Daily bump.
[official-gcc.git] / gcc / except.h
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1 /* Exception Handling interface routines.
2 Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2007, 2008, 2009, 2010 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 3, or (at your option) any later
11 version.
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
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* No include guards here, but define an include file marker anyway, so
23 that the compiler can keep track of where this file is included. This
24 is e.g. used to avoid including this file in front-end specific files. */
25 #ifndef GCC_EXCEPT_H
26 # define GCC_EXCEPT_H
27 #endif
29 #include "hashtab.h"
30 #include "vecprim.h"
31 #include "vecir.h"
33 struct function;
34 struct eh_region_d;
35 struct pointer_map_t;
37 /* The type of an exception region. */
38 enum eh_region_type
40 /* CLEANUP regions implement e.g. destructors run when exiting a block.
41 They can be generated from both GIMPLE_TRY_FINALLY and GIMPLE_TRY_CATCH
42 nodes. It is expected by the runtime that cleanup regions will *not*
43 resume normal program flow, but will continue propagation of the
44 exception. */
45 ERT_CLEANUP,
47 /* TRY regions implement catching an exception. The list of types associated
48 with the attached catch handlers is examined in order by the runtime and
49 control is transfered to the appropriate handler. Note that a NULL type
50 list is a catch-all handler, and that it will catch *all* exceptions
51 including those originating from a different language. */
52 ERT_TRY,
54 /* ALLOWED_EXCEPTIONS regions implement exception filtering, e.g. the
55 throw(type-list) specification that can be added to C++ functions.
56 The runtime examines the thrown exception vs the type list, and if
57 the exception does not match, transfers control to the handler. The
58 normal handler for C++ calls __cxa_call_unexpected. */
59 ERT_ALLOWED_EXCEPTIONS,
61 /* MUST_NOT_THROW regions prevent all exceptions from propagating. This
62 region type is used in C++ to surround destructors being run inside a
63 CLEANUP region. This differs from an ALLOWED_EXCEPTIONS region with
64 an empty type list in that the runtime is prepared to terminate the
65 program directly. We only generate code for MUST_NOT_THROW regions
66 along control paths that are already handling an exception within the
67 current function. */
68 ERT_MUST_NOT_THROW
72 /* A landing pad for a given exception region. Any transfer of control
73 from the EH runtime to the function happens at a landing pad. */
75 struct GTY(()) eh_landing_pad_d
77 /* The linked list of all landing pads associated with the region. */
78 struct eh_landing_pad_d *next_lp;
80 /* The region with which this landing pad is associated. */
81 struct eh_region_d *region;
83 /* At the gimple level, the location to which control will be transfered
84 for this landing pad. There can be both EH and normal edges into the
85 block containing the post-landing-pad label. */
86 tree post_landing_pad;
88 /* At the rtl level, the location to which the runtime will transfer
89 control. This differs from the post-landing-pad in that the target's
90 EXCEPTION_RECEIVER pattern will be expanded here, as well as other
91 bookkeeping specific to exceptions. There must not be normal edges
92 into the block containing the landing-pad label. */
93 rtx landing_pad;
95 /* The index of this landing pad within fun->eh->lp_array. */
96 int index;
99 /* A catch handler associated with an ERT_TRY region. */
101 struct GTY(()) eh_catch_d
103 /* The double-linked list of all catch handlers for the region. */
104 struct eh_catch_d *next_catch;
105 struct eh_catch_d *prev_catch;
107 /* A TREE_LIST of runtime type objects that this catch handler
108 will catch, or NULL if all exceptions are caught. */
109 tree type_list;
111 /* A TREE_LIST of INTEGER_CSTs that correspond to the type_list entries,
112 having been mapped by assign_filter_values. These integers are to be
113 compared against the __builtin_eh_filter value. */
114 tree filter_list;
116 /* The code that should be executed if this catch handler matches the
117 thrown exception. This label is only maintained until
118 pass_lower_eh_dispatch, at which point it is cleared. */
119 tree label;
122 /* Describes one exception region. */
124 struct GTY(()) eh_region_d
126 /* The immediately surrounding region. */
127 struct eh_region_d *outer;
129 /* The list of immediately contained regions. */
130 struct eh_region_d *inner;
131 struct eh_region_d *next_peer;
133 /* The index of this region within fun->eh->region_array. */
134 int index;
136 /* Each region does exactly one thing. */
137 enum eh_region_type type;
139 /* Holds the action to perform based on the preceding type. */
140 union eh_region_u {
141 struct eh_region_u_try {
142 /* The double-linked list of all catch handlers for this region. */
143 struct eh_catch_d *first_catch;
144 struct eh_catch_d *last_catch;
145 } GTY ((tag ("ERT_TRY"))) eh_try;
147 struct eh_region_u_allowed {
148 /* A TREE_LIST of runtime type objects allowed to pass. */
149 tree type_list;
150 /* The code that should be executed if the thrown exception does
151 not match the type list. This label is only maintained until
152 pass_lower_eh_dispatch, at which point it is cleared. */
153 tree label;
154 /* The integer that will be passed by the runtime to signal that
155 we should execute the code at LABEL. This integer is assigned
156 by assign_filter_values and is to be compared against the
157 __builtin_eh_filter value. */
158 int filter;
159 } GTY ((tag ("ERT_ALLOWED_EXCEPTIONS"))) allowed;
161 struct eh_region_u_must_not_throw {
162 /* A function decl to be invoked if this region is actually reachable
163 from within the function, rather than implementable from the runtime.
164 The normal way for this to happen is for there to be a CLEANUP region
165 contained within this MUST_NOT_THROW region. Note that if the
166 runtime handles the MUST_NOT_THROW region, we have no control over
167 what termination function is called; it will be decided by the
168 personality function in effect for this CIE. */
169 tree failure_decl;
170 /* The location assigned to the call of FAILURE_DECL, if expanded. */
171 location_t failure_loc;
172 } GTY ((tag ("ERT_MUST_NOT_THROW"))) must_not_throw;
173 } GTY ((desc ("%0.type"))) u;
175 /* The list of landing pads associated with this region. */
176 struct eh_landing_pad_d *landing_pads;
178 /* EXC_PTR and FILTER values copied from the runtime for this region.
179 Each region gets its own psuedos so that if there are nested exceptions
180 we do not overwrite the values of the first exception. */
181 rtx exc_ptr_reg, filter_reg;
183 /* True if this region should use __cxa_end_cleanup instead
184 of _Unwind_Resume. */
185 bool use_cxa_end_cleanup;
188 typedef struct eh_landing_pad_d *eh_landing_pad;
189 typedef struct eh_catch_d *eh_catch;
190 typedef struct eh_region_d *eh_region;
192 DEF_VEC_P(eh_region);
193 DEF_VEC_ALLOC_P(eh_region, gc);
194 DEF_VEC_ALLOC_P(eh_region, heap);
196 DEF_VEC_P(eh_landing_pad);
197 DEF_VEC_ALLOC_P(eh_landing_pad, gc);
200 /* The exception status for each function. */
202 struct GTY(()) eh_status
204 /* The tree of all regions for this function. */
205 eh_region region_tree;
207 /* The same information as an indexable array. */
208 VEC(eh_region,gc) *region_array;
210 /* The landing pads as an indexable array. */
211 VEC(eh_landing_pad,gc) *lp_array;
213 /* At the gimple level, a mapping from gimple statement to landing pad
214 or must-not-throw region. See record_stmt_eh_region. */
215 htab_t GTY((param_is (struct throw_stmt_node))) throw_stmt_table;
217 /* All of the runtime type data used by the function. These objects
218 are emitted to the lang-specific-data-area for the function. */
219 VEC(tree,gc) *ttype_data;
221 /* The table of all action chains. These encode the eh_region tree in
222 a compact form for use by the runtime, and is also emitted to the
223 lang-specific-data-area. Note that the ARM EABI uses a different
224 format for the encoding than all other ports. */
225 union eh_status_u {
226 VEC(tree,gc) * GTY((tag ("1"))) arm_eabi;
227 VEC(uchar,gc) * GTY((tag ("0"))) other;
228 } GTY ((desc ("targetm.arm_eabi_unwinder"))) ehspec_data;
232 /* Invokes CALLBACK for every exception handler label. Only used by old
233 loop hackery; should not be used by new code. */
234 extern void for_each_eh_label (void (*) (rtx));
236 extern void init_eh_for_function (void);
238 extern void remove_eh_landing_pad (eh_landing_pad);
239 extern void remove_eh_handler (eh_region);
241 extern bool current_function_has_exception_handlers (void);
242 extern void output_function_exception_table (const char *);
244 extern rtx expand_builtin_eh_pointer (tree);
245 extern rtx expand_builtin_eh_filter (tree);
246 extern rtx expand_builtin_eh_copy_values (tree);
247 extern void expand_builtin_unwind_init (void);
248 extern rtx expand_builtin_eh_return_data_regno (tree);
249 extern rtx expand_builtin_extract_return_addr (tree);
250 extern void expand_builtin_init_dwarf_reg_sizes (tree);
251 extern rtx expand_builtin_frob_return_addr (tree);
252 extern rtx expand_builtin_dwarf_sp_column (void);
253 extern void expand_builtin_eh_return (tree, tree);
254 extern void expand_eh_return (void);
255 extern rtx expand_builtin_extend_pointer (tree);
257 typedef tree (*duplicate_eh_regions_map) (tree, void *);
258 extern struct pointer_map_t *duplicate_eh_regions
259 (struct function *, eh_region, int, duplicate_eh_regions_map, void *);
261 extern void sjlj_emit_function_exit_after (rtx);
263 extern eh_region gen_eh_region_cleanup (eh_region);
264 extern eh_region gen_eh_region_try (eh_region);
265 extern eh_region gen_eh_region_allowed (eh_region, tree);
266 extern eh_region gen_eh_region_must_not_throw (eh_region);
268 extern eh_catch gen_eh_region_catch (eh_region, tree);
269 extern eh_landing_pad gen_eh_landing_pad (eh_region);
271 extern eh_region get_eh_region_from_number_fn (struct function *, int);
272 extern eh_region get_eh_region_from_number (int);
273 extern eh_landing_pad get_eh_landing_pad_from_number_fn (struct function*,int);
274 extern eh_landing_pad get_eh_landing_pad_from_number (int);
275 extern eh_region get_eh_region_from_lp_number_fn (struct function *, int);
276 extern eh_region get_eh_region_from_lp_number (int);
278 extern eh_region eh_region_outermost (struct function *, eh_region, eh_region);
280 extern void make_reg_eh_region_note (rtx insn, int ecf_flags, int lp_nr);
281 extern void make_reg_eh_region_note_nothrow_nononlocal (rtx);
283 extern void verify_eh_tree (struct function *);
284 extern void dump_eh_tree (FILE *, struct function *);
285 void debug_eh_tree (struct function *);
286 extern void add_type_for_runtime (tree);
287 extern tree lookup_type_for_runtime (tree);
288 extern void assign_filter_values (void);
290 extern eh_region get_eh_region_from_rtx (const_rtx);
291 extern eh_landing_pad get_eh_landing_pad_from_rtx (const_rtx);
293 struct GTY(()) throw_stmt_node {
294 gimple stmt;
295 int lp_nr;
298 extern struct htab *get_eh_throw_stmt_table (struct function *);
299 extern void set_eh_throw_stmt_table (struct function *, struct htab *);
301 enum eh_personality_kind {
302 eh_personality_none,
303 eh_personality_any,
304 eh_personality_lang
307 extern enum eh_personality_kind
308 function_needs_eh_personality (struct function *);
310 /* Pre-order iteration within the eh_region tree. */
312 static inline eh_region
313 ehr_next (eh_region r, eh_region start)
315 if (r->inner)
316 r = r->inner;
317 else if (r->next_peer && r != start)
318 r = r->next_peer;
319 else
323 r = r->outer;
324 if (r == start)
325 return NULL;
327 while (r->next_peer == NULL);
328 r = r->next_peer;
330 return r;
333 #define FOR_ALL_EH_REGION_AT(R, START) \
334 for ((R) = (START); (R) != NULL; (R) = ehr_next (R, START))
336 #define FOR_ALL_EH_REGION_FN(R, FN) \
337 for ((R) = (FN)->eh->region_tree; (R) != NULL; (R) = ehr_next (R, NULL))
339 #define FOR_ALL_EH_REGION(R) FOR_ALL_EH_REGION_FN (R, cfun)