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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 | void set_exception_lang_code PROTO((short)); |
153 | void set_exception_version_code PROTO((short)); | |
154 | ||
9a0d1e1b AM |
155 | /* A list of handlers asocciated with an exception region. HANDLER_LABEL |
156 | is the the label that control should be transfered to if the data | |
157 | in TYPE_INFO matches an exception. a value of NULL_TREE for TYPE_INFO | |
158 | means This is a cleanup, and must always be called. A value of | |
159 | CATCH_ALL_TYPE works like a cleanup, but a call to the runtime matcher | |
160 | is still performed to avoid being caught by a different language | |
161 | exception. NEXT is a pointer to the next handler for this region. | |
162 | NULL means there are no more. */ | |
163 | ||
164 | #define CATCH_ALL_TYPE (tree *) -1 | |
165 | ||
166 | typedef struct handler_info | |
167 | { | |
168 | rtx handler_label; | |
169 | void *type_info; | |
170 | struct handler_info *next; | |
171 | } handler_info; | |
172 | ||
173 | ||
174 | /* Add a new eh_entry for this function, The parameter specifies what | |
175 | exception region number NOTE insns use to delimit this range. | |
176 | The integer returned is uniquely identifies this exception range | |
177 | within an internal table. */ | |
178 | ||
179 | int new_eh_region_entry PROTO((int)); | |
180 | ||
181 | /* Add new handler information to an exception range. The first parameter | |
182 | specifies the range number (returned from new_eh_entry()). The second | |
183 | parameter specifies the handler. By default the handler is inserted at | |
184 | the end of the list. A handler list may contain only ONE NULL_TREE | |
185 | typeinfo entry. Regardless where it is positioned, a NULL_TREE entry | |
186 | is always output as the LAST handler in the exception table for a region. */ | |
187 | ||
188 | void add_new_handler PROTO((int, struct handler_info *)); | |
189 | ||
9f8e6243 AM |
190 | /* Remove a handler label. The handler label is being deleted, so all |
191 | regions which reference this handler should have it removed from their | |
192 | list of possible handlers. Any region which has the final handler | |
193 | removed can be deleted. */ | |
194 | ||
195 | void remove_handler PROTO((rtx)); | |
196 | ||
9a0d1e1b AM |
197 | /* Create a new handler structure initialized with the handler label and |
198 | typeinfo fields passed in. */ | |
199 | ||
200 | struct handler_info *get_new_handler PROTO((rtx, void *)); | |
201 | ||
202 | /* Make a duplicate of an exception region by copying all the handlers | |
203 | for an exception region. Return the new handler index. */ | |
204 | ||
205 | int duplicate_handlers PROTO((int, int)); | |
206 | ||
207 | ||
208 | /* Get a pointer to the first handler in an exception region's list. */ | |
209 | ||
210 | struct handler_info *get_first_handler PROTO((int)); | |
211 | ||
212 | ||
4956d07c | 213 | extern void init_eh PROTO((void)); |
911fdd58 RK |
214 | |
215 | /* Initialization for the per-function EH data. */ | |
216 | ||
4956d07c | 217 | extern void init_eh_for_function PROTO((void)); |
911fdd58 | 218 | |
9a0d1e1b AM |
219 | /* Generate an exception label. Use instead of gen_label_rtx */ |
220 | ||
221 | extern rtx gen_exception_label PROTO((void)); | |
222 | ||
911fdd58 RK |
223 | /* Adds an EH table entry for EH entry number N. Called from |
224 | final_scan_insn for NOTE_INSN_EH_REGION_BEG. */ | |
225 | ||
226 | extern void add_eh_table_entry PROTO((int n)); | |
227 | ||
9a0d1e1b AM |
228 | /* Start a catch clause, triggered by runtime value paramter. */ |
229 | ||
230 | #ifdef TREE_CODE | |
0d3453df | 231 | extern void start_catch_handler PROTO((tree)); |
9a0d1e1b AM |
232 | #endif |
233 | ||
911fdd58 RK |
234 | /* Returns a non-zero value if we need to output an exception table. */ |
235 | ||
4956d07c | 236 | extern int exception_table_p PROTO((void)); |
911fdd58 RK |
237 | |
238 | /* Outputs the exception table if we have one. */ | |
239 | ||
4956d07c | 240 | extern void output_exception_table PROTO((void)); |
911fdd58 RK |
241 | |
242 | /* Given a return address in ADDR, determine the address we should use | |
243 | to find the corresponding EH region. */ | |
244 | ||
245 | extern rtx eh_outer_context PROTO((rtx addr)); | |
246 | ||
247 | /* Called at the start of a block of try statements for which there is | |
248 | a supplied catch handler. */ | |
249 | ||
250 | extern void expand_start_try_stmts PROTO((void)); | |
251 | ||
252 | /* Called at the start of a block of catch statements. It terminates the | |
253 | previous set of try statements. */ | |
254 | ||
255 | extern void expand_start_all_catch PROTO((void)); | |
256 | ||
257 | /* Called at the end of a block of catch statements. */ | |
258 | ||
259 | extern void expand_end_all_catch PROTO((void)); | |
260 | ||
261 | #ifdef TREE_CODE | |
262 | /* Create a new exception region and add the handler for the region | |
263 | onto a list. These regions will be ended (and their handlers | |
264 | emitted) when end_protect_partials is invoked. */ | |
265 | ||
266 | extern void add_partial_entry PROTO((tree handler)); | |
267 | #endif | |
268 | ||
269 | /* End all of the pending exception regions that have handlers added with | |
270 | push_protect_entry (). */ | |
271 | ||
272 | extern void end_protect_partials PROTO((void)); | |
273 | ||
e701eb4d | 274 | /* An internal throw. */ |
911fdd58 | 275 | |
e701eb4d | 276 | extern void expand_internal_throw PROTO((void)); |
911fdd58 RK |
277 | |
278 | /* Called from expand_exception_blocks and expand_end_catch_block to | |
279 | expand and pending handlers. */ | |
280 | ||
281 | extern void expand_leftover_cleanups PROTO((void)); | |
282 | ||
154bba13 TT |
283 | /* If necessary, emit insns to get EH context for the current |
284 | function. */ | |
285 | ||
286 | extern void emit_eh_context PROTO((void)); | |
287 | ||
911fdd58 RK |
288 | /* Builds a list of handler labels and puts them in the global |
289 | variable exception_handler_labels. */ | |
290 | ||
291 | extern void find_exception_handler_labels PROTO((void)); | |
292 | ||
9a0d1e1b AM |
293 | /* Determine if an arbitrary label is an exception label */ |
294 | ||
295 | extern int is_exception_handler_label PROTO((int)); | |
296 | ||
911fdd58 RK |
297 | /* Performs sanity checking on the check_exception_handler_labels |
298 | list. */ | |
299 | ||
300 | extern void check_exception_handler_labels PROTO((void)); | |
301 | ||
302 | /* A stack used to keep track of the label used to resume normal program | |
303 | flow out of the current exception handler region. */ | |
4956d07c MS |
304 | |
305 | extern struct label_node *caught_return_label_stack; | |
911fdd58 | 306 | |
956d6950 JL |
307 | /* Keeps track of the label used as the context of a throw to rethrow an |
308 | exception to the outer exception region. */ | |
309 | ||
310 | extern struct label_node *outer_context_label_stack; | |
311 | ||
911fdd58 RK |
312 | /* A random area used for purposes elsewhere. */ |
313 | ||
4956d07c MS |
314 | extern struct label_node *false_label_stack; |
315 | ||
911fdd58 RK |
316 | /* A list of labels used for exception handlers. It is created by |
317 | find_exception_handler_labels for the optimization passes. */ | |
318 | ||
4956d07c MS |
319 | extern rtx exception_handler_labels; |
320 | ||
911fdd58 RK |
321 | /* Performs optimizations for exception handling, such as removing |
322 | unnecessary exception regions. Invoked from jump_optimize (). */ | |
323 | ||
4956d07c | 324 | extern void exception_optimize PROTO((void)); |
e976b8b2 | 325 | |
01eb7f9a | 326 | /* Return EH context (and set it up once per fn). */ |
154bba13 TT |
327 | extern rtx get_eh_context PROTO((void)); |
328 | ||
e976b8b2 MS |
329 | /* Get the dynamic handler chain. */ |
330 | extern rtx get_dynamic_handler_chain PROTO((void)); | |
331 | ||
332 | /* Get the dynamic cleanup chain. */ | |
333 | extern rtx get_dynamic_cleanup_chain PROTO((void)); | |
334 | ||
335 | /* Throw an exception. */ | |
336 | ||
337 | extern void emit_throw PROTO((void)); | |
338 | ||
339 | /* One to use setjmp/longjmp method of generating code. */ | |
340 | ||
341 | extern int exceptions_via_longjmp; | |
342 | ||
343 | /* One to enable asynchronous exception support. */ | |
344 | ||
345 | extern int asynchronous_exceptions; | |
346 | ||
347 | /* One to protect cleanup actions with a handler that calls | |
348 | __terminate, zero otherwise. */ | |
349 | ||
350 | extern int protect_cleanup_actions_with_terminate; | |
351 | ||
352 | #ifdef TREE_CODE | |
353 | extern tree protect_with_terminate PROTO((tree)); | |
354 | #endif | |
0021b564 | 355 | |
487a6e06 KG |
356 | extern void expand_fixup_region_start PROTO((void)); |
357 | #ifdef TREE_CODE | |
358 | extern void expand_fixup_region_end PROTO((tree)); | |
359 | #endif | |
360 | ||
0021b564 JM |
361 | /* Various hooks for the DWARF 2 __throw routine. */ |
362 | ||
363 | void expand_builtin_unwind_init PROTO((void)); | |
364 | rtx expand_builtin_dwarf_fp_regnum PROTO((void)); | |
365 | rtx expand_builtin_eh_stub PROTO((void)); | |
a1622f83 | 366 | rtx expand_builtin_eh_stub_old PROTO((void)); |
0021b564 JM |
367 | #ifdef TREE_CODE |
368 | rtx expand_builtin_frob_return_addr PROTO((tree)); | |
369 | rtx expand_builtin_extract_return_addr PROTO((tree)); | |
370 | void expand_builtin_set_return_addr_reg PROTO((tree)); | |
371 | void expand_builtin_set_eh_regs PROTO((tree, tree)); | |
2f3ca9e7 | 372 | rtx expand_builtin_dwarf_reg_size PROTO((tree, rtx)); |
0021b564 | 373 | #endif |
5aa55043 AM |
374 | |
375 | ||
376 | /* Checking whether 2 instructions are within the same exception region. */ | |
377 | ||
378 | int in_same_eh_region PROTO((rtx, rtx)); | |
379 | void free_insn_eh_region PROTO((void)); | |
380 | void init_insn_eh_region PROTO((rtx, int)); | |
d05a5492 MM |
381 | |
382 | #ifdef rtx | |
383 | #undef rtx | |
384 | #endif |