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4ee9c684 | 1 | /* Exception handling semantics and decomposition for trees. |
a9309f85 | 2 | Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
cfaf579d | 3 | Free Software Foundation, Inc. |
4ee9c684 | 4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
8c4c00c1 | 9 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 10 | any later version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
4ee9c684 | 26 | #include "flags.h" |
27 | #include "function.h" | |
28 | #include "except.h" | |
778f5bdd | 29 | #include "pointer-set.h" |
4ee9c684 | 30 | #include "tree-flow.h" |
31 | #include "tree-dump.h" | |
32 | #include "tree-inline.h" | |
33 | #include "tree-iterator.h" | |
34 | #include "tree-pass.h" | |
35 | #include "timevar.h" | |
36 | #include "langhooks.h" | |
37 | #include "ggc.h" | |
0b205f4c | 38 | #include "diagnostic-core.h" |
75a70cf9 | 39 | #include "gimple.h" |
e38def9c | 40 | #include "target.h" |
75a70cf9 | 41 | |
42 | /* In some instances a tree and a gimple need to be stored in a same table, | |
43 | i.e. in hash tables. This is a structure to do this. */ | |
44 | typedef union {tree *tp; tree t; gimple g;} treemple; | |
4ee9c684 | 45 | |
873f1e89 | 46 | /* Nonzero if we are using EH to handle cleanups. */ |
47 | static int using_eh_for_cleanups_p = 0; | |
48 | ||
49 | void | |
50 | using_eh_for_cleanups (void) | |
51 | { | |
52 | using_eh_for_cleanups_p = 1; | |
53 | } | |
75a70cf9 | 54 | |
4ee9c684 | 55 | /* Misc functions used in this file. */ |
56 | ||
57 | /* Compare and hash for any structure which begins with a canonical | |
06b27565 | 58 | pointer. Assumes all pointers are interchangeable, which is sort |
4ee9c684 | 59 | of already assumed by gcc elsewhere IIRC. */ |
60 | ||
61 | static int | |
62 | struct_ptr_eq (const void *a, const void *b) | |
63 | { | |
680a19b9 | 64 | const void * const * x = (const void * const *) a; |
65 | const void * const * y = (const void * const *) b; | |
4ee9c684 | 66 | return *x == *y; |
67 | } | |
68 | ||
69 | static hashval_t | |
70 | struct_ptr_hash (const void *a) | |
71 | { | |
680a19b9 | 72 | const void * const * x = (const void * const *) a; |
4ee9c684 | 73 | return (size_t)*x >> 4; |
74 | } | |
75 | ||
75a70cf9 | 76 | |
e38def9c | 77 | /* Remember and lookup EH landing pad data for arbitrary statements. |
4ee9c684 | 78 | Really this means any statement that could_throw_p. We could |
79 | stuff this information into the stmt_ann data structure, but: | |
80 | ||
81 | (1) We absolutely rely on this information being kept until | |
82 | we get to rtl. Once we're done with lowering here, if we lose | |
83 | the information there's no way to recover it! | |
84 | ||
ac13e8d9 | 85 | (2) There are many more statements that *cannot* throw as |
4ee9c684 | 86 | compared to those that can. We should be saving some amount |
87 | of space by only allocating memory for those that can throw. */ | |
88 | ||
e38def9c | 89 | /* Add statement T in function IFUN to landing pad NUM. */ |
75a70cf9 | 90 | |
4ee9c684 | 91 | void |
e38def9c | 92 | add_stmt_to_eh_lp_fn (struct function *ifun, gimple t, int num) |
4ee9c684 | 93 | { |
94 | struct throw_stmt_node *n; | |
95 | void **slot; | |
96 | ||
e38def9c | 97 | gcc_assert (num != 0); |
4ee9c684 | 98 | |
ba72912a | 99 | n = ggc_alloc_throw_stmt_node (); |
4ee9c684 | 100 | n->stmt = t; |
e38def9c | 101 | n->lp_nr = num; |
4ee9c684 | 102 | |
0de999f1 | 103 | if (!get_eh_throw_stmt_table (ifun)) |
104 | set_eh_throw_stmt_table (ifun, htab_create_ggc (31, struct_ptr_hash, | |
105 | struct_ptr_eq, | |
106 | ggc_free)); | |
107 | ||
b3f1469f | 108 | slot = htab_find_slot (get_eh_throw_stmt_table (ifun), n, INSERT); |
8c0963c4 | 109 | gcc_assert (!*slot); |
4ee9c684 | 110 | *slot = n; |
111 | } | |
35c15734 | 112 | |
e38def9c | 113 | /* Add statement T in the current function (cfun) to EH landing pad NUM. */ |
75a70cf9 | 114 | |
b3f1469f | 115 | void |
e38def9c | 116 | add_stmt_to_eh_lp (gimple t, int num) |
b3f1469f | 117 | { |
e38def9c | 118 | add_stmt_to_eh_lp_fn (cfun, t, num); |
119 | } | |
120 | ||
121 | /* Add statement T to the single EH landing pad in REGION. */ | |
122 | ||
123 | static void | |
124 | record_stmt_eh_region (eh_region region, gimple t) | |
125 | { | |
126 | if (region == NULL) | |
127 | return; | |
128 | if (region->type == ERT_MUST_NOT_THROW) | |
129 | add_stmt_to_eh_lp_fn (cfun, t, -region->index); | |
130 | else | |
131 | { | |
132 | eh_landing_pad lp = region->landing_pads; | |
133 | if (lp == NULL) | |
134 | lp = gen_eh_landing_pad (region); | |
135 | else | |
136 | gcc_assert (lp->next_lp == NULL); | |
137 | add_stmt_to_eh_lp_fn (cfun, t, lp->index); | |
138 | } | |
b3f1469f | 139 | } |
140 | ||
75a70cf9 | 141 | |
e38def9c | 142 | /* Remove statement T in function IFUN from its EH landing pad. */ |
75a70cf9 | 143 | |
35c15734 | 144 | bool |
e38def9c | 145 | remove_stmt_from_eh_lp_fn (struct function *ifun, gimple t) |
35c15734 | 146 | { |
147 | struct throw_stmt_node dummy; | |
148 | void **slot; | |
149 | ||
b3f1469f | 150 | if (!get_eh_throw_stmt_table (ifun)) |
35c15734 | 151 | return false; |
152 | ||
153 | dummy.stmt = t; | |
b3f1469f | 154 | slot = htab_find_slot (get_eh_throw_stmt_table (ifun), &dummy, |
155 | NO_INSERT); | |
35c15734 | 156 | if (slot) |
157 | { | |
b3f1469f | 158 | htab_clear_slot (get_eh_throw_stmt_table (ifun), slot); |
35c15734 | 159 | return true; |
160 | } | |
161 | else | |
162 | return false; | |
163 | } | |
164 | ||
75a70cf9 | 165 | |
e38def9c | 166 | /* Remove statement T in the current function (cfun) from its |
167 | EH landing pad. */ | |
75a70cf9 | 168 | |
b3f1469f | 169 | bool |
e38def9c | 170 | remove_stmt_from_eh_lp (gimple t) |
b3f1469f | 171 | { |
e38def9c | 172 | return remove_stmt_from_eh_lp_fn (cfun, t); |
b3f1469f | 173 | } |
174 | ||
75a70cf9 | 175 | /* Determine if statement T is inside an EH region in function IFUN. |
e38def9c | 176 | Positive numbers indicate a landing pad index; negative numbers |
177 | indicate a MUST_NOT_THROW region index; zero indicates that the | |
178 | statement is not recorded in the region table. */ | |
75a70cf9 | 179 | |
4ee9c684 | 180 | int |
e38def9c | 181 | lookup_stmt_eh_lp_fn (struct function *ifun, gimple t) |
4ee9c684 | 182 | { |
183 | struct throw_stmt_node *p, n; | |
184 | ||
e38def9c | 185 | if (ifun->eh->throw_stmt_table == NULL) |
186 | return 0; | |
4ee9c684 | 187 | |
75a70cf9 | 188 | n.stmt = t; |
e38def9c | 189 | p = (struct throw_stmt_node *) htab_find (ifun->eh->throw_stmt_table, &n); |
190 | return p ? p->lp_nr : 0; | |
4ee9c684 | 191 | } |
192 | ||
e38def9c | 193 | /* Likewise, but always use the current function. */ |
75a70cf9 | 194 | |
b3f1469f | 195 | int |
e38def9c | 196 | lookup_stmt_eh_lp (gimple t) |
b3f1469f | 197 | { |
198 | /* We can get called from initialized data when -fnon-call-exceptions | |
199 | is on; prevent crash. */ | |
200 | if (!cfun) | |
e38def9c | 201 | return 0; |
202 | return lookup_stmt_eh_lp_fn (cfun, t); | |
b3f1469f | 203 | } |
4ee9c684 | 204 | |
75a70cf9 | 205 | /* First pass of EH node decomposition. Build up a tree of GIMPLE_TRY_FINALLY |
4ee9c684 | 206 | nodes and LABEL_DECL nodes. We will use this during the second phase to |
207 | determine if a goto leaves the body of a TRY_FINALLY_EXPR node. */ | |
208 | ||
209 | struct finally_tree_node | |
210 | { | |
75a70cf9 | 211 | /* When storing a GIMPLE_TRY, we have to record a gimple. However |
212 | when deciding whether a GOTO to a certain LABEL_DECL (which is a | |
213 | tree) leaves the TRY block, its necessary to record a tree in | |
214 | this field. Thus a treemple is used. */ | |
e38def9c | 215 | treemple child; |
75a70cf9 | 216 | gimple parent; |
4ee9c684 | 217 | }; |
218 | ||
219 | /* Note that this table is *not* marked GTY. It is short-lived. */ | |
220 | static htab_t finally_tree; | |
221 | ||
222 | static void | |
75a70cf9 | 223 | record_in_finally_tree (treemple child, gimple parent) |
4ee9c684 | 224 | { |
225 | struct finally_tree_node *n; | |
226 | void **slot; | |
227 | ||
680a19b9 | 228 | n = XNEW (struct finally_tree_node); |
4ee9c684 | 229 | n->child = child; |
230 | n->parent = parent; | |
231 | ||
232 | slot = htab_find_slot (finally_tree, n, INSERT); | |
8c0963c4 | 233 | gcc_assert (!*slot); |
4ee9c684 | 234 | *slot = n; |
235 | } | |
236 | ||
237 | static void | |
75a70cf9 | 238 | collect_finally_tree (gimple stmt, gimple region); |
239 | ||
e38def9c | 240 | /* Go through the gimple sequence. Works with collect_finally_tree to |
75a70cf9 | 241 | record all GIMPLE_LABEL and GIMPLE_TRY statements. */ |
242 | ||
243 | static void | |
244 | collect_finally_tree_1 (gimple_seq seq, gimple region) | |
4ee9c684 | 245 | { |
75a70cf9 | 246 | gimple_stmt_iterator gsi; |
4ee9c684 | 247 | |
75a70cf9 | 248 | for (gsi = gsi_start (seq); !gsi_end_p (gsi); gsi_next (&gsi)) |
249 | collect_finally_tree (gsi_stmt (gsi), region); | |
250 | } | |
4ee9c684 | 251 | |
75a70cf9 | 252 | static void |
253 | collect_finally_tree (gimple stmt, gimple region) | |
254 | { | |
255 | treemple temp; | |
256 | ||
257 | switch (gimple_code (stmt)) | |
258 | { | |
259 | case GIMPLE_LABEL: | |
260 | temp.t = gimple_label_label (stmt); | |
261 | record_in_finally_tree (temp, region); | |
262 | break; | |
4ee9c684 | 263 | |
75a70cf9 | 264 | case GIMPLE_TRY: |
265 | if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY) | |
266 | { | |
267 | temp.g = stmt; | |
268 | record_in_finally_tree (temp, region); | |
269 | collect_finally_tree_1 (gimple_try_eval (stmt), stmt); | |
270 | collect_finally_tree_1 (gimple_try_cleanup (stmt), region); | |
271 | } | |
272 | else if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH) | |
273 | { | |
274 | collect_finally_tree_1 (gimple_try_eval (stmt), region); | |
275 | collect_finally_tree_1 (gimple_try_cleanup (stmt), region); | |
276 | } | |
277 | break; | |
4ee9c684 | 278 | |
75a70cf9 | 279 | case GIMPLE_CATCH: |
280 | collect_finally_tree_1 (gimple_catch_handler (stmt), region); | |
281 | break; | |
4ee9c684 | 282 | |
75a70cf9 | 283 | case GIMPLE_EH_FILTER: |
284 | collect_finally_tree_1 (gimple_eh_filter_failure (stmt), region); | |
4ee9c684 | 285 | break; |
286 | ||
287 | default: | |
288 | /* A type, a decl, or some kind of statement that we're not | |
289 | interested in. Don't walk them. */ | |
290 | break; | |
291 | } | |
292 | } | |
293 | ||
75a70cf9 | 294 | |
4ee9c684 | 295 | /* Use the finally tree to determine if a jump from START to TARGET |
296 | would leave the try_finally node that START lives in. */ | |
297 | ||
298 | static bool | |
75a70cf9 | 299 | outside_finally_tree (treemple start, gimple target) |
4ee9c684 | 300 | { |
301 | struct finally_tree_node n, *p; | |
302 | ||
303 | do | |
304 | { | |
305 | n.child = start; | |
680a19b9 | 306 | p = (struct finally_tree_node *) htab_find (finally_tree, &n); |
4ee9c684 | 307 | if (!p) |
308 | return true; | |
75a70cf9 | 309 | start.g = p->parent; |
4ee9c684 | 310 | } |
75a70cf9 | 311 | while (start.g != target); |
4ee9c684 | 312 | |
313 | return false; | |
314 | } | |
75a70cf9 | 315 | |
316 | /* Second pass of EH node decomposition. Actually transform the GIMPLE_TRY | |
317 | nodes into a set of gotos, magic labels, and eh regions. | |
4ee9c684 | 318 | The eh region creation is straight-forward, but frobbing all the gotos |
319 | and such into shape isn't. */ | |
320 | ||
48e1416a | 321 | /* The sequence into which we record all EH stuff. This will be |
e38def9c | 322 | placed at the end of the function when we're all done. */ |
323 | static gimple_seq eh_seq; | |
324 | ||
325 | /* Record whether an EH region contains something that can throw, | |
326 | indexed by EH region number. */ | |
55d6d4e4 | 327 | static bitmap eh_region_may_contain_throw_map; |
e38def9c | 328 | |
0b09525f | 329 | /* The GOTO_QUEUE is is an array of GIMPLE_GOTO and GIMPLE_RETURN |
330 | statements that are seen to escape this GIMPLE_TRY_FINALLY node. | |
331 | The idea is to record a gimple statement for everything except for | |
332 | the conditionals, which get their labels recorded. Since labels are | |
333 | of type 'tree', we need this node to store both gimple and tree | |
334 | objects. REPL_STMT is the sequence used to replace the goto/return | |
335 | statement. CONT_STMT is used to store the statement that allows | |
336 | the return/goto to jump to the original destination. */ | |
337 | ||
338 | struct goto_queue_node | |
339 | { | |
340 | treemple stmt; | |
341 | gimple_seq repl_stmt; | |
342 | gimple cont_stmt; | |
343 | int index; | |
344 | /* This is used when index >= 0 to indicate that stmt is a label (as | |
345 | opposed to a goto stmt). */ | |
346 | int is_label; | |
347 | }; | |
348 | ||
4ee9c684 | 349 | /* State of the world while lowering. */ |
350 | ||
351 | struct leh_state | |
352 | { | |
ac13e8d9 | 353 | /* What's "current" while constructing the eh region tree. These |
4ee9c684 | 354 | correspond to variables of the same name in cfun->eh, which we |
355 | don't have easy access to. */ | |
e38def9c | 356 | eh_region cur_region; |
357 | ||
358 | /* What's "current" for the purposes of __builtin_eh_pointer. For | |
359 | a CATCH, this is the associated TRY. For an EH_FILTER, this is | |
360 | the associated ALLOWED_EXCEPTIONS, etc. */ | |
361 | eh_region ehp_region; | |
4ee9c684 | 362 | |
363 | /* Processing of TRY_FINALLY requires a bit more state. This is | |
364 | split out into a separate structure so that we don't have to | |
365 | copy so much when processing other nodes. */ | |
366 | struct leh_tf_state *tf; | |
367 | }; | |
368 | ||
369 | struct leh_tf_state | |
370 | { | |
75a70cf9 | 371 | /* Pointer to the GIMPLE_TRY_FINALLY node under discussion. The |
372 | try_finally_expr is the original GIMPLE_TRY_FINALLY. We need to retain | |
373 | this so that outside_finally_tree can reliably reference the tree used | |
374 | in the collect_finally_tree data structures. */ | |
375 | gimple try_finally_expr; | |
376 | gimple top_p; | |
e38def9c | 377 | |
75a70cf9 | 378 | /* While lowering a top_p usually it is expanded into multiple statements, |
379 | thus we need the following field to store them. */ | |
380 | gimple_seq top_p_seq; | |
4ee9c684 | 381 | |
382 | /* The state outside this try_finally node. */ | |
383 | struct leh_state *outer; | |
384 | ||
385 | /* The exception region created for it. */ | |
e38def9c | 386 | eh_region region; |
4ee9c684 | 387 | |
0b09525f | 388 | /* The goto queue. */ |
389 | struct goto_queue_node *goto_queue; | |
4ee9c684 | 390 | size_t goto_queue_size; |
391 | size_t goto_queue_active; | |
392 | ||
f0b5f617 | 393 | /* Pointer map to help in searching goto_queue when it is large. */ |
46699809 | 394 | struct pointer_map_t *goto_queue_map; |
395 | ||
4ee9c684 | 396 | /* The set of unique labels seen as entries in the goto queue. */ |
8cb529a5 | 397 | VEC(tree,heap) *dest_array; |
4ee9c684 | 398 | |
399 | /* A label to be added at the end of the completed transformed | |
400 | sequence. It will be set if may_fallthru was true *at one time*, | |
401 | though subsequent transformations may have cleared that flag. */ | |
402 | tree fallthru_label; | |
403 | ||
4ee9c684 | 404 | /* True if it is possible to fall out the bottom of the try block. |
405 | Cleared if the fallthru is converted to a goto. */ | |
406 | bool may_fallthru; | |
407 | ||
75a70cf9 | 408 | /* True if any entry in goto_queue is a GIMPLE_RETURN. */ |
4ee9c684 | 409 | bool may_return; |
410 | ||
411 | /* True if the finally block can receive an exception edge. | |
412 | Cleared if the exception case is handled by code duplication. */ | |
413 | bool may_throw; | |
414 | }; | |
415 | ||
e38def9c | 416 | static gimple_seq lower_eh_must_not_throw (struct leh_state *, gimple); |
4ee9c684 | 417 | |
4ee9c684 | 418 | /* Search for STMT in the goto queue. Return the replacement, |
419 | or null if the statement isn't in the queue. */ | |
420 | ||
46699809 | 421 | #define LARGE_GOTO_QUEUE 20 |
422 | ||
75a70cf9 | 423 | static void lower_eh_constructs_1 (struct leh_state *state, gimple_seq seq); |
424 | ||
425 | static gimple_seq | |
426 | find_goto_replacement (struct leh_tf_state *tf, treemple stmt) | |
4ee9c684 | 427 | { |
46699809 | 428 | unsigned int i; |
429 | void **slot; | |
430 | ||
431 | if (tf->goto_queue_active < LARGE_GOTO_QUEUE) | |
432 | { | |
433 | for (i = 0; i < tf->goto_queue_active; i++) | |
75a70cf9 | 434 | if ( tf->goto_queue[i].stmt.g == stmt.g) |
46699809 | 435 | return tf->goto_queue[i].repl_stmt; |
436 | return NULL; | |
437 | } | |
438 | ||
439 | /* If we have a large number of entries in the goto_queue, create a | |
440 | pointer map and use that for searching. */ | |
441 | ||
442 | if (!tf->goto_queue_map) | |
443 | { | |
444 | tf->goto_queue_map = pointer_map_create (); | |
445 | for (i = 0; i < tf->goto_queue_active; i++) | |
446 | { | |
75a70cf9 | 447 | slot = pointer_map_insert (tf->goto_queue_map, |
448 | tf->goto_queue[i].stmt.g); | |
46699809 | 449 | gcc_assert (*slot == NULL); |
75a70cf9 | 450 | *slot = &tf->goto_queue[i]; |
46699809 | 451 | } |
452 | } | |
453 | ||
75a70cf9 | 454 | slot = pointer_map_contains (tf->goto_queue_map, stmt.g); |
46699809 | 455 | if (slot != NULL) |
456 | return (((struct goto_queue_node *) *slot)->repl_stmt); | |
457 | ||
458 | return NULL; | |
4ee9c684 | 459 | } |
460 | ||
461 | /* A subroutine of replace_goto_queue_1. Handles the sub-clauses of a | |
75a70cf9 | 462 | lowered GIMPLE_COND. If, by chance, the replacement is a simple goto, |
4ee9c684 | 463 | then we can just splat it in, otherwise we add the new stmts immediately |
75a70cf9 | 464 | after the GIMPLE_COND and redirect. */ |
4ee9c684 | 465 | |
466 | static void | |
467 | replace_goto_queue_cond_clause (tree *tp, struct leh_tf_state *tf, | |
75a70cf9 | 468 | gimple_stmt_iterator *gsi) |
4ee9c684 | 469 | { |
75a70cf9 | 470 | tree label; |
f4e36c33 | 471 | gimple_seq new_seq; |
75a70cf9 | 472 | treemple temp; |
e60a6f7b | 473 | location_t loc = gimple_location (gsi_stmt (*gsi)); |
4ee9c684 | 474 | |
75a70cf9 | 475 | temp.tp = tp; |
f4e36c33 | 476 | new_seq = find_goto_replacement (tf, temp); |
477 | if (!new_seq) | |
4ee9c684 | 478 | return; |
479 | ||
f4e36c33 | 480 | if (gimple_seq_singleton_p (new_seq) |
481 | && gimple_code (gimple_seq_first_stmt (new_seq)) == GIMPLE_GOTO) | |
4ee9c684 | 482 | { |
f4e36c33 | 483 | *tp = gimple_goto_dest (gimple_seq_first_stmt (new_seq)); |
4ee9c684 | 484 | return; |
485 | } | |
486 | ||
e60a6f7b | 487 | label = create_artificial_label (loc); |
75a70cf9 | 488 | /* Set the new label for the GIMPLE_COND */ |
489 | *tp = label; | |
4ee9c684 | 490 | |
75a70cf9 | 491 | gsi_insert_after (gsi, gimple_build_label (label), GSI_CONTINUE_LINKING); |
f4e36c33 | 492 | gsi_insert_seq_after (gsi, gimple_seq_copy (new_seq), GSI_CONTINUE_LINKING); |
4ee9c684 | 493 | } |
494 | ||
ac13e8d9 | 495 | /* The real work of replace_goto_queue. Returns with TSI updated to |
4ee9c684 | 496 | point to the next statement. */ |
497 | ||
75a70cf9 | 498 | static void replace_goto_queue_stmt_list (gimple_seq, struct leh_tf_state *); |
4ee9c684 | 499 | |
500 | static void | |
75a70cf9 | 501 | replace_goto_queue_1 (gimple stmt, struct leh_tf_state *tf, |
502 | gimple_stmt_iterator *gsi) | |
4ee9c684 | 503 | { |
75a70cf9 | 504 | gimple_seq seq; |
505 | treemple temp; | |
506 | temp.g = NULL; | |
507 | ||
508 | switch (gimple_code (stmt)) | |
4ee9c684 | 509 | { |
75a70cf9 | 510 | case GIMPLE_GOTO: |
511 | case GIMPLE_RETURN: | |
512 | temp.g = stmt; | |
513 | seq = find_goto_replacement (tf, temp); | |
514 | if (seq) | |
4ee9c684 | 515 | { |
75a70cf9 | 516 | gsi_insert_seq_before (gsi, gimple_seq_copy (seq), GSI_SAME_STMT); |
517 | gsi_remove (gsi, false); | |
4ee9c684 | 518 | return; |
519 | } | |
520 | break; | |
521 | ||
75a70cf9 | 522 | case GIMPLE_COND: |
523 | replace_goto_queue_cond_clause (gimple_op_ptr (stmt, 2), tf, gsi); | |
524 | replace_goto_queue_cond_clause (gimple_op_ptr (stmt, 3), tf, gsi); | |
4ee9c684 | 525 | break; |
526 | ||
75a70cf9 | 527 | case GIMPLE_TRY: |
528 | replace_goto_queue_stmt_list (gimple_try_eval (stmt), tf); | |
529 | replace_goto_queue_stmt_list (gimple_try_cleanup (stmt), tf); | |
4ee9c684 | 530 | break; |
75a70cf9 | 531 | case GIMPLE_CATCH: |
532 | replace_goto_queue_stmt_list (gimple_catch_handler (stmt), tf); | |
4ee9c684 | 533 | break; |
75a70cf9 | 534 | case GIMPLE_EH_FILTER: |
535 | replace_goto_queue_stmt_list (gimple_eh_filter_failure (stmt), tf); | |
4ee9c684 | 536 | break; |
537 | ||
4ee9c684 | 538 | default: |
539 | /* These won't have gotos in them. */ | |
540 | break; | |
541 | } | |
542 | ||
75a70cf9 | 543 | gsi_next (gsi); |
4ee9c684 | 544 | } |
545 | ||
75a70cf9 | 546 | /* A subroutine of replace_goto_queue. Handles GIMPLE_SEQ. */ |
4ee9c684 | 547 | |
548 | static void | |
75a70cf9 | 549 | replace_goto_queue_stmt_list (gimple_seq seq, struct leh_tf_state *tf) |
4ee9c684 | 550 | { |
75a70cf9 | 551 | gimple_stmt_iterator gsi = gsi_start (seq); |
552 | ||
553 | while (!gsi_end_p (gsi)) | |
554 | replace_goto_queue_1 (gsi_stmt (gsi), tf, &gsi); | |
4ee9c684 | 555 | } |
556 | ||
557 | /* Replace all goto queue members. */ | |
558 | ||
559 | static void | |
560 | replace_goto_queue (struct leh_tf_state *tf) | |
561 | { | |
82a8c0dd | 562 | if (tf->goto_queue_active == 0) |
563 | return; | |
75a70cf9 | 564 | replace_goto_queue_stmt_list (tf->top_p_seq, tf); |
fa5d8988 | 565 | replace_goto_queue_stmt_list (eh_seq, tf); |
4ee9c684 | 566 | } |
567 | ||
75a70cf9 | 568 | /* Add a new record to the goto queue contained in TF. NEW_STMT is the |
569 | data to be added, IS_LABEL indicates whether NEW_STMT is a label or | |
570 | a gimple return. */ | |
4ee9c684 | 571 | |
572 | static void | |
75a70cf9 | 573 | record_in_goto_queue (struct leh_tf_state *tf, |
574 | treemple new_stmt, | |
575 | int index, | |
576 | bool is_label) | |
4ee9c684 | 577 | { |
4ee9c684 | 578 | size_t active, size; |
75a70cf9 | 579 | struct goto_queue_node *q; |
4ee9c684 | 580 | |
46699809 | 581 | gcc_assert (!tf->goto_queue_map); |
582 | ||
4ee9c684 | 583 | active = tf->goto_queue_active; |
584 | size = tf->goto_queue_size; | |
585 | if (active >= size) | |
586 | { | |
587 | size = (size ? size * 2 : 32); | |
588 | tf->goto_queue_size = size; | |
589 | tf->goto_queue | |
680a19b9 | 590 | = XRESIZEVEC (struct goto_queue_node, tf->goto_queue, size); |
4ee9c684 | 591 | } |
592 | ||
593 | q = &tf->goto_queue[active]; | |
594 | tf->goto_queue_active = active + 1; | |
ac13e8d9 | 595 | |
4ee9c684 | 596 | memset (q, 0, sizeof (*q)); |
75a70cf9 | 597 | q->stmt = new_stmt; |
4ee9c684 | 598 | q->index = index; |
75a70cf9 | 599 | q->is_label = is_label; |
600 | } | |
601 | ||
602 | /* Record the LABEL label in the goto queue contained in TF. | |
603 | TF is not null. */ | |
604 | ||
605 | static void | |
606 | record_in_goto_queue_label (struct leh_tf_state *tf, treemple stmt, tree label) | |
607 | { | |
608 | int index; | |
609 | treemple temp, new_stmt; | |
610 | ||
611 | if (!label) | |
612 | return; | |
613 | ||
614 | /* Computed and non-local gotos do not get processed. Given | |
615 | their nature we can neither tell whether we've escaped the | |
616 | finally block nor redirect them if we knew. */ | |
617 | if (TREE_CODE (label) != LABEL_DECL) | |
618 | return; | |
619 | ||
620 | /* No need to record gotos that don't leave the try block. */ | |
621 | temp.t = label; | |
622 | if (!outside_finally_tree (temp, tf->try_finally_expr)) | |
623 | return; | |
624 | ||
625 | if (! tf->dest_array) | |
626 | { | |
627 | tf->dest_array = VEC_alloc (tree, heap, 10); | |
628 | VEC_quick_push (tree, tf->dest_array, label); | |
629 | index = 0; | |
630 | } | |
631 | else | |
632 | { | |
633 | int n = VEC_length (tree, tf->dest_array); | |
634 | for (index = 0; index < n; ++index) | |
635 | if (VEC_index (tree, tf->dest_array, index) == label) | |
636 | break; | |
637 | if (index == n) | |
638 | VEC_safe_push (tree, heap, tf->dest_array, label); | |
639 | } | |
640 | ||
641 | /* In the case of a GOTO we want to record the destination label, | |
642 | since with a GIMPLE_COND we have an easy access to the then/else | |
643 | labels. */ | |
644 | new_stmt = stmt; | |
645 | record_in_goto_queue (tf, new_stmt, index, true); | |
75a70cf9 | 646 | } |
647 | ||
648 | /* For any GIMPLE_GOTO or GIMPLE_RETURN, decide whether it leaves a try_finally | |
649 | node, and if so record that fact in the goto queue associated with that | |
650 | try_finally node. */ | |
651 | ||
652 | static void | |
653 | maybe_record_in_goto_queue (struct leh_state *state, gimple stmt) | |
654 | { | |
655 | struct leh_tf_state *tf = state->tf; | |
656 | treemple new_stmt; | |
657 | ||
658 | if (!tf) | |
659 | return; | |
660 | ||
661 | switch (gimple_code (stmt)) | |
662 | { | |
663 | case GIMPLE_COND: | |
664 | new_stmt.tp = gimple_op_ptr (stmt, 2); | |
665 | record_in_goto_queue_label (tf, new_stmt, gimple_cond_true_label (stmt)); | |
666 | new_stmt.tp = gimple_op_ptr (stmt, 3); | |
667 | record_in_goto_queue_label (tf, new_stmt, gimple_cond_false_label (stmt)); | |
668 | break; | |
669 | case GIMPLE_GOTO: | |
670 | new_stmt.g = stmt; | |
671 | record_in_goto_queue_label (tf, new_stmt, gimple_goto_dest (stmt)); | |
672 | break; | |
673 | ||
674 | case GIMPLE_RETURN: | |
675 | tf->may_return = true; | |
676 | new_stmt.g = stmt; | |
677 | record_in_goto_queue (tf, new_stmt, -1, false); | |
678 | break; | |
679 | ||
680 | default: | |
681 | gcc_unreachable (); | |
682 | } | |
4ee9c684 | 683 | } |
684 | ||
75a70cf9 | 685 | |
4ee9c684 | 686 | #ifdef ENABLE_CHECKING |
75a70cf9 | 687 | /* We do not process GIMPLE_SWITCHes for now. As long as the original source |
4ee9c684 | 688 | was in fact structured, and we've not yet done jump threading, then none |
75a70cf9 | 689 | of the labels will leave outer GIMPLE_TRY_FINALLY nodes. Verify this. */ |
4ee9c684 | 690 | |
691 | static void | |
75a70cf9 | 692 | verify_norecord_switch_expr (struct leh_state *state, gimple switch_expr) |
4ee9c684 | 693 | { |
694 | struct leh_tf_state *tf = state->tf; | |
695 | size_t i, n; | |
4ee9c684 | 696 | |
697 | if (!tf) | |
698 | return; | |
699 | ||
75a70cf9 | 700 | n = gimple_switch_num_labels (switch_expr); |
4ee9c684 | 701 | |
702 | for (i = 0; i < n; ++i) | |
703 | { | |
75a70cf9 | 704 | treemple temp; |
705 | tree lab = CASE_LABEL (gimple_switch_label (switch_expr, i)); | |
706 | temp.t = lab; | |
707 | gcc_assert (!outside_finally_tree (temp, tf->try_finally_expr)); | |
4ee9c684 | 708 | } |
709 | } | |
710 | #else | |
711 | #define verify_norecord_switch_expr(state, switch_expr) | |
712 | #endif | |
713 | ||
714 | /* Redirect a RETURN_EXPR pointed to by STMT_P to FINLAB. Place in CONT_P | |
715 | whatever is needed to finish the return. If MOD is non-null, insert it | |
716 | before the new branch. RETURN_VALUE_P is a cache containing a temporary | |
0bed3869 | 717 | variable to be used in manipulating the value returned from the function. */ |
4ee9c684 | 718 | |
719 | static void | |
75a70cf9 | 720 | do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod, |
4ee9c684 | 721 | tree *return_value_p) |
722 | { | |
75a70cf9 | 723 | tree ret_expr; |
724 | gimple x; | |
725 | ||
726 | /* In the case of a return, the queue node must be a gimple statement. */ | |
727 | gcc_assert (!q->is_label); | |
728 | ||
729 | ret_expr = gimple_return_retval (q->stmt.g); | |
4ee9c684 | 730 | |
731 | if (ret_expr) | |
732 | { | |
75a70cf9 | 733 | if (!*return_value_p) |
734 | *return_value_p = ret_expr; | |
735 | else | |
736 | gcc_assert (*return_value_p == ret_expr); | |
737 | q->cont_stmt = q->stmt.g; | |
4ee9c684 | 738 | /* The nasty part about redirecting the return value is that the |
739 | return value itself is to be computed before the FINALLY block | |
740 | is executed. e.g. | |
741 | ||
742 | int x; | |
743 | int foo (void) | |
744 | { | |
745 | x = 0; | |
746 | try { | |
747 | return x; | |
748 | } finally { | |
749 | x++; | |
750 | } | |
751 | } | |
752 | ||
753 | should return 0, not 1. Arrange for this to happen by copying | |
754 | computed the return value into a local temporary. This also | |
755 | allows us to redirect multiple return statements through the | |
756 | same destination block; whether this is a net win or not really | |
757 | depends, I guess, but it does make generation of the switch in | |
758 | lower_try_finally_switch easier. */ | |
759 | ||
75a70cf9 | 760 | if (TREE_CODE (ret_expr) == RESULT_DECL) |
4ee9c684 | 761 | { |
762 | if (!*return_value_p) | |
763 | *return_value_p = ret_expr; | |
4ee9c684 | 764 | else |
8c0963c4 | 765 | gcc_assert (*return_value_p == ret_expr); |
75a70cf9 | 766 | q->cont_stmt = q->stmt.g; |
4ee9c684 | 767 | } |
75a70cf9 | 768 | else |
769 | gcc_unreachable (); | |
4ee9c684 | 770 | } |
771 | else | |
4ee9c684 | 772 | /* If we don't return a value, all return statements are the same. */ |
75a70cf9 | 773 | q->cont_stmt = q->stmt.g; |
774 | ||
775 | if (!q->repl_stmt) | |
776 | q->repl_stmt = gimple_seq_alloc (); | |
4ee9c684 | 777 | |
778 | if (mod) | |
75a70cf9 | 779 | gimple_seq_add_seq (&q->repl_stmt, mod); |
4ee9c684 | 780 | |
75a70cf9 | 781 | x = gimple_build_goto (finlab); |
782 | gimple_seq_add_stmt (&q->repl_stmt, x); | |
4ee9c684 | 783 | } |
784 | ||
75a70cf9 | 785 | /* Similar, but easier, for GIMPLE_GOTO. */ |
4ee9c684 | 786 | |
787 | static void | |
75a70cf9 | 788 | do_goto_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod, |
789 | struct leh_tf_state *tf) | |
4ee9c684 | 790 | { |
75a70cf9 | 791 | gimple x; |
792 | ||
793 | gcc_assert (q->is_label); | |
794 | if (!q->repl_stmt) | |
795 | q->repl_stmt = gimple_seq_alloc (); | |
796 | ||
e38def9c | 797 | q->cont_stmt = gimple_build_goto (VEC_index (tree, tf->dest_array, q->index)); |
4ee9c684 | 798 | |
4ee9c684 | 799 | if (mod) |
75a70cf9 | 800 | gimple_seq_add_seq (&q->repl_stmt, mod); |
4ee9c684 | 801 | |
75a70cf9 | 802 | x = gimple_build_goto (finlab); |
803 | gimple_seq_add_stmt (&q->repl_stmt, x); | |
4ee9c684 | 804 | } |
805 | ||
e38def9c | 806 | /* Emit a standard landing pad sequence into SEQ for REGION. */ |
807 | ||
808 | static void | |
809 | emit_post_landing_pad (gimple_seq *seq, eh_region region) | |
810 | { | |
811 | eh_landing_pad lp = region->landing_pads; | |
812 | gimple x; | |
813 | ||
814 | if (lp == NULL) | |
815 | lp = gen_eh_landing_pad (region); | |
816 | ||
817 | lp->post_landing_pad = create_artificial_label (UNKNOWN_LOCATION); | |
818 | EH_LANDING_PAD_NR (lp->post_landing_pad) = lp->index; | |
819 | ||
820 | x = gimple_build_label (lp->post_landing_pad); | |
821 | gimple_seq_add_stmt (seq, x); | |
822 | } | |
823 | ||
824 | /* Emit a RESX statement into SEQ for REGION. */ | |
825 | ||
826 | static void | |
827 | emit_resx (gimple_seq *seq, eh_region region) | |
828 | { | |
829 | gimple x = gimple_build_resx (region->index); | |
830 | gimple_seq_add_stmt (seq, x); | |
831 | if (region->outer) | |
832 | record_stmt_eh_region (region->outer, x); | |
833 | } | |
834 | ||
835 | /* Emit an EH_DISPATCH statement into SEQ for REGION. */ | |
836 | ||
837 | static void | |
838 | emit_eh_dispatch (gimple_seq *seq, eh_region region) | |
839 | { | |
840 | gimple x = gimple_build_eh_dispatch (region->index); | |
841 | gimple_seq_add_stmt (seq, x); | |
842 | } | |
843 | ||
844 | /* Note that the current EH region may contain a throw, or a | |
845 | call to a function which itself may contain a throw. */ | |
846 | ||
847 | static void | |
848 | note_eh_region_may_contain_throw (eh_region region) | |
849 | { | |
6ef9bbe0 | 850 | while (bitmap_set_bit (eh_region_may_contain_throw_map, region->index)) |
e38def9c | 851 | { |
e38def9c | 852 | region = region->outer; |
853 | if (region == NULL) | |
854 | break; | |
855 | } | |
856 | } | |
857 | ||
55d6d4e4 | 858 | /* Check if REGION has been marked as containing a throw. If REGION is |
859 | NULL, this predicate is false. */ | |
860 | ||
861 | static inline bool | |
862 | eh_region_may_contain_throw (eh_region r) | |
863 | { | |
864 | return r && bitmap_bit_p (eh_region_may_contain_throw_map, r->index); | |
865 | } | |
866 | ||
4ee9c684 | 867 | /* We want to transform |
868 | try { body; } catch { stuff; } | |
869 | to | |
e38def9c | 870 | normal_seqence: |
871 | body; | |
872 | over: | |
873 | eh_seqence: | |
874 | landing_pad: | |
875 | stuff; | |
876 | goto over; | |
877 | ||
878 | TP is a GIMPLE_TRY node. REGION is the region whose post_landing_pad | |
4ee9c684 | 879 | should be placed before the second operand, or NULL. OVER is |
880 | an existing label that should be put at the exit, or NULL. */ | |
881 | ||
75a70cf9 | 882 | static gimple_seq |
e38def9c | 883 | frob_into_branch_around (gimple tp, eh_region region, tree over) |
4ee9c684 | 884 | { |
75a70cf9 | 885 | gimple x; |
886 | gimple_seq cleanup, result; | |
e60a6f7b | 887 | location_t loc = gimple_location (tp); |
4ee9c684 | 888 | |
75a70cf9 | 889 | cleanup = gimple_try_cleanup (tp); |
890 | result = gimple_try_eval (tp); | |
4ee9c684 | 891 | |
e38def9c | 892 | if (region) |
893 | emit_post_landing_pad (&eh_seq, region); | |
894 | ||
895 | if (gimple_seq_may_fallthru (cleanup)) | |
4ee9c684 | 896 | { |
897 | if (!over) | |
e60a6f7b | 898 | over = create_artificial_label (loc); |
75a70cf9 | 899 | x = gimple_build_goto (over); |
e38def9c | 900 | gimple_seq_add_stmt (&cleanup, x); |
4ee9c684 | 901 | } |
e38def9c | 902 | gimple_seq_add_seq (&eh_seq, cleanup); |
4ee9c684 | 903 | |
904 | if (over) | |
905 | { | |
75a70cf9 | 906 | x = gimple_build_label (over); |
907 | gimple_seq_add_stmt (&result, x); | |
4ee9c684 | 908 | } |
75a70cf9 | 909 | return result; |
4ee9c684 | 910 | } |
911 | ||
912 | /* A subroutine of lower_try_finally. Duplicate the tree rooted at T. | |
913 | Make sure to record all new labels found. */ | |
914 | ||
75a70cf9 | 915 | static gimple_seq |
916 | lower_try_finally_dup_block (gimple_seq seq, struct leh_state *outer_state) | |
4ee9c684 | 917 | { |
75a70cf9 | 918 | gimple region = NULL; |
919 | gimple_seq new_seq; | |
4ee9c684 | 920 | |
75a70cf9 | 921 | new_seq = copy_gimple_seq_and_replace_locals (seq); |
4ee9c684 | 922 | |
923 | if (outer_state->tf) | |
924 | region = outer_state->tf->try_finally_expr; | |
75a70cf9 | 925 | collect_finally_tree_1 (new_seq, region); |
4ee9c684 | 926 | |
75a70cf9 | 927 | return new_seq; |
4ee9c684 | 928 | } |
929 | ||
930 | /* A subroutine of lower_try_finally. Create a fallthru label for | |
931 | the given try_finally state. The only tricky bit here is that | |
932 | we have to make sure to record the label in our outer context. */ | |
933 | ||
934 | static tree | |
935 | lower_try_finally_fallthru_label (struct leh_tf_state *tf) | |
936 | { | |
937 | tree label = tf->fallthru_label; | |
75a70cf9 | 938 | treemple temp; |
939 | ||
4ee9c684 | 940 | if (!label) |
941 | { | |
e60a6f7b | 942 | label = create_artificial_label (gimple_location (tf->try_finally_expr)); |
4ee9c684 | 943 | tf->fallthru_label = label; |
944 | if (tf->outer->tf) | |
75a70cf9 | 945 | { |
946 | temp.t = label; | |
947 | record_in_finally_tree (temp, tf->outer->tf->try_finally_expr); | |
948 | } | |
4ee9c684 | 949 | } |
950 | return label; | |
951 | } | |
952 | ||
596981c8 | 953 | /* A subroutine of lower_try_finally. If the eh_protect_cleanup_actions |
954 | langhook returns non-null, then the language requires that the exception | |
955 | path out of a try_finally be treated specially. To wit: the code within | |
956 | the finally block may not itself throw an exception. We have two choices | |
957 | here. First we can duplicate the finally block and wrap it in a | |
958 | must_not_throw region. Second, we can generate code like | |
4ee9c684 | 959 | |
960 | try { | |
961 | finally_block; | |
962 | } catch { | |
963 | if (fintmp == eh_edge) | |
964 | protect_cleanup_actions; | |
965 | } | |
966 | ||
967 | where "fintmp" is the temporary used in the switch statement generation | |
968 | alternative considered below. For the nonce, we always choose the first | |
ac13e8d9 | 969 | option. |
4ee9c684 | 970 | |
822e391f | 971 | THIS_STATE may be null if this is a try-cleanup, not a try-finally. */ |
4ee9c684 | 972 | |
973 | static void | |
974 | honor_protect_cleanup_actions (struct leh_state *outer_state, | |
975 | struct leh_state *this_state, | |
976 | struct leh_tf_state *tf) | |
977 | { | |
e38def9c | 978 | tree protect_cleanup_actions; |
75a70cf9 | 979 | gimple_stmt_iterator gsi; |
4ee9c684 | 980 | bool finally_may_fallthru; |
75a70cf9 | 981 | gimple_seq finally; |
982 | gimple x; | |
4ee9c684 | 983 | |
984 | /* First check for nothing to do. */ | |
596981c8 | 985 | if (lang_hooks.eh_protect_cleanup_actions == NULL) |
e38def9c | 986 | return; |
596981c8 | 987 | protect_cleanup_actions = lang_hooks.eh_protect_cleanup_actions (); |
e38def9c | 988 | if (protect_cleanup_actions == NULL) |
989 | return; | |
4ee9c684 | 990 | |
75a70cf9 | 991 | finally = gimple_try_cleanup (tf->top_p); |
75a70cf9 | 992 | finally_may_fallthru = gimple_seq_may_fallthru (finally); |
4ee9c684 | 993 | |
994 | /* Duplicate the FINALLY block. Only need to do this for try-finally, | |
995 | and not for cleanups. */ | |
996 | if (this_state) | |
997 | finally = lower_try_finally_dup_block (finally, outer_state); | |
998 | ||
0bc060a4 | 999 | /* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP |
1000 | set, the handler of the TRY_CATCH_EXPR is another cleanup which ought | |
1001 | to be in an enclosing scope, but needs to be implemented at this level | |
1002 | to avoid a nesting violation (see wrap_temporary_cleanups in | |
1003 | cp/decl.c). Since it's logically at an outer level, we should call | |
1004 | terminate before we get to it, so strip it away before adding the | |
1005 | MUST_NOT_THROW filter. */ | |
75a70cf9 | 1006 | gsi = gsi_start (finally); |
1007 | x = gsi_stmt (gsi); | |
e38def9c | 1008 | if (gimple_code (x) == GIMPLE_TRY |
75a70cf9 | 1009 | && gimple_try_kind (x) == GIMPLE_TRY_CATCH |
1010 | && gimple_try_catch_is_cleanup (x)) | |
0bc060a4 | 1011 | { |
75a70cf9 | 1012 | gsi_insert_seq_before (&gsi, gimple_try_eval (x), GSI_SAME_STMT); |
1013 | gsi_remove (&gsi, false); | |
0bc060a4 | 1014 | } |
1015 | ||
4ee9c684 | 1016 | /* Wrap the block with protect_cleanup_actions as the action. */ |
e38def9c | 1017 | x = gimple_build_eh_must_not_throw (protect_cleanup_actions); |
1018 | x = gimple_build_try (finally, gimple_seq_alloc_with_stmt (x), | |
1019 | GIMPLE_TRY_CATCH); | |
1020 | finally = lower_eh_must_not_throw (outer_state, x); | |
1021 | ||
1022 | /* Drop all of this into the exception sequence. */ | |
1023 | emit_post_landing_pad (&eh_seq, tf->region); | |
1024 | gimple_seq_add_seq (&eh_seq, finally); | |
1025 | if (finally_may_fallthru) | |
1026 | emit_resx (&eh_seq, tf->region); | |
4ee9c684 | 1027 | |
1028 | /* Having now been handled, EH isn't to be considered with | |
1029 | the rest of the outgoing edges. */ | |
1030 | tf->may_throw = false; | |
1031 | } | |
1032 | ||
1033 | /* A subroutine of lower_try_finally. We have determined that there is | |
1034 | no fallthru edge out of the finally block. This means that there is | |
1035 | no outgoing edge corresponding to any incoming edge. Restructure the | |
1036 | try_finally node for this special case. */ | |
1037 | ||
1038 | static void | |
75a70cf9 | 1039 | lower_try_finally_nofallthru (struct leh_state *state, |
1040 | struct leh_tf_state *tf) | |
4ee9c684 | 1041 | { |
75a70cf9 | 1042 | tree lab, return_val; |
1043 | gimple x; | |
1044 | gimple_seq finally; | |
4ee9c684 | 1045 | struct goto_queue_node *q, *qe; |
1046 | ||
e38def9c | 1047 | lab = create_artificial_label (gimple_location (tf->try_finally_expr)); |
4ee9c684 | 1048 | |
75a70cf9 | 1049 | /* We expect that tf->top_p is a GIMPLE_TRY. */ |
1050 | finally = gimple_try_cleanup (tf->top_p); | |
1051 | tf->top_p_seq = gimple_try_eval (tf->top_p); | |
4ee9c684 | 1052 | |
75a70cf9 | 1053 | x = gimple_build_label (lab); |
1054 | gimple_seq_add_stmt (&tf->top_p_seq, x); | |
4ee9c684 | 1055 | |
1056 | return_val = NULL; | |
1057 | q = tf->goto_queue; | |
1058 | qe = q + tf->goto_queue_active; | |
1059 | for (; q < qe; ++q) | |
1060 | if (q->index < 0) | |
1061 | do_return_redirection (q, lab, NULL, &return_val); | |
1062 | else | |
75a70cf9 | 1063 | do_goto_redirection (q, lab, NULL, tf); |
4ee9c684 | 1064 | |
1065 | replace_goto_queue (tf); | |
1066 | ||
75a70cf9 | 1067 | lower_eh_constructs_1 (state, finally); |
1068 | gimple_seq_add_seq (&tf->top_p_seq, finally); | |
e38def9c | 1069 | |
1070 | if (tf->may_throw) | |
1071 | { | |
1072 | emit_post_landing_pad (&eh_seq, tf->region); | |
1073 | ||
1074 | x = gimple_build_goto (lab); | |
1075 | gimple_seq_add_stmt (&eh_seq, x); | |
1076 | } | |
4ee9c684 | 1077 | } |
1078 | ||
1079 | /* A subroutine of lower_try_finally. We have determined that there is | |
1080 | exactly one destination of the finally block. Restructure the | |
1081 | try_finally node for this special case. */ | |
1082 | ||
1083 | static void | |
1084 | lower_try_finally_onedest (struct leh_state *state, struct leh_tf_state *tf) | |
1085 | { | |
1086 | struct goto_queue_node *q, *qe; | |
75a70cf9 | 1087 | gimple x; |
1088 | gimple_seq finally; | |
1089 | tree finally_label; | |
e60a6f7b | 1090 | location_t loc = gimple_location (tf->try_finally_expr); |
4ee9c684 | 1091 | |
75a70cf9 | 1092 | finally = gimple_try_cleanup (tf->top_p); |
1093 | tf->top_p_seq = gimple_try_eval (tf->top_p); | |
4ee9c684 | 1094 | |
75a70cf9 | 1095 | lower_eh_constructs_1 (state, finally); |
4ee9c684 | 1096 | |
1097 | if (tf->may_throw) | |
1098 | { | |
1099 | /* Only reachable via the exception edge. Add the given label to | |
1100 | the head of the FINALLY block. Append a RESX at the end. */ | |
e38def9c | 1101 | emit_post_landing_pad (&eh_seq, tf->region); |
1102 | gimple_seq_add_seq (&eh_seq, finally); | |
1103 | emit_resx (&eh_seq, tf->region); | |
4ee9c684 | 1104 | return; |
1105 | } | |
1106 | ||
1107 | if (tf->may_fallthru) | |
1108 | { | |
1109 | /* Only reachable via the fallthru edge. Do nothing but let | |
1110 | the two blocks run together; we'll fall out the bottom. */ | |
75a70cf9 | 1111 | gimple_seq_add_seq (&tf->top_p_seq, finally); |
4ee9c684 | 1112 | return; |
1113 | } | |
1114 | ||
e60a6f7b | 1115 | finally_label = create_artificial_label (loc); |
75a70cf9 | 1116 | x = gimple_build_label (finally_label); |
1117 | gimple_seq_add_stmt (&tf->top_p_seq, x); | |
4ee9c684 | 1118 | |
75a70cf9 | 1119 | gimple_seq_add_seq (&tf->top_p_seq, finally); |
4ee9c684 | 1120 | |
1121 | q = tf->goto_queue; | |
1122 | qe = q + tf->goto_queue_active; | |
1123 | ||
1124 | if (tf->may_return) | |
1125 | { | |
1126 | /* Reachable by return expressions only. Redirect them. */ | |
1127 | tree return_val = NULL; | |
1128 | for (; q < qe; ++q) | |
1129 | do_return_redirection (q, finally_label, NULL, &return_val); | |
1130 | replace_goto_queue (tf); | |
1131 | } | |
1132 | else | |
1133 | { | |
1134 | /* Reachable by goto expressions only. Redirect them. */ | |
1135 | for (; q < qe; ++q) | |
75a70cf9 | 1136 | do_goto_redirection (q, finally_label, NULL, tf); |
4ee9c684 | 1137 | replace_goto_queue (tf); |
ac13e8d9 | 1138 | |
8cb529a5 | 1139 | if (VEC_index (tree, tf->dest_array, 0) == tf->fallthru_label) |
4ee9c684 | 1140 | { |
1141 | /* Reachable by goto to fallthru label only. Redirect it | |
1142 | to the new label (already created, sadly), and do not | |
1143 | emit the final branch out, or the fallthru label. */ | |
1144 | tf->fallthru_label = NULL; | |
1145 | return; | |
1146 | } | |
1147 | } | |
1148 | ||
75a70cf9 | 1149 | /* Place the original return/goto to the original destination |
1150 | immediately after the finally block. */ | |
1151 | x = tf->goto_queue[0].cont_stmt; | |
1152 | gimple_seq_add_stmt (&tf->top_p_seq, x); | |
1153 | maybe_record_in_goto_queue (state, x); | |
4ee9c684 | 1154 | } |
1155 | ||
1156 | /* A subroutine of lower_try_finally. There are multiple edges incoming | |
1157 | and outgoing from the finally block. Implement this by duplicating the | |
1158 | finally block for every destination. */ | |
1159 | ||
1160 | static void | |
1161 | lower_try_finally_copy (struct leh_state *state, struct leh_tf_state *tf) | |
1162 | { | |
75a70cf9 | 1163 | gimple_seq finally; |
1164 | gimple_seq new_stmt; | |
1165 | gimple_seq seq; | |
1166 | gimple x; | |
1167 | tree tmp; | |
e60a6f7b | 1168 | location_t tf_loc = gimple_location (tf->try_finally_expr); |
4ee9c684 | 1169 | |
75a70cf9 | 1170 | finally = gimple_try_cleanup (tf->top_p); |
1171 | tf->top_p_seq = gimple_try_eval (tf->top_p); | |
1172 | new_stmt = NULL; | |
4ee9c684 | 1173 | |
1174 | if (tf->may_fallthru) | |
1175 | { | |
75a70cf9 | 1176 | seq = lower_try_finally_dup_block (finally, state); |
1177 | lower_eh_constructs_1 (state, seq); | |
1178 | gimple_seq_add_seq (&new_stmt, seq); | |
4ee9c684 | 1179 | |
75a70cf9 | 1180 | tmp = lower_try_finally_fallthru_label (tf); |
1181 | x = gimple_build_goto (tmp); | |
1182 | gimple_seq_add_stmt (&new_stmt, x); | |
4ee9c684 | 1183 | } |
1184 | ||
1185 | if (tf->may_throw) | |
1186 | { | |
75a70cf9 | 1187 | seq = lower_try_finally_dup_block (finally, state); |
1188 | lower_eh_constructs_1 (state, seq); | |
4ee9c684 | 1189 | |
2fabdfdf | 1190 | emit_post_landing_pad (&eh_seq, tf->region); |
1191 | gimple_seq_add_seq (&eh_seq, seq); | |
e38def9c | 1192 | emit_resx (&eh_seq, tf->region); |
4ee9c684 | 1193 | } |
1194 | ||
1195 | if (tf->goto_queue) | |
1196 | { | |
1197 | struct goto_queue_node *q, *qe; | |
1198 | tree return_val = NULL; | |
22347b24 | 1199 | int return_index, index; |
680a19b9 | 1200 | struct labels_s |
22347b24 | 1201 | { |
1202 | struct goto_queue_node *q; | |
1203 | tree label; | |
1204 | } *labels; | |
4ee9c684 | 1205 | |
8cb529a5 | 1206 | return_index = VEC_length (tree, tf->dest_array); |
680a19b9 | 1207 | labels = XCNEWVEC (struct labels_s, return_index + 1); |
4ee9c684 | 1208 | |
1209 | q = tf->goto_queue; | |
1210 | qe = q + tf->goto_queue_active; | |
1211 | for (; q < qe; q++) | |
1212 | { | |
22347b24 | 1213 | index = q->index < 0 ? return_index : q->index; |
1214 | ||
1215 | if (!labels[index].q) | |
1216 | labels[index].q = q; | |
1217 | } | |
1218 | ||
1219 | for (index = 0; index < return_index + 1; index++) | |
1220 | { | |
1221 | tree lab; | |
1222 | ||
1223 | q = labels[index].q; | |
1224 | if (! q) | |
1225 | continue; | |
1226 | ||
e60a6f7b | 1227 | lab = labels[index].label |
1228 | = create_artificial_label (tf_loc); | |
4ee9c684 | 1229 | |
1230 | if (index == return_index) | |
1231 | do_return_redirection (q, lab, NULL, &return_val); | |
1232 | else | |
75a70cf9 | 1233 | do_goto_redirection (q, lab, NULL, tf); |
4ee9c684 | 1234 | |
75a70cf9 | 1235 | x = gimple_build_label (lab); |
1236 | gimple_seq_add_stmt (&new_stmt, x); | |
4ee9c684 | 1237 | |
75a70cf9 | 1238 | seq = lower_try_finally_dup_block (finally, state); |
1239 | lower_eh_constructs_1 (state, seq); | |
1240 | gimple_seq_add_seq (&new_stmt, seq); | |
4ee9c684 | 1241 | |
75a70cf9 | 1242 | gimple_seq_add_stmt (&new_stmt, q->cont_stmt); |
22347b24 | 1243 | maybe_record_in_goto_queue (state, q->cont_stmt); |
4ee9c684 | 1244 | } |
22347b24 | 1245 | |
1246 | for (q = tf->goto_queue; q < qe; q++) | |
1247 | { | |
1248 | tree lab; | |
1249 | ||
1250 | index = q->index < 0 ? return_index : q->index; | |
1251 | ||
1252 | if (labels[index].q == q) | |
1253 | continue; | |
1254 | ||
1255 | lab = labels[index].label; | |
1256 | ||
1257 | if (index == return_index) | |
1258 | do_return_redirection (q, lab, NULL, &return_val); | |
1259 | else | |
75a70cf9 | 1260 | do_goto_redirection (q, lab, NULL, tf); |
22347b24 | 1261 | } |
e38def9c | 1262 | |
4ee9c684 | 1263 | replace_goto_queue (tf); |
1264 | free (labels); | |
1265 | } | |
1266 | ||
1267 | /* Need to link new stmts after running replace_goto_queue due | |
1268 | to not wanting to process the same goto stmts twice. */ | |
75a70cf9 | 1269 | gimple_seq_add_seq (&tf->top_p_seq, new_stmt); |
4ee9c684 | 1270 | } |
1271 | ||
1272 | /* A subroutine of lower_try_finally. There are multiple edges incoming | |
1273 | and outgoing from the finally block. Implement this by instrumenting | |
1274 | each incoming edge and creating a switch statement at the end of the | |
1275 | finally block that branches to the appropriate destination. */ | |
1276 | ||
1277 | static void | |
1278 | lower_try_finally_switch (struct leh_state *state, struct leh_tf_state *tf) | |
1279 | { | |
1280 | struct goto_queue_node *q, *qe; | |
1281 | tree return_val = NULL; | |
75a70cf9 | 1282 | tree finally_tmp, finally_label; |
4ee9c684 | 1283 | int return_index, eh_index, fallthru_index; |
1284 | int nlabels, ndests, j, last_case_index; | |
75a70cf9 | 1285 | tree last_case; |
1286 | VEC (tree,heap) *case_label_vec; | |
1287 | gimple_seq switch_body; | |
1288 | gimple x; | |
1289 | tree tmp; | |
1290 | gimple switch_stmt; | |
1291 | gimple_seq finally; | |
1292 | struct pointer_map_t *cont_map = NULL; | |
e60a6f7b | 1293 | /* The location of the TRY_FINALLY stmt. */ |
0b35068b | 1294 | location_t tf_loc = gimple_location (tf->try_finally_expr); |
e60a6f7b | 1295 | /* The location of the finally block. */ |
1296 | location_t finally_loc; | |
75a70cf9 | 1297 | |
1298 | switch_body = gimple_seq_alloc (); | |
4ee9c684 | 1299 | |
1300 | /* Mash the TRY block to the head of the chain. */ | |
75a70cf9 | 1301 | finally = gimple_try_cleanup (tf->top_p); |
1302 | tf->top_p_seq = gimple_try_eval (tf->top_p); | |
4ee9c684 | 1303 | |
e60a6f7b | 1304 | /* The location of the finally is either the last stmt in the finally |
1305 | block or the location of the TRY_FINALLY itself. */ | |
1306 | finally_loc = gimple_seq_last_stmt (tf->top_p_seq) != NULL ? | |
1307 | gimple_location (gimple_seq_last_stmt (tf->top_p_seq)) | |
1308 | : tf_loc; | |
1309 | ||
4ee9c684 | 1310 | /* Lower the finally block itself. */ |
75a70cf9 | 1311 | lower_eh_constructs_1 (state, finally); |
4ee9c684 | 1312 | |
1313 | /* Prepare for switch statement generation. */ | |
8cb529a5 | 1314 | nlabels = VEC_length (tree, tf->dest_array); |
4ee9c684 | 1315 | return_index = nlabels; |
1316 | eh_index = return_index + tf->may_return; | |
1317 | fallthru_index = eh_index + tf->may_throw; | |
1318 | ndests = fallthru_index + tf->may_fallthru; | |
1319 | ||
1320 | finally_tmp = create_tmp_var (integer_type_node, "finally_tmp"); | |
e60a6f7b | 1321 | finally_label = create_artificial_label (finally_loc); |
4ee9c684 | 1322 | |
75a70cf9 | 1323 | /* We use VEC_quick_push on case_label_vec throughout this function, |
1324 | since we know the size in advance and allocate precisely as muce | |
1325 | space as needed. */ | |
1326 | case_label_vec = VEC_alloc (tree, heap, ndests); | |
4ee9c684 | 1327 | last_case = NULL; |
1328 | last_case_index = 0; | |
1329 | ||
1330 | /* Begin inserting code for getting to the finally block. Things | |
1331 | are done in this order to correspond to the sequence the code is | |
1332 | layed out. */ | |
1333 | ||
1334 | if (tf->may_fallthru) | |
1335 | { | |
e38def9c | 1336 | x = gimple_build_assign (finally_tmp, |
1337 | build_int_cst (NULL, fallthru_index)); | |
75a70cf9 | 1338 | gimple_seq_add_stmt (&tf->top_p_seq, x); |
4ee9c684 | 1339 | |
40b19772 | 1340 | last_case = build3 (CASE_LABEL_EXPR, void_type_node, |
e38def9c | 1341 | build_int_cst (NULL, fallthru_index), |
1342 | NULL, create_artificial_label (tf_loc)); | |
75a70cf9 | 1343 | VEC_quick_push (tree, case_label_vec, last_case); |
4ee9c684 | 1344 | last_case_index++; |
1345 | ||
75a70cf9 | 1346 | x = gimple_build_label (CASE_LABEL (last_case)); |
1347 | gimple_seq_add_stmt (&switch_body, x); | |
4ee9c684 | 1348 | |
75a70cf9 | 1349 | tmp = lower_try_finally_fallthru_label (tf); |
1350 | x = gimple_build_goto (tmp); | |
1351 | gimple_seq_add_stmt (&switch_body, x); | |
4ee9c684 | 1352 | } |
1353 | ||
1354 | if (tf->may_throw) | |
1355 | { | |
e38def9c | 1356 | emit_post_landing_pad (&eh_seq, tf->region); |
4ee9c684 | 1357 | |
e38def9c | 1358 | x = gimple_build_assign (finally_tmp, |
1359 | build_int_cst (NULL, eh_index)); | |
1360 | gimple_seq_add_stmt (&eh_seq, x); | |
1361 | ||
1362 | x = gimple_build_goto (finally_label); | |
1363 | gimple_seq_add_stmt (&eh_seq, x); | |
4ee9c684 | 1364 | |
40b19772 | 1365 | last_case = build3 (CASE_LABEL_EXPR, void_type_node, |
e38def9c | 1366 | build_int_cst (NULL, eh_index), |
1367 | NULL, create_artificial_label (tf_loc)); | |
75a70cf9 | 1368 | VEC_quick_push (tree, case_label_vec, last_case); |
4ee9c684 | 1369 | last_case_index++; |
1370 | ||
75a70cf9 | 1371 | x = gimple_build_label (CASE_LABEL (last_case)); |
e38def9c | 1372 | gimple_seq_add_stmt (&eh_seq, x); |
1373 | emit_resx (&eh_seq, tf->region); | |
4ee9c684 | 1374 | } |
1375 | ||
75a70cf9 | 1376 | x = gimple_build_label (finally_label); |
1377 | gimple_seq_add_stmt (&tf->top_p_seq, x); | |
4ee9c684 | 1378 | |
75a70cf9 | 1379 | gimple_seq_add_seq (&tf->top_p_seq, finally); |
4ee9c684 | 1380 | |
1381 | /* Redirect each incoming goto edge. */ | |
1382 | q = tf->goto_queue; | |
1383 | qe = q + tf->goto_queue_active; | |
1384 | j = last_case_index + tf->may_return; | |
75a70cf9 | 1385 | /* Prepare the assignments to finally_tmp that are executed upon the |
1386 | entrance through a particular edge. */ | |
4ee9c684 | 1387 | for (; q < qe; ++q) |
1388 | { | |
75a70cf9 | 1389 | gimple_seq mod; |
1390 | int switch_id; | |
1391 | unsigned int case_index; | |
1392 | ||
1393 | mod = gimple_seq_alloc (); | |
4ee9c684 | 1394 | |
1395 | if (q->index < 0) | |
1396 | { | |
75a70cf9 | 1397 | x = gimple_build_assign (finally_tmp, |
e38def9c | 1398 | build_int_cst (NULL, return_index)); |
75a70cf9 | 1399 | gimple_seq_add_stmt (&mod, x); |
4ee9c684 | 1400 | do_return_redirection (q, finally_label, mod, &return_val); |
1401 | switch_id = return_index; | |
1402 | } | |
1403 | else | |
1404 | { | |
75a70cf9 | 1405 | x = gimple_build_assign (finally_tmp, |
e38def9c | 1406 | build_int_cst (NULL, q->index)); |
75a70cf9 | 1407 | gimple_seq_add_stmt (&mod, x); |
1408 | do_goto_redirection (q, finally_label, mod, tf); | |
4ee9c684 | 1409 | switch_id = q->index; |
1410 | } | |
1411 | ||
1412 | case_index = j + q->index; | |
75a70cf9 | 1413 | if (VEC_length (tree, case_label_vec) <= case_index |
1414 | || !VEC_index (tree, case_label_vec, case_index)) | |
1415 | { | |
1416 | tree case_lab; | |
1417 | void **slot; | |
1418 | case_lab = build3 (CASE_LABEL_EXPR, void_type_node, | |
e38def9c | 1419 | build_int_cst (NULL, switch_id), |
1420 | NULL, NULL); | |
75a70cf9 | 1421 | /* We store the cont_stmt in the pointer map, so that we can recover |
1422 | it in the loop below. We don't create the new label while | |
e38def9c | 1423 | walking the goto_queue because pointers don't offer a stable |
75a70cf9 | 1424 | order. */ |
1425 | if (!cont_map) | |
1426 | cont_map = pointer_map_create (); | |
1427 | slot = pointer_map_insert (cont_map, case_lab); | |
1428 | *slot = q->cont_stmt; | |
1429 | VEC_quick_push (tree, case_label_vec, case_lab); | |
1430 | } | |
22347b24 | 1431 | } |
1432 | for (j = last_case_index; j < last_case_index + nlabels; j++) | |
1433 | { | |
1434 | tree label; | |
75a70cf9 | 1435 | gimple cont_stmt; |
1436 | void **slot; | |
22347b24 | 1437 | |
75a70cf9 | 1438 | last_case = VEC_index (tree, case_label_vec, j); |
22347b24 | 1439 | |
1440 | gcc_assert (last_case); | |
75a70cf9 | 1441 | gcc_assert (cont_map); |
22347b24 | 1442 | |
75a70cf9 | 1443 | slot = pointer_map_contains (cont_map, last_case); |
1444 | /* As the comment above suggests, CASE_LABEL (last_case) was just a | |
1445 | placeholder, it does not store an actual label, yet. */ | |
1446 | gcc_assert (slot); | |
1447 | cont_stmt = *(gimple *) slot; | |
22347b24 | 1448 | |
e60a6f7b | 1449 | label = create_artificial_label (tf_loc); |
22347b24 | 1450 | CASE_LABEL (last_case) = label; |
1451 | ||
75a70cf9 | 1452 | x = gimple_build_label (label); |
1453 | gimple_seq_add_stmt (&switch_body, x); | |
1454 | gimple_seq_add_stmt (&switch_body, cont_stmt); | |
22347b24 | 1455 | maybe_record_in_goto_queue (state, cont_stmt); |
4ee9c684 | 1456 | } |
75a70cf9 | 1457 | if (cont_map) |
1458 | pointer_map_destroy (cont_map); | |
1459 | ||
4ee9c684 | 1460 | replace_goto_queue (tf); |
4ee9c684 | 1461 | |
da41aa8e | 1462 | /* Make sure that the last case is the default label, as one is required. |
1463 | Then sort the labels, which is also required in GIMPLE. */ | |
4ee9c684 | 1464 | CASE_LOW (last_case) = NULL; |
da41aa8e | 1465 | sort_case_labels (case_label_vec); |
4ee9c684 | 1466 | |
75a70cf9 | 1467 | /* Build the switch statement, setting last_case to be the default |
1468 | label. */ | |
1469 | switch_stmt = gimple_build_switch_vec (finally_tmp, last_case, | |
1470 | case_label_vec); | |
e60a6f7b | 1471 | gimple_set_location (switch_stmt, finally_loc); |
75a70cf9 | 1472 | |
1473 | /* Need to link SWITCH_STMT after running replace_goto_queue | |
1474 | due to not wanting to process the same goto stmts twice. */ | |
1475 | gimple_seq_add_stmt (&tf->top_p_seq, switch_stmt); | |
1476 | gimple_seq_add_seq (&tf->top_p_seq, switch_body); | |
4ee9c684 | 1477 | } |
1478 | ||
1479 | /* Decide whether or not we are going to duplicate the finally block. | |
1480 | There are several considerations. | |
1481 | ||
1482 | First, if this is Java, then the finally block contains code | |
1483 | written by the user. It has line numbers associated with it, | |
1484 | so duplicating the block means it's difficult to set a breakpoint. | |
1485 | Since controlling code generation via -g is verboten, we simply | |
1486 | never duplicate code without optimization. | |
1487 | ||
1488 | Second, we'd like to prevent egregious code growth. One way to | |
1489 | do this is to estimate the size of the finally block, multiply | |
1490 | that by the number of copies we'd need to make, and compare against | |
1491 | the estimate of the size of the switch machinery we'd have to add. */ | |
1492 | ||
1493 | static bool | |
75a70cf9 | 1494 | decide_copy_try_finally (int ndests, gimple_seq finally) |
4ee9c684 | 1495 | { |
1496 | int f_estimate, sw_estimate; | |
1497 | ||
1498 | if (!optimize) | |
1499 | return false; | |
1500 | ||
1501 | /* Finally estimate N times, plus N gotos. */ | |
75a70cf9 | 1502 | f_estimate = count_insns_seq (finally, &eni_size_weights); |
4ee9c684 | 1503 | f_estimate = (f_estimate + 1) * ndests; |
1504 | ||
1505 | /* Switch statement (cost 10), N variable assignments, N gotos. */ | |
1506 | sw_estimate = 10 + 2 * ndests; | |
1507 | ||
1508 | /* Optimize for size clearly wants our best guess. */ | |
0bfd8d5c | 1509 | if (optimize_function_for_size_p (cfun)) |
4ee9c684 | 1510 | return f_estimate < sw_estimate; |
1511 | ||
1512 | /* ??? These numbers are completely made up so far. */ | |
1513 | if (optimize > 1) | |
72c90b15 | 1514 | return f_estimate < 100 || f_estimate < sw_estimate * 2; |
4ee9c684 | 1515 | else |
72c90b15 | 1516 | return f_estimate < 40 || f_estimate * 2 < sw_estimate * 3; |
4ee9c684 | 1517 | } |
1518 | ||
f340b9ff | 1519 | /* REG is the enclosing region for a possible cleanup region, or the region |
1520 | itself. Returns TRUE if such a region would be unreachable. | |
1521 | ||
1522 | Cleanup regions within a must-not-throw region aren't actually reachable | |
1523 | even if there are throwing stmts within them, because the personality | |
1524 | routine will call terminate before unwinding. */ | |
1525 | ||
1526 | static bool | |
1527 | cleanup_is_dead_in (eh_region reg) | |
1528 | { | |
1529 | while (reg && reg->type == ERT_CLEANUP) | |
1530 | reg = reg->outer; | |
1531 | return (reg && reg->type == ERT_MUST_NOT_THROW); | |
1532 | } | |
75a70cf9 | 1533 | |
1534 | /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_FINALLY nodes | |
4ee9c684 | 1535 | to a sequence of labels and blocks, plus the exception region trees |
ac13e8d9 | 1536 | that record all the magic. This is complicated by the need to |
4ee9c684 | 1537 | arrange for the FINALLY block to be executed on all exits. */ |
1538 | ||
75a70cf9 | 1539 | static gimple_seq |
1540 | lower_try_finally (struct leh_state *state, gimple tp) | |
4ee9c684 | 1541 | { |
1542 | struct leh_tf_state this_tf; | |
1543 | struct leh_state this_state; | |
1544 | int ndests; | |
fa5d8988 | 1545 | gimple_seq old_eh_seq; |
4ee9c684 | 1546 | |
1547 | /* Process the try block. */ | |
1548 | ||
1549 | memset (&this_tf, 0, sizeof (this_tf)); | |
75a70cf9 | 1550 | this_tf.try_finally_expr = tp; |
4ee9c684 | 1551 | this_tf.top_p = tp; |
1552 | this_tf.outer = state; | |
f340b9ff | 1553 | if (using_eh_for_cleanups_p && !cleanup_is_dead_in (state->cur_region)) |
1554 | { | |
1555 | this_tf.region = gen_eh_region_cleanup (state->cur_region); | |
1556 | this_state.cur_region = this_tf.region; | |
1557 | } | |
4ee9c684 | 1558 | else |
f340b9ff | 1559 | { |
1560 | this_tf.region = NULL; | |
1561 | this_state.cur_region = state->cur_region; | |
1562 | } | |
4ee9c684 | 1563 | |
e38def9c | 1564 | this_state.ehp_region = state->ehp_region; |
4ee9c684 | 1565 | this_state.tf = &this_tf; |
1566 | ||
fa5d8988 | 1567 | old_eh_seq = eh_seq; |
1568 | eh_seq = NULL; | |
1569 | ||
75a70cf9 | 1570 | lower_eh_constructs_1 (&this_state, gimple_try_eval(tp)); |
4ee9c684 | 1571 | |
1572 | /* Determine if the try block is escaped through the bottom. */ | |
75a70cf9 | 1573 | this_tf.may_fallthru = gimple_seq_may_fallthru (gimple_try_eval (tp)); |
4ee9c684 | 1574 | |
1575 | /* Determine if any exceptions are possible within the try block. */ | |
f340b9ff | 1576 | if (this_tf.region) |
55d6d4e4 | 1577 | this_tf.may_throw = eh_region_may_contain_throw (this_tf.region); |
4ee9c684 | 1578 | if (this_tf.may_throw) |
e38def9c | 1579 | honor_protect_cleanup_actions (state, &this_state, &this_tf); |
4ee9c684 | 1580 | |
4ee9c684 | 1581 | /* Determine how many edges (still) reach the finally block. Or rather, |
1582 | how many destinations are reached by the finally block. Use this to | |
1583 | determine how we process the finally block itself. */ | |
1584 | ||
8cb529a5 | 1585 | ndests = VEC_length (tree, this_tf.dest_array); |
4ee9c684 | 1586 | ndests += this_tf.may_fallthru; |
1587 | ndests += this_tf.may_return; | |
1588 | ndests += this_tf.may_throw; | |
1589 | ||
1590 | /* If the FINALLY block is not reachable, dike it out. */ | |
1591 | if (ndests == 0) | |
75a70cf9 | 1592 | { |
1593 | gimple_seq_add_seq (&this_tf.top_p_seq, gimple_try_eval (tp)); | |
1594 | gimple_try_set_cleanup (tp, NULL); | |
1595 | } | |
4ee9c684 | 1596 | /* If the finally block doesn't fall through, then any destination |
1597 | we might try to impose there isn't reached either. There may be | |
1598 | some minor amount of cleanup and redirection still needed. */ | |
75a70cf9 | 1599 | else if (!gimple_seq_may_fallthru (gimple_try_cleanup (tp))) |
4ee9c684 | 1600 | lower_try_finally_nofallthru (state, &this_tf); |
1601 | ||
1602 | /* We can easily special-case redirection to a single destination. */ | |
1603 | else if (ndests == 1) | |
1604 | lower_try_finally_onedest (state, &this_tf); | |
75a70cf9 | 1605 | else if (decide_copy_try_finally (ndests, gimple_try_cleanup (tp))) |
4ee9c684 | 1606 | lower_try_finally_copy (state, &this_tf); |
1607 | else | |
1608 | lower_try_finally_switch (state, &this_tf); | |
1609 | ||
1610 | /* If someone requested we add a label at the end of the transformed | |
1611 | block, do so. */ | |
1612 | if (this_tf.fallthru_label) | |
1613 | { | |
75a70cf9 | 1614 | /* This must be reached only if ndests == 0. */ |
1615 | gimple x = gimple_build_label (this_tf.fallthru_label); | |
1616 | gimple_seq_add_stmt (&this_tf.top_p_seq, x); | |
4ee9c684 | 1617 | } |
1618 | ||
8cb529a5 | 1619 | VEC_free (tree, heap, this_tf.dest_array); |
4ee9c684 | 1620 | if (this_tf.goto_queue) |
1621 | free (this_tf.goto_queue); | |
46699809 | 1622 | if (this_tf.goto_queue_map) |
1623 | pointer_map_destroy (this_tf.goto_queue_map); | |
75a70cf9 | 1624 | |
fa5d8988 | 1625 | /* If there was an old (aka outer) eh_seq, append the current eh_seq. |
1626 | If there was no old eh_seq, then the append is trivially already done. */ | |
1627 | if (old_eh_seq) | |
1628 | { | |
1629 | if (eh_seq == NULL) | |
1630 | eh_seq = old_eh_seq; | |
1631 | else | |
1632 | { | |
1633 | gimple_seq new_eh_seq = eh_seq; | |
1634 | eh_seq = old_eh_seq; | |
1635 | gimple_seq_add_seq(&eh_seq, new_eh_seq); | |
1636 | } | |
1637 | } | |
1638 | ||
75a70cf9 | 1639 | return this_tf.top_p_seq; |
4ee9c684 | 1640 | } |
1641 | ||
75a70cf9 | 1642 | /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY_CATCH with a |
1643 | list of GIMPLE_CATCH to a sequence of labels and blocks, plus the | |
1644 | exception region trees that records all the magic. */ | |
4ee9c684 | 1645 | |
75a70cf9 | 1646 | static gimple_seq |
1647 | lower_catch (struct leh_state *state, gimple tp) | |
4ee9c684 | 1648 | { |
55d6d4e4 | 1649 | eh_region try_region = NULL; |
1650 | struct leh_state this_state = *state; | |
75a70cf9 | 1651 | gimple_stmt_iterator gsi; |
4ee9c684 | 1652 | tree out_label; |
e38def9c | 1653 | gimple_seq new_seq; |
1654 | gimple x; | |
e60a6f7b | 1655 | location_t try_catch_loc = gimple_location (tp); |
4ee9c684 | 1656 | |
55d6d4e4 | 1657 | if (flag_exceptions) |
1658 | { | |
1659 | try_region = gen_eh_region_try (state->cur_region); | |
1660 | this_state.cur_region = try_region; | |
1661 | } | |
4ee9c684 | 1662 | |
75a70cf9 | 1663 | lower_eh_constructs_1 (&this_state, gimple_try_eval (tp)); |
4ee9c684 | 1664 | |
55d6d4e4 | 1665 | if (!eh_region_may_contain_throw (try_region)) |
e38def9c | 1666 | return gimple_try_eval (tp); |
1667 | ||
1668 | new_seq = NULL; | |
1669 | emit_eh_dispatch (&new_seq, try_region); | |
1670 | emit_resx (&new_seq, try_region); | |
1671 | ||
1672 | this_state.cur_region = state->cur_region; | |
1673 | this_state.ehp_region = try_region; | |
4ee9c684 | 1674 | |
1675 | out_label = NULL; | |
e38def9c | 1676 | for (gsi = gsi_start (gimple_try_cleanup (tp)); |
1677 | !gsi_end_p (gsi); | |
1678 | gsi_next (&gsi)) | |
4ee9c684 | 1679 | { |
e38def9c | 1680 | eh_catch c; |
1681 | gimple gcatch; | |
1682 | gimple_seq handler; | |
4ee9c684 | 1683 | |
f4e36c33 | 1684 | gcatch = gsi_stmt (gsi); |
e38def9c | 1685 | c = gen_eh_region_catch (try_region, gimple_catch_types (gcatch)); |
4ee9c684 | 1686 | |
e38def9c | 1687 | handler = gimple_catch_handler (gcatch); |
1688 | lower_eh_constructs_1 (&this_state, handler); | |
4ee9c684 | 1689 | |
e38def9c | 1690 | c->label = create_artificial_label (UNKNOWN_LOCATION); |
1691 | x = gimple_build_label (c->label); | |
1692 | gimple_seq_add_stmt (&new_seq, x); | |
4ee9c684 | 1693 | |
e38def9c | 1694 | gimple_seq_add_seq (&new_seq, handler); |
4ee9c684 | 1695 | |
e38def9c | 1696 | if (gimple_seq_may_fallthru (new_seq)) |
4ee9c684 | 1697 | { |
1698 | if (!out_label) | |
e60a6f7b | 1699 | out_label = create_artificial_label (try_catch_loc); |
4ee9c684 | 1700 | |
75a70cf9 | 1701 | x = gimple_build_goto (out_label); |
e38def9c | 1702 | gimple_seq_add_stmt (&new_seq, x); |
4ee9c684 | 1703 | } |
3ded67b5 | 1704 | if (!c->type_list) |
1705 | break; | |
4ee9c684 | 1706 | } |
1707 | ||
e38def9c | 1708 | gimple_try_set_cleanup (tp, new_seq); |
1709 | ||
1710 | return frob_into_branch_around (tp, try_region, out_label); | |
4ee9c684 | 1711 | } |
1712 | ||
75a70cf9 | 1713 | /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with a |
1714 | GIMPLE_EH_FILTER to a sequence of labels and blocks, plus the exception | |
4ee9c684 | 1715 | region trees that record all the magic. */ |
1716 | ||
75a70cf9 | 1717 | static gimple_seq |
1718 | lower_eh_filter (struct leh_state *state, gimple tp) | |
4ee9c684 | 1719 | { |
55d6d4e4 | 1720 | struct leh_state this_state = *state; |
1721 | eh_region this_region = NULL; | |
e38def9c | 1722 | gimple inner, x; |
1723 | gimple_seq new_seq; | |
ac13e8d9 | 1724 | |
75a70cf9 | 1725 | inner = gimple_seq_first_stmt (gimple_try_cleanup (tp)); |
1726 | ||
55d6d4e4 | 1727 | if (flag_exceptions) |
1728 | { | |
1729 | this_region = gen_eh_region_allowed (state->cur_region, | |
1730 | gimple_eh_filter_types (inner)); | |
1731 | this_state.cur_region = this_region; | |
1732 | } | |
ac13e8d9 | 1733 | |
75a70cf9 | 1734 | lower_eh_constructs_1 (&this_state, gimple_try_eval (tp)); |
4ee9c684 | 1735 | |
55d6d4e4 | 1736 | if (!eh_region_may_contain_throw (this_region)) |
e38def9c | 1737 | return gimple_try_eval (tp); |
1738 | ||
1739 | new_seq = NULL; | |
1740 | this_state.cur_region = state->cur_region; | |
1741 | this_state.ehp_region = this_region; | |
1742 | ||
1743 | emit_eh_dispatch (&new_seq, this_region); | |
1744 | emit_resx (&new_seq, this_region); | |
1745 | ||
1746 | this_region->u.allowed.label = create_artificial_label (UNKNOWN_LOCATION); | |
1747 | x = gimple_build_label (this_region->u.allowed.label); | |
1748 | gimple_seq_add_stmt (&new_seq, x); | |
1749 | ||
1750 | lower_eh_constructs_1 (&this_state, gimple_eh_filter_failure (inner)); | |
1751 | gimple_seq_add_seq (&new_seq, gimple_eh_filter_failure (inner)); | |
1752 | ||
1753 | gimple_try_set_cleanup (tp, new_seq); | |
4ee9c684 | 1754 | |
e38def9c | 1755 | return frob_into_branch_around (tp, this_region, NULL); |
1756 | } | |
1757 | ||
1758 | /* A subroutine of lower_eh_constructs_1. Lower a GIMPLE_TRY with | |
1759 | an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks, | |
1760 | plus the exception region trees that record all the magic. */ | |
1761 | ||
1762 | static gimple_seq | |
1763 | lower_eh_must_not_throw (struct leh_state *state, gimple tp) | |
1764 | { | |
55d6d4e4 | 1765 | struct leh_state this_state = *state; |
e38def9c | 1766 | |
55d6d4e4 | 1767 | if (flag_exceptions) |
1768 | { | |
1769 | gimple inner = gimple_seq_first_stmt (gimple_try_cleanup (tp)); | |
1770 | eh_region this_region; | |
e38def9c | 1771 | |
55d6d4e4 | 1772 | this_region = gen_eh_region_must_not_throw (state->cur_region); |
1773 | this_region->u.must_not_throw.failure_decl | |
1774 | = gimple_eh_must_not_throw_fndecl (inner); | |
1775 | this_region->u.must_not_throw.failure_loc = gimple_location (tp); | |
e38def9c | 1776 | |
55d6d4e4 | 1777 | /* In order to get mangling applied to this decl, we must mark it |
1778 | used now. Otherwise, pass_ipa_free_lang_data won't think it | |
1779 | needs to happen. */ | |
1780 | TREE_USED (this_region->u.must_not_throw.failure_decl) = 1; | |
e38def9c | 1781 | |
55d6d4e4 | 1782 | this_state.cur_region = this_region; |
1783 | } | |
4ee9c684 | 1784 | |
e38def9c | 1785 | lower_eh_constructs_1 (&this_state, gimple_try_eval (tp)); |
4ee9c684 | 1786 | |
e38def9c | 1787 | return gimple_try_eval (tp); |
4ee9c684 | 1788 | } |
1789 | ||
1790 | /* Implement a cleanup expression. This is similar to try-finally, | |
1791 | except that we only execute the cleanup block for exception edges. */ | |
1792 | ||
75a70cf9 | 1793 | static gimple_seq |
1794 | lower_cleanup (struct leh_state *state, gimple tp) | |
4ee9c684 | 1795 | { |
55d6d4e4 | 1796 | struct leh_state this_state = *state; |
1797 | eh_region this_region = NULL; | |
4ee9c684 | 1798 | struct leh_tf_state fake_tf; |
75a70cf9 | 1799 | gimple_seq result; |
f340b9ff | 1800 | bool cleanup_dead = cleanup_is_dead_in (state->cur_region); |
4ee9c684 | 1801 | |
f340b9ff | 1802 | if (flag_exceptions && !cleanup_dead) |
4ee9c684 | 1803 | { |
55d6d4e4 | 1804 | this_region = gen_eh_region_cleanup (state->cur_region); |
1805 | this_state.cur_region = this_region; | |
4ee9c684 | 1806 | } |
1807 | ||
75a70cf9 | 1808 | lower_eh_constructs_1 (&this_state, gimple_try_eval (tp)); |
4ee9c684 | 1809 | |
f340b9ff | 1810 | if (cleanup_dead || !eh_region_may_contain_throw (this_region)) |
e38def9c | 1811 | return gimple_try_eval (tp); |
4ee9c684 | 1812 | |
1813 | /* Build enough of a try-finally state so that we can reuse | |
1814 | honor_protect_cleanup_actions. */ | |
1815 | memset (&fake_tf, 0, sizeof (fake_tf)); | |
e60a6f7b | 1816 | fake_tf.top_p = fake_tf.try_finally_expr = tp; |
4ee9c684 | 1817 | fake_tf.outer = state; |
1818 | fake_tf.region = this_region; | |
75a70cf9 | 1819 | fake_tf.may_fallthru = gimple_seq_may_fallthru (gimple_try_eval (tp)); |
4ee9c684 | 1820 | fake_tf.may_throw = true; |
1821 | ||
4ee9c684 | 1822 | honor_protect_cleanup_actions (state, NULL, &fake_tf); |
1823 | ||
1824 | if (fake_tf.may_throw) | |
1825 | { | |
1826 | /* In this case honor_protect_cleanup_actions had nothing to do, | |
1827 | and we should process this normally. */ | |
75a70cf9 | 1828 | lower_eh_constructs_1 (state, gimple_try_cleanup (tp)); |
e38def9c | 1829 | result = frob_into_branch_around (tp, this_region, |
1830 | fake_tf.fallthru_label); | |
4ee9c684 | 1831 | } |
1832 | else | |
1833 | { | |
1834 | /* In this case honor_protect_cleanup_actions did nearly all of | |
1835 | the work. All we have left is to append the fallthru_label. */ | |
1836 | ||
75a70cf9 | 1837 | result = gimple_try_eval (tp); |
4ee9c684 | 1838 | if (fake_tf.fallthru_label) |
1839 | { | |
75a70cf9 | 1840 | gimple x = gimple_build_label (fake_tf.fallthru_label); |
1841 | gimple_seq_add_stmt (&result, x); | |
4ee9c684 | 1842 | } |
1843 | } | |
75a70cf9 | 1844 | return result; |
4ee9c684 | 1845 | } |
1846 | ||
e38def9c | 1847 | /* Main loop for lowering eh constructs. Also moves gsi to the next |
75a70cf9 | 1848 | statement. */ |
4ee9c684 | 1849 | |
1850 | static void | |
75a70cf9 | 1851 | lower_eh_constructs_2 (struct leh_state *state, gimple_stmt_iterator *gsi) |
4ee9c684 | 1852 | { |
75a70cf9 | 1853 | gimple_seq replace; |
1854 | gimple x; | |
1855 | gimple stmt = gsi_stmt (*gsi); | |
4ee9c684 | 1856 | |
75a70cf9 | 1857 | switch (gimple_code (stmt)) |
4ee9c684 | 1858 | { |
75a70cf9 | 1859 | case GIMPLE_CALL: |
e38def9c | 1860 | { |
1861 | tree fndecl = gimple_call_fndecl (stmt); | |
1862 | tree rhs, lhs; | |
1863 | ||
1864 | if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) | |
1865 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1866 | { | |
1867 | case BUILT_IN_EH_POINTER: | |
1868 | /* The front end may have generated a call to | |
1869 | __builtin_eh_pointer (0) within a catch region. Replace | |
1870 | this zero argument with the current catch region number. */ | |
1871 | if (state->ehp_region) | |
1872 | { | |
1873 | tree nr = build_int_cst (NULL, state->ehp_region->index); | |
1874 | gimple_call_set_arg (stmt, 0, nr); | |
1875 | } | |
1876 | else | |
1877 | { | |
1878 | /* The user has dome something silly. Remove it. */ | |
2512209b | 1879 | rhs = null_pointer_node; |
e38def9c | 1880 | goto do_replace; |
1881 | } | |
1882 | break; | |
1883 | ||
1884 | case BUILT_IN_EH_FILTER: | |
1885 | /* ??? This should never appear, but since it's a builtin it | |
1886 | is accessible to abuse by users. Just remove it and | |
1887 | replace the use with the arbitrary value zero. */ | |
1888 | rhs = build_int_cst (TREE_TYPE (TREE_TYPE (fndecl)), 0); | |
1889 | do_replace: | |
1890 | lhs = gimple_call_lhs (stmt); | |
1891 | x = gimple_build_assign (lhs, rhs); | |
1892 | gsi_insert_before (gsi, x, GSI_SAME_STMT); | |
1893 | /* FALLTHRU */ | |
1894 | ||
1895 | case BUILT_IN_EH_COPY_VALUES: | |
1896 | /* Likewise this should not appear. Remove it. */ | |
1897 | gsi_remove (gsi, true); | |
1898 | return; | |
1899 | ||
1900 | default: | |
1901 | break; | |
1902 | } | |
1903 | } | |
1904 | /* FALLTHRU */ | |
1905 | ||
75a70cf9 | 1906 | case GIMPLE_ASSIGN: |
47f11e84 | 1907 | /* If the stmt can throw use a new temporary for the assignment |
1908 | to a LHS. This makes sure the old value of the LHS is | |
fa916956 | 1909 | available on the EH edge. Only do so for statements that |
1910 | potentially fall thru (no noreturn calls e.g.), otherwise | |
1911 | this new assignment might create fake fallthru regions. */ | |
47f11e84 | 1912 | if (stmt_could_throw_p (stmt) |
1913 | && gimple_has_lhs (stmt) | |
fa916956 | 1914 | && gimple_stmt_may_fallthru (stmt) |
47f11e84 | 1915 | && !tree_could_throw_p (gimple_get_lhs (stmt)) |
1916 | && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt)))) | |
1917 | { | |
1918 | tree lhs = gimple_get_lhs (stmt); | |
1919 | tree tmp = create_tmp_var (TREE_TYPE (lhs), NULL); | |
1920 | gimple s = gimple_build_assign (lhs, tmp); | |
1921 | gimple_set_location (s, gimple_location (stmt)); | |
1922 | gimple_set_block (s, gimple_block (stmt)); | |
1923 | gimple_set_lhs (stmt, tmp); | |
1924 | if (TREE_CODE (TREE_TYPE (tmp)) == COMPLEX_TYPE | |
1925 | || TREE_CODE (TREE_TYPE (tmp)) == VECTOR_TYPE) | |
1926 | DECL_GIMPLE_REG_P (tmp) = 1; | |
1927 | gsi_insert_after (gsi, s, GSI_SAME_STMT); | |
1928 | } | |
4ee9c684 | 1929 | /* Look for things that can throw exceptions, and record them. */ |
75a70cf9 | 1930 | if (state->cur_region && stmt_could_throw_p (stmt)) |
4ee9c684 | 1931 | { |
75a70cf9 | 1932 | record_stmt_eh_region (state->cur_region, stmt); |
4ee9c684 | 1933 | note_eh_region_may_contain_throw (state->cur_region); |
4ee9c684 | 1934 | } |
1935 | break; | |
1936 | ||
75a70cf9 | 1937 | case GIMPLE_COND: |
1938 | case GIMPLE_GOTO: | |
1939 | case GIMPLE_RETURN: | |
1940 | maybe_record_in_goto_queue (state, stmt); | |
4ee9c684 | 1941 | break; |
1942 | ||
75a70cf9 | 1943 | case GIMPLE_SWITCH: |
1944 | verify_norecord_switch_expr (state, stmt); | |
4ee9c684 | 1945 | break; |
1946 | ||
75a70cf9 | 1947 | case GIMPLE_TRY: |
1948 | if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY) | |
1949 | replace = lower_try_finally (state, stmt); | |
1950 | else | |
4ee9c684 | 1951 | { |
75a70cf9 | 1952 | x = gimple_seq_first_stmt (gimple_try_cleanup (stmt)); |
c90b5d40 | 1953 | if (!x) |
4ee9c684 | 1954 | { |
c90b5d40 | 1955 | replace = gimple_try_eval (stmt); |
1956 | lower_eh_constructs_1 (state, replace); | |
4ee9c684 | 1957 | } |
c90b5d40 | 1958 | else |
1959 | switch (gimple_code (x)) | |
1960 | { | |
1961 | case GIMPLE_CATCH: | |
1962 | replace = lower_catch (state, stmt); | |
1963 | break; | |
1964 | case GIMPLE_EH_FILTER: | |
1965 | replace = lower_eh_filter (state, stmt); | |
1966 | break; | |
1967 | case GIMPLE_EH_MUST_NOT_THROW: | |
1968 | replace = lower_eh_must_not_throw (state, stmt); | |
1969 | break; | |
1970 | default: | |
1971 | replace = lower_cleanup (state, stmt); | |
1972 | break; | |
1973 | } | |
4ee9c684 | 1974 | } |
75a70cf9 | 1975 | |
1976 | /* Remove the old stmt and insert the transformed sequence | |
1977 | instead. */ | |
1978 | gsi_insert_seq_before (gsi, replace, GSI_SAME_STMT); | |
1979 | gsi_remove (gsi, true); | |
1980 | ||
1981 | /* Return since we don't want gsi_next () */ | |
1982 | return; | |
4ee9c684 | 1983 | |
1984 | default: | |
1985 | /* A type, a decl, or some kind of statement that we're not | |
1986 | interested in. Don't walk them. */ | |
1987 | break; | |
1988 | } | |
75a70cf9 | 1989 | |
1990 | gsi_next (gsi); | |
1991 | } | |
1992 | ||
1993 | /* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */ | |
1994 | ||
1995 | static void | |
1996 | lower_eh_constructs_1 (struct leh_state *state, gimple_seq seq) | |
1997 | { | |
1998 | gimple_stmt_iterator gsi; | |
1999 | for (gsi = gsi_start (seq); !gsi_end_p (gsi);) | |
2000 | lower_eh_constructs_2 (state, &gsi); | |
4ee9c684 | 2001 | } |
2002 | ||
2a1990e9 | 2003 | static unsigned int |
4ee9c684 | 2004 | lower_eh_constructs (void) |
2005 | { | |
2006 | struct leh_state null_state; | |
e38def9c | 2007 | gimple_seq bodyp; |
75a70cf9 | 2008 | |
e38def9c | 2009 | bodyp = gimple_body (current_function_decl); |
2010 | if (bodyp == NULL) | |
2011 | return 0; | |
4ee9c684 | 2012 | |
2013 | finally_tree = htab_create (31, struct_ptr_hash, struct_ptr_eq, free); | |
55d6d4e4 | 2014 | eh_region_may_contain_throw_map = BITMAP_ALLOC (NULL); |
e38def9c | 2015 | memset (&null_state, 0, sizeof (null_state)); |
4ee9c684 | 2016 | |
75a70cf9 | 2017 | collect_finally_tree_1 (bodyp, NULL); |
75a70cf9 | 2018 | lower_eh_constructs_1 (&null_state, bodyp); |
4ee9c684 | 2019 | |
e38def9c | 2020 | /* We assume there's a return statement, or something, at the end of |
2021 | the function, and thus ploping the EH sequence afterward won't | |
2022 | change anything. */ | |
2023 | gcc_assert (!gimple_seq_may_fallthru (bodyp)); | |
2024 | gimple_seq_add_seq (&bodyp, eh_seq); | |
2025 | ||
2026 | /* We assume that since BODYP already existed, adding EH_SEQ to it | |
2027 | didn't change its value, and we don't have to re-set the function. */ | |
2028 | gcc_assert (bodyp == gimple_body (current_function_decl)); | |
4ee9c684 | 2029 | |
e38def9c | 2030 | htab_delete (finally_tree); |
55d6d4e4 | 2031 | BITMAP_FREE (eh_region_may_contain_throw_map); |
e38def9c | 2032 | eh_seq = NULL; |
58d82cd0 | 2033 | |
2034 | /* If this function needs a language specific EH personality routine | |
2035 | and the frontend didn't already set one do so now. */ | |
2036 | if (function_needs_eh_personality (cfun) == eh_personality_lang | |
2037 | && !DECL_FUNCTION_PERSONALITY (current_function_decl)) | |
2038 | DECL_FUNCTION_PERSONALITY (current_function_decl) | |
2039 | = lang_hooks.eh_personality (); | |
2040 | ||
2a1990e9 | 2041 | return 0; |
4ee9c684 | 2042 | } |
2043 | ||
20099e35 | 2044 | struct gimple_opt_pass pass_lower_eh = |
4ee9c684 | 2045 | { |
20099e35 | 2046 | { |
2047 | GIMPLE_PASS, | |
4ee9c684 | 2048 | "eh", /* name */ |
2049 | NULL, /* gate */ | |
2050 | lower_eh_constructs, /* execute */ | |
2051 | NULL, /* sub */ | |
2052 | NULL, /* next */ | |
2053 | 0, /* static_pass_number */ | |
2054 | TV_TREE_EH, /* tv_id */ | |
2055 | PROP_gimple_lcf, /* properties_required */ | |
2056 | PROP_gimple_leh, /* properties_provided */ | |
6354626c | 2057 | 0, /* properties_destroyed */ |
4ee9c684 | 2058 | 0, /* todo_flags_start */ |
20099e35 | 2059 | TODO_dump_func /* todo_flags_finish */ |
2060 | } | |
4ee9c684 | 2061 | }; |
4ee9c684 | 2062 | \f |
e38def9c | 2063 | /* Create the multiple edges from an EH_DISPATCH statement to all of |
2064 | the possible handlers for its EH region. Return true if there's | |
2065 | no fallthru edge; false if there is. */ | |
4ee9c684 | 2066 | |
e38def9c | 2067 | bool |
2068 | make_eh_dispatch_edges (gimple stmt) | |
4ee9c684 | 2069 | { |
e38def9c | 2070 | eh_region r; |
2071 | eh_catch c; | |
4ee9c684 | 2072 | basic_block src, dst; |
2073 | ||
e38def9c | 2074 | r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt)); |
75a70cf9 | 2075 | src = gimple_bb (stmt); |
4ee9c684 | 2076 | |
e38def9c | 2077 | switch (r->type) |
2078 | { | |
2079 | case ERT_TRY: | |
2080 | for (c = r->u.eh_try.first_catch; c ; c = c->next_catch) | |
2081 | { | |
2082 | dst = label_to_block (c->label); | |
2083 | make_edge (src, dst, 0); | |
ac13e8d9 | 2084 | |
e38def9c | 2085 | /* A catch-all handler doesn't have a fallthru. */ |
2086 | if (c->type_list == NULL) | |
2087 | return false; | |
2088 | } | |
2089 | break; | |
a5bfef5b | 2090 | |
e38def9c | 2091 | case ERT_ALLOWED_EXCEPTIONS: |
2092 | dst = label_to_block (r->u.allowed.label); | |
2093 | make_edge (src, dst, 0); | |
2094 | break; | |
2095 | ||
2096 | default: | |
2097 | gcc_unreachable (); | |
2098 | } | |
2099 | ||
2100 | return true; | |
a5bfef5b | 2101 | } |
2102 | ||
e38def9c | 2103 | /* Create the single EH edge from STMT to its nearest landing pad, |
2104 | if there is such a landing pad within the current function. */ | |
2105 | ||
4ee9c684 | 2106 | void |
75a70cf9 | 2107 | make_eh_edges (gimple stmt) |
4ee9c684 | 2108 | { |
e38def9c | 2109 | basic_block src, dst; |
2110 | eh_landing_pad lp; | |
2111 | int lp_nr; | |
4ee9c684 | 2112 | |
e38def9c | 2113 | lp_nr = lookup_stmt_eh_lp (stmt); |
2114 | if (lp_nr <= 0) | |
2115 | return; | |
4ee9c684 | 2116 | |
e38def9c | 2117 | lp = get_eh_landing_pad_from_number (lp_nr); |
2118 | gcc_assert (lp != NULL); | |
d6d5ab2d | 2119 | |
e38def9c | 2120 | src = gimple_bb (stmt); |
2121 | dst = label_to_block (lp->post_landing_pad); | |
2122 | make_edge (src, dst, EDGE_EH); | |
4ee9c684 | 2123 | } |
2124 | ||
e38def9c | 2125 | /* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree; |
2126 | do not actually perform the final edge redirection. | |
927a6b6b | 2127 | |
e38def9c | 2128 | CHANGE_REGION is true when we're being called from cleanup_empty_eh and |
2129 | we intend to change the destination EH region as well; this means | |
2130 | EH_LANDING_PAD_NR must already be set on the destination block label. | |
2131 | If false, we're being called from generic cfg manipulation code and we | |
2132 | should preserve our place within the region tree. */ | |
2133 | ||
2134 | static void | |
2135 | redirect_eh_edge_1 (edge edge_in, basic_block new_bb, bool change_region) | |
927a6b6b | 2136 | { |
e38def9c | 2137 | eh_landing_pad old_lp, new_lp; |
2138 | basic_block old_bb; | |
2139 | gimple throw_stmt; | |
2140 | int old_lp_nr, new_lp_nr; | |
2141 | tree old_label, new_label; | |
2142 | edge_iterator ei; | |
2143 | edge e; | |
2144 | ||
2145 | old_bb = edge_in->dest; | |
2146 | old_label = gimple_block_label (old_bb); | |
2147 | old_lp_nr = EH_LANDING_PAD_NR (old_label); | |
2148 | gcc_assert (old_lp_nr > 0); | |
2149 | old_lp = get_eh_landing_pad_from_number (old_lp_nr); | |
2150 | ||
2151 | throw_stmt = last_stmt (edge_in->src); | |
2152 | gcc_assert (lookup_stmt_eh_lp (throw_stmt) == old_lp_nr); | |
2153 | ||
2154 | new_label = gimple_block_label (new_bb); | |
927a6b6b | 2155 | |
e38def9c | 2156 | /* Look for an existing region that might be using NEW_BB already. */ |
2157 | new_lp_nr = EH_LANDING_PAD_NR (new_label); | |
2158 | if (new_lp_nr) | |
927a6b6b | 2159 | { |
e38def9c | 2160 | new_lp = get_eh_landing_pad_from_number (new_lp_nr); |
2161 | gcc_assert (new_lp); | |
48e1416a | 2162 | |
e38def9c | 2163 | /* Unless CHANGE_REGION is true, the new and old landing pad |
2164 | had better be associated with the same EH region. */ | |
2165 | gcc_assert (change_region || new_lp->region == old_lp->region); | |
927a6b6b | 2166 | } |
2167 | else | |
2168 | { | |
e38def9c | 2169 | new_lp = NULL; |
2170 | gcc_assert (!change_region); | |
927a6b6b | 2171 | } |
2172 | ||
e38def9c | 2173 | /* Notice when we redirect the last EH edge away from OLD_BB. */ |
2174 | FOR_EACH_EDGE (e, ei, old_bb->preds) | |
2175 | if (e != edge_in && (e->flags & EDGE_EH)) | |
2176 | break; | |
b4ba5e9d | 2177 | |
e38def9c | 2178 | if (new_lp) |
b4ba5e9d | 2179 | { |
e38def9c | 2180 | /* NEW_LP already exists. If there are still edges into OLD_LP, |
2181 | there's nothing to do with the EH tree. If there are no more | |
2182 | edges into OLD_LP, then we want to remove OLD_LP as it is unused. | |
2183 | If CHANGE_REGION is true, then our caller is expecting to remove | |
2184 | the landing pad. */ | |
2185 | if (e == NULL && !change_region) | |
2186 | remove_eh_landing_pad (old_lp); | |
b4ba5e9d | 2187 | } |
e38def9c | 2188 | else |
b4ba5e9d | 2189 | { |
e38def9c | 2190 | /* No correct landing pad exists. If there are no more edges |
2191 | into OLD_LP, then we can simply re-use the existing landing pad. | |
2192 | Otherwise, we have to create a new landing pad. */ | |
2193 | if (e == NULL) | |
2194 | { | |
2195 | EH_LANDING_PAD_NR (old_lp->post_landing_pad) = 0; | |
2196 | new_lp = old_lp; | |
2197 | } | |
2198 | else | |
2199 | new_lp = gen_eh_landing_pad (old_lp->region); | |
2200 | new_lp->post_landing_pad = new_label; | |
2201 | EH_LANDING_PAD_NR (new_label) = new_lp->index; | |
b4ba5e9d | 2202 | } |
e38def9c | 2203 | |
2204 | /* Maybe move the throwing statement to the new region. */ | |
2205 | if (old_lp != new_lp) | |
b4ba5e9d | 2206 | { |
e38def9c | 2207 | remove_stmt_from_eh_lp (throw_stmt); |
2208 | add_stmt_to_eh_lp (throw_stmt, new_lp->index); | |
b4ba5e9d | 2209 | } |
b4ba5e9d | 2210 | } |
2211 | ||
e38def9c | 2212 | /* Redirect EH edge E to NEW_BB. */ |
75a70cf9 | 2213 | |
e38def9c | 2214 | edge |
2215 | redirect_eh_edge (edge edge_in, basic_block new_bb) | |
b4ba5e9d | 2216 | { |
e38def9c | 2217 | redirect_eh_edge_1 (edge_in, new_bb, false); |
2218 | return ssa_redirect_edge (edge_in, new_bb); | |
2219 | } | |
b4ba5e9d | 2220 | |
e38def9c | 2221 | /* This is a subroutine of gimple_redirect_edge_and_branch. Update the |
2222 | labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB. | |
2223 | The actual edge update will happen in the caller. */ | |
b4ba5e9d | 2224 | |
e38def9c | 2225 | void |
2226 | redirect_eh_dispatch_edge (gimple stmt, edge e, basic_block new_bb) | |
2227 | { | |
2228 | tree new_lab = gimple_block_label (new_bb); | |
2229 | bool any_changed = false; | |
2230 | basic_block old_bb; | |
2231 | eh_region r; | |
2232 | eh_catch c; | |
2233 | ||
2234 | r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt)); | |
2235 | switch (r->type) | |
b4ba5e9d | 2236 | { |
e38def9c | 2237 | case ERT_TRY: |
2238 | for (c = r->u.eh_try.first_catch; c ; c = c->next_catch) | |
b4ba5e9d | 2239 | { |
e38def9c | 2240 | old_bb = label_to_block (c->label); |
2241 | if (old_bb == e->dest) | |
2242 | { | |
2243 | c->label = new_lab; | |
2244 | any_changed = true; | |
2245 | } | |
b4ba5e9d | 2246 | } |
e38def9c | 2247 | break; |
2248 | ||
2249 | case ERT_ALLOWED_EXCEPTIONS: | |
2250 | old_bb = label_to_block (r->u.allowed.label); | |
2251 | gcc_assert (old_bb == e->dest); | |
2252 | r->u.allowed.label = new_lab; | |
2253 | any_changed = true; | |
2254 | break; | |
2255 | ||
2256 | default: | |
2257 | gcc_unreachable (); | |
b4ba5e9d | 2258 | } |
75a70cf9 | 2259 | |
e38def9c | 2260 | gcc_assert (any_changed); |
b4ba5e9d | 2261 | } |
4ee9c684 | 2262 | \f |
75a70cf9 | 2263 | /* Helper function for operation_could_trap_p and stmt_could_throw_p. */ |
2264 | ||
2ac47fdf | 2265 | bool |
75a70cf9 | 2266 | operation_could_trap_helper_p (enum tree_code op, |
2267 | bool fp_operation, | |
2268 | bool honor_trapv, | |
2269 | bool honor_nans, | |
2270 | bool honor_snans, | |
2271 | tree divisor, | |
2272 | bool *handled) | |
2273 | { | |
2274 | *handled = true; | |
2275 | switch (op) | |
2276 | { | |
2277 | case TRUNC_DIV_EXPR: | |
2278 | case CEIL_DIV_EXPR: | |
2279 | case FLOOR_DIV_EXPR: | |
2280 | case ROUND_DIV_EXPR: | |
2281 | case EXACT_DIV_EXPR: | |
2282 | case CEIL_MOD_EXPR: | |
2283 | case FLOOR_MOD_EXPR: | |
2284 | case ROUND_MOD_EXPR: | |
2285 | case TRUNC_MOD_EXPR: | |
2286 | case RDIV_EXPR: | |
2287 | if (honor_snans || honor_trapv) | |
2288 | return true; | |
2289 | if (fp_operation) | |
2290 | return flag_trapping_math; | |
2291 | if (!TREE_CONSTANT (divisor) || integer_zerop (divisor)) | |
2292 | return true; | |
2293 | return false; | |
2294 | ||
2295 | case LT_EXPR: | |
2296 | case LE_EXPR: | |
2297 | case GT_EXPR: | |
2298 | case GE_EXPR: | |
2299 | case LTGT_EXPR: | |
2300 | /* Some floating point comparisons may trap. */ | |
2301 | return honor_nans; | |
2302 | ||
2303 | case EQ_EXPR: | |
2304 | case NE_EXPR: | |
2305 | case UNORDERED_EXPR: | |
2306 | case ORDERED_EXPR: | |
2307 | case UNLT_EXPR: | |
2308 | case UNLE_EXPR: | |
2309 | case UNGT_EXPR: | |
2310 | case UNGE_EXPR: | |
2311 | case UNEQ_EXPR: | |
2312 | return honor_snans; | |
2313 | ||
2314 | case CONVERT_EXPR: | |
2315 | case FIX_TRUNC_EXPR: | |
2316 | /* Conversion of floating point might trap. */ | |
2317 | return honor_nans; | |
2318 | ||
2319 | case NEGATE_EXPR: | |
2320 | case ABS_EXPR: | |
2321 | case CONJ_EXPR: | |
2322 | /* These operations don't trap with floating point. */ | |
2323 | if (honor_trapv) | |
2324 | return true; | |
2325 | return false; | |
2326 | ||
2327 | case PLUS_EXPR: | |
2328 | case MINUS_EXPR: | |
2329 | case MULT_EXPR: | |
2330 | /* Any floating arithmetic may trap. */ | |
2331 | if (fp_operation && flag_trapping_math) | |
2332 | return true; | |
2333 | if (honor_trapv) | |
2334 | return true; | |
2335 | return false; | |
2336 | ||
aa9d6f35 | 2337 | case COMPLEX_EXPR: |
2338 | case CONSTRUCTOR: | |
2339 | /* Constructing an object cannot trap. */ | |
2340 | return false; | |
2341 | ||
75a70cf9 | 2342 | default: |
2343 | /* Any floating arithmetic may trap. */ | |
2344 | if (fp_operation && flag_trapping_math) | |
2345 | return true; | |
2346 | ||
2347 | *handled = false; | |
2348 | return false; | |
2349 | } | |
2350 | } | |
2351 | ||
2352 | /* Return true if operation OP may trap. FP_OPERATION is true if OP is applied | |
2353 | on floating-point values. HONOR_TRAPV is true if OP is applied on integer | |
2354 | type operands that may trap. If OP is a division operator, DIVISOR contains | |
2355 | the value of the divisor. */ | |
2356 | ||
2357 | bool | |
2358 | operation_could_trap_p (enum tree_code op, bool fp_operation, bool honor_trapv, | |
2359 | tree divisor) | |
2360 | { | |
2361 | bool honor_nans = (fp_operation && flag_trapping_math | |
2362 | && !flag_finite_math_only); | |
2363 | bool honor_snans = fp_operation && flag_signaling_nans != 0; | |
2364 | bool handled; | |
2365 | ||
2366 | if (TREE_CODE_CLASS (op) != tcc_comparison | |
2367 | && TREE_CODE_CLASS (op) != tcc_unary | |
2368 | && TREE_CODE_CLASS (op) != tcc_binary) | |
2369 | return false; | |
2370 | ||
2371 | return operation_could_trap_helper_p (op, fp_operation, honor_trapv, | |
2372 | honor_nans, honor_snans, divisor, | |
2373 | &handled); | |
2374 | } | |
2375 | ||
2376 | /* Return true if EXPR can trap, as in dereferencing an invalid pointer | |
35c15734 | 2377 | location or floating point arithmetic. C.f. the rtl version, may_trap_p. |
2378 | This routine expects only GIMPLE lhs or rhs input. */ | |
4ee9c684 | 2379 | |
2380 | bool | |
2381 | tree_could_trap_p (tree expr) | |
2382 | { | |
75a70cf9 | 2383 | enum tree_code code; |
35c15734 | 2384 | bool fp_operation = false; |
db97ad41 | 2385 | bool honor_trapv = false; |
75a70cf9 | 2386 | tree t, base, div = NULL_TREE; |
4ee9c684 | 2387 | |
75a70cf9 | 2388 | if (!expr) |
2389 | return false; | |
e38def9c | 2390 | |
75a70cf9 | 2391 | code = TREE_CODE (expr); |
2392 | t = TREE_TYPE (expr); | |
2393 | ||
2394 | if (t) | |
35c15734 | 2395 | { |
7076cb5d | 2396 | if (COMPARISON_CLASS_P (expr)) |
2397 | fp_operation = FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0))); | |
2398 | else | |
2399 | fp_operation = FLOAT_TYPE_P (t); | |
75a70cf9 | 2400 | honor_trapv = INTEGRAL_TYPE_P (t) && TYPE_OVERFLOW_TRAPS (t); |
35c15734 | 2401 | } |
2402 | ||
75a70cf9 | 2403 | if (TREE_CODE_CLASS (code) == tcc_binary) |
2404 | div = TREE_OPERAND (expr, 1); | |
2405 | if (operation_could_trap_p (code, fp_operation, honor_trapv, div)) | |
2406 | return true; | |
2407 | ||
80f06481 | 2408 | restart: |
4ee9c684 | 2409 | switch (code) |
2410 | { | |
aed164c3 | 2411 | case TARGET_MEM_REF: |
28daba6f | 2412 | if (TREE_CODE (TMR_BASE (expr)) == ADDR_EXPR |
2413 | && !TMR_INDEX (expr) && !TMR_INDEX2 (expr)) | |
9a14ba4f | 2414 | return false; |
2415 | return !TREE_THIS_NOTRAP (expr); | |
aed164c3 | 2416 | |
4ee9c684 | 2417 | case COMPONENT_REF: |
2418 | case REALPART_EXPR: | |
2419 | case IMAGPART_EXPR: | |
2420 | case BIT_FIELD_REF: | |
26d2ad79 | 2421 | case VIEW_CONVERT_EXPR: |
80f06481 | 2422 | case WITH_SIZE_EXPR: |
2423 | expr = TREE_OPERAND (expr, 0); | |
2424 | code = TREE_CODE (expr); | |
2425 | goto restart; | |
7d23383d | 2426 | |
2427 | case ARRAY_RANGE_REF: | |
2100c228 | 2428 | base = TREE_OPERAND (expr, 0); |
2429 | if (tree_could_trap_p (base)) | |
7d23383d | 2430 | return true; |
2100c228 | 2431 | if (TREE_THIS_NOTRAP (expr)) |
2432 | return false; | |
2100c228 | 2433 | return !range_in_array_bounds_p (expr); |
7d23383d | 2434 | |
2435 | case ARRAY_REF: | |
2436 | base = TREE_OPERAND (expr, 0); | |
7d23383d | 2437 | if (tree_could_trap_p (base)) |
2438 | return true; | |
7d23383d | 2439 | if (TREE_THIS_NOTRAP (expr)) |
2440 | return false; | |
7d23383d | 2441 | return !in_array_bounds_p (expr); |
4ee9c684 | 2442 | |
182cf5a9 | 2443 | case MEM_REF: |
2444 | if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR) | |
2445 | return false; | |
2446 | /* Fallthru. */ | |
4ee9c684 | 2447 | case INDIRECT_REF: |
35c15734 | 2448 | return !TREE_THIS_NOTRAP (expr); |
2449 | ||
2450 | case ASM_EXPR: | |
2451 | return TREE_THIS_VOLATILE (expr); | |
010d0641 | 2452 | |
75a70cf9 | 2453 | case CALL_EXPR: |
2454 | t = get_callee_fndecl (expr); | |
2455 | /* Assume that calls to weak functions may trap. */ | |
2456 | if (!t || !DECL_P (t) || DECL_WEAK (t)) | |
35c15734 | 2457 | return true; |
35c15734 | 2458 | return false; |
2459 | ||
75a70cf9 | 2460 | default: |
2461 | return false; | |
2462 | } | |
2463 | } | |
35c15734 | 2464 | |
35c15734 | 2465 | |
75a70cf9 | 2466 | /* Helper for stmt_could_throw_p. Return true if STMT (assumed to be a |
2467 | an assignment or a conditional) may throw. */ | |
35c15734 | 2468 | |
75a70cf9 | 2469 | static bool |
2470 | stmt_could_throw_1_p (gimple stmt) | |
2471 | { | |
2472 | enum tree_code code = gimple_expr_code (stmt); | |
2473 | bool honor_nans = false; | |
2474 | bool honor_snans = false; | |
2475 | bool fp_operation = false; | |
2476 | bool honor_trapv = false; | |
2477 | tree t; | |
2478 | size_t i; | |
2479 | bool handled, ret; | |
db97ad41 | 2480 | |
75a70cf9 | 2481 | if (TREE_CODE_CLASS (code) == tcc_comparison |
2482 | || TREE_CODE_CLASS (code) == tcc_unary | |
2483 | || TREE_CODE_CLASS (code) == tcc_binary) | |
2484 | { | |
2485 | t = gimple_expr_type (stmt); | |
2486 | fp_operation = FLOAT_TYPE_P (t); | |
2487 | if (fp_operation) | |
2488 | { | |
2489 | honor_nans = flag_trapping_math && !flag_finite_math_only; | |
2490 | honor_snans = flag_signaling_nans != 0; | |
2491 | } | |
2492 | else if (INTEGRAL_TYPE_P (t) && TYPE_OVERFLOW_TRAPS (t)) | |
2493 | honor_trapv = true; | |
2494 | } | |
2495 | ||
2496 | /* Check if the main expression may trap. */ | |
2497 | t = is_gimple_assign (stmt) ? gimple_assign_rhs2 (stmt) : NULL; | |
2498 | ret = operation_could_trap_helper_p (code, fp_operation, honor_trapv, | |
2499 | honor_nans, honor_snans, t, | |
2500 | &handled); | |
2501 | if (handled) | |
2502 | return ret; | |
2503 | ||
2504 | /* If the expression does not trap, see if any of the individual operands may | |
2505 | trap. */ | |
2506 | for (i = 0; i < gimple_num_ops (stmt); i++) | |
2507 | if (tree_could_trap_p (gimple_op (stmt, i))) | |
2508 | return true; | |
2509 | ||
2510 | return false; | |
2511 | } | |
2512 | ||
2513 | ||
2514 | /* Return true if statement STMT could throw an exception. */ | |
2515 | ||
2516 | bool | |
2517 | stmt_could_throw_p (gimple stmt) | |
2518 | { | |
75a70cf9 | 2519 | if (!flag_exceptions) |
2520 | return false; | |
2521 | ||
2522 | /* The only statements that can throw an exception are assignments, | |
e38def9c | 2523 | conditionals, calls, resx, and asms. */ |
2524 | switch (gimple_code (stmt)) | |
2525 | { | |
2526 | case GIMPLE_RESX: | |
2527 | return true; | |
75a70cf9 | 2528 | |
e38def9c | 2529 | case GIMPLE_CALL: |
2530 | return !gimple_call_nothrow_p (stmt); | |
75a70cf9 | 2531 | |
e38def9c | 2532 | case GIMPLE_ASSIGN: |
2533 | case GIMPLE_COND: | |
cbeb677e | 2534 | if (!cfun->can_throw_non_call_exceptions) |
e38def9c | 2535 | return false; |
2536 | return stmt_could_throw_1_p (stmt); | |
75a70cf9 | 2537 | |
e38def9c | 2538 | case GIMPLE_ASM: |
cbeb677e | 2539 | if (!cfun->can_throw_non_call_exceptions) |
e38def9c | 2540 | return false; |
2541 | return gimple_asm_volatile_p (stmt); | |
2542 | ||
2543 | default: | |
2544 | return false; | |
2545 | } | |
4ee9c684 | 2546 | } |
2547 | ||
75a70cf9 | 2548 | |
2549 | /* Return true if expression T could throw an exception. */ | |
2550 | ||
4ee9c684 | 2551 | bool |
2552 | tree_could_throw_p (tree t) | |
2553 | { | |
2554 | if (!flag_exceptions) | |
2555 | return false; | |
75a70cf9 | 2556 | if (TREE_CODE (t) == MODIFY_EXPR) |
4ee9c684 | 2557 | { |
cbeb677e | 2558 | if (cfun->can_throw_non_call_exceptions |
e38def9c | 2559 | && tree_could_trap_p (TREE_OPERAND (t, 0))) |
2560 | return true; | |
75a70cf9 | 2561 | t = TREE_OPERAND (t, 1); |
4ee9c684 | 2562 | } |
2563 | ||
80f06481 | 2564 | if (TREE_CODE (t) == WITH_SIZE_EXPR) |
2565 | t = TREE_OPERAND (t, 0); | |
4ee9c684 | 2566 | if (TREE_CODE (t) == CALL_EXPR) |
2567 | return (call_expr_flags (t) & ECF_NOTHROW) == 0; | |
cbeb677e | 2568 | if (cfun->can_throw_non_call_exceptions) |
3864ad30 | 2569 | return tree_could_trap_p (t); |
4ee9c684 | 2570 | return false; |
2571 | } | |
2572 | ||
b5cebd44 | 2573 | /* Return true if STMT can throw an exception that is not caught within |
2574 | the current function (CFUN). */ | |
2575 | ||
2576 | bool | |
2577 | stmt_can_throw_external (gimple stmt) | |
2578 | { | |
e38def9c | 2579 | int lp_nr; |
b5cebd44 | 2580 | |
2581 | if (!stmt_could_throw_p (stmt)) | |
2582 | return false; | |
2583 | ||
e38def9c | 2584 | lp_nr = lookup_stmt_eh_lp (stmt); |
2585 | return lp_nr == 0; | |
b5cebd44 | 2586 | } |
75a70cf9 | 2587 | |
2588 | /* Return true if STMT can throw an exception that is caught within | |
2589 | the current function (CFUN). */ | |
2590 | ||
4ee9c684 | 2591 | bool |
75a70cf9 | 2592 | stmt_can_throw_internal (gimple stmt) |
4ee9c684 | 2593 | { |
e38def9c | 2594 | int lp_nr; |
75a70cf9 | 2595 | |
e38def9c | 2596 | if (!stmt_could_throw_p (stmt)) |
4ee9c684 | 2597 | return false; |
75a70cf9 | 2598 | |
e38def9c | 2599 | lp_nr = lookup_stmt_eh_lp (stmt); |
2600 | return lp_nr > 0; | |
2601 | } | |
2602 | ||
2603 | /* Given a statement STMT in IFUN, if STMT can no longer throw, then | |
2604 | remove any entry it might have from the EH table. Return true if | |
2605 | any change was made. */ | |
2606 | ||
2607 | bool | |
2608 | maybe_clean_eh_stmt_fn (struct function *ifun, gimple stmt) | |
2609 | { | |
2610 | if (stmt_could_throw_p (stmt)) | |
2611 | return false; | |
2612 | return remove_stmt_from_eh_lp_fn (ifun, stmt); | |
4ee9c684 | 2613 | } |
2614 | ||
e38def9c | 2615 | /* Likewise, but always use the current function. */ |
2616 | ||
2617 | bool | |
2618 | maybe_clean_eh_stmt (gimple stmt) | |
2619 | { | |
2620 | return maybe_clean_eh_stmt_fn (cfun, stmt); | |
2621 | } | |
4ee9c684 | 2622 | |
4c27dd45 | 2623 | /* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced |
2624 | OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT | |
2625 | in the table if it should be in there. Return TRUE if a replacement was | |
2626 | done that my require an EH edge purge. */ | |
2627 | ||
e38def9c | 2628 | bool |
2629 | maybe_clean_or_replace_eh_stmt (gimple old_stmt, gimple new_stmt) | |
35c15734 | 2630 | { |
e38def9c | 2631 | int lp_nr = lookup_stmt_eh_lp (old_stmt); |
4c27dd45 | 2632 | |
e38def9c | 2633 | if (lp_nr != 0) |
4c27dd45 | 2634 | { |
75a70cf9 | 2635 | bool new_stmt_could_throw = stmt_could_throw_p (new_stmt); |
4c27dd45 | 2636 | |
2637 | if (new_stmt == old_stmt && new_stmt_could_throw) | |
2638 | return false; | |
2639 | ||
e38def9c | 2640 | remove_stmt_from_eh_lp (old_stmt); |
4c27dd45 | 2641 | if (new_stmt_could_throw) |
2642 | { | |
e38def9c | 2643 | add_stmt_to_eh_lp (new_stmt, lp_nr); |
4c27dd45 | 2644 | return false; |
2645 | } | |
2646 | else | |
2647 | return true; | |
2648 | } | |
2649 | ||
35c15734 | 2650 | return false; |
2651 | } | |
e38def9c | 2652 | |
2653 | /* Given a statement OLD_STMT in OLD_FUN and a duplicate statment NEW_STMT | |
2654 | in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT. The MAP | |
2655 | operand is the return value of duplicate_eh_regions. */ | |
2656 | ||
2657 | bool | |
2658 | maybe_duplicate_eh_stmt_fn (struct function *new_fun, gimple new_stmt, | |
2659 | struct function *old_fun, gimple old_stmt, | |
2660 | struct pointer_map_t *map, int default_lp_nr) | |
2661 | { | |
2662 | int old_lp_nr, new_lp_nr; | |
2663 | void **slot; | |
2664 | ||
2665 | if (!stmt_could_throw_p (new_stmt)) | |
2666 | return false; | |
2667 | ||
2668 | old_lp_nr = lookup_stmt_eh_lp_fn (old_fun, old_stmt); | |
2669 | if (old_lp_nr == 0) | |
2670 | { | |
2671 | if (default_lp_nr == 0) | |
2672 | return false; | |
2673 | new_lp_nr = default_lp_nr; | |
2674 | } | |
2675 | else if (old_lp_nr > 0) | |
2676 | { | |
2677 | eh_landing_pad old_lp, new_lp; | |
2678 | ||
2679 | old_lp = VEC_index (eh_landing_pad, old_fun->eh->lp_array, old_lp_nr); | |
2680 | slot = pointer_map_contains (map, old_lp); | |
2681 | new_lp = (eh_landing_pad) *slot; | |
2682 | new_lp_nr = new_lp->index; | |
2683 | } | |
2684 | else | |
2685 | { | |
2686 | eh_region old_r, new_r; | |
2687 | ||
2688 | old_r = VEC_index (eh_region, old_fun->eh->region_array, -old_lp_nr); | |
2689 | slot = pointer_map_contains (map, old_r); | |
2690 | new_r = (eh_region) *slot; | |
2691 | new_lp_nr = -new_r->index; | |
2692 | } | |
2693 | ||
2694 | add_stmt_to_eh_lp_fn (new_fun, new_stmt, new_lp_nr); | |
2695 | return true; | |
2696 | } | |
2697 | ||
2698 | /* Similar, but both OLD_STMT and NEW_STMT are within the current function, | |
2699 | and thus no remapping is required. */ | |
2700 | ||
2701 | bool | |
2702 | maybe_duplicate_eh_stmt (gimple new_stmt, gimple old_stmt) | |
2703 | { | |
2704 | int lp_nr; | |
2705 | ||
2706 | if (!stmt_could_throw_p (new_stmt)) | |
2707 | return false; | |
2708 | ||
2709 | lp_nr = lookup_stmt_eh_lp (old_stmt); | |
2710 | if (lp_nr == 0) | |
2711 | return false; | |
2712 | ||
2713 | add_stmt_to_eh_lp (new_stmt, lp_nr); | |
2714 | return true; | |
2715 | } | |
4888ab9a | 2716 | \f |
75a70cf9 | 2717 | /* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of |
2718 | GIMPLE_TRY) that are similar enough to be considered the same. Currently | |
2719 | this only handles handlers consisting of a single call, as that's the | |
2720 | important case for C++: a destructor call for a particular object showing | |
2721 | up in multiple handlers. */ | |
4888ab9a | 2722 | |
2723 | static bool | |
75a70cf9 | 2724 | same_handler_p (gimple_seq oneh, gimple_seq twoh) |
4888ab9a | 2725 | { |
75a70cf9 | 2726 | gimple_stmt_iterator gsi; |
2727 | gimple ones, twos; | |
2728 | unsigned int ai; | |
4888ab9a | 2729 | |
75a70cf9 | 2730 | gsi = gsi_start (oneh); |
2731 | if (!gsi_one_before_end_p (gsi)) | |
4888ab9a | 2732 | return false; |
75a70cf9 | 2733 | ones = gsi_stmt (gsi); |
4888ab9a | 2734 | |
75a70cf9 | 2735 | gsi = gsi_start (twoh); |
2736 | if (!gsi_one_before_end_p (gsi)) | |
4888ab9a | 2737 | return false; |
75a70cf9 | 2738 | twos = gsi_stmt (gsi); |
2739 | ||
2740 | if (!is_gimple_call (ones) | |
2741 | || !is_gimple_call (twos) | |
2742 | || gimple_call_lhs (ones) | |
2743 | || gimple_call_lhs (twos) | |
2744 | || gimple_call_chain (ones) | |
2745 | || gimple_call_chain (twos) | |
fb049fba | 2746 | || !gimple_call_same_target_p (ones, twos) |
75a70cf9 | 2747 | || gimple_call_num_args (ones) != gimple_call_num_args (twos)) |
4888ab9a | 2748 | return false; |
2749 | ||
75a70cf9 | 2750 | for (ai = 0; ai < gimple_call_num_args (ones); ++ai) |
2751 | if (!operand_equal_p (gimple_call_arg (ones, ai), | |
e38def9c | 2752 | gimple_call_arg (twos, ai), 0)) |
4888ab9a | 2753 | return false; |
2754 | ||
2755 | return true; | |
2756 | } | |
2757 | ||
2758 | /* Optimize | |
2759 | try { A() } finally { try { ~B() } catch { ~A() } } | |
2760 | try { ... } finally { ~A() } | |
2761 | into | |
2762 | try { A() } catch { ~B() } | |
2763 | try { ~B() ... } finally { ~A() } | |
2764 | ||
2765 | This occurs frequently in C++, where A is a local variable and B is a | |
2766 | temporary used in the initializer for A. */ | |
2767 | ||
2768 | static void | |
75a70cf9 | 2769 | optimize_double_finally (gimple one, gimple two) |
4888ab9a | 2770 | { |
75a70cf9 | 2771 | gimple oneh; |
2772 | gimple_stmt_iterator gsi; | |
4888ab9a | 2773 | |
75a70cf9 | 2774 | gsi = gsi_start (gimple_try_cleanup (one)); |
2775 | if (!gsi_one_before_end_p (gsi)) | |
4888ab9a | 2776 | return; |
2777 | ||
75a70cf9 | 2778 | oneh = gsi_stmt (gsi); |
2779 | if (gimple_code (oneh) != GIMPLE_TRY | |
2780 | || gimple_try_kind (oneh) != GIMPLE_TRY_CATCH) | |
4888ab9a | 2781 | return; |
2782 | ||
75a70cf9 | 2783 | if (same_handler_p (gimple_try_cleanup (oneh), gimple_try_cleanup (two))) |
4888ab9a | 2784 | { |
75a70cf9 | 2785 | gimple_seq seq = gimple_try_eval (oneh); |
4888ab9a | 2786 | |
75a70cf9 | 2787 | gimple_try_set_cleanup (one, seq); |
2788 | gimple_try_set_kind (one, GIMPLE_TRY_CATCH); | |
2789 | seq = copy_gimple_seq_and_replace_locals (seq); | |
2790 | gimple_seq_add_seq (&seq, gimple_try_eval (two)); | |
2791 | gimple_try_set_eval (two, seq); | |
4888ab9a | 2792 | } |
2793 | } | |
2794 | ||
2795 | /* Perform EH refactoring optimizations that are simpler to do when code | |
c7684b8e | 2796 | flow has been lowered but EH structures haven't. */ |
4888ab9a | 2797 | |
2798 | static void | |
75a70cf9 | 2799 | refactor_eh_r (gimple_seq seq) |
4888ab9a | 2800 | { |
75a70cf9 | 2801 | gimple_stmt_iterator gsi; |
2802 | gimple one, two; | |
4888ab9a | 2803 | |
75a70cf9 | 2804 | one = NULL; |
2805 | two = NULL; | |
2806 | gsi = gsi_start (seq); | |
2807 | while (1) | |
2808 | { | |
2809 | one = two; | |
2810 | if (gsi_end_p (gsi)) | |
2811 | two = NULL; | |
2812 | else | |
2813 | two = gsi_stmt (gsi); | |
2814 | if (one | |
2815 | && two | |
2816 | && gimple_code (one) == GIMPLE_TRY | |
2817 | && gimple_code (two) == GIMPLE_TRY | |
2818 | && gimple_try_kind (one) == GIMPLE_TRY_FINALLY | |
2819 | && gimple_try_kind (two) == GIMPLE_TRY_FINALLY) | |
2820 | optimize_double_finally (one, two); | |
2821 | if (one) | |
2822 | switch (gimple_code (one)) | |
4888ab9a | 2823 | { |
75a70cf9 | 2824 | case GIMPLE_TRY: |
2825 | refactor_eh_r (gimple_try_eval (one)); | |
2826 | refactor_eh_r (gimple_try_cleanup (one)); | |
2827 | break; | |
2828 | case GIMPLE_CATCH: | |
2829 | refactor_eh_r (gimple_catch_handler (one)); | |
2830 | break; | |
2831 | case GIMPLE_EH_FILTER: | |
2832 | refactor_eh_r (gimple_eh_filter_failure (one)); | |
2833 | break; | |
2834 | default: | |
2835 | break; | |
4888ab9a | 2836 | } |
75a70cf9 | 2837 | if (two) |
2838 | gsi_next (&gsi); | |
2839 | else | |
2840 | break; | |
4888ab9a | 2841 | } |
2842 | } | |
2843 | ||
2844 | static unsigned | |
2845 | refactor_eh (void) | |
2846 | { | |
75a70cf9 | 2847 | refactor_eh_r (gimple_body (current_function_decl)); |
4888ab9a | 2848 | return 0; |
2849 | } | |
2850 | ||
e38def9c | 2851 | static bool |
2852 | gate_refactor_eh (void) | |
2853 | { | |
2854 | return flag_exceptions != 0; | |
2855 | } | |
2856 | ||
20099e35 | 2857 | struct gimple_opt_pass pass_refactor_eh = |
4888ab9a | 2858 | { |
20099e35 | 2859 | { |
2860 | GIMPLE_PASS, | |
4888ab9a | 2861 | "ehopt", /* name */ |
e38def9c | 2862 | gate_refactor_eh, /* gate */ |
4888ab9a | 2863 | refactor_eh, /* execute */ |
2864 | NULL, /* sub */ | |
2865 | NULL, /* next */ | |
2866 | 0, /* static_pass_number */ | |
2867 | TV_TREE_EH, /* tv_id */ | |
2868 | PROP_gimple_lcf, /* properties_required */ | |
2869 | 0, /* properties_provided */ | |
2870 | 0, /* properties_destroyed */ | |
2871 | 0, /* todo_flags_start */ | |
20099e35 | 2872 | TODO_dump_func /* todo_flags_finish */ |
2873 | } | |
4888ab9a | 2874 | }; |
e38def9c | 2875 | \f |
2876 | /* At the end of gimple optimization, we can lower RESX. */ | |
4c5fcca6 | 2877 | |
e38def9c | 2878 | static bool |
2879 | lower_resx (basic_block bb, gimple stmt, struct pointer_map_t *mnt_map) | |
4c5fcca6 | 2880 | { |
e38def9c | 2881 | int lp_nr; |
2882 | eh_region src_r, dst_r; | |
2883 | gimple_stmt_iterator gsi; | |
2884 | gimple x; | |
2885 | tree fn, src_nr; | |
2886 | bool ret = false; | |
4c5fcca6 | 2887 | |
e38def9c | 2888 | lp_nr = lookup_stmt_eh_lp (stmt); |
2889 | if (lp_nr != 0) | |
2890 | dst_r = get_eh_region_from_lp_number (lp_nr); | |
2891 | else | |
2892 | dst_r = NULL; | |
4c5fcca6 | 2893 | |
e38def9c | 2894 | src_r = get_eh_region_from_number (gimple_resx_region (stmt)); |
e38def9c | 2895 | gsi = gsi_last_bb (bb); |
4c5fcca6 | 2896 | |
395fc2bb | 2897 | if (src_r == NULL) |
2898 | { | |
2899 | /* We can wind up with no source region when pass_cleanup_eh shows | |
2900 | that there are no entries into an eh region and deletes it, but | |
2901 | then the block that contains the resx isn't removed. This can | |
2902 | happen without optimization when the switch statement created by | |
2903 | lower_try_finally_switch isn't simplified to remove the eh case. | |
2904 | ||
2905 | Resolve this by expanding the resx node to an abort. */ | |
2906 | ||
2907 | fn = implicit_built_in_decls[BUILT_IN_TRAP]; | |
2908 | x = gimple_build_call (fn, 0); | |
2909 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
2910 | ||
2911 | while (EDGE_COUNT (bb->succs) > 0) | |
2912 | remove_edge (EDGE_SUCC (bb, 0)); | |
2913 | } | |
2914 | else if (dst_r) | |
e38def9c | 2915 | { |
2916 | /* When we have a destination region, we resolve this by copying | |
2917 | the excptr and filter values into place, and changing the edge | |
2918 | to immediately after the landing pad. */ | |
2919 | edge e; | |
4c5fcca6 | 2920 | |
e38def9c | 2921 | if (lp_nr < 0) |
2922 | { | |
2923 | basic_block new_bb; | |
2924 | void **slot; | |
2925 | tree lab; | |
3d1eacdb | 2926 | |
e38def9c | 2927 | /* We are resuming into a MUST_NOT_CALL region. Expand a call to |
2928 | the failure decl into a new block, if needed. */ | |
2929 | gcc_assert (dst_r->type == ERT_MUST_NOT_THROW); | |
4c5fcca6 | 2930 | |
e38def9c | 2931 | slot = pointer_map_contains (mnt_map, dst_r); |
2932 | if (slot == NULL) | |
2933 | { | |
2934 | gimple_stmt_iterator gsi2; | |
4c5fcca6 | 2935 | |
e38def9c | 2936 | new_bb = create_empty_bb (bb); |
2937 | lab = gimple_block_label (new_bb); | |
2938 | gsi2 = gsi_start_bb (new_bb); | |
4c5fcca6 | 2939 | |
e38def9c | 2940 | fn = dst_r->u.must_not_throw.failure_decl; |
2941 | x = gimple_build_call (fn, 0); | |
2942 | gimple_set_location (x, dst_r->u.must_not_throw.failure_loc); | |
2943 | gsi_insert_after (&gsi2, x, GSI_CONTINUE_LINKING); | |
3bd82487 | 2944 | |
e38def9c | 2945 | slot = pointer_map_insert (mnt_map, dst_r); |
2946 | *slot = lab; | |
2947 | } | |
2948 | else | |
2949 | { | |
2950 | lab = (tree) *slot; | |
2951 | new_bb = label_to_block (lab); | |
2952 | } | |
4c5fcca6 | 2953 | |
e38def9c | 2954 | gcc_assert (EDGE_COUNT (bb->succs) == 0); |
2955 | e = make_edge (bb, new_bb, EDGE_FALLTHRU); | |
2956 | e->count = bb->count; | |
2957 | e->probability = REG_BR_PROB_BASE; | |
2958 | } | |
2959 | else | |
2960 | { | |
2961 | edge_iterator ei; | |
2962 | tree dst_nr = build_int_cst (NULL, dst_r->index); | |
4c5fcca6 | 2963 | |
e38def9c | 2964 | fn = implicit_built_in_decls[BUILT_IN_EH_COPY_VALUES]; |
395fc2bb | 2965 | src_nr = build_int_cst (NULL, src_r->index); |
e38def9c | 2966 | x = gimple_build_call (fn, 2, dst_nr, src_nr); |
2967 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
4c5fcca6 | 2968 | |
e38def9c | 2969 | /* Update the flags for the outgoing edge. */ |
2970 | e = single_succ_edge (bb); | |
2971 | gcc_assert (e->flags & EDGE_EH); | |
2972 | e->flags = (e->flags & ~EDGE_EH) | EDGE_FALLTHRU; | |
4c5fcca6 | 2973 | |
e38def9c | 2974 | /* If there are no more EH users of the landing pad, delete it. */ |
2975 | FOR_EACH_EDGE (e, ei, e->dest->preds) | |
2976 | if (e->flags & EDGE_EH) | |
2977 | break; | |
2978 | if (e == NULL) | |
2979 | { | |
2980 | eh_landing_pad lp = get_eh_landing_pad_from_number (lp_nr); | |
2981 | remove_eh_landing_pad (lp); | |
2982 | } | |
2983 | } | |
4c5fcca6 | 2984 | |
e38def9c | 2985 | ret = true; |
2986 | } | |
2987 | else | |
2988 | { | |
2989 | tree var; | |
4c5fcca6 | 2990 | |
e38def9c | 2991 | /* When we don't have a destination region, this exception escapes |
2992 | up the call chain. We resolve this by generating a call to the | |
2993 | _Unwind_Resume library function. */ | |
4c5fcca6 | 2994 | |
471eff36 | 2995 | /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup |
e38def9c | 2996 | with no arguments for C++ and Java. Check for that. */ |
471eff36 | 2997 | if (src_r->use_cxa_end_cleanup) |
2998 | { | |
2999 | fn = implicit_built_in_decls[BUILT_IN_CXA_END_CLEANUP]; | |
3000 | x = gimple_build_call (fn, 0); | |
3001 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3002 | } | |
3003 | else | |
3bd82487 | 3004 | { |
e38def9c | 3005 | fn = implicit_built_in_decls[BUILT_IN_EH_POINTER]; |
395fc2bb | 3006 | src_nr = build_int_cst (NULL, src_r->index); |
e38def9c | 3007 | x = gimple_build_call (fn, 1, src_nr); |
3008 | var = create_tmp_var (ptr_type_node, NULL); | |
3009 | var = make_ssa_name (var, x); | |
3010 | gimple_call_set_lhs (x, var); | |
3011 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3012 | ||
3013 | fn = implicit_built_in_decls[BUILT_IN_UNWIND_RESUME]; | |
3014 | x = gimple_build_call (fn, 1, var); | |
3015 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3bd82487 | 3016 | } |
4c5fcca6 | 3017 | |
e38def9c | 3018 | gcc_assert (EDGE_COUNT (bb->succs) == 0); |
3bd82487 | 3019 | } |
3d1eacdb | 3020 | |
e38def9c | 3021 | gsi_remove (&gsi, true); |
3022 | ||
3023 | return ret; | |
3bd82487 | 3024 | } |
3025 | ||
e38def9c | 3026 | static unsigned |
3027 | execute_lower_resx (void) | |
3028 | { | |
3029 | basic_block bb; | |
3030 | struct pointer_map_t *mnt_map; | |
3031 | bool dominance_invalidated = false; | |
3032 | bool any_rewritten = false; | |
3bd82487 | 3033 | |
e38def9c | 3034 | mnt_map = pointer_map_create (); |
3bd82487 | 3035 | |
e38def9c | 3036 | FOR_EACH_BB (bb) |
3037 | { | |
3038 | gimple last = last_stmt (bb); | |
3039 | if (last && is_gimple_resx (last)) | |
3040 | { | |
3041 | dominance_invalidated |= lower_resx (bb, last, mnt_map); | |
3042 | any_rewritten = true; | |
3043 | } | |
3044 | } | |
3045 | ||
3046 | pointer_map_destroy (mnt_map); | |
3047 | ||
3048 | if (dominance_invalidated) | |
3049 | { | |
3050 | free_dominance_info (CDI_DOMINATORS); | |
3051 | free_dominance_info (CDI_POST_DOMINATORS); | |
3bd82487 | 3052 | } |
4c5fcca6 | 3053 | |
e38def9c | 3054 | return any_rewritten ? TODO_update_ssa_only_virtuals : 0; |
3055 | } | |
4c5fcca6 | 3056 | |
e38def9c | 3057 | static bool |
395fc2bb | 3058 | gate_lower_resx (void) |
e38def9c | 3059 | { |
395fc2bb | 3060 | return flag_exceptions != 0; |
e38def9c | 3061 | } |
3bd82487 | 3062 | |
e38def9c | 3063 | struct gimple_opt_pass pass_lower_resx = |
3bd82487 | 3064 | { |
e38def9c | 3065 | { |
3066 | GIMPLE_PASS, | |
3067 | "resx", /* name */ | |
395fc2bb | 3068 | gate_lower_resx, /* gate */ |
e38def9c | 3069 | execute_lower_resx, /* execute */ |
3070 | NULL, /* sub */ | |
3071 | NULL, /* next */ | |
3072 | 0, /* static_pass_number */ | |
3073 | TV_TREE_EH, /* tv_id */ | |
3074 | PROP_gimple_lcf, /* properties_required */ | |
3075 | 0, /* properties_provided */ | |
3076 | 0, /* properties_destroyed */ | |
3077 | 0, /* todo_flags_start */ | |
3078 | TODO_dump_func | TODO_verify_flow /* todo_flags_finish */ | |
3079 | } | |
3bd82487 | 3080 | }; |
3081 | ||
e38def9c | 3082 | |
778f5bdd | 3083 | /* At the end of inlining, we can lower EH_DISPATCH. Return true when |
3084 | we have found some duplicate labels and removed some edges. */ | |
3bd82487 | 3085 | |
778f5bdd | 3086 | static bool |
e38def9c | 3087 | lower_eh_dispatch (basic_block src, gimple stmt) |
3bd82487 | 3088 | { |
e38def9c | 3089 | gimple_stmt_iterator gsi; |
3090 | int region_nr; | |
3091 | eh_region r; | |
3092 | tree filter, fn; | |
3093 | gimple x; | |
778f5bdd | 3094 | bool redirected = false; |
3bd82487 | 3095 | |
e38def9c | 3096 | region_nr = gimple_eh_dispatch_region (stmt); |
3097 | r = get_eh_region_from_number (region_nr); | |
3bd82487 | 3098 | |
e38def9c | 3099 | gsi = gsi_last_bb (src); |
3bd82487 | 3100 | |
e38def9c | 3101 | switch (r->type) |
3bd82487 | 3102 | { |
e38def9c | 3103 | case ERT_TRY: |
3104 | { | |
3105 | VEC (tree, heap) *labels = NULL; | |
3106 | tree default_label = NULL; | |
3107 | eh_catch c; | |
3108 | edge_iterator ei; | |
3109 | edge e; | |
778f5bdd | 3110 | struct pointer_set_t *seen_values = pointer_set_create (); |
e38def9c | 3111 | |
3112 | /* Collect the labels for a switch. Zero the post_landing_pad | |
3113 | field becase we'll no longer have anything keeping these labels | |
3114 | in existance and the optimizer will be free to merge these | |
3115 | blocks at will. */ | |
3116 | for (c = r->u.eh_try.first_catch; c ; c = c->next_catch) | |
3117 | { | |
3118 | tree tp_node, flt_node, lab = c->label; | |
778f5bdd | 3119 | bool have_label = false; |
3bd82487 | 3120 | |
e38def9c | 3121 | c->label = NULL; |
3122 | tp_node = c->type_list; | |
3123 | flt_node = c->filter_list; | |
3124 | ||
3125 | if (tp_node == NULL) | |
3126 | { | |
3127 | default_label = lab; | |
3128 | break; | |
3129 | } | |
3130 | do | |
3131 | { | |
778f5bdd | 3132 | /* Filter out duplicate labels that arise when this handler |
3133 | is shadowed by an earlier one. When no labels are | |
3134 | attached to the handler anymore, we remove | |
3135 | the corresponding edge and then we delete unreachable | |
3136 | blocks at the end of this pass. */ | |
3137 | if (! pointer_set_contains (seen_values, TREE_VALUE (flt_node))) | |
3138 | { | |
3139 | tree t = build3 (CASE_LABEL_EXPR, void_type_node, | |
3140 | TREE_VALUE (flt_node), NULL, lab); | |
3141 | VEC_safe_push (tree, heap, labels, t); | |
3142 | pointer_set_insert (seen_values, TREE_VALUE (flt_node)); | |
3143 | have_label = true; | |
3144 | } | |
e38def9c | 3145 | |
3146 | tp_node = TREE_CHAIN (tp_node); | |
3147 | flt_node = TREE_CHAIN (flt_node); | |
3148 | } | |
3149 | while (tp_node); | |
778f5bdd | 3150 | if (! have_label) |
3151 | { | |
3152 | remove_edge (find_edge (src, label_to_block (lab))); | |
3153 | redirected = true; | |
3154 | } | |
e38def9c | 3155 | } |
3156 | ||
3157 | /* Clean up the edge flags. */ | |
3158 | FOR_EACH_EDGE (e, ei, src->succs) | |
3159 | { | |
3160 | if (e->flags & EDGE_FALLTHRU) | |
3161 | { | |
3162 | /* If there was no catch-all, use the fallthru edge. */ | |
3163 | if (default_label == NULL) | |
3164 | default_label = gimple_block_label (e->dest); | |
3165 | e->flags &= ~EDGE_FALLTHRU; | |
3166 | } | |
3167 | } | |
3168 | gcc_assert (default_label != NULL); | |
3169 | ||
3170 | /* Don't generate a switch if there's only a default case. | |
3171 | This is common in the form of try { A; } catch (...) { B; }. */ | |
3172 | if (labels == NULL) | |
3173 | { | |
3174 | e = single_succ_edge (src); | |
3175 | e->flags |= EDGE_FALLTHRU; | |
3176 | } | |
3177 | else | |
3178 | { | |
3179 | fn = implicit_built_in_decls[BUILT_IN_EH_FILTER]; | |
3180 | x = gimple_build_call (fn, 1, build_int_cst (NULL, region_nr)); | |
3181 | filter = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL); | |
3182 | filter = make_ssa_name (filter, x); | |
3183 | gimple_call_set_lhs (x, filter); | |
3184 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3185 | ||
3186 | /* Turn the default label into a default case. */ | |
3187 | default_label = build3 (CASE_LABEL_EXPR, void_type_node, | |
3188 | NULL, NULL, default_label); | |
3189 | sort_case_labels (labels); | |
3190 | ||
3191 | x = gimple_build_switch_vec (filter, default_label, labels); | |
3192 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3193 | ||
3194 | VEC_free (tree, heap, labels); | |
3195 | } | |
778f5bdd | 3196 | pointer_set_destroy (seen_values); |
e38def9c | 3197 | } |
3198 | break; | |
3199 | ||
3200 | case ERT_ALLOWED_EXCEPTIONS: | |
3201 | { | |
3202 | edge b_e = BRANCH_EDGE (src); | |
3203 | edge f_e = FALLTHRU_EDGE (src); | |
3204 | ||
3205 | fn = implicit_built_in_decls[BUILT_IN_EH_FILTER]; | |
3206 | x = gimple_build_call (fn, 1, build_int_cst (NULL, region_nr)); | |
3207 | filter = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL); | |
3208 | filter = make_ssa_name (filter, x); | |
3209 | gimple_call_set_lhs (x, filter); | |
3210 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3211 | ||
3212 | r->u.allowed.label = NULL; | |
3213 | x = gimple_build_cond (EQ_EXPR, filter, | |
3214 | build_int_cst (TREE_TYPE (filter), | |
3215 | r->u.allowed.filter), | |
3216 | NULL_TREE, NULL_TREE); | |
3217 | gsi_insert_before (&gsi, x, GSI_SAME_STMT); | |
3218 | ||
3219 | b_e->flags = b_e->flags | EDGE_TRUE_VALUE; | |
3220 | f_e->flags = (f_e->flags & ~EDGE_FALLTHRU) | EDGE_FALSE_VALUE; | |
3221 | } | |
3222 | break; | |
3223 | ||
3224 | default: | |
3225 | gcc_unreachable (); | |
3bd82487 | 3226 | } |
e38def9c | 3227 | |
3228 | /* Replace the EH_DISPATCH with the SWITCH or COND generated above. */ | |
3229 | gsi_remove (&gsi, true); | |
778f5bdd | 3230 | return redirected; |
3bd82487 | 3231 | } |
3232 | ||
e38def9c | 3233 | static unsigned |
3234 | execute_lower_eh_dispatch (void) | |
3235 | { | |
3236 | basic_block bb; | |
3237 | bool any_rewritten = false; | |
778f5bdd | 3238 | bool redirected = false; |
3bd82487 | 3239 | |
e38def9c | 3240 | assign_filter_values (); |
3d1eacdb | 3241 | |
e38def9c | 3242 | FOR_EACH_BB (bb) |
3243 | { | |
3244 | gimple last = last_stmt (bb); | |
3245 | if (last && gimple_code (last) == GIMPLE_EH_DISPATCH) | |
3246 | { | |
778f5bdd | 3247 | redirected |= lower_eh_dispatch (bb, last); |
e38def9c | 3248 | any_rewritten = true; |
3249 | } | |
3250 | } | |
3251 | ||
778f5bdd | 3252 | if (redirected) |
3253 | delete_unreachable_blocks (); | |
e38def9c | 3254 | return any_rewritten ? TODO_update_ssa_only_virtuals : 0; |
3255 | } | |
3256 | ||
395fc2bb | 3257 | static bool |
3258 | gate_lower_eh_dispatch (void) | |
3259 | { | |
3260 | return cfun->eh->region_tree != NULL; | |
3261 | } | |
3262 | ||
e38def9c | 3263 | struct gimple_opt_pass pass_lower_eh_dispatch = |
3bd82487 | 3264 | { |
e38def9c | 3265 | { |
3266 | GIMPLE_PASS, | |
3267 | "ehdisp", /* name */ | |
395fc2bb | 3268 | gate_lower_eh_dispatch, /* gate */ |
e38def9c | 3269 | execute_lower_eh_dispatch, /* execute */ |
3270 | NULL, /* sub */ | |
3271 | NULL, /* next */ | |
3272 | 0, /* static_pass_number */ | |
3273 | TV_TREE_EH, /* tv_id */ | |
3274 | PROP_gimple_lcf, /* properties_required */ | |
3275 | 0, /* properties_provided */ | |
3276 | 0, /* properties_destroyed */ | |
3277 | 0, /* todo_flags_start */ | |
3278 | TODO_dump_func | TODO_verify_flow /* todo_flags_finish */ | |
3279 | } | |
3280 | }; | |
3281 | \f | |
3282 | /* Walk statements, see what regions are really referenced and remove | |
3283 | those that are unused. */ | |
3284 | ||
3285 | static void | |
3286 | remove_unreachable_handlers (void) | |
3287 | { | |
3288 | sbitmap r_reachable, lp_reachable; | |
3289 | eh_region region; | |
3290 | eh_landing_pad lp; | |
3291 | basic_block bb; | |
3292 | int lp_nr, r_nr; | |
3bd82487 | 3293 | |
e38def9c | 3294 | r_reachable = sbitmap_alloc (VEC_length (eh_region, cfun->eh->region_array)); |
3295 | lp_reachable | |
3296 | = sbitmap_alloc (VEC_length (eh_landing_pad, cfun->eh->lp_array)); | |
3297 | sbitmap_zero (r_reachable); | |
3298 | sbitmap_zero (lp_reachable); | |
3bd82487 | 3299 | |
e38def9c | 3300 | FOR_EACH_BB (bb) |
3bd82487 | 3301 | { |
e38def9c | 3302 | gimple_stmt_iterator gsi = gsi_start_bb (bb); |
3303 | ||
3304 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
3305 | { | |
3306 | gimple stmt = gsi_stmt (gsi); | |
3307 | lp_nr = lookup_stmt_eh_lp (stmt); | |
3308 | ||
3309 | /* Negative LP numbers are MUST_NOT_THROW regions which | |
3310 | are not considered BB enders. */ | |
3311 | if (lp_nr < 0) | |
3312 | SET_BIT (r_reachable, -lp_nr); | |
3313 | ||
3314 | /* Positive LP numbers are real landing pads, are are BB enders. */ | |
3315 | else if (lp_nr > 0) | |
3316 | { | |
3317 | gcc_assert (gsi_one_before_end_p (gsi)); | |
3318 | region = get_eh_region_from_lp_number (lp_nr); | |
3319 | SET_BIT (r_reachable, region->index); | |
3320 | SET_BIT (lp_reachable, lp_nr); | |
3321 | } | |
3322 | } | |
3bd82487 | 3323 | } |
e38def9c | 3324 | |
3325 | if (dump_file) | |
3bd82487 | 3326 | { |
e38def9c | 3327 | fprintf (dump_file, "Before removal of unreachable regions:\n"); |
3328 | dump_eh_tree (dump_file, cfun); | |
3329 | fprintf (dump_file, "Reachable regions: "); | |
3330 | dump_sbitmap_file (dump_file, r_reachable); | |
3331 | fprintf (dump_file, "Reachable landing pads: "); | |
3332 | dump_sbitmap_file (dump_file, lp_reachable); | |
3bd82487 | 3333 | } |
3334 | ||
e38def9c | 3335 | for (r_nr = 1; |
3336 | VEC_iterate (eh_region, cfun->eh->region_array, r_nr, region); ++r_nr) | |
3337 | if (region && !TEST_BIT (r_reachable, r_nr)) | |
3338 | { | |
3339 | if (dump_file) | |
3340 | fprintf (dump_file, "Removing unreachable region %d\n", r_nr); | |
3341 | remove_eh_handler (region); | |
3342 | } | |
3bd82487 | 3343 | |
e38def9c | 3344 | for (lp_nr = 1; |
3345 | VEC_iterate (eh_landing_pad, cfun->eh->lp_array, lp_nr, lp); ++lp_nr) | |
3346 | if (lp && !TEST_BIT (lp_reachable, lp_nr)) | |
3347 | { | |
3348 | if (dump_file) | |
3349 | fprintf (dump_file, "Removing unreachable landing pad %d\n", lp_nr); | |
3350 | remove_eh_landing_pad (lp); | |
3351 | } | |
48e1416a | 3352 | |
e38def9c | 3353 | if (dump_file) |
3bd82487 | 3354 | { |
e38def9c | 3355 | fprintf (dump_file, "\n\nAfter removal of unreachable regions:\n"); |
3356 | dump_eh_tree (dump_file, cfun); | |
3357 | fprintf (dump_file, "\n\n"); | |
3bd82487 | 3358 | } |
3359 | ||
e38def9c | 3360 | sbitmap_free (r_reachable); |
3361 | sbitmap_free (lp_reachable); | |
3362 | ||
3363 | #ifdef ENABLE_CHECKING | |
3364 | verify_eh_tree (cfun); | |
3365 | #endif | |
3366 | } | |
3367 | ||
3368 | /* Remove regions that do not have landing pads. This assumes | |
3369 | that remove_unreachable_handlers has already been run, and | |
3370 | that we've just manipulated the landing pads since then. */ | |
3371 | ||
3372 | static void | |
3373 | remove_unreachable_handlers_no_lp (void) | |
3374 | { | |
3375 | eh_region r; | |
3376 | int i; | |
3377 | ||
3378 | for (i = 1; VEC_iterate (eh_region, cfun->eh->region_array, i, r); ++i) | |
3379 | if (r && r->landing_pads == NULL && r->type != ERT_MUST_NOT_THROW) | |
3380 | { | |
3381 | if (dump_file) | |
3382 | fprintf (dump_file, "Removing unreachable region %d\n", i); | |
3383 | remove_eh_handler (r); | |
3384 | } | |
3bd82487 | 3385 | } |
3386 | ||
e38def9c | 3387 | /* Undo critical edge splitting on an EH landing pad. Earlier, we |
3388 | optimisticaly split all sorts of edges, including EH edges. The | |
3389 | optimization passes in between may not have needed them; if not, | |
3390 | we should undo the split. | |
3391 | ||
3392 | Recognize this case by having one EH edge incoming to the BB and | |
3393 | one normal edge outgoing; BB should be empty apart from the | |
3394 | post_landing_pad label. | |
3395 | ||
3396 | Note that this is slightly different from the empty handler case | |
3397 | handled by cleanup_empty_eh, in that the actual handler may yet | |
3398 | have actual code but the landing pad has been separated from the | |
3399 | handler. As such, cleanup_empty_eh relies on this transformation | |
3400 | having been done first. */ | |
4c5fcca6 | 3401 | |
3402 | static bool | |
e38def9c | 3403 | unsplit_eh (eh_landing_pad lp) |
4c5fcca6 | 3404 | { |
e38def9c | 3405 | basic_block bb = label_to_block (lp->post_landing_pad); |
3406 | gimple_stmt_iterator gsi; | |
3407 | edge e_in, e_out; | |
3408 | ||
3409 | /* Quickly check the edge counts on BB for singularity. */ | |
3410 | if (EDGE_COUNT (bb->preds) != 1 || EDGE_COUNT (bb->succs) != 1) | |
3411 | return false; | |
3412 | e_in = EDGE_PRED (bb, 0); | |
3413 | e_out = EDGE_SUCC (bb, 0); | |
4c5fcca6 | 3414 | |
e38def9c | 3415 | /* Input edge must be EH and output edge must be normal. */ |
3416 | if ((e_in->flags & EDGE_EH) == 0 || (e_out->flags & EDGE_EH) != 0) | |
3417 | return false; | |
3418 | ||
0b76e49c | 3419 | /* The block must be empty except for the labels and debug insns. */ |
3420 | gsi = gsi_after_labels (bb); | |
3421 | if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi))) | |
3422 | gsi_next_nondebug (&gsi); | |
3423 | if (!gsi_end_p (gsi)) | |
e38def9c | 3424 | return false; |
3425 | ||
3426 | /* The destination block must not already have a landing pad | |
3427 | for a different region. */ | |
3428 | for (gsi = gsi_start_bb (e_out->dest); !gsi_end_p (gsi); gsi_next (&gsi)) | |
4c5fcca6 | 3429 | { |
e38def9c | 3430 | gimple stmt = gsi_stmt (gsi); |
3431 | tree lab; | |
3432 | int lp_nr; | |
4c5fcca6 | 3433 | |
e38def9c | 3434 | if (gimple_code (stmt) != GIMPLE_LABEL) |
3435 | break; | |
3436 | lab = gimple_label_label (stmt); | |
3437 | lp_nr = EH_LANDING_PAD_NR (lab); | |
3438 | if (lp_nr && get_eh_region_from_lp_number (lp_nr) != lp->region) | |
3439 | return false; | |
3440 | } | |
4c5fcca6 | 3441 | |
e9d5f86f | 3442 | /* The new destination block must not already be a destination of |
3443 | the source block, lest we merge fallthru and eh edges and get | |
3444 | all sorts of confused. */ | |
3445 | if (find_edge (e_in->src, e_out->dest)) | |
3446 | return false; | |
3447 | ||
c57e3b9d | 3448 | /* ??? We can get degenerate phis due to cfg cleanups. I would have |
3449 | thought this should have been cleaned up by a phicprop pass, but | |
3450 | that doesn't appear to handle virtuals. Propagate by hand. */ | |
3451 | if (!gimple_seq_empty_p (phi_nodes (bb))) | |
3452 | { | |
3453 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); ) | |
3454 | { | |
3455 | gimple use_stmt, phi = gsi_stmt (gsi); | |
3456 | tree lhs = gimple_phi_result (phi); | |
3457 | tree rhs = gimple_phi_arg_def (phi, 0); | |
3458 | use_operand_p use_p; | |
3459 | imm_use_iterator iter; | |
3460 | ||
3461 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) | |
3462 | { | |
3463 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
3464 | SET_USE (use_p, rhs); | |
3465 | } | |
3466 | ||
3467 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
3468 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1; | |
3469 | ||
3470 | remove_phi_node (&gsi, true); | |
3471 | } | |
3472 | } | |
3d1eacdb | 3473 | |
e38def9c | 3474 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3475 | fprintf (dump_file, "Unsplit EH landing pad %d to block %i.\n", | |
3476 | lp->index, e_out->dest->index); | |
3477 | ||
3478 | /* Redirect the edge. Since redirect_eh_edge_1 expects to be moving | |
3479 | a successor edge, humor it. But do the real CFG change with the | |
3480 | predecessor of E_OUT in order to preserve the ordering of arguments | |
3481 | to the PHI nodes in E_OUT->DEST. */ | |
3482 | redirect_eh_edge_1 (e_in, e_out->dest, false); | |
3483 | redirect_edge_pred (e_out, e_in->src); | |
3484 | e_out->flags = e_in->flags; | |
3485 | e_out->probability = e_in->probability; | |
3486 | e_out->count = e_in->count; | |
3487 | remove_edge (e_in); | |
3d1eacdb | 3488 | |
e38def9c | 3489 | return true; |
3490 | } | |
3d1eacdb | 3491 | |
e38def9c | 3492 | /* Examine each landing pad block and see if it matches unsplit_eh. */ |
3d1eacdb | 3493 | |
e38def9c | 3494 | static bool |
3495 | unsplit_all_eh (void) | |
3496 | { | |
3497 | bool changed = false; | |
3498 | eh_landing_pad lp; | |
3499 | int i; | |
3d1eacdb | 3500 | |
e38def9c | 3501 | for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i) |
3502 | if (lp) | |
3503 | changed |= unsplit_eh (lp); | |
3504 | ||
3505 | return changed; | |
3506 | } | |
3507 | ||
3508 | /* A subroutine of cleanup_empty_eh. Redirect all EH edges incoming | |
3509 | to OLD_BB to NEW_BB; return true on success, false on failure. | |
3510 | ||
3511 | OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any | |
3512 | PHI variables from OLD_BB we can pick them up from OLD_BB_OUT. | |
3513 | Virtual PHIs may be deleted and marked for renaming. */ | |
3514 | ||
3515 | static bool | |
3516 | cleanup_empty_eh_merge_phis (basic_block new_bb, basic_block old_bb, | |
c57e3b9d | 3517 | edge old_bb_out, bool change_region) |
e38def9c | 3518 | { |
3519 | gimple_stmt_iterator ngsi, ogsi; | |
3520 | edge_iterator ei; | |
3521 | edge e; | |
3522 | bitmap rename_virts; | |
3523 | bitmap ophi_handled; | |
3524 | ||
3525 | FOR_EACH_EDGE (e, ei, old_bb->preds) | |
3526 | redirect_edge_var_map_clear (e); | |
3527 | ||
3528 | ophi_handled = BITMAP_ALLOC (NULL); | |
3529 | rename_virts = BITMAP_ALLOC (NULL); | |
3530 | ||
3531 | /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map | |
3532 | for the edges we're going to move. */ | |
3533 | for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); gsi_next (&ngsi)) | |
3534 | { | |
3535 | gimple ophi, nphi = gsi_stmt (ngsi); | |
3536 | tree nresult, nop; | |
3537 | ||
3538 | nresult = gimple_phi_result (nphi); | |
3539 | nop = gimple_phi_arg_def (nphi, old_bb_out->dest_idx); | |
3540 | ||
3541 | /* Find the corresponding PHI in OLD_BB so we can forward-propagate | |
3542 | the source ssa_name. */ | |
3543 | ophi = NULL; | |
3544 | for (ogsi = gsi_start_phis (old_bb); !gsi_end_p (ogsi); gsi_next (&ogsi)) | |
3545 | { | |
3546 | ophi = gsi_stmt (ogsi); | |
3547 | if (gimple_phi_result (ophi) == nop) | |
3548 | break; | |
3549 | ophi = NULL; | |
927a6b6b | 3550 | } |
3d1eacdb | 3551 | |
e38def9c | 3552 | /* If we did find the corresponding PHI, copy those inputs. */ |
3553 | if (ophi) | |
4c5fcca6 | 3554 | { |
6e21b2e0 | 3555 | /* If NOP is used somewhere else beyond phis in new_bb, give up. */ |
3556 | if (!has_single_use (nop)) | |
3557 | { | |
3558 | imm_use_iterator imm_iter; | |
3559 | use_operand_p use_p; | |
3560 | ||
3561 | FOR_EACH_IMM_USE_FAST (use_p, imm_iter, nop) | |
3562 | { | |
3563 | if (!gimple_debug_bind_p (USE_STMT (use_p)) | |
3564 | && (gimple_code (USE_STMT (use_p)) != GIMPLE_PHI | |
3565 | || gimple_bb (USE_STMT (use_p)) != new_bb)) | |
3566 | goto fail; | |
3567 | } | |
3568 | } | |
e38def9c | 3569 | bitmap_set_bit (ophi_handled, SSA_NAME_VERSION (nop)); |
3570 | FOR_EACH_EDGE (e, ei, old_bb->preds) | |
3d1eacdb | 3571 | { |
e38def9c | 3572 | location_t oloc; |
3573 | tree oop; | |
3574 | ||
3575 | if ((e->flags & EDGE_EH) == 0) | |
3576 | continue; | |
3577 | oop = gimple_phi_arg_def (ophi, e->dest_idx); | |
3578 | oloc = gimple_phi_arg_location (ophi, e->dest_idx); | |
3579 | redirect_edge_var_map_add (e, nresult, oop, oloc); | |
3d1eacdb | 3580 | } |
e38def9c | 3581 | } |
3582 | /* If we didn't find the PHI, but it's a VOP, remember to rename | |
3583 | it later, assuming all other tests succeed. */ | |
3584 | else if (!is_gimple_reg (nresult)) | |
3585 | bitmap_set_bit (rename_virts, SSA_NAME_VERSION (nresult)); | |
3586 | /* If we didn't find the PHI, and it's a real variable, we know | |
3587 | from the fact that OLD_BB is tree_empty_eh_handler_p that the | |
3588 | variable is unchanged from input to the block and we can simply | |
3589 | re-use the input to NEW_BB from the OLD_BB_OUT edge. */ | |
3590 | else | |
3591 | { | |
3592 | location_t nloc | |
3593 | = gimple_phi_arg_location (nphi, old_bb_out->dest_idx); | |
3594 | FOR_EACH_EDGE (e, ei, old_bb->preds) | |
3595 | redirect_edge_var_map_add (e, nresult, nop, nloc); | |
3596 | } | |
3597 | } | |
3598 | ||
3599 | /* Second, verify that all PHIs from OLD_BB have been handled. If not, | |
3600 | we don't know what values from the other edges into NEW_BB to use. */ | |
3601 | for (ogsi = gsi_start_phis (old_bb); !gsi_end_p (ogsi); gsi_next (&ogsi)) | |
3602 | { | |
3603 | gimple ophi = gsi_stmt (ogsi); | |
3604 | tree oresult = gimple_phi_result (ophi); | |
3605 | if (!bitmap_bit_p (ophi_handled, SSA_NAME_VERSION (oresult))) | |
3606 | goto fail; | |
3607 | } | |
3608 | ||
3609 | /* At this point we know that the merge will succeed. Remove the PHI | |
3610 | nodes for the virtuals that we want to rename. */ | |
3611 | if (!bitmap_empty_p (rename_virts)) | |
3612 | { | |
3613 | for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); ) | |
3614 | { | |
3615 | gimple nphi = gsi_stmt (ngsi); | |
3616 | tree nresult = gimple_phi_result (nphi); | |
3617 | if (bitmap_bit_p (rename_virts, SSA_NAME_VERSION (nresult))) | |
3d1eacdb | 3618 | { |
e38def9c | 3619 | mark_virtual_phi_result_for_renaming (nphi); |
3620 | remove_phi_node (&ngsi, true); | |
3d1eacdb | 3621 | } |
3622 | else | |
e38def9c | 3623 | gsi_next (&ngsi); |
3bd82487 | 3624 | } |
e38def9c | 3625 | } |
3bd82487 | 3626 | |
e38def9c | 3627 | /* Finally, move the edges and update the PHIs. */ |
3628 | for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)); ) | |
3629 | if (e->flags & EDGE_EH) | |
3630 | { | |
c57e3b9d | 3631 | redirect_eh_edge_1 (e, new_bb, change_region); |
e38def9c | 3632 | redirect_edge_succ (e, new_bb); |
3633 | flush_pending_stmts (e); | |
3634 | } | |
3635 | else | |
3636 | ei_next (&ei); | |
3bd82487 | 3637 | |
e38def9c | 3638 | BITMAP_FREE (ophi_handled); |
3639 | BITMAP_FREE (rename_virts); | |
3640 | return true; | |
3641 | ||
3642 | fail: | |
3643 | FOR_EACH_EDGE (e, ei, old_bb->preds) | |
3644 | redirect_edge_var_map_clear (e); | |
3645 | BITMAP_FREE (ophi_handled); | |
3646 | BITMAP_FREE (rename_virts); | |
3647 | return false; | |
3648 | } | |
3649 | ||
3650 | /* A subroutine of cleanup_empty_eh. Move a landing pad LP from its | |
3651 | old region to NEW_REGION at BB. */ | |
3652 | ||
3653 | static void | |
3654 | cleanup_empty_eh_move_lp (basic_block bb, edge e_out, | |
3655 | eh_landing_pad lp, eh_region new_region) | |
3656 | { | |
3657 | gimple_stmt_iterator gsi; | |
3658 | eh_landing_pad *pp; | |
3659 | ||
3660 | for (pp = &lp->region->landing_pads; *pp != lp; pp = &(*pp)->next_lp) | |
3661 | continue; | |
3662 | *pp = lp->next_lp; | |
3663 | ||
3664 | lp->region = new_region; | |
3665 | lp->next_lp = new_region->landing_pads; | |
3666 | new_region->landing_pads = lp; | |
3667 | ||
3668 | /* Delete the RESX that was matched within the empty handler block. */ | |
3669 | gsi = gsi_last_bb (bb); | |
3670 | mark_virtual_ops_for_renaming (gsi_stmt (gsi)); | |
3671 | gsi_remove (&gsi, true); | |
3672 | ||
3673 | /* Clean up E_OUT for the fallthru. */ | |
3674 | e_out->flags = (e_out->flags & ~EDGE_EH) | EDGE_FALLTHRU; | |
3675 | e_out->probability = REG_BR_PROB_BASE; | |
3676 | } | |
3677 | ||
3678 | /* A subroutine of cleanup_empty_eh. Handle more complex cases of | |
48e1416a | 3679 | unsplitting than unsplit_eh was prepared to handle, e.g. when |
e38def9c | 3680 | multiple incoming edges and phis are involved. */ |
3681 | ||
3682 | static bool | |
c57e3b9d | 3683 | cleanup_empty_eh_unsplit (basic_block bb, edge e_out, eh_landing_pad lp) |
e38def9c | 3684 | { |
3685 | gimple_stmt_iterator gsi; | |
e38def9c | 3686 | tree lab; |
8cbab433 | 3687 | edge_iterator ei; |
3688 | edge e; | |
e38def9c | 3689 | |
3690 | /* We really ought not have totally lost everything following | |
3691 | a landing pad label. Given that BB is empty, there had better | |
3692 | be a successor. */ | |
3693 | gcc_assert (e_out != NULL); | |
3694 | ||
c57e3b9d | 3695 | /* The destination block must not already have a landing pad |
3696 | for a different region. */ | |
e38def9c | 3697 | lab = NULL; |
3698 | for (gsi = gsi_start_bb (e_out->dest); !gsi_end_p (gsi); gsi_next (&gsi)) | |
3699 | { | |
3700 | gimple stmt = gsi_stmt (gsi); | |
c57e3b9d | 3701 | int lp_nr; |
3702 | ||
e38def9c | 3703 | if (gimple_code (stmt) != GIMPLE_LABEL) |
3704 | break; | |
3705 | lab = gimple_label_label (stmt); | |
c57e3b9d | 3706 | lp_nr = EH_LANDING_PAD_NR (lab); |
3707 | if (lp_nr && get_eh_region_from_lp_number (lp_nr) != lp->region) | |
3708 | return false; | |
e38def9c | 3709 | } |
e38def9c | 3710 | |
8cbab433 | 3711 | /* The destination block must not be a regular successor for any |
3712 | of the preds of the landing pad. Thus, avoid turning | |
3713 | <..> | |
3714 | | \ EH | |
3715 | | <..> | |
3716 | | / | |
3717 | <..> | |
3718 | into | |
3719 | <..> | |
3720 | | | EH | |
3721 | <..> | |
3722 | which CFG verification would choke on. See PR45172. */ | |
3723 | FOR_EACH_EDGE (e, ei, bb->preds) | |
3724 | if (find_edge (e->src, e_out->dest)) | |
3725 | return false; | |
3726 | ||
e38def9c | 3727 | /* Attempt to move the PHIs into the successor block. */ |
c57e3b9d | 3728 | if (cleanup_empty_eh_merge_phis (e_out->dest, bb, e_out, false)) |
e38def9c | 3729 | { |
3730 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3731 | fprintf (dump_file, | |
c57e3b9d | 3732 | "Unsplit EH landing pad %d to block %i " |
3733 | "(via cleanup_empty_eh).\n", | |
3734 | lp->index, e_out->dest->index); | |
e38def9c | 3735 | return true; |
3736 | } | |
3737 | ||
3738 | return false; | |
3739 | } | |
3740 | ||
a9309f85 | 3741 | /* Return true if edge E_FIRST is part of an empty infinite loop |
3742 | or leads to such a loop through a series of single successor | |
3743 | empty bbs. */ | |
3744 | ||
3745 | static bool | |
3746 | infinite_empty_loop_p (edge e_first) | |
3747 | { | |
3748 | bool inf_loop = false; | |
3749 | edge e; | |
3750 | ||
3751 | if (e_first->dest == e_first->src) | |
3752 | return true; | |
3753 | ||
3754 | e_first->src->aux = (void *) 1; | |
3755 | for (e = e_first; single_succ_p (e->dest); e = single_succ_edge (e->dest)) | |
3756 | { | |
3757 | gimple_stmt_iterator gsi; | |
3758 | if (e->dest->aux) | |
3759 | { | |
3760 | inf_loop = true; | |
3761 | break; | |
3762 | } | |
3763 | e->dest->aux = (void *) 1; | |
3764 | gsi = gsi_after_labels (e->dest); | |
3765 | if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi))) | |
3766 | gsi_next_nondebug (&gsi); | |
3767 | if (!gsi_end_p (gsi)) | |
3768 | break; | |
3769 | } | |
3770 | e_first->src->aux = NULL; | |
3771 | for (e = e_first; e->dest->aux; e = single_succ_edge (e->dest)) | |
3772 | e->dest->aux = NULL; | |
3773 | ||
3774 | return inf_loop; | |
3775 | } | |
3776 | ||
e38def9c | 3777 | /* Examine the block associated with LP to determine if it's an empty |
3778 | handler for its EH region. If so, attempt to redirect EH edges to | |
3779 | an outer region. Return true the CFG was updated in any way. This | |
3780 | is similar to jump forwarding, just across EH edges. */ | |
3781 | ||
3782 | static bool | |
3783 | cleanup_empty_eh (eh_landing_pad lp) | |
3784 | { | |
3785 | basic_block bb = label_to_block (lp->post_landing_pad); | |
3786 | gimple_stmt_iterator gsi; | |
3787 | gimple resx; | |
3788 | eh_region new_region; | |
3789 | edge_iterator ei; | |
3790 | edge e, e_out; | |
3791 | bool has_non_eh_pred; | |
3792 | int new_lp_nr; | |
3793 | ||
3794 | /* There can be zero or one edges out of BB. This is the quickest test. */ | |
3795 | switch (EDGE_COUNT (bb->succs)) | |
3796 | { | |
3797 | case 0: | |
3798 | e_out = NULL; | |
3799 | break; | |
3800 | case 1: | |
3801 | e_out = EDGE_SUCC (bb, 0); | |
3802 | break; | |
3803 | default: | |
3804 | return false; | |
3805 | } | |
3806 | gsi = gsi_after_labels (bb); | |
3807 | ||
3808 | /* Make sure to skip debug statements. */ | |
3809 | if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi))) | |
3810 | gsi_next_nondebug (&gsi); | |
3811 | ||
3812 | /* If the block is totally empty, look for more unsplitting cases. */ | |
3813 | if (gsi_end_p (gsi)) | |
e54fce5c | 3814 | { |
3815 | /* For the degenerate case of an infinite loop bail out. */ | |
a9309f85 | 3816 | if (infinite_empty_loop_p (e_out)) |
e54fce5c | 3817 | return false; |
3818 | ||
3819 | return cleanup_empty_eh_unsplit (bb, e_out, lp); | |
3820 | } | |
e38def9c | 3821 | |
3822 | /* The block should consist only of a single RESX statement. */ | |
3823 | resx = gsi_stmt (gsi); | |
3824 | if (!is_gimple_resx (resx)) | |
3825 | return false; | |
3826 | gcc_assert (gsi_one_before_end_p (gsi)); | |
3827 | ||
3828 | /* Determine if there are non-EH edges, or resx edges into the handler. */ | |
3829 | has_non_eh_pred = false; | |
3830 | FOR_EACH_EDGE (e, ei, bb->preds) | |
3831 | if (!(e->flags & EDGE_EH)) | |
3832 | has_non_eh_pred = true; | |
3833 | ||
3834 | /* Find the handler that's outer of the empty handler by looking at | |
3835 | where the RESX instruction was vectored. */ | |
3836 | new_lp_nr = lookup_stmt_eh_lp (resx); | |
3837 | new_region = get_eh_region_from_lp_number (new_lp_nr); | |
3838 | ||
3839 | /* If there's no destination region within the current function, | |
3840 | redirection is trivial via removing the throwing statements from | |
3841 | the EH region, removing the EH edges, and allowing the block | |
3842 | to go unreachable. */ | |
3843 | if (new_region == NULL) | |
3844 | { | |
3845 | gcc_assert (e_out == NULL); | |
3846 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ) | |
3847 | if (e->flags & EDGE_EH) | |
3848 | { | |
3849 | gimple stmt = last_stmt (e->src); | |
3850 | remove_stmt_from_eh_lp (stmt); | |
3851 | remove_edge (e); | |
3852 | } | |
3853 | else | |
3854 | ei_next (&ei); | |
3855 | goto succeed; | |
3856 | } | |
3857 | ||
3858 | /* If the destination region is a MUST_NOT_THROW, allow the runtime | |
3859 | to handle the abort and allow the blocks to go unreachable. */ | |
3860 | if (new_region->type == ERT_MUST_NOT_THROW) | |
3861 | { | |
3862 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ) | |
3863 | if (e->flags & EDGE_EH) | |
3864 | { | |
3865 | gimple stmt = last_stmt (e->src); | |
3866 | remove_stmt_from_eh_lp (stmt); | |
3867 | add_stmt_to_eh_lp (stmt, new_lp_nr); | |
3868 | remove_edge (e); | |
3869 | } | |
3870 | else | |
3871 | ei_next (&ei); | |
3872 | goto succeed; | |
3873 | } | |
3874 | ||
3875 | /* Try to redirect the EH edges and merge the PHIs into the destination | |
3876 | landing pad block. If the merge succeeds, we'll already have redirected | |
3877 | all the EH edges. The handler itself will go unreachable if there were | |
3878 | no normal edges. */ | |
c57e3b9d | 3879 | if (cleanup_empty_eh_merge_phis (e_out->dest, bb, e_out, true)) |
e38def9c | 3880 | goto succeed; |
3881 | ||
3882 | /* Finally, if all input edges are EH edges, then we can (potentially) | |
3883 | reduce the number of transfers from the runtime by moving the landing | |
3884 | pad from the original region to the new region. This is a win when | |
3885 | we remove the last CLEANUP region along a particular exception | |
3886 | propagation path. Since nothing changes except for the region with | |
3887 | which the landing pad is associated, the PHI nodes do not need to be | |
3888 | adjusted at all. */ | |
3889 | if (!has_non_eh_pred) | |
3890 | { | |
3891 | cleanup_empty_eh_move_lp (bb, e_out, lp, new_region); | |
3892 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3893 | fprintf (dump_file, "Empty EH handler %i moved to EH region %i.\n", | |
3894 | lp->index, new_region->index); | |
3895 | ||
3896 | /* ??? The CFG didn't change, but we may have rendered the | |
3897 | old EH region unreachable. Trigger a cleanup there. */ | |
4c5fcca6 | 3898 | return true; |
3899 | } | |
e38def9c | 3900 | |
4c5fcca6 | 3901 | return false; |
e38def9c | 3902 | |
3903 | succeed: | |
3904 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3905 | fprintf (dump_file, "Empty EH handler %i removed.\n", lp->index); | |
3906 | remove_eh_landing_pad (lp); | |
3907 | return true; | |
4c5fcca6 | 3908 | } |
3909 | ||
e38def9c | 3910 | /* Do a post-order traversal of the EH region tree. Examine each |
3911 | post_landing_pad block and see if we can eliminate it as empty. */ | |
3912 | ||
3913 | static bool | |
3914 | cleanup_all_empty_eh (void) | |
3915 | { | |
3916 | bool changed = false; | |
3917 | eh_landing_pad lp; | |
3918 | int i; | |
3919 | ||
3920 | for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i) | |
3921 | if (lp) | |
3922 | changed |= cleanup_empty_eh (lp); | |
3923 | ||
3924 | return changed; | |
3925 | } | |
4c5fcca6 | 3926 | |
3927 | /* Perform cleanups and lowering of exception handling | |
3928 | 1) cleanups regions with handlers doing nothing are optimized out | |
3929 | 2) MUST_NOT_THROW regions that became dead because of 1) are optimized out | |
3930 | 3) Info about regions that are containing instructions, and regions | |
3931 | reachable via local EH edges is collected | |
3932 | 4) Eh tree is pruned for regions no longer neccesary. | |
e38def9c | 3933 | |
3934 | TODO: Push MUST_NOT_THROW regions to the root of the EH tree. | |
3935 | Unify those that have the same failure decl and locus. | |
3936 | */ | |
4c5fcca6 | 3937 | |
3938 | static unsigned int | |
15100018 | 3939 | execute_cleanup_eh_1 (void) |
4c5fcca6 | 3940 | { |
e38def9c | 3941 | /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die |
3942 | looking up unreachable landing pads. */ | |
3943 | remove_unreachable_handlers (); | |
4c5fcca6 | 3944 | |
e38def9c | 3945 | /* Watch out for the region tree vanishing due to all unreachable. */ |
3946 | if (cfun->eh->region_tree && optimize) | |
4c5fcca6 | 3947 | { |
e38def9c | 3948 | bool changed = false; |
4c5fcca6 | 3949 | |
e38def9c | 3950 | changed |= unsplit_all_eh (); |
3951 | changed |= cleanup_all_empty_eh (); | |
3952 | ||
3953 | if (changed) | |
48d5ef93 | 3954 | { |
3955 | free_dominance_info (CDI_DOMINATORS); | |
3956 | free_dominance_info (CDI_POST_DOMINATORS); | |
4c5fcca6 | 3957 | |
e38def9c | 3958 | /* We delayed all basic block deletion, as we may have performed |
3959 | cleanups on EH edges while non-EH edges were still present. */ | |
3960 | delete_unreachable_blocks (); | |
4c5fcca6 | 3961 | |
e38def9c | 3962 | /* We manipulated the landing pads. Remove any region that no |
3963 | longer has a landing pad. */ | |
3964 | remove_unreachable_handlers_no_lp (); | |
3965 | ||
3966 | return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals; | |
3967 | } | |
4c5fcca6 | 3968 | } |
3969 | ||
e38def9c | 3970 | return 0; |
3971 | } | |
3972 | ||
15100018 | 3973 | static unsigned int |
3974 | execute_cleanup_eh (void) | |
3975 | { | |
3976 | int ret = execute_cleanup_eh_1 (); | |
3977 | ||
3978 | /* If the function no longer needs an EH personality routine | |
3979 | clear it. This exposes cross-language inlining opportunities | |
3980 | and avoids references to a never defined personality routine. */ | |
3981 | if (DECL_FUNCTION_PERSONALITY (current_function_decl) | |
3982 | && function_needs_eh_personality (cfun) != eh_personality_lang) | |
3983 | DECL_FUNCTION_PERSONALITY (current_function_decl) = NULL_TREE; | |
3984 | ||
3985 | return ret; | |
3986 | } | |
3987 | ||
e38def9c | 3988 | static bool |
3989 | gate_cleanup_eh (void) | |
3990 | { | |
3991 | return cfun->eh != NULL && cfun->eh->region_tree != NULL; | |
4c5fcca6 | 3992 | } |
3993 | ||
3994 | struct gimple_opt_pass pass_cleanup_eh = { | |
3995 | { | |
3996 | GIMPLE_PASS, | |
3997 | "ehcleanup", /* name */ | |
e38def9c | 3998 | gate_cleanup_eh, /* gate */ |
3999 | execute_cleanup_eh, /* execute */ | |
4c5fcca6 | 4000 | NULL, /* sub */ |
4001 | NULL, /* next */ | |
4002 | 0, /* static_pass_number */ | |
4003 | TV_TREE_EH, /* tv_id */ | |
4004 | PROP_gimple_lcf, /* properties_required */ | |
4005 | 0, /* properties_provided */ | |
4006 | 0, /* properties_destroyed */ | |
4007 | 0, /* todo_flags_start */ | |
4008 | TODO_dump_func /* todo_flags_finish */ | |
4009 | } | |
4010 | }; | |
e38def9c | 4011 | \f |
4012 | /* Verify that BB containing STMT as the last statement, has precisely the | |
4013 | edge that make_eh_edges would create. */ | |
4014 | ||
4b987fac | 4015 | DEBUG_FUNCTION bool |
e38def9c | 4016 | verify_eh_edges (gimple stmt) |
4017 | { | |
4018 | basic_block bb = gimple_bb (stmt); | |
4019 | eh_landing_pad lp = NULL; | |
4020 | int lp_nr; | |
4021 | edge_iterator ei; | |
4022 | edge e, eh_edge; | |
4023 | ||
4024 | lp_nr = lookup_stmt_eh_lp (stmt); | |
4025 | if (lp_nr > 0) | |
4026 | lp = get_eh_landing_pad_from_number (lp_nr); | |
4027 | ||
4028 | eh_edge = NULL; | |
4029 | FOR_EACH_EDGE (e, ei, bb->succs) | |
4030 | { | |
4031 | if (e->flags & EDGE_EH) | |
4032 | { | |
4033 | if (eh_edge) | |
4034 | { | |
4035 | error ("BB %i has multiple EH edges", bb->index); | |
4036 | return true; | |
4037 | } | |
4038 | else | |
4039 | eh_edge = e; | |
4040 | } | |
4041 | } | |
4042 | ||
4043 | if (lp == NULL) | |
4044 | { | |
4045 | if (eh_edge) | |
4046 | { | |
4047 | error ("BB %i can not throw but has an EH edge", bb->index); | |
4048 | return true; | |
4049 | } | |
4050 | return false; | |
4051 | } | |
4052 | ||
4053 | if (!stmt_could_throw_p (stmt)) | |
4054 | { | |
4055 | error ("BB %i last statement has incorrectly set lp", bb->index); | |
4056 | return true; | |
4057 | } | |
4058 | ||
4059 | if (eh_edge == NULL) | |
4060 | { | |
4061 | error ("BB %i is missing an EH edge", bb->index); | |
4062 | return true; | |
4063 | } | |
4064 | ||
4065 | if (eh_edge->dest != label_to_block (lp->post_landing_pad)) | |
4066 | { | |
4067 | error ("Incorrect EH edge %i->%i", bb->index, eh_edge->dest->index); | |
4068 | return true; | |
4069 | } | |
4070 | ||
4071 | return false; | |
4072 | } | |
4073 | ||
4074 | /* Similarly, but handle GIMPLE_EH_DISPATCH specifically. */ | |
4075 | ||
4b987fac | 4076 | DEBUG_FUNCTION bool |
e38def9c | 4077 | verify_eh_dispatch_edge (gimple stmt) |
4078 | { | |
4079 | eh_region r; | |
4080 | eh_catch c; | |
4081 | basic_block src, dst; | |
4082 | bool want_fallthru = true; | |
4083 | edge_iterator ei; | |
4084 | edge e, fall_edge; | |
4085 | ||
4086 | r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt)); | |
4087 | src = gimple_bb (stmt); | |
4088 | ||
4089 | FOR_EACH_EDGE (e, ei, src->succs) | |
4090 | gcc_assert (e->aux == NULL); | |
4091 | ||
4092 | switch (r->type) | |
4093 | { | |
4094 | case ERT_TRY: | |
4095 | for (c = r->u.eh_try.first_catch; c ; c = c->next_catch) | |
4096 | { | |
4097 | dst = label_to_block (c->label); | |
4098 | e = find_edge (src, dst); | |
4099 | if (e == NULL) | |
4100 | { | |
4101 | error ("BB %i is missing an edge", src->index); | |
4102 | return true; | |
4103 | } | |
4104 | e->aux = (void *)e; | |
4105 | ||
4106 | /* A catch-all handler doesn't have a fallthru. */ | |
4107 | if (c->type_list == NULL) | |
4108 | { | |
4109 | want_fallthru = false; | |
4110 | break; | |
4111 | } | |
4112 | } | |
4113 | break; | |
4114 | ||
4115 | case ERT_ALLOWED_EXCEPTIONS: | |
4116 | dst = label_to_block (r->u.allowed.label); | |
4117 | e = find_edge (src, dst); | |
4118 | if (e == NULL) | |
4119 | { | |
4120 | error ("BB %i is missing an edge", src->index); | |
4121 | return true; | |
4122 | } | |
4123 | e->aux = (void *)e; | |
4124 | break; | |
4125 | ||
4126 | default: | |
4127 | gcc_unreachable (); | |
4128 | } | |
4129 | ||
4130 | fall_edge = NULL; | |
4131 | FOR_EACH_EDGE (e, ei, src->succs) | |
4132 | { | |
4133 | if (e->flags & EDGE_FALLTHRU) | |
4134 | { | |
4135 | if (fall_edge != NULL) | |
4136 | { | |
4137 | error ("BB %i too many fallthru edges", src->index); | |
4138 | return true; | |
4139 | } | |
4140 | fall_edge = e; | |
4141 | } | |
4142 | else if (e->aux) | |
4143 | e->aux = NULL; | |
4144 | else | |
4145 | { | |
4146 | error ("BB %i has incorrect edge", src->index); | |
4147 | return true; | |
4148 | } | |
4149 | } | |
4150 | if ((fall_edge != NULL) ^ want_fallthru) | |
4151 | { | |
4152 | error ("BB %i has incorrect fallthru edge", src->index); | |
4153 | return true; | |
4154 | } | |
4155 | ||
4156 | return false; | |
4157 | } |