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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 | ||
d05a5492 MM |
22 | #if !defined(NULL_RTX) && !defined(rtx) |
23 | typedef struct rtx_def *_except_rtx; | |
24 | #define rtx _except_rtx | |
4956d07c MS |
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 | ||
9a0d1e1b AM |
46 | LABEL_USED indicates whether a CATCH block has already used this |
47 | label or not. New ones are needed for additional catch blocks if | |
48 | it has. | |
49 | ||
911fdd58 RK |
50 | FINALIZATION is the tree codes for the handler, or is NULL_TREE if |
51 | one hasn't been generated yet, or is integer_zero_node to mark the | |
52 | end of a group of try blocks. */ | |
53 | ||
4956d07c | 54 | struct eh_entry { |
478b0752 | 55 | rtx outer_context; |
4956d07c | 56 | rtx exception_handler_label; |
4956d07c | 57 | tree finalization; |
9a0d1e1b | 58 | int label_used; |
4956d07c MS |
59 | }; |
60 | ||
911fdd58 RK |
61 | /* A list of EH_ENTRYs. ENTRY is the entry; CHAIN points to the next |
62 | entry in the list, or is NULL if this is the last entry. */ | |
63 | ||
4956d07c MS |
64 | struct eh_node { |
65 | struct eh_entry *entry; | |
66 | struct eh_node *chain; | |
67 | }; | |
68 | ||
911fdd58 RK |
69 | /* A stack of EH_ENTRYs. TOP is the topmost entry on the stack. TOP is |
70 | NULL if the stack is empty. */ | |
71 | ||
4956d07c MS |
72 | struct eh_stack { |
73 | struct eh_node *top; | |
74 | }; | |
75 | ||
911fdd58 RK |
76 | /* A queue of EH_ENTRYs. HEAD is the front of the queue; TAIL is the |
77 | end (the latest entry). HEAD and TAIL are NULL if the queue is | |
78 | empty. */ | |
79 | ||
4956d07c MS |
80 | struct eh_queue { |
81 | struct eh_node *head; | |
82 | struct eh_node *tail; | |
83 | }; | |
84 | ||
85 | ||
e976b8b2 MS |
86 | /* Start an exception handling region. All instructions emitted after |
87 | this point are considered to be part of the region until | |
88 | expand_eh_region_end () is invoked. */ | |
89 | ||
911fdd58 RK |
90 | extern void expand_eh_region_start PROTO((void)); |
91 | ||
4c581243 MS |
92 | /* Just like expand_eh_region_start, except if a cleanup action is |
93 | entered on the cleanup chain, the TREE_PURPOSE of the element put | |
94 | on the chain is DECL. DECL should be the associated VAR_DECL, if | |
95 | any, otherwise it should be NULL_TREE. */ | |
96 | ||
97 | extern void expand_eh_region_start_for_decl PROTO((tree)); | |
98 | ||
e976b8b2 MS |
99 | /* Start an exception handling region for the given cleanup action. |
100 | All instructions emitted after this point are considered to be part | |
101 | of the region until expand_eh_region_end () is invoked. CLEANUP is | |
102 | the cleanup action to perform. The return value is true if the | |
103 | exception region was optimized away. If that case, | |
104 | expand_eh_region_end does not need to be called for this cleanup, | |
105 | nor should it be. | |
106 | ||
107 | This routine notices one particular common case in C++ code | |
108 | generation, and optimizes it so as to not need the exception | |
109 | region. */ | |
110 | ||
4c581243 | 111 | extern int expand_eh_region_start_tree PROTO((tree, tree)); |
e976b8b2 MS |
112 | |
113 | /* End an exception handling region. The information about the region | |
114 | is found on the top of ehstack. | |
115 | ||
116 | HANDLER is either the cleanup for the exception region, or if we're | |
117 | marking the end of a try block, HANDLER is integer_zero_node. | |
118 | ||
119 | HANDLER will be transformed to rtl when expand_leftover_cleanups () | |
120 | is invoked. */ | |
121 | ||
911fdd58 RK |
122 | extern void expand_eh_region_end PROTO((tree)); |
123 | ||
124 | /* Push RLABEL or TLABEL onto LABELSTACK. Only one of RLABEL or TLABEL | |
125 | should be set; the other must be NULL. */ | |
126 | ||
4956d07c | 127 | extern void push_label_entry PROTO((struct label_node **labelstack, rtx rlabel, tree tlabel)); |
911fdd58 RK |
128 | |
129 | /* Pop the topmost entry from LABELSTACK and return its value as an | |
130 | rtx node. If LABELSTACK is empty, return NULL. */ | |
131 | ||
4956d07c | 132 | extern rtx pop_label_entry PROTO((struct label_node **labelstack)); |
911fdd58 RK |
133 | |
134 | /* Return the topmost entry of LABELSTACK as a tree node, or return | |
135 | NULL_TREE if LABELSTACK is empty. */ | |
136 | ||
4956d07c MS |
137 | extern tree top_label_entry PROTO((struct label_node **labelstack)); |
138 | ||
911fdd58 RK |
139 | /* A set of insns for the catch clauses in the current function. They |
140 | will be emitted at the end of the current function. */ | |
141 | ||
4956d07c | 142 | extern rtx catch_clauses; |
4956d07c MS |
143 | |
144 | #endif | |
145 | ||
d6f4ec51 KG |
146 | /* Test: is exception handling turned on? */ |
147 | ||
148 | extern int doing_eh PROTO ((int)); | |
149 | ||
911fdd58 RK |
150 | /* Toplevel initialization for EH. */ |
151 | ||
9a0d1e1b AM |
152 | #ifdef NEW_EH_MODEL |
153 | ||
154 | void set_exception_lang_code PROTO((short)); | |
155 | void set_exception_version_code PROTO((short)); | |
156 | ||
157 | #endif | |
158 | ||
159 | /* A list of handlers asocciated with an exception region. HANDLER_LABEL | |
160 | is the the label that control should be transfered to if the data | |
161 | in TYPE_INFO matches an exception. a value of NULL_TREE for TYPE_INFO | |
162 | means This is a cleanup, and must always be called. A value of | |
163 | CATCH_ALL_TYPE works like a cleanup, but a call to the runtime matcher | |
164 | is still performed to avoid being caught by a different language | |
165 | exception. NEXT is a pointer to the next handler for this region. | |
166 | NULL means there are no more. */ | |
167 | ||
168 | #define CATCH_ALL_TYPE (tree *) -1 | |
169 | ||
170 | typedef struct handler_info | |
171 | { | |
172 | rtx handler_label; | |
173 | void *type_info; | |
174 | struct handler_info *next; | |
175 | } handler_info; | |
176 | ||
177 | ||
178 | /* Add a new eh_entry for this function, The parameter specifies what | |
179 | exception region number NOTE insns use to delimit this range. | |
180 | The integer returned is uniquely identifies this exception range | |
181 | within an internal table. */ | |
182 | ||
183 | int new_eh_region_entry PROTO((int)); | |
184 | ||
185 | /* Add new handler information to an exception range. The first parameter | |
186 | specifies the range number (returned from new_eh_entry()). The second | |
187 | parameter specifies the handler. By default the handler is inserted at | |
188 | the end of the list. A handler list may contain only ONE NULL_TREE | |
189 | typeinfo entry. Regardless where it is positioned, a NULL_TREE entry | |
190 | is always output as the LAST handler in the exception table for a region. */ | |
191 | ||
192 | void add_new_handler PROTO((int, struct handler_info *)); | |
193 | ||
9f8e6243 AM |
194 | /* Remove a handler label. The handler label is being deleted, so all |
195 | regions which reference this handler should have it removed from their | |
196 | list of possible handlers. Any region which has the final handler | |
197 | removed can be deleted. */ | |
198 | ||
199 | void remove_handler PROTO((rtx)); | |
200 | ||
9a0d1e1b AM |
201 | /* Create a new handler structure initialized with the handler label and |
202 | typeinfo fields passed in. */ | |
203 | ||
204 | struct handler_info *get_new_handler PROTO((rtx, void *)); | |
205 | ||
206 | /* Make a duplicate of an exception region by copying all the handlers | |
207 | for an exception region. Return the new handler index. */ | |
208 | ||
209 | int duplicate_handlers PROTO((int, int)); | |
210 | ||
211 | ||
212 | /* Get a pointer to the first handler in an exception region's list. */ | |
213 | ||
214 | struct handler_info *get_first_handler PROTO((int)); | |
215 | ||
216 | ||
4956d07c | 217 | extern void init_eh PROTO((void)); |
911fdd58 RK |
218 | |
219 | /* Initialization for the per-function EH data. */ | |
220 | ||
4956d07c | 221 | extern void init_eh_for_function PROTO((void)); |
911fdd58 | 222 | |
9a0d1e1b AM |
223 | /* Generate an exception label. Use instead of gen_label_rtx */ |
224 | ||
225 | extern rtx gen_exception_label PROTO((void)); | |
226 | ||
911fdd58 RK |
227 | /* Adds an EH table entry for EH entry number N. Called from |
228 | final_scan_insn for NOTE_INSN_EH_REGION_BEG. */ | |
229 | ||
230 | extern void add_eh_table_entry PROTO((int n)); | |
231 | ||
9a0d1e1b AM |
232 | /* Start a catch clause, triggered by runtime value paramter. */ |
233 | ||
234 | #ifdef TREE_CODE | |
235 | extern void expand_start_catch PROTO((tree)); | |
236 | #endif | |
237 | ||
238 | /* End a catch clause. */ | |
239 | ||
240 | extern void expand_end_catch PROTO((void)); | |
241 | ||
911fdd58 RK |
242 | /* Returns a non-zero value if we need to output an exception table. */ |
243 | ||
4956d07c | 244 | extern int exception_table_p PROTO((void)); |
911fdd58 RK |
245 | |
246 | /* Outputs the exception table if we have one. */ | |
247 | ||
4956d07c | 248 | extern void output_exception_table PROTO((void)); |
911fdd58 RK |
249 | |
250 | /* Given a return address in ADDR, determine the address we should use | |
251 | to find the corresponding EH region. */ | |
252 | ||
253 | extern rtx eh_outer_context PROTO((rtx addr)); | |
254 | ||
255 | /* Called at the start of a block of try statements for which there is | |
256 | a supplied catch handler. */ | |
257 | ||
258 | extern void expand_start_try_stmts PROTO((void)); | |
259 | ||
260 | /* Called at the start of a block of catch statements. It terminates the | |
261 | previous set of try statements. */ | |
262 | ||
263 | extern void expand_start_all_catch PROTO((void)); | |
264 | ||
265 | /* Called at the end of a block of catch statements. */ | |
266 | ||
267 | extern void expand_end_all_catch PROTO((void)); | |
268 | ||
269 | #ifdef TREE_CODE | |
270 | /* Create a new exception region and add the handler for the region | |
271 | onto a list. These regions will be ended (and their handlers | |
272 | emitted) when end_protect_partials is invoked. */ | |
273 | ||
274 | extern void add_partial_entry PROTO((tree handler)); | |
275 | #endif | |
276 | ||
277 | /* End all of the pending exception regions that have handlers added with | |
278 | push_protect_entry (). */ | |
279 | ||
280 | extern void end_protect_partials PROTO((void)); | |
281 | ||
e701eb4d | 282 | /* An internal throw. */ |
911fdd58 | 283 | |
e701eb4d | 284 | extern void expand_internal_throw PROTO((void)); |
911fdd58 RK |
285 | |
286 | /* Called from expand_exception_blocks and expand_end_catch_block to | |
287 | expand and pending handlers. */ | |
288 | ||
289 | extern void expand_leftover_cleanups PROTO((void)); | |
290 | ||
154bba13 TT |
291 | /* If necessary, emit insns to get EH context for the current |
292 | function. */ | |
293 | ||
294 | extern void emit_eh_context PROTO((void)); | |
295 | ||
911fdd58 RK |
296 | /* If necessary, emit insns for the start of per-function unwinder for |
297 | the current function. */ | |
298 | ||
4956d07c | 299 | extern void emit_unwinder PROTO((void)); |
911fdd58 RK |
300 | |
301 | /* If necessary, emit insns for the end of the per-function unwinder | |
302 | for the current function. */ | |
303 | ||
4956d07c | 304 | extern void end_eh_unwinder PROTO((void)); |
4956d07c | 305 | |
911fdd58 RK |
306 | /* Builds a list of handler labels and puts them in the global |
307 | variable exception_handler_labels. */ | |
308 | ||
309 | extern void find_exception_handler_labels PROTO((void)); | |
310 | ||
9a0d1e1b AM |
311 | /* Determine if an arbitrary label is an exception label */ |
312 | ||
313 | extern int is_exception_handler_label PROTO((int)); | |
314 | ||
911fdd58 RK |
315 | /* Performs sanity checking on the check_exception_handler_labels |
316 | list. */ | |
317 | ||
318 | extern void check_exception_handler_labels PROTO((void)); | |
319 | ||
320 | /* A stack used to keep track of the label used to resume normal program | |
321 | flow out of the current exception handler region. */ | |
4956d07c MS |
322 | |
323 | extern struct label_node *caught_return_label_stack; | |
911fdd58 | 324 | |
956d6950 JL |
325 | /* Keeps track of the label used as the context of a throw to rethrow an |
326 | exception to the outer exception region. */ | |
327 | ||
328 | extern struct label_node *outer_context_label_stack; | |
329 | ||
911fdd58 RK |
330 | /* A random area used for purposes elsewhere. */ |
331 | ||
4956d07c MS |
332 | extern struct label_node *false_label_stack; |
333 | ||
911fdd58 RK |
334 | /* A list of labels used for exception handlers. It is created by |
335 | find_exception_handler_labels for the optimization passes. */ | |
336 | ||
4956d07c MS |
337 | extern rtx exception_handler_labels; |
338 | ||
911fdd58 RK |
339 | /* Performs optimizations for exception handling, such as removing |
340 | unnecessary exception regions. Invoked from jump_optimize (). */ | |
341 | ||
4956d07c | 342 | extern void exception_optimize PROTO((void)); |
e976b8b2 | 343 | |
01eb7f9a | 344 | /* Return EH context (and set it up once per fn). */ |
154bba13 TT |
345 | extern rtx get_eh_context PROTO((void)); |
346 | ||
e976b8b2 MS |
347 | /* Get the dynamic handler chain. */ |
348 | extern rtx get_dynamic_handler_chain PROTO((void)); | |
349 | ||
350 | /* Get the dynamic cleanup chain. */ | |
351 | extern rtx get_dynamic_cleanup_chain PROTO((void)); | |
352 | ||
353 | /* Throw an exception. */ | |
354 | ||
355 | extern void emit_throw PROTO((void)); | |
356 | ||
357 | /* One to use setjmp/longjmp method of generating code. */ | |
358 | ||
359 | extern int exceptions_via_longjmp; | |
360 | ||
361 | /* One to enable asynchronous exception support. */ | |
362 | ||
363 | extern int asynchronous_exceptions; | |
364 | ||
365 | /* One to protect cleanup actions with a handler that calls | |
366 | __terminate, zero otherwise. */ | |
367 | ||
368 | extern int protect_cleanup_actions_with_terminate; | |
369 | ||
370 | #ifdef TREE_CODE | |
371 | extern tree protect_with_terminate PROTO((tree)); | |
372 | #endif | |
0021b564 | 373 | |
487a6e06 KG |
374 | extern void expand_fixup_region_start PROTO((void)); |
375 | #ifdef TREE_CODE | |
376 | extern void expand_fixup_region_end PROTO((tree)); | |
377 | #endif | |
378 | ||
0021b564 JM |
379 | /* Various hooks for the DWARF 2 __throw routine. */ |
380 | ||
381 | void expand_builtin_unwind_init PROTO((void)); | |
382 | rtx expand_builtin_dwarf_fp_regnum PROTO((void)); | |
383 | rtx expand_builtin_eh_stub PROTO((void)); | |
384 | #ifdef TREE_CODE | |
385 | rtx expand_builtin_frob_return_addr PROTO((tree)); | |
386 | rtx expand_builtin_extract_return_addr PROTO((tree)); | |
387 | void expand_builtin_set_return_addr_reg PROTO((tree)); | |
388 | void expand_builtin_set_eh_regs PROTO((tree, tree)); | |
2f3ca9e7 | 389 | rtx expand_builtin_dwarf_reg_size PROTO((tree, rtx)); |
0021b564 | 390 | #endif |
5aa55043 AM |
391 | |
392 | ||
393 | /* Checking whether 2 instructions are within the same exception region. */ | |
394 | ||
395 | int in_same_eh_region PROTO((rtx, rtx)); | |
396 | void free_insn_eh_region PROTO((void)); | |
397 | void init_insn_eh_region PROTO((rtx, int)); | |
d05a5492 MM |
398 | |
399 | #ifdef rtx | |
400 | #undef rtx | |
401 | #endif |