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1 | /* Perform optimizations on tree structure. | |
2 | Copyright (C) 1998-2020 Free Software Foundation, Inc. | |
3 | Written by Mark Michell (mark@codesourcery.com). | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "target.h" | |
25 | #include "cp-tree.h" | |
26 | #include "stringpool.h" | |
27 | #include "cgraph.h" | |
28 | #include "debug.h" | |
29 | #include "tree-inline.h" | |
30 | #include "tree-iterator.h" | |
31 | ||
32 | /* Prototypes. */ | |
33 | ||
34 | static void update_cloned_parm (tree, tree, bool); | |
35 | ||
36 | /* CLONED_PARM is a copy of CLONE, generated for a cloned constructor | |
37 | or destructor. Update it to ensure that the source-position for | |
38 | the cloned parameter matches that for the original, and that the | |
39 | debugging generation code will be able to find the original PARM. */ | |
40 | ||
41 | static void | |
42 | update_cloned_parm (tree parm, tree cloned_parm, bool first) | |
43 | { | |
44 | DECL_ABSTRACT_ORIGIN (cloned_parm) = parm; | |
45 | ||
46 | /* We may have taken its address. */ | |
47 | TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm); | |
48 | ||
49 | DECL_BY_REFERENCE (cloned_parm) = DECL_BY_REFERENCE (parm); | |
50 | ||
51 | /* The definition might have different constness. */ | |
52 | TREE_READONLY (cloned_parm) = TREE_READONLY (parm); | |
53 | ||
54 | TREE_USED (cloned_parm) = !first || TREE_USED (parm); | |
55 | ||
56 | /* The name may have changed from the declaration. */ | |
57 | DECL_NAME (cloned_parm) = DECL_NAME (parm); | |
58 | DECL_SOURCE_LOCATION (cloned_parm) = DECL_SOURCE_LOCATION (parm); | |
59 | TREE_TYPE (cloned_parm) = TREE_TYPE (parm); | |
60 | ||
61 | DECL_GIMPLE_REG_P (cloned_parm) = DECL_GIMPLE_REG_P (parm); | |
62 | } | |
63 | ||
64 | /* Like copy_decl_no_change, but handle DECL_OMP_PRIVATIZED_MEMBER | |
65 | properly. */ | |
66 | ||
67 | static tree | |
68 | cxx_copy_decl (tree decl, copy_body_data *id) | |
69 | { | |
70 | tree copy = copy_decl_no_change (decl, id); | |
71 | if (VAR_P (decl) | |
72 | && DECL_HAS_VALUE_EXPR_P (decl) | |
73 | && DECL_ARTIFICIAL (decl) | |
74 | && DECL_LANG_SPECIFIC (decl) | |
75 | && DECL_OMP_PRIVATIZED_MEMBER (decl)) | |
76 | { | |
77 | tree expr = DECL_VALUE_EXPR (copy); | |
78 | walk_tree (&expr, copy_tree_body_r, id, NULL); | |
79 | SET_DECL_VALUE_EXPR (copy, expr); | |
80 | } | |
81 | return copy; | |
82 | } | |
83 | ||
84 | /* FN is a function in High GIMPLE form that has a complete body and no | |
85 | CFG. CLONE is a function whose body is to be set to a copy of FN, | |
86 | mapping argument declarations according to the ARG_MAP splay_tree. */ | |
87 | ||
88 | static void | |
89 | clone_body (tree clone, tree fn, void *arg_map) | |
90 | { | |
91 | copy_body_data id; | |
92 | tree stmts; | |
93 | ||
94 | /* Clone the body, as if we were making an inline call. But, remap | |
95 | the parameters in the callee to the parameters of caller. */ | |
96 | memset (&id, 0, sizeof (id)); | |
97 | id.src_fn = fn; | |
98 | id.dst_fn = clone; | |
99 | id.src_cfun = DECL_STRUCT_FUNCTION (fn); | |
100 | id.decl_map = static_cast<hash_map<tree, tree> *> (arg_map); | |
101 | ||
102 | id.copy_decl = cxx_copy_decl; | |
103 | id.transform_call_graph_edges = CB_CGE_DUPLICATE; | |
104 | id.transform_new_cfg = true; | |
105 | id.transform_return_to_modify = false; | |
106 | id.transform_lang_insert_block = NULL; | |
107 | ||
108 | /* We're not inside any EH region. */ | |
109 | id.eh_lp_nr = 0; | |
110 | ||
111 | stmts = DECL_SAVED_TREE (fn); | |
112 | walk_tree (&stmts, copy_tree_body_r, &id, NULL); | |
113 | ||
114 | /* Also remap the initializer of any static variables so that they (in | |
115 | particular, any label addresses) correspond to the base variant rather | |
116 | than the abstract one. */ | |
117 | if (DECL_NAME (clone) == base_dtor_identifier | |
118 | || DECL_NAME (clone) == base_ctor_identifier) | |
119 | { | |
120 | unsigned ix; | |
121 | tree decl; | |
122 | ||
123 | FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (fn), ix, decl) | |
124 | walk_tree (&DECL_INITIAL (decl), copy_tree_body_r, &id, NULL); | |
125 | } | |
126 | ||
127 | append_to_statement_list_force (stmts, &DECL_SAVED_TREE (clone)); | |
128 | } | |
129 | ||
130 | /* DELETE_DTOR is a delete destructor whose body will be built. | |
131 | COMPLETE_DTOR is the corresponding complete destructor. */ | |
132 | ||
133 | static void | |
134 | build_delete_destructor_body (tree delete_dtor, tree complete_dtor) | |
135 | { | |
136 | tree parm = DECL_ARGUMENTS (delete_dtor); | |
137 | tree virtual_size = cxx_sizeof (current_class_type); | |
138 | ||
139 | /* Call the delete function. */ | |
140 | tree call_delete = build_op_delete_call (DELETE_EXPR, current_class_ptr, | |
141 | virtual_size, | |
142 | /*global_p=*/false, | |
143 | /*placement=*/NULL_TREE, | |
144 | /*alloc_fn=*/NULL_TREE, | |
145 | tf_warning_or_error); | |
146 | ||
147 | tree op = get_callee_fndecl (call_delete); | |
148 | if (op && DECL_P (op) && destroying_delete_p (op)) | |
149 | { | |
150 | /* The destroying delete will handle calling complete_dtor. */ | |
151 | add_stmt (call_delete); | |
152 | } | |
153 | else | |
154 | { | |
155 | /* Call the corresponding complete destructor. */ | |
156 | gcc_assert (complete_dtor); | |
157 | tree call_dtor = build_cxx_call (complete_dtor, 1, &parm, | |
158 | tf_warning_or_error); | |
159 | ||
160 | /* Operator delete must be called, whether or not the dtor throws. */ | |
161 | add_stmt (build2 (TRY_FINALLY_EXPR, void_type_node, | |
162 | call_dtor, call_delete)); | |
163 | } | |
164 | ||
165 | /* Return the address of the object. | |
166 | ??? How is it useful to return an invalid address? */ | |
167 | if (targetm.cxx.cdtor_returns_this ()) | |
168 | { | |
169 | tree val = DECL_ARGUMENTS (delete_dtor); | |
170 | val = build2 (MODIFY_EXPR, TREE_TYPE (val), | |
171 | DECL_RESULT (delete_dtor), val); | |
172 | add_stmt (build_stmt (0, RETURN_EXPR, val)); | |
173 | } | |
174 | } | |
175 | ||
176 | /* Return name of comdat group for complete and base ctor (or dtor) | |
177 | that have the same body. If dtor is virtual, deleting dtor goes | |
178 | into this comdat group as well. */ | |
179 | ||
180 | static tree | |
181 | cdtor_comdat_group (tree complete, tree base) | |
182 | { | |
183 | tree complete_name = DECL_ASSEMBLER_NAME (complete); | |
184 | tree base_name = DECL_ASSEMBLER_NAME (base); | |
185 | char *grp_name; | |
186 | const char *p, *q; | |
187 | bool diff_seen = false; | |
188 | size_t idx; | |
189 | gcc_assert (IDENTIFIER_LENGTH (complete_name) | |
190 | == IDENTIFIER_LENGTH (base_name)); | |
191 | grp_name = XALLOCAVEC (char, IDENTIFIER_LENGTH (complete_name) + 1); | |
192 | p = IDENTIFIER_POINTER (complete_name); | |
193 | q = IDENTIFIER_POINTER (base_name); | |
194 | for (idx = 0; idx < IDENTIFIER_LENGTH (complete_name); idx++) | |
195 | if (p[idx] == q[idx]) | |
196 | grp_name[idx] = p[idx]; | |
197 | else | |
198 | { | |
199 | gcc_assert (!diff_seen | |
200 | && idx > 0 | |
201 | && (p[idx - 1] == 'C' || p[idx - 1] == 'D' | |
202 | || p[idx - 1] == 'I') | |
203 | && p[idx] == '1' | |
204 | && q[idx] == '2'); | |
205 | grp_name[idx] = '5'; | |
206 | diff_seen = true; | |
207 | } | |
208 | grp_name[idx] = '\0'; | |
209 | gcc_assert (diff_seen); | |
210 | return get_identifier (grp_name); | |
211 | } | |
212 | ||
213 | /* Returns true iff we can make the base and complete [cd]tor aliases of | |
214 | the same symbol rather than separate functions. */ | |
215 | ||
216 | static bool | |
217 | can_alias_cdtor (tree fn) | |
218 | { | |
219 | /* If aliases aren't supported by the assembler, fail. */ | |
220 | if (!TARGET_SUPPORTS_ALIASES) | |
221 | return false; | |
222 | ||
223 | /* We can't use an alias if there are virtual bases. */ | |
224 | if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn))) | |
225 | return false; | |
226 | gcc_assert (DECL_MAYBE_IN_CHARGE_CDTOR_P (fn)); | |
227 | /* Don't use aliases for weak/linkonce definitions unless we can put both | |
228 | symbols in the same COMDAT group. */ | |
229 | return (DECL_INTERFACE_KNOWN (fn) | |
230 | && (SUPPORTS_ONE_ONLY || !DECL_WEAK (fn)) | |
231 | && (!DECL_ONE_ONLY (fn) | |
232 | || (HAVE_COMDAT_GROUP && DECL_WEAK (fn)))); | |
233 | } | |
234 | ||
235 | /* FN is a [cd]tor, fns is a pointer to an array of length 3. Fill fns | |
236 | with pointers to the base, complete, and deleting variants. */ | |
237 | ||
238 | static void | |
239 | populate_clone_array (tree fn, tree *fns) | |
240 | { | |
241 | tree clone; | |
242 | ||
243 | fns[0] = NULL_TREE; | |
244 | fns[1] = NULL_TREE; | |
245 | fns[2] = NULL_TREE; | |
246 | ||
247 | tree ctx = DECL_CONTEXT (fn); | |
248 | ||
249 | FOR_EACH_CLONE (clone, fn) | |
250 | if (DECL_NAME (clone) == complete_dtor_identifier | |
251 | || DECL_NAME (clone) == complete_ctor_identifier) | |
252 | fns[1] = clone; | |
253 | else if (DECL_NAME (clone) == base_dtor_identifier | |
254 | || DECL_NAME (clone) == base_ctor_identifier) | |
255 | { | |
256 | /* We don't need to define the base variants for a final class. */ | |
257 | if (!CLASSTYPE_FINAL (ctx)) | |
258 | fns[0] = clone; | |
259 | } | |
260 | else if (DECL_NAME (clone) == deleting_dtor_identifier) | |
261 | fns[2] = clone; | |
262 | else | |
263 | gcc_unreachable (); | |
264 | } | |
265 | ||
266 | /* FN is a constructor or destructor, and there are FUNCTION_DECLs | |
267 | cloned from it nearby. Instead of cloning this body, leave it | |
268 | alone and create tiny one-call bodies for the cloned | |
269 | FUNCTION_DECLs. These clones are sibcall candidates, and their | |
270 | resulting code will be very thunk-esque. */ | |
271 | ||
272 | static bool | |
273 | maybe_thunk_body (tree fn, bool force) | |
274 | { | |
275 | tree bind, block, call, clone, clone_result, fn_parm, fn_parm_typelist; | |
276 | tree last_arg, modify, *args; | |
277 | int parmno, vtt_parmno, max_parms; | |
278 | tree fns[3]; | |
279 | ||
280 | if (!force && !flag_declone_ctor_dtor) | |
281 | return 0; | |
282 | ||
283 | /* If function accepts variable arguments, give up. */ | |
284 | last_arg = tree_last (TYPE_ARG_TYPES (TREE_TYPE (fn))); | |
285 | if (last_arg != void_list_node) | |
286 | return 0; | |
287 | ||
288 | /* If we got this far, we've decided to turn the clones into thunks. */ | |
289 | ||
290 | /* We're going to generate code for fn, so it is no longer "abstract." | |
291 | Also make the unified ctor/dtor private to either the translation unit | |
292 | (for non-vague linkage ctors) or the COMDAT group (otherwise). */ | |
293 | ||
294 | populate_clone_array (fn, fns); | |
295 | ||
296 | /* Can happen during error recovery (c++/71464). */ | |
297 | if (!fns[0] || !fns[1]) | |
298 | return 0; | |
299 | ||
300 | /* Don't use thunks if the base clone omits inherited parameters. */ | |
301 | if (ctor_omit_inherited_parms (fns[0])) | |
302 | return 0; | |
303 | ||
304 | DECL_ABSTRACT_P (fn) = false; | |
305 | if (!DECL_WEAK (fn)) | |
306 | { | |
307 | TREE_PUBLIC (fn) = false; | |
308 | DECL_EXTERNAL (fn) = false; | |
309 | DECL_INTERFACE_KNOWN (fn) = true; | |
310 | } | |
311 | else if (HAVE_COMDAT_GROUP) | |
312 | { | |
313 | /* At eof, defer creation of mangling aliases temporarily. */ | |
314 | bool save_defer_mangling_aliases = defer_mangling_aliases; | |
315 | defer_mangling_aliases = true; | |
316 | tree comdat_group = cdtor_comdat_group (fns[1], fns[0]); | |
317 | defer_mangling_aliases = save_defer_mangling_aliases; | |
318 | cgraph_node::get_create (fns[0])->set_comdat_group (comdat_group); | |
319 | cgraph_node::get_create (fns[1])->add_to_same_comdat_group | |
320 | (cgraph_node::get_create (fns[0])); | |
321 | symtab_node::get (fn)->add_to_same_comdat_group | |
322 | (symtab_node::get (fns[0])); | |
323 | if (fns[2]) | |
324 | /* If *[CD][12]* dtors go into the *[CD]5* comdat group and dtor is | |
325 | virtual, it goes into the same comdat group as well. */ | |
326 | cgraph_node::get_create (fns[2])->add_to_same_comdat_group | |
327 | (symtab_node::get (fns[0])); | |
328 | /* Emit them now that the thunks are same comdat group aliases. */ | |
329 | if (!save_defer_mangling_aliases) | |
330 | generate_mangling_aliases (); | |
331 | TREE_PUBLIC (fn) = false; | |
332 | DECL_EXTERNAL (fn) = false; | |
333 | DECL_INTERFACE_KNOWN (fn) = true; | |
334 | /* function_and_variable_visibility doesn't want !PUBLIC decls to | |
335 | have these flags set. */ | |
336 | DECL_WEAK (fn) = false; | |
337 | DECL_COMDAT (fn) = false; | |
338 | } | |
339 | ||
340 | /* Find the vtt_parm, if present. */ | |
341 | for (vtt_parmno = -1, parmno = 0, fn_parm = DECL_ARGUMENTS (fn); | |
342 | fn_parm; | |
343 | ++parmno, fn_parm = TREE_CHAIN (fn_parm)) | |
344 | { | |
345 | if (DECL_ARTIFICIAL (fn_parm) | |
346 | && DECL_NAME (fn_parm) == vtt_parm_identifier) | |
347 | { | |
348 | /* Compensate for removed in_charge parameter. */ | |
349 | vtt_parmno = parmno; | |
350 | break; | |
351 | } | |
352 | } | |
353 | ||
354 | /* Allocate an argument buffer for build_cxx_call(). | |
355 | Make sure it is large enough for any of the clones. */ | |
356 | max_parms = 0; | |
357 | FOR_EACH_CLONE (clone, fn) | |
358 | { | |
359 | int length = list_length (DECL_ARGUMENTS (fn)); | |
360 | if (length > max_parms) | |
361 | max_parms = length; | |
362 | } | |
363 | args = XALLOCAVEC (tree, max_parms); | |
364 | ||
365 | /* We know that any clones immediately follow FN in TYPE_FIELDS. */ | |
366 | FOR_EACH_CLONE (clone, fn) | |
367 | { | |
368 | tree clone_parm; | |
369 | ||
370 | /* If we've already generated a body for this clone, avoid | |
371 | duplicating it. (Is it possible for a clone-list to grow after we | |
372 | first see it?) */ | |
373 | if (DECL_SAVED_TREE (clone) || TREE_ASM_WRITTEN (clone)) | |
374 | continue; | |
375 | ||
376 | /* Start processing the function. */ | |
377 | start_preparsed_function (clone, NULL_TREE, SF_PRE_PARSED); | |
378 | ||
379 | if (clone == fns[2]) | |
380 | { | |
381 | for (clone_parm = DECL_ARGUMENTS (clone); clone_parm; | |
382 | clone_parm = TREE_CHAIN (clone_parm)) | |
383 | DECL_ABSTRACT_ORIGIN (clone_parm) = NULL_TREE; | |
384 | /* Build the delete destructor by calling complete destructor and | |
385 | delete function. */ | |
386 | build_delete_destructor_body (clone, fns[1]); | |
387 | } | |
388 | else | |
389 | { | |
390 | /* Walk parameter lists together, creating parameter list for | |
391 | call to original function. */ | |
392 | for (parmno = 0, | |
393 | fn_parm = DECL_ARGUMENTS (fn), | |
394 | fn_parm_typelist = TYPE_ARG_TYPES (TREE_TYPE (fn)), | |
395 | clone_parm = DECL_ARGUMENTS (clone); | |
396 | fn_parm; | |
397 | ++parmno, | |
398 | fn_parm = TREE_CHAIN (fn_parm)) | |
399 | { | |
400 | if (parmno == vtt_parmno && ! DECL_HAS_VTT_PARM_P (clone)) | |
401 | { | |
402 | gcc_assert (fn_parm_typelist); | |
403 | /* Clobber argument with formal parameter type. */ | |
404 | args[parmno] | |
405 | = convert (TREE_VALUE (fn_parm_typelist), | |
406 | null_pointer_node); | |
407 | } | |
408 | else if (parmno == 1 && DECL_HAS_IN_CHARGE_PARM_P (fn)) | |
409 | { | |
410 | tree in_charge | |
411 | = copy_node (in_charge_arg_for_name (DECL_NAME (clone))); | |
412 | args[parmno] = in_charge; | |
413 | } | |
414 | /* Map other parameters to their equivalents in the cloned | |
415 | function. */ | |
416 | else | |
417 | { | |
418 | gcc_assert (clone_parm); | |
419 | DECL_ABSTRACT_ORIGIN (clone_parm) = NULL; | |
420 | args[parmno] = clone_parm; | |
421 | /* Clear TREE_ADDRESSABLE on thunk arguments. */ | |
422 | TREE_ADDRESSABLE (clone_parm) = 0; | |
423 | clone_parm = TREE_CHAIN (clone_parm); | |
424 | } | |
425 | if (fn_parm_typelist) | |
426 | fn_parm_typelist = TREE_CHAIN (fn_parm_typelist); | |
427 | } | |
428 | ||
429 | /* We built this list backwards; fix now. */ | |
430 | mark_used (fn); | |
431 | call = build_cxx_call (fn, parmno, args, tf_warning_or_error); | |
432 | /* Arguments passed to the thunk by invisible reference should | |
433 | be transmitted to the callee unchanged. Do not create a | |
434 | temporary and invoke the copy constructor. The thunking | |
435 | transformation must not introduce any constructor calls. */ | |
436 | CALL_FROM_THUNK_P (call) = 1; | |
437 | block = make_node (BLOCK); | |
438 | if (targetm.cxx.cdtor_returns_this ()) | |
439 | { | |
440 | clone_result = DECL_RESULT (clone); | |
441 | modify = build2 (MODIFY_EXPR, TREE_TYPE (clone_result), | |
442 | clone_result, call); | |
443 | modify = build1 (RETURN_EXPR, void_type_node, modify); | |
444 | add_stmt (modify); | |
445 | } | |
446 | else | |
447 | { | |
448 | add_stmt (call); | |
449 | } | |
450 | bind = c_build_bind_expr (DECL_SOURCE_LOCATION (clone), | |
451 | block, cur_stmt_list); | |
452 | DECL_SAVED_TREE (clone) = push_stmt_list (); | |
453 | add_stmt (bind); | |
454 | } | |
455 | ||
456 | DECL_ABSTRACT_ORIGIN (clone) = NULL; | |
457 | expand_or_defer_fn (finish_function (/*inline_p=*/false)); | |
458 | } | |
459 | return 1; | |
460 | } | |
461 | ||
462 | /* FN is a function that has a complete body. Clone the body as | |
463 | necessary. Returns nonzero if there's no longer any need to | |
464 | process the main body. */ | |
465 | ||
466 | bool | |
467 | maybe_clone_body (tree fn) | |
468 | { | |
469 | tree comdat_group = NULL_TREE; | |
470 | tree clone; | |
471 | tree fns[3]; | |
472 | bool first = true; | |
473 | int idx; | |
474 | bool need_alias = false; | |
475 | ||
476 | /* We only clone constructors and destructors. */ | |
477 | if (!DECL_MAYBE_IN_CHARGE_CDTOR_P (fn)) | |
478 | return 0; | |
479 | ||
480 | populate_clone_array (fn, fns); | |
481 | ||
482 | /* Remember if we can't have multiple clones for some reason. We need to | |
483 | check this before we remap local static initializers in clone_body. */ | |
484 | if (!tree_versionable_function_p (fn) && fns[0] && fns[1]) | |
485 | need_alias = true; | |
486 | ||
487 | /* We know that any clones immediately follow FN in the TYPE_FIELDS | |
488 | list. */ | |
489 | push_to_top_level (); | |
490 | for (idx = 0; idx < 3; idx++) | |
491 | { | |
492 | tree parm; | |
493 | tree clone_parm; | |
494 | ||
495 | clone = fns[idx]; | |
496 | if (!clone) | |
497 | continue; | |
498 | ||
499 | /* Update CLONE's source position information to match FN's. */ | |
500 | DECL_SOURCE_LOCATION (clone) = DECL_SOURCE_LOCATION (fn); | |
501 | DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn); | |
502 | DECL_DECLARED_CONSTEXPR_P (clone) = DECL_DECLARED_CONSTEXPR_P (fn); | |
503 | DECL_COMDAT (clone) = DECL_COMDAT (fn); | |
504 | DECL_WEAK (clone) = DECL_WEAK (fn); | |
505 | ||
506 | /* We don't copy the comdat group from fn to clone because the assembler | |
507 | name of fn was corrupted by write_mangled_name by adding *INTERNAL* | |
508 | to it. By doing so, it also corrupted the comdat group. */ | |
509 | if (DECL_ONE_ONLY (fn)) | |
510 | cgraph_node::get_create (clone)->set_comdat_group (cxx_comdat_group (clone)); | |
511 | DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn); | |
512 | DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn); | |
513 | DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn); | |
514 | DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn); | |
515 | TREE_PUBLIC (clone) = TREE_PUBLIC (fn); | |
516 | DECL_VISIBILITY (clone) = DECL_VISIBILITY (fn); | |
517 | DECL_VISIBILITY_SPECIFIED (clone) = DECL_VISIBILITY_SPECIFIED (fn); | |
518 | DECL_DLLIMPORT_P (clone) = DECL_DLLIMPORT_P (fn); | |
519 | DECL_ATTRIBUTES (clone) = copy_list (DECL_ATTRIBUTES (fn)); | |
520 | DECL_DISREGARD_INLINE_LIMITS (clone) = DECL_DISREGARD_INLINE_LIMITS (fn); | |
521 | set_decl_section_name (clone, DECL_SECTION_NAME (fn)); | |
522 | ||
523 | /* Adjust the parameter names and locations. */ | |
524 | parm = DECL_ARGUMENTS (fn); | |
525 | clone_parm = DECL_ARGUMENTS (clone); | |
526 | /* Update the `this' parameter, which is always first. */ | |
527 | update_cloned_parm (parm, clone_parm, first); | |
528 | parm = DECL_CHAIN (parm); | |
529 | clone_parm = DECL_CHAIN (clone_parm); | |
530 | if (DECL_HAS_IN_CHARGE_PARM_P (fn)) | |
531 | parm = DECL_CHAIN (parm); | |
532 | if (DECL_HAS_VTT_PARM_P (fn)) | |
533 | parm = DECL_CHAIN (parm); | |
534 | if (DECL_HAS_VTT_PARM_P (clone)) | |
535 | clone_parm = DECL_CHAIN (clone_parm); | |
536 | for (; parm && clone_parm; | |
537 | parm = DECL_CHAIN (parm), clone_parm = DECL_CHAIN (clone_parm)) | |
538 | /* Update this parameter. */ | |
539 | update_cloned_parm (parm, clone_parm, first); | |
540 | } | |
541 | ||
542 | bool can_alias = can_alias_cdtor (fn); | |
543 | ||
544 | /* If we decide to turn clones into thunks, they will branch to fn. | |
545 | Must have original function available to call. */ | |
546 | if (!can_alias && maybe_thunk_body (fn, need_alias)) | |
547 | { | |
548 | pop_from_top_level (); | |
549 | /* We still need to emit the original function. */ | |
550 | return 0; | |
551 | } | |
552 | ||
553 | /* Emit the DWARF1 abstract instance. */ | |
554 | (*debug_hooks->deferred_inline_function) (fn); | |
555 | ||
556 | /* We know that any clones immediately follow FN in the TYPE_FIELDS. */ | |
557 | for (idx = 0; idx < 3; idx++) | |
558 | { | |
559 | tree parm; | |
560 | tree clone_parm; | |
561 | int parmno; | |
562 | hash_map<tree, tree> *decl_map; | |
563 | bool alias = false; | |
564 | ||
565 | clone = fns[idx]; | |
566 | if (!clone) | |
567 | continue; | |
568 | ||
569 | /* Start processing the function. */ | |
570 | start_preparsed_function (clone, NULL_TREE, SF_PRE_PARSED); | |
571 | ||
572 | /* Tell cgraph if both ctors or both dtors are known to have | |
573 | the same body. */ | |
574 | if (can_alias | |
575 | && fns[0] | |
576 | && idx == 1 | |
577 | && cgraph_node::get_create (fns[0])->create_same_body_alias | |
578 | (clone, fns[0])) | |
579 | { | |
580 | alias = true; | |
581 | if (DECL_ONE_ONLY (fns[0])) | |
582 | { | |
583 | /* For comdat base and complete cdtors put them | |
584 | into the same, *[CD]5* comdat group instead of | |
585 | *[CD][12]*. */ | |
586 | comdat_group = cdtor_comdat_group (fns[1], fns[0]); | |
587 | cgraph_node::get_create (fns[0])->set_comdat_group (comdat_group); | |
588 | if (symtab_node::get (clone)->same_comdat_group) | |
589 | symtab_node::get (clone)->remove_from_same_comdat_group (); | |
590 | symtab_node::get (clone)->add_to_same_comdat_group | |
591 | (symtab_node::get (fns[0])); | |
592 | } | |
593 | } | |
594 | ||
595 | /* Build the delete destructor by calling complete destructor | |
596 | and delete function. */ | |
597 | if (idx == 2) | |
598 | { | |
599 | build_delete_destructor_body (clone, fns[1]); | |
600 | /* If *[CD][12]* dtors go into the *[CD]5* comdat group and dtor is | |
601 | virtual, it goes into the same comdat group as well. */ | |
602 | if (comdat_group) | |
603 | cgraph_node::get_create (clone)->add_to_same_comdat_group | |
604 | (symtab_node::get (fns[0])); | |
605 | } | |
606 | else if (alias) | |
607 | /* No need to populate body. */ ; | |
608 | else | |
609 | { | |
610 | /* If we can't have multiple copies of FN (say, because there's a | |
611 | static local initialized with the address of a label), we need | |
612 | to use an alias for the complete variant. */ | |
613 | if (idx == 1 && need_alias) | |
614 | { | |
615 | if (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_set) | |
616 | sorry (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_reason, fn); | |
617 | else | |
618 | sorry ("making multiple clones of %qD", fn); | |
619 | } | |
620 | ||
621 | /* Remap the parameters. */ | |
622 | decl_map = new hash_map<tree, tree>; | |
623 | for (parmno = 0, | |
624 | parm = DECL_ARGUMENTS (fn), | |
625 | clone_parm = DECL_ARGUMENTS (clone); | |
626 | parm; | |
627 | ++parmno, | |
628 | parm = DECL_CHAIN (parm)) | |
629 | { | |
630 | /* Map the in-charge parameter to an appropriate constant. */ | |
631 | if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1) | |
632 | { | |
633 | tree in_charge; | |
634 | in_charge = in_charge_arg_for_name (DECL_NAME (clone)); | |
635 | decl_map->put (parm, in_charge); | |
636 | } | |
637 | else if (DECL_ARTIFICIAL (parm) | |
638 | && DECL_NAME (parm) == vtt_parm_identifier) | |
639 | { | |
640 | /* For a subobject constructor or destructor, the next | |
641 | argument is the VTT parameter. Remap the VTT_PARM | |
642 | from the CLONE to this parameter. */ | |
643 | if (DECL_HAS_VTT_PARM_P (clone)) | |
644 | { | |
645 | DECL_ABSTRACT_ORIGIN (clone_parm) = parm; | |
646 | decl_map->put (parm, clone_parm); | |
647 | clone_parm = DECL_CHAIN (clone_parm); | |
648 | } | |
649 | /* Otherwise, map the VTT parameter to `NULL'. */ | |
650 | else | |
651 | { | |
652 | tree t | |
653 | = fold_convert (TREE_TYPE (parm), null_pointer_node); | |
654 | decl_map->put (parm, t); | |
655 | } | |
656 | } | |
657 | /* Map other parameters to their equivalents in the cloned | |
658 | function. */ | |
659 | else | |
660 | { | |
661 | tree replacement; | |
662 | if (clone_parm) | |
663 | { | |
664 | replacement = clone_parm; | |
665 | clone_parm = DECL_CHAIN (clone_parm); | |
666 | } | |
667 | else | |
668 | { | |
669 | /* Inheriting ctors can omit parameters from the base | |
670 | clone. Replace them with null lvalues. */ | |
671 | tree reftype = build_reference_type (TREE_TYPE (parm)); | |
672 | replacement = fold_convert (reftype, null_pointer_node); | |
673 | replacement = convert_from_reference (replacement); | |
674 | } | |
675 | decl_map->put (parm, replacement); | |
676 | } | |
677 | } | |
678 | ||
679 | if (targetm.cxx.cdtor_returns_this ()) | |
680 | { | |
681 | parm = DECL_RESULT (fn); | |
682 | clone_parm = DECL_RESULT (clone); | |
683 | decl_map->put (parm, clone_parm); | |
684 | } | |
685 | ||
686 | /* Clone the body. */ | |
687 | clone_body (clone, fn, decl_map); | |
688 | ||
689 | /* Clean up. */ | |
690 | delete decl_map; | |
691 | } | |
692 | ||
693 | /* The clone can throw iff the original function can throw. */ | |
694 | cp_function_chain->can_throw = !TREE_NOTHROW (fn); | |
695 | ||
696 | /* Now, expand this function into RTL, if appropriate. */ | |
697 | finish_function (/*inline_p=*/false); | |
698 | BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn); | |
699 | if (alias) | |
700 | { | |
701 | if (expand_or_defer_fn_1 (clone)) | |
702 | emit_associated_thunks (clone); | |
703 | /* We didn't generate a body, so remove the empty one. */ | |
704 | DECL_SAVED_TREE (clone) = NULL_TREE; | |
705 | } | |
706 | else | |
707 | expand_or_defer_fn (clone); | |
708 | first = false; | |
709 | } | |
710 | pop_from_top_level (); | |
711 | ||
712 | /* We don't need to process the original function any further. */ | |
713 | return 1; | |
714 | } |