary opportunity and we have not
3642 removed unreachable blocks yet, so we cannot assert this.
3643 Which also means we will end up renaming too many times. */
3644 SET_USE (gimple_vuse_op (stmt
), gimple_vop (cfun
));
3645 mark_virtual_operands_for_renaming (cfun
);
3646 todo
|= TODO_update_ssa_only_virtuals
;
3653 /* At the end of inlining, we can lower EH_DISPATCH. Return true when
3654 we have found some duplicate labels and removed some edges. */
3657 lower_eh_dispatch (basic_block src
, geh_dispatch
*stmt
)
3659 gimple_stmt_iterator gsi
;
3664 bool redirected
= false;
3666 region_nr
= gimple_eh_dispatch_region (stmt
);
3667 r
= get_eh_region_from_number (region_nr
);
3669 gsi
= gsi_last_bb (src
);
3675 auto_vec
<tree
> labels
;
3676 tree default_label
= NULL
;
3680 hash_set
<tree
> seen_values
;
3682 /* Collect the labels for a switch. Zero the post_landing_pad
3683 field becase we'll no longer have anything keeping these labels
3684 in existence and the optimizer will be free to merge these
3686 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
3688 tree tp_node
, flt_node
, lab
= c
->label
;
3689 bool have_label
= false;
3692 tp_node
= c
->type_list
;
3693 flt_node
= c
->filter_list
;
3695 if (tp_node
== NULL
)
3697 default_label
= lab
;
3702 /* Filter out duplicate labels that arise when this handler
3703 is shadowed by an earlier one. When no labels are
3704 attached to the handler anymore, we remove
3705 the corresponding edge and then we delete unreachable
3706 blocks at the end of this pass. */
3707 if (! seen_values
.contains (TREE_VALUE (flt_node
)))
3709 tree t
= build_case_label (TREE_VALUE (flt_node
),
3711 labels
.safe_push (t
);
3712 seen_values
.add (TREE_VALUE (flt_node
));
3716 tp_node
= TREE_CHAIN (tp_node
);
3717 flt_node
= TREE_CHAIN (flt_node
);
3722 remove_edge (find_edge (src
, label_to_block (cfun
, lab
)));
3727 /* Clean up the edge flags. */
3728 FOR_EACH_EDGE (e
, ei
, src
->succs
)
3730 if (e
->flags
& EDGE_FALLTHRU
)
3732 /* If there was no catch-all, use the fallthru edge. */
3733 if (default_label
== NULL
)
3734 default_label
= gimple_block_label (e
->dest
);
3735 e
->flags
&= ~EDGE_FALLTHRU
;
3738 gcc_assert (default_label
!= NULL
);
3740 /* Don't generate a switch if there's only a default case.
3741 This is common in the form of try { A; } catch (...) { B; }. */
3742 if (!labels
.exists ())
3744 e
= single_succ_edge (src
);
3745 e
->flags
|= EDGE_FALLTHRU
;
3749 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3750 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3752 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)));
3753 filter
= make_ssa_name (filter
, x
);
3754 gimple_call_set_lhs (x
, filter
);
3755 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3757 /* Turn the default label into a default case. */
3758 default_label
= build_case_label (NULL
, NULL
, default_label
);
3759 sort_case_labels (labels
);
3761 x
= gimple_build_switch (filter
, default_label
, labels
);
3762 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3767 case ERT_ALLOWED_EXCEPTIONS
:
3769 edge b_e
= BRANCH_EDGE (src
);
3770 edge f_e
= FALLTHRU_EDGE (src
);
3772 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3773 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3775 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)));
3776 filter
= make_ssa_name (filter
, x
);
3777 gimple_call_set_lhs (x
, filter
);
3778 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3780 r
->u
.allowed
.label
= NULL
;
3781 x
= gimple_build_cond (EQ_EXPR
, filter
,
3782 build_int_cst (TREE_TYPE (filter
),
3783 r
->u
.allowed
.filter
),
3784 NULL_TREE
, NULL_TREE
);
3785 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3787 b_e
->flags
= b_e
->flags
| EDGE_TRUE_VALUE
;
3788 f_e
->flags
= (f_e
->flags
& ~EDGE_FALLTHRU
) | EDGE_FALSE_VALUE
;
3796 /* Replace the EH_DISPATCH with the SWITCH or COND generated above. */
3797 gsi_remove (&gsi
, true);
3803 const pass_data pass_data_lower_eh_dispatch
=
3805 GIMPLE_PASS
, /* type */
3806 "ehdisp", /* name */
3807 OPTGROUP_NONE
, /* optinfo_flags */
3808 TV_TREE_EH
, /* tv_id */
3809 PROP_gimple_lcf
, /* properties_required */
3810 0, /* properties_provided */
3811 0, /* properties_destroyed */
3812 0, /* todo_flags_start */
3813 0, /* todo_flags_finish */
3816 class pass_lower_eh_dispatch
: public gimple_opt_pass
3819 pass_lower_eh_dispatch (gcc::context
*ctxt
)
3820 : gimple_opt_pass (pass_data_lower_eh_dispatch
, ctxt
)
3823 /* opt_pass methods: */
3824 virtual bool gate (function
*fun
) { return fun
->eh
->region_tree
!= NULL
; }
3825 virtual unsigned int execute (function
*);
3827 }; // class pass_lower_eh_dispatch
3830 pass_lower_eh_dispatch::execute (function
*fun
)
3834 bool redirected
= false;
3836 assign_filter_values ();
3838 FOR_EACH_BB_FN (bb
, fun
)
3840 gimple
*last
= last_stmt (bb
);
3843 if (gimple_code (last
) == GIMPLE_EH_DISPATCH
)
3845 redirected
|= lower_eh_dispatch (bb
,
3846 as_a
<geh_dispatch
*> (last
));
3847 flags
|= TODO_update_ssa_only_virtuals
;
3849 else if (gimple_code (last
) == GIMPLE_RESX
)
3851 if (stmt_can_throw_external (cfun
, last
))
3852 optimize_clobbers (bb
);
3854 flags
|= sink_clobbers (bb
);
3860 free_dominance_info (CDI_DOMINATORS
);
3861 delete_unreachable_blocks ();
3869 make_pass_lower_eh_dispatch (gcc::context
*ctxt
)
3871 return new pass_lower_eh_dispatch (ctxt
);
3874 /* Walk statements, see what regions and, optionally, landing pads
3875 are really referenced.
3877 Returns in R_REACHABLEP an sbitmap with bits set for reachable regions,
3878 and in LP_REACHABLE an sbitmap with bits set for reachable landing pads.
3880 Passing NULL for LP_REACHABLE is valid, in this case only reachable
3883 The caller is responsible for freeing the returned sbitmaps. */
3886 mark_reachable_handlers (sbitmap
*r_reachablep
, sbitmap
*lp_reachablep
)
3888 sbitmap r_reachable
, lp_reachable
;
3890 bool mark_landing_pads
= (lp_reachablep
!= NULL
);
3891 gcc_checking_assert (r_reachablep
!= NULL
);
3893 r_reachable
= sbitmap_alloc (cfun
->eh
->region_array
->length ());
3894 bitmap_clear (r_reachable
);
3895 *r_reachablep
= r_reachable
;
3897 if (mark_landing_pads
)
3899 lp_reachable
= sbitmap_alloc (cfun
->eh
->lp_array
->length ());
3900 bitmap_clear (lp_reachable
);
3901 *lp_reachablep
= lp_reachable
;
3904 lp_reachable
= NULL
;
3906 FOR_EACH_BB_FN (bb
, cfun
)
3908 gimple_stmt_iterator gsi
;
3910 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3912 gimple
*stmt
= gsi_stmt (gsi
);
3914 if (mark_landing_pads
)
3916 int lp_nr
= lookup_stmt_eh_lp (stmt
);
3918 /* Negative LP numbers are MUST_NOT_THROW regions which
3919 are not considered BB enders. */
3921 bitmap_set_bit (r_reachable
, -lp_nr
);
3923 /* Positive LP numbers are real landing pads, and BB enders. */
3926 gcc_assert (gsi_one_before_end_p (gsi
));
3927 eh_region region
= get_eh_region_from_lp_number (lp_nr
);
3928 bitmap_set_bit (r_reachable
, region
->index
);
3929 bitmap_set_bit (lp_reachable
, lp_nr
);
3933 /* Avoid removing regions referenced from RESX/EH_DISPATCH. */
3934 switch (gimple_code (stmt
))
3937 bitmap_set_bit (r_reachable
,
3938 gimple_resx_region (as_a
<gresx
*> (stmt
)));
3940 case GIMPLE_EH_DISPATCH
:
3941 bitmap_set_bit (r_reachable
,
3942 gimple_eh_dispatch_region (
3943 as_a
<geh_dispatch
*> (stmt
)));
3946 if (gimple_call_builtin_p (stmt
, BUILT_IN_EH_COPY_VALUES
))
3947 for (int i
= 0; i
< 2; ++i
)
3949 tree rt
= gimple_call_arg (stmt
, i
);
3950 HOST_WIDE_INT ri
= tree_to_shwi (rt
);
3952 gcc_assert (ri
== (int)ri
);
3953 bitmap_set_bit (r_reachable
, ri
);
3963 /* Remove unreachable handlers and unreachable landing pads. */
3966 remove_unreachable_handlers (void)
3968 sbitmap r_reachable
, lp_reachable
;
3973 mark_reachable_handlers (&r_reachable
, &lp_reachable
);
3977 fprintf (dump_file
, "Before removal of unreachable regions:\n");
3978 dump_eh_tree (dump_file
, cfun
);
3979 fprintf (dump_file
, "Reachable regions: ");
3980 dump_bitmap_file (dump_file
, r_reachable
);
3981 fprintf (dump_file
, "Reachable landing pads: ");
3982 dump_bitmap_file (dump_file
, lp_reachable
);
3987 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3988 if (region
&& !bitmap_bit_p (r_reachable
, region
->index
))
3990 "Removing unreachable region %d\n",
3994 remove_unreachable_eh_regions (r_reachable
);
3996 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3997 if (lp
&& !bitmap_bit_p (lp_reachable
, lp
->index
))
4001 "Removing unreachable landing pad %d\n",
4003 remove_eh_landing_pad (lp
);
4008 fprintf (dump_file
, "\n\nAfter removal of unreachable regions:\n");
4009 dump_eh_tree (dump_file
, cfun
);
4010 fprintf (dump_file
, "\n\n");
4013 sbitmap_free (r_reachable
);
4014 sbitmap_free (lp_reachable
);
4017 verify_eh_tree (cfun
);
4020 /* Remove unreachable handlers if any landing pads have been removed after
4021 last ehcleanup pass (due to gimple_purge_dead_eh_edges). */
4024 maybe_remove_unreachable_handlers (void)
4029 if (cfun
->eh
== NULL
)
4032 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
4033 if (lp
&& lp
->post_landing_pad
)
4035 if (label_to_block (cfun
, lp
->post_landing_pad
) == NULL
)
4037 remove_unreachable_handlers ();
4043 /* Remove regions that do not have landing pads. This assumes
4044 that remove_unreachable_handlers has already been run, and
4045 that we've just manipulated the landing pads since then.
4047 Preserve regions with landing pads and regions that prevent
4048 exceptions from propagating further, even if these regions
4049 are not reachable. */
4052 remove_unreachable_handlers_no_lp (void)
4055 sbitmap r_reachable
;
4058 mark_reachable_handlers (&r_reachable
, /*lp_reachablep=*/NULL
);
4060 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
4065 if (region
->landing_pads
!= NULL
4066 || region
->type
== ERT_MUST_NOT_THROW
)
4067 bitmap_set_bit (r_reachable
, region
->index
);
4070 && !bitmap_bit_p (r_reachable
, region
->index
))
4072 "Removing unreachable region %d\n",
4076 remove_unreachable_eh_regions (r_reachable
);
4078 sbitmap_free (r_reachable
);
4081 /* Undo critical edge splitting on an EH landing pad. Earlier, we
4082 optimisticaly split all sorts of edges, including EH edges. The
4083 optimization passes in between may not have needed them; if not,
4084 we should undo the split.
4086 Recognize this case by having one EH edge incoming to the BB and
4087 one normal edge outgoing; BB should be empty apart from the
4088 post_landing_pad label.
4090 Note that this is slightly different from the empty handler case
4091 handled by cleanup_empty_eh, in that the actual handler may yet
4092 have actual code but the landing pad has been separated from the
4093 handler. As such, cleanup_empty_eh relies on this transformation
4094 having been done first. */
4097 unsplit_eh (eh_landing_pad lp
)
4099 basic_block bb
= label_to_block (cfun
, lp
->post_landing_pad
);
4100 gimple_stmt_iterator gsi
;
4103 /* Quickly check the edge counts on BB for singularity. */
4104 if (!single_pred_p (bb
) || !single_succ_p (bb
))
4106 e_in
= single_pred_edge (bb
);
4107 e_out
= single_succ_edge (bb
);
4109 /* Input edge must be EH and output edge must be normal. */
4110 if ((e_in
->flags
& EDGE_EH
) == 0 || (e_out
->flags
& EDGE_EH
) != 0)
4113 /* The block must be empty except for the labels and debug insns. */
4114 gsi
= gsi_after_labels (bb
);
4115 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4116 gsi_next_nondebug (&gsi
);
4117 if (!gsi_end_p (gsi
))
4120 /* The destination block must not already have a landing pad
4121 for a different region. */
4122 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4124 glabel
*label_stmt
= dyn_cast
<glabel
*> (gsi_stmt (gsi
));
4130 lab
= gimple_label_label (label_stmt
);
4131 lp_nr
= EH_LANDING_PAD_NR (lab
);
4132 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4136 /* The new destination block must not already be a destination of
4137 the source block, lest we merge fallthru and eh edges and get
4138 all sorts of confused. */
4139 if (find_edge (e_in
->src
, e_out
->dest
))
4142 /* ??? We can get degenerate phis due to cfg cleanups. I would have
4143 thought this should have been cleaned up by a phicprop pass, but
4144 that doesn't appear to handle virtuals. Propagate by hand. */
4145 if (!gimple_seq_empty_p (phi_nodes (bb
)))
4147 for (gphi_iterator gpi
= gsi_start_phis (bb
); !gsi_end_p (gpi
); )
4150 gphi
*phi
= gpi
.phi ();
4151 tree lhs
= gimple_phi_result (phi
);
4152 tree rhs
= gimple_phi_arg_def (phi
, 0);
4153 use_operand_p use_p
;
4154 imm_use_iterator iter
;
4156 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
4158 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
4159 SET_USE (use_p
, rhs
);
4162 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
4163 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs
) = 1;
4165 remove_phi_node (&gpi
, true);
4169 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4170 fprintf (dump_file
, "Unsplit EH landing pad %d to block %i.\n",
4171 lp
->index
, e_out
->dest
->index
);
4173 /* Redirect the edge. Since redirect_eh_edge_1 expects to be moving
4174 a successor edge, humor it. But do the real CFG change with the
4175 predecessor of E_OUT in order to preserve the ordering of arguments
4176 to the PHI nodes in E_OUT->DEST. */
4177 redirect_eh_edge_1 (e_in
, e_out
->dest
, false);
4178 redirect_edge_pred (e_out
, e_in
->src
);
4179 e_out
->flags
= e_in
->flags
;
4180 e_out
->probability
= e_in
->probability
;
4186 /* Examine each landing pad block and see if it matches unsplit_eh. */
4189 unsplit_all_eh (void)
4191 bool changed
= false;
4195 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4197 changed
|= unsplit_eh (lp
);
4202 /* A subroutine of cleanup_empty_eh. Redirect all EH edges incoming
4203 to OLD_BB to NEW_BB; return true on success, false on failure.
4205 OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any
4206 PHI variables from OLD_BB we can pick them up from OLD_BB_OUT.
4207 Virtual PHIs may be deleted and marked for renaming. */
4210 cleanup_empty_eh_merge_phis (basic_block new_bb
, basic_block old_bb
,
4211 edge old_bb_out
, bool change_region
)
4213 gphi_iterator ngsi
, ogsi
;
4216 bitmap ophi_handled
;
4218 /* The destination block must not be a regular successor for any
4219 of the preds of the landing pad. Thus, avoid turning
4229 which CFG verification would choke on. See PR45172 and PR51089. */
4230 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4231 if (find_edge (e
->src
, new_bb
))
4234 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4235 redirect_edge_var_map_clear (e
);
4237 ophi_handled
= BITMAP_ALLOC (NULL
);
4239 /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
4240 for the edges we're going to move. */
4241 for (ngsi
= gsi_start_phis (new_bb
); !gsi_end_p (ngsi
); gsi_next (&ngsi
))
4243 gphi
*ophi
, *nphi
= ngsi
.phi ();
4246 nresult
= gimple_phi_result (nphi
);
4247 nop
= gimple_phi_arg_def (nphi
, old_bb_out
->dest_idx
);
4249 /* Find the corresponding PHI in OLD_BB so we can forward-propagate
4250 the source ssa_name. */
4252 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4255 if (gimple_phi_result (ophi
) == nop
)
4260 /* If we did find the corresponding PHI, copy those inputs. */
4263 /* If NOP is used somewhere else beyond phis in new_bb, give up. */
4264 if (!has_single_use (nop
))
4266 imm_use_iterator imm_iter
;
4267 use_operand_p use_p
;
4269 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, nop
)
4271 if (!gimple_debug_bind_p (USE_STMT (use_p
))
4272 && (gimple_code (USE_STMT (use_p
)) != GIMPLE_PHI
4273 || gimple_bb (USE_STMT (use_p
)) != new_bb
))
4277 bitmap_set_bit (ophi_handled
, SSA_NAME_VERSION (nop
));
4278 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4283 if ((e
->flags
& EDGE_EH
) == 0)
4285 oop
= gimple_phi_arg_def (ophi
, e
->dest_idx
);
4286 oloc
= gimple_phi_arg_location (ophi
, e
->dest_idx
);
4287 redirect_edge_var_map_add (e
, nresult
, oop
, oloc
);
4290 /* If we didn't find the PHI, if it's a real variable or a VOP, we know
4291 from the fact that OLD_BB is tree_empty_eh_handler_p that the
4292 variable is unchanged from input to the block and we can simply
4293 re-use the input to NEW_BB from the OLD_BB_OUT edge. */
4297 = gimple_phi_arg_location (nphi
, old_bb_out
->dest_idx
);
4298 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4299 redirect_edge_var_map_add (e
, nresult
, nop
, nloc
);
4303 /* Second, verify that all PHIs from OLD_BB have been handled. If not,
4304 we don't know what values from the other edges into NEW_BB to use. */
4305 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4307 gphi
*ophi
= ogsi
.phi ();
4308 tree oresult
= gimple_phi_result (ophi
);
4309 if (!bitmap_bit_p (ophi_handled
, SSA_NAME_VERSION (oresult
)))
4313 /* Finally, move the edges and update the PHIs. */
4314 for (ei
= ei_start (old_bb
->preds
); (e
= ei_safe_edge (ei
)); )
4315 if (e
->flags
& EDGE_EH
)
4317 /* ??? CFG manipluation routines do not try to update loop
4318 form on edge redirection. Do so manually here for now. */
4319 /* If we redirect a loop entry or latch edge that will either create
4320 a multiple entry loop or rotate the loop. If the loops merge
4321 we may have created a loop with multiple latches.
4322 All of this isn't easily fixed thus cancel the affected loop
4323 and mark the other loop as possibly having multiple latches. */
4324 if (e
->dest
== e
->dest
->loop_father
->header
)
4326 mark_loop_for_removal (e
->dest
->loop_father
);
4327 new_bb
->loop_father
->latch
= NULL
;
4328 loops_state_set (LOOPS_MAY_HAVE_MULTIPLE_LATCHES
);
4330 redirect_eh_edge_1 (e
, new_bb
, change_region
);
4331 redirect_edge_succ (e
, new_bb
);
4332 flush_pending_stmts (e
);
4337 BITMAP_FREE (ophi_handled
);
4341 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4342 redirect_edge_var_map_clear (e
);
4343 BITMAP_FREE (ophi_handled
);
4347 /* A subroutine of cleanup_empty_eh. Move a landing pad LP from its
4348 old region to NEW_REGION at BB. */
4351 cleanup_empty_eh_move_lp (basic_block bb
, edge e_out
,
4352 eh_landing_pad lp
, eh_region new_region
)
4354 gimple_stmt_iterator gsi
;
4357 for (pp
= &lp
->region
->landing_pads
; *pp
!= lp
; pp
= &(*pp
)->next_lp
)
4361 lp
->region
= new_region
;
4362 lp
->next_lp
= new_region
->landing_pads
;
4363 new_region
->landing_pads
= lp
;
4365 /* Delete the RESX that was matched within the empty handler block. */
4366 gsi
= gsi_last_bb (bb
);
4367 unlink_stmt_vdef (gsi_stmt (gsi
));
4368 gsi_remove (&gsi
, true);
4370 /* Clean up E_OUT for the fallthru. */
4371 e_out
->flags
= (e_out
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
4372 e_out
->probability
= profile_probability::always ();
4375 /* A subroutine of cleanup_empty_eh. Handle more complex cases of
4376 unsplitting than unsplit_eh was prepared to handle, e.g. when
4377 multiple incoming edges and phis are involved. */
4380 cleanup_empty_eh_unsplit (basic_block bb
, edge e_out
, eh_landing_pad lp
)
4382 gimple_stmt_iterator gsi
;
4385 /* We really ought not have totally lost everything following
4386 a landing pad label. Given that BB is empty, there had better
4388 gcc_assert (e_out
!= NULL
);
4390 /* The destination block must not already have a landing pad
4391 for a different region. */
4393 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4395 glabel
*stmt
= dyn_cast
<glabel
*> (gsi_stmt (gsi
));
4400 lab
= gimple_label_label (stmt
);
4401 lp_nr
= EH_LANDING_PAD_NR (lab
);
4402 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4406 /* Attempt to move the PHIs into the successor block. */
4407 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, false))
4409 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4411 "Unsplit EH landing pad %d to block %i "
4412 "(via cleanup_empty_eh).\n",
4413 lp
->index
, e_out
->dest
->index
);
4420 /* Return true if edge E_FIRST is part of an empty infinite loop
4421 or leads to such a loop through a series of single successor
4425 infinite_empty_loop_p (edge e_first
)
4427 bool inf_loop
= false;
4430 if (e_first
->dest
== e_first
->src
)
4433 e_first
->src
->aux
= (void *) 1;
4434 for (e
= e_first
; single_succ_p (e
->dest
); e
= single_succ_edge (e
->dest
))
4436 gimple_stmt_iterator gsi
;
4442 e
->dest
->aux
= (void *) 1;
4443 gsi
= gsi_after_labels (e
->dest
);
4444 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4445 gsi_next_nondebug (&gsi
);
4446 if (!gsi_end_p (gsi
))
4449 e_first
->src
->aux
= NULL
;
4450 for (e
= e_first
; e
->dest
->aux
; e
= single_succ_edge (e
->dest
))
4451 e
->dest
->aux
= NULL
;
4456 /* Examine the block associated with LP to determine if it's an empty
4457 handler for its EH region. If so, attempt to redirect EH edges to
4458 an outer region. Return true the CFG was updated in any way. This
4459 is similar to jump forwarding, just across EH edges. */
4462 cleanup_empty_eh (eh_landing_pad lp
)
4464 basic_block bb
= label_to_block (cfun
, lp
->post_landing_pad
);
4465 gimple_stmt_iterator gsi
;
4467 eh_region new_region
;
4470 bool has_non_eh_pred
;
4474 /* There can be zero or one edges out of BB. This is the quickest test. */
4475 switch (EDGE_COUNT (bb
->succs
))
4481 e_out
= single_succ_edge (bb
);
4487 gsi
= gsi_last_nondebug_bb (bb
);
4488 resx
= gsi_stmt (gsi
);
4489 if (resx
&& is_gimple_resx (resx
))
4491 if (stmt_can_throw_external (cfun
, resx
))
4492 optimize_clobbers (bb
);
4493 else if (sink_clobbers (bb
))
4497 gsi
= gsi_after_labels (bb
);
4499 /* Make sure to skip debug statements. */
4500 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4501 gsi_next_nondebug (&gsi
);
4503 /* If the block is totally empty, look for more unsplitting cases. */
4504 if (gsi_end_p (gsi
))
4506 /* For the degenerate case of an infinite loop bail out.
4507 If bb has no successors and is totally empty, which can happen e.g.
4508 because of incorrect noreturn attribute, bail out too. */
4510 || infinite_empty_loop_p (e_out
))
4513 return ret
| cleanup_empty_eh_unsplit (bb
, e_out
, lp
);
4516 /* The block should consist only of a single RESX statement, modulo a
4517 preceding call to __builtin_stack_restore if there is no outgoing
4518 edge, since the call can be eliminated in this case. */
4519 resx
= gsi_stmt (gsi
);
4520 if (!e_out
&& gimple_call_builtin_p (resx
, BUILT_IN_STACK_RESTORE
))
4522 gsi_next_nondebug (&gsi
);
4523 resx
= gsi_stmt (gsi
);
4525 if (!is_gimple_resx (resx
))
4527 gcc_assert (gsi_one_nondebug_before_end_p (gsi
));
4529 /* Determine if there are non-EH edges, or resx edges into the handler. */
4530 has_non_eh_pred
= false;
4531 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4532 if (!(e
->flags
& EDGE_EH
))
4533 has_non_eh_pred
= true;
4535 /* Find the handler that's outer of the empty handler by looking at
4536 where the RESX instruction was vectored. */
4537 new_lp_nr
= lookup_stmt_eh_lp (resx
);
4538 new_region
= get_eh_region_from_lp_number (new_lp_nr
);
4540 /* If there's no destination region within the current function,
4541 redirection is trivial via removing the throwing statements from
4542 the EH region, removing the EH edges, and allowing the block
4543 to go unreachable. */
4544 if (new_region
== NULL
)
4546 gcc_assert (e_out
== NULL
);
4547 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4548 if (e
->flags
& EDGE_EH
)
4550 gimple
*stmt
= last_stmt (e
->src
);
4551 remove_stmt_from_eh_lp (stmt
);
4559 /* If the destination region is a MUST_NOT_THROW, allow the runtime
4560 to handle the abort and allow the blocks to go unreachable. */
4561 if (new_region
->type
== ERT_MUST_NOT_THROW
)
4563 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4564 if (e
->flags
& EDGE_EH
)
4566 gimple
*stmt
= last_stmt (e
->src
);
4567 remove_stmt_from_eh_lp (stmt
);
4568 add_stmt_to_eh_lp (stmt
, new_lp_nr
);
4576 /* Try to redirect the EH edges and merge the PHIs into the destination
4577 landing pad block. If the merge succeeds, we'll already have redirected
4578 all the EH edges. The handler itself will go unreachable if there were
4580 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, true))
4583 /* Finally, if all input edges are EH edges, then we can (potentially)
4584 reduce the number of transfers from the runtime by moving the landing
4585 pad from the original region to the new region. This is a win when
4586 we remove the last CLEANUP region along a particular exception
4587 propagation path. Since nothing changes except for the region with
4588 which the landing pad is associated, the PHI nodes do not need to be
4590 if (!has_non_eh_pred
)
4592 cleanup_empty_eh_move_lp (bb
, e_out
, lp
, new_region
);
4593 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4594 fprintf (dump_file
, "Empty EH handler %i moved to EH region %i.\n",
4595 lp
->index
, new_region
->index
);
4597 /* ??? The CFG didn't change, but we may have rendered the
4598 old EH region unreachable. Trigger a cleanup there. */
4605 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4606 fprintf (dump_file
, "Empty EH handler %i removed.\n", lp
->index
);
4607 remove_eh_landing_pad (lp
);
4611 /* Do a post-order traversal of the EH region tree. Examine each
4612 post_landing_pad block and see if we can eliminate it as empty. */
4615 cleanup_all_empty_eh (void)
4617 bool changed
= false;
4621 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4623 changed
|= cleanup_empty_eh (lp
);
4628 /* Perform cleanups and lowering of exception handling
4629 1) cleanups regions with handlers doing nothing are optimized out
4630 2) MUST_NOT_THROW regions that became dead because of 1) are optimized out
4631 3) Info about regions that are containing instructions, and regions
4632 reachable via local EH edges is collected
4633 4) Eh tree is pruned for regions no longer necessary.
4635 TODO: Push MUST_NOT_THROW regions to the root of the EH tree.
4636 Unify those that have the same failure decl and locus.
4640 execute_cleanup_eh_1 (void)
4642 /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
4643 looking up unreachable landing pads. */
4644 remove_unreachable_handlers ();
4646 /* Watch out for the region tree vanishing due to all unreachable. */
4647 if (cfun
->eh
->region_tree
)
4649 bool changed
= false;
4652 changed
|= unsplit_all_eh ();
4653 changed
|= cleanup_all_empty_eh ();
4657 free_dominance_info (CDI_DOMINATORS
);
4658 free_dominance_info (CDI_POST_DOMINATORS
);
4660 /* We delayed all basic block deletion, as we may have performed
4661 cleanups on EH edges while non-EH edges were still present. */
4662 delete_unreachable_blocks ();
4664 /* We manipulated the landing pads. Remove any region that no
4665 longer has a landing pad. */
4666 remove_unreachable_handlers_no_lp ();
4668 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
4677 const pass_data pass_data_cleanup_eh
=
4679 GIMPLE_PASS
, /* type */
4680 "ehcleanup", /* name */
4681 OPTGROUP_NONE
, /* optinfo_flags */
4682 TV_TREE_EH
, /* tv_id */
4683 PROP_gimple_lcf
, /* properties_required */
4684 0, /* properties_provided */
4685 0, /* properties_destroyed */
4686 0, /* todo_flags_start */
4687 0, /* todo_flags_finish */
4690 class pass_cleanup_eh
: public gimple_opt_pass
4693 pass_cleanup_eh (gcc::context
*ctxt
)
4694 : gimple_opt_pass (pass_data_cleanup_eh
, ctxt
)
4697 /* opt_pass methods: */
4698 opt_pass
* clone () { return new pass_cleanup_eh (m_ctxt
); }
4699 virtual bool gate (function
*fun
)
4701 return fun
->eh
!= NULL
&& fun
->eh
->region_tree
!= NULL
;
4704 virtual unsigned int execute (function
*);
4706 }; // class pass_cleanup_eh
4709 pass_cleanup_eh::execute (function
*fun
)
4711 int ret
= execute_cleanup_eh_1 ();
4713 /* If the function no longer needs an EH personality routine
4714 clear it. This exposes cross-language inlining opportunities
4715 and avoids references to a never defined personality routine. */
4716 if (DECL_FUNCTION_PERSONALITY (current_function_decl
)
4717 && function_needs_eh_personality (fun
) != eh_personality_lang
)
4718 DECL_FUNCTION_PERSONALITY (current_function_decl
) = NULL_TREE
;
4726 make_pass_cleanup_eh (gcc::context
*ctxt
)
4728 return new pass_cleanup_eh (ctxt
);
4731 /* Verify that BB containing STMT as the last statement, has precisely the
4732 edge that make_eh_edges would create. */
4735 verify_eh_edges (gimple
*stmt
)
4737 basic_block bb
= gimple_bb (stmt
);
4738 eh_landing_pad lp
= NULL
;
4743 lp_nr
= lookup_stmt_eh_lp (stmt
);
4745 lp
= get_eh_landing_pad_from_number (lp_nr
);
4748 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4750 if (e
->flags
& EDGE_EH
)
4754 error ("BB %i has multiple EH edges", bb
->index
);
4766 error ("BB %i can not throw but has an EH edge", bb
->index
);
4772 if (!stmt_could_throw_p (cfun
, stmt
))
4774 error ("BB %i last statement has incorrectly set lp", bb
->index
);
4778 if (eh_edge
== NULL
)
4780 error ("BB %i is missing an EH edge", bb
->index
);
4784 if (eh_edge
->dest
!= label_to_block (cfun
, lp
->post_landing_pad
))
4786 error ("Incorrect EH edge %i->%i", bb
->index
, eh_edge
->dest
->index
);
4793 /* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */
4796 verify_eh_dispatch_edge (geh_dispatch
*stmt
)
4800 basic_block src
, dst
;
4801 bool want_fallthru
= true;
4805 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
4806 src
= gimple_bb (stmt
);
4808 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4809 gcc_assert (e
->aux
== NULL
);
4814 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
4816 dst
= label_to_block (cfun
, c
->label
);
4817 e
= find_edge (src
, dst
);
4820 error ("BB %i is missing an edge", src
->index
);
4825 /* A catch-all handler doesn't have a fallthru. */
4826 if (c
->type_list
== NULL
)
4828 want_fallthru
= false;
4834 case ERT_ALLOWED_EXCEPTIONS
:
4835 dst
= label_to_block (cfun
, r
->u
.allowed
.label
);
4836 e
= find_edge (src
, dst
);
4839 error ("BB %i is missing an edge", src
->index
);
4850 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4852 if (e
->flags
& EDGE_FALLTHRU
)
4854 if (fall_edge
!= NULL
)
4856 error ("BB %i too many fallthru edges", src
->index
);
4865 error ("BB %i has incorrect edge", src
->index
);
4869 if ((fall_edge
!= NULL
) ^ want_fallthru
)
4871 error ("BB %i has incorrect fallthru edge", src
->index
);