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8d08fdba | 1 | /* Handle exceptional things in C++. |
c913b6f1 | 2 | Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, |
4227d4a1 | 3 | 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010 |
448083e5 | 4 | Free Software Foundation, Inc. |
8d2733ca MS |
5 | Contributed by Michael Tiemann <tiemann@cygnus.com> |
6 | Rewritten by Mike Stump <mrs@cygnus.com>, based upon an | |
7 | initial re-implementation courtesy Tad Hunt. | |
8d08fdba | 8 | |
f5adbb8d | 9 | This file is part of GCC. |
8d08fdba | 10 | |
f5adbb8d | 11 | GCC is free software; you can redistribute it and/or modify |
8d08fdba | 12 | it under the terms of the GNU General Public License as published by |
e77f031d | 13 | the Free Software Foundation; either version 3, or (at your option) |
8d08fdba MS |
14 | any later version. |
15 | ||
f5adbb8d | 16 | GCC is distributed in the hope that it will be useful, |
8d08fdba MS |
17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | GNU General Public License for more details. | |
20 | ||
21 | You should have received a copy of the GNU General Public License | |
e77f031d NC |
22 | along with GCC; see the file COPYING3. If not see |
23 | <http://www.gnu.org/licenses/>. */ | |
8d08fdba MS |
24 | |
25 | ||
8d08fdba | 26 | #include "config.h" |
8d052bc7 | 27 | #include "system.h" |
4977bab6 ZW |
28 | #include "coretypes.h" |
29 | #include "tm.h" | |
8d08fdba | 30 | #include "tree.h" |
8d08fdba MS |
31 | #include "cp-tree.h" |
32 | #include "flags.h" | |
21451173 | 33 | #include "output.h" |
6f30f1f1 | 34 | #include "tree-inline.h" |
325c3691 | 35 | #include "tree-iterator.h" |
617a1b71 | 36 | #include "target.h" |
726a989a | 37 | #include "gimple.h" |
8d08fdba | 38 | |
5cc3d3b8 GDR |
39 | static void push_eh_cleanup (tree); |
40 | static tree prepare_eh_type (tree); | |
5cc3d3b8 GDR |
41 | static tree do_begin_catch (void); |
42 | static int dtor_nothrow (tree); | |
43 | static tree do_end_catch (tree); | |
5cc3d3b8 GDR |
44 | static bool decl_is_java_type (tree decl, int err); |
45 | static void initialize_handler_parm (tree, tree); | |
46 | static tree do_allocate_exception (tree); | |
5cc3d3b8 GDR |
47 | static tree wrap_cleanups_r (tree *, int *, void *); |
48 | static int complete_ptr_ref_or_void_ptr_p (tree, tree); | |
49 | static bool is_admissible_throw_operand (tree); | |
50 | static int can_convert_eh (tree, tree); | |
8d2733ca | 51 | |
52a11cbf | 52 | /* Sets up all the global eh stuff that needs to be initialized at the |
bbd0d54a | 53 | start of compilation. */ |
8d08fdba | 54 | |
8d08fdba | 55 | void |
5cc3d3b8 | 56 | init_exception_processing (void) |
8d08fdba | 57 | { |
52a11cbf RH |
58 | tree tmp; |
59 | ||
52a11cbf | 60 | /* void std::terminate (); */ |
1dbb6023 | 61 | push_namespace (std_identifier); |
0244e6f7 | 62 | tmp = build_function_type_list (void_type_node, NULL_TREE); |
52a11cbf | 63 | terminate_node = build_cp_library_fn_ptr ("terminate", tmp); |
9cd64686 | 64 | TREE_THIS_VOLATILE (terminate_node) = 1; |
0c11ada6 | 65 | TREE_NOTHROW (terminate_node) = 1; |
1dbb6023 | 66 | pop_namespace (); |
8ccc31eb | 67 | |
52a11cbf | 68 | /* void __cxa_call_unexpected(void *); */ |
0244e6f7 | 69 | tmp = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE); |
52a11cbf RH |
70 | call_unexpected_node |
71 | = push_throw_library_fn (get_identifier ("__cxa_call_unexpected"), tmp); | |
6874c264 JM |
72 | } |
73 | ||
e6855a2d | 74 | /* Returns an expression to be executed if an unhandled exception is |
aba649ba | 75 | propagated out of a cleanup region. */ |
e6855a2d | 76 | |
3b06d379 | 77 | tree |
5cc3d3b8 | 78 | cp_protect_cleanup_actions (void) |
e6855a2d MM |
79 | { |
80 | /* [except.terminate] | |
81 | ||
82 | When the destruction of an object during stack unwinding exits | |
83 | using an exception ... void terminate(); is called. */ | |
1d65f45c | 84 | return terminate_node; |
c8094d83 | 85 | } |
e6855a2d | 86 | |
6874c264 | 87 | static tree |
5cc3d3b8 | 88 | prepare_eh_type (tree type) |
8d08fdba | 89 | { |
52a11cbf RH |
90 | if (type == NULL_TREE) |
91 | return type; | |
f30432d7 MS |
92 | if (type == error_mark_node) |
93 | return error_mark_node; | |
8d2733ca | 94 | |
e92cc029 | 95 | /* peel back references, so they match. */ |
ee76b931 | 96 | type = non_reference (type); |
8d08fdba | 97 | |
e92cc029 | 98 | /* Peel off cv qualifiers. */ |
f30432d7 | 99 | type = TYPE_MAIN_VARIANT (type); |
8d2733ca | 100 | |
86ef5ebb JM |
101 | /* Functions and arrays decay to pointers. */ |
102 | type = type_decays_to (type); | |
103 | ||
52a11cbf | 104 | return type; |
8d08fdba | 105 | } |
8d08fdba | 106 | |
6cad4e17 JH |
107 | /* Return the type info for TYPE as used by EH machinery. */ |
108 | tree | |
109 | eh_type_info (tree type) | |
5816cb14 | 110 | { |
5816cb14 | 111 | tree exp; |
5816cb14 | 112 | |
93ca4ba7 JM |
113 | if (type == NULL_TREE || type == error_mark_node) |
114 | return type; | |
5816cb14 | 115 | |
52a11cbf RH |
116 | if (decl_is_java_type (type, 0)) |
117 | exp = build_java_class_ref (TREE_TYPE (type)); | |
118 | else | |
119 | exp = get_tinfo_decl (type); | |
5816cb14 | 120 | |
52a11cbf | 121 | return exp; |
5816cb14 AM |
122 | } |
123 | ||
6cad4e17 JH |
124 | /* Build the address of a typeinfo decl for use in the runtime |
125 | matching field of the exception model. */ | |
126 | ||
f9417da1 | 127 | tree |
6cad4e17 JH |
128 | build_eh_type_type (tree type) |
129 | { | |
130 | tree exp = eh_type_info (type); | |
131 | ||
132 | if (!exp) | |
133 | return NULL; | |
134 | ||
f820b0cf JH |
135 | mark_used (exp); |
136 | ||
6de9cd9a | 137 | return convert (ptr_type_node, build_address (exp)); |
6cad4e17 JH |
138 | } |
139 | ||
52a11cbf | 140 | tree |
5cc3d3b8 | 141 | build_exc_ptr (void) |
52a11cbf | 142 | { |
e79983f4 | 143 | return build_call_n (builtin_decl_explicit (BUILT_IN_EH_POINTER), |
1d65f45c | 144 | 1, integer_zero_node); |
52a11cbf RH |
145 | } |
146 | ||
448083e5 PC |
147 | /* Declare a function NAME, returning RETURN_TYPE, taking a single |
148 | parameter PARM_TYPE, with an empty exception specification. | |
149 | ||
150 | Note that the C++ ABI document does not have a throw-specifier on | |
151 | the routines declared below via this function. The declarations | |
152 | are consistent with the actual implementations in libsupc++. */ | |
153 | ||
154 | static tree | |
155 | declare_nothrow_library_fn (tree name, tree return_type, tree parm_type) | |
156 | { | |
0244e6f7 NF |
157 | return push_library_fn (name, build_function_type_list (return_type, |
158 | parm_type, | |
159 | NULL_TREE), | |
448083e5 PC |
160 | empty_except_spec); |
161 | } | |
162 | ||
39609077 RH |
163 | /* Build up a call to __cxa_get_exception_ptr so that we can build a |
164 | copy constructor for the thrown object. */ | |
165 | ||
166 | static tree | |
167 | do_get_exception_ptr (void) | |
168 | { | |
169 | tree fn; | |
170 | ||
171 | fn = get_identifier ("__cxa_get_exception_ptr"); | |
172 | if (!get_global_value_if_present (fn, &fn)) | |
173 | { | |
448083e5 PC |
174 | /* Declare void* __cxa_get_exception_ptr (void *) throw(). */ |
175 | fn = declare_nothrow_library_fn (fn, ptr_type_node, ptr_type_node); | |
0a35513e AH |
176 | |
177 | if (flag_tm) | |
178 | apply_tm_attr (fn, get_identifier ("transaction_pure")); | |
39609077 RH |
179 | } |
180 | ||
450f4293 NF |
181 | return cp_build_function_call_nary (fn, tf_warning_or_error, |
182 | build_exc_ptr (), NULL_TREE); | |
39609077 RH |
183 | } |
184 | ||
52a11cbf RH |
185 | /* Build up a call to __cxa_begin_catch, to tell the runtime that the |
186 | exception has been handled. */ | |
93ca4ba7 | 187 | |
52a11cbf | 188 | static tree |
5cc3d3b8 | 189 | do_begin_catch (void) |
9c606f69 | 190 | { |
52a11cbf RH |
191 | tree fn; |
192 | ||
193 | fn = get_identifier ("__cxa_begin_catch"); | |
c003e212 | 194 | if (!get_global_value_if_present (fn, &fn)) |
9c606f69 | 195 | { |
448083e5 PC |
196 | /* Declare void* __cxa_begin_catch (void *) throw(). */ |
197 | fn = declare_nothrow_library_fn (fn, ptr_type_node, ptr_type_node); | |
0a35513e AH |
198 | |
199 | /* Create its transactional-memory equivalent. */ | |
200 | if (flag_tm) | |
201 | { | |
202 | tree fn2 = get_identifier ("_ITM_cxa_begin_catch"); | |
203 | if (!get_global_value_if_present (fn2, &fn2)) | |
204 | fn2 = declare_nothrow_library_fn (fn2, ptr_type_node, | |
205 | ptr_type_node); | |
206 | apply_tm_attr (fn2, get_identifier ("transaction_pure")); | |
207 | record_tm_replacement (fn, fn2); | |
208 | } | |
9c606f69 | 209 | } |
52a11cbf | 210 | |
450f4293 NF |
211 | return cp_build_function_call_nary (fn, tf_warning_or_error, |
212 | build_exc_ptr (), NULL_TREE); | |
9c606f69 AM |
213 | } |
214 | ||
93ca4ba7 JM |
215 | /* Returns nonzero if cleaning up an exception of type TYPE (which can be |
216 | NULL_TREE for a ... handler) will not throw an exception. */ | |
217 | ||
218 | static int | |
5cc3d3b8 | 219 | dtor_nothrow (tree type) |
93ca4ba7 | 220 | { |
9bb1a81b | 221 | if (type == NULL_TREE || type == error_mark_node) |
93ca4ba7 JM |
222 | return 0; |
223 | ||
9bb1a81b | 224 | if (TYPE_HAS_TRIVIAL_DESTRUCTOR (type)) |
93ca4ba7 JM |
225 | return 1; |
226 | ||
9f4faeae MM |
227 | if (CLASSTYPE_LAZY_DESTRUCTOR (type)) |
228 | lazily_declare_fn (sfk_destructor, type); | |
229 | ||
50ad9642 | 230 | return TREE_NOTHROW (CLASSTYPE_DESTRUCTORS (type)); |
93ca4ba7 JM |
231 | } |
232 | ||
52a11cbf | 233 | /* Build up a call to __cxa_end_catch, to destroy the exception object |
93ca4ba7 | 234 | for the current catch block if no others are currently using it. */ |
6467930b | 235 | |
c7ae64f2 | 236 | static tree |
5cc3d3b8 | 237 | do_end_catch (tree type) |
72b7eeff | 238 | { |
6874c264 | 239 | tree fn, cleanup; |
52a11cbf RH |
240 | |
241 | fn = get_identifier ("__cxa_end_catch"); | |
c003e212 | 242 | if (!get_global_value_if_present (fn, &fn)) |
6874c264 | 243 | { |
52a11cbf RH |
244 | /* Declare void __cxa_end_catch (). */ |
245 | fn = push_void_library_fn (fn, void_list_node); | |
0c11ada6 JM |
246 | /* This can throw if the destructor for the exception throws. */ |
247 | TREE_NOTHROW (fn) = 0; | |
0a35513e AH |
248 | |
249 | /* Create its transactional-memory equivalent. */ | |
250 | if (flag_tm) | |
251 | { | |
252 | tree fn2 = get_identifier ("_ITM_cxa_end_catch"); | |
253 | if (!get_global_value_if_present (fn2, &fn2)) | |
254 | { | |
255 | fn2 = push_void_library_fn (fn2, void_list_node); | |
256 | TREE_NOTHROW (fn2) = 0; | |
257 | } | |
258 | apply_tm_attr (fn2, get_identifier ("transaction_pure")); | |
259 | record_tm_replacement (fn, fn2); | |
260 | } | |
6874c264 | 261 | } |
72b7eeff | 262 | |
450f4293 | 263 | cleanup = cp_build_function_call_vec (fn, NULL, tf_warning_or_error); |
93ca4ba7 | 264 | TREE_NOTHROW (cleanup) = dtor_nothrow (type); |
52a11cbf | 265 | |
c0700ea5 | 266 | return cleanup; |
c7ae64f2 JM |
267 | } |
268 | ||
269 | /* This routine creates the cleanup for the current exception. */ | |
72b7eeff | 270 | |
c7ae64f2 | 271 | static void |
5cc3d3b8 | 272 | push_eh_cleanup (tree type) |
c7ae64f2 | 273 | { |
52a11cbf | 274 | finish_decl_cleanup (NULL_TREE, do_end_catch (type)); |
f4a23343 JM |
275 | } |
276 | ||
e97f22c9 TT |
277 | /* Return nonzero value if DECL is a Java type suitable for catch or |
278 | throw. */ | |
279 | ||
52a11cbf | 280 | static bool |
5cc3d3b8 | 281 | decl_is_java_type (tree decl, int err) |
e97f22c9 | 282 | { |
52a11cbf RH |
283 | bool r = (TREE_CODE (decl) == POINTER_TYPE |
284 | && TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE | |
285 | && TYPE_FOR_JAVA (TREE_TYPE (decl))); | |
e97f22c9 TT |
286 | |
287 | if (err) | |
288 | { | |
289 | if (TREE_CODE (decl) == REFERENCE_TYPE | |
290 | && TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE | |
291 | && TYPE_FOR_JAVA (TREE_TYPE (decl))) | |
292 | { | |
293 | /* Can't throw a reference. */ | |
15a7ee29 | 294 | error ("type %qT is disallowed in Java %<throw%> or %<catch%>", |
0cbd7506 | 295 | decl); |
e97f22c9 TT |
296 | } |
297 | ||
298 | if (r) | |
299 | { | |
300 | tree jthrow_node | |
301 | = IDENTIFIER_GLOBAL_VALUE (get_identifier ("jthrowable")); | |
400500c4 | 302 | |
e97f22c9 | 303 | if (jthrow_node == NULL_TREE) |
400500c4 | 304 | fatal_error |
15a7ee29 | 305 | ("call to Java %<catch%> or %<throw%> with %<jthrowable%> undefined"); |
400500c4 | 306 | |
e97f22c9 TT |
307 | jthrow_node = TREE_TYPE (TREE_TYPE (jthrow_node)); |
308 | ||
309 | if (! DERIVED_FROM_P (jthrow_node, TREE_TYPE (decl))) | |
310 | { | |
311 | /* Thrown object must be a Throwable. */ | |
15a7ee29 | 312 | error ("type %qT is not derived from %<java::lang::Throwable%>", |
0cbd7506 | 313 | TREE_TYPE (decl)); |
e97f22c9 TT |
314 | } |
315 | } | |
316 | } | |
317 | ||
318 | return r; | |
319 | } | |
320 | ||
1f730ff7 ZW |
321 | /* Select the personality routine to be used for exception handling, |
322 | or issue an error if we need two different ones in the same | |
323 | translation unit. | |
bde8a146 RH |
324 | ??? At present DECL_FUNCTION_PERSONALITY is set via |
325 | LANG_HOOKS_EH_PERSONALITY. Should it be done here instead? */ | |
1f730ff7 | 326 | void |
5cc3d3b8 | 327 | choose_personality_routine (enum languages lang) |
52a11cbf RH |
328 | { |
329 | static enum { | |
330 | chose_none, | |
331 | chose_cpp, | |
332 | chose_java, | |
333 | gave_error | |
334 | } state; | |
335 | ||
336 | switch (state) | |
337 | { | |
1f730ff7 ZW |
338 | case gave_error: |
339 | return; | |
52a11cbf RH |
340 | |
341 | case chose_cpp: | |
1f730ff7 ZW |
342 | if (lang != lang_cplusplus) |
343 | goto give_error; | |
344 | return; | |
345 | ||
52a11cbf | 346 | case chose_java: |
1f730ff7 ZW |
347 | if (lang != lang_java) |
348 | goto give_error; | |
349 | return; | |
350 | ||
351 | case chose_none: | |
f4f206f4 | 352 | ; /* Proceed to language selection. */ |
1f730ff7 ZW |
353 | } |
354 | ||
355 | switch (lang) | |
356 | { | |
357 | case lang_cplusplus: | |
358 | state = chose_cpp; | |
52a11cbf RH |
359 | break; |
360 | ||
1f730ff7 ZW |
361 | case lang_java: |
362 | state = chose_java; | |
e79983f4 | 363 | terminate_node = builtin_decl_explicit (BUILT_IN_ABORT); |
f9417da1 | 364 | pragma_java_exceptions = true; |
52a11cbf | 365 | break; |
1f730ff7 ZW |
366 | |
367 | default: | |
8dc2b103 | 368 | gcc_unreachable (); |
52a11cbf | 369 | } |
1f730ff7 ZW |
370 | return; |
371 | ||
372 | give_error: | |
373 | error ("mixing C++ and Java catches in a single translation unit"); | |
374 | state = gave_error; | |
52a11cbf RH |
375 | } |
376 | ||
b35d4555 | 377 | /* Initialize the catch parameter DECL. */ |
6467930b | 378 | |
c8094d83 | 379 | static void |
5cc3d3b8 | 380 | initialize_handler_parm (tree decl, tree exp) |
8d08fdba | 381 | { |
b35d4555 MM |
382 | tree init; |
383 | tree init_type; | |
384 | ||
385 | /* Make sure we mark the catch param as used, otherwise we'll get a | |
386 | warning about an unused ((anonymous)). */ | |
387 | TREE_USED (decl) = 1; | |
03a904b5 | 388 | DECL_READ_P (decl) = 1; |
b35d4555 | 389 | |
52a11cbf | 390 | /* Figure out the type that the initializer is. Pointers are returned |
c8094d83 | 391 | adjusted by value from __cxa_begin_catch. Others are returned by |
52a11cbf | 392 | reference. */ |
b35d4555 | 393 | init_type = TREE_TYPE (decl); |
db24eb1f | 394 | if (!POINTER_TYPE_P (init_type)) |
b35d4555 MM |
395 | init_type = build_reference_type (init_type); |
396 | ||
1f730ff7 ZW |
397 | choose_personality_routine (decl_is_java_type (init_type, 0) |
398 | ? lang_java : lang_cplusplus); | |
b35d4555 MM |
399 | |
400 | /* Since pointers are passed by value, initialize a reference to | |
52a11cbf | 401 | pointer catch parm with the address of the temporary. */ |
c93586fa RS |
402 | if (TREE_CODE (init_type) == REFERENCE_TYPE |
403 | && TYPE_PTR_P (TREE_TYPE (init_type))) | |
93c0e0bb | 404 | exp = cp_build_addr_expr (exp, tf_warning_or_error); |
b35d4555 | 405 | |
52a11cbf | 406 | exp = ocp_convert (init_type, exp, CONV_IMPLICIT|CONV_FORCE_TEMP, 0); |
b35d4555 MM |
407 | |
408 | init = convert_from_reference (exp); | |
409 | ||
410 | /* If the constructor for the catch parm exits via an exception, we | |
411 | must call terminate. See eh23.C. */ | |
412 | if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl))) | |
faf5394a | 413 | { |
b35d4555 MM |
414 | /* Generate the copy constructor call directly so we can wrap it. |
415 | See also expand_default_init. */ | |
416 | init = ocp_convert (TREE_TYPE (decl), init, | |
417 | CONV_IMPLICIT|CONV_FORCE_TEMP, 0); | |
ba6c89a9 JM |
418 | /* Force cleanups now to avoid nesting problems with the |
419 | MUST_NOT_THROW_EXPR. */ | |
c1bb7f86 | 420 | init = fold_build_cleanup_point_expr (TREE_TYPE (init), init); |
52a11cbf | 421 | init = build1 (MUST_NOT_THROW_EXPR, TREE_TYPE (init), init); |
faf5394a MS |
422 | } |
423 | ||
b35d4555 | 424 | decl = pushdecl (decl); |
8d2733ca | 425 | |
e92fb501 | 426 | start_decl_1 (decl, true); |
d174af6c | 427 | cp_finish_decl (decl, init, /*init_const_expr_p=*/false, NULL_TREE, |
b35d4555 | 428 | LOOKUP_ONLYCONVERTING|DIRECT_BIND); |
5816cb14 AM |
429 | } |
430 | ||
3b06d379 SB |
431 | \f |
432 | /* Routine to see if exception handling is turned on. | |
433 | DO_WARN is nonzero if we want to inform the user that exception | |
434 | handling is turned off. | |
435 | ||
436 | This is used to ensure that -fexceptions has been specified if the | |
437 | compiler tries to use any exception-specific functions. */ | |
438 | ||
439 | static inline int | |
440 | doing_eh (void) | |
441 | { | |
442 | if (! flag_exceptions) | |
443 | { | |
444 | static int warned = 0; | |
445 | if (! warned) | |
446 | { | |
447 | error ("exception handling disabled, use -fexceptions to enable"); | |
448 | warned = 1; | |
449 | } | |
450 | return 0; | |
451 | } | |
452 | return 1; | |
453 | } | |
454 | ||
b35d4555 | 455 | /* Call this to start a catch block. DECL is the catch parameter. */ |
5816cb14 | 456 | |
b35d4555 | 457 | tree |
5cc3d3b8 | 458 | expand_start_catch_block (tree decl) |
5816cb14 | 459 | { |
39609077 | 460 | tree exp; |
4227d4a1 | 461 | tree type, init; |
5816cb14 | 462 | |
3b06d379 | 463 | if (! doing_eh ()) |
b35d4555 | 464 | return NULL_TREE; |
5816cb14 | 465 | |
b35d4555 | 466 | /* Make sure this declaration is reasonable. */ |
3c5c0849 | 467 | if (decl && !complete_ptr_ref_or_void_ptr_p (TREE_TYPE (decl), NULL_TREE)) |
2a50edcd | 468 | decl = error_mark_node; |
5816cb14 | 469 | |
52a11cbf RH |
470 | if (decl) |
471 | type = prepare_eh_type (TREE_TYPE (decl)); | |
472 | else | |
473 | type = NULL_TREE; | |
52a11cbf | 474 | |
39609077 | 475 | if (decl && decl_is_java_type (type, 1)) |
e97f22c9 | 476 | { |
39609077 RH |
477 | /* Java only passes object via pointer and doesn't require |
478 | adjusting. The java object is immediately before the | |
479 | generic exception header. */ | |
480 | exp = build_exc_ptr (); | |
481 | exp = build1 (NOP_EXPR, build_pointer_type (type), exp); | |
5d49b6a7 | 482 | exp = fold_build_pointer_plus (exp, |
db3927fb | 483 | fold_build1_loc (input_location, |
5d49b6a7 RG |
484 | NEGATE_EXPR, sizetype, |
485 | TYPE_SIZE_UNIT (TREE_TYPE (exp)))); | |
dd865ef6 | 486 | exp = cp_build_indirect_ref (exp, RO_NULL, tf_warning_or_error); |
39609077 RH |
487 | initialize_handler_parm (decl, exp); |
488 | return type; | |
489 | } | |
5816cb14 | 490 | |
39609077 RH |
491 | /* Call __cxa_end_catch at the end of processing the exception. */ |
492 | push_eh_cleanup (type); | |
493 | ||
4227d4a1 PC |
494 | init = do_begin_catch (); |
495 | ||
39609077 RH |
496 | /* If there's no decl at all, then all we need to do is make sure |
497 | to tell the runtime that we've begun handling the exception. */ | |
4227d4a1 PC |
498 | if (decl == NULL || decl == error_mark_node || init == error_mark_node) |
499 | finish_expr_stmt (init); | |
39609077 RH |
500 | |
501 | /* If the C++ object needs constructing, we need to do that before | |
502 | calling __cxa_begin_catch, so that std::uncaught_exception gets | |
503 | the right value during the copy constructor. */ | |
3db45ab5 | 504 | else if (flag_use_cxa_get_exception_ptr |
c7b5e395 | 505 | && TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (decl))) |
39609077 RH |
506 | { |
507 | exp = do_get_exception_ptr (); | |
508 | initialize_handler_parm (decl, exp); | |
4227d4a1 | 509 | finish_expr_stmt (init); |
39609077 RH |
510 | } |
511 | ||
512 | /* Otherwise the type uses a bitwise copy, and we don't have to worry | |
513 | about the value of std::uncaught_exception and therefore can do the | |
514 | copy with the return value of __cxa_end_catch instead. */ | |
515 | else | |
516 | { | |
2de9107a R |
517 | tree init_type = type; |
518 | ||
519 | /* Pointers are passed by values, everything else by reference. */ | |
520 | if (!TYPE_PTR_P (type)) | |
521 | init_type = build_pointer_type (type); | |
522 | if (init_type != TREE_TYPE (init)) | |
523 | init = build1 (NOP_EXPR, init_type, init); | |
524 | exp = create_temporary_var (init_type); | |
52a11cbf | 525 | DECL_REGISTER (exp) = 1; |
3db45ab5 | 526 | cp_finish_decl (exp, init, /*init_const_expr=*/false, |
d174af6c | 527 | NULL_TREE, LOOKUP_ONLYCONVERTING); |
39609077 | 528 | initialize_handler_parm (decl, exp); |
e97f22c9 | 529 | } |
5816cb14 | 530 | |
1a6025b4 | 531 | return type; |
5816cb14 AM |
532 | } |
533 | ||
f30432d7 | 534 | |
8d2733ca MS |
535 | /* Call this to end a catch block. Its responsible for emitting the |
536 | code to handle jumping back to the correct place, and for emitting | |
537 | the label to jump to if this catch block didn't match. */ | |
6467930b | 538 | |
824b9a4c | 539 | void |
5cc3d3b8 | 540 | expand_end_catch_block (void) |
8d08fdba | 541 | { |
3b06d379 | 542 | if (! doing_eh ()) |
f30432d7 | 543 | return; |
8d2733ca | 544 | |
0dde4175 JM |
545 | /* The exception being handled is rethrown if control reaches the end of |
546 | a handler of the function-try-block of a constructor or destructor. */ | |
547 | if (in_function_try_handler | |
548 | && (DECL_CONSTRUCTOR_P (current_function_decl) | |
549 | || DECL_DESTRUCTOR_P (current_function_decl))) | |
b35d4555 | 550 | finish_expr_stmt (build_throw (NULL_TREE)); |
8d2733ca | 551 | } |
8d08fdba | 552 | |
b35d4555 | 553 | tree |
5cc3d3b8 | 554 | begin_eh_spec_block (void) |
f30432d7 | 555 | { |
9feb3d6a | 556 | tree r; |
e70e0b60 SP |
557 | location_t spec_location = DECL_SOURCE_LOCATION (current_function_decl); |
558 | ||
9feb3d6a JM |
559 | /* A noexcept specification (or throw() with -fnothrow-opt) is a |
560 | MUST_NOT_THROW_EXPR. */ | |
561 | if (TYPE_NOEXCEPT_P (TREE_TYPE (current_function_decl))) | |
562 | { | |
e70e0b60 | 563 | r = build_stmt (spec_location, MUST_NOT_THROW_EXPR, NULL_TREE); |
9feb3d6a JM |
564 | TREE_SIDE_EFFECTS (r) = 1; |
565 | } | |
566 | else | |
e70e0b60 | 567 | r = build_stmt (spec_location, EH_SPEC_BLOCK, NULL_TREE, NULL_TREE); |
52a11cbf | 568 | add_stmt (r); |
9feb3d6a | 569 | TREE_OPERAND (r, 0) = push_stmt_list (); |
52a11cbf | 570 | return r; |
f30432d7 MS |
571 | } |
572 | ||
b35d4555 | 573 | void |
5cc3d3b8 | 574 | finish_eh_spec_block (tree raw_raises, tree eh_spec_block) |
f30432d7 | 575 | { |
52a11cbf | 576 | tree raises; |
0c11ada6 | 577 | |
9feb3d6a JM |
578 | TREE_OPERAND (eh_spec_block, 0) |
579 | = pop_stmt_list (TREE_OPERAND (eh_spec_block, 0)); | |
580 | ||
581 | if (TREE_CODE (eh_spec_block) == MUST_NOT_THROW_EXPR) | |
582 | return; | |
6c20b7e9 | 583 | |
52a11cbf RH |
584 | /* Strip cv quals, etc, from the specification types. */ |
585 | for (raises = NULL_TREE; | |
586 | raw_raises && TREE_VALUE (raw_raises); | |
587 | raw_raises = TREE_CHAIN (raw_raises)) | |
6cad4e17 JH |
588 | { |
589 | tree type = prepare_eh_type (TREE_VALUE (raw_raises)); | |
590 | tree tinfo = eh_type_info (type); | |
591 | ||
592 | mark_used (tinfo); | |
593 | raises = tree_cons (NULL_TREE, type, raises); | |
594 | } | |
6c20b7e9 | 595 | |
52a11cbf | 596 | EH_SPEC_RAISES (eh_spec_block) = raises; |
f30432d7 MS |
597 | } |
598 | ||
52a11cbf | 599 | /* Return a pointer to a buffer for an exception object of type TYPE. */ |
6467930b | 600 | |
52a11cbf | 601 | static tree |
5cc3d3b8 | 602 | do_allocate_exception (tree type) |
8d08fdba | 603 | { |
52a11cbf | 604 | tree fn; |
eb448459 | 605 | |
52a11cbf | 606 | fn = get_identifier ("__cxa_allocate_exception"); |
c003e212 | 607 | if (!get_global_value_if_present (fn, &fn)) |
f30432d7 | 608 | { |
448083e5 PC |
609 | /* Declare void *__cxa_allocate_exception(size_t) throw(). */ |
610 | fn = declare_nothrow_library_fn (fn, ptr_type_node, size_type_node); | |
0a35513e AH |
611 | |
612 | if (flag_tm) | |
613 | { | |
614 | tree fn2 = get_identifier ("_ITM_cxa_allocate_exception"); | |
615 | if (!get_global_value_if_present (fn2, &fn2)) | |
616 | fn2 = declare_nothrow_library_fn (fn2, ptr_type_node, | |
617 | size_type_node); | |
618 | apply_tm_attr (fn2, get_identifier ("transaction_pure")); | |
619 | record_tm_replacement (fn, fn2); | |
620 | } | |
e00737d2 | 621 | } |
c8094d83 | 622 | |
450f4293 NF |
623 | return cp_build_function_call_nary (fn, tf_warning_or_error, |
624 | size_in_bytes (type), NULL_TREE); | |
8d08fdba MS |
625 | } |
626 | ||
2ac8a0f9 | 627 | /* Call __cxa_free_exception from a cleanup. This is never invoked |
6f30f1f1 | 628 | directly, but see the comment for stabilize_throw_expr. */ |
f4a23343 | 629 | |
c6160f8f | 630 | static tree |
5cc3d3b8 | 631 | do_free_exception (tree ptr) |
f4a23343 | 632 | { |
52a11cbf | 633 | tree fn; |
f4a23343 | 634 | |
52a11cbf | 635 | fn = get_identifier ("__cxa_free_exception"); |
c003e212 | 636 | if (!get_global_value_if_present (fn, &fn)) |
f4a23343 | 637 | { |
448083e5 PC |
638 | /* Declare void __cxa_free_exception (void *) throw(). */ |
639 | fn = declare_nothrow_library_fn (fn, void_type_node, ptr_type_node); | |
f4a23343 JM |
640 | } |
641 | ||
450f4293 | 642 | return cp_build_function_call_nary (fn, tf_warning_or_error, ptr, NULL_TREE); |
f4a23343 JM |
643 | } |
644 | ||
6f30f1f1 JM |
645 | /* Wrap all cleanups for TARGET_EXPRs in MUST_NOT_THROW_EXPR. |
646 | Called from build_throw via walk_tree_without_duplicates. */ | |
647 | ||
648 | static tree | |
5cc3d3b8 | 649 | wrap_cleanups_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, |
0cbd7506 | 650 | void *data ATTRIBUTE_UNUSED) |
6f30f1f1 JM |
651 | { |
652 | tree exp = *tp; | |
653 | tree cleanup; | |
654 | ||
655 | /* Don't walk into types. */ | |
656 | if (TYPE_P (exp)) | |
657 | { | |
658 | *walk_subtrees = 0; | |
659 | return NULL_TREE; | |
660 | } | |
661 | if (TREE_CODE (exp) != TARGET_EXPR) | |
662 | return NULL_TREE; | |
663 | ||
664 | cleanup = TARGET_EXPR_CLEANUP (exp); | |
665 | if (cleanup) | |
666 | { | |
4e8dca1c | 667 | cleanup = build1 (MUST_NOT_THROW_EXPR, void_type_node, cleanup); |
6f30f1f1 JM |
668 | TARGET_EXPR_CLEANUP (exp) = cleanup; |
669 | } | |
670 | ||
671 | /* Keep iterating. */ | |
672 | return NULL_TREE; | |
673 | } | |
674 | ||
52a11cbf | 675 | /* Build a throw expression. */ |
6467930b | 676 | |
52a11cbf | 677 | tree |
5cc3d3b8 | 678 | build_throw (tree exp) |
8d08fdba | 679 | { |
6874c264 | 680 | tree fn; |
8d08fdba | 681 | |
52a11cbf RH |
682 | if (exp == error_mark_node) |
683 | return exp; | |
684 | ||
685 | if (processing_template_decl) | |
aff5c451 | 686 | { |
07515729 JJ |
687 | if (cfun) |
688 | current_function_returns_abnormally = 1; | |
73808ca6 JM |
689 | exp = build_min (THROW_EXPR, void_type_node, exp); |
690 | SET_EXPR_LOCATION (exp, input_location); | |
691 | return exp; | |
aff5c451 | 692 | } |
52a11cbf RH |
693 | |
694 | if (exp == null_node) | |
d4ee4d25 | 695 | warning (0, "throwing NULL, which has integral, not pointer type"); |
c8094d83 | 696 | |
52a11cbf RH |
697 | if (exp != NULL_TREE) |
698 | { | |
699 | if (!is_admissible_throw_operand (exp)) | |
0cbd7506 | 700 | return error_mark_node; |
52a11cbf RH |
701 | } |
702 | ||
3b06d379 | 703 | if (! doing_eh ()) |
59ccf49d | 704 | return error_mark_node; |
8d08fdba | 705 | |
52a11cbf | 706 | if (exp && decl_is_java_type (TREE_TYPE (exp), 1)) |
e97f22c9 | 707 | { |
52a11cbf | 708 | tree fn = get_identifier ("_Jv_Throw"); |
c003e212 | 709 | if (!get_global_value_if_present (fn, &fn)) |
e97f22c9 | 710 | { |
52a11cbf | 711 | /* Declare void _Jv_Throw (void *). */ |
0244e6f7 NF |
712 | tree tmp; |
713 | tmp = build_function_type_list (ptr_type_node, | |
714 | ptr_type_node, NULL_TREE); | |
c00996a3 | 715 | fn = push_throw_library_fn (fn, tmp); |
e97f22c9 | 716 | } |
6961a592 | 717 | else if (really_overloaded_fn (fn)) |
e05de6f2 | 718 | { |
15a7ee29 | 719 | error ("%qD should never be overloaded", fn); |
e05de6f2 | 720 | return error_mark_node; |
6961a592 | 721 | } |
9f6a794d | 722 | fn = OVL_CURRENT (fn); |
450f4293 NF |
723 | exp = cp_build_function_call_nary (fn, tf_warning_or_error, |
724 | exp, NULL_TREE); | |
e97f22c9 TT |
725 | } |
726 | else if (exp) | |
8d2733ca | 727 | { |
faae18ab | 728 | tree throw_type; |
41990f96 | 729 | tree temp_type; |
52a11cbf | 730 | tree cleanup; |
52a11cbf RH |
731 | tree object, ptr; |
732 | tree tmp; | |
b33a0480 | 733 | tree allocate_expr; |
52a11cbf | 734 | |
fbac6f3c MM |
735 | /* The CLEANUP_TYPE is the internal type of a destructor. */ |
736 | if (!cleanup_type) | |
737 | { | |
0244e6f7 NF |
738 | tmp = build_function_type_list (void_type_node, |
739 | ptr_type_node, NULL_TREE); | |
fbac6f3c MM |
740 | cleanup_type = build_pointer_type (tmp); |
741 | } | |
c8094d83 | 742 | |
52a11cbf | 743 | fn = get_identifier ("__cxa_throw"); |
c003e212 | 744 | if (!get_global_value_if_present (fn, &fn)) |
52a11cbf | 745 | { |
52a11cbf RH |
746 | /* Declare void __cxa_throw (void*, void*, void (*)(void*)). */ |
747 | /* ??? Second argument is supposed to be "std::type_info*". */ | |
0244e6f7 NF |
748 | tmp = build_function_type_list (void_type_node, |
749 | ptr_type_node, ptr_type_node, | |
750 | cleanup_type, NULL_TREE); | |
52a11cbf | 751 | fn = push_throw_library_fn (fn, tmp); |
0a35513e AH |
752 | |
753 | if (flag_tm) | |
754 | { | |
755 | tree fn2 = get_identifier ("_ITM_cxa_throw"); | |
756 | if (!get_global_value_if_present (fn2, &fn2)) | |
757 | fn2 = push_throw_library_fn (fn2, tmp); | |
758 | apply_tm_attr (fn2, get_identifier ("transaction_pure")); | |
759 | record_tm_replacement (fn, fn2); | |
760 | } | |
52a11cbf | 761 | } |
c8094d83 | 762 | |
3db45ab5 MS |
763 | /* [except.throw] |
764 | ||
765 | A throw-expression initializes a temporary object, the type | |
41990f96 MM |
766 | of which is determined by removing any top-level |
767 | cv-qualifiers from the static type of the operand of throw | |
768 | and adjusting the type from "array of T" or "function return | |
769 | T" to "pointer to T" or "pointer to function returning T" | |
770 | respectively. */ | |
771 | temp_type = is_bitfield_expr_with_lowered_type (exp); | |
772 | if (!temp_type) | |
ccaff498 | 773 | temp_type = cv_unqualified (type_decays_to (TREE_TYPE (exp))); |
a3b49ccd | 774 | |
52a11cbf RH |
775 | /* OK, this is kind of wacky. The standard says that we call |
776 | terminate when the exception handling mechanism, after | |
777 | completing evaluation of the expression to be thrown but | |
778 | before the exception is caught (_except.throw_), calls a | |
779 | user function that exits via an uncaught exception. | |
780 | ||
781 | So we have to protect the actual initialization of the | |
782 | exception object with terminate(), but evaluate the | |
783 | expression first. Since there could be temps in the | |
784 | expression, we need to handle that, too. We also expand | |
785 | the call to __cxa_allocate_exception first (which doesn't | |
786 | matter, since it can't throw). */ | |
787 | ||
52a11cbf | 788 | /* Allocate the space for the exception. */ |
41990f96 | 789 | allocate_expr = do_allocate_exception (temp_type); |
6f30f1f1 JM |
790 | allocate_expr = get_target_expr (allocate_expr); |
791 | ptr = TARGET_EXPR_SLOT (allocate_expr); | |
b33a0480 JM |
792 | TARGET_EXPR_CLEANUP (allocate_expr) = do_free_exception (ptr); |
793 | CLEANUP_EH_ONLY (allocate_expr) = 1; | |
794 | ||
41990f96 | 795 | object = build_nop (build_pointer_type (temp_type), ptr); |
dd865ef6 | 796 | object = cp_build_indirect_ref (object, RO_NULL, tf_warning_or_error); |
faae18ab | 797 | |
6f30f1f1 | 798 | /* And initialize the exception object. */ |
41990f96 | 799 | if (CLASS_TYPE_P (temp_type)) |
6f30f1f1 | 800 | { |
8af2fec4 | 801 | int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING; |
c166b898 | 802 | VEC(tree,gc) *exp_vec; |
8af2fec4 RY |
803 | |
804 | /* Under C++0x [12.8/16 class.copy], a thrown lvalue is sometimes | |
805 | treated as an rvalue for the purposes of overload resolution | |
806 | to favor move constructors over copy constructors. */ | |
807 | if (/* Must be a local, automatic variable. */ | |
808 | TREE_CODE (exp) == VAR_DECL | |
809 | && DECL_CONTEXT (exp) == current_function_decl | |
810 | && ! TREE_STATIC (exp) | |
811 | /* The variable must not have the `volatile' qualifier. */ | |
812 | && !(cp_type_quals (TREE_TYPE (exp)) & TYPE_QUAL_VOLATILE)) | |
813 | flags = flags | LOOKUP_PREFER_RVALUE; | |
814 | ||
41990f96 | 815 | /* Call the copy constructor. */ |
c166b898 | 816 | exp_vec = make_tree_vector_single (exp); |
3db45ab5 | 817 | exp = (build_special_member_call |
c166b898 ILT |
818 | (object, complete_ctor_identifier, &exp_vec, |
819 | TREE_TYPE (object), flags, tf_warning_or_error)); | |
820 | release_tree_vector (exp_vec); | |
41990f96 MM |
821 | if (exp == error_mark_node) |
822 | { | |
823 | error (" in thrown expression"); | |
824 | return error_mark_node; | |
825 | } | |
6f30f1f1 | 826 | } |
41990f96 | 827 | else |
10d3a72a PC |
828 | { |
829 | tmp = decay_conversion (exp); | |
830 | if (tmp == error_mark_node) | |
831 | return error_mark_node; | |
832 | exp = build2 (INIT_EXPR, temp_type, object, tmp); | |
833 | } | |
f4a23343 | 834 | |
b33a0480 JM |
835 | /* Mark any cleanups from the initialization as MUST_NOT_THROW, since |
836 | they are run after the exception object is initialized. */ | |
837 | cp_walk_tree_without_duplicates (&exp, wrap_cleanups_r, 0); | |
6de9cd9a | 838 | |
6f30f1f1 | 839 | /* Prepend the allocation. */ |
f293ce4b | 840 | exp = build2 (COMPOUND_EXPR, TREE_TYPE (exp), allocate_expr, exp); |
b33a0480 JM |
841 | |
842 | /* Force all the cleanups to be evaluated here so that we don't have | |
843 | to do them during unwinding. */ | |
844 | exp = build1 (CLEANUP_POINT_EXPR, void_type_node, exp); | |
72b7eeff | 845 | |
52a11cbf | 846 | throw_type = build_eh_type_type (prepare_eh_type (TREE_TYPE (object))); |
f4a23343 | 847 | |
9f4faeae | 848 | if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (object))) |
52a11cbf RH |
849 | { |
850 | cleanup = lookup_fnfields (TYPE_BINFO (TREE_TYPE (object)), | |
851 | complete_dtor_identifier, 0); | |
50ad9642 | 852 | cleanup = BASELINK_FUNCTIONS (cleanup); |
52a11cbf | 853 | mark_used (cleanup); |
dffd7eb6 | 854 | cxx_mark_addressable (cleanup); |
52a11cbf RH |
855 | /* Pretend it's a normal function. */ |
856 | cleanup = build1 (ADDR_EXPR, cleanup_type, cleanup); | |
f30432d7 | 857 | } |
52a11cbf | 858 | else |
7d60be94 | 859 | cleanup = build_int_cst (cleanup_type, 0); |
c8094d83 | 860 | |
52a11cbf | 861 | /* ??? Indicate that this function call throws throw_type. */ |
450f4293 NF |
862 | tmp = cp_build_function_call_nary (fn, tf_warning_or_error, |
863 | ptr, throw_type, cleanup, NULL_TREE); | |
72b7eeff | 864 | |
6f30f1f1 | 865 | /* Tack on the initialization stuff. */ |
f293ce4b | 866 | exp = build2 (COMPOUND_EXPR, TREE_TYPE (tmp), exp, tmp); |
8d2733ca MS |
867 | } |
868 | else | |
a3b49ccd | 869 | { |
52a11cbf | 870 | /* Rethrow current exception. */ |
6874c264 | 871 | |
52a11cbf | 872 | tree fn = get_identifier ("__cxa_rethrow"); |
c003e212 | 873 | if (!get_global_value_if_present (fn, &fn)) |
52a11cbf RH |
874 | { |
875 | /* Declare void __cxa_rethrow (void). */ | |
876 | fn = push_throw_library_fn | |
0244e6f7 | 877 | (fn, build_function_type_list (void_type_node, NULL_TREE)); |
52a11cbf | 878 | } |
6874c264 | 879 | |
0a35513e AH |
880 | if (flag_tm) |
881 | apply_tm_attr (fn, get_identifier ("transaction_pure")); | |
882 | ||
6f30f1f1 | 883 | /* ??? Indicate that this function call allows exceptions of the type |
c8094d83 | 884 | of the enclosing catch block (if known). */ |
450f4293 | 885 | exp = cp_build_function_call_vec (fn, NULL, tf_warning_or_error); |
a3b49ccd | 886 | } |
8d2733ca | 887 | |
52a11cbf | 888 | exp = build1 (THROW_EXPR, void_type_node, exp); |
73808ca6 | 889 | SET_EXPR_LOCATION (exp, input_location); |
02020185 | 890 | |
52a11cbf | 891 | return exp; |
8d08fdba | 892 | } |
4cfbc546 NS |
893 | |
894 | /* Make sure TYPE is complete, pointer to complete, reference to | |
895 | complete, or pointer to cv void. Issue diagnostic on failure. | |
838dfd8a | 896 | Return the zero on failure and nonzero on success. FROM can be |
4cfbc546 NS |
897 | the expr or decl from whence TYPE came, if available. */ |
898 | ||
899 | static int | |
5cc3d3b8 | 900 | complete_ptr_ref_or_void_ptr_p (tree type, tree from) |
4cfbc546 NS |
901 | { |
902 | int is_ptr; | |
c8094d83 | 903 | |
4cfbc546 NS |
904 | /* Check complete. */ |
905 | type = complete_type_or_else (type, from); | |
906 | if (!type) | |
907 | return 0; | |
c8094d83 | 908 | |
4cfbc546 NS |
909 | /* Or a pointer or ref to one, or cv void *. */ |
910 | is_ptr = TREE_CODE (type) == POINTER_TYPE; | |
911 | if (is_ptr || TREE_CODE (type) == REFERENCE_TYPE) | |
912 | { | |
913 | tree core = TREE_TYPE (type); | |
c8094d83 | 914 | |
b72801e2 | 915 | if (is_ptr && VOID_TYPE_P (core)) |
0cbd7506 | 916 | /* OK */; |
4cfbc546 | 917 | else if (!complete_type_or_else (core, from)) |
0cbd7506 | 918 | return 0; |
4cfbc546 NS |
919 | } |
920 | return 1; | |
921 | } | |
922 | ||
d064d75a GDR |
923 | /* Return truth-value if EXPRESSION is admissible in throw-expression, |
924 | i.e. if it is not of incomplete type or a pointer/reference to such | |
925 | a type or of an abstract class type. */ | |
926 | ||
927 | static bool | |
5cc3d3b8 | 928 | is_admissible_throw_operand (tree expr) |
d064d75a GDR |
929 | { |
930 | tree type = TREE_TYPE (expr); | |
931 | ||
932 | /* 15.1/4 [...] The type of the throw-expression shall not be an | |
0cbd7506 MS |
933 | incomplete type, or a pointer or a reference to an incomplete |
934 | type, other than void*, const void*, volatile void*, or | |
935 | const volatile void*. Except for these restriction and the | |
936 | restrictions on type matching mentioned in 15.3, the operand | |
937 | of throw is treated exactly as a function argument in a call | |
938 | (5.2.2) or the operand of a return statement. */ | |
d064d75a GDR |
939 | if (!complete_ptr_ref_or_void_ptr_p (type, expr)) |
940 | return false; | |
941 | ||
942 | /* 10.4/3 An abstract class shall not be used as a parameter type, | |
0cbd7506 MS |
943 | as a function return type or as type of an explicit |
944 | conversion. */ | |
d064d75a GDR |
945 | else if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type)) |
946 | { | |
15a7ee29 | 947 | error ("expression %qE of abstract class type %qT cannot " |
0cbd7506 | 948 | "be used in throw-expression", expr, type); |
d064d75a GDR |
949 | return false; |
950 | } | |
951 | ||
952 | return true; | |
953 | } | |
954 | ||
1660cb3a JM |
955 | /* Returns nonzero if FN is a declaration of a standard C library |
956 | function which is known not to throw. | |
957 | ||
958 | [lib.res.on.exception.handling]: None of the functions from the | |
959 | Standard C library shall report an error by throwing an | |
960 | exception, unless it calls a program-supplied function that | |
961 | throws an exception. */ | |
962 | ||
963 | #include "cfns.h" | |
964 | ||
965 | int | |
58f9752a | 966 | nothrow_libfn_p (const_tree fn) |
1660cb3a JM |
967 | { |
968 | tree id; | |
969 | ||
970 | if (TREE_PUBLIC (fn) | |
971 | && DECL_EXTERNAL (fn) | |
92643fea | 972 | && DECL_NAMESPACE_SCOPE_P (fn) |
eb68cb58 | 973 | && DECL_EXTERN_C_P (fn)) |
1660cb3a JM |
974 | /* OK */; |
975 | else | |
976 | /* Can't be a C library function. */ | |
977 | return 0; | |
978 | ||
84b8b0e0 ZW |
979 | /* Being a C library function, DECL_ASSEMBLER_NAME == DECL_NAME |
980 | unless the system headers are playing rename tricks, and if | |
981 | they are, we don't want to be confused by them. */ | |
982 | id = DECL_NAME (fn); | |
1660cb3a JM |
983 | return !!libc_name_p (IDENTIFIER_POINTER (id), IDENTIFIER_LENGTH (id)); |
984 | } | |
2bc9f1d1 JM |
985 | |
986 | /* Returns nonzero if an exception of type FROM will be caught by a | |
987 | handler for type TO, as per [except.handle]. */ | |
988 | ||
989 | static int | |
5cc3d3b8 | 990 | can_convert_eh (tree to, tree from) |
2bc9f1d1 | 991 | { |
ee76b931 MM |
992 | to = non_reference (to); |
993 | from = non_reference (from); | |
2bc9f1d1 JM |
994 | |
995 | if (TREE_CODE (to) == POINTER_TYPE && TREE_CODE (from) == POINTER_TYPE) | |
996 | { | |
997 | to = TREE_TYPE (to); | |
998 | from = TREE_TYPE (from); | |
999 | ||
1000 | if (! at_least_as_qualified_p (to, from)) | |
1001 | return 0; | |
1002 | ||
1003 | if (TREE_CODE (to) == VOID_TYPE) | |
1004 | return 1; | |
1005 | ||
f4f206f4 | 1006 | /* Else fall through. */ |
2bc9f1d1 JM |
1007 | } |
1008 | ||
2d46ec83 | 1009 | if (CLASS_TYPE_P (to) && CLASS_TYPE_P (from) |
2bc9f1d1 JM |
1010 | && PUBLICLY_UNIQUELY_DERIVED_P (to, from)) |
1011 | return 1; | |
1012 | ||
1013 | return 0; | |
1014 | } | |
1015 | ||
325c3691 RH |
1016 | /* Check whether any of the handlers in I are shadowed by another handler |
1017 | accepting TYPE. Note that the shadowing may not be complete; even if | |
1018 | an exception of type B would be caught by a handler for A, there could | |
1019 | be a derived class C for which A is an ambiguous base but B is not, so | |
1020 | the handler for B would catch an exception of type C. */ | |
2bc9f1d1 JM |
1021 | |
1022 | static void | |
325c3691 | 1023 | check_handlers_1 (tree master, tree_stmt_iterator i) |
2bc9f1d1 JM |
1024 | { |
1025 | tree type = TREE_TYPE (master); | |
2bc9f1d1 | 1026 | |
325c3691 RH |
1027 | for (; !tsi_end_p (i); tsi_next (&i)) |
1028 | { | |
1029 | tree handler = tsi_stmt (i); | |
1030 | if (TREE_TYPE (handler) && can_convert_eh (type, TREE_TYPE (handler))) | |
1031 | { | |
69bc6bff MLI |
1032 | warning_at (EXPR_LOCATION (handler), 0, |
1033 | "exception of type %qT will be caught", | |
1034 | TREE_TYPE (handler)); | |
1035 | warning_at (EXPR_LOCATION (master), 0, | |
1036 | " by earlier handler for %qT", type); | |
325c3691 | 1037 | break; |
0cbd7506 | 1038 | } |
325c3691 | 1039 | } |
2bc9f1d1 JM |
1040 | } |
1041 | ||
325c3691 | 1042 | /* Given a STATEMENT_LIST of HANDLERs, make sure that they're OK. */ |
2bc9f1d1 JM |
1043 | |
1044 | void | |
5cc3d3b8 | 1045 | check_handlers (tree handlers) |
2bc9f1d1 | 1046 | { |
325c3691 RH |
1047 | tree_stmt_iterator i; |
1048 | ||
1049 | /* If we don't have a STATEMENT_LIST, then we've just got one | |
1050 | handler, and thus nothing to warn about. */ | |
1051 | if (TREE_CODE (handlers) != STATEMENT_LIST) | |
1052 | return; | |
1053 | ||
1054 | i = tsi_start (handlers); | |
1055 | if (!tsi_end_p (i)) | |
1056 | while (1) | |
1057 | { | |
0cbd7506 | 1058 | tree handler = tsi_stmt (i); |
325c3691 RH |
1059 | tsi_next (&i); |
1060 | ||
1061 | /* No more handlers; nothing to shadow. */ | |
1062 | if (tsi_end_p (i)) | |
1063 | break; | |
1064 | if (TREE_TYPE (handler) == NULL_TREE) | |
69bc6bff MLI |
1065 | permerror (EXPR_LOCATION (handler), "%<...%>" |
1066 | " handler must be the last handler for its try block"); | |
325c3691 RH |
1067 | else |
1068 | check_handlers_1 (handler, i); | |
1069 | } | |
2bc9f1d1 | 1070 | } |
0a766368 JM |
1071 | |
1072 | /* walk_tree helper for finish_noexcept_expr. Returns non-null if the | |
1073 | expression *TP causes the noexcept operator to evaluate to false. | |
1074 | ||
1075 | 5.3.7 [expr.noexcept]: The result of the noexcept operator is false if | |
1076 | in a potentially-evaluated context the expression would contain | |
1077 | * a potentially evaluated call to a function, member function, | |
1078 | function pointer, or member function pointer that does not have a | |
1079 | non-throwing exception-specification (15.4), | |
1080 | * a potentially evaluated throw-expression (15.1), | |
1081 | * a potentially evaluated dynamic_cast expression dynamic_cast<T>(v), | |
1082 | where T is a reference type, that requires a run-time check (5.2.7), or | |
1083 | * a potentially evaluated typeid expression (5.2.8) applied to a glvalue | |
1084 | expression whose type is a polymorphic class type (10.3). */ | |
1085 | ||
1086 | static tree | |
1087 | check_noexcept_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, | |
1088 | void *data ATTRIBUTE_UNUSED) | |
1089 | { | |
1090 | tree t = *tp; | |
1091 | enum tree_code code = TREE_CODE (t); | |
1092 | if (code == CALL_EXPR | |
1093 | || code == AGGR_INIT_EXPR) | |
1094 | { | |
1095 | /* We can only use the exception specification of the called function | |
1096 | for determining the value of a noexcept expression; we can't use | |
1097 | TREE_NOTHROW, as it might have a different value in another | |
1098 | translation unit, creating ODR problems. | |
1099 | ||
1100 | We could use TREE_NOTHROW (t) for !TREE_PUBLIC fns, though... */ | |
1101 | tree fn = (code == AGGR_INIT_EXPR | |
1102 | ? AGGR_INIT_EXPR_FN (t) : CALL_EXPR_FN (t)); | |
59f9c2ed JM |
1103 | tree type = TREE_TYPE (TREE_TYPE (fn)); |
1104 | ||
1105 | STRIP_NOPS (fn); | |
0a766368 | 1106 | if (TREE_CODE (fn) == ADDR_EXPR) |
fa2200cb JM |
1107 | fn = TREE_OPERAND (fn, 0); |
1108 | if (TREE_CODE (fn) == FUNCTION_DECL) | |
0a766368 JM |
1109 | { |
1110 | /* We do use TREE_NOTHROW for ABI internals like __dynamic_cast, | |
1111 | and for C library functions known not to throw. */ | |
fa2200cb | 1112 | if (DECL_EXTERN_C_P (fn) |
59f9c2ed JM |
1113 | && (DECL_ARTIFICIAL (fn) |
1114 | || nothrow_libfn_p (fn))) | |
1115 | return TREE_NOTHROW (fn) ? NULL_TREE : fn; | |
fa2200cb JM |
1116 | /* A call to a constexpr function is noexcept if the call |
1117 | is a constant expression. */ | |
1118 | if (DECL_DECLARED_CONSTEXPR_P (fn) | |
1119 | && is_sub_constant_expr (t)) | |
1120 | return NULL_TREE; | |
0a766368 | 1121 | } |
59f9c2ed JM |
1122 | if (!TYPE_NOTHROW_P (type)) |
1123 | return fn; | |
0a766368 JM |
1124 | } |
1125 | ||
1126 | return NULL_TREE; | |
1127 | } | |
1128 | ||
2c5df20f JM |
1129 | /* If a function that causes a noexcept-expression to be false isn't |
1130 | defined yet, remember it and check it for TREE_NOTHROW again at EOF. */ | |
1131 | ||
1132 | typedef struct GTY(()) pending_noexcept { | |
1133 | tree fn; | |
1134 | location_t loc; | |
1135 | } pending_noexcept; | |
1136 | DEF_VEC_O(pending_noexcept); | |
1137 | DEF_VEC_ALLOC_O(pending_noexcept,gc); | |
1138 | static GTY(()) VEC(pending_noexcept,gc) *pending_noexcept_checks; | |
1139 | ||
1140 | /* FN is a FUNCTION_DECL that caused a noexcept-expr to be false. Warn if | |
1141 | it can't throw. */ | |
1142 | ||
1143 | static void | |
1144 | maybe_noexcept_warning (tree fn) | |
1145 | { | |
1146 | if (TREE_NOTHROW (fn)) | |
1147 | { | |
1148 | warning (OPT_Wnoexcept, "noexcept-expression evaluates to %<false%> " | |
1149 | "because of a call to %qD", fn); | |
1150 | warning (OPT_Wnoexcept, "but %q+D does not throw; perhaps " | |
1151 | "it should be declared %<noexcept%>", fn); | |
1152 | } | |
1153 | } | |
1154 | ||
1155 | /* Check any functions that weren't defined earlier when they caused a | |
1156 | noexcept expression to evaluate to false. */ | |
1157 | ||
1158 | void | |
1159 | perform_deferred_noexcept_checks (void) | |
1160 | { | |
1161 | int i; | |
1162 | pending_noexcept *p; | |
1163 | location_t saved_loc = input_location; | |
ac47786e | 1164 | FOR_EACH_VEC_ELT (pending_noexcept, pending_noexcept_checks, i, p) |
2c5df20f JM |
1165 | { |
1166 | input_location = p->loc; | |
1167 | maybe_noexcept_warning (p->fn); | |
1168 | } | |
1169 | input_location = saved_loc; | |
1170 | } | |
1171 | ||
0a766368 JM |
1172 | /* Evaluate noexcept ( EXPR ). */ |
1173 | ||
1174 | tree | |
59f9c2ed | 1175 | finish_noexcept_expr (tree expr, tsubst_flags_t complain) |
0a766368 | 1176 | { |
d0bb79ac JM |
1177 | if (expr == error_mark_node) |
1178 | return error_mark_node; | |
1179 | ||
0a766368 JM |
1180 | if (processing_template_decl) |
1181 | return build_min (NOEXCEPT_EXPR, boolean_type_node, expr); | |
1182 | ||
6eaade31 JM |
1183 | return (expr_noexcept_p (expr, complain) |
1184 | ? boolean_true_node : boolean_false_node); | |
1185 | } | |
1186 | ||
1187 | /* Returns whether EXPR is noexcept, possibly warning if allowed by | |
1188 | COMPLAIN. */ | |
1189 | ||
1190 | bool | |
1191 | expr_noexcept_p (tree expr, tsubst_flags_t complain) | |
1192 | { | |
1193 | tree fn; | |
1194 | ||
1195 | if (expr == error_mark_node) | |
1196 | return false; | |
1197 | ||
59f9c2ed JM |
1198 | fn = cp_walk_tree_without_duplicates (&expr, check_noexcept_r, 0); |
1199 | if (fn) | |
1200 | { | |
2c5df20f JM |
1201 | if ((complain & tf_warning) && warn_noexcept |
1202 | && TREE_CODE (fn) == FUNCTION_DECL) | |
59f9c2ed | 1203 | { |
2c5df20f JM |
1204 | if (!DECL_INITIAL (fn)) |
1205 | { | |
1206 | /* Not defined yet; check again at EOF. */ | |
1207 | pending_noexcept *p | |
1208 | = VEC_safe_push (pending_noexcept, gc, | |
1209 | pending_noexcept_checks, NULL); | |
1210 | p->fn = fn; | |
1211 | p->loc = input_location; | |
1212 | } | |
1213 | else | |
1214 | maybe_noexcept_warning (fn); | |
59f9c2ed | 1215 | } |
6eaade31 | 1216 | return false; |
59f9c2ed | 1217 | } |
0a766368 | 1218 | else |
6eaade31 | 1219 | return true; |
0a766368 | 1220 | } |
3a55fb4c JM |
1221 | |
1222 | /* Return true iff SPEC is throw() or noexcept(true). */ | |
1223 | ||
1224 | bool | |
1225 | nothrow_spec_p (const_tree spec) | |
1226 | { | |
10261728 | 1227 | gcc_assert (!DEFERRED_NOEXCEPT_SPEC_P (spec)); |
3a55fb4c JM |
1228 | if (spec == NULL_TREE |
1229 | || TREE_VALUE (spec) != NULL_TREE | |
1230 | || spec == noexcept_false_spec) | |
1231 | return false; | |
1232 | if (TREE_PURPOSE (spec) == NULL_TREE | |
1233 | || spec == noexcept_true_spec) | |
1234 | return true; | |
1235 | gcc_assert (processing_template_decl | |
1236 | || TREE_PURPOSE (spec) == error_mark_node); | |
1237 | return false; | |
1238 | } | |
1239 | ||
1240 | /* For FUNCTION_TYPE or METHOD_TYPE, true if NODE is noexcept. This is the | |
1241 | case for things declared noexcept(true) and, with -fnothrow-opt, for | |
1242 | throw() functions. */ | |
1243 | ||
1244 | bool | |
1245 | type_noexcept_p (const_tree type) | |
1246 | { | |
1247 | tree spec = TYPE_RAISES_EXCEPTIONS (type); | |
10261728 | 1248 | gcc_assert (!DEFERRED_NOEXCEPT_SPEC_P (spec)); |
3a55fb4c JM |
1249 | if (flag_nothrow_opt) |
1250 | return nothrow_spec_p (spec); | |
1251 | else | |
1252 | return spec == noexcept_true_spec; | |
1253 | } | |
1254 | ||
1255 | /* For FUNCTION_TYPE or METHOD_TYPE, true if NODE can throw any type, | |
1256 | i.e. no exception-specification or noexcept(false). */ | |
1257 | ||
1258 | bool | |
1259 | type_throw_all_p (const_tree type) | |
1260 | { | |
1261 | tree spec = TYPE_RAISES_EXCEPTIONS (type); | |
10261728 | 1262 | gcc_assert (!DEFERRED_NOEXCEPT_SPEC_P (spec)); |
3a55fb4c JM |
1263 | return spec == NULL_TREE || spec == noexcept_false_spec; |
1264 | } | |
1265 | ||
1266 | /* Create a representation of the noexcept-specification with | |
1267 | constant-expression of EXPR. COMPLAIN is as for tsubst. */ | |
1268 | ||
1269 | tree | |
1270 | build_noexcept_spec (tree expr, int complain) | |
1271 | { | |
fa2200cb JM |
1272 | /* This isn't part of the signature, so don't bother trying to evaluate |
1273 | it until instantiation. */ | |
10261728 | 1274 | if (!processing_template_decl && TREE_CODE (expr) != DEFERRED_NOEXCEPT) |
fa2200cb | 1275 | { |
fa2200cb JM |
1276 | expr = perform_implicit_conversion_flags (boolean_type_node, expr, |
1277 | complain, | |
1278 | LOOKUP_NORMAL); | |
0309d288 | 1279 | expr = cxx_constant_value (expr); |
fa2200cb | 1280 | } |
3a55fb4c JM |
1281 | if (expr == boolean_true_node) |
1282 | return noexcept_true_spec; | |
1283 | else if (expr == boolean_false_node) | |
1284 | return noexcept_false_spec; | |
d0bb79ac JM |
1285 | else if (expr == error_mark_node) |
1286 | return error_mark_node; | |
3a55fb4c JM |
1287 | else |
1288 | { | |
10261728 JM |
1289 | gcc_assert (processing_template_decl || expr == error_mark_node |
1290 | || TREE_CODE (expr) == DEFERRED_NOEXCEPT); | |
3a55fb4c JM |
1291 | return build_tree_list (expr, NULL_TREE); |
1292 | } | |
1293 | } | |
b6c917ff JM |
1294 | |
1295 | #include "gt-cp-except.h" |