Daily bump.
[official-gcc.git] / gcc / except.h
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1 /* Exception Handling interface routines.
2 Copyright (C) 1996-2014 Free Software Foundation, Inc.
3 Contributed by Mike Stump <mrs@cygnus.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* No include guards here, but define an include file marker anyway, so
22 that the compiler can keep track of where this file is included. This
23 is e.g. used to avoid including this file in front-end specific files. */
24 #ifndef GCC_EXCEPT_H
25 #define GCC_EXCEPT_H
27 #include "hash-map.h"
28 #include "hashtab.h"
30 struct function;
31 struct eh_region_d;
33 /* The type of an exception region. */
34 enum eh_region_type
36 /* CLEANUP regions implement e.g. destructors run when exiting a block.
37 They can be generated from both GIMPLE_TRY_FINALLY and GIMPLE_TRY_CATCH
38 nodes. It is expected by the runtime that cleanup regions will *not*
39 resume normal program flow, but will continue propagation of the
40 exception. */
41 ERT_CLEANUP,
43 /* TRY regions implement catching an exception. The list of types associated
44 with the attached catch handlers is examined in order by the runtime and
45 control is transferred to the appropriate handler. Note that a NULL type
46 list is a catch-all handler, and that it will catch *all* exceptions
47 including those originating from a different language. */
48 ERT_TRY,
50 /* ALLOWED_EXCEPTIONS regions implement exception filtering, e.g. the
51 throw(type-list) specification that can be added to C++ functions.
52 The runtime examines the thrown exception vs the type list, and if
53 the exception does not match, transfers control to the handler. The
54 normal handler for C++ calls __cxa_call_unexpected. */
55 ERT_ALLOWED_EXCEPTIONS,
57 /* MUST_NOT_THROW regions prevent all exceptions from propagating. This
58 region type is used in C++ to surround destructors being run inside a
59 CLEANUP region. This differs from an ALLOWED_EXCEPTIONS region with
60 an empty type list in that the runtime is prepared to terminate the
61 program directly. We only generate code for MUST_NOT_THROW regions
62 along control paths that are already handling an exception within the
63 current function. */
64 ERT_MUST_NOT_THROW
68 /* A landing pad for a given exception region. Any transfer of control
69 from the EH runtime to the function happens at a landing pad. */
71 struct GTY(()) eh_landing_pad_d
73 /* The linked list of all landing pads associated with the region. */
74 struct eh_landing_pad_d *next_lp;
76 /* The region with which this landing pad is associated. */
77 struct eh_region_d *region;
79 /* At the gimple level, the location to which control will be transferred
80 for this landing pad. There can be both EH and normal edges into the
81 block containing the post-landing-pad label. */
82 tree post_landing_pad;
84 /* At the rtl level, the location to which the runtime will transfer
85 control. This differs from the post-landing-pad in that the target's
86 EXCEPTION_RECEIVER pattern will be expanded here, as well as other
87 bookkeeping specific to exceptions. There must not be normal edges
88 into the block containing the landing-pad label. */
89 rtx_code_label *landing_pad;
91 /* The index of this landing pad within fun->eh->lp_array. */
92 int index;
95 /* A catch handler associated with an ERT_TRY region. */
97 struct GTY(()) eh_catch_d
99 /* The double-linked list of all catch handlers for the region. */
100 struct eh_catch_d *next_catch;
101 struct eh_catch_d *prev_catch;
103 /* A TREE_LIST of runtime type objects that this catch handler
104 will catch, or NULL if all exceptions are caught. */
105 tree type_list;
107 /* A TREE_LIST of INTEGER_CSTs that correspond to the type_list entries,
108 having been mapped by assign_filter_values. These integers are to be
109 compared against the __builtin_eh_filter value. */
110 tree filter_list;
112 /* The code that should be executed if this catch handler matches the
113 thrown exception. This label is only maintained until
114 pass_lower_eh_dispatch, at which point it is cleared. */
115 tree label;
118 /* Describes one exception region. */
120 struct GTY(()) eh_region_d
122 /* The immediately surrounding region. */
123 struct eh_region_d *outer;
125 /* The list of immediately contained regions. */
126 struct eh_region_d *inner;
127 struct eh_region_d *next_peer;
129 /* The index of this region within fun->eh->region_array. */
130 int index;
132 /* Each region does exactly one thing. */
133 enum eh_region_type type;
135 /* Holds the action to perform based on the preceding type. */
136 union eh_region_u {
137 struct eh_region_u_try {
138 /* The double-linked list of all catch handlers for this region. */
139 struct eh_catch_d *first_catch;
140 struct eh_catch_d *last_catch;
141 } GTY ((tag ("ERT_TRY"))) eh_try;
143 struct eh_region_u_allowed {
144 /* A TREE_LIST of runtime type objects allowed to pass. */
145 tree type_list;
146 /* The code that should be executed if the thrown exception does
147 not match the type list. This label is only maintained until
148 pass_lower_eh_dispatch, at which point it is cleared. */
149 tree label;
150 /* The integer that will be passed by the runtime to signal that
151 we should execute the code at LABEL. This integer is assigned
152 by assign_filter_values and is to be compared against the
153 __builtin_eh_filter value. */
154 int filter;
155 } GTY ((tag ("ERT_ALLOWED_EXCEPTIONS"))) allowed;
157 struct eh_region_u_must_not_throw {
158 /* A function decl to be invoked if this region is actually reachable
159 from within the function, rather than implementable from the runtime.
160 The normal way for this to happen is for there to be a CLEANUP region
161 contained within this MUST_NOT_THROW region. Note that if the
162 runtime handles the MUST_NOT_THROW region, we have no control over
163 what termination function is called; it will be decided by the
164 personality function in effect for this CIE. */
165 tree failure_decl;
166 /* The location assigned to the call of FAILURE_DECL, if expanded. */
167 location_t failure_loc;
168 } GTY ((tag ("ERT_MUST_NOT_THROW"))) must_not_throw;
169 } GTY ((desc ("%0.type"))) u;
171 /* The list of landing pads associated with this region. */
172 struct eh_landing_pad_d *landing_pads;
174 /* EXC_PTR and FILTER values copied from the runtime for this region.
175 Each region gets its own psuedos so that if there are nested exceptions
176 we do not overwrite the values of the first exception. */
177 rtx exc_ptr_reg, filter_reg;
179 /* True if this region should use __cxa_end_cleanup instead
180 of _Unwind_Resume. */
181 bool use_cxa_end_cleanup;
184 typedef struct eh_landing_pad_d *eh_landing_pad;
185 typedef struct eh_catch_d *eh_catch;
186 typedef struct eh_region_d *eh_region;
191 /* The exception status for each function. */
193 struct GTY(()) eh_status
195 /* The tree of all regions for this function. */
196 eh_region region_tree;
198 /* The same information as an indexable array. */
199 vec<eh_region, va_gc> *region_array;
201 /* The landing pads as an indexable array. */
202 vec<eh_landing_pad, va_gc> *lp_array;
204 /* At the gimple level, a mapping from gimple statement to landing pad
205 or must-not-throw region. See record_stmt_eh_region. */
206 hash_map<gimple, int> *GTY(()) throw_stmt_table;
208 /* All of the runtime type data used by the function. These objects
209 are emitted to the lang-specific-data-area for the function. */
210 vec<tree, va_gc> *ttype_data;
212 /* The table of all action chains. These encode the eh_region tree in
213 a compact form for use by the runtime, and is also emitted to the
214 lang-specific-data-area. Note that the ARM EABI uses a different
215 format for the encoding than all other ports. */
216 union eh_status_u {
217 vec<tree, va_gc> *GTY((tag ("1"))) arm_eabi;
218 vec<uchar, va_gc> *GTY((tag ("0"))) other;
219 } GTY ((desc ("targetm.arm_eabi_unwinder"))) ehspec_data;
223 /* Invokes CALLBACK for every exception handler label. Only used by old
224 loop hackery; should not be used by new code. */
225 extern void for_each_eh_label (void (*) (rtx));
227 extern void init_eh_for_function (void);
229 extern void remove_eh_landing_pad (eh_landing_pad);
230 extern void remove_eh_handler (eh_region);
231 extern void remove_unreachable_eh_regions (sbitmap);
233 extern bool current_function_has_exception_handlers (void);
234 extern void output_function_exception_table (const char *);
236 extern rtx expand_builtin_eh_pointer (tree);
237 extern rtx expand_builtin_eh_filter (tree);
238 extern rtx expand_builtin_eh_copy_values (tree);
239 extern void expand_builtin_unwind_init (void);
240 extern rtx expand_builtin_eh_return_data_regno (tree);
241 extern rtx expand_builtin_extract_return_addr (tree);
242 extern void expand_builtin_init_dwarf_reg_sizes (tree);
243 extern rtx expand_builtin_frob_return_addr (tree);
244 extern rtx expand_builtin_dwarf_sp_column (void);
245 extern void expand_builtin_eh_return (tree, tree);
246 extern void expand_eh_return (void);
247 extern rtx expand_builtin_extend_pointer (tree);
248 extern void expand_dw2_landing_pad_for_region (eh_region);
250 typedef tree (*duplicate_eh_regions_map) (tree, void *);
251 extern hash_map<void *, void *> *duplicate_eh_regions
252 (struct function *, eh_region, int, duplicate_eh_regions_map, void *);
254 extern void sjlj_emit_function_exit_after (rtx_insn *);
256 extern eh_region gen_eh_region_cleanup (eh_region);
257 extern eh_region gen_eh_region_try (eh_region);
258 extern eh_region gen_eh_region_allowed (eh_region, tree);
259 extern eh_region gen_eh_region_must_not_throw (eh_region);
261 extern eh_catch gen_eh_region_catch (eh_region, tree);
262 extern eh_landing_pad gen_eh_landing_pad (eh_region);
264 extern eh_region get_eh_region_from_number_fn (struct function *, int);
265 extern eh_region get_eh_region_from_number (int);
266 extern eh_landing_pad get_eh_landing_pad_from_number_fn (struct function*,int);
267 extern eh_landing_pad get_eh_landing_pad_from_number (int);
268 extern eh_region get_eh_region_from_lp_number_fn (struct function *, int);
269 extern eh_region get_eh_region_from_lp_number (int);
271 extern eh_region eh_region_outermost (struct function *, eh_region, eh_region);
273 extern void make_reg_eh_region_note (rtx insn, int ecf_flags, int lp_nr);
274 extern void make_reg_eh_region_note_nothrow_nononlocal (rtx);
276 extern void verify_eh_tree (struct function *);
277 extern void dump_eh_tree (FILE *, struct function *);
278 void debug_eh_tree (struct function *);
279 extern void add_type_for_runtime (tree);
280 extern tree lookup_type_for_runtime (tree);
281 extern void assign_filter_values (void);
283 extern eh_region get_eh_region_from_rtx (const_rtx);
284 extern eh_landing_pad get_eh_landing_pad_from_rtx (const_rtx);
286 extern void finish_eh_generation (void);
288 struct GTY(()) throw_stmt_node {
289 gimple stmt;
290 int lp_nr;
293 extern hash_map<gimple, int> *get_eh_throw_stmt_table (struct function *);
294 extern void set_eh_throw_stmt_table (function *, hash_map<gimple, int> *);
296 enum eh_personality_kind {
297 eh_personality_none,
298 eh_personality_any,
299 eh_personality_lang
302 extern enum eh_personality_kind
303 function_needs_eh_personality (struct function *);
305 /* Pre-order iteration within the eh_region tree. */
307 static inline eh_region
308 ehr_next (eh_region r, eh_region start)
310 if (r->inner)
311 r = r->inner;
312 else if (r->next_peer && r != start)
313 r = r->next_peer;
314 else
318 r = r->outer;
319 if (r == start)
320 return NULL;
322 while (r->next_peer == NULL);
323 r = r->next_peer;
325 return r;
328 #define FOR_ALL_EH_REGION_AT(R, START) \
329 for ((R) = (START); (R) != NULL; (R) = ehr_next (R, START))
331 #define FOR_ALL_EH_REGION_FN(R, FN) \
332 for ((R) = (FN)->eh->region_tree; (R) != NULL; (R) = ehr_next (R, NULL))
334 #define FOR_ALL_EH_REGION(R) FOR_ALL_EH_REGION_FN (R, cfun)
336 #endif