1/* Implements exception handling. 2 Copyright (C) 1989-2015 Free Software Foundation, Inc. 3 Contributed by Mike Stump <mrs@cygnus.com>. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 3, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING3. If not see 19<http://www.gnu.org/licenses/>. */ 20 21 22/* An exception is an event that can be "thrown" from within a 23 function. This event can then be "caught" by the callers of 24 the function. 25 26 The representation of exceptions changes several times during 27 the compilation process: 28 29 In the beginning, in the front end, we have the GENERIC trees 30 TRY_CATCH_EXPR, TRY_FINALLY_EXPR, WITH_CLEANUP_EXPR, 31 CLEANUP_POINT_EXPR, CATCH_EXPR, and EH_FILTER_EXPR. 32 33 During initial gimplification (gimplify.c) these are lowered 34 to the GIMPLE_TRY, GIMPLE_CATCH, and GIMPLE_EH_FILTER nodes. 35 The WITH_CLEANUP_EXPR and CLEANUP_POINT_EXPR nodes are converted 36 into GIMPLE_TRY_FINALLY nodes; the others are a more direct 1-1 37 conversion. 38 39 During pass_lower_eh (tree-eh.c) we record the nested structure 40 of the TRY nodes in EH_REGION nodes in CFUN->EH->REGION_TREE. 41 We expand the eh_protect_cleanup_actions langhook into MUST_NOT_THROW 42 regions at this time. We can then flatten the statements within 43 the TRY nodes to straight-line code. Statements that had been within 44 TRY nodes that can throw are recorded within CFUN->EH->THROW_STMT_TABLE, 45 so that we may remember what action is supposed to be taken if 46 a given statement does throw. During this lowering process, 47 we create an EH_LANDING_PAD node for each EH_REGION that has 48 some code within the function that needs to be executed if a 49 throw does happen. We also create RESX statements that are 50 used to transfer control from an inner EH_REGION to an outer 51 EH_REGION. We also create EH_DISPATCH statements as placeholders 52 for a runtime type comparison that should be made in order to 53 select the action to perform among different CATCH and EH_FILTER 54 regions. 55 56 During pass_lower_eh_dispatch (tree-eh.c), which is run after 57 all inlining is complete, we are able to run assign_filter_values, 58 which allows us to map the set of types manipulated by all of the 59 CATCH and EH_FILTER regions to a set of integers. This set of integers 60 will be how the exception runtime communicates with the code generated 61 within the function. We then expand the GIMPLE_EH_DISPATCH statements 62 to a switch or conditional branches that use the argument provided by 63 the runtime (__builtin_eh_filter) and the set of integers we computed 64 in assign_filter_values. 65 66 During pass_lower_resx (tree-eh.c), which is run near the end 67 of optimization, we expand RESX statements. If the eh region 68 that is outer to the RESX statement is a MUST_NOT_THROW, then 69 the RESX expands to some form of abort statement. If the eh 70 region that is outer to the RESX statement is within the current 71 function, then the RESX expands to a bookkeeping call 72 (__builtin_eh_copy_values) and a goto. Otherwise, the next 73 handler for the exception must be within a function somewhere 74 up the call chain, so we call back into the exception runtime 75 (__builtin_unwind_resume). 76 77 During pass_expand (cfgexpand.c), we generate REG_EH_REGION notes 78 that create an rtl to eh_region mapping that corresponds to the 79 gimple to eh_region mapping that had been recorded in the 80 THROW_STMT_TABLE. 81 82 Then, via finish_eh_generation, we generate the real landing pads 83 to which the runtime will actually transfer control. These new 84 landing pads perform whatever bookkeeping is needed by the target 85 backend in order to resume execution within the current function. 86 Each of these new landing pads falls through into the post_landing_pad 87 label which had been used within the CFG up to this point. All 88 exception edges within the CFG are redirected to the new landing pads. 89 If the target uses setjmp to implement exceptions, the various extra 90 calls into the runtime to register and unregister the current stack 91 frame are emitted at this time. 92 93 During pass_convert_to_eh_region_ranges (except.c), we transform 94 the REG_EH_REGION notes attached to individual insns into 95 non-overlapping ranges of insns bounded by NOTE_INSN_EH_REGION_BEG 96 and NOTE_INSN_EH_REGION_END. Each insn within such ranges has the 97 same associated action within the exception region tree, meaning 98 that (1) the exception is caught by the same landing pad within the 99 current function, (2) the exception is blocked by the runtime with 100 a MUST_NOT_THROW region, or (3) the exception is not handled at all 101 within the current function. 102 103 Finally, during assembly generation, we call 104 output_function_exception_table (except.c) to emit the tables with 105 which the exception runtime can determine if a given stack frame 106 handles a given exception, and if so what filter value to provide 107 to the function when the non-local control transfer is effected. 108 If the target uses dwarf2 unwinding to implement exceptions, then 109 output_call_frame_info (dwarf2out.c) emits the required unwind data. */ 110 111 112#include "config.h" 113#include "system.h" 114#include "coretypes.h" 115#include "tm.h" 116#include "rtl.h" 117#include "hash-set.h" 118#include "machmode.h" 119#include "vec.h" 120#include "double-int.h" 121#include "input.h" 122#include "alias.h" 123#include "symtab.h" 124#include "wide-int.h" 125#include "inchash.h" 126#include "real.h" 127#include "tree.h" 128#include "fold-const.h" 129#include "stringpool.h" 130#include "stor-layout.h" 131#include "flags.h" 132#include "hard-reg-set.h" 133#include "function.h" 134#include "insn-codes.h" 135#include "optabs.h" 136#include "hashtab.h" 137#include "statistics.h" 138#include "fixed-value.h" 139#include "insn-config.h" 140#include "expmed.h" 141#include "dojump.h" 142#include "explow.h" 143#include "calls.h" 144#include "emit-rtl.h" 145#include "varasm.h" 146#include "stmt.h" 147#include "expr.h" 148#include "libfuncs.h" 149#include "except.h" 150#include "output.h" 151#include "dwarf2asm.h" 152#include "dwarf2out.h" 153#include "dwarf2.h" 154#include "toplev.h" 155#include "hash-table.h" 156#include "intl.h" 157#include "tm_p.h" 158#include "target.h" 159#include "common/common-target.h" 160#include "langhooks.h" 161#include "predict.h" 162#include "dominance.h" 163#include "cfg.h" 164#include "cfgrtl.h" 165#include "basic-block.h" 166#include "hash-map.h" 167#include "is-a.h" 168#include "plugin-api.h" 169#include "ipa-ref.h" 170#include "cgraph.h" 171#include "diagnostic.h" 172#include "tree-pretty-print.h" 173#include "tree-pass.h" 174#include "cfgloop.h" 175#include "builtins.h" 176 177/* Provide defaults for stuff that may not be defined when using 178 sjlj exceptions. */ 179#ifndef EH_RETURN_DATA_REGNO 180#define EH_RETURN_DATA_REGNO(N) INVALID_REGNUM 181#endif 182 183static GTY(()) int call_site_base; 184 185struct tree_hash_traits : default_hashmap_traits 186{ 187 static hashval_t hash (tree t) { return TREE_HASH (t); } 188}; 189 190static GTY (()) hash_map<tree, tree, tree_hash_traits> *type_to_runtime_map; 191 192/* Describe the SjLj_Function_Context structure. */ 193static GTY(()) tree sjlj_fc_type_node; 194static int sjlj_fc_call_site_ofs; 195static int sjlj_fc_data_ofs; 196static int sjlj_fc_personality_ofs; 197static int sjlj_fc_lsda_ofs; 198static int sjlj_fc_jbuf_ofs; 199 200 201struct GTY(()) call_site_record_d 202{ 203 rtx landing_pad; 204 int action; 205}; 206 207/* In the following structure and associated functions, 208 we represent entries in the action table as 1-based indices. 209 Special cases are: 210 211 0: null action record, non-null landing pad; implies cleanups 212 -1: null action record, null landing pad; implies no action 213 -2: no call-site entry; implies must_not_throw 214 -3: we have yet to process outer regions 215 216 Further, no special cases apply to the "next" field of the record. 217 For next, 0 means end of list. */ 218 219struct action_record 220{ 221 int offset; 222 int filter; 223 int next; 224}; 225 226/* Hashtable helpers. */ 227 228struct action_record_hasher : typed_free_remove <action_record> 229{ 230 typedef action_record value_type; 231 typedef action_record compare_type; 232 static inline hashval_t hash (const value_type *); 233 static inline bool equal (const value_type *, const compare_type *); 234}; 235 236inline hashval_t 237action_record_hasher::hash (const value_type *entry) 238{ 239 return entry->next * 1009 + entry->filter; 240} 241 242inline bool 243action_record_hasher::equal (const value_type *entry, const compare_type *data) 244{ 245 return entry->filter == data->filter && entry->next == data->next; 246} 247 248typedef hash_table<action_record_hasher> action_hash_type; 249 250static bool get_eh_region_and_lp_from_rtx (const_rtx, eh_region *, 251 eh_landing_pad *); 252 253static void dw2_build_landing_pads (void); 254 255static int collect_one_action_chain (action_hash_type *, eh_region); 256static int add_call_site (rtx, int, int); 257 258static void push_uleb128 (vec<uchar, va_gc> **, unsigned int); 259static void push_sleb128 (vec<uchar, va_gc> **, int); 260#ifndef HAVE_AS_LEB128 261static int dw2_size_of_call_site_table (int); 262static int sjlj_size_of_call_site_table (void); 263#endif 264static void dw2_output_call_site_table (int, int); 265static void sjlj_output_call_site_table (void); 266 267 268void 269init_eh (void) 270{ 271 if (! flag_exceptions) 272 return; 273 274 type_to_runtime_map 275 = hash_map<tree, tree, tree_hash_traits>::create_ggc (31); 276 277 /* Create the SjLj_Function_Context structure. This should match 278 the definition in unwind-sjlj.c. */ 279 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) 280 { 281 tree f_jbuf, f_per, f_lsda, f_prev, f_cs, f_data, tmp; 282 283 sjlj_fc_type_node = lang_hooks.types.make_type (RECORD_TYPE); 284 285 f_prev = build_decl (BUILTINS_LOCATION, 286 FIELD_DECL, get_identifier ("__prev"), 287 build_pointer_type (sjlj_fc_type_node)); 288 DECL_FIELD_CONTEXT (f_prev) = sjlj_fc_type_node; 289 290 f_cs = build_decl (BUILTINS_LOCATION, 291 FIELD_DECL, get_identifier ("__call_site"), 292 integer_type_node); 293 DECL_FIELD_CONTEXT (f_cs) = sjlj_fc_type_node; 294 295 tmp = build_index_type (size_int (4 - 1)); 296 tmp = build_array_type (lang_hooks.types.type_for_mode 297 (targetm.unwind_word_mode (), 1), 298 tmp); 299 f_data = build_decl (BUILTINS_LOCATION, 300 FIELD_DECL, get_identifier ("__data"), tmp); 301 DECL_FIELD_CONTEXT (f_data) = sjlj_fc_type_node; 302 303 f_per = build_decl (BUILTINS_LOCATION, 304 FIELD_DECL, get_identifier ("__personality"), 305 ptr_type_node); 306 DECL_FIELD_CONTEXT (f_per) = sjlj_fc_type_node; 307 308 f_lsda = build_decl (BUILTINS_LOCATION, 309 FIELD_DECL, get_identifier ("__lsda"), 310 ptr_type_node); 311 DECL_FIELD_CONTEXT (f_lsda) = sjlj_fc_type_node; 312 313#ifdef DONT_USE_BUILTIN_SETJMP 314#ifdef JMP_BUF_SIZE 315 tmp = size_int (JMP_BUF_SIZE - 1); 316#else 317 /* Should be large enough for most systems, if it is not, 318 JMP_BUF_SIZE should be defined with the proper value. It will 319 also tend to be larger than necessary for most systems, a more 320 optimal port will define JMP_BUF_SIZE. */ 321 tmp = size_int (FIRST_PSEUDO_REGISTER + 2 - 1); 322#endif 323#else 324 /* Compute a minimally sized jump buffer. We need room to store at 325 least 3 pointers - stack pointer, frame pointer and return address. 326 Plus for some targets we need room for an extra pointer - in the 327 case of MIPS this is the global pointer. This makes a total of four 328 pointers, but to be safe we actually allocate room for 5. 329 330 If pointers are smaller than words then we allocate enough room for 331 5 words, just in case the backend needs this much room. For more 332 discussion on this issue see: 333 http://gcc.gnu.org/ml/gcc-patches/2014-05/msg00313.html. */ 334 if (POINTER_SIZE > BITS_PER_WORD) 335 tmp = size_int (5 - 1); 336 else 337 tmp = size_int ((5 * BITS_PER_WORD / POINTER_SIZE) - 1); 338#endif 339 340 tmp = build_index_type (tmp); 341 tmp = build_array_type (ptr_type_node, tmp); 342 f_jbuf = build_decl (BUILTINS_LOCATION, 343 FIELD_DECL, get_identifier ("__jbuf"), tmp); 344#ifdef DONT_USE_BUILTIN_SETJMP 345 /* We don't know what the alignment requirements of the 346 runtime's jmp_buf has. Overestimate. */ 347 DECL_ALIGN (f_jbuf) = BIGGEST_ALIGNMENT; 348 DECL_USER_ALIGN (f_jbuf) = 1; 349#endif 350 DECL_FIELD_CONTEXT (f_jbuf) = sjlj_fc_type_node; 351 352 TYPE_FIELDS (sjlj_fc_type_node) = f_prev; 353 TREE_CHAIN (f_prev) = f_cs; 354 TREE_CHAIN (f_cs) = f_data; 355 TREE_CHAIN (f_data) = f_per; 356 TREE_CHAIN (f_per) = f_lsda; 357 TREE_CHAIN (f_lsda) = f_jbuf; 358 359 layout_type (sjlj_fc_type_node); 360 361 /* Cache the interesting field offsets so that we have 362 easy access from rtl. */ 363 sjlj_fc_call_site_ofs 364 = (tree_to_uhwi (DECL_FIELD_OFFSET (f_cs)) 365 + tree_to_uhwi (DECL_FIELD_BIT_OFFSET (f_cs)) / BITS_PER_UNIT); 366 sjlj_fc_data_ofs 367 = (tree_to_uhwi (DECL_FIELD_OFFSET (f_data)) 368 + tree_to_uhwi (DECL_FIELD_BIT_OFFSET (f_data)) / BITS_PER_UNIT); 369 sjlj_fc_personality_ofs 370 = (tree_to_uhwi (DECL_FIELD_OFFSET (f_per)) 371 + tree_to_uhwi (DECL_FIELD_BIT_OFFSET (f_per)) / BITS_PER_UNIT); 372 sjlj_fc_lsda_ofs 373 = (tree_to_uhwi (DECL_FIELD_OFFSET (f_lsda)) 374 + tree_to_uhwi (DECL_FIELD_BIT_OFFSET (f_lsda)) / BITS_PER_UNIT); 375 sjlj_fc_jbuf_ofs 376 = (tree_to_uhwi (DECL_FIELD_OFFSET (f_jbuf)) 377 + tree_to_uhwi (DECL_FIELD_BIT_OFFSET (f_jbuf)) / BITS_PER_UNIT); 378 } 379} 380 381void 382init_eh_for_function (void) 383{ 384 cfun->eh = ggc_cleared_alloc<eh_status> (); 385 386 /* Make sure zero'th entries are used. */ 387 vec_safe_push (cfun->eh->region_array, (eh_region)0); 388 vec_safe_push (cfun->eh->lp_array, (eh_landing_pad)0); 389} 390 391/* Routines to generate the exception tree somewhat directly. 392 These are used from tree-eh.c when processing exception related 393 nodes during tree optimization. */ 394 395static eh_region 396gen_eh_region (enum eh_region_type type, eh_region outer) 397{ 398 eh_region new_eh; 399 400 /* Insert a new blank region as a leaf in the tree. */ 401 new_eh = ggc_cleared_alloc<eh_region_d> (); 402 new_eh->type = type; 403 new_eh->outer = outer; 404 if (outer) 405 { 406 new_eh->next_peer = outer->inner; 407 outer->inner = new_eh; 408 } 409 else 410 { 411 new_eh->next_peer = cfun->eh->region_tree; 412 cfun->eh->region_tree = new_eh; 413 } 414 415 new_eh->index = vec_safe_length (cfun->eh->region_array); 416 vec_safe_push (cfun->eh->region_array, new_eh); 417 418 /* Copy the language's notion of whether to use __cxa_end_cleanup. */ 419 if (targetm.arm_eabi_unwinder && lang_hooks.eh_use_cxa_end_cleanup) 420 new_eh->use_cxa_end_cleanup = true; 421 422 return new_eh; 423} 424 425eh_region 426gen_eh_region_cleanup (eh_region outer) 427{ 428 return gen_eh_region (ERT_CLEANUP, outer); 429} 430 431eh_region 432gen_eh_region_try (eh_region outer) 433{ 434 return gen_eh_region (ERT_TRY, outer); 435} 436 437eh_catch 438gen_eh_region_catch (eh_region t, tree type_or_list) 439{ 440 eh_catch c, l; 441 tree type_list, type_node; 442 443 gcc_assert (t->type == ERT_TRY); 444 445 /* Ensure to always end up with a type list to normalize further 446 processing, then register each type against the runtime types map. */ 447 type_list = type_or_list; 448 if (type_or_list) 449 { 450 if (TREE_CODE (type_or_list) != TREE_LIST) 451 type_list = tree_cons (NULL_TREE, type_or_list, NULL_TREE); 452 453 type_node = type_list; 454 for (; type_node; type_node = TREE_CHAIN (type_node)) 455 add_type_for_runtime (TREE_VALUE (type_node)); 456 } 457 458 c = ggc_cleared_alloc<eh_catch_d> (); 459 c->type_list = type_list; 460 l = t->u.eh_try.last_catch; 461 c->prev_catch = l; 462 if (l) 463 l->next_catch = c; 464 else 465 t->u.eh_try.first_catch = c; 466 t->u.eh_try.last_catch = c; 467 468 return c; 469} 470 471eh_region 472gen_eh_region_allowed (eh_region outer, tree allowed) 473{ 474 eh_region region = gen_eh_region (ERT_ALLOWED_EXCEPTIONS, outer); 475 region->u.allowed.type_list = allowed; 476 477 for (; allowed ; allowed = TREE_CHAIN (allowed)) 478 add_type_for_runtime (TREE_VALUE (allowed)); 479 480 return region; 481} 482 483eh_region 484gen_eh_region_must_not_throw (eh_region outer) 485{ 486 return gen_eh_region (ERT_MUST_NOT_THROW, outer); 487} 488 489eh_landing_pad 490gen_eh_landing_pad (eh_region region) 491{ 492 eh_landing_pad lp = ggc_cleared_alloc<eh_landing_pad_d> (); 493 494 lp->next_lp = region->landing_pads; 495 lp->region = region; 496 lp->index = vec_safe_length (cfun->eh->lp_array); 497 region->landing_pads = lp; 498 499 vec_safe_push (cfun->eh->lp_array, lp); 500 501 return lp; 502} 503 504eh_region 505get_eh_region_from_number_fn (struct function *ifun, int i) 506{ 507 return (*ifun->eh->region_array)[i]; 508} 509 510eh_region 511get_eh_region_from_number (int i) 512{ 513 return get_eh_region_from_number_fn (cfun, i); 514} 515 516eh_landing_pad 517get_eh_landing_pad_from_number_fn (struct function *ifun, int i) 518{ 519 return (*ifun->eh->lp_array)[i]; 520} 521 522eh_landing_pad 523get_eh_landing_pad_from_number (int i) 524{ 525 return get_eh_landing_pad_from_number_fn (cfun, i); 526} 527 528eh_region 529get_eh_region_from_lp_number_fn (struct function *ifun, int i) 530{ 531 if (i < 0) 532 return (*ifun->eh->region_array)[-i]; 533 else if (i == 0) 534 return NULL; 535 else 536 { 537 eh_landing_pad lp; 538 lp = (*ifun->eh->lp_array)[i]; 539 return lp->region; 540 } 541} 542 543eh_region 544get_eh_region_from_lp_number (int i) 545{ 546 return get_eh_region_from_lp_number_fn (cfun, i); 547} 548 549/* Returns true if the current function has exception handling regions. */ 550 551bool 552current_function_has_exception_handlers (void) 553{ 554 return cfun->eh->region_tree != NULL; 555} 556 557/* A subroutine of duplicate_eh_regions. Copy the eh_region tree at OLD. 558 Root it at OUTER, and apply LP_OFFSET to the lp numbers. */ 559 560struct duplicate_eh_regions_data 561{ 562 duplicate_eh_regions_map label_map; 563 void *label_map_data; 564 hash_map<void *, void *> *eh_map; 565}; 566 567static void 568duplicate_eh_regions_1 (struct duplicate_eh_regions_data *data, 569 eh_region old_r, eh_region outer) 570{ 571 eh_landing_pad old_lp, new_lp; 572 eh_region new_r; 573 574 new_r = gen_eh_region (old_r->type, outer); 575 gcc_assert (!data->eh_map->put (old_r, new_r)); 576 577 switch (old_r->type) 578 { 579 case ERT_CLEANUP: 580 break; 581 582 case ERT_TRY: 583 { 584 eh_catch oc, nc; 585 for (oc = old_r->u.eh_try.first_catch; oc ; oc = oc->next_catch) 586 { 587 /* We should be doing all our region duplication before and 588 during inlining, which is before filter lists are created. */ 589 gcc_assert (oc->filter_list == NULL); 590 nc = gen_eh_region_catch (new_r, oc->type_list); 591 nc->label = data->label_map (oc->label, data->label_map_data); 592 } 593 } 594 break; 595 596 case ERT_ALLOWED_EXCEPTIONS: 597 new_r->u.allowed.type_list = old_r->u.allowed.type_list; 598 if (old_r->u.allowed.label) 599 new_r->u.allowed.label 600 = data->label_map (old_r->u.allowed.label, data->label_map_data); 601 else 602 new_r->u.allowed.label = NULL_TREE; 603 break; 604 605 case ERT_MUST_NOT_THROW: 606 new_r->u.must_not_throw.failure_loc = 607 LOCATION_LOCUS (old_r->u.must_not_throw.failure_loc); 608 new_r->u.must_not_throw.failure_decl = 609 old_r->u.must_not_throw.failure_decl; 610 break; 611 } 612 613 for (old_lp = old_r->landing_pads; old_lp ; old_lp = old_lp->next_lp) 614 { 615 /* Don't bother copying unused landing pads. */ 616 if (old_lp->post_landing_pad == NULL) 617 continue; 618 619 new_lp = gen_eh_landing_pad (new_r); 620 gcc_assert (!data->eh_map->put (old_lp, new_lp)); 621 622 new_lp->post_landing_pad 623 = data->label_map (old_lp->post_landing_pad, data->label_map_data); 624 EH_LANDING_PAD_NR (new_lp->post_landing_pad) = new_lp->index; 625 } 626 627 /* Make sure to preserve the original use of __cxa_end_cleanup. */ 628 new_r->use_cxa_end_cleanup = old_r->use_cxa_end_cleanup; 629 630 for (old_r = old_r->inner; old_r ; old_r = old_r->next_peer) 631 duplicate_eh_regions_1 (data, old_r, new_r); 632} 633 634/* Duplicate the EH regions from IFUN rooted at COPY_REGION into 635 the current function and root the tree below OUTER_REGION. 636 The special case of COPY_REGION of NULL means all regions. 637 Remap labels using MAP/MAP_DATA callback. Return a pointer map 638 that allows the caller to remap uses of both EH regions and 639 EH landing pads. */ 640 641hash_map<void *, void *> * 642duplicate_eh_regions (struct function *ifun, 643 eh_region copy_region, int outer_lp, 644 duplicate_eh_regions_map map, void *map_data) 645{ 646 struct duplicate_eh_regions_data data; 647 eh_region outer_region; 648 649#ifdef ENABLE_CHECKING 650 verify_eh_tree (ifun); 651#endif 652 653 data.label_map = map; 654 data.label_map_data = map_data; 655 data.eh_map = new hash_map<void *, void *>; 656 657 outer_region = get_eh_region_from_lp_number (outer_lp); 658 659 /* Copy all the regions in the subtree. */ 660 if (copy_region) 661 duplicate_eh_regions_1 (&data, copy_region, outer_region); 662 else 663 { 664 eh_region r; 665 for (r = ifun->eh->region_tree; r ; r = r->next_peer) 666 duplicate_eh_regions_1 (&data, r, outer_region); 667 } 668 669#ifdef ENABLE_CHECKING 670 verify_eh_tree (cfun); 671#endif 672 673 return data.eh_map; 674} 675 676/* Return the region that is outer to both REGION_A and REGION_B in IFUN. */ 677 678eh_region 679eh_region_outermost (struct function *ifun, eh_region region_a, 680 eh_region region_b) 681{ 682 sbitmap b_outer; 683 684 gcc_assert (ifun->eh->region_array); 685 gcc_assert (ifun->eh->region_tree); 686 687 b_outer = sbitmap_alloc (ifun->eh->region_array->length ()); 688 bitmap_clear (b_outer); 689 690 do 691 { 692 bitmap_set_bit (b_outer, region_b->index); 693 region_b = region_b->outer; 694 } 695 while (region_b); 696 697 do 698 { 699 if (bitmap_bit_p (b_outer, region_a->index)) 700 break; 701 region_a = region_a->outer; 702 } 703 while (region_a); 704 705 sbitmap_free (b_outer); 706 return region_a; 707} 708 709void 710add_type_for_runtime (tree type) 711{ 712 /* If TYPE is NOP_EXPR, it means that it already is a runtime type. */ 713 if (TREE_CODE (type) == NOP_EXPR) 714 return; 715 716 bool existed = false; 717 tree *slot = &type_to_runtime_map->get_or_insert (type, &existed); 718 if (!existed) 719 *slot = lang_hooks.eh_runtime_type (type); 720} 721 722tree 723lookup_type_for_runtime (tree type) 724{ 725 /* If TYPE is NOP_EXPR, it means that it already is a runtime type. */ 726 if (TREE_CODE (type) == NOP_EXPR) 727 return type; 728 729 /* We should have always inserted the data earlier. */ 730 return *type_to_runtime_map->get (type); 731} 732 733 734/* Represent an entry in @TTypes for either catch actions 735 or exception filter actions. */ 736struct ttypes_filter { 737 tree t; 738 int filter; 739}; 740 741/* Helper for ttypes_filter hashing. */ 742 743struct ttypes_filter_hasher : typed_free_remove <ttypes_filter> 744{ 745 typedef ttypes_filter value_type; 746 typedef tree_node compare_type; 747 static inline hashval_t hash (const value_type *); 748 static inline bool equal (const value_type *, const compare_type *); 749}; 750 751/* Compare ENTRY (a ttypes_filter entry in the hash table) with DATA 752 (a tree) for a @TTypes type node we are thinking about adding. */ 753 754inline bool 755ttypes_filter_hasher::equal (const value_type *entry, const compare_type *data) 756{ 757 return entry->t == data; 758} 759 760inline hashval_t 761ttypes_filter_hasher::hash (const value_type *entry) 762{ 763 return TREE_HASH (entry->t); 764} 765 766typedef hash_table<ttypes_filter_hasher> ttypes_hash_type; 767 768 769/* Helper for ehspec hashing. */ 770 771struct ehspec_hasher : typed_free_remove <ttypes_filter> 772{ 773 typedef ttypes_filter value_type; 774 typedef ttypes_filter compare_type; 775 static inline hashval_t hash (const value_type *); 776 static inline bool equal (const value_type *, const compare_type *); 777}; 778 779/* Compare ENTRY with DATA (both struct ttypes_filter) for a @TTypes 780 exception specification list we are thinking about adding. */ 781/* ??? Currently we use the type lists in the order given. Someone 782 should put these in some canonical order. */ 783 784inline bool 785ehspec_hasher::equal (const value_type *entry, const compare_type *data) 786{ 787 return type_list_equal (entry->t, data->t); 788} 789 790/* Hash function for exception specification lists. */ 791 792inline hashval_t 793ehspec_hasher::hash (const value_type *entry) 794{ 795 hashval_t h = 0; 796 tree list; 797 798 for (list = entry->t; list ; list = TREE_CHAIN (list)) 799 h = (h << 5) + (h >> 27) + TREE_HASH (TREE_VALUE (list)); 800 return h; 801} 802 803typedef hash_table<ehspec_hasher> ehspec_hash_type; 804 805 806/* Add TYPE (which may be NULL) to cfun->eh->ttype_data, using TYPES_HASH 807 to speed up the search. Return the filter value to be used. */ 808 809static int 810add_ttypes_entry (ttypes_hash_type *ttypes_hash, tree type) 811{ 812 struct ttypes_filter **slot, *n; 813 814 slot = ttypes_hash->find_slot_with_hash (type, (hashval_t) TREE_HASH (type), 815 INSERT); 816 817 if ((n = *slot) == NULL) 818 { 819 /* Filter value is a 1 based table index. */ 820 821 n = XNEW (struct ttypes_filter); 822 n->t = type; 823 n->filter = vec_safe_length (cfun->eh->ttype_data) + 1; 824 *slot = n; 825 826 vec_safe_push (cfun->eh->ttype_data, type); 827 } 828 829 return n->filter; 830} 831 832/* Add LIST to cfun->eh->ehspec_data, using EHSPEC_HASH and TYPES_HASH 833 to speed up the search. Return the filter value to be used. */ 834 835static int 836add_ehspec_entry (ehspec_hash_type *ehspec_hash, ttypes_hash_type *ttypes_hash, 837 tree list) 838{ 839 struct ttypes_filter **slot, *n; 840 struct ttypes_filter dummy; 841 842 dummy.t = list; 843 slot = ehspec_hash->find_slot (&dummy, INSERT); 844 845 if ((n = *slot) == NULL) 846 { 847 int len; 848 849 if (targetm.arm_eabi_unwinder) 850 len = vec_safe_length (cfun->eh->ehspec_data.arm_eabi); 851 else 852 len = vec_safe_length (cfun->eh->ehspec_data.other); 853 854 /* Filter value is a -1 based byte index into a uleb128 buffer. */ 855 856 n = XNEW (struct ttypes_filter); 857 n->t = list; 858 n->filter = -(len + 1); 859 *slot = n; 860 861 /* Generate a 0 terminated list of filter values. */ 862 for (; list ; list = TREE_CHAIN (list)) 863 { 864 if (targetm.arm_eabi_unwinder) 865 vec_safe_push (cfun->eh->ehspec_data.arm_eabi, TREE_VALUE (list)); 866 else 867 { 868 /* Look up each type in the list and encode its filter 869 value as a uleb128. */ 870 push_uleb128 (&cfun->eh->ehspec_data.other, 871 add_ttypes_entry (ttypes_hash, TREE_VALUE (list))); 872 } 873 } 874 if (targetm.arm_eabi_unwinder) 875 vec_safe_push (cfun->eh->ehspec_data.arm_eabi, NULL_TREE); 876 else 877 vec_safe_push (cfun->eh->ehspec_data.other, (uchar)0); 878 } 879 880 return n->filter; 881} 882 883/* Generate the action filter values to be used for CATCH and 884 ALLOWED_EXCEPTIONS regions. When using dwarf2 exception regions, 885 we use lots of landing pads, and so every type or list can share 886 the same filter value, which saves table space. */ 887 888void 889assign_filter_values (void) 890{ 891 int i; 892 eh_region r; 893 eh_catch c; 894 895 vec_alloc (cfun->eh->ttype_data, 16); 896 if (targetm.arm_eabi_unwinder) 897 vec_alloc (cfun->eh->ehspec_data.arm_eabi, 64); 898 else 899 vec_alloc (cfun->eh->ehspec_data.other, 64); 900 901 ehspec_hash_type ehspec (31); 902 ttypes_hash_type ttypes (31); 903 904 for (i = 1; vec_safe_iterate (cfun->eh->region_array, i, &r); ++i) 905 { 906 if (r == NULL) 907 continue; 908 909 switch (r->type) 910 { 911 case ERT_TRY: 912 for (c = r->u.eh_try.first_catch; c ; c = c->next_catch) 913 { 914 /* Whatever type_list is (NULL or true list), we build a list 915 of filters for the region. */ 916 c->filter_list = NULL_TREE; 917 918 if (c->type_list != NULL) 919 { 920 /* Get a filter value for each of the types caught and store 921 them in the region's dedicated list. */ 922 tree tp_node = c->type_list; 923 924 for ( ; tp_node; tp_node = TREE_CHAIN (tp_node)) 925 { 926 int flt 927 = add_ttypes_entry (&ttypes, TREE_VALUE (tp_node)); 928 tree flt_node = build_int_cst (integer_type_node, flt); 929 930 c->filter_list 931 = tree_cons (NULL_TREE, flt_node, c->filter_list); 932 } 933 } 934 else 935 { 936 /* Get a filter value for the NULL list also since it 937 will need an action record anyway. */ 938 int flt = add_ttypes_entry (&ttypes, NULL); 939 tree flt_node = build_int_cst (integer_type_node, flt); 940 941 c->filter_list 942 = tree_cons (NULL_TREE, flt_node, NULL); 943 } 944 } 945 break; 946 947 case ERT_ALLOWED_EXCEPTIONS: 948 r->u.allowed.filter 949 = add_ehspec_entry (&ehspec, &ttypes, r->u.allowed.type_list); 950 break; 951 952 default: 953 break; 954 } 955 } 956} 957 958/* Emit SEQ into basic block just before INSN (that is assumed to be 959 first instruction of some existing BB and return the newly 960 produced block. */ 961static basic_block 962emit_to_new_bb_before (rtx_insn *seq, rtx insn) 963{ 964 rtx_insn *last; 965 basic_block bb; 966 edge e; 967 edge_iterator ei; 968 969 /* If there happens to be a fallthru edge (possibly created by cleanup_cfg 970 call), we don't want it to go into newly created landing pad or other EH 971 construct. */ 972 for (ei = ei_start (BLOCK_FOR_INSN (insn)->preds); (e = ei_safe_edge (ei)); ) 973 if (e->flags & EDGE_FALLTHRU) 974 force_nonfallthru (e); 975 else 976 ei_next (&ei); 977 last = emit_insn_before (seq, insn); 978 if (BARRIER_P (last)) 979 last = PREV_INSN (last); 980 bb = create_basic_block (seq, last, BLOCK_FOR_INSN (insn)->prev_bb); 981 update_bb_for_insn (bb); 982 bb->flags |= BB_SUPERBLOCK; 983 return bb; 984} 985 986/* A subroutine of dw2_build_landing_pads, also used for edge splitting 987 at the rtl level. Emit the code required by the target at a landing 988 pad for the given region. */ 989 990void 991expand_dw2_landing_pad_for_region (eh_region region) 992{ 993#ifdef HAVE_exception_receiver 994 if (HAVE_exception_receiver) 995 emit_insn (gen_exception_receiver ()); 996 else 997#endif 998#ifdef HAVE_nonlocal_goto_receiver 999 if (HAVE_nonlocal_goto_receiver) 1000 emit_insn (gen_nonlocal_goto_receiver ()); 1001 else 1002#endif 1003 { /* Nothing */ } 1004 1005 if (region->exc_ptr_reg) 1006 emit_move_insn (region->exc_ptr_reg, 1007 gen_rtx_REG (ptr_mode, EH_RETURN_DATA_REGNO (0))); 1008 if (region->filter_reg) 1009 emit_move_insn (region->filter_reg, 1010 gen_rtx_REG (targetm.eh_return_filter_mode (), 1011 EH_RETURN_DATA_REGNO (1))); 1012} 1013 1014/* Expand the extra code needed at landing pads for dwarf2 unwinding. */ 1015 1016static void 1017dw2_build_landing_pads (void) 1018{ 1019 int i; 1020 eh_landing_pad lp; 1021 int e_flags = EDGE_FALLTHRU; 1022 1023 /* If we're going to partition blocks, we need to be able to add 1024 new landing pads later, which means that we need to hold on to 1025 the post-landing-pad block. Prevent it from being merged away. 1026 We'll remove this bit after partitioning. */ 1027 if (flag_reorder_blocks_and_partition) 1028 e_flags |= EDGE_PRESERVE; 1029 1030 for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i) 1031 { 1032 basic_block bb; 1033 rtx_insn *seq; 1034 edge e; 1035 1036 if (lp == NULL || lp->post_landing_pad == NULL) 1037 continue; 1038 1039 start_sequence (); 1040 1041 lp->landing_pad = gen_label_rtx (); 1042 emit_label (lp->landing_pad); 1043 LABEL_PRESERVE_P (lp->landing_pad) = 1; 1044 1045 expand_dw2_landing_pad_for_region (lp->region); 1046 1047 seq = get_insns (); 1048 end_sequence (); 1049 1050 bb = emit_to_new_bb_before (seq, label_rtx (lp->post_landing_pad)); 1051 e = make_edge (bb, bb->next_bb, e_flags); 1052 e->count = bb->count; 1053 e->probability = REG_BR_PROB_BASE; 1054 if (current_loops) 1055 { 1056 struct loop *loop = bb->next_bb->loop_father; 1057 /* If we created a pre-header block, add the new block to the 1058 outer loop, otherwise to the loop itself. */ 1059 if (bb->next_bb == loop->header) 1060 add_bb_to_loop (bb, loop_outer (loop)); 1061 else 1062 add_bb_to_loop (bb, loop); 1063 } 1064 } 1065} 1066 1067 1068static vec<int> sjlj_lp_call_site_index; 1069 1070/* Process all active landing pads. Assign each one a compact dispatch 1071 index, and a call-site index. */ 1072 1073static int 1074sjlj_assign_call_site_values (void) 1075{ 1076 action_hash_type ar_hash (31); 1077 int i, disp_index; 1078 eh_landing_pad lp; 1079 1080 vec_alloc (crtl->eh.action_record_data, 64); 1081 1082 disp_index = 0; 1083 call_site_base = 1; 1084 for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i) 1085 if (lp && lp->post_landing_pad) 1086 { 1087 int action, call_site; 1088 1089 /* First: build the action table. */ 1090 action = collect_one_action_chain (&ar_hash, lp->region); 1091 1092 /* Next: assign call-site values. If dwarf2 terms, this would be 1093 the region number assigned by convert_to_eh_region_ranges, but 1094 handles no-action and must-not-throw differently. */ 1095 /* Map must-not-throw to otherwise unused call-site index 0. */ 1096 if (action == -2) 1097 call_site = 0; 1098 /* Map no-action to otherwise unused call-site index -1. */ 1099 else if (action == -1) 1100 call_site = -1; 1101 /* Otherwise, look it up in the table. */ 1102 else 1103 call_site = add_call_site (GEN_INT (disp_index), action, 0); 1104 sjlj_lp_call_site_index[i] = call_site; 1105 1106 disp_index++; 1107 } 1108 1109 return disp_index; 1110} 1111 1112/* Emit code to record the current call-site index before every 1113 insn that can throw. */ 1114 1115static void 1116sjlj_mark_call_sites (void) 1117{ 1118 int last_call_site = -2; 1119 rtx_insn *insn; 1120 rtx mem; 1121 1122 for (insn = get_insns (); insn ; insn = NEXT_INSN (insn)) 1123 { 1124 eh_landing_pad lp; 1125 eh_region r; 1126 bool nothrow; 1127 int this_call_site; 1128 rtx_insn *before, *p; 1129 1130 /* Reset value tracking at extended basic block boundaries. */ 1131 if (LABEL_P (insn)) 1132 last_call_site = -2; 1133 1134 if (! INSN_P (insn)) 1135 continue; 1136 1137 nothrow = get_eh_region_and_lp_from_rtx (insn, &r, &lp); 1138 if (nothrow) 1139 continue; 1140 if (lp) 1141 this_call_site = sjlj_lp_call_site_index[lp->index]; 1142 else if (r == NULL) 1143 { 1144 /* Calls (and trapping insns) without notes are outside any 1145 exception handling region in this function. Mark them as 1146 no action. */ 1147 this_call_site = -1; 1148 } 1149 else 1150 { 1151 gcc_assert (r->type == ERT_MUST_NOT_THROW); 1152 this_call_site = 0; 1153 } 1154 1155 if (this_call_site != -1) 1156 crtl->uses_eh_lsda = 1; 1157 1158 if (this_call_site == last_call_site) 1159 continue; 1160 1161 /* Don't separate a call from it's argument loads. */ 1162 before = insn; 1163 if (CALL_P (insn)) 1164 before = find_first_parameter_load (insn, NULL); 1165 1166 start_sequence (); 1167 mem = adjust_address (crtl->eh.sjlj_fc, TYPE_MODE (integer_type_node), 1168 sjlj_fc_call_site_ofs); 1169 emit_move_insn (mem, gen_int_mode (this_call_site, GET_MODE (mem))); 1170 p = get_insns (); 1171 end_sequence (); 1172 1173 emit_insn_before (p, before); 1174 last_call_site = this_call_site; 1175 } 1176} 1177 1178/* Construct the SjLj_Function_Context. */ 1179 1180static void 1181sjlj_emit_function_enter (rtx_code_label *dispatch_label) 1182{ 1183 rtx_insn *fn_begin, *seq; 1184 rtx fc, mem; 1185 bool fn_begin_outside_block; 1186 rtx personality = get_personality_function (current_function_decl); 1187 1188 fc = crtl->eh.sjlj_fc; 1189 1190 start_sequence (); 1191 1192 /* We're storing this libcall's address into memory instead of 1193 calling it directly. Thus, we must call assemble_external_libcall 1194 here, as we can not depend on emit_library_call to do it for us. */ 1195 assemble_external_libcall (personality); 1196 mem = adjust_address (fc, Pmode, sjlj_fc_personality_ofs); 1197 emit_move_insn (mem, personality); 1198 1199 mem = adjust_address (fc, Pmode, sjlj_fc_lsda_ofs); 1200 if (crtl->uses_eh_lsda) 1201 { 1202 char buf[20]; 1203 rtx sym; 1204 1205 ASM_GENERATE_INTERNAL_LABEL (buf, "LLSDA", current_function_funcdef_no); 1206 sym = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)); 1207 SYMBOL_REF_FLAGS (sym) = SYMBOL_FLAG_LOCAL; 1208 emit_move_insn (mem, sym); 1209 } 1210 else 1211 emit_move_insn (mem, const0_rtx); 1212 1213 if (dispatch_label) 1214 { 1215#ifdef DONT_USE_BUILTIN_SETJMP 1216 rtx x; 1217 x = emit_library_call_value (setjmp_libfunc, NULL_RTX, LCT_RETURNS_TWICE, 1218 TYPE_MODE (integer_type_node), 1, 1219 plus_constant (Pmode, XEXP (fc, 0), 1220 sjlj_fc_jbuf_ofs), Pmode); 1221 1222 emit_cmp_and_jump_insns (x, const0_rtx, NE, 0, 1223 TYPE_MODE (integer_type_node), 0, 1224 dispatch_label, REG_BR_PROB_BASE / 100); 1225#else 1226 expand_builtin_setjmp_setup (plus_constant (Pmode, XEXP (fc, 0), 1227 sjlj_fc_jbuf_ofs), 1228 dispatch_label); 1229#endif 1230 } 1231 1232 emit_library_call (unwind_sjlj_register_libfunc, LCT_NORMAL, VOIDmode, 1233 1, XEXP (fc, 0), Pmode); 1234 1235 seq = get_insns (); 1236 end_sequence (); 1237 1238 /* ??? Instead of doing this at the beginning of the function, 1239 do this in a block that is at loop level 0 and dominates all 1240 can_throw_internal instructions. */ 1241 1242 fn_begin_outside_block = true; 1243 for (fn_begin = get_insns (); ; fn_begin = NEXT_INSN (fn_begin)) 1244 if (NOTE_P (fn_begin)) 1245 { 1246 if (NOTE_KIND (fn_begin) == NOTE_INSN_FUNCTION_BEG) 1247 break; 1248 else if (NOTE_INSN_BASIC_BLOCK_P (fn_begin)) 1249 fn_begin_outside_block = false; 1250 } 1251 1252 if (fn_begin_outside_block) 1253 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun))); 1254 else 1255 emit_insn_after (seq, fn_begin); 1256} 1257 1258/* Call back from expand_function_end to know where we should put 1259 the call to unwind_sjlj_unregister_libfunc if needed. */ 1260 1261void 1262sjlj_emit_function_exit_after (rtx_insn *after) 1263{ 1264 crtl->eh.sjlj_exit_after = after; 1265} 1266 1267static void 1268sjlj_emit_function_exit (void) 1269{ 1270 rtx_insn *seq, *insn; 1271 1272 start_sequence (); 1273 1274 emit_library_call (unwind_sjlj_unregister_libfunc, LCT_NORMAL, VOIDmode, 1275 1, XEXP (crtl->eh.sjlj_fc, 0), Pmode); 1276 1277 seq = get_insns (); 1278 end_sequence (); 1279 1280 /* ??? Really this can be done in any block at loop level 0 that 1281 post-dominates all can_throw_internal instructions. This is 1282 the last possible moment. */ 1283 1284 insn = crtl->eh.sjlj_exit_after; 1285 if (LABEL_P (insn)) 1286 insn = NEXT_INSN (insn); 1287 1288 emit_insn_after (seq, insn); 1289} 1290 1291static void 1292sjlj_emit_dispatch_table (rtx_code_label *dispatch_label, int num_dispatch) 1293{ 1294 machine_mode unwind_word_mode = targetm.unwind_word_mode (); 1295 machine_mode filter_mode = targetm.eh_return_filter_mode (); 1296 eh_landing_pad lp; 1297 rtx mem, fc, before, exc_ptr_reg, filter_reg; 1298 rtx_insn *seq; 1299 rtx first_reachable_label; 1300 basic_block bb; 1301 eh_region r; 1302 edge e; 1303 int i, disp_index; 1304 vec<tree> dispatch_labels = vNULL; 1305 1306 fc = crtl->eh.sjlj_fc; 1307 1308 start_sequence (); 1309 1310 emit_label (dispatch_label); 1311 1312#ifndef DONT_USE_BUILTIN_SETJMP 1313 expand_builtin_setjmp_receiver (dispatch_label); 1314 1315 /* The caller of expand_builtin_setjmp_receiver is responsible for 1316 making sure that the label doesn't vanish. The only other caller 1317 is the expander for __builtin_setjmp_receiver, which places this 1318 label on the nonlocal_goto_label list. Since we're modeling these 1319 CFG edges more exactly, we can use the forced_labels list instead. */ 1320 LABEL_PRESERVE_P (dispatch_label) = 1; 1321 forced_labels 1322 = gen_rtx_INSN_LIST (VOIDmode, dispatch_label, forced_labels); 1323#endif 1324 1325 /* Load up exc_ptr and filter values from the function context. */ 1326 mem = adjust_address (fc, unwind_word_mode, sjlj_fc_data_ofs); 1327 if (unwind_word_mode != ptr_mode) 1328 { 1329#ifdef POINTERS_EXTEND_UNSIGNED 1330 mem = convert_memory_address (ptr_mode, mem); 1331#else 1332 mem = convert_to_mode (ptr_mode, mem, 0); 1333#endif 1334 } 1335 exc_ptr_reg = force_reg (ptr_mode, mem); 1336 1337 mem = adjust_address (fc, unwind_word_mode, 1338 sjlj_fc_data_ofs + GET_MODE_SIZE (unwind_word_mode)); 1339 if (unwind_word_mode != filter_mode) 1340 mem = convert_to_mode (filter_mode, mem, 0); 1341 filter_reg = force_reg (filter_mode, mem); 1342 1343 /* Jump to one of the directly reachable regions. */ 1344 1345 disp_index = 0; 1346 first_reachable_label = NULL; 1347 1348 /* If there's exactly one call site in the function, don't bother 1349 generating a switch statement. */ 1350 if (num_dispatch > 1) 1351 dispatch_labels.create (num_dispatch); 1352 1353 for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i) 1354 if (lp && lp->post_landing_pad) 1355 { 1356 rtx_insn *seq2; 1357 rtx label; 1358 1359 start_sequence (); 1360 1361 lp->landing_pad = dispatch_label; 1362 1363 if (num_dispatch > 1) 1364 { 1365 tree t_label, case_elt, t; 1366 1367 t_label = create_artificial_label (UNKNOWN_LOCATION); 1368 t = build_int_cst (integer_type_node, disp_index); 1369 case_elt = build_case_label (t, NULL, t_label); 1370 dispatch_labels.quick_push (case_elt); 1371 label = label_rtx (t_label); 1372 } 1373 else 1374 label = gen_label_rtx (); 1375 1376 if (disp_index == 0) 1377 first_reachable_label = label; 1378 emit_label (label); 1379 1380 r = lp->region; 1381 if (r->exc_ptr_reg) 1382 emit_move_insn (r->exc_ptr_reg, exc_ptr_reg); 1383 if (r->filter_reg) 1384 emit_move_insn (r->filter_reg, filter_reg); 1385 1386 seq2 = get_insns (); 1387 end_sequence (); 1388 1389 before = label_rtx (lp->post_landing_pad); 1390 bb = emit_to_new_bb_before (seq2, before); 1391 e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU); 1392 e->count = bb->count; 1393 e->probability = REG_BR_PROB_BASE; 1394 if (current_loops) 1395 { 1396 struct loop *loop = bb->next_bb->loop_father; 1397 /* If we created a pre-header block, add the new block to the 1398 outer loop, otherwise to the loop itself. */ 1399 if (bb->next_bb == loop->header) 1400 add_bb_to_loop (bb, loop_outer (loop)); 1401 else 1402 add_bb_to_loop (bb, loop); 1403 /* ??? For multiple dispatches we will end up with edges 1404 from the loop tree root into this loop, making it a 1405 multiple-entry loop. Discard all affected loops. */ 1406 if (num_dispatch > 1) 1407 { 1408 for (loop = bb->loop_father; 1409 loop_outer (loop); loop = loop_outer (loop)) 1410 mark_loop_for_removal (loop); 1411 } 1412 } 1413 1414 disp_index++; 1415 } 1416 gcc_assert (disp_index == num_dispatch); 1417 1418 if (num_dispatch > 1) 1419 { 1420 rtx disp = adjust_address (fc, TYPE_MODE (integer_type_node), 1421 sjlj_fc_call_site_ofs); 1422 expand_sjlj_dispatch_table (disp, dispatch_labels); 1423 } 1424 1425 seq = get_insns (); 1426 end_sequence (); 1427 1428 bb = emit_to_new_bb_before (seq, first_reachable_label); 1429 if (num_dispatch == 1) 1430 { 1431 e = make_edge (bb, bb->next_bb, EDGE_FALLTHRU); 1432 e->count = bb->count; 1433 e->probability = REG_BR_PROB_BASE; 1434 if (current_loops) 1435 { 1436 struct loop *loop = bb->next_bb->loop_father; 1437 /* If we created a pre-header block, add the new block to the 1438 outer loop, otherwise to the loop itself. */ 1439 if (bb->next_bb == loop->header) 1440 add_bb_to_loop (bb, loop_outer (loop)); 1441 else 1442 add_bb_to_loop (bb, loop); 1443 } 1444 } 1445 else 1446 { 1447 /* We are not wiring up edges here, but as the dispatcher call 1448 is at function begin simply associate the block with the 1449 outermost (non-)loop. */ 1450 if (current_loops) 1451 add_bb_to_loop (bb, current_loops->tree_root); 1452 } 1453} 1454 1455static void 1456sjlj_build_landing_pads (void) 1457{ 1458 int num_dispatch; 1459 1460 num_dispatch = vec_safe_length (cfun->eh->lp_array); 1461 if (num_dispatch == 0) 1462 return; 1463 sjlj_lp_call_site_index.safe_grow_cleared (num_dispatch); 1464 1465 num_dispatch = sjlj_assign_call_site_values (); 1466 if (num_dispatch > 0) 1467 { 1468 rtx_code_label *dispatch_label = gen_label_rtx (); 1469 int align = STACK_SLOT_ALIGNMENT (sjlj_fc_type_node, 1470 TYPE_MODE (sjlj_fc_type_node), 1471 TYPE_ALIGN (sjlj_fc_type_node)); 1472 crtl->eh.sjlj_fc 1473 = assign_stack_local (TYPE_MODE (sjlj_fc_type_node), 1474 int_size_in_bytes (sjlj_fc_type_node), 1475 align); 1476 1477 sjlj_mark_call_sites (); 1478 sjlj_emit_function_enter (dispatch_label); 1479 sjlj_emit_dispatch_table (dispatch_label, num_dispatch); 1480 sjlj_emit_function_exit (); 1481 } 1482 1483 /* If we do not have any landing pads, we may still need to register a 1484 personality routine and (empty) LSDA to handle must-not-throw regions. */ 1485 else if (function_needs_eh_personality (cfun) != eh_personality_none) 1486 { 1487 int align = STACK_SLOT_ALIGNMENT (sjlj_fc_type_node, 1488 TYPE_MODE (sjlj_fc_type_node), 1489 TYPE_ALIGN (sjlj_fc_type_node)); 1490 crtl->eh.sjlj_fc 1491 = assign_stack_local (TYPE_MODE (sjlj_fc_type_node), 1492 int_size_in_bytes (sjlj_fc_type_node), 1493 align); 1494 1495 sjlj_mark_call_sites (); 1496 sjlj_emit_function_enter (NULL); 1497 sjlj_emit_function_exit (); 1498 } 1499 1500 sjlj_lp_call_site_index.release (); 1501} 1502 1503/* After initial rtl generation, call back to finish generating 1504 exception support code. */ 1505 1506void 1507finish_eh_generation (void) 1508{ 1509 basic_block bb; 1510 1511 /* Construct the landing pads. */ 1512 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) 1513 sjlj_build_landing_pads (); 1514 else 1515 dw2_build_landing_pads (); 1516 break_superblocks (); 1517 1518 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ 1519 /* Kludge for Alpha (see alpha_gp_save_rtx). */ 1520 || single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun))->insns.r) 1521 commit_edge_insertions (); 1522 1523 /* Redirect all EH edges from the post_landing_pad to the landing pad. */ 1524 FOR_EACH_BB_FN (bb, cfun) 1525 { 1526 eh_landing_pad lp; 1527 edge_iterator ei; 1528 edge e; 1529 1530 lp = get_eh_landing_pad_from_rtx (BB_END (bb)); 1531 1532 FOR_EACH_EDGE (e, ei, bb->succs) 1533 if (e->flags & EDGE_EH) 1534 break; 1535 1536 /* We should not have generated any new throwing insns during this 1537 pass, and we should not have lost any EH edges, so we only need 1538 to handle two cases here: 1539 (1) reachable handler and an existing edge to post-landing-pad, 1540 (2) no reachable handler and no edge. */ 1541 gcc_assert ((lp != NULL) == (e != NULL)); 1542 if (lp != NULL) 1543 { 1544 gcc_assert (BB_HEAD (e->dest) == label_rtx (lp->post_landing_pad)); 1545 1546 redirect_edge_succ (e, BLOCK_FOR_INSN (lp->landing_pad)); 1547 e->flags |= (CALL_P (BB_END (bb)) 1548 ? EDGE_ABNORMAL | EDGE_ABNORMAL_CALL 1549 : EDGE_ABNORMAL); 1550 } 1551 } 1552} 1553 1554/* This section handles removing dead code for flow. */ 1555 1556void 1557remove_eh_landing_pad (eh_landing_pad lp) 1558{ 1559 eh_landing_pad *pp; 1560 1561 for (pp = &lp->region->landing_pads; *pp != lp; pp = &(*pp)->next_lp) 1562 continue; 1563 *pp = lp->next_lp; 1564 1565 if (lp->post_landing_pad) 1566 EH_LANDING_PAD_NR (lp->post_landing_pad) = 0; 1567 (*cfun->eh->lp_array)[lp->index] = NULL; 1568} 1569 1570/* Splice the EH region at PP from the region tree. */ 1571 1572static void 1573remove_eh_handler_splicer (eh_region *pp) 1574{ 1575 eh_region region = *pp; 1576 eh_landing_pad lp; 1577 1578 for (lp = region->landing_pads; lp ; lp = lp->next_lp) 1579 { 1580 if (lp->post_landing_pad) 1581 EH_LANDING_PAD_NR (lp->post_landing_pad) = 0; 1582 (*cfun->eh->lp_array)[lp->index] = NULL; 1583 } 1584 1585 if (region->inner) 1586 { 1587 eh_region p, outer; 1588 outer = region->outer; 1589 1590 *pp = p = region->inner; 1591 do 1592 { 1593 p->outer = outer; 1594 pp = &p->next_peer; 1595 p = *pp; 1596 } 1597 while (p); 1598 } 1599 *pp = region->next_peer; 1600 1601 (*cfun->eh->region_array)[region->index] = NULL; 1602} 1603 1604/* Splice a single EH region REGION from the region tree. 1605 1606 To unlink REGION, we need to find the pointer to it with a relatively 1607 expensive search in REGION's outer region. If you are going to 1608 remove a number of handlers, using remove_unreachable_eh_regions may 1609 be a better option. */ 1610 1611void 1612remove_eh_handler (eh_region region) 1613{ 1614 eh_region *pp, *pp_start, p, outer; 1615 1616 outer = region->outer; 1617 if (outer) 1618 pp_start = &outer->inner; 1619 else 1620 pp_start = &cfun->eh->region_tree; 1621 for (pp = pp_start, p = *pp; p != region; pp = &p->next_peer, p = *pp) 1622 continue; 1623 1624 remove_eh_handler_splicer (pp); 1625} 1626 1627/* Worker for remove_unreachable_eh_regions. 1628 PP is a pointer to the region to start a region tree depth-first 1629 search from. R_REACHABLE is the set of regions that have to be 1630 preserved. */ 1631 1632static void 1633remove_unreachable_eh_regions_worker (eh_region *pp, sbitmap r_reachable) 1634{ 1635 while (*pp) 1636 { 1637 eh_region region = *pp; 1638 remove_unreachable_eh_regions_worker (®ion->inner, r_reachable); 1639 if (!bitmap_bit_p (r_reachable, region->index)) 1640 remove_eh_handler_splicer (pp); 1641 else 1642 pp = ®ion->next_peer; 1643 } 1644} 1645 1646/* Splice all EH regions *not* marked in R_REACHABLE from the region tree. 1647 Do this by traversing the EH tree top-down and splice out regions that 1648 are not marked. By removing regions from the leaves, we avoid costly 1649 searches in the region tree. */ 1650 1651void 1652remove_unreachable_eh_regions (sbitmap r_reachable) 1653{ 1654 remove_unreachable_eh_regions_worker (&cfun->eh->region_tree, r_reachable); 1655} 1656 1657/* Invokes CALLBACK for every exception handler landing pad label. 1658 Only used by reload hackery; should not be used by new code. */ 1659 1660void 1661for_each_eh_label (void (*callback) (rtx)) 1662{ 1663 eh_landing_pad lp; 1664 int i; 1665 1666 for (i = 1; vec_safe_iterate (cfun->eh->lp_array, i, &lp); ++i) 1667 { 1668 if (lp) 1669 { 1670 rtx lab = lp->landing_pad; 1671 if (lab && LABEL_P (lab)) 1672 (*callback) (lab); 1673 } 1674 } 1675} 1676 1677/* Create the REG_EH_REGION note for INSN, given its ECF_FLAGS for a 1678 call insn. 1679 1680 At the gimple level, we use LP_NR 1681 > 0 : The statement transfers to landing pad LP_NR 1682 = 0 : The statement is outside any EH region 1683 < 0 : The statement is within MUST_NOT_THROW region -LP_NR. 1684 1685 At the rtl level, we use LP_NR 1686 > 0 : The insn transfers to landing pad LP_NR 1687 = 0 : The insn cannot throw 1688 < 0 : The insn is within MUST_NOT_THROW region -LP_NR 1689 = INT_MIN : The insn cannot throw or execute a nonlocal-goto. 1690 missing note: The insn is outside any EH region. 1691 1692 ??? This difference probably ought to be avoided. We could stand 1693 to record nothrow for arbitrary gimple statements, and so avoid 1694 some moderately complex lookups in stmt_could_throw_p. Perhaps 1695 NOTHROW should be mapped on both sides to INT_MIN. Perhaps the 1696 no-nonlocal-goto property should be recorded elsewhere as a bit 1697 on the call_insn directly. Perhaps we should make more use of 1698 attaching the trees to call_insns (reachable via symbol_ref in 1699 direct call cases) and just pull the data out of the trees. */ 1700 1701void 1702make_reg_eh_region_note (rtx insn, int ecf_flags, int lp_nr) 1703{ 1704 rtx value; 1705 if (ecf_flags & ECF_NOTHROW) 1706 value = const0_rtx; 1707 else if (lp_nr != 0) 1708 value = GEN_INT (lp_nr); 1709 else 1710 return; 1711 add_reg_note (insn, REG_EH_REGION, value); 1712} 1713 1714/* Create a REG_EH_REGION note for a CALL_INSN that cannot throw 1715 nor perform a non-local goto. Replace the region note if it 1716 already exists. */ 1717 1718void 1719make_reg_eh_region_note_nothrow_nononlocal (rtx insn) 1720{ 1721 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); 1722 rtx intmin = GEN_INT (INT_MIN); 1723 1724 if (note != 0) 1725 XEXP (note, 0) = intmin; 1726 else 1727 add_reg_note (insn, REG_EH_REGION, intmin); 1728} 1729 1730/* Return true if INSN could throw, assuming no REG_EH_REGION note 1731 to the contrary. */ 1732 1733bool 1734insn_could_throw_p (const_rtx insn) 1735{ 1736 if (!flag_exceptions) 1737 return false; 1738 if (CALL_P (insn)) 1739 return true; 1740 if (INSN_P (insn) && cfun->can_throw_non_call_exceptions) 1741 return may_trap_p (PATTERN (insn)); 1742 return false; 1743} 1744 1745/* Copy an REG_EH_REGION note to each insn that might throw beginning 1746 at FIRST and ending at LAST. NOTE_OR_INSN is either the source insn 1747 to look for a note, or the note itself. */ 1748 1749void 1750copy_reg_eh_region_note_forward (rtx note_or_insn, rtx_insn *first, rtx last) 1751{ 1752 rtx_insn *insn; 1753 rtx note = note_or_insn; 1754 1755 if (INSN_P (note_or_insn)) 1756 { 1757 note = find_reg_note (note_or_insn, REG_EH_REGION, NULL_RTX); 1758 if (note == NULL) 1759 return; 1760 } 1761 note = XEXP (note, 0); 1762 1763 for (insn = first; insn != last ; insn = NEXT_INSN (insn)) 1764 if (!find_reg_note (insn, REG_EH_REGION, NULL_RTX) 1765 && insn_could_throw_p (insn)) 1766 add_reg_note (insn, REG_EH_REGION, note); 1767} 1768 1769/* Likewise, but iterate backward. */ 1770 1771void 1772copy_reg_eh_region_note_backward (rtx note_or_insn, rtx_insn *last, rtx first) 1773{ 1774 rtx_insn *insn; 1775 rtx note = note_or_insn; 1776 1777 if (INSN_P (note_or_insn)) 1778 { 1779 note = find_reg_note (note_or_insn, REG_EH_REGION, NULL_RTX); 1780 if (note == NULL) 1781 return; 1782 } 1783 note = XEXP (note, 0); 1784 1785 for (insn = last; insn != first; insn = PREV_INSN (insn)) 1786 if (insn_could_throw_p (insn)) 1787 add_reg_note (insn, REG_EH_REGION, note); 1788} 1789 1790 1791/* Extract all EH information from INSN. Return true if the insn 1792 was marked NOTHROW. */ 1793 1794static bool 1795get_eh_region_and_lp_from_rtx (const_rtx insn, eh_region *pr, 1796 eh_landing_pad *plp) 1797{ 1798 eh_landing_pad lp = NULL; 1799 eh_region r = NULL; 1800 bool ret = false; 1801 rtx note; 1802 int lp_nr; 1803 1804 if (! INSN_P (insn)) 1805 goto egress; 1806 1807 if (NONJUMP_INSN_P (insn) 1808 && GET_CODE (PATTERN (insn)) == SEQUENCE) 1809 insn = XVECEXP (PATTERN (insn), 0, 0); 1810 1811 note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); 1812 if (!note) 1813 { 1814 ret = !insn_could_throw_p (insn); 1815 goto egress; 1816 } 1817 1818 lp_nr = INTVAL (XEXP (note, 0)); 1819 if (lp_nr == 0 || lp_nr == INT_MIN) 1820 { 1821 ret = true; 1822 goto egress; 1823 } 1824 1825 if (lp_nr < 0) 1826 r = (*cfun->eh->region_array)[-lp_nr]; 1827 else 1828 { 1829 lp = (*cfun->eh->lp_array)[lp_nr]; 1830 r = lp->region; 1831 } 1832 1833 egress: 1834 *plp = lp; 1835 *pr = r; 1836 return ret; 1837} 1838 1839/* Return the landing pad to which INSN may go, or NULL if it does not 1840 have a reachable landing pad within this function. */ 1841 1842eh_landing_pad 1843get_eh_landing_pad_from_rtx (const_rtx insn) 1844{ 1845 eh_landing_pad lp; 1846 eh_region r; 1847 1848 get_eh_region_and_lp_from_rtx (insn, &r, &lp); 1849 return lp; 1850} 1851 1852/* Return the region to which INSN may go, or NULL if it does not 1853 have a reachable region within this function. */ 1854 1855eh_region 1856get_eh_region_from_rtx (const_rtx insn) 1857{ 1858 eh_landing_pad lp; 1859 eh_region r; 1860 1861 get_eh_region_and_lp_from_rtx (insn, &r, &lp); 1862 return r; 1863} 1864 1865/* Return true if INSN throws and is caught by something in this function. */ 1866 1867bool 1868can_throw_internal (const_rtx insn) 1869{ 1870 return get_eh_landing_pad_from_rtx (insn) != NULL; 1871} 1872 1873/* Return true if INSN throws and escapes from the current function. */ 1874 1875bool 1876can_throw_external (const_rtx insn) 1877{ 1878 eh_landing_pad lp; 1879 eh_region r; 1880 bool nothrow; 1881 1882 if (! INSN_P (insn)) 1883 return false; 1884 1885 if (NONJUMP_INSN_P (insn) 1886 && GET_CODE (PATTERN (insn)) == SEQUENCE) 1887 { 1888 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn)); 1889 int i, n = seq->len (); 1890 1891 for (i = 0; i < n; i++) 1892 if (can_throw_external (seq->element (i))) 1893 return true; 1894 1895 return false; 1896 } 1897 1898 nothrow = get_eh_region_and_lp_from_rtx (insn, &r, &lp); 1899 1900 /* If we can't throw, we obviously can't throw external. */ 1901 if (nothrow) 1902 return false; 1903 1904 /* If we have an internal landing pad, then we're not external. */ 1905 if (lp != NULL) 1906 return false; 1907 1908 /* If we're not within an EH region, then we are external. */ 1909 if (r == NULL) 1910 return true; 1911 1912 /* The only thing that ought to be left is MUST_NOT_THROW regions, 1913 which don't always have landing pads. */ 1914 gcc_assert (r->type == ERT_MUST_NOT_THROW); 1915 return false; 1916} 1917 1918/* Return true if INSN cannot throw at all. */ 1919 1920bool 1921insn_nothrow_p (const_rtx insn) 1922{ 1923 eh_landing_pad lp; 1924 eh_region r; 1925 1926 if (! INSN_P (insn)) 1927 return true; 1928 1929 if (NONJUMP_INSN_P (insn) 1930 && GET_CODE (PATTERN (insn)) == SEQUENCE) 1931 { 1932 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn)); 1933 int i, n = seq->len (); 1934 1935 for (i = 0; i < n; i++) 1936 if (!insn_nothrow_p (seq->element (i))) 1937 return false; 1938 1939 return true; 1940 } 1941 1942 return get_eh_region_and_lp_from_rtx (insn, &r, &lp); 1943} 1944 1945/* Return true if INSN can perform a non-local goto. */ 1946/* ??? This test is here in this file because it (ab)uses REG_EH_REGION. */ 1947 1948bool 1949can_nonlocal_goto (const_rtx insn) 1950{ 1951 if (nonlocal_goto_handler_labels && CALL_P (insn)) 1952 { 1953 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); 1954 if (!note || INTVAL (XEXP (note, 0)) != INT_MIN) 1955 return true; 1956 } 1957 return false; 1958} 1959 1960/* Set TREE_NOTHROW and crtl->all_throwers_are_sibcalls. */ 1961 1962static unsigned int 1963set_nothrow_function_flags (void) 1964{ 1965 rtx_insn *insn; 1966 1967 crtl->nothrow = 1; 1968 1969 /* Assume crtl->all_throwers_are_sibcalls until we encounter 1970 something that can throw an exception. We specifically exempt 1971 CALL_INSNs that are SIBLING_CALL_P, as these are really jumps, 1972 and can't throw. Most CALL_INSNs are not SIBLING_CALL_P, so this 1973 is optimistic. */ 1974 1975 crtl->all_throwers_are_sibcalls = 1; 1976 1977 /* If we don't know that this implementation of the function will 1978 actually be used, then we must not set TREE_NOTHROW, since 1979 callers must not assume that this function does not throw. */ 1980 if (TREE_NOTHROW (current_function_decl)) 1981 return 0; 1982 1983 if (! flag_exceptions) 1984 return 0; 1985 1986 for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) 1987 if (can_throw_external (insn)) 1988 { 1989 crtl->nothrow = 0; 1990 1991 if (!CALL_P (insn) || !SIBLING_CALL_P (insn)) 1992 { 1993 crtl->all_throwers_are_sibcalls = 0; 1994 return 0; 1995 } 1996 } 1997 1998 if (crtl->nothrow 1999 && (cgraph_node::get (current_function_decl)->get_availability () 2000 >= AVAIL_AVAILABLE)) 2001 { 2002 struct cgraph_node *node = cgraph_node::get (current_function_decl); 2003 struct cgraph_edge *e; 2004 for (e = node->callers; e; e = e->next_caller) 2005 e->can_throw_external = false; 2006 node->set_nothrow_flag (true); 2007 2008 if (dump_file) 2009 fprintf (dump_file, "Marking function nothrow: %s\n\n", 2010 current_function_name ()); 2011 } 2012 return 0; 2013} 2014 2015namespace { 2016 2017const pass_data pass_data_set_nothrow_function_flags = 2018{ 2019 RTL_PASS, /* type */ 2020 "nothrow", /* name */ 2021 OPTGROUP_NONE, /* optinfo_flags */ 2022 TV_NONE, /* tv_id */ 2023 0, /* properties_required */ 2024 0, /* properties_provided */ 2025 0, /* properties_destroyed */ 2026 0, /* todo_flags_start */ 2027 0, /* todo_flags_finish */ 2028}; 2029 2030class pass_set_nothrow_function_flags : public rtl_opt_pass 2031{ 2032public: 2033 pass_set_nothrow_function_flags (gcc::context *ctxt) 2034 : rtl_opt_pass (pass_data_set_nothrow_function_flags, ctxt) 2035 {} 2036 2037 /* opt_pass methods: */ 2038 virtual unsigned int execute (function *) 2039 { 2040 return set_nothrow_function_flags (); 2041 } 2042 2043}; // class pass_set_nothrow_function_flags 2044 2045} // anon namespace 2046 2047rtl_opt_pass * 2048make_pass_set_nothrow_function_flags (gcc::context *ctxt) 2049{ 2050 return new pass_set_nothrow_function_flags (ctxt); 2051} 2052 2053 2054/* Various hooks for unwind library. */ 2055 2056/* Expand the EH support builtin functions: 2057 __builtin_eh_pointer and __builtin_eh_filter. */ 2058 2059static eh_region 2060expand_builtin_eh_common (tree region_nr_t) 2061{ 2062 HOST_WIDE_INT region_nr; 2063 eh_region region; 2064 2065 gcc_assert (tree_fits_shwi_p (region_nr_t)); 2066 region_nr = tree_to_shwi (region_nr_t); 2067 2068 region = (*cfun->eh->region_array)[region_nr]; 2069 2070 /* ??? We shouldn't have been able to delete a eh region without 2071 deleting all the code that depended on it. */ 2072 gcc_assert (region != NULL); 2073 2074 return region; 2075} 2076 2077/* Expand to the exc_ptr value from the given eh region. */ 2078 2079rtx 2080expand_builtin_eh_pointer (tree exp) 2081{ 2082 eh_region region 2083 = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0)); 2084 if (region->exc_ptr_reg == NULL) 2085 region->exc_ptr_reg = gen_reg_rtx (ptr_mode); 2086 return region->exc_ptr_reg; 2087} 2088 2089/* Expand to the filter value from the given eh region. */ 2090 2091rtx 2092expand_builtin_eh_filter (tree exp) 2093{ 2094 eh_region region 2095 = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0)); 2096 if (region->filter_reg == NULL) 2097 region->filter_reg = gen_reg_rtx (targetm.eh_return_filter_mode ()); 2098 return region->filter_reg; 2099} 2100 2101/* Copy the exc_ptr and filter values from one landing pad's registers 2102 to another. This is used to inline the resx statement. */ 2103 2104rtx 2105expand_builtin_eh_copy_values (tree exp) 2106{ 2107 eh_region dst 2108 = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 0)); 2109 eh_region src 2110 = expand_builtin_eh_common (CALL_EXPR_ARG (exp, 1)); 2111 machine_mode fmode = targetm.eh_return_filter_mode (); 2112 2113 if (dst->exc_ptr_reg == NULL) 2114 dst->exc_ptr_reg = gen_reg_rtx (ptr_mode); 2115 if (src->exc_ptr_reg == NULL) 2116 src->exc_ptr_reg = gen_reg_rtx (ptr_mode); 2117 2118 if (dst->filter_reg == NULL) 2119 dst->filter_reg = gen_reg_rtx (fmode); 2120 if (src->filter_reg == NULL) 2121 src->filter_reg = gen_reg_rtx (fmode); 2122 2123 emit_move_insn (dst->exc_ptr_reg, src->exc_ptr_reg); 2124 emit_move_insn (dst->filter_reg, src->filter_reg); 2125 2126 return const0_rtx; 2127} 2128 2129/* Do any necessary initialization to access arbitrary stack frames. 2130 On the SPARC, this means flushing the register windows. */ 2131 2132void 2133expand_builtin_unwind_init (void) 2134{ 2135 /* Set this so all the registers get saved in our frame; we need to be 2136 able to copy the saved values for any registers from frames we unwind. */ 2137 crtl->saves_all_registers = 1; 2138 2139#ifdef SETUP_FRAME_ADDRESSES 2140 SETUP_FRAME_ADDRESSES (); 2141#endif 2142} 2143 2144/* Map a non-negative number to an eh return data register number; expands 2145 to -1 if no return data register is associated with the input number. 2146 At least the inputs 0 and 1 must be mapped; the target may provide more. */ 2147 2148rtx 2149expand_builtin_eh_return_data_regno (tree exp) 2150{ 2151 tree which = CALL_EXPR_ARG (exp, 0); 2152 unsigned HOST_WIDE_INT iwhich; 2153 2154 if (TREE_CODE (which) != INTEGER_CST) 2155 { 2156 error ("argument of %<__builtin_eh_return_regno%> must be constant"); 2157 return constm1_rtx; 2158 } 2159 2160 iwhich = tree_to_uhwi (which); 2161 iwhich = EH_RETURN_DATA_REGNO (iwhich); 2162 if (iwhich == INVALID_REGNUM) 2163 return constm1_rtx; 2164 2165#ifdef DWARF_FRAME_REGNUM 2166 iwhich = DWARF_FRAME_REGNUM (iwhich); 2167#else 2168 iwhich = DBX_REGISTER_NUMBER (iwhich); 2169#endif 2170 2171 return GEN_INT (iwhich); 2172} 2173 2174/* Given a value extracted from the return address register or stack slot, 2175 return the actual address encoded in that value. */ 2176 2177rtx 2178expand_builtin_extract_return_addr (tree addr_tree) 2179{ 2180 rtx addr = expand_expr (addr_tree, NULL_RTX, Pmode, EXPAND_NORMAL); 2181 2182 if (GET_MODE (addr) != Pmode 2183 && GET_MODE (addr) != VOIDmode) 2184 { 2185#ifdef POINTERS_EXTEND_UNSIGNED 2186 addr = convert_memory_address (Pmode, addr); 2187#else 2188 addr = convert_to_mode (Pmode, addr, 0); 2189#endif 2190 } 2191 2192 /* First mask out any unwanted bits. */ 2193#ifdef MASK_RETURN_ADDR 2194 expand_and (Pmode, addr, MASK_RETURN_ADDR, addr); 2195#endif 2196 2197 /* Then adjust to find the real return address. */ 2198#if defined (RETURN_ADDR_OFFSET) 2199 addr = plus_constant (Pmode, addr, RETURN_ADDR_OFFSET); 2200#endif 2201 2202 return addr; 2203} 2204 2205/* Given an actual address in addr_tree, do any necessary encoding 2206 and return the value to be stored in the return address register or 2207 stack slot so the epilogue will return to that address. */ 2208 2209rtx 2210expand_builtin_frob_return_addr (tree addr_tree) 2211{ 2212 rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, EXPAND_NORMAL); 2213 2214 addr = convert_memory_address (Pmode, addr); 2215 2216#ifdef RETURN_ADDR_OFFSET 2217 addr = force_reg (Pmode, addr); 2218 addr = plus_constant (Pmode, addr, -RETURN_ADDR_OFFSET); 2219#endif 2220 2221 return addr; 2222} 2223 2224/* Set up the epilogue with the magic bits we'll need to return to the 2225 exception handler. */ 2226 2227void 2228expand_builtin_eh_return (tree stackadj_tree ATTRIBUTE_UNUSED, 2229 tree handler_tree) 2230{ 2231 rtx tmp; 2232 2233#ifdef EH_RETURN_STACKADJ_RTX 2234 tmp = expand_expr (stackadj_tree, crtl->eh.ehr_stackadj, 2235 VOIDmode, EXPAND_NORMAL); 2236 tmp = convert_memory_address (Pmode, tmp); 2237 if (!crtl->eh.ehr_stackadj) 2238 crtl->eh.ehr_stackadj = copy_addr_to_reg (tmp); 2239 else if (tmp != crtl->eh.ehr_stackadj) 2240 emit_move_insn (crtl->eh.ehr_stackadj, tmp); 2241#endif 2242 2243 tmp = expand_expr (handler_tree, crtl->eh.ehr_handler, 2244 VOIDmode, EXPAND_NORMAL); 2245 tmp = convert_memory_address (Pmode, tmp); 2246 if (!crtl->eh.ehr_handler) 2247 crtl->eh.ehr_handler = copy_addr_to_reg (tmp); 2248 else if (tmp != crtl->eh.ehr_handler) 2249 emit_move_insn (crtl->eh.ehr_handler, tmp); 2250 2251 if (!crtl->eh.ehr_label) 2252 crtl->eh.ehr_label = gen_label_rtx (); 2253 emit_jump (crtl->eh.ehr_label); 2254} 2255 2256/* Expand __builtin_eh_return. This exit path from the function loads up 2257 the eh return data registers, adjusts the stack, and branches to a 2258 given PC other than the normal return address. */ 2259 2260void 2261expand_eh_return (void) 2262{ 2263 rtx_code_label *around_label; 2264 2265 if (! crtl->eh.ehr_label) 2266 return; 2267 2268 crtl->calls_eh_return = 1; 2269 2270#ifdef EH_RETURN_STACKADJ_RTX 2271 emit_move_insn (EH_RETURN_STACKADJ_RTX, const0_rtx); 2272#endif 2273 2274 around_label = gen_label_rtx (); 2275 emit_jump (around_label); 2276 2277 emit_label (crtl->eh.ehr_label); 2278 clobber_return_register (); 2279 2280#ifdef EH_RETURN_STACKADJ_RTX 2281 emit_move_insn (EH_RETURN_STACKADJ_RTX, crtl->eh.ehr_stackadj); 2282#endif 2283 2284#ifdef HAVE_eh_return 2285 if (HAVE_eh_return) 2286 emit_insn (gen_eh_return (crtl->eh.ehr_handler)); 2287 else 2288#endif 2289 { 2290#ifdef EH_RETURN_HANDLER_RTX 2291 emit_move_insn (EH_RETURN_HANDLER_RTX, crtl->eh.ehr_handler); 2292#else 2293 error ("__builtin_eh_return not supported on this target"); 2294#endif 2295 } 2296 2297 emit_label (around_label); 2298} 2299 2300/* Convert a ptr_mode address ADDR_TREE to a Pmode address controlled by 2301 POINTERS_EXTEND_UNSIGNED and return it. */ 2302 2303rtx 2304expand_builtin_extend_pointer (tree addr_tree) 2305{ 2306 rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, EXPAND_NORMAL); 2307 int extend; 2308 2309#ifdef POINTERS_EXTEND_UNSIGNED 2310 extend = POINTERS_EXTEND_UNSIGNED; 2311#else 2312 /* The previous EH code did an unsigned extend by default, so we do this also 2313 for consistency. */ 2314 extend = 1; 2315#endif 2316 2317 return convert_modes (targetm.unwind_word_mode (), ptr_mode, addr, extend); 2318} 2319 2320static int 2321add_action_record (action_hash_type *ar_hash, int filter, int next) 2322{ 2323 struct action_record **slot, *new_ar, tmp; 2324 2325 tmp.filter = filter; 2326 tmp.next = next; 2327 slot = ar_hash->find_slot (&tmp, INSERT); 2328 2329 if ((new_ar = *slot) == NULL) 2330 { 2331 new_ar = XNEW (struct action_record); 2332 new_ar->offset = crtl->eh.action_record_data->length () + 1; 2333 new_ar->filter = filter; 2334 new_ar->next = next; 2335 *slot = new_ar; 2336 2337 /* The filter value goes in untouched. The link to the next 2338 record is a "self-relative" byte offset, or zero to indicate 2339 that there is no next record. So convert the absolute 1 based 2340 indices we've been carrying around into a displacement. */ 2341 2342 push_sleb128 (&crtl->eh.action_record_data, filter); 2343 if (next) 2344 next -= crtl->eh.action_record_data->length () + 1; 2345 push_sleb128 (&crtl->eh.action_record_data, next); 2346 } 2347 2348 return new_ar->offset; 2349} 2350 2351static int 2352collect_one_action_chain (action_hash_type *ar_hash, eh_region region) 2353{ 2354 int next; 2355 2356 /* If we've reached the top of the region chain, then we have 2357 no actions, and require no landing pad. */ 2358 if (region == NULL) 2359 return -1; 2360 2361 switch (region->type) 2362 { 2363 case ERT_CLEANUP: 2364 { 2365 eh_region r; 2366 /* A cleanup adds a zero filter to the beginning of the chain, but 2367 there are special cases to look out for. If there are *only* 2368 cleanups along a path, then it compresses to a zero action. 2369 Further, if there are multiple cleanups along a path, we only 2370 need to represent one of them, as that is enough to trigger 2371 entry to the landing pad at runtime. */ 2372 next = collect_one_action_chain (ar_hash, region->outer); 2373 if (next <= 0) 2374 return 0; 2375 for (r = region->outer; r ; r = r->outer) 2376 if (r->type == ERT_CLEANUP) 2377 return next; 2378 return add_action_record (ar_hash, 0, next); 2379 } 2380 2381 case ERT_TRY: 2382 { 2383 eh_catch c; 2384 2385 /* Process the associated catch regions in reverse order. 2386 If there's a catch-all handler, then we don't need to 2387 search outer regions. Use a magic -3 value to record 2388 that we haven't done the outer search. */ 2389 next = -3; 2390 for (c = region->u.eh_try.last_catch; c ; c = c->prev_catch) 2391 { 2392 if (c->type_list == NULL) 2393 { 2394 /* Retrieve the filter from the head of the filter list 2395 where we have stored it (see assign_filter_values). */ 2396 int filter = TREE_INT_CST_LOW (TREE_VALUE (c->filter_list)); 2397 next = add_action_record (ar_hash, filter, 0); 2398 } 2399 else 2400 { 2401 /* Once the outer search is done, trigger an action record for 2402 each filter we have. */ 2403 tree flt_node; 2404 2405 if (next == -3) 2406 { 2407 next = collect_one_action_chain (ar_hash, region->outer); 2408 2409 /* If there is no next action, terminate the chain. */ 2410 if (next == -1) 2411 next = 0; 2412 /* If all outer actions are cleanups or must_not_throw, 2413 we'll have no action record for it, since we had wanted 2414 to encode these states in the call-site record directly. 2415 Add a cleanup action to the chain to catch these. */ 2416 else if (next <= 0) 2417 next = add_action_record (ar_hash, 0, 0); 2418 } 2419 2420 flt_node = c->filter_list; 2421 for (; flt_node; flt_node = TREE_CHAIN (flt_node)) 2422 { 2423 int filter = TREE_INT_CST_LOW (TREE_VALUE (flt_node)); 2424 next = add_action_record (ar_hash, filter, next); 2425 } 2426 } 2427 } 2428 return next; 2429 } 2430 2431 case ERT_ALLOWED_EXCEPTIONS: 2432 /* An exception specification adds its filter to the 2433 beginning of the chain. */ 2434 next = collect_one_action_chain (ar_hash, region->outer); 2435 2436 /* If there is no next action, terminate the chain. */ 2437 if (next == -1) 2438 next = 0; 2439 /* If all outer actions are cleanups or must_not_throw, 2440 we'll have no action record for it, since we had wanted 2441 to encode these states in the call-site record directly. 2442 Add a cleanup action to the chain to catch these. */ 2443 else if (next <= 0) 2444 next = add_action_record (ar_hash, 0, 0); 2445 2446 return add_action_record (ar_hash, region->u.allowed.filter, next); 2447 2448 case ERT_MUST_NOT_THROW: 2449 /* A must-not-throw region with no inner handlers or cleanups 2450 requires no call-site entry. Note that this differs from 2451 the no handler or cleanup case in that we do require an lsda 2452 to be generated. Return a magic -2 value to record this. */ 2453 return -2; 2454 } 2455 2456 gcc_unreachable (); 2457} 2458 2459static int 2460add_call_site (rtx landing_pad, int action, int section) 2461{ 2462 call_site_record record; 2463 2464 record = ggc_alloc<call_site_record_d> (); 2465 record->landing_pad = landing_pad; 2466 record->action = action; 2467 2468 vec_safe_push (crtl->eh.call_site_record_v[section], record); 2469 2470 return call_site_base + crtl->eh.call_site_record_v[section]->length () - 1; 2471} 2472 2473static rtx_note * 2474emit_note_eh_region_end (rtx_insn *insn) 2475{ 2476 rtx_insn *next = NEXT_INSN (insn); 2477 2478 /* Make sure we do not split a call and its corresponding 2479 CALL_ARG_LOCATION note. */ 2480 if (next && NOTE_P (next) 2481 && NOTE_KIND (next) == NOTE_INSN_CALL_ARG_LOCATION) 2482 insn = next; 2483 2484 return emit_note_after (NOTE_INSN_EH_REGION_END, insn); 2485} 2486 2487/* Turn REG_EH_REGION notes back into NOTE_INSN_EH_REGION notes. 2488 The new note numbers will not refer to region numbers, but 2489 instead to call site entries. */ 2490 2491static unsigned int 2492convert_to_eh_region_ranges (void) 2493{ 2494 rtx insn; 2495 rtx_insn *iter; 2496 rtx_note *note; 2497 action_hash_type ar_hash (31); 2498 int last_action = -3; 2499 rtx_insn *last_action_insn = NULL; 2500 rtx last_landing_pad = NULL_RTX; 2501 rtx_insn *first_no_action_insn = NULL; 2502 int call_site = 0; 2503 int cur_sec = 0; 2504 rtx section_switch_note = NULL_RTX; 2505 rtx_insn *first_no_action_insn_before_switch = NULL; 2506 rtx_insn *last_no_action_insn_before_switch = NULL; 2507 int saved_call_site_base = call_site_base; 2508 2509 vec_alloc (crtl->eh.action_record_data, 64); 2510 2511 for (iter = get_insns (); iter ; iter = NEXT_INSN (iter)) 2512 if (INSN_P (iter)) 2513 { 2514 eh_landing_pad lp; 2515 eh_region region; 2516 bool nothrow; 2517 int this_action; 2518 rtx this_landing_pad; 2519 2520 insn = iter; 2521 if (NONJUMP_INSN_P (insn) 2522 && GET_CODE (PATTERN (insn)) == SEQUENCE) 2523 insn = XVECEXP (PATTERN (insn), 0, 0); 2524 2525 nothrow = get_eh_region_and_lp_from_rtx (insn, ®ion, &lp); 2526 if (nothrow) 2527 continue; 2528 if (region) 2529 this_action = collect_one_action_chain (&ar_hash, region); 2530 else 2531 this_action = -1; 2532 2533 /* Existence of catch handlers, or must-not-throw regions 2534 implies that an lsda is needed (even if empty). */ 2535 if (this_action != -1) 2536 crtl->uses_eh_lsda = 1; 2537 2538 /* Delay creation of region notes for no-action regions 2539 until we're sure that an lsda will be required. */ 2540 else if (last_action == -3) 2541 { 2542 first_no_action_insn = iter; 2543 last_action = -1; 2544 } 2545 2546 if (this_action >= 0) 2547 this_landing_pad = lp->landing_pad; 2548 else 2549 this_landing_pad = NULL_RTX; 2550 2551 /* Differing actions or landing pads implies a change in call-site 2552 info, which implies some EH_REGION note should be emitted. */ 2553 if (last_action != this_action 2554 || last_landing_pad != this_landing_pad) 2555 { 2556 /* If there is a queued no-action region in the other section 2557 with hot/cold partitioning, emit it now. */ 2558 if (first_no_action_insn_before_switch) 2559 { 2560 gcc_assert (this_action != -1 2561 && last_action == (first_no_action_insn 2562 ? -1 : -3)); 2563 call_site = add_call_site (NULL_RTX, 0, 0); 2564 note = emit_note_before (NOTE_INSN_EH_REGION_BEG, 2565 first_no_action_insn_before_switch); 2566 NOTE_EH_HANDLER (note) = call_site; 2567 note 2568 = emit_note_eh_region_end (last_no_action_insn_before_switch); 2569 NOTE_EH_HANDLER (note) = call_site; 2570 gcc_assert (last_action != -3 2571 || (last_action_insn 2572 == last_no_action_insn_before_switch)); 2573 first_no_action_insn_before_switch = NULL; 2574 last_no_action_insn_before_switch = NULL; 2575 call_site_base++; 2576 } 2577 /* If we'd not seen a previous action (-3) or the previous 2578 action was must-not-throw (-2), then we do not need an 2579 end note. */ 2580 if (last_action >= -1) 2581 { 2582 /* If we delayed the creation of the begin, do it now. */ 2583 if (first_no_action_insn) 2584 { 2585 call_site = add_call_site (NULL_RTX, 0, cur_sec); 2586 note = emit_note_before (NOTE_INSN_EH_REGION_BEG, 2587 first_no_action_insn); 2588 NOTE_EH_HANDLER (note) = call_site; 2589 first_no_action_insn = NULL; 2590 } 2591 2592 note = emit_note_eh_region_end (last_action_insn); 2593 NOTE_EH_HANDLER (note) = call_site; 2594 } 2595 2596 /* If the new action is must-not-throw, then no region notes 2597 are created. */ 2598 if (this_action >= -1) 2599 { 2600 call_site = add_call_site (this_landing_pad, 2601 this_action < 0 ? 0 : this_action, 2602 cur_sec); 2603 note = emit_note_before (NOTE_INSN_EH_REGION_BEG, iter); 2604 NOTE_EH_HANDLER (note) = call_site; 2605 } 2606 2607 last_action = this_action; 2608 last_landing_pad = this_landing_pad; 2609 } 2610 last_action_insn = iter; 2611 } 2612 else if (NOTE_P (iter) 2613 && NOTE_KIND (iter) == NOTE_INSN_SWITCH_TEXT_SECTIONS) 2614 { 2615 gcc_assert (section_switch_note == NULL_RTX); 2616 gcc_assert (flag_reorder_blocks_and_partition); 2617 section_switch_note = iter; 2618 if (first_no_action_insn) 2619 { 2620 first_no_action_insn_before_switch = first_no_action_insn; 2621 last_no_action_insn_before_switch = last_action_insn; 2622 first_no_action_insn = NULL; 2623 gcc_assert (last_action == -1); 2624 last_action = -3; 2625 } 2626 /* Force closing of current EH region before section switch and 2627 opening a new one afterwards. */ 2628 else if (last_action != -3) 2629 last_landing_pad = pc_rtx; 2630 if (crtl->eh.call_site_record_v[cur_sec]) 2631 call_site_base += crtl->eh.call_site_record_v[cur_sec]->length (); 2632 cur_sec++; 2633 gcc_assert (crtl->eh.call_site_record_v[cur_sec] == NULL); 2634 vec_alloc (crtl->eh.call_site_record_v[cur_sec], 10); 2635 } 2636 2637 if (last_action >= -1 && ! first_no_action_insn) 2638 { 2639 note = emit_note_eh_region_end (last_action_insn); 2640 NOTE_EH_HANDLER (note) = call_site; 2641 } 2642 2643 call_site_base = saved_call_site_base; 2644 2645 return 0; 2646} 2647 2648namespace { 2649 2650const pass_data pass_data_convert_to_eh_region_ranges = 2651{ 2652 RTL_PASS, /* type */ 2653 "eh_ranges", /* name */ 2654 OPTGROUP_NONE, /* optinfo_flags */ 2655 TV_NONE, /* tv_id */ 2656 0, /* properties_required */ 2657 0, /* properties_provided */ 2658 0, /* properties_destroyed */ 2659 0, /* todo_flags_start */ 2660 0, /* todo_flags_finish */ 2661}; 2662 2663class pass_convert_to_eh_region_ranges : public rtl_opt_pass 2664{ 2665public: 2666 pass_convert_to_eh_region_ranges (gcc::context *ctxt) 2667 : rtl_opt_pass (pass_data_convert_to_eh_region_ranges, ctxt) 2668 {} 2669 2670 /* opt_pass methods: */ 2671 virtual bool gate (function *); 2672 virtual unsigned int execute (function *) 2673 { 2674 return convert_to_eh_region_ranges (); 2675 } 2676 2677}; // class pass_convert_to_eh_region_ranges 2678 2679bool 2680pass_convert_to_eh_region_ranges::gate (function *) 2681{ 2682 /* Nothing to do for SJLJ exceptions or if no regions created. */ 2683 if (cfun->eh->region_tree == NULL) 2684 return false; 2685 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) 2686 return false; 2687 return true; 2688} 2689 2690} // anon namespace 2691 2692rtl_opt_pass * 2693make_pass_convert_to_eh_region_ranges (gcc::context *ctxt) 2694{ 2695 return new pass_convert_to_eh_region_ranges (ctxt); 2696} 2697 2698static void 2699push_uleb128 (vec<uchar, va_gc> **data_area, unsigned int value) 2700{ 2701 do 2702 { 2703 unsigned char byte = value & 0x7f; 2704 value >>= 7; 2705 if (value) 2706 byte |= 0x80; 2707 vec_safe_push (*data_area, byte); 2708 } 2709 while (value); 2710} 2711 2712static void 2713push_sleb128 (vec<uchar, va_gc> **data_area, int value) 2714{ 2715 unsigned char byte; 2716 int more; 2717 2718 do 2719 { 2720 byte = value & 0x7f; 2721 value >>= 7; 2722 more = ! ((value == 0 && (byte & 0x40) == 0) 2723 || (value == -1 && (byte & 0x40) != 0)); 2724 if (more) 2725 byte |= 0x80; 2726 vec_safe_push (*data_area, byte); 2727 } 2728 while (more); 2729} 2730 2731 2732#ifndef HAVE_AS_LEB128 2733static int 2734dw2_size_of_call_site_table (int section) 2735{ 2736 int n = vec_safe_length (crtl->eh.call_site_record_v[section]); 2737 int size = n * (4 + 4 + 4); 2738 int i; 2739 2740 for (i = 0; i < n; ++i) 2741 { 2742 struct call_site_record_d *cs = 2743 (*crtl->eh.call_site_record_v[section])[i]; 2744 size += size_of_uleb128 (cs->action); 2745 } 2746 2747 return size; 2748} 2749 2750static int 2751sjlj_size_of_call_site_table (void) 2752{ 2753 int n = vec_safe_length (crtl->eh.call_site_record_v[0]); 2754 int size = 0; 2755 int i; 2756 2757 for (i = 0; i < n; ++i) 2758 { 2759 struct call_site_record_d *cs = 2760 (*crtl->eh.call_site_record_v[0])[i]; 2761 size += size_of_uleb128 (INTVAL (cs->landing_pad)); 2762 size += size_of_uleb128 (cs->action); 2763 } 2764 2765 return size; 2766} 2767#endif 2768 2769static void 2770dw2_output_call_site_table (int cs_format, int section) 2771{ 2772 int n = vec_safe_length (crtl->eh.call_site_record_v[section]); 2773 int i; 2774 const char *begin; 2775 2776 if (section == 0) 2777 begin = current_function_func_begin_label; 2778 else if (first_function_block_is_cold) 2779 begin = crtl->subsections.hot_section_label; 2780 else 2781 begin = crtl->subsections.cold_section_label; 2782 2783 for (i = 0; i < n; ++i) 2784 { 2785 struct call_site_record_d *cs = (*crtl->eh.call_site_record_v[section])[i]; 2786 char reg_start_lab[32]; 2787 char reg_end_lab[32]; 2788 char landing_pad_lab[32]; 2789 2790 ASM_GENERATE_INTERNAL_LABEL (reg_start_lab, "LEHB", call_site_base + i); 2791 ASM_GENERATE_INTERNAL_LABEL (reg_end_lab, "LEHE", call_site_base + i); 2792 2793 if (cs->landing_pad) 2794 ASM_GENERATE_INTERNAL_LABEL (landing_pad_lab, "L", 2795 CODE_LABEL_NUMBER (cs->landing_pad)); 2796 2797 /* ??? Perhaps use insn length scaling if the assembler supports 2798 generic arithmetic. */ 2799 /* ??? Perhaps use attr_length to choose data1 or data2 instead of 2800 data4 if the function is small enough. */ 2801 if (cs_format == DW_EH_PE_uleb128) 2802 { 2803 dw2_asm_output_delta_uleb128 (reg_start_lab, begin, 2804 "region %d start", i); 2805 dw2_asm_output_delta_uleb128 (reg_end_lab, reg_start_lab, 2806 "length"); 2807 if (cs->landing_pad) 2808 dw2_asm_output_delta_uleb128 (landing_pad_lab, begin, 2809 "landing pad"); 2810 else 2811 dw2_asm_output_data_uleb128 (0, "landing pad"); 2812 } 2813 else 2814 { 2815 dw2_asm_output_delta (4, reg_start_lab, begin, 2816 "region %d start", i); 2817 dw2_asm_output_delta (4, reg_end_lab, reg_start_lab, "length"); 2818 if (cs->landing_pad) 2819 dw2_asm_output_delta (4, landing_pad_lab, begin, 2820 "landing pad"); 2821 else 2822 dw2_asm_output_data (4, 0, "landing pad"); 2823 } 2824 dw2_asm_output_data_uleb128 (cs->action, "action"); 2825 } 2826 2827 call_site_base += n; 2828} 2829 2830static void 2831sjlj_output_call_site_table (void) 2832{ 2833 int n = vec_safe_length (crtl->eh.call_site_record_v[0]); 2834 int i; 2835 2836 for (i = 0; i < n; ++i) 2837 { 2838 struct call_site_record_d *cs = (*crtl->eh.call_site_record_v[0])[i]; 2839 2840 dw2_asm_output_data_uleb128 (INTVAL (cs->landing_pad), 2841 "region %d landing pad", i); 2842 dw2_asm_output_data_uleb128 (cs->action, "action"); 2843 } 2844 2845 call_site_base += n; 2846} 2847 2848/* Switch to the section that should be used for exception tables. */ 2849 2850static void 2851switch_to_exception_section (const char * ARG_UNUSED (fnname)) 2852{ 2853 section *s; 2854 2855 if (exception_section) 2856 s = exception_section; 2857 else 2858 { 2859 /* Compute the section and cache it into exception_section, 2860 unless it depends on the function name. */ 2861 if (targetm_common.have_named_sections) 2862 { 2863 int flags; 2864 2865 if (EH_TABLES_CAN_BE_READ_ONLY) 2866 { 2867 int tt_format = 2868 ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1); 2869 flags = ((! flag_pic 2870 || ((tt_format & 0x70) != DW_EH_PE_absptr 2871 && (tt_format & 0x70) != DW_EH_PE_aligned)) 2872 ? 0 : SECTION_WRITE); 2873 } 2874 else 2875 flags = SECTION_WRITE; 2876 2877#ifdef HAVE_LD_EH_GC_SECTIONS 2878 if (flag_function_sections 2879 || (DECL_COMDAT_GROUP (current_function_decl) && HAVE_COMDAT_GROUP)) 2880 { 2881 char *section_name = XNEWVEC (char, strlen (fnname) + 32); 2882 /* The EH table must match the code section, so only mark 2883 it linkonce if we have COMDAT groups to tie them together. */ 2884 if (DECL_COMDAT_GROUP (current_function_decl) && HAVE_COMDAT_GROUP) 2885 flags |= SECTION_LINKONCE; 2886 sprintf (section_name, ".gcc_except_table.%s", fnname); 2887 s = get_section (section_name, flags, current_function_decl); 2888 free (section_name); 2889 } 2890 else 2891#endif 2892 exception_section 2893 = s = get_section (".gcc_except_table", flags, NULL); 2894 } 2895 else 2896 exception_section 2897 = s = flag_pic ? data_section : readonly_data_section; 2898 } 2899 2900 switch_to_section (s); 2901} 2902 2903 2904/* Output a reference from an exception table to the type_info object TYPE. 2905 TT_FORMAT and TT_FORMAT_SIZE describe the DWARF encoding method used for 2906 the value. */ 2907 2908static void 2909output_ttype (tree type, int tt_format, int tt_format_size) 2910{ 2911 rtx value; 2912 bool is_public = true; 2913 2914 if (type == NULL_TREE) 2915 value = const0_rtx; 2916 else 2917 { 2918 /* FIXME lto. pass_ipa_free_lang_data changes all types to 2919 runtime types so TYPE should already be a runtime type 2920 reference. When pass_ipa_free_lang data is made a default 2921 pass, we can then remove the call to lookup_type_for_runtime 2922 below. */ 2923 if (TYPE_P (type)) 2924 type = lookup_type_for_runtime (type); 2925 2926 value = expand_expr (type, NULL_RTX, VOIDmode, EXPAND_INITIALIZER); 2927 2928 /* Let cgraph know that the rtti decl is used. Not all of the 2929 paths below go through assemble_integer, which would take 2930 care of this for us. */ 2931 STRIP_NOPS (type); 2932 if (TREE_CODE (type) == ADDR_EXPR) 2933 { 2934 type = TREE_OPERAND (type, 0); 2935 if (TREE_CODE (type) == VAR_DECL) 2936 is_public = TREE_PUBLIC (type); 2937 } 2938 else 2939 gcc_assert (TREE_CODE (type) == INTEGER_CST); 2940 } 2941 2942 /* Allow the target to override the type table entry format. */ 2943 if (targetm.asm_out.ttype (value)) 2944 return; 2945 2946 if (tt_format == DW_EH_PE_absptr || tt_format == DW_EH_PE_aligned) 2947 assemble_integer (value, tt_format_size, 2948 tt_format_size * BITS_PER_UNIT, 1); 2949 else 2950 dw2_asm_output_encoded_addr_rtx (tt_format, value, is_public, NULL); 2951} 2952 2953static void 2954output_one_function_exception_table (int section) 2955{ 2956 int tt_format, cs_format, lp_format, i; 2957#ifdef HAVE_AS_LEB128 2958 char ttype_label[32]; 2959 char cs_after_size_label[32]; 2960 char cs_end_label[32]; 2961#else 2962 int call_site_len; 2963#endif 2964 int have_tt_data; 2965 int tt_format_size = 0; 2966 2967 have_tt_data = (vec_safe_length (cfun->eh->ttype_data) 2968 || (targetm.arm_eabi_unwinder 2969 ? vec_safe_length (cfun->eh->ehspec_data.arm_eabi) 2970 : vec_safe_length (cfun->eh->ehspec_data.other))); 2971 2972 /* Indicate the format of the @TType entries. */ 2973 if (! have_tt_data) 2974 tt_format = DW_EH_PE_omit; 2975 else 2976 { 2977 tt_format = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1); 2978#ifdef HAVE_AS_LEB128 2979 ASM_GENERATE_INTERNAL_LABEL (ttype_label, 2980 section ? "LLSDATTC" : "LLSDATT", 2981 current_function_funcdef_no); 2982#endif 2983 tt_format_size = size_of_encoded_value (tt_format); 2984 2985 assemble_align (tt_format_size * BITS_PER_UNIT); 2986 } 2987 2988 targetm.asm_out.internal_label (asm_out_file, section ? "LLSDAC" : "LLSDA", 2989 current_function_funcdef_no); 2990 2991 /* The LSDA header. */ 2992 2993 /* Indicate the format of the landing pad start pointer. An omitted 2994 field implies @LPStart == @Start. */ 2995 /* Currently we always put @LPStart == @Start. This field would 2996 be most useful in moving the landing pads completely out of 2997 line to another section, but it could also be used to minimize 2998 the size of uleb128 landing pad offsets. */ 2999 lp_format = DW_EH_PE_omit; 3000 dw2_asm_output_data (1, lp_format, "@LPStart format (%s)", 3001 eh_data_format_name (lp_format)); 3002 3003 /* @LPStart pointer would go here. */ 3004 3005 dw2_asm_output_data (1, tt_format, "@TType format (%s)", 3006 eh_data_format_name (tt_format)); 3007 3008#ifndef HAVE_AS_LEB128 3009 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) 3010 call_site_len = sjlj_size_of_call_site_table (); 3011 else 3012 call_site_len = dw2_size_of_call_site_table (section); 3013#endif 3014 3015 /* A pc-relative 4-byte displacement to the @TType data. */ 3016 if (have_tt_data) 3017 { 3018#ifdef HAVE_AS_LEB128 3019 char ttype_after_disp_label[32]; 3020 ASM_GENERATE_INTERNAL_LABEL (ttype_after_disp_label, 3021 section ? "LLSDATTDC" : "LLSDATTD", 3022 current_function_funcdef_no); 3023 dw2_asm_output_delta_uleb128 (ttype_label, ttype_after_disp_label, 3024 "@TType base offset"); 3025 ASM_OUTPUT_LABEL (asm_out_file, ttype_after_disp_label); 3026#else 3027 /* Ug. Alignment queers things. */ 3028 unsigned int before_disp, after_disp, last_disp, disp; 3029 3030 before_disp = 1 + 1; 3031 after_disp = (1 + size_of_uleb128 (call_site_len) 3032 + call_site_len 3033 + vec_safe_length (crtl->eh.action_record_data) 3034 + (vec_safe_length (cfun->eh->ttype_data) 3035 * tt_format_size)); 3036 3037 disp = after_disp; 3038 do 3039 { 3040 unsigned int disp_size, pad; 3041 3042 last_disp = disp; 3043 disp_size = size_of_uleb128 (disp); 3044 pad = before_disp + disp_size + after_disp; 3045 if (pad % tt_format_size) 3046 pad = tt_format_size - (pad % tt_format_size); 3047 else 3048 pad = 0; 3049 disp = after_disp + pad; 3050 } 3051 while (disp != last_disp); 3052 3053 dw2_asm_output_data_uleb128 (disp, "@TType base offset"); 3054#endif 3055 } 3056 3057 /* Indicate the format of the call-site offsets. */ 3058#ifdef HAVE_AS_LEB128 3059 cs_format = DW_EH_PE_uleb128; 3060#else 3061 cs_format = DW_EH_PE_udata4; 3062#endif 3063 dw2_asm_output_data (1, cs_format, "call-site format (%s)", 3064 eh_data_format_name (cs_format)); 3065 3066#ifdef HAVE_AS_LEB128 3067 ASM_GENERATE_INTERNAL_LABEL (cs_after_size_label, 3068 section ? "LLSDACSBC" : "LLSDACSB", 3069 current_function_funcdef_no); 3070 ASM_GENERATE_INTERNAL_LABEL (cs_end_label, 3071 section ? "LLSDACSEC" : "LLSDACSE", 3072 current_function_funcdef_no); 3073 dw2_asm_output_delta_uleb128 (cs_end_label, cs_after_size_label, 3074 "Call-site table length"); 3075 ASM_OUTPUT_LABEL (asm_out_file, cs_after_size_label); 3076 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) 3077 sjlj_output_call_site_table (); 3078 else 3079 dw2_output_call_site_table (cs_format, section); 3080 ASM_OUTPUT_LABEL (asm_out_file, cs_end_label); 3081#else 3082 dw2_asm_output_data_uleb128 (call_site_len, "Call-site table length"); 3083 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) 3084 sjlj_output_call_site_table (); 3085 else 3086 dw2_output_call_site_table (cs_format, section); 3087#endif 3088 3089 /* ??? Decode and interpret the data for flag_debug_asm. */ 3090 { 3091 uchar uc; 3092 FOR_EACH_VEC_ELT (*crtl->eh.action_record_data, i, uc) 3093 dw2_asm_output_data (1, uc, i ? NULL : "Action record table"); 3094 } 3095 3096 if (have_tt_data) 3097 assemble_align (tt_format_size * BITS_PER_UNIT); 3098 3099 i = vec_safe_length (cfun->eh->ttype_data); 3100 while (i-- > 0) 3101 { 3102 tree type = (*cfun->eh->ttype_data)[i]; 3103 output_ttype (type, tt_format, tt_format_size); 3104 } 3105 3106#ifdef HAVE_AS_LEB128 3107 if (have_tt_data) 3108 ASM_OUTPUT_LABEL (asm_out_file, ttype_label); 3109#endif 3110 3111 /* ??? Decode and interpret the data for flag_debug_asm. */ 3112 if (targetm.arm_eabi_unwinder) 3113 { 3114 tree type; 3115 for (i = 0; 3116 vec_safe_iterate (cfun->eh->ehspec_data.arm_eabi, i, &type); ++i) 3117 output_ttype (type, tt_format, tt_format_size); 3118 } 3119 else 3120 { 3121 uchar uc; 3122 for (i = 0; 3123 vec_safe_iterate (cfun->eh->ehspec_data.other, i, &uc); ++i) 3124 dw2_asm_output_data (1, uc, 3125 i ? NULL : "Exception specification table"); 3126 } 3127} 3128 3129void 3130output_function_exception_table (const char *fnname) 3131{ 3132 rtx personality = get_personality_function (current_function_decl); 3133 3134 /* Not all functions need anything. */ 3135 if (! crtl->uses_eh_lsda) 3136 return; 3137 3138 if (personality) 3139 { 3140 assemble_external_libcall (personality); 3141 3142 if (targetm.asm_out.emit_except_personality) 3143 targetm.asm_out.emit_except_personality (personality); 3144 } 3145 3146 switch_to_exception_section (fnname); 3147 3148 /* If the target wants a label to begin the table, emit it here. */ 3149 targetm.asm_out.emit_except_table_label (asm_out_file); 3150 3151 output_one_function_exception_table (0); 3152 if (crtl->eh.call_site_record_v[1]) 3153 output_one_function_exception_table (1); 3154 3155 switch_to_section (current_function_section ()); 3156} 3157 3158void 3159set_eh_throw_stmt_table (function *fun, hash_map<gimple, int> *table) 3160{ 3161 fun->eh->throw_stmt_table = table; 3162} 3163 3164hash_map<gimple, int> * 3165get_eh_throw_stmt_table (struct function *fun) 3166{ 3167 return fun->eh->throw_stmt_table; 3168} 3169 3170/* Determine if the function needs an EH personality function. */ 3171 3172enum eh_personality_kind 3173function_needs_eh_personality (struct function *fn) 3174{ 3175 enum eh_personality_kind kind = eh_personality_none; 3176 eh_region i; 3177 3178 FOR_ALL_EH_REGION_FN (i, fn) 3179 { 3180 switch (i->type) 3181 { 3182 case ERT_CLEANUP: 3183 /* Can do with any personality including the generic C one. */ 3184 kind = eh_personality_any; 3185 break; 3186 3187 case ERT_TRY: 3188 case ERT_ALLOWED_EXCEPTIONS: 3189 /* Always needs a EH personality function. The generic C 3190 personality doesn't handle these even for empty type lists. */ 3191 return eh_personality_lang; 3192 3193 case ERT_MUST_NOT_THROW: 3194 /* Always needs a EH personality function. The language may specify 3195 what abort routine that must be used, e.g. std::terminate. */ 3196 return eh_personality_lang; 3197 } 3198 } 3199 3200 return kind; 3201} 3202 3203/* Dump EH information to OUT. */ 3204 3205void 3206dump_eh_tree (FILE * out, struct function *fun) 3207{ 3208 eh_region i; 3209 int depth = 0; 3210 static const char *const type_name[] = { 3211 "cleanup", "try", "allowed_exceptions", "must_not_throw" 3212 }; 3213 3214 i = fun->eh->region_tree; 3215 if (!i) 3216 return; 3217 3218 fprintf (out, "Eh tree:\n"); 3219 while (1) 3220 { 3221 fprintf (out, " %*s %i %s", depth * 2, "", 3222 i->index, type_name[(int) i->type]); 3223 3224 if (i->landing_pads) 3225 { 3226 eh_landing_pad lp; 3227 3228 fprintf (out, " land:"); 3229 if (current_ir_type () == IR_GIMPLE) 3230 { 3231 for (lp = i->landing_pads; lp ; lp = lp->next_lp) 3232 { 3233 fprintf (out, "{%i,", lp->index); 3234 print_generic_expr (out, lp->post_landing_pad, 0); 3235 fputc ('}', out); 3236 if (lp->next_lp) 3237 fputc (',', out); 3238 } 3239 } 3240 else 3241 { 3242 for (lp = i->landing_pads; lp ; lp = lp->next_lp) 3243 { 3244 fprintf (out, "{%i,", lp->index); 3245 if (lp->landing_pad) 3246 fprintf (out, "%i%s,", INSN_UID (lp->landing_pad), 3247 NOTE_P (lp->landing_pad) ? "(del)" : ""); 3248 else 3249 fprintf (out, "(nil),"); 3250 if (lp->post_landing_pad) 3251 { 3252 rtx lab = label_rtx (lp->post_landing_pad); 3253 fprintf (out, "%i%s}", INSN_UID (lab), 3254 NOTE_P (lab) ? "(del)" : ""); 3255 } 3256 else 3257 fprintf (out, "(nil)}"); 3258 if (lp->next_lp) 3259 fputc (',', out); 3260 } 3261 } 3262 } 3263 3264 switch (i->type) 3265 { 3266 case ERT_CLEANUP: 3267 case ERT_MUST_NOT_THROW: 3268 break; 3269 3270 case ERT_TRY: 3271 { 3272 eh_catch c; 3273 fprintf (out, " catch:"); 3274 for (c = i->u.eh_try.first_catch; c; c = c->next_catch) 3275 { 3276 fputc ('{', out); 3277 if (c->label) 3278 { 3279 fprintf (out, "lab:"); 3280 print_generic_expr (out, c->label, 0); 3281 fputc (';', out); 3282 } 3283 print_generic_expr (out, c->type_list, 0); 3284 fputc ('}', out); 3285 if (c->next_catch) 3286 fputc (',', out); 3287 } 3288 } 3289 break; 3290 3291 case ERT_ALLOWED_EXCEPTIONS: 3292 fprintf (out, " filter :%i types:", i->u.allowed.filter); 3293 print_generic_expr (out, i->u.allowed.type_list, 0); 3294 break; 3295 } 3296 fputc ('\n', out); 3297 3298 /* If there are sub-regions, process them. */ 3299 if (i->inner) 3300 i = i->inner, depth++; 3301 /* If there are peers, process them. */ 3302 else if (i->next_peer) 3303 i = i->next_peer; 3304 /* Otherwise, step back up the tree to the next peer. */ 3305 else 3306 { 3307 do 3308 { 3309 i = i->outer; 3310 depth--; 3311 if (i == NULL) 3312 return; 3313 } 3314 while (i->next_peer == NULL); 3315 i = i->next_peer; 3316 } 3317 } 3318} 3319 3320/* Dump the EH tree for FN on stderr. */ 3321 3322DEBUG_FUNCTION void 3323debug_eh_tree (struct function *fn) 3324{ 3325 dump_eh_tree (stderr, fn); 3326} 3327 3328/* Verify invariants on EH datastructures. */ 3329 3330DEBUG_FUNCTION void 3331verify_eh_tree (struct function *fun) 3332{ 3333 eh_region r, outer; 3334 int nvisited_lp, nvisited_r; 3335 int count_lp, count_r, depth, i; 3336 eh_landing_pad lp; 3337 bool err = false; 3338 3339 if (!fun->eh->region_tree) 3340 return; 3341 3342 count_r = 0; 3343 for (i = 1; vec_safe_iterate (fun->eh->region_array, i, &r); ++i) 3344 if (r) 3345 { 3346 if (r->index == i) 3347 count_r++; 3348 else 3349 { 3350 error ("region_array is corrupted for region %i", r->index); 3351 err = true; 3352 } 3353 } 3354 3355 count_lp = 0; 3356 for (i = 1; vec_safe_iterate (fun->eh->lp_array, i, &lp); ++i) 3357 if (lp) 3358 { 3359 if (lp->index == i) 3360 count_lp++; 3361 else 3362 { 3363 error ("lp_array is corrupted for lp %i", lp->index); 3364 err = true; 3365 } 3366 } 3367 3368 depth = nvisited_lp = nvisited_r = 0; 3369 outer = NULL; 3370 r = fun->eh->region_tree; 3371 while (1) 3372 { 3373 if ((*fun->eh->region_array)[r->index] != r) 3374 { 3375 error ("region_array is corrupted for region %i", r->index); 3376 err = true; 3377 } 3378 if (r->outer != outer) 3379 { 3380 error ("outer block of region %i is wrong", r->index); 3381 err = true; 3382 } 3383 if (depth < 0) 3384 { 3385 error ("negative nesting depth of region %i", r->index); 3386 err = true; 3387 } 3388 nvisited_r++; 3389 3390 for (lp = r->landing_pads; lp ; lp = lp->next_lp) 3391 { 3392 if ((*fun->eh->lp_array)[lp->index] != lp) 3393 { 3394 error ("lp_array is corrupted for lp %i", lp->index); 3395 err = true; 3396 } 3397 if (lp->region != r) 3398 { 3399 error ("region of lp %i is wrong", lp->index); 3400 err = true; 3401 } 3402 nvisited_lp++; 3403 } 3404 3405 if (r->inner) 3406 outer = r, r = r->inner, depth++; 3407 else if (r->next_peer) 3408 r = r->next_peer; 3409 else 3410 { 3411 do 3412 { 3413 r = r->outer; 3414 if (r == NULL) 3415 goto region_done; 3416 depth--; 3417 outer = r->outer; 3418 } 3419 while (r->next_peer == NULL); 3420 r = r->next_peer; 3421 } 3422 } 3423 region_done: 3424 if (depth != 0) 3425 { 3426 error ("tree list ends on depth %i", depth); 3427 err = true; 3428 } 3429 if (count_r != nvisited_r) 3430 { 3431 error ("region_array does not match region_tree"); 3432 err = true; 3433 } 3434 if (count_lp != nvisited_lp) 3435 { 3436 error ("lp_array does not match region_tree"); 3437 err = true; 3438 } 3439 3440 if (err) 3441 { 3442 dump_eh_tree (stderr, fun); 3443 internal_error ("verify_eh_tree failed"); 3444 } 3445} 3446 3447#include "gt-except.h" 3448