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4956d07c | 1 | /* Exception Handling interface routines. |
e9a25f70 | 2 | Copyright (C) 1996, 1997 Free Software Foundation, Inc. |
4956d07c MS |
3 | Contributed by Mike Stump <mrs@cygnus.com>. |
4 | ||
5 | This file is part of GNU CC. | |
6 | ||
7 | GNU CC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GNU CC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU CC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | ||
23 | #ifndef GET_CODE | |
24 | #define rtx int * | |
25 | #endif | |
26 | ||
27 | #ifdef TREE_CODE | |
28 | ||
911fdd58 RK |
29 | /* A stack of labels. CHAIN points to the next entry in the stack. */ |
30 | ||
4956d07c MS |
31 | struct label_node { |
32 | union { | |
33 | rtx rlabel; | |
34 | tree tlabel; | |
35 | } u; | |
36 | struct label_node *chain; | |
37 | }; | |
38 | ||
911fdd58 RK |
39 | /* An eh_entry is used to describe one exception handling region. |
40 | ||
478b0752 | 41 | OUTER_CONTEXT is the label used for rethrowing into the outer context. |
911fdd58 RK |
42 | |
43 | EXCEPTION_HANDLER_LABEL is the label corresponding to the handler | |
44 | for this region. | |
45 | ||
46 | FINALIZATION is the tree codes for the handler, or is NULL_TREE if | |
47 | one hasn't been generated yet, or is integer_zero_node to mark the | |
48 | end of a group of try blocks. */ | |
49 | ||
4956d07c | 50 | struct eh_entry { |
478b0752 | 51 | rtx outer_context; |
4956d07c MS |
52 | rtx exception_handler_label; |
53 | ||
54 | tree finalization; | |
55 | }; | |
56 | ||
911fdd58 RK |
57 | /* A list of EH_ENTRYs. ENTRY is the entry; CHAIN points to the next |
58 | entry in the list, or is NULL if this is the last entry. */ | |
59 | ||
4956d07c MS |
60 | struct eh_node { |
61 | struct eh_entry *entry; | |
62 | struct eh_node *chain; | |
63 | }; | |
64 | ||
911fdd58 RK |
65 | /* A stack of EH_ENTRYs. TOP is the topmost entry on the stack. TOP is |
66 | NULL if the stack is empty. */ | |
67 | ||
4956d07c MS |
68 | struct eh_stack { |
69 | struct eh_node *top; | |
70 | }; | |
71 | ||
911fdd58 RK |
72 | /* A queue of EH_ENTRYs. HEAD is the front of the queue; TAIL is the |
73 | end (the latest entry). HEAD and TAIL are NULL if the queue is | |
74 | empty. */ | |
75 | ||
4956d07c MS |
76 | struct eh_queue { |
77 | struct eh_node *head; | |
78 | struct eh_node *tail; | |
79 | }; | |
80 | ||
81 | ||
e976b8b2 MS |
82 | /* Start an exception handling region. All instructions emitted after |
83 | this point are considered to be part of the region until | |
84 | expand_eh_region_end () is invoked. */ | |
85 | ||
911fdd58 RK |
86 | extern void expand_eh_region_start PROTO((void)); |
87 | ||
4c581243 MS |
88 | /* Just like expand_eh_region_start, except if a cleanup action is |
89 | entered on the cleanup chain, the TREE_PURPOSE of the element put | |
90 | on the chain is DECL. DECL should be the associated VAR_DECL, if | |
91 | any, otherwise it should be NULL_TREE. */ | |
92 | ||
93 | extern void expand_eh_region_start_for_decl PROTO((tree)); | |
94 | ||
e976b8b2 MS |
95 | /* Start an exception handling region for the given cleanup action. |
96 | All instructions emitted after this point are considered to be part | |
97 | of the region until expand_eh_region_end () is invoked. CLEANUP is | |
98 | the cleanup action to perform. The return value is true if the | |
99 | exception region was optimized away. If that case, | |
100 | expand_eh_region_end does not need to be called for this cleanup, | |
101 | nor should it be. | |
102 | ||
103 | This routine notices one particular common case in C++ code | |
104 | generation, and optimizes it so as to not need the exception | |
105 | region. */ | |
106 | ||
4c581243 | 107 | extern int expand_eh_region_start_tree PROTO((tree, tree)); |
e976b8b2 MS |
108 | |
109 | /* End an exception handling region. The information about the region | |
110 | is found on the top of ehstack. | |
111 | ||
112 | HANDLER is either the cleanup for the exception region, or if we're | |
113 | marking the end of a try block, HANDLER is integer_zero_node. | |
114 | ||
115 | HANDLER will be transformed to rtl when expand_leftover_cleanups () | |
116 | is invoked. */ | |
117 | ||
911fdd58 RK |
118 | extern void expand_eh_region_end PROTO((tree)); |
119 | ||
120 | /* Push RLABEL or TLABEL onto LABELSTACK. Only one of RLABEL or TLABEL | |
121 | should be set; the other must be NULL. */ | |
122 | ||
4956d07c | 123 | extern void push_label_entry PROTO((struct label_node **labelstack, rtx rlabel, tree tlabel)); |
911fdd58 RK |
124 | |
125 | /* Pop the topmost entry from LABELSTACK and return its value as an | |
126 | rtx node. If LABELSTACK is empty, return NULL. */ | |
127 | ||
4956d07c | 128 | extern rtx pop_label_entry PROTO((struct label_node **labelstack)); |
911fdd58 RK |
129 | |
130 | /* Return the topmost entry of LABELSTACK as a tree node, or return | |
131 | NULL_TREE if LABELSTACK is empty. */ | |
132 | ||
4956d07c MS |
133 | extern tree top_label_entry PROTO((struct label_node **labelstack)); |
134 | ||
911fdd58 RK |
135 | /* A set of insns for the catch clauses in the current function. They |
136 | will be emitted at the end of the current function. */ | |
137 | ||
4956d07c | 138 | extern rtx catch_clauses; |
4956d07c MS |
139 | |
140 | #endif | |
141 | ||
d6f4ec51 KG |
142 | /* Test: is exception handling turned on? */ |
143 | ||
144 | extern int doing_eh PROTO ((int)); | |
145 | ||
911fdd58 RK |
146 | /* Toplevel initialization for EH. */ |
147 | ||
4956d07c | 148 | extern void init_eh PROTO((void)); |
911fdd58 RK |
149 | |
150 | /* Initialization for the per-function EH data. */ | |
151 | ||
4956d07c | 152 | extern void init_eh_for_function PROTO((void)); |
911fdd58 | 153 | |
911fdd58 RK |
154 | /* Adds an EH table entry for EH entry number N. Called from |
155 | final_scan_insn for NOTE_INSN_EH_REGION_BEG. */ | |
156 | ||
157 | extern void add_eh_table_entry PROTO((int n)); | |
158 | ||
159 | /* Returns a non-zero value if we need to output an exception table. */ | |
160 | ||
4956d07c | 161 | extern int exception_table_p PROTO((void)); |
911fdd58 RK |
162 | |
163 | /* Outputs the exception table if we have one. */ | |
164 | ||
4956d07c | 165 | extern void output_exception_table PROTO((void)); |
911fdd58 RK |
166 | |
167 | /* Given a return address in ADDR, determine the address we should use | |
168 | to find the corresponding EH region. */ | |
169 | ||
170 | extern rtx eh_outer_context PROTO((rtx addr)); | |
171 | ||
172 | /* Called at the start of a block of try statements for which there is | |
173 | a supplied catch handler. */ | |
174 | ||
175 | extern void expand_start_try_stmts PROTO((void)); | |
176 | ||
177 | /* Called at the start of a block of catch statements. It terminates the | |
178 | previous set of try statements. */ | |
179 | ||
180 | extern void expand_start_all_catch PROTO((void)); | |
181 | ||
182 | /* Called at the end of a block of catch statements. */ | |
183 | ||
184 | extern void expand_end_all_catch PROTO((void)); | |
185 | ||
186 | #ifdef TREE_CODE | |
187 | /* Create a new exception region and add the handler for the region | |
188 | onto a list. These regions will be ended (and their handlers | |
189 | emitted) when end_protect_partials is invoked. */ | |
190 | ||
191 | extern void add_partial_entry PROTO((tree handler)); | |
192 | #endif | |
193 | ||
194 | /* End all of the pending exception regions that have handlers added with | |
195 | push_protect_entry (). */ | |
196 | ||
197 | extern void end_protect_partials PROTO((void)); | |
198 | ||
e701eb4d | 199 | /* An internal throw. */ |
911fdd58 | 200 | |
e701eb4d | 201 | extern void expand_internal_throw PROTO((void)); |
911fdd58 RK |
202 | |
203 | /* Called from expand_exception_blocks and expand_end_catch_block to | |
204 | expand and pending handlers. */ | |
205 | ||
206 | extern void expand_leftover_cleanups PROTO((void)); | |
207 | ||
154bba13 TT |
208 | /* If necessary, emit insns to get EH context for the current |
209 | function. */ | |
210 | ||
211 | extern void emit_eh_context PROTO((void)); | |
212 | ||
911fdd58 RK |
213 | /* If necessary, emit insns for the start of per-function unwinder for |
214 | the current function. */ | |
215 | ||
4956d07c | 216 | extern void emit_unwinder PROTO((void)); |
911fdd58 RK |
217 | |
218 | /* If necessary, emit insns for the end of the per-function unwinder | |
219 | for the current function. */ | |
220 | ||
4956d07c | 221 | extern void end_eh_unwinder PROTO((void)); |
4956d07c | 222 | |
911fdd58 RK |
223 | /* Builds a list of handler labels and puts them in the global |
224 | variable exception_handler_labels. */ | |
225 | ||
226 | extern void find_exception_handler_labels PROTO((void)); | |
227 | ||
228 | /* Performs sanity checking on the check_exception_handler_labels | |
229 | list. */ | |
230 | ||
231 | extern void check_exception_handler_labels PROTO((void)); | |
232 | ||
233 | /* A stack used to keep track of the label used to resume normal program | |
234 | flow out of the current exception handler region. */ | |
4956d07c MS |
235 | |
236 | extern struct label_node *caught_return_label_stack; | |
911fdd58 | 237 | |
956d6950 JL |
238 | /* Keeps track of the label used as the context of a throw to rethrow an |
239 | exception to the outer exception region. */ | |
240 | ||
241 | extern struct label_node *outer_context_label_stack; | |
242 | ||
911fdd58 RK |
243 | /* A random area used for purposes elsewhere. */ |
244 | ||
4956d07c MS |
245 | extern struct label_node *false_label_stack; |
246 | ||
911fdd58 RK |
247 | /* A list of labels used for exception handlers. It is created by |
248 | find_exception_handler_labels for the optimization passes. */ | |
249 | ||
4956d07c MS |
250 | extern rtx exception_handler_labels; |
251 | ||
911fdd58 RK |
252 | /* Performs optimizations for exception handling, such as removing |
253 | unnecessary exception regions. Invoked from jump_optimize (). */ | |
254 | ||
4956d07c | 255 | extern void exception_optimize PROTO((void)); |
e976b8b2 | 256 | |
01eb7f9a | 257 | /* Return EH context (and set it up once per fn). */ |
154bba13 TT |
258 | extern rtx get_eh_context PROTO((void)); |
259 | ||
e976b8b2 MS |
260 | /* Get the dynamic handler chain. */ |
261 | extern rtx get_dynamic_handler_chain PROTO((void)); | |
262 | ||
263 | /* Get the dynamic cleanup chain. */ | |
264 | extern rtx get_dynamic_cleanup_chain PROTO((void)); | |
265 | ||
266 | /* Throw an exception. */ | |
267 | ||
268 | extern void emit_throw PROTO((void)); | |
269 | ||
270 | /* One to use setjmp/longjmp method of generating code. */ | |
271 | ||
272 | extern int exceptions_via_longjmp; | |
273 | ||
274 | /* One to enable asynchronous exception support. */ | |
275 | ||
276 | extern int asynchronous_exceptions; | |
277 | ||
278 | /* One to protect cleanup actions with a handler that calls | |
279 | __terminate, zero otherwise. */ | |
280 | ||
281 | extern int protect_cleanup_actions_with_terminate; | |
282 | ||
283 | #ifdef TREE_CODE | |
284 | extern tree protect_with_terminate PROTO((tree)); | |
285 | #endif | |
0021b564 JM |
286 | |
287 | /* Various hooks for the DWARF 2 __throw routine. */ | |
288 | ||
289 | void expand_builtin_unwind_init PROTO((void)); | |
290 | rtx expand_builtin_dwarf_fp_regnum PROTO((void)); | |
291 | rtx expand_builtin_eh_stub PROTO((void)); | |
292 | #ifdef TREE_CODE | |
293 | rtx expand_builtin_frob_return_addr PROTO((tree)); | |
294 | rtx expand_builtin_extract_return_addr PROTO((tree)); | |
295 | void expand_builtin_set_return_addr_reg PROTO((tree)); | |
296 | void expand_builtin_set_eh_regs PROTO((tree, tree)); | |
2f3ca9e7 | 297 | rtx expand_builtin_dwarf_reg_size PROTO((tree, rtx)); |
0021b564 | 298 | #endif |
5aa55043 AM |
299 | |
300 | ||
301 | /* Checking whether 2 instructions are within the same exception region. */ | |
302 | ||
303 | int in_same_eh_region PROTO((rtx, rtx)); | |
304 | void free_insn_eh_region PROTO((void)); | |
305 | void init_insn_eh_region PROTO((rtx, int)); |