1 /* Exception handling semantics and decomposition for trees.
2 Copyright (C) 2003-2014 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
22 #include "coretypes.h"
23 #include "hash-table.h"
31 #include "pointer-set.h"
32 #include "basic-block.h"
33 #include "tree-ssa-alias.h"
34 #include "internal-fn.h"
36 #include "gimple-expr.h"
39 #include "gimple-iterator.h"
40 #include "gimple-ssa.h"
43 #include "tree-phinodes.h"
44 #include "ssa-iterators.h"
45 #include "stringpool.h"
46 #include "tree-ssanames.h"
47 #include "tree-into-ssa.h"
49 #include "tree-inline.h"
50 #include "tree-pass.h"
51 #include "langhooks.h"
52 #include "diagnostic-core.h"
55 #include "gimple-low.h"
57 /* In some instances a tree and a gimple need to be stored in a same table,
58 i.e. in hash tables. This is a structure to do this. */
59 typedef union {tree
*tp
; tree t
; gimple g
;} treemple
;
61 /* Misc functions used in this file. */
63 /* Remember and lookup EH landing pad data for arbitrary statements.
64 Really this means any statement that could_throw_p. We could
65 stuff this information into the stmt_ann data structure, but:
67 (1) We absolutely rely on this information being kept until
68 we get to rtl. Once we're done with lowering here, if we lose
69 the information there's no way to recover it!
71 (2) There are many more statements that *cannot* throw as
72 compared to those that can. We should be saving some amount
73 of space by only allocating memory for those that can throw. */
75 /* Add statement T in function IFUN to landing pad NUM. */
78 add_stmt_to_eh_lp_fn (struct function
*ifun
, gimple t
, int num
)
80 struct throw_stmt_node
*n
;
83 gcc_assert (num
!= 0);
85 n
= ggc_alloc
<throw_stmt_node
> ();
89 if (!get_eh_throw_stmt_table (ifun
))
90 set_eh_throw_stmt_table (ifun
, htab_create_ggc (31, struct_ptr_hash
,
94 slot
= htab_find_slot (get_eh_throw_stmt_table (ifun
), n
, INSERT
);
99 /* Add statement T in the current function (cfun) to EH landing pad NUM. */
102 add_stmt_to_eh_lp (gimple t
, int num
)
104 add_stmt_to_eh_lp_fn (cfun
, t
, num
);
107 /* Add statement T to the single EH landing pad in REGION. */
110 record_stmt_eh_region (eh_region region
, gimple t
)
114 if (region
->type
== ERT_MUST_NOT_THROW
)
115 add_stmt_to_eh_lp_fn (cfun
, t
, -region
->index
);
118 eh_landing_pad lp
= region
->landing_pads
;
120 lp
= gen_eh_landing_pad (region
);
122 gcc_assert (lp
->next_lp
== NULL
);
123 add_stmt_to_eh_lp_fn (cfun
, t
, lp
->index
);
128 /* Remove statement T in function IFUN from its EH landing pad. */
131 remove_stmt_from_eh_lp_fn (struct function
*ifun
, gimple t
)
133 struct throw_stmt_node dummy
;
136 if (!get_eh_throw_stmt_table (ifun
))
140 slot
= htab_find_slot (get_eh_throw_stmt_table (ifun
), &dummy
,
144 htab_clear_slot (get_eh_throw_stmt_table (ifun
), slot
);
152 /* Remove statement T in the current function (cfun) from its
156 remove_stmt_from_eh_lp (gimple t
)
158 return remove_stmt_from_eh_lp_fn (cfun
, t
);
161 /* Determine if statement T is inside an EH region in function IFUN.
162 Positive numbers indicate a landing pad index; negative numbers
163 indicate a MUST_NOT_THROW region index; zero indicates that the
164 statement is not recorded in the region table. */
167 lookup_stmt_eh_lp_fn (struct function
*ifun
, gimple t
)
169 struct throw_stmt_node
*p
, n
;
171 if (ifun
->eh
->throw_stmt_table
== NULL
)
175 p
= (struct throw_stmt_node
*) htab_find (ifun
->eh
->throw_stmt_table
, &n
);
176 return p
? p
->lp_nr
: 0;
179 /* Likewise, but always use the current function. */
182 lookup_stmt_eh_lp (gimple t
)
184 /* We can get called from initialized data when -fnon-call-exceptions
185 is on; prevent crash. */
188 return lookup_stmt_eh_lp_fn (cfun
, t
);
191 /* First pass of EH node decomposition. Build up a tree of GIMPLE_TRY_FINALLY
192 nodes and LABEL_DECL nodes. We will use this during the second phase to
193 determine if a goto leaves the body of a TRY_FINALLY_EXPR node. */
195 struct finally_tree_node
197 /* When storing a GIMPLE_TRY, we have to record a gimple. However
198 when deciding whether a GOTO to a certain LABEL_DECL (which is a
199 tree) leaves the TRY block, its necessary to record a tree in
200 this field. Thus a treemple is used. */
205 /* Hashtable helpers. */
207 struct finally_tree_hasher
: typed_free_remove
<finally_tree_node
>
209 typedef finally_tree_node value_type
;
210 typedef finally_tree_node compare_type
;
211 static inline hashval_t
hash (const value_type
*);
212 static inline bool equal (const value_type
*, const compare_type
*);
216 finally_tree_hasher::hash (const value_type
*v
)
218 return (intptr_t)v
->child
.t
>> 4;
222 finally_tree_hasher::equal (const value_type
*v
, const compare_type
*c
)
224 return v
->child
.t
== c
->child
.t
;
227 /* Note that this table is *not* marked GTY. It is short-lived. */
228 static hash_table
<finally_tree_hasher
> *finally_tree
;
231 record_in_finally_tree (treemple child
, gimple parent
)
233 struct finally_tree_node
*n
;
234 finally_tree_node
**slot
;
236 n
= XNEW (struct finally_tree_node
);
240 slot
= finally_tree
->find_slot (n
, INSERT
);
246 collect_finally_tree (gimple stmt
, gimple region
);
248 /* Go through the gimple sequence. Works with collect_finally_tree to
249 record all GIMPLE_LABEL and GIMPLE_TRY statements. */
252 collect_finally_tree_1 (gimple_seq seq
, gimple region
)
254 gimple_stmt_iterator gsi
;
256 for (gsi
= gsi_start (seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
257 collect_finally_tree (gsi_stmt (gsi
), region
);
261 collect_finally_tree (gimple stmt
, gimple region
)
265 switch (gimple_code (stmt
))
268 temp
.t
= gimple_label_label (stmt
);
269 record_in_finally_tree (temp
, region
);
273 if (gimple_try_kind (stmt
) == GIMPLE_TRY_FINALLY
)
276 record_in_finally_tree (temp
, region
);
277 collect_finally_tree_1 (gimple_try_eval (stmt
), stmt
);
278 collect_finally_tree_1 (gimple_try_cleanup (stmt
), region
);
280 else if (gimple_try_kind (stmt
) == GIMPLE_TRY_CATCH
)
282 collect_finally_tree_1 (gimple_try_eval (stmt
), region
);
283 collect_finally_tree_1 (gimple_try_cleanup (stmt
), region
);
288 collect_finally_tree_1 (gimple_catch_handler (stmt
), region
);
291 case GIMPLE_EH_FILTER
:
292 collect_finally_tree_1 (gimple_eh_filter_failure (stmt
), region
);
296 collect_finally_tree_1 (gimple_eh_else_n_body (stmt
), region
);
297 collect_finally_tree_1 (gimple_eh_else_e_body (stmt
), region
);
301 /* A type, a decl, or some kind of statement that we're not
302 interested in. Don't walk them. */
308 /* Use the finally tree to determine if a jump from START to TARGET
309 would leave the try_finally node that START lives in. */
312 outside_finally_tree (treemple start
, gimple target
)
314 struct finally_tree_node n
, *p
;
319 p
= finally_tree
->find (&n
);
324 while (start
.g
!= target
);
329 /* Second pass of EH node decomposition. Actually transform the GIMPLE_TRY
330 nodes into a set of gotos, magic labels, and eh regions.
331 The eh region creation is straight-forward, but frobbing all the gotos
332 and such into shape isn't. */
334 /* The sequence into which we record all EH stuff. This will be
335 placed at the end of the function when we're all done. */
336 static gimple_seq eh_seq
;
338 /* Record whether an EH region contains something that can throw,
339 indexed by EH region number. */
340 static bitmap eh_region_may_contain_throw_map
;
342 /* The GOTO_QUEUE is is an array of GIMPLE_GOTO and GIMPLE_RETURN
343 statements that are seen to escape this GIMPLE_TRY_FINALLY node.
344 The idea is to record a gimple statement for everything except for
345 the conditionals, which get their labels recorded. Since labels are
346 of type 'tree', we need this node to store both gimple and tree
347 objects. REPL_STMT is the sequence used to replace the goto/return
348 statement. CONT_STMT is used to store the statement that allows
349 the return/goto to jump to the original destination. */
351 struct goto_queue_node
355 gimple_seq repl_stmt
;
358 /* This is used when index >= 0 to indicate that stmt is a label (as
359 opposed to a goto stmt). */
363 /* State of the world while lowering. */
367 /* What's "current" while constructing the eh region tree. These
368 correspond to variables of the same name in cfun->eh, which we
369 don't have easy access to. */
370 eh_region cur_region
;
372 /* What's "current" for the purposes of __builtin_eh_pointer. For
373 a CATCH, this is the associated TRY. For an EH_FILTER, this is
374 the associated ALLOWED_EXCEPTIONS, etc. */
375 eh_region ehp_region
;
377 /* Processing of TRY_FINALLY requires a bit more state. This is
378 split out into a separate structure so that we don't have to
379 copy so much when processing other nodes. */
380 struct leh_tf_state
*tf
;
385 /* Pointer to the GIMPLE_TRY_FINALLY node under discussion. The
386 try_finally_expr is the original GIMPLE_TRY_FINALLY. We need to retain
387 this so that outside_finally_tree can reliably reference the tree used
388 in the collect_finally_tree data structures. */
389 gimple try_finally_expr
;
392 /* While lowering a top_p usually it is expanded into multiple statements,
393 thus we need the following field to store them. */
394 gimple_seq top_p_seq
;
396 /* The state outside this try_finally node. */
397 struct leh_state
*outer
;
399 /* The exception region created for it. */
402 /* The goto queue. */
403 struct goto_queue_node
*goto_queue
;
404 size_t goto_queue_size
;
405 size_t goto_queue_active
;
407 /* Pointer map to help in searching goto_queue when it is large. */
408 struct pointer_map_t
*goto_queue_map
;
410 /* The set of unique labels seen as entries in the goto queue. */
411 vec
<tree
> dest_array
;
413 /* A label to be added at the end of the completed transformed
414 sequence. It will be set if may_fallthru was true *at one time*,
415 though subsequent transformations may have cleared that flag. */
418 /* True if it is possible to fall out the bottom of the try block.
419 Cleared if the fallthru is converted to a goto. */
422 /* True if any entry in goto_queue is a GIMPLE_RETURN. */
425 /* True if the finally block can receive an exception edge.
426 Cleared if the exception case is handled by code duplication. */
430 static gimple_seq
lower_eh_must_not_throw (struct leh_state
*, gimple
);
432 /* Search for STMT in the goto queue. Return the replacement,
433 or null if the statement isn't in the queue. */
435 #define LARGE_GOTO_QUEUE 20
437 static void lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*seq
);
440 find_goto_replacement (struct leh_tf_state
*tf
, treemple stmt
)
445 if (tf
->goto_queue_active
< LARGE_GOTO_QUEUE
)
447 for (i
= 0; i
< tf
->goto_queue_active
; i
++)
448 if ( tf
->goto_queue
[i
].stmt
.g
== stmt
.g
)
449 return tf
->goto_queue
[i
].repl_stmt
;
453 /* If we have a large number of entries in the goto_queue, create a
454 pointer map and use that for searching. */
456 if (!tf
->goto_queue_map
)
458 tf
->goto_queue_map
= pointer_map_create ();
459 for (i
= 0; i
< tf
->goto_queue_active
; i
++)
461 slot
= pointer_map_insert (tf
->goto_queue_map
,
462 tf
->goto_queue
[i
].stmt
.g
);
463 gcc_assert (*slot
== NULL
);
464 *slot
= &tf
->goto_queue
[i
];
468 slot
= pointer_map_contains (tf
->goto_queue_map
, stmt
.g
);
470 return (((struct goto_queue_node
*) *slot
)->repl_stmt
);
475 /* A subroutine of replace_goto_queue_1. Handles the sub-clauses of a
476 lowered GIMPLE_COND. If, by chance, the replacement is a simple goto,
477 then we can just splat it in, otherwise we add the new stmts immediately
478 after the GIMPLE_COND and redirect. */
481 replace_goto_queue_cond_clause (tree
*tp
, struct leh_tf_state
*tf
,
482 gimple_stmt_iterator
*gsi
)
487 location_t loc
= gimple_location (gsi_stmt (*gsi
));
490 new_seq
= find_goto_replacement (tf
, temp
);
494 if (gimple_seq_singleton_p (new_seq
)
495 && gimple_code (gimple_seq_first_stmt (new_seq
)) == GIMPLE_GOTO
)
497 *tp
= gimple_goto_dest (gimple_seq_first_stmt (new_seq
));
501 label
= create_artificial_label (loc
);
502 /* Set the new label for the GIMPLE_COND */
505 gsi_insert_after (gsi
, gimple_build_label (label
), GSI_CONTINUE_LINKING
);
506 gsi_insert_seq_after (gsi
, gimple_seq_copy (new_seq
), GSI_CONTINUE_LINKING
);
509 /* The real work of replace_goto_queue. Returns with TSI updated to
510 point to the next statement. */
512 static void replace_goto_queue_stmt_list (gimple_seq
*, struct leh_tf_state
*);
515 replace_goto_queue_1 (gimple stmt
, struct leh_tf_state
*tf
,
516 gimple_stmt_iterator
*gsi
)
522 switch (gimple_code (stmt
))
527 seq
= find_goto_replacement (tf
, temp
);
530 gsi_insert_seq_before (gsi
, gimple_seq_copy (seq
), GSI_SAME_STMT
);
531 gsi_remove (gsi
, false);
537 replace_goto_queue_cond_clause (gimple_op_ptr (stmt
, 2), tf
, gsi
);
538 replace_goto_queue_cond_clause (gimple_op_ptr (stmt
, 3), tf
, gsi
);
542 replace_goto_queue_stmt_list (gimple_try_eval_ptr (stmt
), tf
);
543 replace_goto_queue_stmt_list (gimple_try_cleanup_ptr (stmt
), tf
);
546 replace_goto_queue_stmt_list (gimple_catch_handler_ptr (stmt
), tf
);
548 case GIMPLE_EH_FILTER
:
549 replace_goto_queue_stmt_list (gimple_eh_filter_failure_ptr (stmt
), tf
);
552 replace_goto_queue_stmt_list (gimple_eh_else_n_body_ptr (stmt
), tf
);
553 replace_goto_queue_stmt_list (gimple_eh_else_e_body_ptr (stmt
), tf
);
557 /* These won't have gotos in them. */
564 /* A subroutine of replace_goto_queue. Handles GIMPLE_SEQ. */
567 replace_goto_queue_stmt_list (gimple_seq
*seq
, struct leh_tf_state
*tf
)
569 gimple_stmt_iterator gsi
= gsi_start (*seq
);
571 while (!gsi_end_p (gsi
))
572 replace_goto_queue_1 (gsi_stmt (gsi
), tf
, &gsi
);
575 /* Replace all goto queue members. */
578 replace_goto_queue (struct leh_tf_state
*tf
)
580 if (tf
->goto_queue_active
== 0)
582 replace_goto_queue_stmt_list (&tf
->top_p_seq
, tf
);
583 replace_goto_queue_stmt_list (&eh_seq
, tf
);
586 /* Add a new record to the goto queue contained in TF. NEW_STMT is the
587 data to be added, IS_LABEL indicates whether NEW_STMT is a label or
591 record_in_goto_queue (struct leh_tf_state
*tf
,
598 struct goto_queue_node
*q
;
600 gcc_assert (!tf
->goto_queue_map
);
602 active
= tf
->goto_queue_active
;
603 size
= tf
->goto_queue_size
;
606 size
= (size
? size
* 2 : 32);
607 tf
->goto_queue_size
= size
;
609 = XRESIZEVEC (struct goto_queue_node
, tf
->goto_queue
, size
);
612 q
= &tf
->goto_queue
[active
];
613 tf
->goto_queue_active
= active
+ 1;
615 memset (q
, 0, sizeof (*q
));
618 q
->location
= location
;
619 q
->is_label
= is_label
;
622 /* Record the LABEL label in the goto queue contained in TF.
626 record_in_goto_queue_label (struct leh_tf_state
*tf
, treemple stmt
, tree label
,
630 treemple temp
, new_stmt
;
635 /* Computed and non-local gotos do not get processed. Given
636 their nature we can neither tell whether we've escaped the
637 finally block nor redirect them if we knew. */
638 if (TREE_CODE (label
) != LABEL_DECL
)
641 /* No need to record gotos that don't leave the try block. */
643 if (!outside_finally_tree (temp
, tf
->try_finally_expr
))
646 if (! tf
->dest_array
.exists ())
648 tf
->dest_array
.create (10);
649 tf
->dest_array
.quick_push (label
);
654 int n
= tf
->dest_array
.length ();
655 for (index
= 0; index
< n
; ++index
)
656 if (tf
->dest_array
[index
] == label
)
659 tf
->dest_array
.safe_push (label
);
662 /* In the case of a GOTO we want to record the destination label,
663 since with a GIMPLE_COND we have an easy access to the then/else
666 record_in_goto_queue (tf
, new_stmt
, index
, true, location
);
669 /* For any GIMPLE_GOTO or GIMPLE_RETURN, decide whether it leaves a try_finally
670 node, and if so record that fact in the goto queue associated with that
674 maybe_record_in_goto_queue (struct leh_state
*state
, gimple stmt
)
676 struct leh_tf_state
*tf
= state
->tf
;
682 switch (gimple_code (stmt
))
685 new_stmt
.tp
= gimple_op_ptr (stmt
, 2);
686 record_in_goto_queue_label (tf
, new_stmt
, gimple_cond_true_label (stmt
),
687 EXPR_LOCATION (*new_stmt
.tp
));
688 new_stmt
.tp
= gimple_op_ptr (stmt
, 3);
689 record_in_goto_queue_label (tf
, new_stmt
, gimple_cond_false_label (stmt
),
690 EXPR_LOCATION (*new_stmt
.tp
));
694 record_in_goto_queue_label (tf
, new_stmt
, gimple_goto_dest (stmt
),
695 gimple_location (stmt
));
699 tf
->may_return
= true;
701 record_in_goto_queue (tf
, new_stmt
, -1, false, gimple_location (stmt
));
710 #ifdef ENABLE_CHECKING
711 /* We do not process GIMPLE_SWITCHes for now. As long as the original source
712 was in fact structured, and we've not yet done jump threading, then none
713 of the labels will leave outer GIMPLE_TRY_FINALLY nodes. Verify this. */
716 verify_norecord_switch_expr (struct leh_state
*state
, gimple switch_expr
)
718 struct leh_tf_state
*tf
= state
->tf
;
724 n
= gimple_switch_num_labels (switch_expr
);
726 for (i
= 0; i
< n
; ++i
)
729 tree lab
= CASE_LABEL (gimple_switch_label (switch_expr
, i
));
731 gcc_assert (!outside_finally_tree (temp
, tf
->try_finally_expr
));
735 #define verify_norecord_switch_expr(state, switch_expr)
738 /* Redirect a RETURN_EXPR pointed to by Q to FINLAB. If MOD is
739 non-null, insert it before the new branch. */
742 do_return_redirection (struct goto_queue_node
*q
, tree finlab
, gimple_seq mod
)
746 /* In the case of a return, the queue node must be a gimple statement. */
747 gcc_assert (!q
->is_label
);
749 /* Note that the return value may have already been computed, e.g.,
762 should return 0, not 1. We don't have to do anything to make
763 this happens because the return value has been placed in the
764 RESULT_DECL already. */
766 q
->cont_stmt
= q
->stmt
.g
;
769 gimple_seq_add_seq (&q
->repl_stmt
, mod
);
771 x
= gimple_build_goto (finlab
);
772 gimple_set_location (x
, q
->location
);
773 gimple_seq_add_stmt (&q
->repl_stmt
, x
);
776 /* Similar, but easier, for GIMPLE_GOTO. */
779 do_goto_redirection (struct goto_queue_node
*q
, tree finlab
, gimple_seq mod
,
780 struct leh_tf_state
*tf
)
784 gcc_assert (q
->is_label
);
786 q
->cont_stmt
= gimple_build_goto (tf
->dest_array
[q
->index
]);
789 gimple_seq_add_seq (&q
->repl_stmt
, mod
);
791 x
= gimple_build_goto (finlab
);
792 gimple_set_location (x
, q
->location
);
793 gimple_seq_add_stmt (&q
->repl_stmt
, x
);
796 /* Emit a standard landing pad sequence into SEQ for REGION. */
799 emit_post_landing_pad (gimple_seq
*seq
, eh_region region
)
801 eh_landing_pad lp
= region
->landing_pads
;
805 lp
= gen_eh_landing_pad (region
);
807 lp
->post_landing_pad
= create_artificial_label (UNKNOWN_LOCATION
);
808 EH_LANDING_PAD_NR (lp
->post_landing_pad
) = lp
->index
;
810 x
= gimple_build_label (lp
->post_landing_pad
);
811 gimple_seq_add_stmt (seq
, x
);
814 /* Emit a RESX statement into SEQ for REGION. */
817 emit_resx (gimple_seq
*seq
, eh_region region
)
819 gimple x
= gimple_build_resx (region
->index
);
820 gimple_seq_add_stmt (seq
, x
);
822 record_stmt_eh_region (region
->outer
, x
);
825 /* Emit an EH_DISPATCH statement into SEQ for REGION. */
828 emit_eh_dispatch (gimple_seq
*seq
, eh_region region
)
830 gimple x
= gimple_build_eh_dispatch (region
->index
);
831 gimple_seq_add_stmt (seq
, x
);
834 /* Note that the current EH region may contain a throw, or a
835 call to a function which itself may contain a throw. */
838 note_eh_region_may_contain_throw (eh_region region
)
840 while (bitmap_set_bit (eh_region_may_contain_throw_map
, region
->index
))
842 if (region
->type
== ERT_MUST_NOT_THROW
)
844 region
= region
->outer
;
850 /* Check if REGION has been marked as containing a throw. If REGION is
851 NULL, this predicate is false. */
854 eh_region_may_contain_throw (eh_region r
)
856 return r
&& bitmap_bit_p (eh_region_may_contain_throw_map
, r
->index
);
859 /* We want to transform
860 try { body; } catch { stuff; }
870 TP is a GIMPLE_TRY node. REGION is the region whose post_landing_pad
871 should be placed before the second operand, or NULL. OVER is
872 an existing label that should be put at the exit, or NULL. */
875 frob_into_branch_around (gimple tp
, eh_region region
, tree over
)
878 gimple_seq cleanup
, result
;
879 location_t loc
= gimple_location (tp
);
881 cleanup
= gimple_try_cleanup (tp
);
882 result
= gimple_try_eval (tp
);
885 emit_post_landing_pad (&eh_seq
, region
);
887 if (gimple_seq_may_fallthru (cleanup
))
890 over
= create_artificial_label (loc
);
891 x
= gimple_build_goto (over
);
892 gimple_set_location (x
, loc
);
893 gimple_seq_add_stmt (&cleanup
, x
);
895 gimple_seq_add_seq (&eh_seq
, cleanup
);
899 x
= gimple_build_label (over
);
900 gimple_seq_add_stmt (&result
, x
);
905 /* A subroutine of lower_try_finally. Duplicate the tree rooted at T.
906 Make sure to record all new labels found. */
909 lower_try_finally_dup_block (gimple_seq seq
, struct leh_state
*outer_state
,
912 gimple region
= NULL
;
914 gimple_stmt_iterator gsi
;
916 new_seq
= copy_gimple_seq_and_replace_locals (seq
);
918 for (gsi
= gsi_start (new_seq
); !gsi_end_p (gsi
); gsi_next (&gsi
))
920 gimple stmt
= gsi_stmt (gsi
);
921 if (LOCATION_LOCUS (gimple_location (stmt
)) == UNKNOWN_LOCATION
)
923 tree block
= gimple_block (stmt
);
924 gimple_set_location (stmt
, loc
);
925 gimple_set_block (stmt
, block
);
930 region
= outer_state
->tf
->try_finally_expr
;
931 collect_finally_tree_1 (new_seq
, region
);
936 /* A subroutine of lower_try_finally. Create a fallthru label for
937 the given try_finally state. The only tricky bit here is that
938 we have to make sure to record the label in our outer context. */
941 lower_try_finally_fallthru_label (struct leh_tf_state
*tf
)
943 tree label
= tf
->fallthru_label
;
948 label
= create_artificial_label (gimple_location (tf
->try_finally_expr
));
949 tf
->fallthru_label
= label
;
953 record_in_finally_tree (temp
, tf
->outer
->tf
->try_finally_expr
);
959 /* A subroutine of lower_try_finally. If FINALLY consits of a
960 GIMPLE_EH_ELSE node, return it. */
963 get_eh_else (gimple_seq finally
)
965 gimple x
= gimple_seq_first_stmt (finally
);
966 if (gimple_code (x
) == GIMPLE_EH_ELSE
)
968 gcc_assert (gimple_seq_singleton_p (finally
));
974 /* A subroutine of lower_try_finally. If the eh_protect_cleanup_actions
975 langhook returns non-null, then the language requires that the exception
976 path out of a try_finally be treated specially. To wit: the code within
977 the finally block may not itself throw an exception. We have two choices
978 here. First we can duplicate the finally block and wrap it in a
979 must_not_throw region. Second, we can generate code like
984 if (fintmp == eh_edge)
985 protect_cleanup_actions;
988 where "fintmp" is the temporary used in the switch statement generation
989 alternative considered below. For the nonce, we always choose the first
992 THIS_STATE may be null if this is a try-cleanup, not a try-finally. */
995 honor_protect_cleanup_actions (struct leh_state
*outer_state
,
996 struct leh_state
*this_state
,
997 struct leh_tf_state
*tf
)
999 tree protect_cleanup_actions
;
1000 gimple_stmt_iterator gsi
;
1001 bool finally_may_fallthru
;
1005 /* First check for nothing to do. */
1006 if (lang_hooks
.eh_protect_cleanup_actions
== NULL
)
1008 protect_cleanup_actions
= lang_hooks
.eh_protect_cleanup_actions ();
1009 if (protect_cleanup_actions
== NULL
)
1012 finally
= gimple_try_cleanup (tf
->top_p
);
1013 eh_else
= get_eh_else (finally
);
1015 /* Duplicate the FINALLY block. Only need to do this for try-finally,
1016 and not for cleanups. If we've got an EH_ELSE, extract it now. */
1019 finally
= gimple_eh_else_e_body (eh_else
);
1020 gimple_try_set_cleanup (tf
->top_p
, gimple_eh_else_n_body (eh_else
));
1022 else if (this_state
)
1023 finally
= lower_try_finally_dup_block (finally
, outer_state
,
1024 gimple_location (tf
->try_finally_expr
));
1025 finally_may_fallthru
= gimple_seq_may_fallthru (finally
);
1027 /* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP
1028 set, the handler of the TRY_CATCH_EXPR is another cleanup which ought
1029 to be in an enclosing scope, but needs to be implemented at this level
1030 to avoid a nesting violation (see wrap_temporary_cleanups in
1031 cp/decl.c). Since it's logically at an outer level, we should call
1032 terminate before we get to it, so strip it away before adding the
1033 MUST_NOT_THROW filter. */
1034 gsi
= gsi_start (finally
);
1036 if (gimple_code (x
) == GIMPLE_TRY
1037 && gimple_try_kind (x
) == GIMPLE_TRY_CATCH
1038 && gimple_try_catch_is_cleanup (x
))
1040 gsi_insert_seq_before (&gsi
, gimple_try_eval (x
), GSI_SAME_STMT
);
1041 gsi_remove (&gsi
, false);
1044 /* Wrap the block with protect_cleanup_actions as the action. */
1045 x
= gimple_build_eh_must_not_throw (protect_cleanup_actions
);
1046 x
= gimple_build_try (finally
, gimple_seq_alloc_with_stmt (x
),
1048 finally
= lower_eh_must_not_throw (outer_state
, x
);
1050 /* Drop all of this into the exception sequence. */
1051 emit_post_landing_pad (&eh_seq
, tf
->region
);
1052 gimple_seq_add_seq (&eh_seq
, finally
);
1053 if (finally_may_fallthru
)
1054 emit_resx (&eh_seq
, tf
->region
);
1056 /* Having now been handled, EH isn't to be considered with
1057 the rest of the outgoing edges. */
1058 tf
->may_throw
= false;
1061 /* A subroutine of lower_try_finally. We have determined that there is
1062 no fallthru edge out of the finally block. This means that there is
1063 no outgoing edge corresponding to any incoming edge. Restructure the
1064 try_finally node for this special case. */
1067 lower_try_finally_nofallthru (struct leh_state
*state
,
1068 struct leh_tf_state
*tf
)
1073 struct goto_queue_node
*q
, *qe
;
1075 lab
= create_artificial_label (gimple_location (tf
->try_finally_expr
));
1077 /* We expect that tf->top_p is a GIMPLE_TRY. */
1078 finally
= gimple_try_cleanup (tf
->top_p
);
1079 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1081 x
= gimple_build_label (lab
);
1082 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1085 qe
= q
+ tf
->goto_queue_active
;
1088 do_return_redirection (q
, lab
, NULL
);
1090 do_goto_redirection (q
, lab
, NULL
, tf
);
1092 replace_goto_queue (tf
);
1094 /* Emit the finally block into the stream. Lower EH_ELSE at this time. */
1095 eh_else
= get_eh_else (finally
);
1098 finally
= gimple_eh_else_n_body (eh_else
);
1099 lower_eh_constructs_1 (state
, &finally
);
1100 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1104 finally
= gimple_eh_else_e_body (eh_else
);
1105 lower_eh_constructs_1 (state
, &finally
);
1107 emit_post_landing_pad (&eh_seq
, tf
->region
);
1108 gimple_seq_add_seq (&eh_seq
, finally
);
1113 lower_eh_constructs_1 (state
, &finally
);
1114 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1118 emit_post_landing_pad (&eh_seq
, tf
->region
);
1120 x
= gimple_build_goto (lab
);
1121 gimple_set_location (x
, gimple_location (tf
->try_finally_expr
));
1122 gimple_seq_add_stmt (&eh_seq
, x
);
1127 /* A subroutine of lower_try_finally. We have determined that there is
1128 exactly one destination of the finally block. Restructure the
1129 try_finally node for this special case. */
1132 lower_try_finally_onedest (struct leh_state
*state
, struct leh_tf_state
*tf
)
1134 struct goto_queue_node
*q
, *qe
;
1137 gimple_stmt_iterator gsi
;
1139 location_t loc
= gimple_location (tf
->try_finally_expr
);
1141 finally
= gimple_try_cleanup (tf
->top_p
);
1142 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1144 /* Since there's only one destination, and the destination edge can only
1145 either be EH or non-EH, that implies that all of our incoming edges
1146 are of the same type. Therefore we can lower EH_ELSE immediately. */
1147 x
= get_eh_else (finally
);
1151 finally
= gimple_eh_else_e_body (x
);
1153 finally
= gimple_eh_else_n_body (x
);
1156 lower_eh_constructs_1 (state
, &finally
);
1158 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1160 gimple stmt
= gsi_stmt (gsi
);
1161 if (LOCATION_LOCUS (gimple_location (stmt
)) == UNKNOWN_LOCATION
)
1163 tree block
= gimple_block (stmt
);
1164 gimple_set_location (stmt
, gimple_location (tf
->try_finally_expr
));
1165 gimple_set_block (stmt
, block
);
1171 /* Only reachable via the exception edge. Add the given label to
1172 the head of the FINALLY block. Append a RESX at the end. */
1173 emit_post_landing_pad (&eh_seq
, tf
->region
);
1174 gimple_seq_add_seq (&eh_seq
, finally
);
1175 emit_resx (&eh_seq
, tf
->region
);
1179 if (tf
->may_fallthru
)
1181 /* Only reachable via the fallthru edge. Do nothing but let
1182 the two blocks run together; we'll fall out the bottom. */
1183 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1187 finally_label
= create_artificial_label (loc
);
1188 x
= gimple_build_label (finally_label
);
1189 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1191 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1194 qe
= q
+ tf
->goto_queue_active
;
1198 /* Reachable by return expressions only. Redirect them. */
1200 do_return_redirection (q
, finally_label
, NULL
);
1201 replace_goto_queue (tf
);
1205 /* Reachable by goto expressions only. Redirect them. */
1207 do_goto_redirection (q
, finally_label
, NULL
, tf
);
1208 replace_goto_queue (tf
);
1210 if (tf
->dest_array
[0] == tf
->fallthru_label
)
1212 /* Reachable by goto to fallthru label only. Redirect it
1213 to the new label (already created, sadly), and do not
1214 emit the final branch out, or the fallthru label. */
1215 tf
->fallthru_label
= NULL
;
1220 /* Place the original return/goto to the original destination
1221 immediately after the finally block. */
1222 x
= tf
->goto_queue
[0].cont_stmt
;
1223 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1224 maybe_record_in_goto_queue (state
, x
);
1227 /* A subroutine of lower_try_finally. There are multiple edges incoming
1228 and outgoing from the finally block. Implement this by duplicating the
1229 finally block for every destination. */
1232 lower_try_finally_copy (struct leh_state
*state
, struct leh_tf_state
*tf
)
1235 gimple_seq new_stmt
;
1239 location_t tf_loc
= gimple_location (tf
->try_finally_expr
);
1241 finally
= gimple_try_cleanup (tf
->top_p
);
1243 /* Notice EH_ELSE, and simplify some of the remaining code
1244 by considering FINALLY to be the normal return path only. */
1245 eh_else
= get_eh_else (finally
);
1247 finally
= gimple_eh_else_n_body (eh_else
);
1249 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1252 if (tf
->may_fallthru
)
1254 seq
= lower_try_finally_dup_block (finally
, state
, tf_loc
);
1255 lower_eh_constructs_1 (state
, &seq
);
1256 gimple_seq_add_seq (&new_stmt
, seq
);
1258 tmp
= lower_try_finally_fallthru_label (tf
);
1259 x
= gimple_build_goto (tmp
);
1260 gimple_set_location (x
, tf_loc
);
1261 gimple_seq_add_stmt (&new_stmt
, x
);
1266 /* We don't need to copy the EH path of EH_ELSE,
1267 since it is only emitted once. */
1269 seq
= gimple_eh_else_e_body (eh_else
);
1271 seq
= lower_try_finally_dup_block (finally
, state
, tf_loc
);
1272 lower_eh_constructs_1 (state
, &seq
);
1274 emit_post_landing_pad (&eh_seq
, tf
->region
);
1275 gimple_seq_add_seq (&eh_seq
, seq
);
1276 emit_resx (&eh_seq
, tf
->region
);
1281 struct goto_queue_node
*q
, *qe
;
1282 int return_index
, index
;
1285 struct goto_queue_node
*q
;
1289 return_index
= tf
->dest_array
.length ();
1290 labels
= XCNEWVEC (struct labels_s
, return_index
+ 1);
1293 qe
= q
+ tf
->goto_queue_active
;
1296 index
= q
->index
< 0 ? return_index
: q
->index
;
1298 if (!labels
[index
].q
)
1299 labels
[index
].q
= q
;
1302 for (index
= 0; index
< return_index
+ 1; index
++)
1306 q
= labels
[index
].q
;
1310 lab
= labels
[index
].label
1311 = create_artificial_label (tf_loc
);
1313 if (index
== return_index
)
1314 do_return_redirection (q
, lab
, NULL
);
1316 do_goto_redirection (q
, lab
, NULL
, tf
);
1318 x
= gimple_build_label (lab
);
1319 gimple_seq_add_stmt (&new_stmt
, x
);
1321 seq
= lower_try_finally_dup_block (finally
, state
, q
->location
);
1322 lower_eh_constructs_1 (state
, &seq
);
1323 gimple_seq_add_seq (&new_stmt
, seq
);
1325 gimple_seq_add_stmt (&new_stmt
, q
->cont_stmt
);
1326 maybe_record_in_goto_queue (state
, q
->cont_stmt
);
1329 for (q
= tf
->goto_queue
; q
< qe
; q
++)
1333 index
= q
->index
< 0 ? return_index
: q
->index
;
1335 if (labels
[index
].q
== q
)
1338 lab
= labels
[index
].label
;
1340 if (index
== return_index
)
1341 do_return_redirection (q
, lab
, NULL
);
1343 do_goto_redirection (q
, lab
, NULL
, tf
);
1346 replace_goto_queue (tf
);
1350 /* Need to link new stmts after running replace_goto_queue due
1351 to not wanting to process the same goto stmts twice. */
1352 gimple_seq_add_seq (&tf
->top_p_seq
, new_stmt
);
1355 /* A subroutine of lower_try_finally. There are multiple edges incoming
1356 and outgoing from the finally block. Implement this by instrumenting
1357 each incoming edge and creating a switch statement at the end of the
1358 finally block that branches to the appropriate destination. */
1361 lower_try_finally_switch (struct leh_state
*state
, struct leh_tf_state
*tf
)
1363 struct goto_queue_node
*q
, *qe
;
1364 tree finally_tmp
, finally_label
;
1365 int return_index
, eh_index
, fallthru_index
;
1366 int nlabels
, ndests
, j
, last_case_index
;
1368 vec
<tree
> case_label_vec
;
1369 gimple_seq switch_body
= NULL
;
1374 struct pointer_map_t
*cont_map
= NULL
;
1375 /* The location of the TRY_FINALLY stmt. */
1376 location_t tf_loc
= gimple_location (tf
->try_finally_expr
);
1377 /* The location of the finally block. */
1378 location_t finally_loc
;
1380 finally
= gimple_try_cleanup (tf
->top_p
);
1381 eh_else
= get_eh_else (finally
);
1383 /* Mash the TRY block to the head of the chain. */
1384 tf
->top_p_seq
= gimple_try_eval (tf
->top_p
);
1386 /* The location of the finally is either the last stmt in the finally
1387 block or the location of the TRY_FINALLY itself. */
1388 x
= gimple_seq_last_stmt (finally
);
1389 finally_loc
= x
? gimple_location (x
) : tf_loc
;
1391 /* Prepare for switch statement generation. */
1392 nlabels
= tf
->dest_array
.length ();
1393 return_index
= nlabels
;
1394 eh_index
= return_index
+ tf
->may_return
;
1395 fallthru_index
= eh_index
+ (tf
->may_throw
&& !eh_else
);
1396 ndests
= fallthru_index
+ tf
->may_fallthru
;
1398 finally_tmp
= create_tmp_var (integer_type_node
, "finally_tmp");
1399 finally_label
= create_artificial_label (finally_loc
);
1401 /* We use vec::quick_push on case_label_vec throughout this function,
1402 since we know the size in advance and allocate precisely as muce
1404 case_label_vec
.create (ndests
);
1406 last_case_index
= 0;
1408 /* Begin inserting code for getting to the finally block. Things
1409 are done in this order to correspond to the sequence the code is
1412 if (tf
->may_fallthru
)
1414 x
= gimple_build_assign (finally_tmp
,
1415 build_int_cst (integer_type_node
,
1417 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1419 tmp
= build_int_cst (integer_type_node
, fallthru_index
);
1420 last_case
= build_case_label (tmp
, NULL
,
1421 create_artificial_label (tf_loc
));
1422 case_label_vec
.quick_push (last_case
);
1425 x
= gimple_build_label (CASE_LABEL (last_case
));
1426 gimple_seq_add_stmt (&switch_body
, x
);
1428 tmp
= lower_try_finally_fallthru_label (tf
);
1429 x
= gimple_build_goto (tmp
);
1430 gimple_set_location (x
, tf_loc
);
1431 gimple_seq_add_stmt (&switch_body
, x
);
1434 /* For EH_ELSE, emit the exception path (plus resx) now, then
1435 subsequently we only need consider the normal path. */
1440 finally
= gimple_eh_else_e_body (eh_else
);
1441 lower_eh_constructs_1 (state
, &finally
);
1443 emit_post_landing_pad (&eh_seq
, tf
->region
);
1444 gimple_seq_add_seq (&eh_seq
, finally
);
1445 emit_resx (&eh_seq
, tf
->region
);
1448 finally
= gimple_eh_else_n_body (eh_else
);
1450 else if (tf
->may_throw
)
1452 emit_post_landing_pad (&eh_seq
, tf
->region
);
1454 x
= gimple_build_assign (finally_tmp
,
1455 build_int_cst (integer_type_node
, eh_index
));
1456 gimple_seq_add_stmt (&eh_seq
, x
);
1458 x
= gimple_build_goto (finally_label
);
1459 gimple_set_location (x
, tf_loc
);
1460 gimple_seq_add_stmt (&eh_seq
, x
);
1462 tmp
= build_int_cst (integer_type_node
, eh_index
);
1463 last_case
= build_case_label (tmp
, NULL
,
1464 create_artificial_label (tf_loc
));
1465 case_label_vec
.quick_push (last_case
);
1468 x
= gimple_build_label (CASE_LABEL (last_case
));
1469 gimple_seq_add_stmt (&eh_seq
, x
);
1470 emit_resx (&eh_seq
, tf
->region
);
1473 x
= gimple_build_label (finally_label
);
1474 gimple_seq_add_stmt (&tf
->top_p_seq
, x
);
1476 lower_eh_constructs_1 (state
, &finally
);
1477 gimple_seq_add_seq (&tf
->top_p_seq
, finally
);
1479 /* Redirect each incoming goto edge. */
1481 qe
= q
+ tf
->goto_queue_active
;
1482 j
= last_case_index
+ tf
->may_return
;
1483 /* Prepare the assignments to finally_tmp that are executed upon the
1484 entrance through a particular edge. */
1487 gimple_seq mod
= NULL
;
1489 unsigned int case_index
;
1493 x
= gimple_build_assign (finally_tmp
,
1494 build_int_cst (integer_type_node
,
1496 gimple_seq_add_stmt (&mod
, x
);
1497 do_return_redirection (q
, finally_label
, mod
);
1498 switch_id
= return_index
;
1502 x
= gimple_build_assign (finally_tmp
,
1503 build_int_cst (integer_type_node
, q
->index
));
1504 gimple_seq_add_stmt (&mod
, x
);
1505 do_goto_redirection (q
, finally_label
, mod
, tf
);
1506 switch_id
= q
->index
;
1509 case_index
= j
+ q
->index
;
1510 if (case_label_vec
.length () <= case_index
|| !case_label_vec
[case_index
])
1514 tmp
= build_int_cst (integer_type_node
, switch_id
);
1515 case_lab
= build_case_label (tmp
, NULL
,
1516 create_artificial_label (tf_loc
));
1517 /* We store the cont_stmt in the pointer map, so that we can recover
1518 it in the loop below. */
1520 cont_map
= pointer_map_create ();
1521 slot
= pointer_map_insert (cont_map
, case_lab
);
1522 *slot
= q
->cont_stmt
;
1523 case_label_vec
.quick_push (case_lab
);
1526 for (j
= last_case_index
; j
< last_case_index
+ nlabels
; j
++)
1531 last_case
= case_label_vec
[j
];
1533 gcc_assert (last_case
);
1534 gcc_assert (cont_map
);
1536 slot
= pointer_map_contains (cont_map
, last_case
);
1538 cont_stmt
= *(gimple
*) slot
;
1540 x
= gimple_build_label (CASE_LABEL (last_case
));
1541 gimple_seq_add_stmt (&switch_body
, x
);
1542 gimple_seq_add_stmt (&switch_body
, cont_stmt
);
1543 maybe_record_in_goto_queue (state
, cont_stmt
);
1546 pointer_map_destroy (cont_map
);
1548 replace_goto_queue (tf
);
1550 /* Make sure that the last case is the default label, as one is required.
1551 Then sort the labels, which is also required in GIMPLE. */
1552 CASE_LOW (last_case
) = NULL
;
1553 tree tem
= case_label_vec
.pop ();
1554 gcc_assert (tem
== last_case
);
1555 sort_case_labels (case_label_vec
);
1557 /* Build the switch statement, setting last_case to be the default
1559 switch_stmt
= gimple_build_switch (finally_tmp
, last_case
,
1561 gimple_set_location (switch_stmt
, finally_loc
);
1563 /* Need to link SWITCH_STMT after running replace_goto_queue
1564 due to not wanting to process the same goto stmts twice. */
1565 gimple_seq_add_stmt (&tf
->top_p_seq
, switch_stmt
);
1566 gimple_seq_add_seq (&tf
->top_p_seq
, switch_body
);
1569 /* Decide whether or not we are going to duplicate the finally block.
1570 There are several considerations.
1572 First, if this is Java, then the finally block contains code
1573 written by the user. It has line numbers associated with it,
1574 so duplicating the block means it's difficult to set a breakpoint.
1575 Since controlling code generation via -g is verboten, we simply
1576 never duplicate code without optimization.
1578 Second, we'd like to prevent egregious code growth. One way to
1579 do this is to estimate the size of the finally block, multiply
1580 that by the number of copies we'd need to make, and compare against
1581 the estimate of the size of the switch machinery we'd have to add. */
1584 decide_copy_try_finally (int ndests
, bool may_throw
, gimple_seq finally
)
1586 int f_estimate
, sw_estimate
;
1589 /* If there's an EH_ELSE involved, the exception path is separate
1590 and really doesn't come into play for this computation. */
1591 eh_else
= get_eh_else (finally
);
1594 ndests
-= may_throw
;
1595 finally
= gimple_eh_else_n_body (eh_else
);
1600 gimple_stmt_iterator gsi
;
1605 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1607 gimple stmt
= gsi_stmt (gsi
);
1608 if (!is_gimple_debug (stmt
) && !gimple_clobber_p (stmt
))
1614 /* Finally estimate N times, plus N gotos. */
1615 f_estimate
= count_insns_seq (finally
, &eni_size_weights
);
1616 f_estimate
= (f_estimate
+ 1) * ndests
;
1618 /* Switch statement (cost 10), N variable assignments, N gotos. */
1619 sw_estimate
= 10 + 2 * ndests
;
1621 /* Optimize for size clearly wants our best guess. */
1622 if (optimize_function_for_size_p (cfun
))
1623 return f_estimate
< sw_estimate
;
1625 /* ??? These numbers are completely made up so far. */
1627 return f_estimate
< 100 || f_estimate
< sw_estimate
* 2;
1629 return f_estimate
< 40 || f_estimate
* 2 < sw_estimate
* 3;
1632 /* REG is the enclosing region for a possible cleanup region, or the region
1633 itself. Returns TRUE if such a region would be unreachable.
1635 Cleanup regions within a must-not-throw region aren't actually reachable
1636 even if there are throwing stmts within them, because the personality
1637 routine will call terminate before unwinding. */
1640 cleanup_is_dead_in (eh_region reg
)
1642 while (reg
&& reg
->type
== ERT_CLEANUP
)
1644 return (reg
&& reg
->type
== ERT_MUST_NOT_THROW
);
1647 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_FINALLY nodes
1648 to a sequence of labels and blocks, plus the exception region trees
1649 that record all the magic. This is complicated by the need to
1650 arrange for the FINALLY block to be executed on all exits. */
1653 lower_try_finally (struct leh_state
*state
, gimple tp
)
1655 struct leh_tf_state this_tf
;
1656 struct leh_state this_state
;
1658 gimple_seq old_eh_seq
;
1660 /* Process the try block. */
1662 memset (&this_tf
, 0, sizeof (this_tf
));
1663 this_tf
.try_finally_expr
= tp
;
1665 this_tf
.outer
= state
;
1666 if (using_eh_for_cleanups_p () && !cleanup_is_dead_in (state
->cur_region
))
1668 this_tf
.region
= gen_eh_region_cleanup (state
->cur_region
);
1669 this_state
.cur_region
= this_tf
.region
;
1673 this_tf
.region
= NULL
;
1674 this_state
.cur_region
= state
->cur_region
;
1677 this_state
.ehp_region
= state
->ehp_region
;
1678 this_state
.tf
= &this_tf
;
1680 old_eh_seq
= eh_seq
;
1683 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1685 /* Determine if the try block is escaped through the bottom. */
1686 this_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1688 /* Determine if any exceptions are possible within the try block. */
1690 this_tf
.may_throw
= eh_region_may_contain_throw (this_tf
.region
);
1691 if (this_tf
.may_throw
)
1692 honor_protect_cleanup_actions (state
, &this_state
, &this_tf
);
1694 /* Determine how many edges (still) reach the finally block. Or rather,
1695 how many destinations are reached by the finally block. Use this to
1696 determine how we process the finally block itself. */
1698 ndests
= this_tf
.dest_array
.length ();
1699 ndests
+= this_tf
.may_fallthru
;
1700 ndests
+= this_tf
.may_return
;
1701 ndests
+= this_tf
.may_throw
;
1703 /* If the FINALLY block is not reachable, dike it out. */
1706 gimple_seq_add_seq (&this_tf
.top_p_seq
, gimple_try_eval (tp
));
1707 gimple_try_set_cleanup (tp
, NULL
);
1709 /* If the finally block doesn't fall through, then any destination
1710 we might try to impose there isn't reached either. There may be
1711 some minor amount of cleanup and redirection still needed. */
1712 else if (!gimple_seq_may_fallthru (gimple_try_cleanup (tp
)))
1713 lower_try_finally_nofallthru (state
, &this_tf
);
1715 /* We can easily special-case redirection to a single destination. */
1716 else if (ndests
== 1)
1717 lower_try_finally_onedest (state
, &this_tf
);
1718 else if (decide_copy_try_finally (ndests
, this_tf
.may_throw
,
1719 gimple_try_cleanup (tp
)))
1720 lower_try_finally_copy (state
, &this_tf
);
1722 lower_try_finally_switch (state
, &this_tf
);
1724 /* If someone requested we add a label at the end of the transformed
1726 if (this_tf
.fallthru_label
)
1728 /* This must be reached only if ndests == 0. */
1729 gimple x
= gimple_build_label (this_tf
.fallthru_label
);
1730 gimple_seq_add_stmt (&this_tf
.top_p_seq
, x
);
1733 this_tf
.dest_array
.release ();
1734 free (this_tf
.goto_queue
);
1735 if (this_tf
.goto_queue_map
)
1736 pointer_map_destroy (this_tf
.goto_queue_map
);
1738 /* If there was an old (aka outer) eh_seq, append the current eh_seq.
1739 If there was no old eh_seq, then the append is trivially already done. */
1743 eh_seq
= old_eh_seq
;
1746 gimple_seq new_eh_seq
= eh_seq
;
1747 eh_seq
= old_eh_seq
;
1748 gimple_seq_add_seq (&eh_seq
, new_eh_seq
);
1752 return this_tf
.top_p_seq
;
1755 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_CATCH with a
1756 list of GIMPLE_CATCH to a sequence of labels and blocks, plus the
1757 exception region trees that records all the magic. */
1760 lower_catch (struct leh_state
*state
, gimple tp
)
1762 eh_region try_region
= NULL
;
1763 struct leh_state this_state
= *state
;
1764 gimple_stmt_iterator gsi
;
1766 gimple_seq new_seq
, cleanup
;
1768 location_t try_catch_loc
= gimple_location (tp
);
1770 if (flag_exceptions
)
1772 try_region
= gen_eh_region_try (state
->cur_region
);
1773 this_state
.cur_region
= try_region
;
1776 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1778 if (!eh_region_may_contain_throw (try_region
))
1779 return gimple_try_eval (tp
);
1782 emit_eh_dispatch (&new_seq
, try_region
);
1783 emit_resx (&new_seq
, try_region
);
1785 this_state
.cur_region
= state
->cur_region
;
1786 this_state
.ehp_region
= try_region
;
1789 cleanup
= gimple_try_cleanup (tp
);
1790 for (gsi
= gsi_start (cleanup
);
1798 gcatch
= gsi_stmt (gsi
);
1799 c
= gen_eh_region_catch (try_region
, gimple_catch_types (gcatch
));
1801 handler
= gimple_catch_handler (gcatch
);
1802 lower_eh_constructs_1 (&this_state
, &handler
);
1804 c
->label
= create_artificial_label (UNKNOWN_LOCATION
);
1805 x
= gimple_build_label (c
->label
);
1806 gimple_seq_add_stmt (&new_seq
, x
);
1808 gimple_seq_add_seq (&new_seq
, handler
);
1810 if (gimple_seq_may_fallthru (new_seq
))
1813 out_label
= create_artificial_label (try_catch_loc
);
1815 x
= gimple_build_goto (out_label
);
1816 gimple_seq_add_stmt (&new_seq
, x
);
1822 gimple_try_set_cleanup (tp
, new_seq
);
1824 return frob_into_branch_around (tp
, try_region
, out_label
);
1827 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with a
1828 GIMPLE_EH_FILTER to a sequence of labels and blocks, plus the exception
1829 region trees that record all the magic. */
1832 lower_eh_filter (struct leh_state
*state
, gimple tp
)
1834 struct leh_state this_state
= *state
;
1835 eh_region this_region
= NULL
;
1839 inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1841 if (flag_exceptions
)
1843 this_region
= gen_eh_region_allowed (state
->cur_region
,
1844 gimple_eh_filter_types (inner
));
1845 this_state
.cur_region
= this_region
;
1848 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1850 if (!eh_region_may_contain_throw (this_region
))
1851 return gimple_try_eval (tp
);
1854 this_state
.cur_region
= state
->cur_region
;
1855 this_state
.ehp_region
= this_region
;
1857 emit_eh_dispatch (&new_seq
, this_region
);
1858 emit_resx (&new_seq
, this_region
);
1860 this_region
->u
.allowed
.label
= create_artificial_label (UNKNOWN_LOCATION
);
1861 x
= gimple_build_label (this_region
->u
.allowed
.label
);
1862 gimple_seq_add_stmt (&new_seq
, x
);
1864 lower_eh_constructs_1 (&this_state
, gimple_eh_filter_failure_ptr (inner
));
1865 gimple_seq_add_seq (&new_seq
, gimple_eh_filter_failure (inner
));
1867 gimple_try_set_cleanup (tp
, new_seq
);
1869 return frob_into_branch_around (tp
, this_region
, NULL
);
1872 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with
1873 an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks,
1874 plus the exception region trees that record all the magic. */
1877 lower_eh_must_not_throw (struct leh_state
*state
, gimple tp
)
1879 struct leh_state this_state
= *state
;
1881 if (flag_exceptions
)
1883 gimple inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1884 eh_region this_region
;
1886 this_region
= gen_eh_region_must_not_throw (state
->cur_region
);
1887 this_region
->u
.must_not_throw
.failure_decl
1888 = gimple_eh_must_not_throw_fndecl (inner
);
1889 this_region
->u
.must_not_throw
.failure_loc
1890 = LOCATION_LOCUS (gimple_location (tp
));
1892 /* In order to get mangling applied to this decl, we must mark it
1893 used now. Otherwise, pass_ipa_free_lang_data won't think it
1895 TREE_USED (this_region
->u
.must_not_throw
.failure_decl
) = 1;
1897 this_state
.cur_region
= this_region
;
1900 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1902 return gimple_try_eval (tp
);
1905 /* Implement a cleanup expression. This is similar to try-finally,
1906 except that we only execute the cleanup block for exception edges. */
1909 lower_cleanup (struct leh_state
*state
, gimple tp
)
1911 struct leh_state this_state
= *state
;
1912 eh_region this_region
= NULL
;
1913 struct leh_tf_state fake_tf
;
1915 bool cleanup_dead
= cleanup_is_dead_in (state
->cur_region
);
1917 if (flag_exceptions
&& !cleanup_dead
)
1919 this_region
= gen_eh_region_cleanup (state
->cur_region
);
1920 this_state
.cur_region
= this_region
;
1923 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1925 if (cleanup_dead
|| !eh_region_may_contain_throw (this_region
))
1926 return gimple_try_eval (tp
);
1928 /* Build enough of a try-finally state so that we can reuse
1929 honor_protect_cleanup_actions. */
1930 memset (&fake_tf
, 0, sizeof (fake_tf
));
1931 fake_tf
.top_p
= fake_tf
.try_finally_expr
= tp
;
1932 fake_tf
.outer
= state
;
1933 fake_tf
.region
= this_region
;
1934 fake_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1935 fake_tf
.may_throw
= true;
1937 honor_protect_cleanup_actions (state
, NULL
, &fake_tf
);
1939 if (fake_tf
.may_throw
)
1941 /* In this case honor_protect_cleanup_actions had nothing to do,
1942 and we should process this normally. */
1943 lower_eh_constructs_1 (state
, gimple_try_cleanup_ptr (tp
));
1944 result
= frob_into_branch_around (tp
, this_region
,
1945 fake_tf
.fallthru_label
);
1949 /* In this case honor_protect_cleanup_actions did nearly all of
1950 the work. All we have left is to append the fallthru_label. */
1952 result
= gimple_try_eval (tp
);
1953 if (fake_tf
.fallthru_label
)
1955 gimple x
= gimple_build_label (fake_tf
.fallthru_label
);
1956 gimple_seq_add_stmt (&result
, x
);
1962 /* Main loop for lowering eh constructs. Also moves gsi to the next
1966 lower_eh_constructs_2 (struct leh_state
*state
, gimple_stmt_iterator
*gsi
)
1970 gimple stmt
= gsi_stmt (*gsi
);
1972 switch (gimple_code (stmt
))
1976 tree fndecl
= gimple_call_fndecl (stmt
);
1979 if (fndecl
&& DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
1980 switch (DECL_FUNCTION_CODE (fndecl
))
1982 case BUILT_IN_EH_POINTER
:
1983 /* The front end may have generated a call to
1984 __builtin_eh_pointer (0) within a catch region. Replace
1985 this zero argument with the current catch region number. */
1986 if (state
->ehp_region
)
1988 tree nr
= build_int_cst (integer_type_node
,
1989 state
->ehp_region
->index
);
1990 gimple_call_set_arg (stmt
, 0, nr
);
1994 /* The user has dome something silly. Remove it. */
1995 rhs
= null_pointer_node
;
2000 case BUILT_IN_EH_FILTER
:
2001 /* ??? This should never appear, but since it's a builtin it
2002 is accessible to abuse by users. Just remove it and
2003 replace the use with the arbitrary value zero. */
2004 rhs
= build_int_cst (TREE_TYPE (TREE_TYPE (fndecl
)), 0);
2006 lhs
= gimple_call_lhs (stmt
);
2007 x
= gimple_build_assign (lhs
, rhs
);
2008 gsi_insert_before (gsi
, x
, GSI_SAME_STMT
);
2011 case BUILT_IN_EH_COPY_VALUES
:
2012 /* Likewise this should not appear. Remove it. */
2013 gsi_remove (gsi
, true);
2023 /* If the stmt can throw use a new temporary for the assignment
2024 to a LHS. This makes sure the old value of the LHS is
2025 available on the EH edge. Only do so for statements that
2026 potentially fall through (no noreturn calls e.g.), otherwise
2027 this new assignment might create fake fallthru regions. */
2028 if (stmt_could_throw_p (stmt
)
2029 && gimple_has_lhs (stmt
)
2030 && gimple_stmt_may_fallthru (stmt
)
2031 && !tree_could_throw_p (gimple_get_lhs (stmt
))
2032 && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt
))))
2034 tree lhs
= gimple_get_lhs (stmt
);
2035 tree tmp
= create_tmp_var (TREE_TYPE (lhs
), NULL
);
2036 gimple s
= gimple_build_assign (lhs
, tmp
);
2037 gimple_set_location (s
, gimple_location (stmt
));
2038 gimple_set_block (s
, gimple_block (stmt
));
2039 gimple_set_lhs (stmt
, tmp
);
2040 if (TREE_CODE (TREE_TYPE (tmp
)) == COMPLEX_TYPE
2041 || TREE_CODE (TREE_TYPE (tmp
)) == VECTOR_TYPE
)
2042 DECL_GIMPLE_REG_P (tmp
) = 1;
2043 gsi_insert_after (gsi
, s
, GSI_SAME_STMT
);
2045 /* Look for things that can throw exceptions, and record them. */
2046 if (state
->cur_region
&& stmt_could_throw_p (stmt
))
2048 record_stmt_eh_region (state
->cur_region
, stmt
);
2049 note_eh_region_may_contain_throw (state
->cur_region
);
2056 maybe_record_in_goto_queue (state
, stmt
);
2060 verify_norecord_switch_expr (state
, stmt
);
2064 if (gimple_try_kind (stmt
) == GIMPLE_TRY_FINALLY
)
2065 replace
= lower_try_finally (state
, stmt
);
2068 x
= gimple_seq_first_stmt (gimple_try_cleanup (stmt
));
2071 replace
= gimple_try_eval (stmt
);
2072 lower_eh_constructs_1 (state
, &replace
);
2075 switch (gimple_code (x
))
2078 replace
= lower_catch (state
, stmt
);
2080 case GIMPLE_EH_FILTER
:
2081 replace
= lower_eh_filter (state
, stmt
);
2083 case GIMPLE_EH_MUST_NOT_THROW
:
2084 replace
= lower_eh_must_not_throw (state
, stmt
);
2086 case GIMPLE_EH_ELSE
:
2087 /* This code is only valid with GIMPLE_TRY_FINALLY. */
2090 replace
= lower_cleanup (state
, stmt
);
2095 /* Remove the old stmt and insert the transformed sequence
2097 gsi_insert_seq_before (gsi
, replace
, GSI_SAME_STMT
);
2098 gsi_remove (gsi
, true);
2100 /* Return since we don't want gsi_next () */
2103 case GIMPLE_EH_ELSE
:
2104 /* We should be eliminating this in lower_try_finally et al. */
2108 /* A type, a decl, or some kind of statement that we're not
2109 interested in. Don't walk them. */
2116 /* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */
2119 lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*pseq
)
2121 gimple_stmt_iterator gsi
;
2122 for (gsi
= gsi_start (*pseq
); !gsi_end_p (gsi
);)
2123 lower_eh_constructs_2 (state
, &gsi
);
2128 const pass_data pass_data_lower_eh
=
2130 GIMPLE_PASS
, /* type */
2132 OPTGROUP_NONE
, /* optinfo_flags */
2133 true, /* has_execute */
2134 TV_TREE_EH
, /* tv_id */
2135 PROP_gimple_lcf
, /* properties_required */
2136 PROP_gimple_leh
, /* properties_provided */
2137 0, /* properties_destroyed */
2138 0, /* todo_flags_start */
2139 0, /* todo_flags_finish */
2142 class pass_lower_eh
: public gimple_opt_pass
2145 pass_lower_eh (gcc::context
*ctxt
)
2146 : gimple_opt_pass (pass_data_lower_eh
, ctxt
)
2149 /* opt_pass methods: */
2150 virtual unsigned int execute (function
*);
2152 }; // class pass_lower_eh
2155 pass_lower_eh::execute (function
*fun
)
2157 struct leh_state null_state
;
2160 bodyp
= gimple_body (current_function_decl
);
2164 finally_tree
= new hash_table
<finally_tree_hasher
> (31);
2165 eh_region_may_contain_throw_map
= BITMAP_ALLOC (NULL
);
2166 memset (&null_state
, 0, sizeof (null_state
));
2168 collect_finally_tree_1 (bodyp
, NULL
);
2169 lower_eh_constructs_1 (&null_state
, &bodyp
);
2170 gimple_set_body (current_function_decl
, bodyp
);
2172 /* We assume there's a return statement, or something, at the end of
2173 the function, and thus ploping the EH sequence afterward won't
2175 gcc_assert (!gimple_seq_may_fallthru (bodyp
));
2176 gimple_seq_add_seq (&bodyp
, eh_seq
);
2178 /* We assume that since BODYP already existed, adding EH_SEQ to it
2179 didn't change its value, and we don't have to re-set the function. */
2180 gcc_assert (bodyp
== gimple_body (current_function_decl
));
2182 delete finally_tree
;
2183 finally_tree
= NULL
;
2184 BITMAP_FREE (eh_region_may_contain_throw_map
);
2187 /* If this function needs a language specific EH personality routine
2188 and the frontend didn't already set one do so now. */
2189 if (function_needs_eh_personality (fun
) == eh_personality_lang
2190 && !DECL_FUNCTION_PERSONALITY (current_function_decl
))
2191 DECL_FUNCTION_PERSONALITY (current_function_decl
)
2192 = lang_hooks
.eh_personality ();
2200 make_pass_lower_eh (gcc::context
*ctxt
)
2202 return new pass_lower_eh (ctxt
);
2205 /* Create the multiple edges from an EH_DISPATCH statement to all of
2206 the possible handlers for its EH region. Return true if there's
2207 no fallthru edge; false if there is. */
2210 make_eh_dispatch_edges (gimple stmt
)
2214 basic_block src
, dst
;
2216 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2217 src
= gimple_bb (stmt
);
2222 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2224 dst
= label_to_block (c
->label
);
2225 make_edge (src
, dst
, 0);
2227 /* A catch-all handler doesn't have a fallthru. */
2228 if (c
->type_list
== NULL
)
2233 case ERT_ALLOWED_EXCEPTIONS
:
2234 dst
= label_to_block (r
->u
.allowed
.label
);
2235 make_edge (src
, dst
, 0);
2245 /* Create the single EH edge from STMT to its nearest landing pad,
2246 if there is such a landing pad within the current function. */
2249 make_eh_edges (gimple stmt
)
2251 basic_block src
, dst
;
2255 lp_nr
= lookup_stmt_eh_lp (stmt
);
2259 lp
= get_eh_landing_pad_from_number (lp_nr
);
2260 gcc_assert (lp
!= NULL
);
2262 src
= gimple_bb (stmt
);
2263 dst
= label_to_block (lp
->post_landing_pad
);
2264 make_edge (src
, dst
, EDGE_EH
);
2267 /* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
2268 do not actually perform the final edge redirection.
2270 CHANGE_REGION is true when we're being called from cleanup_empty_eh and
2271 we intend to change the destination EH region as well; this means
2272 EH_LANDING_PAD_NR must already be set on the destination block label.
2273 If false, we're being called from generic cfg manipulation code and we
2274 should preserve our place within the region tree. */
2277 redirect_eh_edge_1 (edge edge_in
, basic_block new_bb
, bool change_region
)
2279 eh_landing_pad old_lp
, new_lp
;
2282 int old_lp_nr
, new_lp_nr
;
2283 tree old_label
, new_label
;
2287 old_bb
= edge_in
->dest
;
2288 old_label
= gimple_block_label (old_bb
);
2289 old_lp_nr
= EH_LANDING_PAD_NR (old_label
);
2290 gcc_assert (old_lp_nr
> 0);
2291 old_lp
= get_eh_landing_pad_from_number (old_lp_nr
);
2293 throw_stmt
= last_stmt (edge_in
->src
);
2294 gcc_assert (lookup_stmt_eh_lp (throw_stmt
) == old_lp_nr
);
2296 new_label
= gimple_block_label (new_bb
);
2298 /* Look for an existing region that might be using NEW_BB already. */
2299 new_lp_nr
= EH_LANDING_PAD_NR (new_label
);
2302 new_lp
= get_eh_landing_pad_from_number (new_lp_nr
);
2303 gcc_assert (new_lp
);
2305 /* Unless CHANGE_REGION is true, the new and old landing pad
2306 had better be associated with the same EH region. */
2307 gcc_assert (change_region
|| new_lp
->region
== old_lp
->region
);
2312 gcc_assert (!change_region
);
2315 /* Notice when we redirect the last EH edge away from OLD_BB. */
2316 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
2317 if (e
!= edge_in
&& (e
->flags
& EDGE_EH
))
2322 /* NEW_LP already exists. If there are still edges into OLD_LP,
2323 there's nothing to do with the EH tree. If there are no more
2324 edges into OLD_LP, then we want to remove OLD_LP as it is unused.
2325 If CHANGE_REGION is true, then our caller is expecting to remove
2327 if (e
== NULL
&& !change_region
)
2328 remove_eh_landing_pad (old_lp
);
2332 /* No correct landing pad exists. If there are no more edges
2333 into OLD_LP, then we can simply re-use the existing landing pad.
2334 Otherwise, we have to create a new landing pad. */
2337 EH_LANDING_PAD_NR (old_lp
->post_landing_pad
) = 0;
2341 new_lp
= gen_eh_landing_pad (old_lp
->region
);
2342 new_lp
->post_landing_pad
= new_label
;
2343 EH_LANDING_PAD_NR (new_label
) = new_lp
->index
;
2346 /* Maybe move the throwing statement to the new region. */
2347 if (old_lp
!= new_lp
)
2349 remove_stmt_from_eh_lp (throw_stmt
);
2350 add_stmt_to_eh_lp (throw_stmt
, new_lp
->index
);
2354 /* Redirect EH edge E to NEW_BB. */
2357 redirect_eh_edge (edge edge_in
, basic_block new_bb
)
2359 redirect_eh_edge_1 (edge_in
, new_bb
, false);
2360 return ssa_redirect_edge (edge_in
, new_bb
);
2363 /* This is a subroutine of gimple_redirect_edge_and_branch. Update the
2364 labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
2365 The actual edge update will happen in the caller. */
2368 redirect_eh_dispatch_edge (gimple stmt
, edge e
, basic_block new_bb
)
2370 tree new_lab
= gimple_block_label (new_bb
);
2371 bool any_changed
= false;
2376 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2380 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2382 old_bb
= label_to_block (c
->label
);
2383 if (old_bb
== e
->dest
)
2391 case ERT_ALLOWED_EXCEPTIONS
:
2392 old_bb
= label_to_block (r
->u
.allowed
.label
);
2393 gcc_assert (old_bb
== e
->dest
);
2394 r
->u
.allowed
.label
= new_lab
;
2402 gcc_assert (any_changed
);
2405 /* Helper function for operation_could_trap_p and stmt_could_throw_p. */
2408 operation_could_trap_helper_p (enum tree_code op
,
2419 case TRUNC_DIV_EXPR
:
2421 case FLOOR_DIV_EXPR
:
2422 case ROUND_DIV_EXPR
:
2423 case EXACT_DIV_EXPR
:
2425 case FLOOR_MOD_EXPR
:
2426 case ROUND_MOD_EXPR
:
2427 case TRUNC_MOD_EXPR
:
2429 if (honor_snans
|| honor_trapv
)
2432 return flag_trapping_math
;
2433 if (!TREE_CONSTANT (divisor
) || integer_zerop (divisor
))
2442 /* Some floating point comparisons may trap. */
2447 case UNORDERED_EXPR
:
2457 case FIX_TRUNC_EXPR
:
2458 /* Conversion of floating point might trap. */
2464 /* These operations don't trap with floating point. */
2472 /* Any floating arithmetic may trap. */
2473 if (fp_operation
&& flag_trapping_math
)
2481 /* Constructing an object cannot trap. */
2485 /* Any floating arithmetic may trap. */
2486 if (fp_operation
&& flag_trapping_math
)
2494 /* Return true if operation OP may trap. FP_OPERATION is true if OP is applied
2495 on floating-point values. HONOR_TRAPV is true if OP is applied on integer
2496 type operands that may trap. If OP is a division operator, DIVISOR contains
2497 the value of the divisor. */
2500 operation_could_trap_p (enum tree_code op
, bool fp_operation
, bool honor_trapv
,
2503 bool honor_nans
= (fp_operation
&& flag_trapping_math
2504 && !flag_finite_math_only
);
2505 bool honor_snans
= fp_operation
&& flag_signaling_nans
!= 0;
2508 if (TREE_CODE_CLASS (op
) != tcc_comparison
2509 && TREE_CODE_CLASS (op
) != tcc_unary
2510 && TREE_CODE_CLASS (op
) != tcc_binary
)
2513 return operation_could_trap_helper_p (op
, fp_operation
, honor_trapv
,
2514 honor_nans
, honor_snans
, divisor
,
2519 /* Returns true if it is possible to prove that the index of
2520 an array access REF (an ARRAY_REF expression) falls into the
2524 in_array_bounds_p (tree ref
)
2526 tree idx
= TREE_OPERAND (ref
, 1);
2529 if (TREE_CODE (idx
) != INTEGER_CST
)
2532 min
= array_ref_low_bound (ref
);
2533 max
= array_ref_up_bound (ref
);
2536 || TREE_CODE (min
) != INTEGER_CST
2537 || TREE_CODE (max
) != INTEGER_CST
)
2540 if (tree_int_cst_lt (idx
, min
)
2541 || tree_int_cst_lt (max
, idx
))
2547 /* Returns true if it is possible to prove that the range of
2548 an array access REF (an ARRAY_RANGE_REF expression) falls
2549 into the array bounds. */
2552 range_in_array_bounds_p (tree ref
)
2554 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (ref
));
2555 tree range_min
, range_max
, min
, max
;
2557 range_min
= TYPE_MIN_VALUE (domain_type
);
2558 range_max
= TYPE_MAX_VALUE (domain_type
);
2561 || TREE_CODE (range_min
) != INTEGER_CST
2562 || TREE_CODE (range_max
) != INTEGER_CST
)
2565 min
= array_ref_low_bound (ref
);
2566 max
= array_ref_up_bound (ref
);
2569 || TREE_CODE (min
) != INTEGER_CST
2570 || TREE_CODE (max
) != INTEGER_CST
)
2573 if (tree_int_cst_lt (range_min
, min
)
2574 || tree_int_cst_lt (max
, range_max
))
2580 /* Return true if EXPR can trap, as in dereferencing an invalid pointer
2581 location or floating point arithmetic. C.f. the rtl version, may_trap_p.
2582 This routine expects only GIMPLE lhs or rhs input. */
2585 tree_could_trap_p (tree expr
)
2587 enum tree_code code
;
2588 bool fp_operation
= false;
2589 bool honor_trapv
= false;
2590 tree t
, base
, div
= NULL_TREE
;
2595 code
= TREE_CODE (expr
);
2596 t
= TREE_TYPE (expr
);
2600 if (COMPARISON_CLASS_P (expr
))
2601 fp_operation
= FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 0)));
2603 fp_operation
= FLOAT_TYPE_P (t
);
2604 honor_trapv
= INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
);
2607 if (TREE_CODE_CLASS (code
) == tcc_binary
)
2608 div
= TREE_OPERAND (expr
, 1);
2609 if (operation_could_trap_p (code
, fp_operation
, honor_trapv
, div
))
2619 case VIEW_CONVERT_EXPR
:
2620 case WITH_SIZE_EXPR
:
2621 expr
= TREE_OPERAND (expr
, 0);
2622 code
= TREE_CODE (expr
);
2625 case ARRAY_RANGE_REF
:
2626 base
= TREE_OPERAND (expr
, 0);
2627 if (tree_could_trap_p (base
))
2629 if (TREE_THIS_NOTRAP (expr
))
2631 return !range_in_array_bounds_p (expr
);
2634 base
= TREE_OPERAND (expr
, 0);
2635 if (tree_could_trap_p (base
))
2637 if (TREE_THIS_NOTRAP (expr
))
2639 return !in_array_bounds_p (expr
);
2641 case TARGET_MEM_REF
:
2643 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
2644 && tree_could_trap_p (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
2646 if (TREE_THIS_NOTRAP (expr
))
2648 /* We cannot prove that the access is in-bounds when we have
2649 variable-index TARGET_MEM_REFs. */
2650 if (code
== TARGET_MEM_REF
2651 && (TMR_INDEX (expr
) || TMR_INDEX2 (expr
)))
2653 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
)
2655 tree base
= TREE_OPERAND (TREE_OPERAND (expr
, 0), 0);
2656 offset_int off
= mem_ref_offset (expr
);
2657 if (wi::neg_p (off
, SIGNED
))
2659 if (TREE_CODE (base
) == STRING_CST
)
2660 return wi::leu_p (TREE_STRING_LENGTH (base
), off
);
2661 else if (DECL_SIZE_UNIT (base
) == NULL_TREE
2662 || TREE_CODE (DECL_SIZE_UNIT (base
)) != INTEGER_CST
2663 || wi::leu_p (wi::to_offset (DECL_SIZE_UNIT (base
)), off
))
2665 /* Now we are sure the first byte of the access is inside
2672 return !TREE_THIS_NOTRAP (expr
);
2675 return TREE_THIS_VOLATILE (expr
);
2678 t
= get_callee_fndecl (expr
);
2679 /* Assume that calls to weak functions may trap. */
2680 if (!t
|| !DECL_P (t
))
2683 return tree_could_trap_p (t
);
2687 /* Assume that accesses to weak functions may trap, unless we know
2688 they are certainly defined in current TU or in some other
2690 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
))
2692 struct cgraph_node
*node
;
2693 if (!DECL_EXTERNAL (expr
))
2695 node
= cgraph_function_node (cgraph_get_node (expr
), NULL
);
2696 if (node
&& node
->in_other_partition
)
2703 /* Assume that accesses to weak vars may trap, unless we know
2704 they are certainly defined in current TU or in some other
2706 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
))
2709 if (!DECL_EXTERNAL (expr
))
2711 node
= varpool_variable_node (varpool_get_node (expr
), NULL
);
2712 if (node
&& node
->in_other_partition
)
2724 /* Helper for stmt_could_throw_p. Return true if STMT (assumed to be a
2725 an assignment or a conditional) may throw. */
2728 stmt_could_throw_1_p (gimple stmt
)
2730 enum tree_code code
= gimple_expr_code (stmt
);
2731 bool honor_nans
= false;
2732 bool honor_snans
= false;
2733 bool fp_operation
= false;
2734 bool honor_trapv
= false;
2739 if (TREE_CODE_CLASS (code
) == tcc_comparison
2740 || TREE_CODE_CLASS (code
) == tcc_unary
2741 || TREE_CODE_CLASS (code
) == tcc_binary
)
2743 if (is_gimple_assign (stmt
)
2744 && TREE_CODE_CLASS (code
) == tcc_comparison
)
2745 t
= TREE_TYPE (gimple_assign_rhs1 (stmt
));
2746 else if (gimple_code (stmt
) == GIMPLE_COND
)
2747 t
= TREE_TYPE (gimple_cond_lhs (stmt
));
2749 t
= gimple_expr_type (stmt
);
2750 fp_operation
= FLOAT_TYPE_P (t
);
2753 honor_nans
= flag_trapping_math
&& !flag_finite_math_only
;
2754 honor_snans
= flag_signaling_nans
!= 0;
2756 else if (INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
))
2760 /* Check if the main expression may trap. */
2761 t
= is_gimple_assign (stmt
) ? gimple_assign_rhs2 (stmt
) : NULL
;
2762 ret
= operation_could_trap_helper_p (code
, fp_operation
, honor_trapv
,
2763 honor_nans
, honor_snans
, t
,
2768 /* If the expression does not trap, see if any of the individual operands may
2770 for (i
= 0; i
< gimple_num_ops (stmt
); i
++)
2771 if (tree_could_trap_p (gimple_op (stmt
, i
)))
2778 /* Return true if statement STMT could throw an exception. */
2781 stmt_could_throw_p (gimple stmt
)
2783 if (!flag_exceptions
)
2786 /* The only statements that can throw an exception are assignments,
2787 conditionals, calls, resx, and asms. */
2788 switch (gimple_code (stmt
))
2794 return !gimple_call_nothrow_p (stmt
);
2798 if (!cfun
->can_throw_non_call_exceptions
)
2800 return stmt_could_throw_1_p (stmt
);
2803 if (!cfun
->can_throw_non_call_exceptions
)
2805 return gimple_asm_volatile_p (stmt
);
2813 /* Return true if expression T could throw an exception. */
2816 tree_could_throw_p (tree t
)
2818 if (!flag_exceptions
)
2820 if (TREE_CODE (t
) == MODIFY_EXPR
)
2822 if (cfun
->can_throw_non_call_exceptions
2823 && tree_could_trap_p (TREE_OPERAND (t
, 0)))
2825 t
= TREE_OPERAND (t
, 1);
2828 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
2829 t
= TREE_OPERAND (t
, 0);
2830 if (TREE_CODE (t
) == CALL_EXPR
)
2831 return (call_expr_flags (t
) & ECF_NOTHROW
) == 0;
2832 if (cfun
->can_throw_non_call_exceptions
)
2833 return tree_could_trap_p (t
);
2837 /* Return true if STMT can throw an exception that is not caught within
2838 the current function (CFUN). */
2841 stmt_can_throw_external (gimple stmt
)
2845 if (!stmt_could_throw_p (stmt
))
2848 lp_nr
= lookup_stmt_eh_lp (stmt
);
2852 /* Return true if STMT can throw an exception that is caught within
2853 the current function (CFUN). */
2856 stmt_can_throw_internal (gimple stmt
)
2860 if (!stmt_could_throw_p (stmt
))
2863 lp_nr
= lookup_stmt_eh_lp (stmt
);
2867 /* Given a statement STMT in IFUN, if STMT can no longer throw, then
2868 remove any entry it might have from the EH table. Return true if
2869 any change was made. */
2872 maybe_clean_eh_stmt_fn (struct function
*ifun
, gimple stmt
)
2874 if (stmt_could_throw_p (stmt
))
2876 return remove_stmt_from_eh_lp_fn (ifun
, stmt
);
2879 /* Likewise, but always use the current function. */
2882 maybe_clean_eh_stmt (gimple stmt
)
2884 return maybe_clean_eh_stmt_fn (cfun
, stmt
);
2887 /* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
2888 OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
2889 in the table if it should be in there. Return TRUE if a replacement was
2890 done that my require an EH edge purge. */
2893 maybe_clean_or_replace_eh_stmt (gimple old_stmt
, gimple new_stmt
)
2895 int lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2899 bool new_stmt_could_throw
= stmt_could_throw_p (new_stmt
);
2901 if (new_stmt
== old_stmt
&& new_stmt_could_throw
)
2904 remove_stmt_from_eh_lp (old_stmt
);
2905 if (new_stmt_could_throw
)
2907 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
2917 /* Given a statement OLD_STMT in OLD_FUN and a duplicate statement NEW_STMT
2918 in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT. The MAP
2919 operand is the return value of duplicate_eh_regions. */
2922 maybe_duplicate_eh_stmt_fn (struct function
*new_fun
, gimple new_stmt
,
2923 struct function
*old_fun
, gimple old_stmt
,
2924 struct pointer_map_t
*map
, int default_lp_nr
)
2926 int old_lp_nr
, new_lp_nr
;
2929 if (!stmt_could_throw_p (new_stmt
))
2932 old_lp_nr
= lookup_stmt_eh_lp_fn (old_fun
, old_stmt
);
2935 if (default_lp_nr
== 0)
2937 new_lp_nr
= default_lp_nr
;
2939 else if (old_lp_nr
> 0)
2941 eh_landing_pad old_lp
, new_lp
;
2943 old_lp
= (*old_fun
->eh
->lp_array
)[old_lp_nr
];
2944 slot
= pointer_map_contains (map
, old_lp
);
2945 new_lp
= (eh_landing_pad
) *slot
;
2946 new_lp_nr
= new_lp
->index
;
2950 eh_region old_r
, new_r
;
2952 old_r
= (*old_fun
->eh
->region_array
)[-old_lp_nr
];
2953 slot
= pointer_map_contains (map
, old_r
);
2954 new_r
= (eh_region
) *slot
;
2955 new_lp_nr
= -new_r
->index
;
2958 add_stmt_to_eh_lp_fn (new_fun
, new_stmt
, new_lp_nr
);
2962 /* Similar, but both OLD_STMT and NEW_STMT are within the current function,
2963 and thus no remapping is required. */
2966 maybe_duplicate_eh_stmt (gimple new_stmt
, gimple old_stmt
)
2970 if (!stmt_could_throw_p (new_stmt
))
2973 lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2977 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
2981 /* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of
2982 GIMPLE_TRY) that are similar enough to be considered the same. Currently
2983 this only handles handlers consisting of a single call, as that's the
2984 important case for C++: a destructor call for a particular object showing
2985 up in multiple handlers. */
2988 same_handler_p (gimple_seq oneh
, gimple_seq twoh
)
2990 gimple_stmt_iterator gsi
;
2994 gsi
= gsi_start (oneh
);
2995 if (!gsi_one_before_end_p (gsi
))
2997 ones
= gsi_stmt (gsi
);
2999 gsi
= gsi_start (twoh
);
3000 if (!gsi_one_before_end_p (gsi
))
3002 twos
= gsi_stmt (gsi
);
3004 if (!is_gimple_call (ones
)
3005 || !is_gimple_call (twos
)
3006 || gimple_call_lhs (ones
)
3007 || gimple_call_lhs (twos
)
3008 || gimple_call_chain (ones
)
3009 || gimple_call_chain (twos
)
3010 || !gimple_call_same_target_p (ones
, twos
)
3011 || gimple_call_num_args (ones
) != gimple_call_num_args (twos
))
3014 for (ai
= 0; ai
< gimple_call_num_args (ones
); ++ai
)
3015 if (!operand_equal_p (gimple_call_arg (ones
, ai
),
3016 gimple_call_arg (twos
, ai
), 0))
3023 try { A() } finally { try { ~B() } catch { ~A() } }
3024 try { ... } finally { ~A() }
3026 try { A() } catch { ~B() }
3027 try { ~B() ... } finally { ~A() }
3029 This occurs frequently in C++, where A is a local variable and B is a
3030 temporary used in the initializer for A. */
3033 optimize_double_finally (gimple one
, gimple two
)
3036 gimple_stmt_iterator gsi
;
3039 cleanup
= gimple_try_cleanup (one
);
3040 gsi
= gsi_start (cleanup
);
3041 if (!gsi_one_before_end_p (gsi
))
3044 oneh
= gsi_stmt (gsi
);
3045 if (gimple_code (oneh
) != GIMPLE_TRY
3046 || gimple_try_kind (oneh
) != GIMPLE_TRY_CATCH
)
3049 if (same_handler_p (gimple_try_cleanup (oneh
), gimple_try_cleanup (two
)))
3051 gimple_seq seq
= gimple_try_eval (oneh
);
3053 gimple_try_set_cleanup (one
, seq
);
3054 gimple_try_set_kind (one
, GIMPLE_TRY_CATCH
);
3055 seq
= copy_gimple_seq_and_replace_locals (seq
);
3056 gimple_seq_add_seq (&seq
, gimple_try_eval (two
));
3057 gimple_try_set_eval (two
, seq
);
3061 /* Perform EH refactoring optimizations that are simpler to do when code
3062 flow has been lowered but EH structures haven't. */
3065 refactor_eh_r (gimple_seq seq
)
3067 gimple_stmt_iterator gsi
;
3072 gsi
= gsi_start (seq
);
3076 if (gsi_end_p (gsi
))
3079 two
= gsi_stmt (gsi
);
3082 && gimple_code (one
) == GIMPLE_TRY
3083 && gimple_code (two
) == GIMPLE_TRY
3084 && gimple_try_kind (one
) == GIMPLE_TRY_FINALLY
3085 && gimple_try_kind (two
) == GIMPLE_TRY_FINALLY
)
3086 optimize_double_finally (one
, two
);
3088 switch (gimple_code (one
))
3091 refactor_eh_r (gimple_try_eval (one
));
3092 refactor_eh_r (gimple_try_cleanup (one
));
3095 refactor_eh_r (gimple_catch_handler (one
));
3097 case GIMPLE_EH_FILTER
:
3098 refactor_eh_r (gimple_eh_filter_failure (one
));
3100 case GIMPLE_EH_ELSE
:
3101 refactor_eh_r (gimple_eh_else_n_body (one
));
3102 refactor_eh_r (gimple_eh_else_e_body (one
));
3116 const pass_data pass_data_refactor_eh
=
3118 GIMPLE_PASS
, /* type */
3120 OPTGROUP_NONE
, /* optinfo_flags */
3121 true, /* has_execute */
3122 TV_TREE_EH
, /* tv_id */
3123 PROP_gimple_lcf
, /* properties_required */
3124 0, /* properties_provided */
3125 0, /* properties_destroyed */
3126 0, /* todo_flags_start */
3127 0, /* todo_flags_finish */
3130 class pass_refactor_eh
: public gimple_opt_pass
3133 pass_refactor_eh (gcc::context
*ctxt
)
3134 : gimple_opt_pass (pass_data_refactor_eh
, ctxt
)
3137 /* opt_pass methods: */
3138 virtual bool gate (function
*) { return flag_exceptions
!= 0; }
3139 virtual unsigned int execute (function
*)
3141 refactor_eh_r (gimple_body (current_function_decl
));
3145 }; // class pass_refactor_eh
3150 make_pass_refactor_eh (gcc::context
*ctxt
)
3152 return new pass_refactor_eh (ctxt
);
3155 /* At the end of gimple optimization, we can lower RESX. */
3158 lower_resx (basic_block bb
, gimple stmt
, struct pointer_map_t
*mnt_map
)
3161 eh_region src_r
, dst_r
;
3162 gimple_stmt_iterator gsi
;
3167 lp_nr
= lookup_stmt_eh_lp (stmt
);
3169 dst_r
= get_eh_region_from_lp_number (lp_nr
);
3173 src_r
= get_eh_region_from_number (gimple_resx_region (stmt
));
3174 gsi
= gsi_last_bb (bb
);
3178 /* We can wind up with no source region when pass_cleanup_eh shows
3179 that there are no entries into an eh region and deletes it, but
3180 then the block that contains the resx isn't removed. This can
3181 happen without optimization when the switch statement created by
3182 lower_try_finally_switch isn't simplified to remove the eh case.
3184 Resolve this by expanding the resx node to an abort. */
3186 fn
= builtin_decl_implicit (BUILT_IN_TRAP
);
3187 x
= gimple_build_call (fn
, 0);
3188 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3190 while (EDGE_COUNT (bb
->succs
) > 0)
3191 remove_edge (EDGE_SUCC (bb
, 0));
3195 /* When we have a destination region, we resolve this by copying
3196 the excptr and filter values into place, and changing the edge
3197 to immediately after the landing pad. */
3206 /* We are resuming into a MUST_NOT_CALL region. Expand a call to
3207 the failure decl into a new block, if needed. */
3208 gcc_assert (dst_r
->type
== ERT_MUST_NOT_THROW
);
3210 slot
= pointer_map_contains (mnt_map
, dst_r
);
3213 gimple_stmt_iterator gsi2
;
3215 new_bb
= create_empty_bb (bb
);
3216 add_bb_to_loop (new_bb
, bb
->loop_father
);
3217 lab
= gimple_block_label (new_bb
);
3218 gsi2
= gsi_start_bb (new_bb
);
3220 fn
= dst_r
->u
.must_not_throw
.failure_decl
;
3221 x
= gimple_build_call (fn
, 0);
3222 gimple_set_location (x
, dst_r
->u
.must_not_throw
.failure_loc
);
3223 gsi_insert_after (&gsi2
, x
, GSI_CONTINUE_LINKING
);
3225 slot
= pointer_map_insert (mnt_map
, dst_r
);
3231 new_bb
= label_to_block (lab
);
3234 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3235 e
= make_edge (bb
, new_bb
, EDGE_FALLTHRU
);
3236 e
->count
= bb
->count
;
3237 e
->probability
= REG_BR_PROB_BASE
;
3242 tree dst_nr
= build_int_cst (integer_type_node
, dst_r
->index
);
3244 fn
= builtin_decl_implicit (BUILT_IN_EH_COPY_VALUES
);
3245 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3246 x
= gimple_build_call (fn
, 2, dst_nr
, src_nr
);
3247 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3249 /* Update the flags for the outgoing edge. */
3250 e
= single_succ_edge (bb
);
3251 gcc_assert (e
->flags
& EDGE_EH
);
3252 e
->flags
= (e
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
3254 /* If there are no more EH users of the landing pad, delete it. */
3255 FOR_EACH_EDGE (e
, ei
, e
->dest
->preds
)
3256 if (e
->flags
& EDGE_EH
)
3260 eh_landing_pad lp
= get_eh_landing_pad_from_number (lp_nr
);
3261 remove_eh_landing_pad (lp
);
3271 /* When we don't have a destination region, this exception escapes
3272 up the call chain. We resolve this by generating a call to the
3273 _Unwind_Resume library function. */
3275 /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup
3276 with no arguments for C++ and Java. Check for that. */
3277 if (src_r
->use_cxa_end_cleanup
)
3279 fn
= builtin_decl_implicit (BUILT_IN_CXA_END_CLEANUP
);
3280 x
= gimple_build_call (fn
, 0);
3281 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3285 fn
= builtin_decl_implicit (BUILT_IN_EH_POINTER
);
3286 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3287 x
= gimple_build_call (fn
, 1, src_nr
);
3288 var
= create_tmp_var (ptr_type_node
, NULL
);
3289 var
= make_ssa_name (var
, x
);
3290 gimple_call_set_lhs (x
, var
);
3291 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3293 fn
= builtin_decl_implicit (BUILT_IN_UNWIND_RESUME
);
3294 x
= gimple_build_call (fn
, 1, var
);
3295 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3298 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3301 gsi_remove (&gsi
, true);
3308 const pass_data pass_data_lower_resx
=
3310 GIMPLE_PASS
, /* type */
3312 OPTGROUP_NONE
, /* optinfo_flags */
3313 true, /* has_execute */
3314 TV_TREE_EH
, /* tv_id */
3315 PROP_gimple_lcf
, /* properties_required */
3316 0, /* properties_provided */
3317 0, /* properties_destroyed */
3318 0, /* todo_flags_start */
3319 0, /* todo_flags_finish */
3322 class pass_lower_resx
: public gimple_opt_pass
3325 pass_lower_resx (gcc::context
*ctxt
)
3326 : gimple_opt_pass (pass_data_lower_resx
, ctxt
)
3329 /* opt_pass methods: */
3330 virtual bool gate (function
*) { return flag_exceptions
!= 0; }
3331 virtual unsigned int execute (function
*);
3333 }; // class pass_lower_resx
3336 pass_lower_resx::execute (function
*fun
)
3339 struct pointer_map_t
*mnt_map
;
3340 bool dominance_invalidated
= false;
3341 bool any_rewritten
= false;
3343 mnt_map
= pointer_map_create ();
3345 FOR_EACH_BB_FN (bb
, fun
)
3347 gimple last
= last_stmt (bb
);
3348 if (last
&& is_gimple_resx (last
))
3350 dominance_invalidated
|= lower_resx (bb
, last
, mnt_map
);
3351 any_rewritten
= true;
3355 pointer_map_destroy (mnt_map
);
3357 if (dominance_invalidated
)
3359 free_dominance_info (CDI_DOMINATORS
);
3360 free_dominance_info (CDI_POST_DOMINATORS
);
3363 return any_rewritten
? TODO_update_ssa_only_virtuals
: 0;
3369 make_pass_lower_resx (gcc::context
*ctxt
)
3371 return new pass_lower_resx (ctxt
);
3374 /* Try to optimize var = {v} {CLOBBER} stmts followed just by
3378 optimize_clobbers (basic_block bb
)
3380 gimple_stmt_iterator gsi
= gsi_last_bb (bb
);
3381 bool any_clobbers
= false;
3382 bool seen_stack_restore
= false;
3386 /* Only optimize anything if the bb contains at least one clobber,
3387 ends with resx (checked by caller), optionally contains some
3388 debug stmts or labels, or at most one __builtin_stack_restore
3389 call, and has an incoming EH edge. */
3390 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3392 gimple stmt
= gsi_stmt (gsi
);
3393 if (is_gimple_debug (stmt
))
3395 if (gimple_clobber_p (stmt
))
3397 any_clobbers
= true;
3400 if (!seen_stack_restore
3401 && gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
3403 seen_stack_restore
= true;
3406 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3412 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3413 if (e
->flags
& EDGE_EH
)
3417 gsi
= gsi_last_bb (bb
);
3418 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3420 gimple stmt
= gsi_stmt (gsi
);
3421 if (!gimple_clobber_p (stmt
))
3423 unlink_stmt_vdef (stmt
);
3424 gsi_remove (&gsi
, true);
3425 release_defs (stmt
);
3429 /* Try to sink var = {v} {CLOBBER} stmts followed just by
3430 internal throw to successor BB. */
3433 sink_clobbers (basic_block bb
)
3437 gimple_stmt_iterator gsi
, dgsi
;
3439 bool any_clobbers
= false;
3442 /* Only optimize if BB has a single EH successor and
3443 all predecessor edges are EH too. */
3444 if (!single_succ_p (bb
)
3445 || (single_succ_edge (bb
)->flags
& EDGE_EH
) == 0)
3448 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3450 if ((e
->flags
& EDGE_EH
) == 0)
3454 /* And BB contains only CLOBBER stmts before the final
3456 gsi
= gsi_last_bb (bb
);
3457 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3459 gimple stmt
= gsi_stmt (gsi
);
3460 if (is_gimple_debug (stmt
))
3462 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3464 if (!gimple_clobber_p (stmt
))
3466 any_clobbers
= true;
3471 edge succe
= single_succ_edge (bb
);
3472 succbb
= succe
->dest
;
3474 /* See if there is a virtual PHI node to take an updated virtual
3477 tree vuse
= NULL_TREE
;
3478 for (gsi
= gsi_start_phis (succbb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3480 tree res
= gimple_phi_result (gsi_stmt (gsi
));
3481 if (virtual_operand_p (res
))
3483 vphi
= gsi_stmt (gsi
);
3489 dgsi
= gsi_after_labels (succbb
);
3490 gsi
= gsi_last_bb (bb
);
3491 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3493 gimple stmt
= gsi_stmt (gsi
);
3495 if (is_gimple_debug (stmt
))
3497 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3499 lhs
= gimple_assign_lhs (stmt
);
3500 /* Unfortunately we don't have dominance info updated at this
3501 point, so checking if
3502 dominated_by_p (CDI_DOMINATORS, succbb,
3503 gimple_bb (SSA_NAME_DEF_STMT (TREE_OPERAND (lhs, 0)))
3504 would be too costly. Thus, avoid sinking any clobbers that
3505 refer to non-(D) SSA_NAMEs. */
3506 if (TREE_CODE (lhs
) == MEM_REF
3507 && TREE_CODE (TREE_OPERAND (lhs
, 0)) == SSA_NAME
3508 && !SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs
, 0)))
3510 unlink_stmt_vdef (stmt
);
3511 gsi_remove (&gsi
, true);
3512 release_defs (stmt
);
3516 /* As we do not change stmt order when sinking across a
3517 forwarder edge we can keep virtual operands in place. */
3518 gsi_remove (&gsi
, false);
3519 gsi_insert_before (&dgsi
, stmt
, GSI_NEW_STMT
);
3521 /* But adjust virtual operands if we sunk across a PHI node. */
3525 imm_use_iterator iter
;
3526 use_operand_p use_p
;
3527 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, vuse
)
3528 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
3529 SET_USE (use_p
, gimple_vdef (stmt
));
3530 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
))
3532 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vdef (stmt
)) = 1;
3533 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
) = 0;
3535 /* Adjust the incoming virtual operand. */
3536 SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (vphi
, succe
), gimple_vuse (stmt
));
3537 SET_USE (gimple_vuse_op (stmt
), vuse
);
3539 /* If there isn't a single predecessor but no virtual PHI node
3540 arrange for virtual operands to be renamed. */
3541 else if (gimple_vuse_op (stmt
) != NULL_USE_OPERAND_P
3542 && !single_pred_p (succbb
))
3544 /* In this case there will be no use of the VDEF of this stmt.
3545 ??? Unless this is a secondary opportunity and we have not
3546 removed unreachable blocks yet, so we cannot assert this.
3547 Which also means we will end up renaming too many times. */
3548 SET_USE (gimple_vuse_op (stmt
), gimple_vop (cfun
));
3549 mark_virtual_operands_for_renaming (cfun
);
3550 todo
|= TODO_update_ssa_only_virtuals
;
3557 /* At the end of inlining, we can lower EH_DISPATCH. Return true when
3558 we have found some duplicate labels and removed some edges. */
3561 lower_eh_dispatch (basic_block src
, gimple stmt
)
3563 gimple_stmt_iterator gsi
;
3568 bool redirected
= false;
3570 region_nr
= gimple_eh_dispatch_region (stmt
);
3571 r
= get_eh_region_from_number (region_nr
);
3573 gsi
= gsi_last_bb (src
);
3579 auto_vec
<tree
> labels
;
3580 tree default_label
= NULL
;
3584 struct pointer_set_t
*seen_values
= pointer_set_create ();
3586 /* Collect the labels for a switch. Zero the post_landing_pad
3587 field becase we'll no longer have anything keeping these labels
3588 in existence and the optimizer will be free to merge these
3590 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
3592 tree tp_node
, flt_node
, lab
= c
->label
;
3593 bool have_label
= false;
3596 tp_node
= c
->type_list
;
3597 flt_node
= c
->filter_list
;
3599 if (tp_node
== NULL
)
3601 default_label
= lab
;
3606 /* Filter out duplicate labels that arise when this handler
3607 is shadowed by an earlier one. When no labels are
3608 attached to the handler anymore, we remove
3609 the corresponding edge and then we delete unreachable
3610 blocks at the end of this pass. */
3611 if (! pointer_set_contains (seen_values
, TREE_VALUE (flt_node
)))
3613 tree t
= build_case_label (TREE_VALUE (flt_node
),
3615 labels
.safe_push (t
);
3616 pointer_set_insert (seen_values
, TREE_VALUE (flt_node
));
3620 tp_node
= TREE_CHAIN (tp_node
);
3621 flt_node
= TREE_CHAIN (flt_node
);
3626 remove_edge (find_edge (src
, label_to_block (lab
)));
3631 /* Clean up the edge flags. */
3632 FOR_EACH_EDGE (e
, ei
, src
->succs
)
3634 if (e
->flags
& EDGE_FALLTHRU
)
3636 /* If there was no catch-all, use the fallthru edge. */
3637 if (default_label
== NULL
)
3638 default_label
= gimple_block_label (e
->dest
);
3639 e
->flags
&= ~EDGE_FALLTHRU
;
3642 gcc_assert (default_label
!= NULL
);
3644 /* Don't generate a switch if there's only a default case.
3645 This is common in the form of try { A; } catch (...) { B; }. */
3646 if (!labels
.exists ())
3648 e
= single_succ_edge (src
);
3649 e
->flags
|= EDGE_FALLTHRU
;
3653 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3654 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3656 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)), NULL
);
3657 filter
= make_ssa_name (filter
, x
);
3658 gimple_call_set_lhs (x
, filter
);
3659 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3661 /* Turn the default label into a default case. */
3662 default_label
= build_case_label (NULL
, NULL
, default_label
);
3663 sort_case_labels (labels
);
3665 x
= gimple_build_switch (filter
, default_label
, labels
);
3666 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3668 pointer_set_destroy (seen_values
);
3672 case ERT_ALLOWED_EXCEPTIONS
:
3674 edge b_e
= BRANCH_EDGE (src
);
3675 edge f_e
= FALLTHRU_EDGE (src
);
3677 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3678 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3680 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)), NULL
);
3681 filter
= make_ssa_name (filter
, x
);
3682 gimple_call_set_lhs (x
, filter
);
3683 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3685 r
->u
.allowed
.label
= NULL
;
3686 x
= gimple_build_cond (EQ_EXPR
, filter
,
3687 build_int_cst (TREE_TYPE (filter
),
3688 r
->u
.allowed
.filter
),
3689 NULL_TREE
, NULL_TREE
);
3690 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3692 b_e
->flags
= b_e
->flags
| EDGE_TRUE_VALUE
;
3693 f_e
->flags
= (f_e
->flags
& ~EDGE_FALLTHRU
) | EDGE_FALSE_VALUE
;
3701 /* Replace the EH_DISPATCH with the SWITCH or COND generated above. */
3702 gsi_remove (&gsi
, true);
3708 const pass_data pass_data_lower_eh_dispatch
=
3710 GIMPLE_PASS
, /* type */
3711 "ehdisp", /* name */
3712 OPTGROUP_NONE
, /* optinfo_flags */
3713 true, /* has_execute */
3714 TV_TREE_EH
, /* tv_id */
3715 PROP_gimple_lcf
, /* properties_required */
3716 0, /* properties_provided */
3717 0, /* properties_destroyed */
3718 0, /* todo_flags_start */
3719 0, /* todo_flags_finish */
3722 class pass_lower_eh_dispatch
: public gimple_opt_pass
3725 pass_lower_eh_dispatch (gcc::context
*ctxt
)
3726 : gimple_opt_pass (pass_data_lower_eh_dispatch
, ctxt
)
3729 /* opt_pass methods: */
3730 virtual bool gate (function
*fun
) { return fun
->eh
->region_tree
!= NULL
; }
3731 virtual unsigned int execute (function
*);
3733 }; // class pass_lower_eh_dispatch
3736 pass_lower_eh_dispatch::execute (function
*fun
)
3740 bool redirected
= false;
3742 assign_filter_values ();
3744 FOR_EACH_BB_FN (bb
, fun
)
3746 gimple last
= last_stmt (bb
);
3749 if (gimple_code (last
) == GIMPLE_EH_DISPATCH
)
3751 redirected
|= lower_eh_dispatch (bb
, last
);
3752 flags
|= TODO_update_ssa_only_virtuals
;
3754 else if (gimple_code (last
) == GIMPLE_RESX
)
3756 if (stmt_can_throw_external (last
))
3757 optimize_clobbers (bb
);
3759 flags
|= sink_clobbers (bb
);
3764 delete_unreachable_blocks ();
3771 make_pass_lower_eh_dispatch (gcc::context
*ctxt
)
3773 return new pass_lower_eh_dispatch (ctxt
);
3776 /* Walk statements, see what regions and, optionally, landing pads
3777 are really referenced.
3779 Returns in R_REACHABLEP an sbitmap with bits set for reachable regions,
3780 and in LP_REACHABLE an sbitmap with bits set for reachable landing pads.
3782 Passing NULL for LP_REACHABLE is valid, in this case only reachable
3785 The caller is responsible for freeing the returned sbitmaps. */
3788 mark_reachable_handlers (sbitmap
*r_reachablep
, sbitmap
*lp_reachablep
)
3790 sbitmap r_reachable
, lp_reachable
;
3792 bool mark_landing_pads
= (lp_reachablep
!= NULL
);
3793 gcc_checking_assert (r_reachablep
!= NULL
);
3795 r_reachable
= sbitmap_alloc (cfun
->eh
->region_array
->length ());
3796 bitmap_clear (r_reachable
);
3797 *r_reachablep
= r_reachable
;
3799 if (mark_landing_pads
)
3801 lp_reachable
= sbitmap_alloc (cfun
->eh
->lp_array
->length ());
3802 bitmap_clear (lp_reachable
);
3803 *lp_reachablep
= lp_reachable
;
3806 lp_reachable
= NULL
;
3808 FOR_EACH_BB_FN (bb
, cfun
)
3810 gimple_stmt_iterator gsi
;
3812 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3814 gimple stmt
= gsi_stmt (gsi
);
3816 if (mark_landing_pads
)
3818 int lp_nr
= lookup_stmt_eh_lp (stmt
);
3820 /* Negative LP numbers are MUST_NOT_THROW regions which
3821 are not considered BB enders. */
3823 bitmap_set_bit (r_reachable
, -lp_nr
);
3825 /* Positive LP numbers are real landing pads, and BB enders. */
3828 gcc_assert (gsi_one_before_end_p (gsi
));
3829 eh_region region
= get_eh_region_from_lp_number (lp_nr
);
3830 bitmap_set_bit (r_reachable
, region
->index
);
3831 bitmap_set_bit (lp_reachable
, lp_nr
);
3835 /* Avoid removing regions referenced from RESX/EH_DISPATCH. */
3836 switch (gimple_code (stmt
))
3839 bitmap_set_bit (r_reachable
, gimple_resx_region (stmt
));
3841 case GIMPLE_EH_DISPATCH
:
3842 bitmap_set_bit (r_reachable
, gimple_eh_dispatch_region (stmt
));
3851 /* Remove unreachable handlers and unreachable landing pads. */
3854 remove_unreachable_handlers (void)
3856 sbitmap r_reachable
, lp_reachable
;
3861 mark_reachable_handlers (&r_reachable
, &lp_reachable
);
3865 fprintf (dump_file
, "Before removal of unreachable regions:\n");
3866 dump_eh_tree (dump_file
, cfun
);
3867 fprintf (dump_file
, "Reachable regions: ");
3868 dump_bitmap_file (dump_file
, r_reachable
);
3869 fprintf (dump_file
, "Reachable landing pads: ");
3870 dump_bitmap_file (dump_file
, lp_reachable
);
3875 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3876 if (region
&& !bitmap_bit_p (r_reachable
, region
->index
))
3878 "Removing unreachable region %d\n",
3882 remove_unreachable_eh_regions (r_reachable
);
3884 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3885 if (lp
&& !bitmap_bit_p (lp_reachable
, lp
->index
))
3889 "Removing unreachable landing pad %d\n",
3891 remove_eh_landing_pad (lp
);
3896 fprintf (dump_file
, "\n\nAfter removal of unreachable regions:\n");
3897 dump_eh_tree (dump_file
, cfun
);
3898 fprintf (dump_file
, "\n\n");
3901 sbitmap_free (r_reachable
);
3902 sbitmap_free (lp_reachable
);
3904 #ifdef ENABLE_CHECKING
3905 verify_eh_tree (cfun
);
3909 /* Remove unreachable handlers if any landing pads have been removed after
3910 last ehcleanup pass (due to gimple_purge_dead_eh_edges). */
3913 maybe_remove_unreachable_handlers (void)
3918 if (cfun
->eh
== NULL
)
3921 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3922 if (lp
&& lp
->post_landing_pad
)
3924 if (label_to_block (lp
->post_landing_pad
) == NULL
)
3926 remove_unreachable_handlers ();
3932 /* Remove regions that do not have landing pads. This assumes
3933 that remove_unreachable_handlers has already been run, and
3934 that we've just manipulated the landing pads since then.
3936 Preserve regions with landing pads and regions that prevent
3937 exceptions from propagating further, even if these regions
3938 are not reachable. */
3941 remove_unreachable_handlers_no_lp (void)
3944 sbitmap r_reachable
;
3947 mark_reachable_handlers (&r_reachable
, /*lp_reachablep=*/NULL
);
3949 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3954 if (region
->landing_pads
!= NULL
3955 || region
->type
== ERT_MUST_NOT_THROW
)
3956 bitmap_set_bit (r_reachable
, region
->index
);
3959 && !bitmap_bit_p (r_reachable
, region
->index
))
3961 "Removing unreachable region %d\n",
3965 remove_unreachable_eh_regions (r_reachable
);
3967 sbitmap_free (r_reachable
);
3970 /* Undo critical edge splitting on an EH landing pad. Earlier, we
3971 optimisticaly split all sorts of edges, including EH edges. The
3972 optimization passes in between may not have needed them; if not,
3973 we should undo the split.
3975 Recognize this case by having one EH edge incoming to the BB and
3976 one normal edge outgoing; BB should be empty apart from the
3977 post_landing_pad label.
3979 Note that this is slightly different from the empty handler case
3980 handled by cleanup_empty_eh, in that the actual handler may yet
3981 have actual code but the landing pad has been separated from the
3982 handler. As such, cleanup_empty_eh relies on this transformation
3983 having been done first. */
3986 unsplit_eh (eh_landing_pad lp
)
3988 basic_block bb
= label_to_block (lp
->post_landing_pad
);
3989 gimple_stmt_iterator gsi
;
3992 /* Quickly check the edge counts on BB for singularity. */
3993 if (!single_pred_p (bb
) || !single_succ_p (bb
))
3995 e_in
= single_pred_edge (bb
);
3996 e_out
= single_succ_edge (bb
);
3998 /* Input edge must be EH and output edge must be normal. */
3999 if ((e_in
->flags
& EDGE_EH
) == 0 || (e_out
->flags
& EDGE_EH
) != 0)
4002 /* The block must be empty except for the labels and debug insns. */
4003 gsi
= gsi_after_labels (bb
);
4004 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4005 gsi_next_nondebug (&gsi
);
4006 if (!gsi_end_p (gsi
))
4009 /* The destination block must not already have a landing pad
4010 for a different region. */
4011 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4013 gimple stmt
= gsi_stmt (gsi
);
4017 if (gimple_code (stmt
) != GIMPLE_LABEL
)
4019 lab
= gimple_label_label (stmt
);
4020 lp_nr
= EH_LANDING_PAD_NR (lab
);
4021 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4025 /* The new destination block must not already be a destination of
4026 the source block, lest we merge fallthru and eh edges and get
4027 all sorts of confused. */
4028 if (find_edge (e_in
->src
, e_out
->dest
))
4031 /* ??? We can get degenerate phis due to cfg cleanups. I would have
4032 thought this should have been cleaned up by a phicprop pass, but
4033 that doesn't appear to handle virtuals. Propagate by hand. */
4034 if (!gimple_seq_empty_p (phi_nodes (bb
)))
4036 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); )
4038 gimple use_stmt
, phi
= gsi_stmt (gsi
);
4039 tree lhs
= gimple_phi_result (phi
);
4040 tree rhs
= gimple_phi_arg_def (phi
, 0);
4041 use_operand_p use_p
;
4042 imm_use_iterator iter
;
4044 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
4046 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
4047 SET_USE (use_p
, rhs
);
4050 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
4051 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs
) = 1;
4053 remove_phi_node (&gsi
, true);
4057 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4058 fprintf (dump_file
, "Unsplit EH landing pad %d to block %i.\n",
4059 lp
->index
, e_out
->dest
->index
);
4061 /* Redirect the edge. Since redirect_eh_edge_1 expects to be moving
4062 a successor edge, humor it. But do the real CFG change with the
4063 predecessor of E_OUT in order to preserve the ordering of arguments
4064 to the PHI nodes in E_OUT->DEST. */
4065 redirect_eh_edge_1 (e_in
, e_out
->dest
, false);
4066 redirect_edge_pred (e_out
, e_in
->src
);
4067 e_out
->flags
= e_in
->flags
;
4068 e_out
->probability
= e_in
->probability
;
4069 e_out
->count
= e_in
->count
;
4075 /* Examine each landing pad block and see if it matches unsplit_eh. */
4078 unsplit_all_eh (void)
4080 bool changed
= false;
4084 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4086 changed
|= unsplit_eh (lp
);
4091 /* A subroutine of cleanup_empty_eh. Redirect all EH edges incoming
4092 to OLD_BB to NEW_BB; return true on success, false on failure.
4094 OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any
4095 PHI variables from OLD_BB we can pick them up from OLD_BB_OUT.
4096 Virtual PHIs may be deleted and marked for renaming. */
4099 cleanup_empty_eh_merge_phis (basic_block new_bb
, basic_block old_bb
,
4100 edge old_bb_out
, bool change_region
)
4102 gimple_stmt_iterator ngsi
, ogsi
;
4105 bitmap ophi_handled
;
4107 /* The destination block must not be a regular successor for any
4108 of the preds of the landing pad. Thus, avoid turning
4118 which CFG verification would choke on. See PR45172 and PR51089. */
4119 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4120 if (find_edge (e
->src
, new_bb
))
4123 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4124 redirect_edge_var_map_clear (e
);
4126 ophi_handled
= BITMAP_ALLOC (NULL
);
4128 /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
4129 for the edges we're going to move. */
4130 for (ngsi
= gsi_start_phis (new_bb
); !gsi_end_p (ngsi
); gsi_next (&ngsi
))
4132 gimple ophi
, nphi
= gsi_stmt (ngsi
);
4135 nresult
= gimple_phi_result (nphi
);
4136 nop
= gimple_phi_arg_def (nphi
, old_bb_out
->dest_idx
);
4138 /* Find the corresponding PHI in OLD_BB so we can forward-propagate
4139 the source ssa_name. */
4141 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4143 ophi
= gsi_stmt (ogsi
);
4144 if (gimple_phi_result (ophi
) == nop
)
4149 /* If we did find the corresponding PHI, copy those inputs. */
4152 /* If NOP is used somewhere else beyond phis in new_bb, give up. */
4153 if (!has_single_use (nop
))
4155 imm_use_iterator imm_iter
;
4156 use_operand_p use_p
;
4158 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, nop
)
4160 if (!gimple_debug_bind_p (USE_STMT (use_p
))
4161 && (gimple_code (USE_STMT (use_p
)) != GIMPLE_PHI
4162 || gimple_bb (USE_STMT (use_p
)) != new_bb
))
4166 bitmap_set_bit (ophi_handled
, SSA_NAME_VERSION (nop
));
4167 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4172 if ((e
->flags
& EDGE_EH
) == 0)
4174 oop
= gimple_phi_arg_def (ophi
, e
->dest_idx
);
4175 oloc
= gimple_phi_arg_location (ophi
, e
->dest_idx
);
4176 redirect_edge_var_map_add (e
, nresult
, oop
, oloc
);
4179 /* If we didn't find the PHI, if it's a real variable or a VOP, we know
4180 from the fact that OLD_BB is tree_empty_eh_handler_p that the
4181 variable is unchanged from input to the block and we can simply
4182 re-use the input to NEW_BB from the OLD_BB_OUT edge. */
4186 = gimple_phi_arg_location (nphi
, old_bb_out
->dest_idx
);
4187 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4188 redirect_edge_var_map_add (e
, nresult
, nop
, nloc
);
4192 /* Second, verify that all PHIs from OLD_BB have been handled. If not,
4193 we don't know what values from the other edges into NEW_BB to use. */
4194 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4196 gimple ophi
= gsi_stmt (ogsi
);
4197 tree oresult
= gimple_phi_result (ophi
);
4198 if (!bitmap_bit_p (ophi_handled
, SSA_NAME_VERSION (oresult
)))
4202 /* Finally, move the edges and update the PHIs. */
4203 for (ei
= ei_start (old_bb
->preds
); (e
= ei_safe_edge (ei
)); )
4204 if (e
->flags
& EDGE_EH
)
4206 /* ??? CFG manipluation routines do not try to update loop
4207 form on edge redirection. Do so manually here for now. */
4208 /* If we redirect a loop entry or latch edge that will either create
4209 a multiple entry loop or rotate the loop. If the loops merge
4210 we may have created a loop with multiple latches.
4211 All of this isn't easily fixed thus cancel the affected loop
4212 and mark the other loop as possibly having multiple latches. */
4213 if (e
->dest
== e
->dest
->loop_father
->header
)
4215 e
->dest
->loop_father
->header
= NULL
;
4216 e
->dest
->loop_father
->latch
= NULL
;
4217 new_bb
->loop_father
->latch
= NULL
;
4218 loops_state_set (LOOPS_NEED_FIXUP
|LOOPS_MAY_HAVE_MULTIPLE_LATCHES
);
4220 redirect_eh_edge_1 (e
, new_bb
, change_region
);
4221 redirect_edge_succ (e
, new_bb
);
4222 flush_pending_stmts (e
);
4227 BITMAP_FREE (ophi_handled
);
4231 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4232 redirect_edge_var_map_clear (e
);
4233 BITMAP_FREE (ophi_handled
);
4237 /* A subroutine of cleanup_empty_eh. Move a landing pad LP from its
4238 old region to NEW_REGION at BB. */
4241 cleanup_empty_eh_move_lp (basic_block bb
, edge e_out
,
4242 eh_landing_pad lp
, eh_region new_region
)
4244 gimple_stmt_iterator gsi
;
4247 for (pp
= &lp
->region
->landing_pads
; *pp
!= lp
; pp
= &(*pp
)->next_lp
)
4251 lp
->region
= new_region
;
4252 lp
->next_lp
= new_region
->landing_pads
;
4253 new_region
->landing_pads
= lp
;
4255 /* Delete the RESX that was matched within the empty handler block. */
4256 gsi
= gsi_last_bb (bb
);
4257 unlink_stmt_vdef (gsi_stmt (gsi
));
4258 gsi_remove (&gsi
, true);
4260 /* Clean up E_OUT for the fallthru. */
4261 e_out
->flags
= (e_out
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
4262 e_out
->probability
= REG_BR_PROB_BASE
;
4265 /* A subroutine of cleanup_empty_eh. Handle more complex cases of
4266 unsplitting than unsplit_eh was prepared to handle, e.g. when
4267 multiple incoming edges and phis are involved. */
4270 cleanup_empty_eh_unsplit (basic_block bb
, edge e_out
, eh_landing_pad lp
)
4272 gimple_stmt_iterator gsi
;
4275 /* We really ought not have totally lost everything following
4276 a landing pad label. Given that BB is empty, there had better
4278 gcc_assert (e_out
!= NULL
);
4280 /* The destination block must not already have a landing pad
4281 for a different region. */
4283 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4285 gimple stmt
= gsi_stmt (gsi
);
4288 if (gimple_code (stmt
) != GIMPLE_LABEL
)
4290 lab
= gimple_label_label (stmt
);
4291 lp_nr
= EH_LANDING_PAD_NR (lab
);
4292 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4296 /* Attempt to move the PHIs into the successor block. */
4297 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, false))
4299 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4301 "Unsplit EH landing pad %d to block %i "
4302 "(via cleanup_empty_eh).\n",
4303 lp
->index
, e_out
->dest
->index
);
4310 /* Return true if edge E_FIRST is part of an empty infinite loop
4311 or leads to such a loop through a series of single successor
4315 infinite_empty_loop_p (edge e_first
)
4317 bool inf_loop
= false;
4320 if (e_first
->dest
== e_first
->src
)
4323 e_first
->src
->aux
= (void *) 1;
4324 for (e
= e_first
; single_succ_p (e
->dest
); e
= single_succ_edge (e
->dest
))
4326 gimple_stmt_iterator gsi
;
4332 e
->dest
->aux
= (void *) 1;
4333 gsi
= gsi_after_labels (e
->dest
);
4334 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4335 gsi_next_nondebug (&gsi
);
4336 if (!gsi_end_p (gsi
))
4339 e_first
->src
->aux
= NULL
;
4340 for (e
= e_first
; e
->dest
->aux
; e
= single_succ_edge (e
->dest
))
4341 e
->dest
->aux
= NULL
;
4346 /* Examine the block associated with LP to determine if it's an empty
4347 handler for its EH region. If so, attempt to redirect EH edges to
4348 an outer region. Return true the CFG was updated in any way. This
4349 is similar to jump forwarding, just across EH edges. */
4352 cleanup_empty_eh (eh_landing_pad lp
)
4354 basic_block bb
= label_to_block (lp
->post_landing_pad
);
4355 gimple_stmt_iterator gsi
;
4357 eh_region new_region
;
4360 bool has_non_eh_pred
;
4364 /* There can be zero or one edges out of BB. This is the quickest test. */
4365 switch (EDGE_COUNT (bb
->succs
))
4371 e_out
= single_succ_edge (bb
);
4377 resx
= last_stmt (bb
);
4378 if (resx
&& is_gimple_resx (resx
))
4380 if (stmt_can_throw_external (resx
))
4381 optimize_clobbers (bb
);
4382 else if (sink_clobbers (bb
))
4386 gsi
= gsi_after_labels (bb
);
4388 /* Make sure to skip debug statements. */
4389 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4390 gsi_next_nondebug (&gsi
);
4392 /* If the block is totally empty, look for more unsplitting cases. */
4393 if (gsi_end_p (gsi
))
4395 /* For the degenerate case of an infinite loop bail out.
4396 If bb has no successors and is totally empty, which can happen e.g.
4397 because of incorrect noreturn attribute, bail out too. */
4399 || infinite_empty_loop_p (e_out
))
4402 return ret
| cleanup_empty_eh_unsplit (bb
, e_out
, lp
);
4405 /* The block should consist only of a single RESX statement, modulo a
4406 preceding call to __builtin_stack_restore if there is no outgoing
4407 edge, since the call can be eliminated in this case. */
4408 resx
= gsi_stmt (gsi
);
4409 if (!e_out
&& gimple_call_builtin_p (resx
, BUILT_IN_STACK_RESTORE
))
4412 resx
= gsi_stmt (gsi
);
4414 if (!is_gimple_resx (resx
))
4416 gcc_assert (gsi_one_before_end_p (gsi
));
4418 /* Determine if there are non-EH edges, or resx edges into the handler. */
4419 has_non_eh_pred
= false;
4420 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4421 if (!(e
->flags
& EDGE_EH
))
4422 has_non_eh_pred
= true;
4424 /* Find the handler that's outer of the empty handler by looking at
4425 where the RESX instruction was vectored. */
4426 new_lp_nr
= lookup_stmt_eh_lp (resx
);
4427 new_region
= get_eh_region_from_lp_number (new_lp_nr
);
4429 /* If there's no destination region within the current function,
4430 redirection is trivial via removing the throwing statements from
4431 the EH region, removing the EH edges, and allowing the block
4432 to go unreachable. */
4433 if (new_region
== NULL
)
4435 gcc_assert (e_out
== NULL
);
4436 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4437 if (e
->flags
& EDGE_EH
)
4439 gimple stmt
= last_stmt (e
->src
);
4440 remove_stmt_from_eh_lp (stmt
);
4448 /* If the destination region is a MUST_NOT_THROW, allow the runtime
4449 to handle the abort and allow the blocks to go unreachable. */
4450 if (new_region
->type
== ERT_MUST_NOT_THROW
)
4452 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4453 if (e
->flags
& EDGE_EH
)
4455 gimple stmt
= last_stmt (e
->src
);
4456 remove_stmt_from_eh_lp (stmt
);
4457 add_stmt_to_eh_lp (stmt
, new_lp_nr
);
4465 /* Try to redirect the EH edges and merge the PHIs into the destination
4466 landing pad block. If the merge succeeds, we'll already have redirected
4467 all the EH edges. The handler itself will go unreachable if there were
4469 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, true))
4472 /* Finally, if all input edges are EH edges, then we can (potentially)
4473 reduce the number of transfers from the runtime by moving the landing
4474 pad from the original region to the new region. This is a win when
4475 we remove the last CLEANUP region along a particular exception
4476 propagation path. Since nothing changes except for the region with
4477 which the landing pad is associated, the PHI nodes do not need to be
4479 if (!has_non_eh_pred
)
4481 cleanup_empty_eh_move_lp (bb
, e_out
, lp
, new_region
);
4482 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4483 fprintf (dump_file
, "Empty EH handler %i moved to EH region %i.\n",
4484 lp
->index
, new_region
->index
);
4486 /* ??? The CFG didn't change, but we may have rendered the
4487 old EH region unreachable. Trigger a cleanup there. */
4494 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4495 fprintf (dump_file
, "Empty EH handler %i removed.\n", lp
->index
);
4496 remove_eh_landing_pad (lp
);
4500 /* Do a post-order traversal of the EH region tree. Examine each
4501 post_landing_pad block and see if we can eliminate it as empty. */
4504 cleanup_all_empty_eh (void)
4506 bool changed
= false;
4510 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4512 changed
|= cleanup_empty_eh (lp
);
4517 /* Perform cleanups and lowering of exception handling
4518 1) cleanups regions with handlers doing nothing are optimized out
4519 2) MUST_NOT_THROW regions that became dead because of 1) are optimized out
4520 3) Info about regions that are containing instructions, and regions
4521 reachable via local EH edges is collected
4522 4) Eh tree is pruned for regions no longer necessary.
4524 TODO: Push MUST_NOT_THROW regions to the root of the EH tree.
4525 Unify those that have the same failure decl and locus.
4529 execute_cleanup_eh_1 (void)
4531 /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
4532 looking up unreachable landing pads. */
4533 remove_unreachable_handlers ();
4535 /* Watch out for the region tree vanishing due to all unreachable. */
4536 if (cfun
->eh
->region_tree
)
4538 bool changed
= false;
4541 changed
|= unsplit_all_eh ();
4542 changed
|= cleanup_all_empty_eh ();
4546 free_dominance_info (CDI_DOMINATORS
);
4547 free_dominance_info (CDI_POST_DOMINATORS
);
4549 /* We delayed all basic block deletion, as we may have performed
4550 cleanups on EH edges while non-EH edges were still present. */
4551 delete_unreachable_blocks ();
4553 /* We manipulated the landing pads. Remove any region that no
4554 longer has a landing pad. */
4555 remove_unreachable_handlers_no_lp ();
4557 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
4566 const pass_data pass_data_cleanup_eh
=
4568 GIMPLE_PASS
, /* type */
4569 "ehcleanup", /* name */
4570 OPTGROUP_NONE
, /* optinfo_flags */
4571 true, /* has_execute */
4572 TV_TREE_EH
, /* tv_id */
4573 PROP_gimple_lcf
, /* properties_required */
4574 0, /* properties_provided */
4575 0, /* properties_destroyed */
4576 0, /* todo_flags_start */
4577 0, /* todo_flags_finish */
4580 class pass_cleanup_eh
: public gimple_opt_pass
4583 pass_cleanup_eh (gcc::context
*ctxt
)
4584 : gimple_opt_pass (pass_data_cleanup_eh
, ctxt
)
4587 /* opt_pass methods: */
4588 opt_pass
* clone () { return new pass_cleanup_eh (m_ctxt
); }
4589 virtual bool gate (function
*fun
)
4591 return fun
->eh
!= NULL
&& fun
->eh
->region_tree
!= NULL
;
4594 virtual unsigned int execute (function
*);
4596 }; // class pass_cleanup_eh
4599 pass_cleanup_eh::execute (function
*fun
)
4601 int ret
= execute_cleanup_eh_1 ();
4603 /* If the function no longer needs an EH personality routine
4604 clear it. This exposes cross-language inlining opportunities
4605 and avoids references to a never defined personality routine. */
4606 if (DECL_FUNCTION_PERSONALITY (current_function_decl
)
4607 && function_needs_eh_personality (fun
) != eh_personality_lang
)
4608 DECL_FUNCTION_PERSONALITY (current_function_decl
) = NULL_TREE
;
4616 make_pass_cleanup_eh (gcc::context
*ctxt
)
4618 return new pass_cleanup_eh (ctxt
);
4621 /* Verify that BB containing STMT as the last statement, has precisely the
4622 edge that make_eh_edges would create. */
4625 verify_eh_edges (gimple stmt
)
4627 basic_block bb
= gimple_bb (stmt
);
4628 eh_landing_pad lp
= NULL
;
4633 lp_nr
= lookup_stmt_eh_lp (stmt
);
4635 lp
= get_eh_landing_pad_from_number (lp_nr
);
4638 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4640 if (e
->flags
& EDGE_EH
)
4644 error ("BB %i has multiple EH edges", bb
->index
);
4656 error ("BB %i can not throw but has an EH edge", bb
->index
);
4662 if (!stmt_could_throw_p (stmt
))
4664 error ("BB %i last statement has incorrectly set lp", bb
->index
);
4668 if (eh_edge
== NULL
)
4670 error ("BB %i is missing an EH edge", bb
->index
);
4674 if (eh_edge
->dest
!= label_to_block (lp
->post_landing_pad
))
4676 error ("Incorrect EH edge %i->%i", bb
->index
, eh_edge
->dest
->index
);
4683 /* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */
4686 verify_eh_dispatch_edge (gimple stmt
)
4690 basic_block src
, dst
;
4691 bool want_fallthru
= true;
4695 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
4696 src
= gimple_bb (stmt
);
4698 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4699 gcc_assert (e
->aux
== NULL
);
4704 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
4706 dst
= label_to_block (c
->label
);
4707 e
= find_edge (src
, dst
);
4710 error ("BB %i is missing an edge", src
->index
);
4715 /* A catch-all handler doesn't have a fallthru. */
4716 if (c
->type_list
== NULL
)
4718 want_fallthru
= false;
4724 case ERT_ALLOWED_EXCEPTIONS
:
4725 dst
= label_to_block (r
->u
.allowed
.label
);
4726 e
= find_edge (src
, dst
);
4729 error ("BB %i is missing an edge", src
->index
);
4740 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4742 if (e
->flags
& EDGE_FALLTHRU
)
4744 if (fall_edge
!= NULL
)
4746 error ("BB %i too many fallthru edges", src
->index
);
4755 error ("BB %i has incorrect edge", src
->index
);
4759 if ((fall_edge
!= NULL
) ^ want_fallthru
)
4761 error ("BB %i has incorrect fallthru edge", src
->index
);