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 sort_case_labels (case_label_vec
);
1555 /* Build the switch statement, setting last_case to be the default
1557 switch_stmt
= gimple_build_switch (finally_tmp
, last_case
,
1559 gimple_set_location (switch_stmt
, finally_loc
);
1561 /* Need to link SWITCH_STMT after running replace_goto_queue
1562 due to not wanting to process the same goto stmts twice. */
1563 gimple_seq_add_stmt (&tf
->top_p_seq
, switch_stmt
);
1564 gimple_seq_add_seq (&tf
->top_p_seq
, switch_body
);
1567 /* Decide whether or not we are going to duplicate the finally block.
1568 There are several considerations.
1570 First, if this is Java, then the finally block contains code
1571 written by the user. It has line numbers associated with it,
1572 so duplicating the block means it's difficult to set a breakpoint.
1573 Since controlling code generation via -g is verboten, we simply
1574 never duplicate code without optimization.
1576 Second, we'd like to prevent egregious code growth. One way to
1577 do this is to estimate the size of the finally block, multiply
1578 that by the number of copies we'd need to make, and compare against
1579 the estimate of the size of the switch machinery we'd have to add. */
1582 decide_copy_try_finally (int ndests
, bool may_throw
, gimple_seq finally
)
1584 int f_estimate
, sw_estimate
;
1587 /* If there's an EH_ELSE involved, the exception path is separate
1588 and really doesn't come into play for this computation. */
1589 eh_else
= get_eh_else (finally
);
1592 ndests
-= may_throw
;
1593 finally
= gimple_eh_else_n_body (eh_else
);
1598 gimple_stmt_iterator gsi
;
1603 for (gsi
= gsi_start (finally
); !gsi_end_p (gsi
); gsi_next (&gsi
))
1605 gimple stmt
= gsi_stmt (gsi
);
1606 if (!is_gimple_debug (stmt
) && !gimple_clobber_p (stmt
))
1612 /* Finally estimate N times, plus N gotos. */
1613 f_estimate
= count_insns_seq (finally
, &eni_size_weights
);
1614 f_estimate
= (f_estimate
+ 1) * ndests
;
1616 /* Switch statement (cost 10), N variable assignments, N gotos. */
1617 sw_estimate
= 10 + 2 * ndests
;
1619 /* Optimize for size clearly wants our best guess. */
1620 if (optimize_function_for_size_p (cfun
))
1621 return f_estimate
< sw_estimate
;
1623 /* ??? These numbers are completely made up so far. */
1625 return f_estimate
< 100 || f_estimate
< sw_estimate
* 2;
1627 return f_estimate
< 40 || f_estimate
* 2 < sw_estimate
* 3;
1630 /* REG is the enclosing region for a possible cleanup region, or the region
1631 itself. Returns TRUE if such a region would be unreachable.
1633 Cleanup regions within a must-not-throw region aren't actually reachable
1634 even if there are throwing stmts within them, because the personality
1635 routine will call terminate before unwinding. */
1638 cleanup_is_dead_in (eh_region reg
)
1640 while (reg
&& reg
->type
== ERT_CLEANUP
)
1642 return (reg
&& reg
->type
== ERT_MUST_NOT_THROW
);
1645 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_FINALLY nodes
1646 to a sequence of labels and blocks, plus the exception region trees
1647 that record all the magic. This is complicated by the need to
1648 arrange for the FINALLY block to be executed on all exits. */
1651 lower_try_finally (struct leh_state
*state
, gimple tp
)
1653 struct leh_tf_state this_tf
;
1654 struct leh_state this_state
;
1656 gimple_seq old_eh_seq
;
1658 /* Process the try block. */
1660 memset (&this_tf
, 0, sizeof (this_tf
));
1661 this_tf
.try_finally_expr
= tp
;
1663 this_tf
.outer
= state
;
1664 if (using_eh_for_cleanups_p () && !cleanup_is_dead_in (state
->cur_region
))
1666 this_tf
.region
= gen_eh_region_cleanup (state
->cur_region
);
1667 this_state
.cur_region
= this_tf
.region
;
1671 this_tf
.region
= NULL
;
1672 this_state
.cur_region
= state
->cur_region
;
1675 this_state
.ehp_region
= state
->ehp_region
;
1676 this_state
.tf
= &this_tf
;
1678 old_eh_seq
= eh_seq
;
1681 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1683 /* Determine if the try block is escaped through the bottom. */
1684 this_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1686 /* Determine if any exceptions are possible within the try block. */
1688 this_tf
.may_throw
= eh_region_may_contain_throw (this_tf
.region
);
1689 if (this_tf
.may_throw
)
1690 honor_protect_cleanup_actions (state
, &this_state
, &this_tf
);
1692 /* Determine how many edges (still) reach the finally block. Or rather,
1693 how many destinations are reached by the finally block. Use this to
1694 determine how we process the finally block itself. */
1696 ndests
= this_tf
.dest_array
.length ();
1697 ndests
+= this_tf
.may_fallthru
;
1698 ndests
+= this_tf
.may_return
;
1699 ndests
+= this_tf
.may_throw
;
1701 /* If the FINALLY block is not reachable, dike it out. */
1704 gimple_seq_add_seq (&this_tf
.top_p_seq
, gimple_try_eval (tp
));
1705 gimple_try_set_cleanup (tp
, NULL
);
1707 /* If the finally block doesn't fall through, then any destination
1708 we might try to impose there isn't reached either. There may be
1709 some minor amount of cleanup and redirection still needed. */
1710 else if (!gimple_seq_may_fallthru (gimple_try_cleanup (tp
)))
1711 lower_try_finally_nofallthru (state
, &this_tf
);
1713 /* We can easily special-case redirection to a single destination. */
1714 else if (ndests
== 1)
1715 lower_try_finally_onedest (state
, &this_tf
);
1716 else if (decide_copy_try_finally (ndests
, this_tf
.may_throw
,
1717 gimple_try_cleanup (tp
)))
1718 lower_try_finally_copy (state
, &this_tf
);
1720 lower_try_finally_switch (state
, &this_tf
);
1722 /* If someone requested we add a label at the end of the transformed
1724 if (this_tf
.fallthru_label
)
1726 /* This must be reached only if ndests == 0. */
1727 gimple x
= gimple_build_label (this_tf
.fallthru_label
);
1728 gimple_seq_add_stmt (&this_tf
.top_p_seq
, x
);
1731 this_tf
.dest_array
.release ();
1732 free (this_tf
.goto_queue
);
1733 if (this_tf
.goto_queue_map
)
1734 pointer_map_destroy (this_tf
.goto_queue_map
);
1736 /* If there was an old (aka outer) eh_seq, append the current eh_seq.
1737 If there was no old eh_seq, then the append is trivially already done. */
1741 eh_seq
= old_eh_seq
;
1744 gimple_seq new_eh_seq
= eh_seq
;
1745 eh_seq
= old_eh_seq
;
1746 gimple_seq_add_seq (&eh_seq
, new_eh_seq
);
1750 return this_tf
.top_p_seq
;
1753 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_CATCH with a
1754 list of GIMPLE_CATCH to a sequence of labels and blocks, plus the
1755 exception region trees that records all the magic. */
1758 lower_catch (struct leh_state
*state
, gimple tp
)
1760 eh_region try_region
= NULL
;
1761 struct leh_state this_state
= *state
;
1762 gimple_stmt_iterator gsi
;
1764 gimple_seq new_seq
, cleanup
;
1766 location_t try_catch_loc
= gimple_location (tp
);
1768 if (flag_exceptions
)
1770 try_region
= gen_eh_region_try (state
->cur_region
);
1771 this_state
.cur_region
= try_region
;
1774 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1776 if (!eh_region_may_contain_throw (try_region
))
1777 return gimple_try_eval (tp
);
1780 emit_eh_dispatch (&new_seq
, try_region
);
1781 emit_resx (&new_seq
, try_region
);
1783 this_state
.cur_region
= state
->cur_region
;
1784 this_state
.ehp_region
= try_region
;
1786 /* Add eh_seq from lowering EH in the cleanup sequence after the cleanup
1787 itself, so that e.g. for coverage purposes the nested cleanups don't
1788 appear before the cleanup body. See PR64634 for details. */
1789 gimple_seq old_eh_seq
= eh_seq
;
1793 cleanup
= gimple_try_cleanup (tp
);
1794 for (gsi
= gsi_start (cleanup
);
1802 gcatch
= gsi_stmt (gsi
);
1803 c
= gen_eh_region_catch (try_region
, gimple_catch_types (gcatch
));
1805 handler
= gimple_catch_handler (gcatch
);
1806 lower_eh_constructs_1 (&this_state
, &handler
);
1808 c
->label
= create_artificial_label (UNKNOWN_LOCATION
);
1809 x
= gimple_build_label (c
->label
);
1810 gimple_seq_add_stmt (&new_seq
, x
);
1812 gimple_seq_add_seq (&new_seq
, handler
);
1814 if (gimple_seq_may_fallthru (new_seq
))
1817 out_label
= create_artificial_label (try_catch_loc
);
1819 x
= gimple_build_goto (out_label
);
1820 gimple_seq_add_stmt (&new_seq
, x
);
1826 gimple_try_set_cleanup (tp
, new_seq
);
1828 gimple_seq new_eh_seq
= eh_seq
;
1829 eh_seq
= old_eh_seq
;
1830 gimple_seq ret_seq
= frob_into_branch_around (tp
, try_region
, out_label
);
1831 gimple_seq_add_seq (&eh_seq
, new_eh_seq
);
1835 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with a
1836 GIMPLE_EH_FILTER to a sequence of labels and blocks, plus the exception
1837 region trees that record all the magic. */
1840 lower_eh_filter (struct leh_state
*state
, gimple tp
)
1842 struct leh_state this_state
= *state
;
1843 eh_region this_region
= NULL
;
1847 inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1849 if (flag_exceptions
)
1851 this_region
= gen_eh_region_allowed (state
->cur_region
,
1852 gimple_eh_filter_types (inner
));
1853 this_state
.cur_region
= this_region
;
1856 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1858 if (!eh_region_may_contain_throw (this_region
))
1859 return gimple_try_eval (tp
);
1862 this_state
.cur_region
= state
->cur_region
;
1863 this_state
.ehp_region
= this_region
;
1865 emit_eh_dispatch (&new_seq
, this_region
);
1866 emit_resx (&new_seq
, this_region
);
1868 this_region
->u
.allowed
.label
= create_artificial_label (UNKNOWN_LOCATION
);
1869 x
= gimple_build_label (this_region
->u
.allowed
.label
);
1870 gimple_seq_add_stmt (&new_seq
, x
);
1872 lower_eh_constructs_1 (&this_state
, gimple_eh_filter_failure_ptr (inner
));
1873 gimple_seq_add_seq (&new_seq
, gimple_eh_filter_failure (inner
));
1875 gimple_try_set_cleanup (tp
, new_seq
);
1877 return frob_into_branch_around (tp
, this_region
, NULL
);
1880 /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with
1881 an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks,
1882 plus the exception region trees that record all the magic. */
1885 lower_eh_must_not_throw (struct leh_state
*state
, gimple tp
)
1887 struct leh_state this_state
= *state
;
1889 if (flag_exceptions
)
1891 gimple inner
= gimple_seq_first_stmt (gimple_try_cleanup (tp
));
1892 eh_region this_region
;
1894 this_region
= gen_eh_region_must_not_throw (state
->cur_region
);
1895 this_region
->u
.must_not_throw
.failure_decl
1896 = gimple_eh_must_not_throw_fndecl (inner
);
1897 this_region
->u
.must_not_throw
.failure_loc
1898 = LOCATION_LOCUS (gimple_location (tp
));
1900 /* In order to get mangling applied to this decl, we must mark it
1901 used now. Otherwise, pass_ipa_free_lang_data won't think it
1903 TREE_USED (this_region
->u
.must_not_throw
.failure_decl
) = 1;
1905 this_state
.cur_region
= this_region
;
1908 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1910 return gimple_try_eval (tp
);
1913 /* Implement a cleanup expression. This is similar to try-finally,
1914 except that we only execute the cleanup block for exception edges. */
1917 lower_cleanup (struct leh_state
*state
, gimple tp
)
1919 struct leh_state this_state
= *state
;
1920 eh_region this_region
= NULL
;
1921 struct leh_tf_state fake_tf
;
1923 bool cleanup_dead
= cleanup_is_dead_in (state
->cur_region
);
1925 if (flag_exceptions
&& !cleanup_dead
)
1927 this_region
= gen_eh_region_cleanup (state
->cur_region
);
1928 this_state
.cur_region
= this_region
;
1931 lower_eh_constructs_1 (&this_state
, gimple_try_eval_ptr (tp
));
1933 if (cleanup_dead
|| !eh_region_may_contain_throw (this_region
))
1934 return gimple_try_eval (tp
);
1936 /* Build enough of a try-finally state so that we can reuse
1937 honor_protect_cleanup_actions. */
1938 memset (&fake_tf
, 0, sizeof (fake_tf
));
1939 fake_tf
.top_p
= fake_tf
.try_finally_expr
= tp
;
1940 fake_tf
.outer
= state
;
1941 fake_tf
.region
= this_region
;
1942 fake_tf
.may_fallthru
= gimple_seq_may_fallthru (gimple_try_eval (tp
));
1943 fake_tf
.may_throw
= true;
1945 honor_protect_cleanup_actions (state
, NULL
, &fake_tf
);
1947 if (fake_tf
.may_throw
)
1949 /* In this case honor_protect_cleanup_actions had nothing to do,
1950 and we should process this normally. */
1951 lower_eh_constructs_1 (state
, gimple_try_cleanup_ptr (tp
));
1952 result
= frob_into_branch_around (tp
, this_region
,
1953 fake_tf
.fallthru_label
);
1957 /* In this case honor_protect_cleanup_actions did nearly all of
1958 the work. All we have left is to append the fallthru_label. */
1960 result
= gimple_try_eval (tp
);
1961 if (fake_tf
.fallthru_label
)
1963 gimple x
= gimple_build_label (fake_tf
.fallthru_label
);
1964 gimple_seq_add_stmt (&result
, x
);
1970 /* Main loop for lowering eh constructs. Also moves gsi to the next
1974 lower_eh_constructs_2 (struct leh_state
*state
, gimple_stmt_iterator
*gsi
)
1978 gimple stmt
= gsi_stmt (*gsi
);
1980 switch (gimple_code (stmt
))
1984 tree fndecl
= gimple_call_fndecl (stmt
);
1987 if (fndecl
&& DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
1988 switch (DECL_FUNCTION_CODE (fndecl
))
1990 case BUILT_IN_EH_POINTER
:
1991 /* The front end may have generated a call to
1992 __builtin_eh_pointer (0) within a catch region. Replace
1993 this zero argument with the current catch region number. */
1994 if (state
->ehp_region
)
1996 tree nr
= build_int_cst (integer_type_node
,
1997 state
->ehp_region
->index
);
1998 gimple_call_set_arg (stmt
, 0, nr
);
2002 /* The user has dome something silly. Remove it. */
2003 rhs
= null_pointer_node
;
2008 case BUILT_IN_EH_FILTER
:
2009 /* ??? This should never appear, but since it's a builtin it
2010 is accessible to abuse by users. Just remove it and
2011 replace the use with the arbitrary value zero. */
2012 rhs
= build_int_cst (TREE_TYPE (TREE_TYPE (fndecl
)), 0);
2014 lhs
= gimple_call_lhs (stmt
);
2015 x
= gimple_build_assign (lhs
, rhs
);
2016 gsi_insert_before (gsi
, x
, GSI_SAME_STMT
);
2019 case BUILT_IN_EH_COPY_VALUES
:
2020 /* Likewise this should not appear. Remove it. */
2021 gsi_remove (gsi
, true);
2031 /* If the stmt can throw use a new temporary for the assignment
2032 to a LHS. This makes sure the old value of the LHS is
2033 available on the EH edge. Only do so for statements that
2034 potentially fall through (no noreturn calls e.g.), otherwise
2035 this new assignment might create fake fallthru regions. */
2036 if (stmt_could_throw_p (stmt
)
2037 && gimple_has_lhs (stmt
)
2038 && gimple_stmt_may_fallthru (stmt
)
2039 && !tree_could_throw_p (gimple_get_lhs (stmt
))
2040 && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt
))))
2042 tree lhs
= gimple_get_lhs (stmt
);
2043 tree tmp
= create_tmp_var (TREE_TYPE (lhs
), NULL
);
2044 gimple s
= gimple_build_assign (lhs
, tmp
);
2045 gimple_set_location (s
, gimple_location (stmt
));
2046 gimple_set_block (s
, gimple_block (stmt
));
2047 gimple_set_lhs (stmt
, tmp
);
2048 if (TREE_CODE (TREE_TYPE (tmp
)) == COMPLEX_TYPE
2049 || TREE_CODE (TREE_TYPE (tmp
)) == VECTOR_TYPE
)
2050 DECL_GIMPLE_REG_P (tmp
) = 1;
2051 gsi_insert_after (gsi
, s
, GSI_SAME_STMT
);
2053 /* Look for things that can throw exceptions, and record them. */
2054 if (state
->cur_region
&& stmt_could_throw_p (stmt
))
2056 record_stmt_eh_region (state
->cur_region
, stmt
);
2057 note_eh_region_may_contain_throw (state
->cur_region
);
2064 maybe_record_in_goto_queue (state
, stmt
);
2068 verify_norecord_switch_expr (state
, stmt
);
2072 if (gimple_try_kind (stmt
) == GIMPLE_TRY_FINALLY
)
2073 replace
= lower_try_finally (state
, stmt
);
2076 x
= gimple_seq_first_stmt (gimple_try_cleanup (stmt
));
2079 replace
= gimple_try_eval (stmt
);
2080 lower_eh_constructs_1 (state
, &replace
);
2083 switch (gimple_code (x
))
2086 replace
= lower_catch (state
, stmt
);
2088 case GIMPLE_EH_FILTER
:
2089 replace
= lower_eh_filter (state
, stmt
);
2091 case GIMPLE_EH_MUST_NOT_THROW
:
2092 replace
= lower_eh_must_not_throw (state
, stmt
);
2094 case GIMPLE_EH_ELSE
:
2095 /* This code is only valid with GIMPLE_TRY_FINALLY. */
2098 replace
= lower_cleanup (state
, stmt
);
2103 /* Remove the old stmt and insert the transformed sequence
2105 gsi_insert_seq_before (gsi
, replace
, GSI_SAME_STMT
);
2106 gsi_remove (gsi
, true);
2108 /* Return since we don't want gsi_next () */
2111 case GIMPLE_EH_ELSE
:
2112 /* We should be eliminating this in lower_try_finally et al. */
2116 /* A type, a decl, or some kind of statement that we're not
2117 interested in. Don't walk them. */
2124 /* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */
2127 lower_eh_constructs_1 (struct leh_state
*state
, gimple_seq
*pseq
)
2129 gimple_stmt_iterator gsi
;
2130 for (gsi
= gsi_start (*pseq
); !gsi_end_p (gsi
);)
2131 lower_eh_constructs_2 (state
, &gsi
);
2135 lower_eh_constructs (void)
2137 struct leh_state null_state
;
2140 bodyp
= gimple_body (current_function_decl
);
2144 finally_tree
.create (31);
2145 eh_region_may_contain_throw_map
= BITMAP_ALLOC (NULL
);
2146 memset (&null_state
, 0, sizeof (null_state
));
2148 collect_finally_tree_1 (bodyp
, NULL
);
2149 lower_eh_constructs_1 (&null_state
, &bodyp
);
2150 gimple_set_body (current_function_decl
, bodyp
);
2152 /* We assume there's a return statement, or something, at the end of
2153 the function, and thus ploping the EH sequence afterward won't
2155 gcc_assert (!gimple_seq_may_fallthru (bodyp
));
2156 gimple_seq_add_seq (&bodyp
, eh_seq
);
2158 /* We assume that since BODYP already existed, adding EH_SEQ to it
2159 didn't change its value, and we don't have to re-set the function. */
2160 gcc_assert (bodyp
== gimple_body (current_function_decl
));
2162 finally_tree
.dispose ();
2163 BITMAP_FREE (eh_region_may_contain_throw_map
);
2166 /* If this function needs a language specific EH personality routine
2167 and the frontend didn't already set one do so now. */
2168 if (function_needs_eh_personality (cfun
) == eh_personality_lang
2169 && !DECL_FUNCTION_PERSONALITY (current_function_decl
))
2170 DECL_FUNCTION_PERSONALITY (current_function_decl
)
2171 = lang_hooks
.eh_personality ();
2178 const pass_data pass_data_lower_eh
=
2180 GIMPLE_PASS
, /* type */
2182 OPTGROUP_NONE
, /* optinfo_flags */
2183 false, /* has_gate */
2184 true, /* has_execute */
2185 TV_TREE_EH
, /* tv_id */
2186 PROP_gimple_lcf
, /* properties_required */
2187 PROP_gimple_leh
, /* properties_provided */
2188 0, /* properties_destroyed */
2189 0, /* todo_flags_start */
2190 0, /* todo_flags_finish */
2193 class pass_lower_eh
: public gimple_opt_pass
2196 pass_lower_eh (gcc::context
*ctxt
)
2197 : gimple_opt_pass (pass_data_lower_eh
, ctxt
)
2200 /* opt_pass methods: */
2201 unsigned int execute () { return lower_eh_constructs (); }
2203 }; // class pass_lower_eh
2208 make_pass_lower_eh (gcc::context
*ctxt
)
2210 return new pass_lower_eh (ctxt
);
2213 /* Create the multiple edges from an EH_DISPATCH statement to all of
2214 the possible handlers for its EH region. Return true if there's
2215 no fallthru edge; false if there is. */
2218 make_eh_dispatch_edges (gimple stmt
)
2222 basic_block src
, dst
;
2224 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2225 src
= gimple_bb (stmt
);
2230 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2232 dst
= label_to_block (c
->label
);
2233 make_edge (src
, dst
, 0);
2235 /* A catch-all handler doesn't have a fallthru. */
2236 if (c
->type_list
== NULL
)
2241 case ERT_ALLOWED_EXCEPTIONS
:
2242 dst
= label_to_block (r
->u
.allowed
.label
);
2243 make_edge (src
, dst
, 0);
2253 /* Create the single EH edge from STMT to its nearest landing pad,
2254 if there is such a landing pad within the current function. */
2257 make_eh_edges (gimple stmt
)
2259 basic_block src
, dst
;
2263 lp_nr
= lookup_stmt_eh_lp (stmt
);
2267 lp
= get_eh_landing_pad_from_number (lp_nr
);
2268 gcc_assert (lp
!= NULL
);
2270 src
= gimple_bb (stmt
);
2271 dst
= label_to_block (lp
->post_landing_pad
);
2272 make_edge (src
, dst
, EDGE_EH
);
2275 /* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
2276 do not actually perform the final edge redirection.
2278 CHANGE_REGION is true when we're being called from cleanup_empty_eh and
2279 we intend to change the destination EH region as well; this means
2280 EH_LANDING_PAD_NR must already be set on the destination block label.
2281 If false, we're being called from generic cfg manipulation code and we
2282 should preserve our place within the region tree. */
2285 redirect_eh_edge_1 (edge edge_in
, basic_block new_bb
, bool change_region
)
2287 eh_landing_pad old_lp
, new_lp
;
2290 int old_lp_nr
, new_lp_nr
;
2291 tree old_label
, new_label
;
2295 old_bb
= edge_in
->dest
;
2296 old_label
= gimple_block_label (old_bb
);
2297 old_lp_nr
= EH_LANDING_PAD_NR (old_label
);
2298 gcc_assert (old_lp_nr
> 0);
2299 old_lp
= get_eh_landing_pad_from_number (old_lp_nr
);
2301 throw_stmt
= last_stmt (edge_in
->src
);
2302 gcc_assert (lookup_stmt_eh_lp (throw_stmt
) == old_lp_nr
);
2304 new_label
= gimple_block_label (new_bb
);
2306 /* Look for an existing region that might be using NEW_BB already. */
2307 new_lp_nr
= EH_LANDING_PAD_NR (new_label
);
2310 new_lp
= get_eh_landing_pad_from_number (new_lp_nr
);
2311 gcc_assert (new_lp
);
2313 /* Unless CHANGE_REGION is true, the new and old landing pad
2314 had better be associated with the same EH region. */
2315 gcc_assert (change_region
|| new_lp
->region
== old_lp
->region
);
2320 gcc_assert (!change_region
);
2323 /* Notice when we redirect the last EH edge away from OLD_BB. */
2324 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
2325 if (e
!= edge_in
&& (e
->flags
& EDGE_EH
))
2330 /* NEW_LP already exists. If there are still edges into OLD_LP,
2331 there's nothing to do with the EH tree. If there are no more
2332 edges into OLD_LP, then we want to remove OLD_LP as it is unused.
2333 If CHANGE_REGION is true, then our caller is expecting to remove
2335 if (e
== NULL
&& !change_region
)
2336 remove_eh_landing_pad (old_lp
);
2340 /* No correct landing pad exists. If there are no more edges
2341 into OLD_LP, then we can simply re-use the existing landing pad.
2342 Otherwise, we have to create a new landing pad. */
2345 EH_LANDING_PAD_NR (old_lp
->post_landing_pad
) = 0;
2349 new_lp
= gen_eh_landing_pad (old_lp
->region
);
2350 new_lp
->post_landing_pad
= new_label
;
2351 EH_LANDING_PAD_NR (new_label
) = new_lp
->index
;
2354 /* Maybe move the throwing statement to the new region. */
2355 if (old_lp
!= new_lp
)
2357 remove_stmt_from_eh_lp (throw_stmt
);
2358 add_stmt_to_eh_lp (throw_stmt
, new_lp
->index
);
2362 /* Redirect EH edge E to NEW_BB. */
2365 redirect_eh_edge (edge edge_in
, basic_block new_bb
)
2367 redirect_eh_edge_1 (edge_in
, new_bb
, false);
2368 return ssa_redirect_edge (edge_in
, new_bb
);
2371 /* This is a subroutine of gimple_redirect_edge_and_branch. Update the
2372 labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
2373 The actual edge update will happen in the caller. */
2376 redirect_eh_dispatch_edge (gimple stmt
, edge e
, basic_block new_bb
)
2378 tree new_lab
= gimple_block_label (new_bb
);
2379 bool any_changed
= false;
2384 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
2388 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
2390 old_bb
= label_to_block (c
->label
);
2391 if (old_bb
== e
->dest
)
2399 case ERT_ALLOWED_EXCEPTIONS
:
2400 old_bb
= label_to_block (r
->u
.allowed
.label
);
2401 gcc_assert (old_bb
== e
->dest
);
2402 r
->u
.allowed
.label
= new_lab
;
2410 gcc_assert (any_changed
);
2413 /* Helper function for operation_could_trap_p and stmt_could_throw_p. */
2416 operation_could_trap_helper_p (enum tree_code op
,
2427 case TRUNC_DIV_EXPR
:
2429 case FLOOR_DIV_EXPR
:
2430 case ROUND_DIV_EXPR
:
2431 case EXACT_DIV_EXPR
:
2433 case FLOOR_MOD_EXPR
:
2434 case ROUND_MOD_EXPR
:
2435 case TRUNC_MOD_EXPR
:
2437 if (honor_snans
|| honor_trapv
)
2440 return flag_trapping_math
;
2441 if (!TREE_CONSTANT (divisor
) || integer_zerop (divisor
))
2450 /* Some floating point comparisons may trap. */
2455 case UNORDERED_EXPR
:
2465 case FIX_TRUNC_EXPR
:
2466 /* Conversion of floating point might trap. */
2472 /* These operations don't trap with floating point. */
2480 /* Any floating arithmetic may trap. */
2481 if (fp_operation
&& flag_trapping_math
)
2489 /* Constructing an object cannot trap. */
2493 /* Any floating arithmetic may trap. */
2494 if (fp_operation
&& flag_trapping_math
)
2502 /* Return true if operation OP may trap. FP_OPERATION is true if OP is applied
2503 on floating-point values. HONOR_TRAPV is true if OP is applied on integer
2504 type operands that may trap. If OP is a division operator, DIVISOR contains
2505 the value of the divisor. */
2508 operation_could_trap_p (enum tree_code op
, bool fp_operation
, bool honor_trapv
,
2511 bool honor_nans
= (fp_operation
&& flag_trapping_math
2512 && !flag_finite_math_only
);
2513 bool honor_snans
= fp_operation
&& flag_signaling_nans
!= 0;
2516 if (TREE_CODE_CLASS (op
) != tcc_comparison
2517 && TREE_CODE_CLASS (op
) != tcc_unary
2518 && TREE_CODE_CLASS (op
) != tcc_binary
)
2521 return operation_could_trap_helper_p (op
, fp_operation
, honor_trapv
,
2522 honor_nans
, honor_snans
, divisor
,
2527 /* Returns true if it is possible to prove that the index of
2528 an array access REF (an ARRAY_REF expression) falls into the
2532 in_array_bounds_p (tree ref
)
2534 tree idx
= TREE_OPERAND (ref
, 1);
2537 if (TREE_CODE (idx
) != INTEGER_CST
)
2540 min
= array_ref_low_bound (ref
);
2541 max
= array_ref_up_bound (ref
);
2544 || TREE_CODE (min
) != INTEGER_CST
2545 || TREE_CODE (max
) != INTEGER_CST
)
2548 if (tree_int_cst_lt (idx
, min
)
2549 || tree_int_cst_lt (max
, idx
))
2555 /* Returns true if it is possible to prove that the range of
2556 an array access REF (an ARRAY_RANGE_REF expression) falls
2557 into the array bounds. */
2560 range_in_array_bounds_p (tree ref
)
2562 tree domain_type
= TYPE_DOMAIN (TREE_TYPE (ref
));
2563 tree range_min
, range_max
, min
, max
;
2565 range_min
= TYPE_MIN_VALUE (domain_type
);
2566 range_max
= TYPE_MAX_VALUE (domain_type
);
2569 || TREE_CODE (range_min
) != INTEGER_CST
2570 || TREE_CODE (range_max
) != INTEGER_CST
)
2573 min
= array_ref_low_bound (ref
);
2574 max
= array_ref_up_bound (ref
);
2577 || TREE_CODE (min
) != INTEGER_CST
2578 || TREE_CODE (max
) != INTEGER_CST
)
2581 if (tree_int_cst_lt (range_min
, min
)
2582 || tree_int_cst_lt (max
, range_max
))
2588 /* Return true if EXPR can trap, as in dereferencing an invalid pointer
2589 location or floating point arithmetic. C.f. the rtl version, may_trap_p.
2590 This routine expects only GIMPLE lhs or rhs input. */
2593 tree_could_trap_p (tree expr
)
2595 enum tree_code code
;
2596 bool fp_operation
= false;
2597 bool honor_trapv
= false;
2598 tree t
, base
, div
= NULL_TREE
;
2603 code
= TREE_CODE (expr
);
2604 t
= TREE_TYPE (expr
);
2608 if (COMPARISON_CLASS_P (expr
))
2609 fp_operation
= FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 0)));
2611 fp_operation
= FLOAT_TYPE_P (t
);
2612 honor_trapv
= INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
);
2615 if (TREE_CODE_CLASS (code
) == tcc_binary
)
2616 div
= TREE_OPERAND (expr
, 1);
2617 if (operation_could_trap_p (code
, fp_operation
, honor_trapv
, div
))
2627 case VIEW_CONVERT_EXPR
:
2628 case WITH_SIZE_EXPR
:
2629 expr
= TREE_OPERAND (expr
, 0);
2630 code
= TREE_CODE (expr
);
2633 case ARRAY_RANGE_REF
:
2634 base
= TREE_OPERAND (expr
, 0);
2635 if (tree_could_trap_p (base
))
2637 if (TREE_THIS_NOTRAP (expr
))
2639 return !range_in_array_bounds_p (expr
);
2642 base
= TREE_OPERAND (expr
, 0);
2643 if (tree_could_trap_p (base
))
2645 if (TREE_THIS_NOTRAP (expr
))
2647 return !in_array_bounds_p (expr
);
2649 case TARGET_MEM_REF
:
2651 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
2652 && tree_could_trap_p (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
2654 if (TREE_THIS_NOTRAP (expr
))
2656 /* We cannot prove that the access is in-bounds when we have
2657 variable-index TARGET_MEM_REFs. */
2658 if (code
== TARGET_MEM_REF
2659 && (TMR_INDEX (expr
) || TMR_INDEX2 (expr
)))
2661 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
)
2663 tree base
= TREE_OPERAND (TREE_OPERAND (expr
, 0), 0);
2664 double_int off
= mem_ref_offset (expr
);
2665 if (off
.is_negative ())
2667 if (TREE_CODE (base
) == STRING_CST
)
2668 return double_int::from_uhwi (TREE_STRING_LENGTH (base
)).ule (off
);
2669 else if (DECL_SIZE_UNIT (base
) == NULL_TREE
2670 || TREE_CODE (DECL_SIZE_UNIT (base
)) != INTEGER_CST
2671 || tree_to_double_int (DECL_SIZE_UNIT (base
)).ule (off
))
2673 /* Now we are sure the first byte of the access is inside
2680 return !TREE_THIS_NOTRAP (expr
);
2683 return TREE_THIS_VOLATILE (expr
);
2686 t
= get_callee_fndecl (expr
);
2687 /* Assume that calls to weak functions may trap. */
2688 if (!t
|| !DECL_P (t
))
2691 return tree_could_trap_p (t
);
2695 /* Assume that accesses to weak functions may trap, unless we know
2696 they are certainly defined in current TU or in some other
2698 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
))
2700 struct cgraph_node
*node
;
2701 if (!DECL_EXTERNAL (expr
))
2703 node
= cgraph_function_node (cgraph_get_node (expr
), NULL
);
2704 if (node
&& node
->in_other_partition
)
2711 /* Assume that accesses to weak vars may trap, unless we know
2712 they are certainly defined in current TU or in some other
2714 if (DECL_WEAK (expr
) && !DECL_COMDAT (expr
))
2717 if (!DECL_EXTERNAL (expr
))
2719 node
= varpool_variable_node (varpool_get_node (expr
), NULL
);
2720 if (node
&& node
->in_other_partition
)
2732 /* Helper for stmt_could_throw_p. Return true if STMT (assumed to be a
2733 an assignment or a conditional) may throw. */
2736 stmt_could_throw_1_p (gimple stmt
)
2738 enum tree_code code
= gimple_expr_code (stmt
);
2739 bool honor_nans
= false;
2740 bool honor_snans
= false;
2741 bool fp_operation
= false;
2742 bool honor_trapv
= false;
2747 if (TREE_CODE_CLASS (code
) == tcc_comparison
2748 || TREE_CODE_CLASS (code
) == tcc_unary
2749 || TREE_CODE_CLASS (code
) == tcc_binary
)
2751 if (is_gimple_assign (stmt
)
2752 && TREE_CODE_CLASS (code
) == tcc_comparison
)
2753 t
= TREE_TYPE (gimple_assign_rhs1 (stmt
));
2754 else if (gimple_code (stmt
) == GIMPLE_COND
)
2755 t
= TREE_TYPE (gimple_cond_lhs (stmt
));
2757 t
= gimple_expr_type (stmt
);
2758 fp_operation
= FLOAT_TYPE_P (t
);
2761 honor_nans
= flag_trapping_math
&& !flag_finite_math_only
;
2762 honor_snans
= flag_signaling_nans
!= 0;
2764 else if (INTEGRAL_TYPE_P (t
) && TYPE_OVERFLOW_TRAPS (t
))
2768 /* Check if the main expression may trap. */
2769 t
= is_gimple_assign (stmt
) ? gimple_assign_rhs2 (stmt
) : NULL
;
2770 ret
= operation_could_trap_helper_p (code
, fp_operation
, honor_trapv
,
2771 honor_nans
, honor_snans
, t
,
2776 /* If the expression does not trap, see if any of the individual operands may
2778 for (i
= 0; i
< gimple_num_ops (stmt
); i
++)
2779 if (tree_could_trap_p (gimple_op (stmt
, i
)))
2786 /* Return true if statement STMT could throw an exception. */
2789 stmt_could_throw_p (gimple stmt
)
2791 if (!flag_exceptions
)
2794 /* The only statements that can throw an exception are assignments,
2795 conditionals, calls, resx, and asms. */
2796 switch (gimple_code (stmt
))
2802 return !gimple_call_nothrow_p (stmt
);
2806 if (!cfun
->can_throw_non_call_exceptions
)
2808 return stmt_could_throw_1_p (stmt
);
2811 if (!cfun
->can_throw_non_call_exceptions
)
2813 return gimple_asm_volatile_p (stmt
);
2821 /* Return true if expression T could throw an exception. */
2824 tree_could_throw_p (tree t
)
2826 if (!flag_exceptions
)
2828 if (TREE_CODE (t
) == MODIFY_EXPR
)
2830 if (cfun
->can_throw_non_call_exceptions
2831 && tree_could_trap_p (TREE_OPERAND (t
, 0)))
2833 t
= TREE_OPERAND (t
, 1);
2836 if (TREE_CODE (t
) == WITH_SIZE_EXPR
)
2837 t
= TREE_OPERAND (t
, 0);
2838 if (TREE_CODE (t
) == CALL_EXPR
)
2839 return (call_expr_flags (t
) & ECF_NOTHROW
) == 0;
2840 if (cfun
->can_throw_non_call_exceptions
)
2841 return tree_could_trap_p (t
);
2845 /* Return true if STMT can throw an exception that is not caught within
2846 the current function (CFUN). */
2849 stmt_can_throw_external (gimple stmt
)
2853 if (!stmt_could_throw_p (stmt
))
2856 lp_nr
= lookup_stmt_eh_lp (stmt
);
2860 /* Return true if STMT can throw an exception that is caught within
2861 the current function (CFUN). */
2864 stmt_can_throw_internal (gimple stmt
)
2868 if (!stmt_could_throw_p (stmt
))
2871 lp_nr
= lookup_stmt_eh_lp (stmt
);
2875 /* Given a statement STMT in IFUN, if STMT can no longer throw, then
2876 remove any entry it might have from the EH table. Return true if
2877 any change was made. */
2880 maybe_clean_eh_stmt_fn (struct function
*ifun
, gimple stmt
)
2882 if (stmt_could_throw_p (stmt
))
2884 return remove_stmt_from_eh_lp_fn (ifun
, stmt
);
2887 /* Likewise, but always use the current function. */
2890 maybe_clean_eh_stmt (gimple stmt
)
2892 return maybe_clean_eh_stmt_fn (cfun
, stmt
);
2895 /* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
2896 OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
2897 in the table if it should be in there. Return TRUE if a replacement was
2898 done that my require an EH edge purge. */
2901 maybe_clean_or_replace_eh_stmt (gimple old_stmt
, gimple new_stmt
)
2903 int lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2907 bool new_stmt_could_throw
= stmt_could_throw_p (new_stmt
);
2909 if (new_stmt
== old_stmt
&& new_stmt_could_throw
)
2912 remove_stmt_from_eh_lp (old_stmt
);
2913 if (new_stmt_could_throw
)
2915 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
2925 /* Given a statement OLD_STMT in OLD_FUN and a duplicate statement NEW_STMT
2926 in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT. The MAP
2927 operand is the return value of duplicate_eh_regions. */
2930 maybe_duplicate_eh_stmt_fn (struct function
*new_fun
, gimple new_stmt
,
2931 struct function
*old_fun
, gimple old_stmt
,
2932 struct pointer_map_t
*map
, int default_lp_nr
)
2934 int old_lp_nr
, new_lp_nr
;
2937 if (!stmt_could_throw_p (new_stmt
))
2940 old_lp_nr
= lookup_stmt_eh_lp_fn (old_fun
, old_stmt
);
2943 if (default_lp_nr
== 0)
2945 new_lp_nr
= default_lp_nr
;
2947 else if (old_lp_nr
> 0)
2949 eh_landing_pad old_lp
, new_lp
;
2951 old_lp
= (*old_fun
->eh
->lp_array
)[old_lp_nr
];
2952 slot
= pointer_map_contains (map
, old_lp
);
2953 new_lp
= (eh_landing_pad
) *slot
;
2954 new_lp_nr
= new_lp
->index
;
2958 eh_region old_r
, new_r
;
2960 old_r
= (*old_fun
->eh
->region_array
)[-old_lp_nr
];
2961 slot
= pointer_map_contains (map
, old_r
);
2962 new_r
= (eh_region
) *slot
;
2963 new_lp_nr
= -new_r
->index
;
2966 add_stmt_to_eh_lp_fn (new_fun
, new_stmt
, new_lp_nr
);
2970 /* Similar, but both OLD_STMT and NEW_STMT are within the current function,
2971 and thus no remapping is required. */
2974 maybe_duplicate_eh_stmt (gimple new_stmt
, gimple old_stmt
)
2978 if (!stmt_could_throw_p (new_stmt
))
2981 lp_nr
= lookup_stmt_eh_lp (old_stmt
);
2985 add_stmt_to_eh_lp (new_stmt
, lp_nr
);
2989 /* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of
2990 GIMPLE_TRY) that are similar enough to be considered the same. Currently
2991 this only handles handlers consisting of a single call, as that's the
2992 important case for C++: a destructor call for a particular object showing
2993 up in multiple handlers. */
2996 same_handler_p (gimple_seq oneh
, gimple_seq twoh
)
2998 gimple_stmt_iterator gsi
;
3002 gsi
= gsi_start (oneh
);
3003 if (!gsi_one_before_end_p (gsi
))
3005 ones
= gsi_stmt (gsi
);
3007 gsi
= gsi_start (twoh
);
3008 if (!gsi_one_before_end_p (gsi
))
3010 twos
= gsi_stmt (gsi
);
3012 if (!is_gimple_call (ones
)
3013 || !is_gimple_call (twos
)
3014 || gimple_call_lhs (ones
)
3015 || gimple_call_lhs (twos
)
3016 || gimple_call_chain (ones
)
3017 || gimple_call_chain (twos
)
3018 || !gimple_call_same_target_p (ones
, twos
)
3019 || gimple_call_num_args (ones
) != gimple_call_num_args (twos
))
3022 for (ai
= 0; ai
< gimple_call_num_args (ones
); ++ai
)
3023 if (!operand_equal_p (gimple_call_arg (ones
, ai
),
3024 gimple_call_arg (twos
, ai
), 0))
3031 try { A() } finally { try { ~B() } catch { ~A() } }
3032 try { ... } finally { ~A() }
3034 try { A() } catch { ~B() }
3035 try { ~B() ... } finally { ~A() }
3037 This occurs frequently in C++, where A is a local variable and B is a
3038 temporary used in the initializer for A. */
3041 optimize_double_finally (gimple one
, gimple two
)
3044 gimple_stmt_iterator gsi
;
3047 cleanup
= gimple_try_cleanup (one
);
3048 gsi
= gsi_start (cleanup
);
3049 if (!gsi_one_before_end_p (gsi
))
3052 oneh
= gsi_stmt (gsi
);
3053 if (gimple_code (oneh
) != GIMPLE_TRY
3054 || gimple_try_kind (oneh
) != GIMPLE_TRY_CATCH
)
3057 if (same_handler_p (gimple_try_cleanup (oneh
), gimple_try_cleanup (two
)))
3059 gimple_seq seq
= gimple_try_eval (oneh
);
3061 gimple_try_set_cleanup (one
, seq
);
3062 gimple_try_set_kind (one
, GIMPLE_TRY_CATCH
);
3063 seq
= copy_gimple_seq_and_replace_locals (seq
);
3064 gimple_seq_add_seq (&seq
, gimple_try_eval (two
));
3065 gimple_try_set_eval (two
, seq
);
3069 /* Perform EH refactoring optimizations that are simpler to do when code
3070 flow has been lowered but EH structures haven't. */
3073 refactor_eh_r (gimple_seq seq
)
3075 gimple_stmt_iterator gsi
;
3080 gsi
= gsi_start (seq
);
3084 if (gsi_end_p (gsi
))
3087 two
= gsi_stmt (gsi
);
3090 && gimple_code (one
) == GIMPLE_TRY
3091 && gimple_code (two
) == GIMPLE_TRY
3092 && gimple_try_kind (one
) == GIMPLE_TRY_FINALLY
3093 && gimple_try_kind (two
) == GIMPLE_TRY_FINALLY
)
3094 optimize_double_finally (one
, two
);
3096 switch (gimple_code (one
))
3099 refactor_eh_r (gimple_try_eval (one
));
3100 refactor_eh_r (gimple_try_cleanup (one
));
3103 refactor_eh_r (gimple_catch_handler (one
));
3105 case GIMPLE_EH_FILTER
:
3106 refactor_eh_r (gimple_eh_filter_failure (one
));
3108 case GIMPLE_EH_ELSE
:
3109 refactor_eh_r (gimple_eh_else_n_body (one
));
3110 refactor_eh_r (gimple_eh_else_e_body (one
));
3125 refactor_eh_r (gimple_body (current_function_decl
));
3130 gate_refactor_eh (void)
3132 return flag_exceptions
!= 0;
3137 const pass_data pass_data_refactor_eh
=
3139 GIMPLE_PASS
, /* type */
3141 OPTGROUP_NONE
, /* optinfo_flags */
3142 true, /* has_gate */
3143 true, /* has_execute */
3144 TV_TREE_EH
, /* tv_id */
3145 PROP_gimple_lcf
, /* properties_required */
3146 0, /* properties_provided */
3147 0, /* properties_destroyed */
3148 0, /* todo_flags_start */
3149 0, /* todo_flags_finish */
3152 class pass_refactor_eh
: public gimple_opt_pass
3155 pass_refactor_eh (gcc::context
*ctxt
)
3156 : gimple_opt_pass (pass_data_refactor_eh
, ctxt
)
3159 /* opt_pass methods: */
3160 bool gate () { return gate_refactor_eh (); }
3161 unsigned int execute () { return refactor_eh (); }
3163 }; // class pass_refactor_eh
3168 make_pass_refactor_eh (gcc::context
*ctxt
)
3170 return new pass_refactor_eh (ctxt
);
3173 /* At the end of gimple optimization, we can lower RESX. */
3176 lower_resx (basic_block bb
, gimple stmt
, struct pointer_map_t
*mnt_map
)
3179 eh_region src_r
, dst_r
;
3180 gimple_stmt_iterator gsi
;
3185 lp_nr
= lookup_stmt_eh_lp (stmt
);
3187 dst_r
= get_eh_region_from_lp_number (lp_nr
);
3191 src_r
= get_eh_region_from_number (gimple_resx_region (stmt
));
3192 gsi
= gsi_last_bb (bb
);
3196 /* We can wind up with no source region when pass_cleanup_eh shows
3197 that there are no entries into an eh region and deletes it, but
3198 then the block that contains the resx isn't removed. This can
3199 happen without optimization when the switch statement created by
3200 lower_try_finally_switch isn't simplified to remove the eh case.
3202 Resolve this by expanding the resx node to an abort. */
3204 fn
= builtin_decl_implicit (BUILT_IN_TRAP
);
3205 x
= gimple_build_call (fn
, 0);
3206 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3208 while (EDGE_COUNT (bb
->succs
) > 0)
3209 remove_edge (EDGE_SUCC (bb
, 0));
3213 /* When we have a destination region, we resolve this by copying
3214 the excptr and filter values into place, and changing the edge
3215 to immediately after the landing pad. */
3224 /* We are resuming into a MUST_NOT_CALL region. Expand a call to
3225 the failure decl into a new block, if needed. */
3226 gcc_assert (dst_r
->type
== ERT_MUST_NOT_THROW
);
3228 slot
= pointer_map_contains (mnt_map
, dst_r
);
3231 gimple_stmt_iterator gsi2
;
3233 new_bb
= create_empty_bb (bb
);
3235 add_bb_to_loop (new_bb
, bb
->loop_father
);
3236 lab
= gimple_block_label (new_bb
);
3237 gsi2
= gsi_start_bb (new_bb
);
3239 fn
= dst_r
->u
.must_not_throw
.failure_decl
;
3240 x
= gimple_build_call (fn
, 0);
3241 gimple_set_location (x
, dst_r
->u
.must_not_throw
.failure_loc
);
3242 gsi_insert_after (&gsi2
, x
, GSI_CONTINUE_LINKING
);
3244 slot
= pointer_map_insert (mnt_map
, dst_r
);
3250 new_bb
= label_to_block (lab
);
3253 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3254 e
= make_edge (bb
, new_bb
, EDGE_FALLTHRU
);
3255 e
->count
= bb
->count
;
3256 e
->probability
= REG_BR_PROB_BASE
;
3261 tree dst_nr
= build_int_cst (integer_type_node
, dst_r
->index
);
3263 fn
= builtin_decl_implicit (BUILT_IN_EH_COPY_VALUES
);
3264 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3265 x
= gimple_build_call (fn
, 2, dst_nr
, src_nr
);
3266 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3268 /* Update the flags for the outgoing edge. */
3269 e
= single_succ_edge (bb
);
3270 gcc_assert (e
->flags
& EDGE_EH
);
3271 e
->flags
= (e
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
3273 /* If there are no more EH users of the landing pad, delete it. */
3274 FOR_EACH_EDGE (e
, ei
, e
->dest
->preds
)
3275 if (e
->flags
& EDGE_EH
)
3279 eh_landing_pad lp
= get_eh_landing_pad_from_number (lp_nr
);
3280 remove_eh_landing_pad (lp
);
3290 /* When we don't have a destination region, this exception escapes
3291 up the call chain. We resolve this by generating a call to the
3292 _Unwind_Resume library function. */
3294 /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup
3295 with no arguments for C++ and Java. Check for that. */
3296 if (src_r
->use_cxa_end_cleanup
)
3298 fn
= builtin_decl_implicit (BUILT_IN_CXA_END_CLEANUP
);
3299 x
= gimple_build_call (fn
, 0);
3300 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3304 fn
= builtin_decl_implicit (BUILT_IN_EH_POINTER
);
3305 src_nr
= build_int_cst (integer_type_node
, src_r
->index
);
3306 x
= gimple_build_call (fn
, 1, src_nr
);
3307 var
= create_tmp_var (ptr_type_node
, NULL
);
3308 var
= make_ssa_name (var
, x
);
3309 gimple_call_set_lhs (x
, var
);
3310 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3312 fn
= builtin_decl_implicit (BUILT_IN_UNWIND_RESUME
);
3313 x
= gimple_build_call (fn
, 1, var
);
3314 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3317 gcc_assert (EDGE_COUNT (bb
->succs
) == 0);
3320 gsi_remove (&gsi
, true);
3326 execute_lower_resx (void)
3329 struct pointer_map_t
*mnt_map
;
3330 bool dominance_invalidated
= false;
3331 bool any_rewritten
= false;
3333 mnt_map
= pointer_map_create ();
3335 FOR_EACH_BB_FN (bb
, cfun
)
3337 gimple last
= last_stmt (bb
);
3338 if (last
&& is_gimple_resx (last
))
3340 dominance_invalidated
|= lower_resx (bb
, last
, mnt_map
);
3341 any_rewritten
= true;
3345 pointer_map_destroy (mnt_map
);
3347 if (dominance_invalidated
)
3349 free_dominance_info (CDI_DOMINATORS
);
3350 free_dominance_info (CDI_POST_DOMINATORS
);
3353 return any_rewritten
? TODO_update_ssa_only_virtuals
: 0;
3357 gate_lower_resx (void)
3359 return flag_exceptions
!= 0;
3364 const pass_data pass_data_lower_resx
=
3366 GIMPLE_PASS
, /* type */
3368 OPTGROUP_NONE
, /* optinfo_flags */
3369 true, /* has_gate */
3370 true, /* has_execute */
3371 TV_TREE_EH
, /* tv_id */
3372 PROP_gimple_lcf
, /* properties_required */
3373 0, /* properties_provided */
3374 0, /* properties_destroyed */
3375 0, /* todo_flags_start */
3376 TODO_verify_flow
, /* todo_flags_finish */
3379 class pass_lower_resx
: public gimple_opt_pass
3382 pass_lower_resx (gcc::context
*ctxt
)
3383 : gimple_opt_pass (pass_data_lower_resx
, ctxt
)
3386 /* opt_pass methods: */
3387 bool gate () { return gate_lower_resx (); }
3388 unsigned int execute () { return execute_lower_resx (); }
3390 }; // class pass_lower_resx
3395 make_pass_lower_resx (gcc::context
*ctxt
)
3397 return new pass_lower_resx (ctxt
);
3400 /* Try to optimize var = {v} {CLOBBER} stmts followed just by
3404 optimize_clobbers (basic_block bb
)
3406 gimple_stmt_iterator gsi
= gsi_last_bb (bb
);
3407 bool any_clobbers
= false;
3408 bool seen_stack_restore
= false;
3412 /* Only optimize anything if the bb contains at least one clobber,
3413 ends with resx (checked by caller), optionally contains some
3414 debug stmts or labels, or at most one __builtin_stack_restore
3415 call, and has an incoming EH edge. */
3416 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3418 gimple stmt
= gsi_stmt (gsi
);
3419 if (is_gimple_debug (stmt
))
3421 if (gimple_clobber_p (stmt
))
3423 any_clobbers
= true;
3426 if (!seen_stack_restore
3427 && gimple_call_builtin_p (stmt
, BUILT_IN_STACK_RESTORE
))
3429 seen_stack_restore
= true;
3432 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3438 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3439 if (e
->flags
& EDGE_EH
)
3443 gsi
= gsi_last_bb (bb
);
3444 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3446 gimple stmt
= gsi_stmt (gsi
);
3447 if (!gimple_clobber_p (stmt
))
3449 unlink_stmt_vdef (stmt
);
3450 gsi_remove (&gsi
, true);
3451 release_defs (stmt
);
3455 /* Try to sink var = {v} {CLOBBER} stmts followed just by
3456 internal throw to successor BB. */
3459 sink_clobbers (basic_block bb
)
3463 gimple_stmt_iterator gsi
, dgsi
;
3465 bool any_clobbers
= false;
3468 /* Only optimize if BB has a single EH successor and
3469 all predecessor edges are EH too. */
3470 if (!single_succ_p (bb
)
3471 || (single_succ_edge (bb
)->flags
& EDGE_EH
) == 0)
3474 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
3476 if ((e
->flags
& EDGE_EH
) == 0)
3480 /* And BB contains only CLOBBER stmts before the final
3482 gsi
= gsi_last_bb (bb
);
3483 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3485 gimple stmt
= gsi_stmt (gsi
);
3486 if (is_gimple_debug (stmt
))
3488 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3490 if (!gimple_clobber_p (stmt
))
3492 any_clobbers
= true;
3497 edge succe
= single_succ_edge (bb
);
3498 succbb
= succe
->dest
;
3500 /* See if there is a virtual PHI node to take an updated virtual
3503 tree vuse
= NULL_TREE
;
3504 for (gsi
= gsi_start_phis (succbb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3506 tree res
= gimple_phi_result (gsi_stmt (gsi
));
3507 if (virtual_operand_p (res
))
3509 vphi
= gsi_stmt (gsi
);
3515 dgsi
= gsi_after_labels (succbb
);
3516 gsi
= gsi_last_bb (bb
);
3517 for (gsi_prev (&gsi
); !gsi_end_p (gsi
); gsi_prev (&gsi
))
3519 gimple stmt
= gsi_stmt (gsi
);
3521 if (is_gimple_debug (stmt
))
3523 if (gimple_code (stmt
) == GIMPLE_LABEL
)
3525 lhs
= gimple_assign_lhs (stmt
);
3526 /* Unfortunately we don't have dominance info updated at this
3527 point, so checking if
3528 dominated_by_p (CDI_DOMINATORS, succbb,
3529 gimple_bb (SSA_NAME_DEF_STMT (TREE_OPERAND (lhs, 0)))
3530 would be too costly. Thus, avoid sinking any clobbers that
3531 refer to non-(D) SSA_NAMEs. */
3532 if (TREE_CODE (lhs
) == MEM_REF
3533 && TREE_CODE (TREE_OPERAND (lhs
, 0)) == SSA_NAME
3534 && !SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs
, 0)))
3536 unlink_stmt_vdef (stmt
);
3537 gsi_remove (&gsi
, true);
3538 release_defs (stmt
);
3542 /* As we do not change stmt order when sinking across a
3543 forwarder edge we can keep virtual operands in place. */
3544 gsi_remove (&gsi
, false);
3545 gsi_insert_before (&dgsi
, stmt
, GSI_NEW_STMT
);
3547 /* But adjust virtual operands if we sunk across a PHI node. */
3551 imm_use_iterator iter
;
3552 use_operand_p use_p
;
3553 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, vuse
)
3554 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
3555 SET_USE (use_p
, gimple_vdef (stmt
));
3556 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
))
3558 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (gimple_vdef (stmt
)) = 1;
3559 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse
) = 0;
3561 /* Adjust the incoming virtual operand. */
3562 SET_USE (PHI_ARG_DEF_PTR_FROM_EDGE (vphi
, succe
), gimple_vuse (stmt
));
3563 SET_USE (gimple_vuse_op (stmt
), vuse
);
3565 /* If there isn't a single predecessor but no virtual PHI node
3566 arrange for virtual operands to be renamed. */
3567 else if (gimple_vuse_op (stmt
) != NULL_USE_OPERAND_P
3568 && !single_pred_p (succbb
))
3570 /* In this case there will be no use of the VDEF of this stmt.
3571 ??? Unless this is a secondary opportunity and we have not
3572 removed unreachable blocks yet, so we cannot assert this.
3573 Which also means we will end up renaming too many times. */
3574 SET_USE (gimple_vuse_op (stmt
), gimple_vop (cfun
));
3575 mark_virtual_operands_for_renaming (cfun
);
3576 todo
|= TODO_update_ssa_only_virtuals
;
3583 /* At the end of inlining, we can lower EH_DISPATCH. Return true when
3584 we have found some duplicate labels and removed some edges. */
3587 lower_eh_dispatch (basic_block src
, gimple stmt
)
3589 gimple_stmt_iterator gsi
;
3594 bool redirected
= false;
3596 region_nr
= gimple_eh_dispatch_region (stmt
);
3597 r
= get_eh_region_from_number (region_nr
);
3599 gsi
= gsi_last_bb (src
);
3605 auto_vec
<tree
> labels
;
3606 tree default_label
= NULL
;
3610 struct pointer_set_t
*seen_values
= pointer_set_create ();
3612 /* Collect the labels for a switch. Zero the post_landing_pad
3613 field becase we'll no longer have anything keeping these labels
3614 in existence and the optimizer will be free to merge these
3616 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
3618 tree tp_node
, flt_node
, lab
= c
->label
;
3619 bool have_label
= false;
3622 tp_node
= c
->type_list
;
3623 flt_node
= c
->filter_list
;
3625 if (tp_node
== NULL
)
3627 default_label
= lab
;
3632 /* Filter out duplicate labels that arise when this handler
3633 is shadowed by an earlier one. When no labels are
3634 attached to the handler anymore, we remove
3635 the corresponding edge and then we delete unreachable
3636 blocks at the end of this pass. */
3637 if (! pointer_set_contains (seen_values
, TREE_VALUE (flt_node
)))
3639 tree t
= build_case_label (TREE_VALUE (flt_node
),
3641 labels
.safe_push (t
);
3642 pointer_set_insert (seen_values
, TREE_VALUE (flt_node
));
3646 tp_node
= TREE_CHAIN (tp_node
);
3647 flt_node
= TREE_CHAIN (flt_node
);
3652 remove_edge (find_edge (src
, label_to_block (lab
)));
3657 /* Clean up the edge flags. */
3658 FOR_EACH_EDGE (e
, ei
, src
->succs
)
3660 if (e
->flags
& EDGE_FALLTHRU
)
3662 /* If there was no catch-all, use the fallthru edge. */
3663 if (default_label
== NULL
)
3664 default_label
= gimple_block_label (e
->dest
);
3665 e
->flags
&= ~EDGE_FALLTHRU
;
3668 gcc_assert (default_label
!= NULL
);
3670 /* Don't generate a switch if there's only a default case.
3671 This is common in the form of try { A; } catch (...) { B; }. */
3672 if (!labels
.exists ())
3674 e
= single_succ_edge (src
);
3675 e
->flags
|= EDGE_FALLTHRU
;
3679 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3680 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3682 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)), NULL
);
3683 filter
= make_ssa_name (filter
, x
);
3684 gimple_call_set_lhs (x
, filter
);
3685 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3687 /* Turn the default label into a default case. */
3688 default_label
= build_case_label (NULL
, NULL
, default_label
);
3689 sort_case_labels (labels
);
3691 x
= gimple_build_switch (filter
, default_label
, labels
);
3692 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3694 pointer_set_destroy (seen_values
);
3698 case ERT_ALLOWED_EXCEPTIONS
:
3700 edge b_e
= BRANCH_EDGE (src
);
3701 edge f_e
= FALLTHRU_EDGE (src
);
3703 fn
= builtin_decl_implicit (BUILT_IN_EH_FILTER
);
3704 x
= gimple_build_call (fn
, 1, build_int_cst (integer_type_node
,
3706 filter
= create_tmp_var (TREE_TYPE (TREE_TYPE (fn
)), NULL
);
3707 filter
= make_ssa_name (filter
, x
);
3708 gimple_call_set_lhs (x
, filter
);
3709 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3711 r
->u
.allowed
.label
= NULL
;
3712 x
= gimple_build_cond (EQ_EXPR
, filter
,
3713 build_int_cst (TREE_TYPE (filter
),
3714 r
->u
.allowed
.filter
),
3715 NULL_TREE
, NULL_TREE
);
3716 gsi_insert_before (&gsi
, x
, GSI_SAME_STMT
);
3718 b_e
->flags
= b_e
->flags
| EDGE_TRUE_VALUE
;
3719 f_e
->flags
= (f_e
->flags
& ~EDGE_FALLTHRU
) | EDGE_FALSE_VALUE
;
3727 /* Replace the EH_DISPATCH with the SWITCH or COND generated above. */
3728 gsi_remove (&gsi
, true);
3733 execute_lower_eh_dispatch (void)
3737 bool redirected
= false;
3739 assign_filter_values ();
3741 FOR_EACH_BB_FN (bb
, cfun
)
3743 gimple last
= last_stmt (bb
);
3746 if (gimple_code (last
) == GIMPLE_EH_DISPATCH
)
3748 redirected
|= lower_eh_dispatch (bb
, last
);
3749 flags
|= TODO_update_ssa_only_virtuals
;
3751 else if (gimple_code (last
) == GIMPLE_RESX
)
3753 if (stmt_can_throw_external (last
))
3754 optimize_clobbers (bb
);
3756 flags
|= sink_clobbers (bb
);
3761 delete_unreachable_blocks ();
3766 gate_lower_eh_dispatch (void)
3768 return cfun
->eh
->region_tree
!= NULL
;
3773 const pass_data pass_data_lower_eh_dispatch
=
3775 GIMPLE_PASS
, /* type */
3776 "ehdisp", /* name */
3777 OPTGROUP_NONE
, /* optinfo_flags */
3778 true, /* has_gate */
3779 true, /* has_execute */
3780 TV_TREE_EH
, /* tv_id */
3781 PROP_gimple_lcf
, /* properties_required */
3782 0, /* properties_provided */
3783 0, /* properties_destroyed */
3784 0, /* todo_flags_start */
3785 TODO_verify_flow
, /* todo_flags_finish */
3788 class pass_lower_eh_dispatch
: public gimple_opt_pass
3791 pass_lower_eh_dispatch (gcc::context
*ctxt
)
3792 : gimple_opt_pass (pass_data_lower_eh_dispatch
, ctxt
)
3795 /* opt_pass methods: */
3796 bool gate () { return gate_lower_eh_dispatch (); }
3797 unsigned int execute () { return execute_lower_eh_dispatch (); }
3799 }; // class pass_lower_eh_dispatch
3804 make_pass_lower_eh_dispatch (gcc::context
*ctxt
)
3806 return new pass_lower_eh_dispatch (ctxt
);
3809 /* Walk statements, see what regions and, optionally, landing pads
3810 are really referenced.
3812 Returns in R_REACHABLEP an sbitmap with bits set for reachable regions,
3813 and in LP_REACHABLE an sbitmap with bits set for reachable landing pads.
3815 Passing NULL for LP_REACHABLE is valid, in this case only reachable
3818 The caller is responsible for freeing the returned sbitmaps. */
3821 mark_reachable_handlers (sbitmap
*r_reachablep
, sbitmap
*lp_reachablep
)
3823 sbitmap r_reachable
, lp_reachable
;
3825 bool mark_landing_pads
= (lp_reachablep
!= NULL
);
3826 gcc_checking_assert (r_reachablep
!= NULL
);
3828 r_reachable
= sbitmap_alloc (cfun
->eh
->region_array
->length ());
3829 bitmap_clear (r_reachable
);
3830 *r_reachablep
= r_reachable
;
3832 if (mark_landing_pads
)
3834 lp_reachable
= sbitmap_alloc (cfun
->eh
->lp_array
->length ());
3835 bitmap_clear (lp_reachable
);
3836 *lp_reachablep
= lp_reachable
;
3839 lp_reachable
= NULL
;
3841 FOR_EACH_BB_FN (bb
, cfun
)
3843 gimple_stmt_iterator gsi
;
3845 for (gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
); gsi_next (&gsi
))
3847 gimple stmt
= gsi_stmt (gsi
);
3849 if (mark_landing_pads
)
3851 int lp_nr
= lookup_stmt_eh_lp (stmt
);
3853 /* Negative LP numbers are MUST_NOT_THROW regions which
3854 are not considered BB enders. */
3856 bitmap_set_bit (r_reachable
, -lp_nr
);
3858 /* Positive LP numbers are real landing pads, and BB enders. */
3861 gcc_assert (gsi_one_before_end_p (gsi
));
3862 eh_region region
= get_eh_region_from_lp_number (lp_nr
);
3863 bitmap_set_bit (r_reachable
, region
->index
);
3864 bitmap_set_bit (lp_reachable
, lp_nr
);
3868 /* Avoid removing regions referenced from RESX/EH_DISPATCH. */
3869 switch (gimple_code (stmt
))
3872 bitmap_set_bit (r_reachable
, gimple_resx_region (stmt
));
3874 case GIMPLE_EH_DISPATCH
:
3875 bitmap_set_bit (r_reachable
, gimple_eh_dispatch_region (stmt
));
3884 /* Remove unreachable handlers and unreachable landing pads. */
3887 remove_unreachable_handlers (void)
3889 sbitmap r_reachable
, lp_reachable
;
3894 mark_reachable_handlers (&r_reachable
, &lp_reachable
);
3898 fprintf (dump_file
, "Before removal of unreachable regions:\n");
3899 dump_eh_tree (dump_file
, cfun
);
3900 fprintf (dump_file
, "Reachable regions: ");
3901 dump_bitmap_file (dump_file
, r_reachable
);
3902 fprintf (dump_file
, "Reachable landing pads: ");
3903 dump_bitmap_file (dump_file
, lp_reachable
);
3908 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3909 if (region
&& !bitmap_bit_p (r_reachable
, region
->index
))
3911 "Removing unreachable region %d\n",
3915 remove_unreachable_eh_regions (r_reachable
);
3917 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3918 if (lp
&& !bitmap_bit_p (lp_reachable
, lp
->index
))
3922 "Removing unreachable landing pad %d\n",
3924 remove_eh_landing_pad (lp
);
3929 fprintf (dump_file
, "\n\nAfter removal of unreachable regions:\n");
3930 dump_eh_tree (dump_file
, cfun
);
3931 fprintf (dump_file
, "\n\n");
3934 sbitmap_free (r_reachable
);
3935 sbitmap_free (lp_reachable
);
3937 #ifdef ENABLE_CHECKING
3938 verify_eh_tree (cfun
);
3942 /* Remove unreachable handlers if any landing pads have been removed after
3943 last ehcleanup pass (due to gimple_purge_dead_eh_edges). */
3946 maybe_remove_unreachable_handlers (void)
3951 if (cfun
->eh
== NULL
)
3954 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->lp_array
, i
, lp
)
3955 if (lp
&& lp
->post_landing_pad
)
3957 if (label_to_block (lp
->post_landing_pad
) == NULL
)
3959 remove_unreachable_handlers ();
3965 /* Remove regions that do not have landing pads. This assumes
3966 that remove_unreachable_handlers has already been run, and
3967 that we've just manipulated the landing pads since then.
3969 Preserve regions with landing pads and regions that prevent
3970 exceptions from propagating further, even if these regions
3971 are not reachable. */
3974 remove_unreachable_handlers_no_lp (void)
3977 sbitmap r_reachable
;
3980 mark_reachable_handlers (&r_reachable
, /*lp_reachablep=*/NULL
);
3982 FOR_EACH_VEC_SAFE_ELT (cfun
->eh
->region_array
, i
, region
)
3987 if (region
->landing_pads
!= NULL
3988 || region
->type
== ERT_MUST_NOT_THROW
)
3989 bitmap_set_bit (r_reachable
, region
->index
);
3992 && !bitmap_bit_p (r_reachable
, region
->index
))
3994 "Removing unreachable region %d\n",
3998 remove_unreachable_eh_regions (r_reachable
);
4000 sbitmap_free (r_reachable
);
4003 /* Undo critical edge splitting on an EH landing pad. Earlier, we
4004 optimisticaly split all sorts of edges, including EH edges. The
4005 optimization passes in between may not have needed them; if not,
4006 we should undo the split.
4008 Recognize this case by having one EH edge incoming to the BB and
4009 one normal edge outgoing; BB should be empty apart from the
4010 post_landing_pad label.
4012 Note that this is slightly different from the empty handler case
4013 handled by cleanup_empty_eh, in that the actual handler may yet
4014 have actual code but the landing pad has been separated from the
4015 handler. As such, cleanup_empty_eh relies on this transformation
4016 having been done first. */
4019 unsplit_eh (eh_landing_pad lp
)
4021 basic_block bb
= label_to_block (lp
->post_landing_pad
);
4022 gimple_stmt_iterator gsi
;
4025 /* Quickly check the edge counts on BB for singularity. */
4026 if (!single_pred_p (bb
) || !single_succ_p (bb
))
4028 e_in
= single_pred_edge (bb
);
4029 e_out
= single_succ_edge (bb
);
4031 /* Input edge must be EH and output edge must be normal. */
4032 if ((e_in
->flags
& EDGE_EH
) == 0 || (e_out
->flags
& EDGE_EH
) != 0)
4035 /* The block must be empty except for the labels and debug insns. */
4036 gsi
= gsi_after_labels (bb
);
4037 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4038 gsi_next_nondebug (&gsi
);
4039 if (!gsi_end_p (gsi
))
4042 /* The destination block must not already have a landing pad
4043 for a different region. */
4044 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4046 gimple stmt
= gsi_stmt (gsi
);
4050 if (gimple_code (stmt
) != GIMPLE_LABEL
)
4052 lab
= gimple_label_label (stmt
);
4053 lp_nr
= EH_LANDING_PAD_NR (lab
);
4054 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4058 /* The new destination block must not already be a destination of
4059 the source block, lest we merge fallthru and eh edges and get
4060 all sorts of confused. */
4061 if (find_edge (e_in
->src
, e_out
->dest
))
4064 /* ??? We can get degenerate phis due to cfg cleanups. I would have
4065 thought this should have been cleaned up by a phicprop pass, but
4066 that doesn't appear to handle virtuals. Propagate by hand. */
4067 if (!gimple_seq_empty_p (phi_nodes (bb
)))
4069 for (gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
); )
4071 gimple use_stmt
, phi
= gsi_stmt (gsi
);
4072 tree lhs
= gimple_phi_result (phi
);
4073 tree rhs
= gimple_phi_arg_def (phi
, 0);
4074 use_operand_p use_p
;
4075 imm_use_iterator iter
;
4077 FOR_EACH_IMM_USE_STMT (use_stmt
, iter
, lhs
)
4079 FOR_EACH_IMM_USE_ON_STMT (use_p
, iter
)
4080 SET_USE (use_p
, rhs
);
4083 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs
))
4084 SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs
) = 1;
4086 remove_phi_node (&gsi
, true);
4090 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4091 fprintf (dump_file
, "Unsplit EH landing pad %d to block %i.\n",
4092 lp
->index
, e_out
->dest
->index
);
4094 /* Redirect the edge. Since redirect_eh_edge_1 expects to be moving
4095 a successor edge, humor it. But do the real CFG change with the
4096 predecessor of E_OUT in order to preserve the ordering of arguments
4097 to the PHI nodes in E_OUT->DEST. */
4098 redirect_eh_edge_1 (e_in
, e_out
->dest
, false);
4099 redirect_edge_pred (e_out
, e_in
->src
);
4100 e_out
->flags
= e_in
->flags
;
4101 e_out
->probability
= e_in
->probability
;
4102 e_out
->count
= e_in
->count
;
4108 /* Examine each landing pad block and see if it matches unsplit_eh. */
4111 unsplit_all_eh (void)
4113 bool changed
= false;
4117 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4119 changed
|= unsplit_eh (lp
);
4124 /* A subroutine of cleanup_empty_eh. Redirect all EH edges incoming
4125 to OLD_BB to NEW_BB; return true on success, false on failure.
4127 OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any
4128 PHI variables from OLD_BB we can pick them up from OLD_BB_OUT.
4129 Virtual PHIs may be deleted and marked for renaming. */
4132 cleanup_empty_eh_merge_phis (basic_block new_bb
, basic_block old_bb
,
4133 edge old_bb_out
, bool change_region
)
4135 gimple_stmt_iterator ngsi
, ogsi
;
4138 bitmap ophi_handled
;
4140 /* The destination block must not be a regular successor for any
4141 of the preds of the landing pad. Thus, avoid turning
4151 which CFG verification would choke on. See PR45172 and PR51089. */
4152 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4153 if (find_edge (e
->src
, new_bb
))
4156 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4157 redirect_edge_var_map_clear (e
);
4159 ophi_handled
= BITMAP_ALLOC (NULL
);
4161 /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
4162 for the edges we're going to move. */
4163 for (ngsi
= gsi_start_phis (new_bb
); !gsi_end_p (ngsi
); gsi_next (&ngsi
))
4165 gimple ophi
, nphi
= gsi_stmt (ngsi
);
4168 nresult
= gimple_phi_result (nphi
);
4169 nop
= gimple_phi_arg_def (nphi
, old_bb_out
->dest_idx
);
4171 /* Find the corresponding PHI in OLD_BB so we can forward-propagate
4172 the source ssa_name. */
4174 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4176 ophi
= gsi_stmt (ogsi
);
4177 if (gimple_phi_result (ophi
) == nop
)
4182 /* If we did find the corresponding PHI, copy those inputs. */
4185 /* If NOP is used somewhere else beyond phis in new_bb, give up. */
4186 if (!has_single_use (nop
))
4188 imm_use_iterator imm_iter
;
4189 use_operand_p use_p
;
4191 FOR_EACH_IMM_USE_FAST (use_p
, imm_iter
, nop
)
4193 if (!gimple_debug_bind_p (USE_STMT (use_p
))
4194 && (gimple_code (USE_STMT (use_p
)) != GIMPLE_PHI
4195 || gimple_bb (USE_STMT (use_p
)) != new_bb
))
4199 bitmap_set_bit (ophi_handled
, SSA_NAME_VERSION (nop
));
4200 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4205 if ((e
->flags
& EDGE_EH
) == 0)
4207 oop
= gimple_phi_arg_def (ophi
, e
->dest_idx
);
4208 oloc
= gimple_phi_arg_location (ophi
, e
->dest_idx
);
4209 redirect_edge_var_map_add (e
, nresult
, oop
, oloc
);
4212 /* If we didn't find the PHI, if it's a real variable or a VOP, we know
4213 from the fact that OLD_BB is tree_empty_eh_handler_p that the
4214 variable is unchanged from input to the block and we can simply
4215 re-use the input to NEW_BB from the OLD_BB_OUT edge. */
4219 = gimple_phi_arg_location (nphi
, old_bb_out
->dest_idx
);
4220 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4221 redirect_edge_var_map_add (e
, nresult
, nop
, nloc
);
4225 /* Second, verify that all PHIs from OLD_BB have been handled. If not,
4226 we don't know what values from the other edges into NEW_BB to use. */
4227 for (ogsi
= gsi_start_phis (old_bb
); !gsi_end_p (ogsi
); gsi_next (&ogsi
))
4229 gimple ophi
= gsi_stmt (ogsi
);
4230 tree oresult
= gimple_phi_result (ophi
);
4231 if (!bitmap_bit_p (ophi_handled
, SSA_NAME_VERSION (oresult
)))
4235 /* Finally, move the edges and update the PHIs. */
4236 for (ei
= ei_start (old_bb
->preds
); (e
= ei_safe_edge (ei
)); )
4237 if (e
->flags
& EDGE_EH
)
4239 /* ??? CFG manipluation routines do not try to update loop
4240 form on edge redirection. Do so manually here for now. */
4241 /* If we redirect a loop entry or latch edge that will either create
4242 a multiple entry loop or rotate the loop. If the loops merge
4243 we may have created a loop with multiple latches.
4244 All of this isn't easily fixed thus cancel the affected loop
4245 and mark the other loop as possibly having multiple latches. */
4247 && e
->dest
== e
->dest
->loop_father
->header
)
4249 mark_loop_for_removal (e
->dest
->loop_father
);
4250 new_bb
->loop_father
->latch
= NULL
;
4251 loops_state_set (LOOPS_MAY_HAVE_MULTIPLE_LATCHES
);
4253 redirect_eh_edge_1 (e
, new_bb
, change_region
);
4254 redirect_edge_succ (e
, new_bb
);
4255 flush_pending_stmts (e
);
4260 BITMAP_FREE (ophi_handled
);
4264 FOR_EACH_EDGE (e
, ei
, old_bb
->preds
)
4265 redirect_edge_var_map_clear (e
);
4266 BITMAP_FREE (ophi_handled
);
4270 /* A subroutine of cleanup_empty_eh. Move a landing pad LP from its
4271 old region to NEW_REGION at BB. */
4274 cleanup_empty_eh_move_lp (basic_block bb
, edge e_out
,
4275 eh_landing_pad lp
, eh_region new_region
)
4277 gimple_stmt_iterator gsi
;
4280 for (pp
= &lp
->region
->landing_pads
; *pp
!= lp
; pp
= &(*pp
)->next_lp
)
4284 lp
->region
= new_region
;
4285 lp
->next_lp
= new_region
->landing_pads
;
4286 new_region
->landing_pads
= lp
;
4288 /* Delete the RESX that was matched within the empty handler block. */
4289 gsi
= gsi_last_bb (bb
);
4290 unlink_stmt_vdef (gsi_stmt (gsi
));
4291 gsi_remove (&gsi
, true);
4293 /* Clean up E_OUT for the fallthru. */
4294 e_out
->flags
= (e_out
->flags
& ~EDGE_EH
) | EDGE_FALLTHRU
;
4295 e_out
->probability
= REG_BR_PROB_BASE
;
4298 /* A subroutine of cleanup_empty_eh. Handle more complex cases of
4299 unsplitting than unsplit_eh was prepared to handle, e.g. when
4300 multiple incoming edges and phis are involved. */
4303 cleanup_empty_eh_unsplit (basic_block bb
, edge e_out
, eh_landing_pad lp
)
4305 gimple_stmt_iterator gsi
;
4308 /* We really ought not have totally lost everything following
4309 a landing pad label. Given that BB is empty, there had better
4311 gcc_assert (e_out
!= NULL
);
4313 /* The destination block must not already have a landing pad
4314 for a different region. */
4316 for (gsi
= gsi_start_bb (e_out
->dest
); !gsi_end_p (gsi
); gsi_next (&gsi
))
4318 gimple stmt
= gsi_stmt (gsi
);
4321 if (gimple_code (stmt
) != GIMPLE_LABEL
)
4323 lab
= gimple_label_label (stmt
);
4324 lp_nr
= EH_LANDING_PAD_NR (lab
);
4325 if (lp_nr
&& get_eh_region_from_lp_number (lp_nr
) != lp
->region
)
4329 /* Attempt to move the PHIs into the successor block. */
4330 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, false))
4332 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4334 "Unsplit EH landing pad %d to block %i "
4335 "(via cleanup_empty_eh).\n",
4336 lp
->index
, e_out
->dest
->index
);
4343 /* Return true if edge E_FIRST is part of an empty infinite loop
4344 or leads to such a loop through a series of single successor
4348 infinite_empty_loop_p (edge e_first
)
4350 bool inf_loop
= false;
4353 if (e_first
->dest
== e_first
->src
)
4356 e_first
->src
->aux
= (void *) 1;
4357 for (e
= e_first
; single_succ_p (e
->dest
); e
= single_succ_edge (e
->dest
))
4359 gimple_stmt_iterator gsi
;
4365 e
->dest
->aux
= (void *) 1;
4366 gsi
= gsi_after_labels (e
->dest
);
4367 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4368 gsi_next_nondebug (&gsi
);
4369 if (!gsi_end_p (gsi
))
4372 e_first
->src
->aux
= NULL
;
4373 for (e
= e_first
; e
->dest
->aux
; e
= single_succ_edge (e
->dest
))
4374 e
->dest
->aux
= NULL
;
4379 /* Examine the block associated with LP to determine if it's an empty
4380 handler for its EH region. If so, attempt to redirect EH edges to
4381 an outer region. Return true the CFG was updated in any way. This
4382 is similar to jump forwarding, just across EH edges. */
4385 cleanup_empty_eh (eh_landing_pad lp
)
4387 basic_block bb
= label_to_block (lp
->post_landing_pad
);
4388 gimple_stmt_iterator gsi
;
4390 eh_region new_region
;
4393 bool has_non_eh_pred
;
4397 /* There can be zero or one edges out of BB. This is the quickest test. */
4398 switch (EDGE_COUNT (bb
->succs
))
4404 e_out
= single_succ_edge (bb
);
4410 resx
= last_stmt (bb
);
4411 if (resx
&& is_gimple_resx (resx
))
4413 if (stmt_can_throw_external (resx
))
4414 optimize_clobbers (bb
);
4415 else if (sink_clobbers (bb
))
4419 gsi
= gsi_after_labels (bb
);
4421 /* Make sure to skip debug statements. */
4422 if (!gsi_end_p (gsi
) && is_gimple_debug (gsi_stmt (gsi
)))
4423 gsi_next_nondebug (&gsi
);
4425 /* If the block is totally empty, look for more unsplitting cases. */
4426 if (gsi_end_p (gsi
))
4428 /* For the degenerate case of an infinite loop bail out.
4429 If bb has no successors and is totally empty, which can happen e.g.
4430 because of incorrect noreturn attribute, bail out too. */
4432 || infinite_empty_loop_p (e_out
))
4435 return ret
| cleanup_empty_eh_unsplit (bb
, e_out
, lp
);
4438 /* The block should consist only of a single RESX statement, modulo a
4439 preceding call to __builtin_stack_restore if there is no outgoing
4440 edge, since the call can be eliminated in this case. */
4441 resx
= gsi_stmt (gsi
);
4442 if (!e_out
&& gimple_call_builtin_p (resx
, BUILT_IN_STACK_RESTORE
))
4445 resx
= gsi_stmt (gsi
);
4447 if (!is_gimple_resx (resx
))
4449 gcc_assert (gsi_one_before_end_p (gsi
));
4451 /* Determine if there are non-EH edges, or resx edges into the handler. */
4452 has_non_eh_pred
= false;
4453 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
4454 if (!(e
->flags
& EDGE_EH
))
4455 has_non_eh_pred
= true;
4457 /* Find the handler that's outer of the empty handler by looking at
4458 where the RESX instruction was vectored. */
4459 new_lp_nr
= lookup_stmt_eh_lp (resx
);
4460 new_region
= get_eh_region_from_lp_number (new_lp_nr
);
4462 /* If there's no destination region within the current function,
4463 redirection is trivial via removing the throwing statements from
4464 the EH region, removing the EH edges, and allowing the block
4465 to go unreachable. */
4466 if (new_region
== NULL
)
4468 gcc_assert (e_out
== NULL
);
4469 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4470 if (e
->flags
& EDGE_EH
)
4472 gimple stmt
= last_stmt (e
->src
);
4473 remove_stmt_from_eh_lp (stmt
);
4481 /* If the destination region is a MUST_NOT_THROW, allow the runtime
4482 to handle the abort and allow the blocks to go unreachable. */
4483 if (new_region
->type
== ERT_MUST_NOT_THROW
)
4485 for (ei
= ei_start (bb
->preds
); (e
= ei_safe_edge (ei
)); )
4486 if (e
->flags
& EDGE_EH
)
4488 gimple stmt
= last_stmt (e
->src
);
4489 remove_stmt_from_eh_lp (stmt
);
4490 add_stmt_to_eh_lp (stmt
, new_lp_nr
);
4498 /* Try to redirect the EH edges and merge the PHIs into the destination
4499 landing pad block. If the merge succeeds, we'll already have redirected
4500 all the EH edges. The handler itself will go unreachable if there were
4502 if (cleanup_empty_eh_merge_phis (e_out
->dest
, bb
, e_out
, true))
4505 /* Finally, if all input edges are EH edges, then we can (potentially)
4506 reduce the number of transfers from the runtime by moving the landing
4507 pad from the original region to the new region. This is a win when
4508 we remove the last CLEANUP region along a particular exception
4509 propagation path. Since nothing changes except for the region with
4510 which the landing pad is associated, the PHI nodes do not need to be
4512 if (!has_non_eh_pred
)
4514 cleanup_empty_eh_move_lp (bb
, e_out
, lp
, new_region
);
4515 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4516 fprintf (dump_file
, "Empty EH handler %i moved to EH region %i.\n",
4517 lp
->index
, new_region
->index
);
4519 /* ??? The CFG didn't change, but we may have rendered the
4520 old EH region unreachable. Trigger a cleanup there. */
4527 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
4528 fprintf (dump_file
, "Empty EH handler %i removed.\n", lp
->index
);
4529 remove_eh_landing_pad (lp
);
4533 /* Do a post-order traversal of the EH region tree. Examine each
4534 post_landing_pad block and see if we can eliminate it as empty. */
4537 cleanup_all_empty_eh (void)
4539 bool changed
= false;
4543 for (i
= 1; vec_safe_iterate (cfun
->eh
->lp_array
, i
, &lp
); ++i
)
4545 changed
|= cleanup_empty_eh (lp
);
4550 /* Perform cleanups and lowering of exception handling
4551 1) cleanups regions with handlers doing nothing are optimized out
4552 2) MUST_NOT_THROW regions that became dead because of 1) are optimized out
4553 3) Info about regions that are containing instructions, and regions
4554 reachable via local EH edges is collected
4555 4) Eh tree is pruned for regions no longer necessary.
4557 TODO: Push MUST_NOT_THROW regions to the root of the EH tree.
4558 Unify those that have the same failure decl and locus.
4562 execute_cleanup_eh_1 (void)
4564 /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
4565 looking up unreachable landing pads. */
4566 remove_unreachable_handlers ();
4568 /* Watch out for the region tree vanishing due to all unreachable. */
4569 if (cfun
->eh
->region_tree
)
4571 bool changed
= false;
4574 changed
|= unsplit_all_eh ();
4575 changed
|= cleanup_all_empty_eh ();
4579 free_dominance_info (CDI_DOMINATORS
);
4580 free_dominance_info (CDI_POST_DOMINATORS
);
4582 /* We delayed all basic block deletion, as we may have performed
4583 cleanups on EH edges while non-EH edges were still present. */
4584 delete_unreachable_blocks ();
4586 /* We manipulated the landing pads. Remove any region that no
4587 longer has a landing pad. */
4588 remove_unreachable_handlers_no_lp ();
4590 return TODO_cleanup_cfg
| TODO_update_ssa_only_virtuals
;
4598 execute_cleanup_eh (void)
4600 int ret
= execute_cleanup_eh_1 ();
4602 /* If the function no longer needs an EH personality routine
4603 clear it. This exposes cross-language inlining opportunities
4604 and avoids references to a never defined personality routine. */
4605 if (DECL_FUNCTION_PERSONALITY (current_function_decl
)
4606 && function_needs_eh_personality (cfun
) != eh_personality_lang
)
4607 DECL_FUNCTION_PERSONALITY (current_function_decl
) = NULL_TREE
;
4613 gate_cleanup_eh (void)
4615 return cfun
->eh
!= NULL
&& cfun
->eh
->region_tree
!= NULL
;
4620 const pass_data pass_data_cleanup_eh
=
4622 GIMPLE_PASS
, /* type */
4623 "ehcleanup", /* name */
4624 OPTGROUP_NONE
, /* optinfo_flags */
4625 true, /* has_gate */
4626 true, /* has_execute */
4627 TV_TREE_EH
, /* tv_id */
4628 PROP_gimple_lcf
, /* properties_required */
4629 0, /* properties_provided */
4630 0, /* properties_destroyed */
4631 0, /* todo_flags_start */
4632 TODO_verify_ssa
, /* todo_flags_finish */
4635 class pass_cleanup_eh
: public gimple_opt_pass
4638 pass_cleanup_eh (gcc::context
*ctxt
)
4639 : gimple_opt_pass (pass_data_cleanup_eh
, ctxt
)
4642 /* opt_pass methods: */
4643 opt_pass
* clone () { return new pass_cleanup_eh (m_ctxt
); }
4644 bool gate () { return gate_cleanup_eh (); }
4645 unsigned int execute () { return execute_cleanup_eh (); }
4647 }; // class pass_cleanup_eh
4652 make_pass_cleanup_eh (gcc::context
*ctxt
)
4654 return new pass_cleanup_eh (ctxt
);
4657 /* Verify that BB containing STMT as the last statement, has precisely the
4658 edge that make_eh_edges would create. */
4661 verify_eh_edges (gimple stmt
)
4663 basic_block bb
= gimple_bb (stmt
);
4664 eh_landing_pad lp
= NULL
;
4669 lp_nr
= lookup_stmt_eh_lp (stmt
);
4671 lp
= get_eh_landing_pad_from_number (lp_nr
);
4674 FOR_EACH_EDGE (e
, ei
, bb
->succs
)
4676 if (e
->flags
& EDGE_EH
)
4680 error ("BB %i has multiple EH edges", bb
->index
);
4692 error ("BB %i can not throw but has an EH edge", bb
->index
);
4698 if (!stmt_could_throw_p (stmt
))
4700 error ("BB %i last statement has incorrectly set lp", bb
->index
);
4704 if (eh_edge
== NULL
)
4706 error ("BB %i is missing an EH edge", bb
->index
);
4710 if (eh_edge
->dest
!= label_to_block (lp
->post_landing_pad
))
4712 error ("Incorrect EH edge %i->%i", bb
->index
, eh_edge
->dest
->index
);
4719 /* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */
4722 verify_eh_dispatch_edge (gimple stmt
)
4726 basic_block src
, dst
;
4727 bool want_fallthru
= true;
4731 r
= get_eh_region_from_number (gimple_eh_dispatch_region (stmt
));
4732 src
= gimple_bb (stmt
);
4734 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4735 gcc_assert (e
->aux
== NULL
);
4740 for (c
= r
->u
.eh_try
.first_catch
; c
; c
= c
->next_catch
)
4742 dst
= label_to_block (c
->label
);
4743 e
= find_edge (src
, dst
);
4746 error ("BB %i is missing an edge", src
->index
);
4751 /* A catch-all handler doesn't have a fallthru. */
4752 if (c
->type_list
== NULL
)
4754 want_fallthru
= false;
4760 case ERT_ALLOWED_EXCEPTIONS
:
4761 dst
= label_to_block (r
->u
.allowed
.label
);
4762 e
= find_edge (src
, dst
);
4765 error ("BB %i is missing an edge", src
->index
);
4776 FOR_EACH_EDGE (e
, ei
, src
->succs
)
4778 if (e
->flags
& EDGE_FALLTHRU
)
4780 if (fall_edge
!= NULL
)
4782 error ("BB %i too many fallthru edges", src
->index
);
4791 error ("BB %i has incorrect edge", src
->index
);
4795 if ((fall_edge
!= NULL
) ^ want_fallthru
)
4797 error ("BB %i has incorrect fallthru edge", src
->index
);