1 /* Implements exception handling.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001 Free Software Foundation, Inc.
4 Contributed by Mike Stump <mrs@cygnus.com>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 /* An exception is an event that can be signaled from within a
25 function. This event can then be "caught" or "trapped" by the
26 callers of this function. This potentially allows program flow to
27 be transferred to any arbitrary code associated with a function call
28 several levels up the stack.
30 The intended use for this mechanism is for signaling "exceptional
31 events" in an out-of-band fashion, hence its name. The C++ language
32 (and many other OO-styled or functional languages) practically
33 requires such a mechanism, as otherwise it becomes very difficult
34 or even impossible to signal failure conditions in complex
35 situations. The traditional C++ example is when an error occurs in
36 the process of constructing an object; without such a mechanism, it
37 is impossible to signal that the error occurs without adding global
38 state variables and error checks around every object construction.
40 The act of causing this event to occur is referred to as "throwing
41 an exception". (Alternate terms include "raising an exception" or
42 "signaling an exception".) The term "throw" is used because control
43 is returned to the callers of the function that is signaling the
44 exception, and thus there is the concept of "throwing" the
45 exception up the call stack.
47 [ Add updated documentation on how to use this. ] */
58 #include "insn-config.h"
60 #include "integrate.h"
61 #include "hard-reg-set.h"
62 #include "basic-block.h"
64 #include "dwarf2asm.h"
65 #include "dwarf2out.h"
74 /* Provide defaults for stuff that may not be defined when using
76 #ifndef EH_RETURN_STACKADJ_RTX
77 #define EH_RETURN_STACKADJ_RTX 0
79 #ifndef EH_RETURN_HANDLER_RTX
80 #define EH_RETURN_HANDLER_RTX 0
82 #ifndef EH_RETURN_DATA_REGNO
83 #define EH_RETURN_DATA_REGNO(N) INVALID_REGNUM
87 /* Nonzero means enable synchronous exceptions for non-call instructions. */
88 int flag_non_call_exceptions;
90 /* Protect cleanup actions with must-not-throw regions, with a call
91 to the given failure handler. */
92 tree (*lang_protect_cleanup_actions) PARAMS ((void));
94 /* Return true if type A catches type B. */
95 int (*lang_eh_type_covers) PARAMS ((tree a, tree b));
97 /* Map a type to a runtime object to match type. */
98 tree (*lang_eh_runtime_type) PARAMS ((tree));
100 /* A list of labels used for exception handlers. */
101 rtx exception_handler_labels;
103 static int call_site_base;
104 static unsigned int sjlj_funcdef_number;
105 static htab_t type_to_runtime_map;
107 /* Describe the SjLj_Function_Context structure. */
108 static tree sjlj_fc_type_node;
109 static int sjlj_fc_call_site_ofs;
110 static int sjlj_fc_data_ofs;
111 static int sjlj_fc_personality_ofs;
112 static int sjlj_fc_lsda_ofs;
113 static int sjlj_fc_jbuf_ofs;
115 /* Describes one exception region. */
118 /* The immediately surrounding region. */
119 struct eh_region *outer;
121 /* The list of immediately contained regions. */
122 struct eh_region *inner;
123 struct eh_region *next_peer;
125 /* An identifier for this region. */
128 /* Each region does exactly one thing. */
134 ERT_ALLOWED_EXCEPTIONS,
140 /* Holds the action to perform based on the preceding type. */
142 /* A list of catch blocks, a surrounding try block,
143 and the label for continuing after a catch. */
145 struct eh_region *catch;
146 struct eh_region *last_catch;
147 struct eh_region *prev_try;
151 /* The list through the catch handlers, the type object
152 matched, and a pointer to the generated code. */
154 struct eh_region *next_catch;
155 struct eh_region *prev_catch;
160 /* A tree_list of allowed types. */
166 /* The type given by a call to "throw foo();", or discovered
172 /* Retain the cleanup expression even after expansion so that
173 we can match up fixup regions. */
178 /* The real region (by expression and by pointer) that fixup code
182 struct eh_region *real_region;
186 /* Entry point for this region's handler before landing pads are built. */
189 /* Entry point for this region's handler from the runtime eh library. */
192 /* Entry point for this region's handler from an inner region. */
193 rtx post_landing_pad;
195 /* The RESX insn for handing off control to the next outermost handler,
200 /* Used to save exception status for each function. */
203 /* The tree of all regions for this function. */
204 struct eh_region *region_tree;
206 /* The same information as an indexable array. */
207 struct eh_region **region_array;
209 /* The most recently open region. */
210 struct eh_region *cur_region;
212 /* This is the region for which we are processing catch blocks. */
213 struct eh_region *try_region;
215 /* A stack (TREE_LIST) of lists of handlers. The TREE_VALUE of each
216 node is itself a TREE_CHAINed list of handlers for regions that
217 are not yet closed. The TREE_VALUE of each entry contains the
218 handler for the corresponding entry on the ehstack. */
224 int built_landing_pads;
225 int last_region_number;
227 varray_type ttype_data;
228 varray_type ehspec_data;
229 varray_type action_record_data;
231 struct call_site_record
236 int call_site_data_used;
237 int call_site_data_size;
248 static void mark_eh_region PARAMS ((struct eh_region *));
250 static int t2r_eq PARAMS ((const PTR,
252 static hashval_t t2r_hash PARAMS ((const PTR));
253 static int t2r_mark_1 PARAMS ((PTR *, PTR));
254 static void t2r_mark PARAMS ((PTR));
255 static void add_type_for_runtime PARAMS ((tree));
256 static tree lookup_type_for_runtime PARAMS ((tree));
258 static struct eh_region *expand_eh_region_end PARAMS ((void));
260 static rtx get_exception_filter PARAMS ((struct function *));
262 static void collect_eh_region_array PARAMS ((void));
263 static void resolve_fixup_regions PARAMS ((void));
264 static void remove_fixup_regions PARAMS ((void));
265 static void convert_from_eh_region_ranges_1 PARAMS ((rtx *, int *, int));
267 static struct eh_region *duplicate_eh_region_1 PARAMS ((struct eh_region *,
268 struct inline_remap *));
269 static void duplicate_eh_region_2 PARAMS ((struct eh_region *,
270 struct eh_region **));
271 static int ttypes_filter_eq PARAMS ((const PTR,
273 static hashval_t ttypes_filter_hash PARAMS ((const PTR));
274 static int ehspec_filter_eq PARAMS ((const PTR,
276 static hashval_t ehspec_filter_hash PARAMS ((const PTR));
277 static int add_ttypes_entry PARAMS ((htab_t, tree));
278 static int add_ehspec_entry PARAMS ((htab_t, htab_t,
280 static void assign_filter_values PARAMS ((void));
281 static void build_post_landing_pads PARAMS ((void));
282 static void connect_post_landing_pads PARAMS ((void));
283 static void dw2_build_landing_pads PARAMS ((void));
286 static bool sjlj_find_directly_reachable_regions
287 PARAMS ((struct sjlj_lp_info *));
288 static void sjlj_assign_call_site_values
289 PARAMS ((rtx, struct sjlj_lp_info *));
290 static void sjlj_mark_call_sites
291 PARAMS ((struct sjlj_lp_info *));
292 static void sjlj_emit_function_enter PARAMS ((rtx));
293 static void sjlj_emit_function_exit PARAMS ((void));
294 static void sjlj_emit_dispatch_table
295 PARAMS ((rtx, struct sjlj_lp_info *));
296 static void sjlj_build_landing_pads PARAMS ((void));
298 static void remove_exception_handler_label PARAMS ((rtx));
299 static void remove_eh_handler PARAMS ((struct eh_region *));
301 struct reachable_info;
303 /* The return value of reachable_next_level. */
306 /* The given exception is not processed by the given region. */
308 /* The given exception may need processing by the given region. */
310 /* The given exception is completely processed by the given region. */
312 /* The given exception is completely processed by the runtime. */
316 static int check_handled PARAMS ((tree, tree));
317 static void add_reachable_handler
318 PARAMS ((struct reachable_info *, struct eh_region *,
319 struct eh_region *));
320 static enum reachable_code reachable_next_level
321 PARAMS ((struct eh_region *, tree, struct reachable_info *));
323 static int action_record_eq PARAMS ((const PTR,
325 static hashval_t action_record_hash PARAMS ((const PTR));
326 static int add_action_record PARAMS ((htab_t, int, int));
327 static int collect_one_action_chain PARAMS ((htab_t,
328 struct eh_region *));
329 static int add_call_site PARAMS ((rtx, int));
331 static void push_uleb128 PARAMS ((varray_type *,
333 static void push_sleb128 PARAMS ((varray_type *, int));
334 #ifndef HAVE_AS_LEB128
335 static int dw2_size_of_call_site_table PARAMS ((void));
336 static int sjlj_size_of_call_site_table PARAMS ((void));
338 static void dw2_output_call_site_table PARAMS ((void));
339 static void sjlj_output_call_site_table PARAMS ((void));
342 /* Routine to see if exception handling is turned on.
343 DO_WARN is non-zero if we want to inform the user that exception
344 handling is turned off.
346 This is used to ensure that -fexceptions has been specified if the
347 compiler tries to use any exception-specific functions. */
353 if (! flag_exceptions)
355 static int warned = 0;
356 if (! warned && do_warn)
358 error ("exception handling disabled, use -fexceptions to enable");
370 ggc_add_rtx_root (&exception_handler_labels, 1);
372 if (! flag_exceptions)
375 type_to_runtime_map = htab_create (31, t2r_hash, t2r_eq, NULL);
376 ggc_add_root (&type_to_runtime_map, 1, sizeof (htab_t), t2r_mark);
378 /* Create the SjLj_Function_Context structure. This should match
379 the definition in unwind-sjlj.c. */
380 if (USING_SJLJ_EXCEPTIONS)
382 tree f_jbuf, f_per, f_lsda, f_prev, f_cs, f_data, tmp;
384 sjlj_fc_type_node = make_lang_type (RECORD_TYPE);
385 ggc_add_tree_root (&sjlj_fc_type_node, 1);
387 f_prev = build_decl (FIELD_DECL, get_identifier ("__prev"),
388 build_pointer_type (sjlj_fc_type_node));
389 DECL_FIELD_CONTEXT (f_prev) = sjlj_fc_type_node;
391 f_cs = build_decl (FIELD_DECL, get_identifier ("__call_site"),
393 DECL_FIELD_CONTEXT (f_cs) = sjlj_fc_type_node;
395 tmp = build_index_type (build_int_2 (4 - 1, 0));
396 tmp = build_array_type (type_for_mode (word_mode, 1), tmp);
397 f_data = build_decl (FIELD_DECL, get_identifier ("__data"), tmp);
398 DECL_FIELD_CONTEXT (f_data) = sjlj_fc_type_node;
400 f_per = build_decl (FIELD_DECL, get_identifier ("__personality"),
402 DECL_FIELD_CONTEXT (f_per) = sjlj_fc_type_node;
404 f_lsda = build_decl (FIELD_DECL, get_identifier ("__lsda"),
406 DECL_FIELD_CONTEXT (f_lsda) = sjlj_fc_type_node;
408 #ifdef DONT_USE_BUILTIN_SETJMP
410 tmp = build_int_2 (JMP_BUF_SIZE - 1, 0);
412 /* Should be large enough for most systems, if it is not,
413 JMP_BUF_SIZE should be defined with the proper value. It will
414 also tend to be larger than necessary for most systems, a more
415 optimal port will define JMP_BUF_SIZE. */
416 tmp = build_int_2 (FIRST_PSEUDO_REGISTER + 2 - 1, 0);
419 /* This is 2 for builtin_setjmp, plus whatever the target requires
420 via STACK_SAVEAREA_MODE (SAVE_NONLOCAL). */
421 tmp = build_int_2 ((GET_MODE_SIZE (STACK_SAVEAREA_MODE (SAVE_NONLOCAL))
422 / GET_MODE_SIZE (Pmode)) + 2 - 1, 0);
424 tmp = build_index_type (tmp);
425 tmp = build_array_type (ptr_type_node, tmp);
426 f_jbuf = build_decl (FIELD_DECL, get_identifier ("__jbuf"), tmp);
427 #ifdef DONT_USE_BUILTIN_SETJMP
428 /* We don't know what the alignment requirements of the
429 runtime's jmp_buf has. Overestimate. */
430 DECL_ALIGN (f_jbuf) = BIGGEST_ALIGNMENT;
431 DECL_USER_ALIGN (f_jbuf) = 1;
433 DECL_FIELD_CONTEXT (f_jbuf) = sjlj_fc_type_node;
435 TYPE_FIELDS (sjlj_fc_type_node) = f_prev;
436 TREE_CHAIN (f_prev) = f_cs;
437 TREE_CHAIN (f_cs) = f_data;
438 TREE_CHAIN (f_data) = f_per;
439 TREE_CHAIN (f_per) = f_lsda;
440 TREE_CHAIN (f_lsda) = f_jbuf;
442 layout_type (sjlj_fc_type_node);
444 /* Cache the interesting field offsets so that we have
445 easy access from rtl. */
446 sjlj_fc_call_site_ofs
447 = (tree_low_cst (DECL_FIELD_OFFSET (f_cs), 1)
448 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_cs), 1) / BITS_PER_UNIT);
450 = (tree_low_cst (DECL_FIELD_OFFSET (f_data), 1)
451 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_data), 1) / BITS_PER_UNIT);
452 sjlj_fc_personality_ofs
453 = (tree_low_cst (DECL_FIELD_OFFSET (f_per), 1)
454 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_per), 1) / BITS_PER_UNIT);
456 = (tree_low_cst (DECL_FIELD_OFFSET (f_lsda), 1)
457 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_lsda), 1) / BITS_PER_UNIT);
459 = (tree_low_cst (DECL_FIELD_OFFSET (f_jbuf), 1)
460 + tree_low_cst (DECL_FIELD_BIT_OFFSET (f_jbuf), 1) / BITS_PER_UNIT);
465 init_eh_for_function ()
467 cfun->eh = (struct eh_status *) xcalloc (1, sizeof (struct eh_status));
470 /* Mark EH for GC. */
473 mark_eh_region (region)
474 struct eh_region *region;
479 switch (region->type)
482 ggc_mark_tree (region->u.cleanup.exp);
485 ggc_mark_rtx (region->u.try.continue_label);
488 ggc_mark_tree (region->u.catch.type);
490 case ERT_ALLOWED_EXCEPTIONS:
491 ggc_mark_tree (region->u.allowed.type_list);
493 case ERT_MUST_NOT_THROW:
496 ggc_mark_tree (region->u.throw.type);
499 ggc_mark_tree (region->u.fixup.cleanup_exp);
505 ggc_mark_rtx (region->label);
506 ggc_mark_rtx (region->resume);
507 ggc_mark_rtx (region->landing_pad);
508 ggc_mark_rtx (region->post_landing_pad);
513 struct eh_status *eh;
520 /* If we've called collect_eh_region_array, use it. Otherwise walk
521 the tree non-recursively. */
522 if (eh->region_array)
524 for (i = eh->last_region_number; i > 0; --i)
526 struct eh_region *r = eh->region_array[i];
527 if (r && r->region_number == i)
531 else if (eh->region_tree)
533 struct eh_region *r = eh->region_tree;
539 else if (r->next_peer)
547 } while (r->next_peer == NULL);
554 ggc_mark_tree (eh->protect_list);
555 ggc_mark_rtx (eh->filter);
556 ggc_mark_rtx (eh->exc_ptr);
557 ggc_mark_tree_varray (eh->ttype_data);
559 if (eh->call_site_data)
561 for (i = eh->call_site_data_used - 1; i >= 0; --i)
562 ggc_mark_rtx (eh->call_site_data[i].landing_pad);
565 ggc_mark_rtx (eh->ehr_stackadj);
566 ggc_mark_rtx (eh->ehr_handler);
567 ggc_mark_rtx (eh->ehr_label);
569 ggc_mark_rtx (eh->sjlj_fc);
570 ggc_mark_rtx (eh->sjlj_exit_after);
577 struct eh_status *eh = f->eh;
579 if (eh->region_array)
582 for (i = eh->last_region_number; i > 0; --i)
584 struct eh_region *r = eh->region_array[i];
585 /* Mind we don't free a region struct more than once. */
586 if (r && r->region_number == i)
589 free (eh->region_array);
591 else if (eh->region_tree)
593 struct eh_region *next, *r = eh->region_tree;
598 else if (r->next_peer)
612 } while (r->next_peer == NULL);
621 VARRAY_FREE (eh->ttype_data);
622 VARRAY_FREE (eh->ehspec_data);
623 VARRAY_FREE (eh->action_record_data);
624 if (eh->call_site_data)
625 free (eh->call_site_data);
632 /* Start an exception handling region. All instructions emitted
633 after this point are considered to be part of the region until
634 expand_eh_region_end is invoked. */
637 expand_eh_region_start ()
639 struct eh_region *new_region;
640 struct eh_region *cur_region;
646 /* Insert a new blank region as a leaf in the tree. */
647 new_region = (struct eh_region *) xcalloc (1, sizeof (*new_region));
648 cur_region = cfun->eh->cur_region;
649 new_region->outer = cur_region;
652 new_region->next_peer = cur_region->inner;
653 cur_region->inner = new_region;
657 new_region->next_peer = cfun->eh->region_tree;
658 cfun->eh->region_tree = new_region;
660 cfun->eh->cur_region = new_region;
662 /* Create a note marking the start of this region. */
663 new_region->region_number = ++cfun->eh->last_region_number;
664 note = emit_note (NULL, NOTE_INSN_EH_REGION_BEG);
665 NOTE_EH_HANDLER (note) = new_region->region_number;
668 /* Common code to end a region. Returns the region just ended. */
670 static struct eh_region *
671 expand_eh_region_end ()
673 struct eh_region *cur_region = cfun->eh->cur_region;
676 /* Create a nute marking the end of this region. */
677 note = emit_note (NULL, NOTE_INSN_EH_REGION_END);
678 NOTE_EH_HANDLER (note) = cur_region->region_number;
681 cfun->eh->cur_region = cur_region->outer;
686 /* End an exception handling region for a cleanup. HANDLER is an
687 expression to expand for the cleanup. */
690 expand_eh_region_end_cleanup (handler)
693 struct eh_region *region;
694 tree protect_cleanup_actions;
701 region = expand_eh_region_end ();
702 region->type = ERT_CLEANUP;
703 region->label = gen_label_rtx ();
704 region->u.cleanup.exp = handler;
706 around_label = gen_label_rtx ();
707 emit_jump (around_label);
709 emit_label (region->label);
711 /* Give the language a chance to specify an action to be taken if an
712 exception is thrown that would propogate out of the HANDLER. */
713 protect_cleanup_actions
714 = (lang_protect_cleanup_actions
715 ? (*lang_protect_cleanup_actions) ()
718 if (protect_cleanup_actions)
719 expand_eh_region_start ();
721 /* In case this cleanup involves an inline destructor with a try block in
722 it, we need to save the EH return data registers around it. */
723 data_save[0] = gen_reg_rtx (Pmode);
724 emit_move_insn (data_save[0], get_exception_pointer (cfun));
725 data_save[1] = gen_reg_rtx (word_mode);
726 emit_move_insn (data_save[1], get_exception_filter (cfun));
728 expand_expr (handler, const0_rtx, VOIDmode, 0);
730 emit_move_insn (cfun->eh->exc_ptr, data_save[0]);
731 emit_move_insn (cfun->eh->filter, data_save[1]);
733 if (protect_cleanup_actions)
734 expand_eh_region_end_must_not_throw (protect_cleanup_actions);
736 /* We need any stack adjustment complete before the around_label. */
737 do_pending_stack_adjust ();
739 /* We delay the generation of the _Unwind_Resume until we generate
740 landing pads. We emit a marker here so as to get good control
741 flow data in the meantime. */
743 = emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
746 emit_label (around_label);
749 /* End an exception handling region for a try block, and prepares
750 for subsequent calls to expand_start_catch. */
753 expand_start_all_catch ()
755 struct eh_region *region;
760 region = expand_eh_region_end ();
761 region->type = ERT_TRY;
762 region->u.try.prev_try = cfun->eh->try_region;
763 region->u.try.continue_label = gen_label_rtx ();
765 cfun->eh->try_region = region;
767 emit_jump (region->u.try.continue_label);
770 /* Begin a catch clause. TYPE is the type caught, or null if this is
771 a catch-all clause. */
774 expand_start_catch (type)
777 struct eh_region *t, *c, *l;
783 add_type_for_runtime (type);
784 expand_eh_region_start ();
786 t = cfun->eh->try_region;
787 c = cfun->eh->cur_region;
789 c->u.catch.type = type;
790 c->label = gen_label_rtx ();
792 l = t->u.try.last_catch;
793 c->u.catch.prev_catch = l;
795 l->u.catch.next_catch = c;
798 t->u.try.last_catch = c;
800 emit_label (c->label);
803 /* End a catch clause. Control will resume after the try/catch block. */
808 struct eh_region *try_region, *catch_region;
813 catch_region = expand_eh_region_end ();
814 try_region = cfun->eh->try_region;
816 emit_jump (try_region->u.try.continue_label);
819 /* End a sequence of catch handlers for a try block. */
822 expand_end_all_catch ()
824 struct eh_region *try_region;
829 try_region = cfun->eh->try_region;
830 cfun->eh->try_region = try_region->u.try.prev_try;
832 emit_label (try_region->u.try.continue_label);
835 /* End an exception region for an exception type filter. ALLOWED is a
836 TREE_LIST of types to be matched by the runtime. FAILURE is an
837 expression to invoke if a mismatch occurs.
839 ??? We could use these semantics for calls to rethrow, too; if we can
840 see the surrounding catch clause, we know that the exception we're
841 rethrowing satisfies the "filter" of the catch type. */
844 expand_eh_region_end_allowed (allowed, failure)
845 tree allowed, failure;
847 struct eh_region *region;
853 region = expand_eh_region_end ();
854 region->type = ERT_ALLOWED_EXCEPTIONS;
855 region->u.allowed.type_list = allowed;
856 region->label = gen_label_rtx ();
858 for (; allowed ; allowed = TREE_CHAIN (allowed))
859 add_type_for_runtime (TREE_VALUE (allowed));
861 /* We must emit the call to FAILURE here, so that if this function
862 throws a different exception, that it will be processed by the
865 around_label = gen_label_rtx ();
866 emit_jump (around_label);
868 emit_label (region->label);
869 expand_expr (failure, const0_rtx, VOIDmode, EXPAND_NORMAL);
870 /* We must adjust the stack before we reach the AROUND_LABEL because
871 the call to FAILURE does not occur on all paths to the
873 do_pending_stack_adjust ();
875 emit_label (around_label);
878 /* End an exception region for a must-not-throw filter. FAILURE is an
879 expression invoke if an uncaught exception propagates this far.
881 This is conceptually identical to expand_eh_region_end_allowed with
882 an empty allowed list (if you passed "std::terminate" instead of
883 "__cxa_call_unexpected"), but they are represented differently in
887 expand_eh_region_end_must_not_throw (failure)
890 struct eh_region *region;
896 region = expand_eh_region_end ();
897 region->type = ERT_MUST_NOT_THROW;
898 region->label = gen_label_rtx ();
900 /* We must emit the call to FAILURE here, so that if this function
901 throws a different exception, that it will be processed by the
904 around_label = gen_label_rtx ();
905 emit_jump (around_label);
907 emit_label (region->label);
908 expand_expr (failure, const0_rtx, VOIDmode, EXPAND_NORMAL);
910 emit_label (around_label);
913 /* End an exception region for a throw. No handling goes on here,
914 but it's the easiest way for the front-end to indicate what type
918 expand_eh_region_end_throw (type)
921 struct eh_region *region;
926 region = expand_eh_region_end ();
927 region->type = ERT_THROW;
928 region->u.throw.type = type;
931 /* End a fixup region. Within this region the cleanups for the immediately
932 enclosing region are _not_ run. This is used for goto cleanup to avoid
933 destroying an object twice.
935 This would be an extraordinarily simple prospect, were it not for the
936 fact that we don't actually know what the immediately enclosing region
937 is. This surprising fact is because expand_cleanups is currently
938 generating a sequence that it will insert somewhere else. We collect
939 the proper notion of "enclosing" in convert_from_eh_region_ranges. */
942 expand_eh_region_end_fixup (handler)
945 struct eh_region *fixup;
950 fixup = expand_eh_region_end ();
951 fixup->type = ERT_FIXUP;
952 fixup->u.fixup.cleanup_exp = handler;
955 /* Return an rtl expression for a pointer to the exception object
959 get_exception_pointer (fun)
960 struct function *fun;
962 rtx exc_ptr = fun->eh->exc_ptr;
963 if (fun == cfun && ! exc_ptr)
965 exc_ptr = gen_reg_rtx (Pmode);
966 fun->eh->exc_ptr = exc_ptr;
971 /* Return an rtl expression for the exception dispatch filter
975 get_exception_filter (fun)
976 struct function *fun;
978 rtx filter = fun->eh->filter;
979 if (fun == cfun && ! filter)
981 filter = gen_reg_rtx (word_mode);
982 fun->eh->filter = filter;
987 /* Begin a region that will contain entries created with
988 add_partial_entry. */
991 begin_protect_partials ()
993 /* Push room for a new list. */
994 cfun->eh->protect_list
995 = tree_cons (NULL_TREE, NULL_TREE, cfun->eh->protect_list);
998 /* Start a new exception region for a region of code that has a
999 cleanup action and push the HANDLER for the region onto
1000 protect_list. All of the regions created with add_partial_entry
1001 will be ended when end_protect_partials is invoked. */
1004 add_partial_entry (handler)
1007 expand_eh_region_start ();
1009 /* ??? This comment was old before the most recent rewrite. We
1010 really ought to fix the callers at some point. */
1011 /* For backwards compatibility, we allow callers to omit calls to
1012 begin_protect_partials for the outermost region. So, we must
1013 explicitly do so here. */
1014 if (!cfun->eh->protect_list)
1015 begin_protect_partials ();
1017 /* Add this entry to the front of the list. */
1018 TREE_VALUE (cfun->eh->protect_list)
1019 = tree_cons (NULL_TREE, handler, TREE_VALUE (cfun->eh->protect_list));
1022 /* End all the pending exception regions on protect_list. */
1025 end_protect_partials ()
1029 /* ??? This comment was old before the most recent rewrite. We
1030 really ought to fix the callers at some point. */
1031 /* For backwards compatibility, we allow callers to omit the call to
1032 begin_protect_partials for the outermost region. So,
1033 PROTECT_LIST may be NULL. */
1034 if (!cfun->eh->protect_list)
1037 /* Pop the topmost entry. */
1038 t = TREE_VALUE (cfun->eh->protect_list);
1039 cfun->eh->protect_list = TREE_CHAIN (cfun->eh->protect_list);
1041 /* End all the exception regions. */
1042 for (; t; t = TREE_CHAIN (t))
1043 expand_eh_region_end_cleanup (TREE_VALUE (t));
1047 /* This section is for the exception handling specific optimization pass. */
1049 /* Random access the exception region tree. It's just as simple to
1050 collect the regions this way as in expand_eh_region_start, but
1051 without having to realloc memory. */
1054 collect_eh_region_array ()
1056 struct eh_region **array, *i;
1058 i = cfun->eh->region_tree;
1062 array = xcalloc (cfun->eh->last_region_number + 1, sizeof (*array));
1063 cfun->eh->region_array = array;
1067 array[i->region_number] = i;
1069 /* If there are sub-regions, process them. */
1072 /* If there are peers, process them. */
1073 else if (i->next_peer)
1075 /* Otherwise, step back up the tree to the next peer. */
1082 } while (i->next_peer == NULL);
1089 resolve_fixup_regions ()
1091 int i, j, n = cfun->eh->last_region_number;
1093 for (i = 1; i <= n; ++i)
1095 struct eh_region *fixup = cfun->eh->region_array[i];
1096 struct eh_region *cleanup = 0;
1098 if (! fixup || fixup->type != ERT_FIXUP)
1101 for (j = 1; j <= n; ++j)
1103 cleanup = cfun->eh->region_array[j];
1104 if (cleanup->type == ERT_CLEANUP
1105 && cleanup->u.cleanup.exp == fixup->u.fixup.cleanup_exp)
1111 fixup->u.fixup.real_region = cleanup->outer;
1115 /* Now that we've discovered what region actually encloses a fixup,
1116 we can shuffle pointers and remove them from the tree. */
1119 remove_fixup_regions ()
1123 struct eh_region *fixup;
1125 /* Walk the insn chain and adjust the REG_EH_REGION numbers
1126 for instructions referencing fixup regions. This is only
1127 strictly necessary for fixup regions with no parent, but
1128 doesn't hurt to do it for all regions. */
1129 for (insn = get_insns(); insn ; insn = NEXT_INSN (insn))
1131 && (note = find_reg_note (insn, REG_EH_REGION, NULL))
1132 && INTVAL (XEXP (note, 0)) > 0
1133 && (fixup = cfun->eh->region_array[INTVAL (XEXP (note, 0))])
1134 && fixup->type == ERT_FIXUP)
1136 if (fixup->u.fixup.real_region)
1137 XEXP (note, 0) = GEN_INT (fixup->u.fixup.real_region->region_number);
1139 remove_note (insn, note);
1142 /* Remove the fixup regions from the tree. */
1143 for (i = cfun->eh->last_region_number; i > 0; --i)
1145 fixup = cfun->eh->region_array[i];
1149 /* Allow GC to maybe free some memory. */
1150 if (fixup->type == ERT_CLEANUP)
1151 fixup->u.cleanup.exp = NULL_TREE;
1153 if (fixup->type != ERT_FIXUP)
1158 struct eh_region *parent, *p, **pp;
1160 parent = fixup->u.fixup.real_region;
1162 /* Fix up the children's parent pointers; find the end of
1164 for (p = fixup->inner; ; p = p->next_peer)
1171 /* In the tree of cleanups, only outer-inner ordering matters.
1172 So link the children back in anywhere at the correct level. */
1174 pp = &parent->inner;
1176 pp = &cfun->eh->region_tree;
1179 fixup->inner = NULL;
1182 remove_eh_handler (fixup);
1186 /* Turn NOTE_INSN_EH_REGION notes into REG_EH_REGION notes for each
1187 can_throw instruction in the region. */
1190 convert_from_eh_region_ranges_1 (pinsns, orig_sp, cur)
1198 for (insn = *pinsns; insn ; insn = next)
1200 next = NEXT_INSN (insn);
1201 if (GET_CODE (insn) == NOTE)
1203 int kind = NOTE_LINE_NUMBER (insn);
1204 if (kind == NOTE_INSN_EH_REGION_BEG
1205 || kind == NOTE_INSN_EH_REGION_END)
1207 if (kind == NOTE_INSN_EH_REGION_BEG)
1209 struct eh_region *r;
1212 cur = NOTE_EH_HANDLER (insn);
1214 r = cfun->eh->region_array[cur];
1215 if (r->type == ERT_FIXUP)
1217 r = r->u.fixup.real_region;
1218 cur = r ? r->region_number : 0;
1220 else if (r->type == ERT_CATCH)
1223 cur = r ? r->region_number : 0;
1229 /* Removing the first insn of a CALL_PLACEHOLDER sequence
1230 requires extra care to adjust sequence start. */
1231 if (insn == *pinsns)
1237 else if (INSN_P (insn))
1240 && ! find_reg_note (insn, REG_EH_REGION, NULL_RTX)
1241 /* Calls can always potentially throw exceptions, unless
1242 they have a REG_EH_REGION note with a value of 0 or less.
1243 Which should be the only possible kind so far. */
1244 && (GET_CODE (insn) == CALL_INSN
1245 /* If we wanted exceptions for non-call insns, then
1246 any may_trap_p instruction could throw. */
1247 || (flag_non_call_exceptions
1248 && GET_CODE (PATTERN (insn)) != CLOBBER
1249 && GET_CODE (PATTERN (insn)) != USE
1250 && may_trap_p (PATTERN (insn)))))
1252 REG_NOTES (insn) = alloc_EXPR_LIST (REG_EH_REGION, GEN_INT (cur),
1256 if (GET_CODE (insn) == CALL_INSN
1257 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1259 convert_from_eh_region_ranges_1 (&XEXP (PATTERN (insn), 0),
1261 convert_from_eh_region_ranges_1 (&XEXP (PATTERN (insn), 1),
1263 convert_from_eh_region_ranges_1 (&XEXP (PATTERN (insn), 2),
1274 convert_from_eh_region_ranges ()
1279 collect_eh_region_array ();
1280 resolve_fixup_regions ();
1282 stack = xmalloc (sizeof (int) * (cfun->eh->last_region_number + 1));
1283 insns = get_insns ();
1284 convert_from_eh_region_ranges_1 (&insns, stack, 0);
1287 remove_fixup_regions ();
1291 find_exception_handler_labels ()
1293 rtx list = NULL_RTX;
1296 free_EXPR_LIST_list (&exception_handler_labels);
1298 if (cfun->eh->region_tree == NULL)
1301 for (i = cfun->eh->last_region_number; i > 0; --i)
1303 struct eh_region *region = cfun->eh->region_array[i];
1308 if (cfun->eh->built_landing_pads)
1309 lab = region->landing_pad;
1311 lab = region->label;
1314 list = alloc_EXPR_LIST (0, lab, list);
1317 /* For sjlj exceptions, need the return label to remain live until
1318 after landing pad generation. */
1319 if (USING_SJLJ_EXCEPTIONS && ! cfun->eh->built_landing_pads)
1320 list = alloc_EXPR_LIST (0, return_label, list);
1322 exception_handler_labels = list;
1326 static struct eh_region *
1327 duplicate_eh_region_1 (o, map)
1328 struct eh_region *o;
1329 struct inline_remap *map;
1332 = (struct eh_region *) xcalloc (1, sizeof (struct eh_region));
1334 n->region_number = o->region_number + cfun->eh->last_region_number;
1340 case ERT_MUST_NOT_THROW:
1344 if (o->u.try.continue_label)
1345 n->u.try.continue_label
1346 = get_label_from_map (map,
1347 CODE_LABEL_NUMBER (o->u.try.continue_label));
1351 n->u.catch.type = o->u.catch.type;
1354 case ERT_ALLOWED_EXCEPTIONS:
1355 n->u.allowed.type_list = o->u.allowed.type_list;
1359 n->u.throw.type = o->u.throw.type;
1366 n->label = get_label_from_map (map, CODE_LABEL_NUMBER (o->label));
1369 n->resume = map->insn_map[INSN_UID (o->resume)];
1370 if (n->resume == NULL)
1378 duplicate_eh_region_2 (o, n_array)
1379 struct eh_region *o;
1380 struct eh_region **n_array;
1382 struct eh_region *n = n_array[o->region_number];
1387 n->u.try.catch = n_array[o->u.try.catch->region_number];
1388 n->u.try.last_catch = n_array[o->u.try.last_catch->region_number];
1392 if (o->u.catch.next_catch)
1393 n->u.catch.next_catch = n_array[o->u.catch.next_catch->region_number];
1394 if (o->u.catch.prev_catch)
1395 n->u.catch.prev_catch = n_array[o->u.catch.prev_catch->region_number];
1403 n->outer = n_array[o->outer->region_number];
1405 n->inner = n_array[o->inner->region_number];
1407 n->next_peer = n_array[o->next_peer->region_number];
1411 duplicate_eh_regions (ifun, map)
1412 struct function *ifun;
1413 struct inline_remap *map;
1415 int ifun_last_region_number = ifun->eh->last_region_number;
1416 struct eh_region **n_array, *root, *cur;
1419 if (ifun_last_region_number == 0)
1422 n_array = xcalloc (ifun_last_region_number + 1, sizeof (*n_array));
1424 for (i = 1; i <= ifun_last_region_number; ++i)
1426 cur = ifun->eh->region_array[i];
1427 if (!cur || cur->region_number != i)
1429 n_array[i] = duplicate_eh_region_1 (cur, map);
1431 for (i = 1; i <= ifun_last_region_number; ++i)
1433 cur = ifun->eh->region_array[i];
1434 if (!cur || cur->region_number != i)
1436 duplicate_eh_region_2 (cur, n_array);
1439 root = n_array[ifun->eh->region_tree->region_number];
1440 cur = cfun->eh->cur_region;
1443 struct eh_region *p = cur->inner;
1446 while (p->next_peer)
1448 p->next_peer = root;
1453 for (i = 1; i <= ifun_last_region_number; ++i)
1454 if (n_array[i] && n_array[i]->outer == NULL)
1455 n_array[i]->outer = cur;
1459 struct eh_region *p = cfun->eh->region_tree;
1462 while (p->next_peer)
1464 p->next_peer = root;
1467 cfun->eh->region_tree = root;
1472 i = cfun->eh->last_region_number;
1473 cfun->eh->last_region_number = i + ifun_last_region_number;
1479 t2r_eq (pentry, pdata)
1483 tree entry = (tree) pentry;
1484 tree data = (tree) pdata;
1486 return TREE_PURPOSE (entry) == data;
1493 tree entry = (tree) pentry;
1494 return TYPE_HASH (TREE_PURPOSE (entry));
1498 t2r_mark_1 (slot, data)
1500 PTR data ATTRIBUTE_UNUSED;
1502 tree contents = (tree) *slot;
1503 ggc_mark_tree (contents);
1511 htab_traverse (*(htab_t *)addr, t2r_mark_1, NULL);
1515 add_type_for_runtime (type)
1520 slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type,
1521 TYPE_HASH (type), INSERT);
1524 tree runtime = (*lang_eh_runtime_type) (type);
1525 *slot = tree_cons (type, runtime, NULL_TREE);
1530 lookup_type_for_runtime (type)
1535 slot = (tree *) htab_find_slot_with_hash (type_to_runtime_map, type,
1536 TYPE_HASH (type), NO_INSERT);
1538 /* We should have always inserrted the data earlier. */
1539 return TREE_VALUE (*slot);
1543 /* Represent an entry in @TTypes for either catch actions
1544 or exception filter actions. */
1545 struct ttypes_filter
1551 /* Compare ENTRY (a ttypes_filter entry in the hash table) with DATA
1552 (a tree) for a @TTypes type node we are thinking about adding. */
1555 ttypes_filter_eq (pentry, pdata)
1559 const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
1560 tree data = (tree) pdata;
1562 return entry->t == data;
1566 ttypes_filter_hash (pentry)
1569 const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
1570 return TYPE_HASH (entry->t);
1573 /* Compare ENTRY with DATA (both struct ttypes_filter) for a @TTypes
1574 exception specification list we are thinking about adding. */
1575 /* ??? Currently we use the type lists in the order given. Someone
1576 should put these in some canonical order. */
1579 ehspec_filter_eq (pentry, pdata)
1583 const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
1584 const struct ttypes_filter *data = (const struct ttypes_filter *) pdata;
1586 return type_list_equal (entry->t, data->t);
1589 /* Hash function for exception specification lists. */
1592 ehspec_filter_hash (pentry)
1595 const struct ttypes_filter *entry = (const struct ttypes_filter *) pentry;
1599 for (list = entry->t; list ; list = TREE_CHAIN (list))
1600 h = (h << 5) + (h >> 27) + TYPE_HASH (TREE_VALUE (list));
1604 /* Add TYPE to cfun->eh->ttype_data, using TYPES_HASH to speed
1605 up the search. Return the filter value to be used. */
1608 add_ttypes_entry (ttypes_hash, type)
1612 struct ttypes_filter **slot, *n;
1614 slot = (struct ttypes_filter **)
1615 htab_find_slot_with_hash (ttypes_hash, type, TYPE_HASH (type), INSERT);
1617 if ((n = *slot) == NULL)
1619 /* Filter value is a 1 based table index. */
1621 n = (struct ttypes_filter *) xmalloc (sizeof (*n));
1623 n->filter = VARRAY_ACTIVE_SIZE (cfun->eh->ttype_data) + 1;
1626 VARRAY_PUSH_TREE (cfun->eh->ttype_data, type);
1632 /* Add LIST to cfun->eh->ehspec_data, using EHSPEC_HASH and TYPES_HASH
1633 to speed up the search. Return the filter value to be used. */
1636 add_ehspec_entry (ehspec_hash, ttypes_hash, list)
1641 struct ttypes_filter **slot, *n;
1642 struct ttypes_filter dummy;
1645 slot = (struct ttypes_filter **)
1646 htab_find_slot (ehspec_hash, &dummy, INSERT);
1648 if ((n = *slot) == NULL)
1650 /* Filter value is a -1 based byte index into a uleb128 buffer. */
1652 n = (struct ttypes_filter *) xmalloc (sizeof (*n));
1654 n->filter = -(VARRAY_ACTIVE_SIZE (cfun->eh->ehspec_data) + 1);
1657 /* Look up each type in the list and encode its filter
1658 value as a uleb128. Terminate the list with 0. */
1659 for (; list ; list = TREE_CHAIN (list))
1660 push_uleb128 (&cfun->eh->ehspec_data,
1661 add_ttypes_entry (ttypes_hash, TREE_VALUE (list)));
1662 VARRAY_PUSH_UCHAR (cfun->eh->ehspec_data, 0);
1668 /* Generate the action filter values to be used for CATCH and
1669 ALLOWED_EXCEPTIONS regions. When using dwarf2 exception regions,
1670 we use lots of landing pads, and so every type or list can share
1671 the same filter value, which saves table space. */
1674 assign_filter_values ()
1677 htab_t ttypes, ehspec;
1679 VARRAY_TREE_INIT (cfun->eh->ttype_data, 16, "ttype_data");
1680 VARRAY_UCHAR_INIT (cfun->eh->ehspec_data, 64, "ehspec_data");
1682 ttypes = htab_create (31, ttypes_filter_hash, ttypes_filter_eq, free);
1683 ehspec = htab_create (31, ehspec_filter_hash, ehspec_filter_eq, free);
1685 for (i = cfun->eh->last_region_number; i > 0; --i)
1687 struct eh_region *r = cfun->eh->region_array[i];
1689 /* Mind we don't process a region more than once. */
1690 if (!r || r->region_number != i)
1696 r->u.catch.filter = add_ttypes_entry (ttypes, r->u.catch.type);
1699 case ERT_ALLOWED_EXCEPTIONS:
1701 = add_ehspec_entry (ehspec, ttypes, r->u.allowed.type_list);
1709 htab_delete (ttypes);
1710 htab_delete (ehspec);
1714 build_post_landing_pads ()
1718 for (i = cfun->eh->last_region_number; i > 0; --i)
1720 struct eh_region *region = cfun->eh->region_array[i];
1723 /* Mind we don't process a region more than once. */
1724 if (!region || region->region_number != i)
1727 switch (region->type)
1730 /* ??? Collect the set of all non-overlapping catch handlers
1731 all the way up the chain until blocked by a cleanup. */
1732 /* ??? Outer try regions can share landing pads with inner
1733 try regions if the types are completely non-overlapping,
1734 and there are no interveaning cleanups. */
1736 region->post_landing_pad = gen_label_rtx ();
1740 emit_label (region->post_landing_pad);
1742 /* ??? It is mighty inconvenient to call back into the
1743 switch statement generation code in expand_end_case.
1744 Rapid prototyping sez a sequence of ifs. */
1746 struct eh_region *c;
1747 for (c = region->u.try.catch; c ; c = c->u.catch.next_catch)
1749 /* ??? _Unwind_ForcedUnwind wants no match here. */
1750 if (c->u.catch.type == NULL)
1751 emit_jump (c->label);
1753 emit_cmp_and_jump_insns (cfun->eh->filter,
1754 GEN_INT (c->u.catch.filter),
1755 EQ, NULL_RTX, word_mode, 0,
1760 /* We delay the generation of the _Unwind_Resume until we generate
1761 landing pads. We emit a marker here so as to get good control
1762 flow data in the meantime. */
1764 = emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
1770 emit_insns_before (seq, region->u.try.catch->label);
1773 case ERT_ALLOWED_EXCEPTIONS:
1774 region->post_landing_pad = gen_label_rtx ();
1778 emit_label (region->post_landing_pad);
1780 emit_cmp_and_jump_insns (cfun->eh->filter,
1781 GEN_INT (region->u.allowed.filter),
1782 EQ, NULL_RTX, word_mode, 0, region->label);
1784 /* We delay the generation of the _Unwind_Resume until we generate
1785 landing pads. We emit a marker here so as to get good control
1786 flow data in the meantime. */
1788 = emit_jump_insn (gen_rtx_RESX (VOIDmode, region->region_number));
1794 emit_insns_before (seq, region->label);
1798 case ERT_MUST_NOT_THROW:
1799 region->post_landing_pad = region->label;
1804 /* Nothing to do. */
1813 /* Replace RESX patterns with jumps to the next handler if any, or calls to
1814 _Unwind_Resume otherwise. */
1817 connect_post_landing_pads ()
1821 for (i = cfun->eh->last_region_number; i > 0; --i)
1823 struct eh_region *region = cfun->eh->region_array[i];
1824 struct eh_region *outer;
1827 /* Mind we don't process a region more than once. */
1828 if (!region || region->region_number != i)
1831 /* If there is no RESX, or it has been deleted by flow, there's
1832 nothing to fix up. */
1833 if (! region->resume || INSN_DELETED_P (region->resume))
1836 /* Search for another landing pad in this function. */
1837 for (outer = region->outer; outer ; outer = outer->outer)
1838 if (outer->post_landing_pad)
1844 emit_jump (outer->post_landing_pad);
1846 emit_library_call (unwind_resume_libfunc, LCT_THROW,
1847 VOIDmode, 1, cfun->eh->exc_ptr, Pmode);
1851 emit_insns_before (seq, region->resume);
1852 delete_insn (region->resume);
1858 dw2_build_landing_pads ()
1863 for (i = cfun->eh->last_region_number; i > 0; --i)
1865 struct eh_region *region = cfun->eh->region_array[i];
1867 bool clobbers_hard_regs = false;
1869 /* Mind we don't process a region more than once. */
1870 if (!region || region->region_number != i)
1873 if (region->type != ERT_CLEANUP
1874 && region->type != ERT_TRY
1875 && region->type != ERT_ALLOWED_EXCEPTIONS)
1880 region->landing_pad = gen_label_rtx ();
1881 emit_label (region->landing_pad);
1883 #ifdef HAVE_exception_receiver
1884 if (HAVE_exception_receiver)
1885 emit_insn (gen_exception_receiver ());
1888 #ifdef HAVE_nonlocal_goto_receiver
1889 if (HAVE_nonlocal_goto_receiver)
1890 emit_insn (gen_nonlocal_goto_receiver ());
1895 /* If the eh_return data registers are call-saved, then we
1896 won't have considered them clobbered from the call that
1897 threw. Kill them now. */
1900 unsigned r = EH_RETURN_DATA_REGNO (j);
1901 if (r == INVALID_REGNUM)
1903 if (! call_used_regs[r])
1905 emit_insn (gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (Pmode, r)));
1906 clobbers_hard_regs = true;
1910 if (clobbers_hard_regs)
1912 /* @@@ This is a kludge. Not all machine descriptions define a
1913 blockage insn, but we must not allow the code we just generated
1914 to be reordered by scheduling. So emit an ASM_INPUT to act as
1916 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
1919 emit_move_insn (cfun->eh->exc_ptr,
1920 gen_rtx_REG (Pmode, EH_RETURN_DATA_REGNO (0)));
1921 emit_move_insn (cfun->eh->filter,
1922 gen_rtx_REG (word_mode, EH_RETURN_DATA_REGNO (1)));
1927 emit_insns_before (seq, region->post_landing_pad);
1934 int directly_reachable;
1937 int call_site_index;
1941 sjlj_find_directly_reachable_regions (lp_info)
1942 struct sjlj_lp_info *lp_info;
1945 bool found_one = false;
1947 for (insn = get_insns (); insn ; insn = NEXT_INSN (insn))
1949 struct eh_region *region;
1953 if (! INSN_P (insn))
1956 note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
1957 if (!note || INTVAL (XEXP (note, 0)) <= 0)
1960 region = cfun->eh->region_array[INTVAL (XEXP (note, 0))];
1962 type_thrown = NULL_TREE;
1963 if (region->type == ERT_THROW)
1965 type_thrown = region->u.throw.type;
1966 region = region->outer;
1969 /* Find the first containing region that might handle the exception.
1970 That's the landing pad to which we will transfer control. */
1971 for (; region; region = region->outer)
1972 if (reachable_next_level (region, type_thrown, 0) != RNL_NOT_CAUGHT)
1977 lp_info[region->region_number].directly_reachable = 1;
1986 sjlj_assign_call_site_values (dispatch_label, lp_info)
1988 struct sjlj_lp_info *lp_info;
1993 /* First task: build the action table. */
1995 VARRAY_UCHAR_INIT (cfun->eh->action_record_data, 64, "action_record_data");
1996 ar_hash = htab_create (31, action_record_hash, action_record_eq, free);
1998 for (i = cfun->eh->last_region_number; i > 0; --i)
1999 if (lp_info[i].directly_reachable)
2001 struct eh_region *r = cfun->eh->region_array[i];
2002 r->landing_pad = dispatch_label;
2003 lp_info[i].action_index = collect_one_action_chain (ar_hash, r);
2004 if (lp_info[i].action_index != -1)
2005 cfun->uses_eh_lsda = 1;
2008 htab_delete (ar_hash);
2010 /* Next: assign dispatch values. In dwarf2 terms, this would be the
2011 landing pad label for the region. For sjlj though, there is one
2012 common landing pad from which we dispatch to the post-landing pads.
2014 A region receives a dispatch index if it is directly reachable
2015 and requires in-function processing. Regions that share post-landing
2016 pads may share dispatch indices. */
2017 /* ??? Post-landing pad sharing doesn't actually happen at the moment
2018 (see build_post_landing_pads) so we don't bother checking for it. */
2021 for (i = cfun->eh->last_region_number; i > 0; --i)
2022 if (lp_info[i].directly_reachable
2023 && lp_info[i].action_index >= 0)
2024 lp_info[i].dispatch_index = index++;
2026 /* Finally: assign call-site values. If dwarf2 terms, this would be
2027 the region number assigned by convert_to_eh_region_ranges, but
2028 handles no-action and must-not-throw differently. */
2031 for (i = cfun->eh->last_region_number; i > 0; --i)
2032 if (lp_info[i].directly_reachable)
2034 int action = lp_info[i].action_index;
2036 /* Map must-not-throw to otherwise unused call-site index 0. */
2039 /* Map no-action to otherwise unused call-site index -1. */
2040 else if (action == -1)
2042 /* Otherwise, look it up in the table. */
2044 index = add_call_site (GEN_INT (lp_info[i].dispatch_index), action);
2046 lp_info[i].call_site_index = index;
2051 sjlj_mark_call_sites (lp_info)
2052 struct sjlj_lp_info *lp_info;
2054 int last_call_site = -2;
2057 for (insn = get_insns (); insn ; insn = NEXT_INSN (insn))
2059 struct eh_region *region;
2061 rtx note, before, p;
2063 /* Reset value tracking at extended basic block boundaries. */
2064 if (GET_CODE (insn) == CODE_LABEL)
2065 last_call_site = -2;
2067 if (! INSN_P (insn))
2070 note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
2073 /* Calls (and trapping insns) without notes are outside any
2074 exception handling region in this function. Mark them as
2076 if (GET_CODE (insn) == CALL_INSN
2077 || (flag_non_call_exceptions
2078 && may_trap_p (PATTERN (insn))))
2079 this_call_site = -1;
2085 /* Calls that are known to not throw need not be marked. */
2086 if (INTVAL (XEXP (note, 0)) <= 0)
2089 region = cfun->eh->region_array[INTVAL (XEXP (note, 0))];
2090 this_call_site = lp_info[region->region_number].call_site_index;
2093 if (this_call_site == last_call_site)
2096 /* Don't separate a call from it's argument loads. */
2098 if (GET_CODE (insn) == CALL_INSN)
2099 before = find_first_parameter_load (insn, NULL_RTX);
2102 mem = adjust_address (cfun->eh->sjlj_fc, TYPE_MODE (integer_type_node),
2103 sjlj_fc_call_site_ofs);
2104 emit_move_insn (mem, GEN_INT (this_call_site));
2108 emit_insns_before (p, before);
2109 last_call_site = this_call_site;
2113 /* Construct the SjLj_Function_Context. */
2116 sjlj_emit_function_enter (dispatch_label)
2119 rtx fn_begin, fc, mem, seq;
2121 fc = cfun->eh->sjlj_fc;
2125 /* We're storing this libcall's address into memory instead of
2126 calling it directly. Thus, we must call assemble_external_libcall
2127 here, as we can not depend on emit_library_call to do it for us. */
2128 assemble_external_libcall (eh_personality_libfunc);
2129 mem = adjust_address (fc, Pmode, sjlj_fc_personality_ofs);
2130 emit_move_insn (mem, eh_personality_libfunc);
2132 mem = adjust_address (fc, Pmode, sjlj_fc_lsda_ofs);
2133 if (cfun->uses_eh_lsda)
2136 ASM_GENERATE_INTERNAL_LABEL (buf, "LLSDA", sjlj_funcdef_number);
2137 emit_move_insn (mem, gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)));
2140 emit_move_insn (mem, const0_rtx);
2142 #ifdef DONT_USE_BUILTIN_SETJMP
2145 x = emit_library_call_value (setjmp_libfunc, NULL_RTX, LCT_RETURNS_TWICE,
2146 TYPE_MODE (integer_type_node), 1,
2147 plus_constant (XEXP (fc, 0),
2148 sjlj_fc_jbuf_ofs), Pmode);
2150 note = emit_note (NULL, NOTE_INSN_EXPECTED_VALUE);
2151 NOTE_EXPECTED_VALUE (note) = gen_rtx_EQ (VOIDmode, x, const0_rtx);
2153 emit_cmp_and_jump_insns (x, const0_rtx, NE, 0,
2154 TYPE_MODE (integer_type_node), 0, dispatch_label);
2157 expand_builtin_setjmp_setup (plus_constant (XEXP (fc, 0), sjlj_fc_jbuf_ofs),
2161 emit_library_call (unwind_sjlj_register_libfunc, LCT_NORMAL, VOIDmode,
2162 1, XEXP (fc, 0), Pmode);
2167 /* ??? Instead of doing this at the beginning of the function,
2168 do this in a block that is at loop level 0 and dominates all
2169 can_throw_internal instructions. */
2171 for (fn_begin = get_insns (); ; fn_begin = NEXT_INSN (fn_begin))
2172 if (GET_CODE (fn_begin) == NOTE
2173 && NOTE_LINE_NUMBER (fn_begin) == NOTE_INSN_FUNCTION_BEG)
2175 emit_insns_after (seq, fn_begin);
2178 /* Call back from expand_function_end to know where we should put
2179 the call to unwind_sjlj_unregister_libfunc if needed. */
2182 sjlj_emit_function_exit_after (after)
2185 cfun->eh->sjlj_exit_after = after;
2189 sjlj_emit_function_exit ()
2195 emit_library_call (unwind_sjlj_unregister_libfunc, LCT_NORMAL, VOIDmode,
2196 1, XEXP (cfun->eh->sjlj_fc, 0), Pmode);
2201 /* ??? Really this can be done in any block at loop level 0 that
2202 post-dominates all can_throw_internal instructions. This is
2203 the last possible moment. */
2205 emit_insns_after (seq, cfun->eh->sjlj_exit_after);
2209 sjlj_emit_dispatch_table (dispatch_label, lp_info)
2211 struct sjlj_lp_info *lp_info;
2213 int i, first_reachable;
2214 rtx mem, dispatch, seq, fc;
2216 fc = cfun->eh->sjlj_fc;
2220 emit_label (dispatch_label);
2222 #ifndef DONT_USE_BUILTIN_SETJMP
2223 expand_builtin_setjmp_receiver (dispatch_label);
2226 /* Load up dispatch index, exc_ptr and filter values from the
2227 function context. */
2228 mem = adjust_address (fc, TYPE_MODE (integer_type_node),
2229 sjlj_fc_call_site_ofs);
2230 dispatch = copy_to_reg (mem);
2232 mem = adjust_address (fc, word_mode, sjlj_fc_data_ofs);
2233 if (word_mode != Pmode)
2235 #ifdef POINTERS_EXTEND_UNSIGNED
2236 mem = convert_memory_address (Pmode, mem);
2238 mem = convert_to_mode (Pmode, mem, 0);
2241 emit_move_insn (cfun->eh->exc_ptr, mem);
2243 mem = adjust_address (fc, word_mode, sjlj_fc_data_ofs + UNITS_PER_WORD);
2244 emit_move_insn (cfun->eh->filter, mem);
2246 /* Jump to one of the directly reachable regions. */
2247 /* ??? This really ought to be using a switch statement. */
2249 first_reachable = 0;
2250 for (i = cfun->eh->last_region_number; i > 0; --i)
2252 if (! lp_info[i].directly_reachable
2253 || lp_info[i].action_index < 0)
2256 if (! first_reachable)
2258 first_reachable = i;
2262 emit_cmp_and_jump_insns (dispatch, GEN_INT (lp_info[i].dispatch_index),
2263 EQ, NULL_RTX, TYPE_MODE (integer_type_node), 0,
2264 cfun->eh->region_array[i]->post_landing_pad);
2270 emit_insns_before (seq, (cfun->eh->region_array[first_reachable]
2271 ->post_landing_pad));
2275 sjlj_build_landing_pads ()
2277 struct sjlj_lp_info *lp_info;
2279 lp_info = (struct sjlj_lp_info *) xcalloc (cfun->eh->last_region_number + 1,
2280 sizeof (struct sjlj_lp_info));
2282 if (sjlj_find_directly_reachable_regions (lp_info))
2284 rtx dispatch_label = gen_label_rtx ();
2287 = assign_stack_local (TYPE_MODE (sjlj_fc_type_node),
2288 int_size_in_bytes (sjlj_fc_type_node),
2289 TYPE_ALIGN (sjlj_fc_type_node));
2291 sjlj_assign_call_site_values (dispatch_label, lp_info);
2292 sjlj_mark_call_sites (lp_info);
2294 sjlj_emit_function_enter (dispatch_label);
2295 sjlj_emit_dispatch_table (dispatch_label, lp_info);
2296 sjlj_emit_function_exit ();
2303 finish_eh_generation ()
2305 /* Nothing to do if no regions created. */
2306 if (cfun->eh->region_tree == NULL)
2309 /* The object here is to provide find_basic_blocks with detailed
2310 information (via reachable_handlers) on how exception control
2311 flows within the function. In this first pass, we can include
2312 type information garnered from ERT_THROW and ERT_ALLOWED_EXCEPTIONS
2313 regions, and hope that it will be useful in deleting unreachable
2314 handlers. Subsequently, we will generate landing pads which will
2315 connect many of the handlers, and then type information will not
2316 be effective. Still, this is a win over previous implementations. */
2318 rebuild_jump_labels (get_insns ());
2319 find_basic_blocks (get_insns (), max_reg_num (), 0);
2320 cleanup_cfg (CLEANUP_PRE_LOOP);
2322 /* These registers are used by the landing pads. Make sure they
2323 have been generated. */
2324 get_exception_pointer (cfun);
2325 get_exception_filter (cfun);
2327 /* Construct the landing pads. */
2329 assign_filter_values ();
2330 build_post_landing_pads ();
2331 connect_post_landing_pads ();
2332 if (USING_SJLJ_EXCEPTIONS)
2333 sjlj_build_landing_pads ();
2335 dw2_build_landing_pads ();
2337 cfun->eh->built_landing_pads = 1;
2339 /* We've totally changed the CFG. Start over. */
2340 find_exception_handler_labels ();
2341 rebuild_jump_labels (get_insns ());
2342 find_basic_blocks (get_insns (), max_reg_num (), 0);
2343 cleanup_cfg (CLEANUP_PRE_LOOP);
2346 /* This section handles removing dead code for flow. */
2348 /* Remove LABEL from the exception_handler_labels list. */
2351 remove_exception_handler_label (label)
2356 for (pl = &exception_handler_labels, l = *pl;
2357 XEXP (l, 0) != label;
2358 pl = &XEXP (l, 1), l = *pl)
2362 free_EXPR_LIST_node (l);
2365 /* Splice REGION from the region tree etc. */
2368 remove_eh_handler (region)
2369 struct eh_region *region;
2371 struct eh_region **pp, *p;
2375 /* For the benefit of efficiently handling REG_EH_REGION notes,
2376 replace this region in the region array with its containing
2377 region. Note that previous region deletions may result in
2378 multiple copies of this region in the array, so we have to
2379 search the whole thing. */
2380 for (i = cfun->eh->last_region_number; i > 0; --i)
2381 if (cfun->eh->region_array[i] == region)
2382 cfun->eh->region_array[i] = region->outer;
2384 if (cfun->eh->built_landing_pads)
2385 lab = region->landing_pad;
2387 lab = region->label;
2389 remove_exception_handler_label (lab);
2392 pp = ®ion->outer->inner;
2394 pp = &cfun->eh->region_tree;
2395 for (p = *pp; p != region; pp = &p->next_peer, p = *pp)
2400 for (p = region->inner; p->next_peer ; p = p->next_peer)
2401 p->outer = region->outer;
2402 p->next_peer = region->next_peer;
2403 p->outer = region->outer;
2404 *pp = region->inner;
2407 *pp = region->next_peer;
2409 if (region->type == ERT_CATCH)
2411 struct eh_region *try, *next, *prev;
2413 for (try = region->next_peer;
2414 try->type == ERT_CATCH;
2415 try = try->next_peer)
2417 if (try->type != ERT_TRY)
2420 next = region->u.catch.next_catch;
2421 prev = region->u.catch.prev_catch;
2424 next->u.catch.prev_catch = prev;
2426 try->u.try.last_catch = prev;
2428 prev->u.catch.next_catch = next;
2431 try->u.try.catch = next;
2433 remove_eh_handler (try);
2440 /* LABEL heads a basic block that is about to be deleted. If this
2441 label corresponds to an exception region, we may be able to
2442 delete the region. */
2445 maybe_remove_eh_handler (label)
2450 /* ??? After generating landing pads, it's not so simple to determine
2451 if the region data is completely unused. One must examine the
2452 landing pad and the post landing pad, and whether an inner try block
2453 is referencing the catch handlers directly. */
2454 if (cfun->eh->built_landing_pads)
2457 for (i = cfun->eh->last_region_number; i > 0; --i)
2459 struct eh_region *region = cfun->eh->region_array[i];
2460 if (region && region->label == label)
2462 /* Flow will want to remove MUST_NOT_THROW regions as unreachable
2463 because there is no path to the fallback call to terminate.
2464 But the region continues to affect call-site data until there
2465 are no more contained calls, which we don't see here. */
2466 if (region->type == ERT_MUST_NOT_THROW)
2468 remove_exception_handler_label (region->label);
2469 region->label = NULL_RTX;
2472 remove_eh_handler (region);
2479 /* This section describes CFG exception edges for flow. */
2481 /* For communicating between calls to reachable_next_level. */
2482 struct reachable_info
2489 /* A subroutine of reachable_next_level. Return true if TYPE, or a
2490 base class of TYPE, is in HANDLED. */
2493 check_handled (handled, type)
2498 /* We can check for exact matches without front-end help. */
2499 if (! lang_eh_type_covers)
2501 for (t = handled; t ; t = TREE_CHAIN (t))
2502 if (TREE_VALUE (t) == type)
2507 for (t = handled; t ; t = TREE_CHAIN (t))
2508 if ((*lang_eh_type_covers) (TREE_VALUE (t), type))
2515 /* A subroutine of reachable_next_level. If we are collecting a list
2516 of handlers, add one. After landing pad generation, reference
2517 it instead of the handlers themselves. Further, the handlers are
2518 all wired together, so by referencing one, we've got them all.
2519 Before landing pad generation we reference each handler individually.
2521 LP_REGION contains the landing pad; REGION is the handler. */
2524 add_reachable_handler (info, lp_region, region)
2525 struct reachable_info *info;
2526 struct eh_region *lp_region;
2527 struct eh_region *region;
2532 if (cfun->eh->built_landing_pads)
2534 if (! info->handlers)
2535 info->handlers = alloc_INSN_LIST (lp_region->landing_pad, NULL_RTX);
2538 info->handlers = alloc_INSN_LIST (region->label, info->handlers);
2541 /* Process one level of exception regions for reachability.
2542 If TYPE_THROWN is non-null, then it is the *exact* type being
2543 propagated. If INFO is non-null, then collect handler labels
2544 and caught/allowed type information between invocations. */
2546 static enum reachable_code
2547 reachable_next_level (region, type_thrown, info)
2548 struct eh_region *region;
2550 struct reachable_info *info;
2552 switch (region->type)
2555 /* Before landing-pad generation, we model control flow
2556 directly to the individual handlers. In this way we can
2557 see that catch handler types may shadow one another. */
2558 add_reachable_handler (info, region, region);
2559 return RNL_MAYBE_CAUGHT;
2563 struct eh_region *c;
2564 enum reachable_code ret = RNL_NOT_CAUGHT;
2566 for (c = region->u.try.catch; c ; c = c->u.catch.next_catch)
2568 /* A catch-all handler ends the search. */
2569 /* ??? _Unwind_ForcedUnwind will want outer cleanups
2570 to be run as well. */
2571 if (c->u.catch.type == NULL)
2573 add_reachable_handler (info, region, c);
2579 /* If we have a type match, end the search. */
2580 if (c->u.catch.type == type_thrown
2581 || (lang_eh_type_covers
2582 && (*lang_eh_type_covers) (c->u.catch.type,
2585 add_reachable_handler (info, region, c);
2589 /* If we have definitive information of a match failure,
2590 the catch won't trigger. */
2591 if (lang_eh_type_covers)
2592 return RNL_NOT_CAUGHT;
2596 ret = RNL_MAYBE_CAUGHT;
2598 /* A type must not have been previously caught. */
2599 else if (! check_handled (info->types_caught, c->u.catch.type))
2601 add_reachable_handler (info, region, c);
2602 info->types_caught = tree_cons (NULL, c->u.catch.type,
2603 info->types_caught);
2605 /* ??? If the catch type is a base class of every allowed
2606 type, then we know we can stop the search. */
2607 ret = RNL_MAYBE_CAUGHT;
2614 case ERT_ALLOWED_EXCEPTIONS:
2615 /* An empty list of types definitely ends the search. */
2616 if (region->u.allowed.type_list == NULL_TREE)
2618 add_reachable_handler (info, region, region);
2622 /* Collect a list of lists of allowed types for use in detecting
2623 when a catch may be transformed into a catch-all. */
2625 info->types_allowed = tree_cons (NULL_TREE,
2626 region->u.allowed.type_list,
2627 info->types_allowed);
2629 /* If we have definitive information about the type hierarchy,
2630 then we can tell if the thrown type will pass through the
2632 if (type_thrown && lang_eh_type_covers)
2634 if (check_handled (region->u.allowed.type_list, type_thrown))
2635 return RNL_NOT_CAUGHT;
2638 add_reachable_handler (info, region, region);
2643 add_reachable_handler (info, region, region);
2644 return RNL_MAYBE_CAUGHT;
2647 /* Catch regions are handled by their controling try region. */
2648 return RNL_NOT_CAUGHT;
2650 case ERT_MUST_NOT_THROW:
2651 /* Here we end our search, since no exceptions may propagate.
2652 If we've touched down at some landing pad previous, then the
2653 explicit function call we generated may be used. Otherwise
2654 the call is made by the runtime. */
2655 if (info && info->handlers)
2657 add_reachable_handler (info, region, region);
2665 /* Shouldn't see these here. */
2672 /* Retrieve a list of labels of exception handlers which can be
2673 reached by a given insn. */
2676 reachable_handlers (insn)
2679 struct reachable_info info;
2680 struct eh_region *region;
2684 if (GET_CODE (insn) == JUMP_INSN
2685 && GET_CODE (PATTERN (insn)) == RESX)
2686 region_number = XINT (PATTERN (insn), 0);
2689 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
2690 if (!note || INTVAL (XEXP (note, 0)) <= 0)
2692 region_number = INTVAL (XEXP (note, 0));
2695 memset (&info, 0, sizeof (info));
2697 region = cfun->eh->region_array[region_number];
2699 type_thrown = NULL_TREE;
2700 if (GET_CODE (insn) == JUMP_INSN
2701 && GET_CODE (PATTERN (insn)) == RESX)
2703 /* A RESX leaves a region instead of entering it. Thus the
2704 region itself may have been deleted out from under us. */
2707 region = region->outer;
2709 else if (region->type == ERT_THROW)
2711 type_thrown = region->u.throw.type;
2712 region = region->outer;
2715 for (; region; region = region->outer)
2716 if (reachable_next_level (region, type_thrown, &info) >= RNL_CAUGHT)
2719 return info.handlers;
2722 /* Determine if the given INSN can throw an exception that is caught
2723 within the function. */
2726 can_throw_internal (insn)
2729 struct eh_region *region;
2733 if (! INSN_P (insn))
2736 if (GET_CODE (insn) == INSN
2737 && GET_CODE (PATTERN (insn)) == SEQUENCE)
2738 insn = XVECEXP (PATTERN (insn), 0, 0);
2740 if (GET_CODE (insn) == CALL_INSN
2741 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
2744 for (i = 0; i < 3; ++i)
2746 rtx sub = XEXP (PATTERN (insn), i);
2747 for (; sub ; sub = NEXT_INSN (sub))
2748 if (can_throw_internal (sub))
2754 /* Every insn that might throw has an EH_REGION note. */
2755 note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
2756 if (!note || INTVAL (XEXP (note, 0)) <= 0)
2759 region = cfun->eh->region_array[INTVAL (XEXP (note, 0))];
2761 type_thrown = NULL_TREE;
2762 if (region->type == ERT_THROW)
2764 type_thrown = region->u.throw.type;
2765 region = region->outer;
2768 /* If this exception is ignored by each and every containing region,
2769 then control passes straight out. The runtime may handle some
2770 regions, which also do not require processing internally. */
2771 for (; region; region = region->outer)
2773 enum reachable_code how = reachable_next_level (region, type_thrown, 0);
2774 if (how == RNL_BLOCKED)
2776 if (how != RNL_NOT_CAUGHT)
2783 /* Determine if the given INSN can throw an exception that is
2784 visible outside the function. */
2787 can_throw_external (insn)
2790 struct eh_region *region;
2794 if (! INSN_P (insn))
2797 if (GET_CODE (insn) == INSN
2798 && GET_CODE (PATTERN (insn)) == SEQUENCE)
2799 insn = XVECEXP (PATTERN (insn), 0, 0);
2801 if (GET_CODE (insn) == CALL_INSN
2802 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
2805 for (i = 0; i < 3; ++i)
2807 rtx sub = XEXP (PATTERN (insn), i);
2808 for (; sub ; sub = NEXT_INSN (sub))
2809 if (can_throw_external (sub))
2815 note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
2818 /* Calls (and trapping insns) without notes are outside any
2819 exception handling region in this function. We have to
2820 assume it might throw. Given that the front end and middle
2821 ends mark known NOTHROW functions, this isn't so wildly
2823 return (GET_CODE (insn) == CALL_INSN
2824 || (flag_non_call_exceptions
2825 && may_trap_p (PATTERN (insn))));
2827 if (INTVAL (XEXP (note, 0)) <= 0)
2830 region = cfun->eh->region_array[INTVAL (XEXP (note, 0))];
2832 type_thrown = NULL_TREE;
2833 if (region->type == ERT_THROW)
2835 type_thrown = region->u.throw.type;
2836 region = region->outer;
2839 /* If the exception is caught or blocked by any containing region,
2840 then it is not seen by any calling function. */
2841 for (; region ; region = region->outer)
2842 if (reachable_next_level (region, type_thrown, NULL) >= RNL_CAUGHT)
2848 /* True if nothing in this function can throw outside this function. */
2851 nothrow_function_p ()
2855 if (! flag_exceptions)
2858 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
2859 if (can_throw_external (insn))
2861 for (insn = current_function_epilogue_delay_list; insn;
2862 insn = XEXP (insn, 1))
2863 if (can_throw_external (insn))
2870 /* Various hooks for unwind library. */
2872 /* Do any necessary initialization to access arbitrary stack frames.
2873 On the SPARC, this means flushing the register windows. */
2876 expand_builtin_unwind_init ()
2878 /* Set this so all the registers get saved in our frame; we need to be
2879 able to copy the saved values for any registers from frames we unwind. */
2880 current_function_has_nonlocal_label = 1;
2882 #ifdef SETUP_FRAME_ADDRESSES
2883 SETUP_FRAME_ADDRESSES ();
2888 expand_builtin_eh_return_data_regno (arglist)
2891 tree which = TREE_VALUE (arglist);
2892 unsigned HOST_WIDE_INT iwhich;
2894 if (TREE_CODE (which) != INTEGER_CST)
2896 error ("argument of `__builtin_eh_return_regno' must be constant");
2900 iwhich = tree_low_cst (which, 1);
2901 iwhich = EH_RETURN_DATA_REGNO (iwhich);
2902 if (iwhich == INVALID_REGNUM)
2905 #ifdef DWARF_FRAME_REGNUM
2906 iwhich = DWARF_FRAME_REGNUM (iwhich);
2908 iwhich = DBX_REGISTER_NUMBER (iwhich);
2911 return GEN_INT (iwhich);
2914 /* Given a value extracted from the return address register or stack slot,
2915 return the actual address encoded in that value. */
2918 expand_builtin_extract_return_addr (addr_tree)
2921 rtx addr = expand_expr (addr_tree, NULL_RTX, Pmode, 0);
2923 /* First mask out any unwanted bits. */
2924 #ifdef MASK_RETURN_ADDR
2925 expand_and (addr, MASK_RETURN_ADDR, addr);
2928 /* Then adjust to find the real return address. */
2929 #if defined (RETURN_ADDR_OFFSET)
2930 addr = plus_constant (addr, RETURN_ADDR_OFFSET);
2936 /* Given an actual address in addr_tree, do any necessary encoding
2937 and return the value to be stored in the return address register or
2938 stack slot so the epilogue will return to that address. */
2941 expand_builtin_frob_return_addr (addr_tree)
2944 rtx addr = expand_expr (addr_tree, NULL_RTX, ptr_mode, 0);
2946 #ifdef POINTERS_EXTEND_UNSIGNED
2947 if (GET_MODE (addr) != Pmode)
2948 addr = convert_memory_address (Pmode, addr);
2951 #ifdef RETURN_ADDR_OFFSET
2952 addr = force_reg (Pmode, addr);
2953 addr = plus_constant (addr, -RETURN_ADDR_OFFSET);
2959 /* Set up the epilogue with the magic bits we'll need to return to the
2960 exception handler. */
2963 expand_builtin_eh_return (stackadj_tree, handler_tree)
2964 tree stackadj_tree, handler_tree;
2966 rtx stackadj, handler;
2968 stackadj = expand_expr (stackadj_tree, cfun->eh->ehr_stackadj, VOIDmode, 0);
2969 handler = expand_expr (handler_tree, cfun->eh->ehr_handler, VOIDmode, 0);
2971 #ifdef POINTERS_EXTEND_UNSIGNED
2972 if (GET_MODE (stackadj) != Pmode)
2973 stackadj = convert_memory_address (Pmode, stackadj);
2975 if (GET_MODE (handler) != Pmode)
2976 handler = convert_memory_address (Pmode, handler);
2979 if (! cfun->eh->ehr_label)
2981 cfun->eh->ehr_stackadj = copy_to_reg (stackadj);
2982 cfun->eh->ehr_handler = copy_to_reg (handler);
2983 cfun->eh->ehr_label = gen_label_rtx ();
2987 if (stackadj != cfun->eh->ehr_stackadj)
2988 emit_move_insn (cfun->eh->ehr_stackadj, stackadj);
2989 if (handler != cfun->eh->ehr_handler)
2990 emit_move_insn (cfun->eh->ehr_handler, handler);
2993 emit_jump (cfun->eh->ehr_label);
2999 rtx sa, ra, around_label;
3001 if (! cfun->eh->ehr_label)
3004 sa = EH_RETURN_STACKADJ_RTX;
3007 error ("__builtin_eh_return not supported on this target");
3011 current_function_calls_eh_return = 1;
3013 around_label = gen_label_rtx ();
3014 emit_move_insn (sa, const0_rtx);
3015 emit_jump (around_label);
3017 emit_label (cfun->eh->ehr_label);
3018 clobber_return_register ();
3020 #ifdef HAVE_eh_return
3022 emit_insn (gen_eh_return (cfun->eh->ehr_stackadj, cfun->eh->ehr_handler));
3026 ra = EH_RETURN_HANDLER_RTX;
3029 error ("__builtin_eh_return not supported on this target");
3030 ra = gen_reg_rtx (Pmode);
3033 emit_move_insn (sa, cfun->eh->ehr_stackadj);
3034 emit_move_insn (ra, cfun->eh->ehr_handler);
3037 emit_label (around_label);
3040 /* In the following functions, we represent entries in the action table
3041 as 1-based indices. Special cases are:
3043 0: null action record, non-null landing pad; implies cleanups
3044 -1: null action record, null landing pad; implies no action
3045 -2: no call-site entry; implies must_not_throw
3046 -3: we have yet to process outer regions
3048 Further, no special cases apply to the "next" field of the record.
3049 For next, 0 means end of list. */
3051 struct action_record
3059 action_record_eq (pentry, pdata)
3063 const struct action_record *entry = (const struct action_record *) pentry;
3064 const struct action_record *data = (const struct action_record *) pdata;
3065 return entry->filter == data->filter && entry->next == data->next;
3069 action_record_hash (pentry)
3072 const struct action_record *entry = (const struct action_record *) pentry;
3073 return entry->next * 1009 + entry->filter;
3077 add_action_record (ar_hash, filter, next)
3081 struct action_record **slot, *new, tmp;
3083 tmp.filter = filter;
3085 slot = (struct action_record **) htab_find_slot (ar_hash, &tmp, INSERT);
3087 if ((new = *slot) == NULL)
3089 new = (struct action_record *) xmalloc (sizeof (*new));
3090 new->offset = VARRAY_ACTIVE_SIZE (cfun->eh->action_record_data) + 1;
3091 new->filter = filter;
3095 /* The filter value goes in untouched. The link to the next
3096 record is a "self-relative" byte offset, or zero to indicate
3097 that there is no next record. So convert the absolute 1 based
3098 indices we've been carrying around into a displacement. */
3100 push_sleb128 (&cfun->eh->action_record_data, filter);
3102 next -= VARRAY_ACTIVE_SIZE (cfun->eh->action_record_data) + 1;
3103 push_sleb128 (&cfun->eh->action_record_data, next);
3110 collect_one_action_chain (ar_hash, region)
3112 struct eh_region *region;
3114 struct eh_region *c;
3117 /* If we've reached the top of the region chain, then we have
3118 no actions, and require no landing pad. */
3122 switch (region->type)
3125 /* A cleanup adds a zero filter to the beginning of the chain, but
3126 there are special cases to look out for. If there are *only*
3127 cleanups along a path, then it compresses to a zero action.
3128 Further, if there are multiple cleanups along a path, we only
3129 need to represent one of them, as that is enough to trigger
3130 entry to the landing pad at runtime. */
3131 next = collect_one_action_chain (ar_hash, region->outer);
3134 for (c = region->outer; c ; c = c->outer)
3135 if (c->type == ERT_CLEANUP)
3137 return add_action_record (ar_hash, 0, next);
3140 /* Process the associated catch regions in reverse order.
3141 If there's a catch-all handler, then we don't need to
3142 search outer regions. Use a magic -3 value to record
3143 that we havn't done the outer search. */
3145 for (c = region->u.try.last_catch; c ; c = c->u.catch.prev_catch)
3147 if (c->u.catch.type == NULL)
3148 next = add_action_record (ar_hash, c->u.catch.filter, 0);
3153 next = collect_one_action_chain (ar_hash, region->outer);
3155 /* If there is no next action, terminate the chain. */
3158 /* If all outer actions are cleanups or must_not_throw,
3159 we'll have no action record for it, since we had wanted
3160 to encode these states in the call-site record directly.
3161 Add a cleanup action to the chain to catch these. */
3163 next = add_action_record (ar_hash, 0, 0);
3165 next = add_action_record (ar_hash, c->u.catch.filter, next);
3170 case ERT_ALLOWED_EXCEPTIONS:
3171 /* An exception specification adds its filter to the
3172 beginning of the chain. */
3173 next = collect_one_action_chain (ar_hash, region->outer);
3174 return add_action_record (ar_hash, region->u.allowed.filter,
3175 next < 0 ? 0 : next);
3177 case ERT_MUST_NOT_THROW:
3178 /* A must-not-throw region with no inner handlers or cleanups
3179 requires no call-site entry. Note that this differs from
3180 the no handler or cleanup case in that we do require an lsda
3181 to be generated. Return a magic -2 value to record this. */
3186 /* CATCH regions are handled in TRY above. THROW regions are
3187 for optimization information only and produce no output. */
3188 return collect_one_action_chain (ar_hash, region->outer);
3196 add_call_site (landing_pad, action)
3200 struct call_site_record *data = cfun->eh->call_site_data;
3201 int used = cfun->eh->call_site_data_used;
3202 int size = cfun->eh->call_site_data_size;
3206 size = (size ? size * 2 : 64);
3207 data = (struct call_site_record *)
3208 xrealloc (data, sizeof (*data) * size);
3209 cfun->eh->call_site_data = data;
3210 cfun->eh->call_site_data_size = size;
3213 data[used].landing_pad = landing_pad;
3214 data[used].action = action;
3216 cfun->eh->call_site_data_used = used + 1;
3218 return used + call_site_base;
3221 /* Turn REG_EH_REGION notes back into NOTE_INSN_EH_REGION notes.
3222 The new note numbers will not refer to region numbers, but
3223 instead to call site entries. */
3226 convert_to_eh_region_ranges ()
3228 rtx insn, iter, note;
3230 int last_action = -3;
3231 rtx last_action_insn = NULL_RTX;
3232 rtx last_landing_pad = NULL_RTX;
3233 rtx first_no_action_insn = NULL_RTX;
3236 if (USING_SJLJ_EXCEPTIONS || cfun->eh->region_tree == NULL)
3239 VARRAY_UCHAR_INIT (cfun->eh->action_record_data, 64, "action_record_data");
3241 ar_hash = htab_create (31, action_record_hash, action_record_eq, free);
3243 for (iter = get_insns (); iter ; iter = NEXT_INSN (iter))
3246 struct eh_region *region;
3248 rtx this_landing_pad;
3251 if (GET_CODE (insn) == INSN
3252 && GET_CODE (PATTERN (insn)) == SEQUENCE)
3253 insn = XVECEXP (PATTERN (insn), 0, 0);
3255 note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
3258 if (! (GET_CODE (insn) == CALL_INSN
3259 || (flag_non_call_exceptions
3260 && may_trap_p (PATTERN (insn)))))
3267 if (INTVAL (XEXP (note, 0)) <= 0)
3269 region = cfun->eh->region_array[INTVAL (XEXP (note, 0))];
3270 this_action = collect_one_action_chain (ar_hash, region);
3273 /* Existence of catch handlers, or must-not-throw regions
3274 implies that an lsda is needed (even if empty). */
3275 if (this_action != -1)
3276 cfun->uses_eh_lsda = 1;
3278 /* Delay creation of region notes for no-action regions
3279 until we're sure that an lsda will be required. */
3280 else if (last_action == -3)
3282 first_no_action_insn = iter;
3286 /* Cleanups and handlers may share action chains but not
3287 landing pads. Collect the landing pad for this region. */
3288 if (this_action >= 0)
3290 struct eh_region *o;
3291 for (o = region; ! o->landing_pad ; o = o->outer)
3293 this_landing_pad = o->landing_pad;
3296 this_landing_pad = NULL_RTX;
3298 /* Differing actions or landing pads implies a change in call-site
3299 info, which implies some EH_REGION note should be emitted. */
3300 if (last_action != this_action
3301 || last_landing_pad != this_landing_pad)
3303 /* If we'd not seen a previous action (-3) or the previous
3304 action was must-not-throw (-2), then we do not need an
3306 if (last_action >= -1)
3308 /* If we delayed the creation of the begin, do it now. */
3309 if (first_no_action_insn)
3311 call_site = add_call_site (NULL_RTX, 0);
3312 note = emit_note_before (NOTE_INSN_EH_REGION_BEG,
3313 first_no_action_insn);
3314 NOTE_EH_HANDLER (note) = call_site;
3315 first_no_action_insn = NULL_RTX;
3318 note = emit_note_after (NOTE_INSN_EH_REGION_END,
3320 NOTE_EH_HANDLER (note) = call_site;
3323 /* If the new action is must-not-throw, then no region notes
3325 if (this_action >= -1)
3327 call_site = add_call_site (this_landing_pad,
3328 this_action < 0 ? 0 : this_action);
3329 note = emit_note_before (NOTE_INSN_EH_REGION_BEG, iter);
3330 NOTE_EH_HANDLER (note) = call_site;
3333 last_action = this_action;
3334 last_landing_pad = this_landing_pad;
3336 last_action_insn = iter;
3339 if (last_action >= -1 && ! first_no_action_insn)
3341 note = emit_note_after (NOTE_INSN_EH_REGION_END, last_action_insn);
3342 NOTE_EH_HANDLER (note) = call_site;
3345 htab_delete (ar_hash);
3350 push_uleb128 (data_area, value)
3351 varray_type *data_area;
3356 unsigned char byte = value & 0x7f;
3360 VARRAY_PUSH_UCHAR (*data_area, byte);
3366 push_sleb128 (data_area, value)
3367 varray_type *data_area;
3375 byte = value & 0x7f;
3377 more = ! ((value == 0 && (byte & 0x40) == 0)
3378 || (value == -1 && (byte & 0x40) != 0));
3381 VARRAY_PUSH_UCHAR (*data_area, byte);
3387 #ifndef HAVE_AS_LEB128
3389 dw2_size_of_call_site_table ()
3391 int n = cfun->eh->call_site_data_used;
3392 int size = n * (4 + 4 + 4);
3395 for (i = 0; i < n; ++i)
3397 struct call_site_record *cs = &cfun->eh->call_site_data[i];
3398 size += size_of_uleb128 (cs->action);
3405 sjlj_size_of_call_site_table ()
3407 int n = cfun->eh->call_site_data_used;
3411 for (i = 0; i < n; ++i)
3413 struct call_site_record *cs = &cfun->eh->call_site_data[i];
3414 size += size_of_uleb128 (INTVAL (cs->landing_pad));
3415 size += size_of_uleb128 (cs->action);
3423 dw2_output_call_site_table ()
3425 const char *const function_start_lab
3426 = IDENTIFIER_POINTER (current_function_func_begin_label);
3427 int n = cfun->eh->call_site_data_used;
3430 for (i = 0; i < n; ++i)
3432 struct call_site_record *cs = &cfun->eh->call_site_data[i];
3433 char reg_start_lab[32];
3434 char reg_end_lab[32];
3435 char landing_pad_lab[32];
3437 ASM_GENERATE_INTERNAL_LABEL (reg_start_lab, "LEHB", call_site_base + i);
3438 ASM_GENERATE_INTERNAL_LABEL (reg_end_lab, "LEHE", call_site_base + i);
3440 if (cs->landing_pad)
3441 ASM_GENERATE_INTERNAL_LABEL (landing_pad_lab, "L",
3442 CODE_LABEL_NUMBER (cs->landing_pad));
3444 /* ??? Perhaps use insn length scaling if the assembler supports
3445 generic arithmetic. */
3446 /* ??? Perhaps use attr_length to choose data1 or data2 instead of
3447 data4 if the function is small enough. */
3448 #ifdef HAVE_AS_LEB128
3449 dw2_asm_output_delta_uleb128 (reg_start_lab, function_start_lab,
3450 "region %d start", i);
3451 dw2_asm_output_delta_uleb128 (reg_end_lab, reg_start_lab,
3453 if (cs->landing_pad)
3454 dw2_asm_output_delta_uleb128 (landing_pad_lab, function_start_lab,
3457 dw2_asm_output_data_uleb128 (0, "landing pad");
3459 dw2_asm_output_delta (4, reg_start_lab, function_start_lab,
3460 "region %d start", i);
3461 dw2_asm_output_delta (4, reg_end_lab, reg_start_lab, "length");
3462 if (cs->landing_pad)
3463 dw2_asm_output_delta (4, landing_pad_lab, function_start_lab,
3466 dw2_asm_output_data (4, 0, "landing pad");
3468 dw2_asm_output_data_uleb128 (cs->action, "action");
3471 call_site_base += n;
3475 sjlj_output_call_site_table ()
3477 int n = cfun->eh->call_site_data_used;
3480 for (i = 0; i < n; ++i)
3482 struct call_site_record *cs = &cfun->eh->call_site_data[i];
3484 dw2_asm_output_data_uleb128 (INTVAL (cs->landing_pad),
3485 "region %d landing pad", i);
3486 dw2_asm_output_data_uleb128 (cs->action, "action");
3489 call_site_base += n;
3493 output_function_exception_table ()
3495 int tt_format, cs_format, lp_format, i, n;
3496 #ifdef HAVE_AS_LEB128
3497 char ttype_label[32];
3498 char cs_after_size_label[32];
3499 char cs_end_label[32];
3505 int tt_format_size = 0;
3507 /* Not all functions need anything. */
3508 if (! cfun->uses_eh_lsda)
3511 funcdef_number = (USING_SJLJ_EXCEPTIONS
3512 ? sjlj_funcdef_number
3513 : current_funcdef_number);
3515 #ifdef IA64_UNWIND_INFO
3516 fputs ("\t.personality\t", asm_out_file);
3517 output_addr_const (asm_out_file, eh_personality_libfunc);
3518 fputs ("\n\t.handlerdata\n", asm_out_file);
3519 /* Note that varasm still thinks we're in the function's code section.
3520 The ".endp" directive that will immediately follow will take us back. */
3522 (*targetm.asm_out.exception_section) ();
3525 have_tt_data = (VARRAY_ACTIVE_SIZE (cfun->eh->ttype_data) > 0
3526 || VARRAY_ACTIVE_SIZE (cfun->eh->ehspec_data) > 0);
3528 /* Indicate the format of the @TType entries. */
3530 tt_format = DW_EH_PE_omit;
3533 tt_format = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0, /*global=*/1);
3534 #ifdef HAVE_AS_LEB128
3535 ASM_GENERATE_INTERNAL_LABEL (ttype_label, "LLSDATT", funcdef_number);
3537 tt_format_size = size_of_encoded_value (tt_format);
3539 assemble_align (tt_format_size * BITS_PER_UNIT);
3542 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LLSDA", funcdef_number);
3544 /* The LSDA header. */
3546 /* Indicate the format of the landing pad start pointer. An omitted
3547 field implies @LPStart == @Start. */
3548 /* Currently we always put @LPStart == @Start. This field would
3549 be most useful in moving the landing pads completely out of
3550 line to another section, but it could also be used to minimize
3551 the size of uleb128 landing pad offsets. */
3552 lp_format = DW_EH_PE_omit;
3553 dw2_asm_output_data (1, lp_format, "@LPStart format (%s)",
3554 eh_data_format_name (lp_format));
3556 /* @LPStart pointer would go here. */
3558 dw2_asm_output_data (1, tt_format, "@TType format (%s)",
3559 eh_data_format_name (tt_format));
3561 #ifndef HAVE_AS_LEB128
3562 if (USING_SJLJ_EXCEPTIONS)
3563 call_site_len = sjlj_size_of_call_site_table ();
3565 call_site_len = dw2_size_of_call_site_table ();
3568 /* A pc-relative 4-byte displacement to the @TType data. */
3571 #ifdef HAVE_AS_LEB128
3572 char ttype_after_disp_label[32];
3573 ASM_GENERATE_INTERNAL_LABEL (ttype_after_disp_label, "LLSDATTD",
3575 dw2_asm_output_delta_uleb128 (ttype_label, ttype_after_disp_label,
3576 "@TType base offset");
3577 ASM_OUTPUT_LABEL (asm_out_file, ttype_after_disp_label);
3579 /* Ug. Alignment queers things. */
3580 unsigned int before_disp, after_disp, last_disp, disp;
3582 before_disp = 1 + 1;
3583 after_disp = (1 + size_of_uleb128 (call_site_len)
3585 + VARRAY_ACTIVE_SIZE (cfun->eh->action_record_data)
3586 + (VARRAY_ACTIVE_SIZE (cfun->eh->ttype_data)
3592 unsigned int disp_size, pad;
3595 disp_size = size_of_uleb128 (disp);
3596 pad = before_disp + disp_size + after_disp;
3597 if (pad % tt_format_size)
3598 pad = tt_format_size - (pad % tt_format_size);
3601 disp = after_disp + pad;
3603 while (disp != last_disp);
3605 dw2_asm_output_data_uleb128 (disp, "@TType base offset");
3609 /* Indicate the format of the call-site offsets. */
3610 #ifdef HAVE_AS_LEB128
3611 cs_format = DW_EH_PE_uleb128;
3613 cs_format = DW_EH_PE_udata4;
3615 dw2_asm_output_data (1, cs_format, "call-site format (%s)",
3616 eh_data_format_name (cs_format));
3618 #ifdef HAVE_AS_LEB128
3619 ASM_GENERATE_INTERNAL_LABEL (cs_after_size_label, "LLSDACSB",
3621 ASM_GENERATE_INTERNAL_LABEL (cs_end_label, "LLSDACSE",
3623 dw2_asm_output_delta_uleb128 (cs_end_label, cs_after_size_label,
3624 "Call-site table length");
3625 ASM_OUTPUT_LABEL (asm_out_file, cs_after_size_label);
3626 if (USING_SJLJ_EXCEPTIONS)
3627 sjlj_output_call_site_table ();
3629 dw2_output_call_site_table ();
3630 ASM_OUTPUT_LABEL (asm_out_file, cs_end_label);
3632 dw2_asm_output_data_uleb128 (call_site_len,"Call-site table length");
3633 if (USING_SJLJ_EXCEPTIONS)
3634 sjlj_output_call_site_table ();
3636 dw2_output_call_site_table ();
3639 /* ??? Decode and interpret the data for flag_debug_asm. */
3640 n = VARRAY_ACTIVE_SIZE (cfun->eh->action_record_data);
3641 for (i = 0; i < n; ++i)
3642 dw2_asm_output_data (1, VARRAY_UCHAR (cfun->eh->action_record_data, i),
3643 (i ? NULL : "Action record table"));
3646 assemble_align (tt_format_size * BITS_PER_UNIT);
3648 i = VARRAY_ACTIVE_SIZE (cfun->eh->ttype_data);
3651 tree type = VARRAY_TREE (cfun->eh->ttype_data, i);
3654 if (type == NULL_TREE)
3655 type = integer_zero_node;
3657 type = lookup_type_for_runtime (type);
3659 value = expand_expr (type, NULL_RTX, VOIDmode, EXPAND_INITIALIZER);
3660 if (tt_format == DW_EH_PE_absptr || tt_format == DW_EH_PE_aligned)
3661 assemble_integer (value, tt_format_size,
3662 tt_format_size * BITS_PER_UNIT, 1);
3664 dw2_asm_output_encoded_addr_rtx (tt_format, value, NULL);
3667 #ifdef HAVE_AS_LEB128
3669 ASM_OUTPUT_LABEL (asm_out_file, ttype_label);
3672 /* ??? Decode and interpret the data for flag_debug_asm. */
3673 n = VARRAY_ACTIVE_SIZE (cfun->eh->ehspec_data);
3674 for (i = 0; i < n; ++i)
3675 dw2_asm_output_data (1, VARRAY_UCHAR (cfun->eh->ehspec_data, i),
3676 (i ? NULL : "Exception specification table"));
3678 function_section (current_function_decl);
3680 if (USING_SJLJ_EXCEPTIONS)
3681 sjlj_funcdef_number += 1;