]>
Commit | Line | Data |
---|---|---|
6de9cd9a | 1 | /* Nested function decomposition for trees. |
35fd3193 | 2 | Copyright (C) 2004, 2005 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GCC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GCC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
26 | #include "rtl.h" | |
27 | #include "tm_p.h" | |
28 | #include "function.h" | |
29 | #include "tree-dump.h" | |
30 | #include "tree-inline.h" | |
eadf906f | 31 | #include "tree-gimple.h" |
6de9cd9a DN |
32 | #include "tree-iterator.h" |
33 | #include "tree-flow.h" | |
34 | #include "cgraph.h" | |
35 | #include "expr.h" | |
36 | #include "langhooks.h" | |
37 | #include "ggc.h" | |
38 | ||
39 | ||
40 | /* The object of this pass is to lower the representation of a set of nested | |
41 | functions in order to expose all of the gory details of the various | |
42 | nonlocal references. We want to do this sooner rather than later, in | |
43 | order to give us more freedom in emitting all of the functions in question. | |
44 | ||
45 | Back in olden times, when gcc was young, we developed an insanely | |
46 | complicated scheme whereby variables which were referenced nonlocally | |
47 | were forced to live in the stack of the declaring function, and then | |
48 | the nested functions magically discovered where these variables were | |
49 | placed. In order for this scheme to function properly, it required | |
50 | that the outer function be partially expanded, then we switch to | |
51 | compiling the inner function, and once done with those we switch back | |
52 | to compiling the outer function. Such delicate ordering requirements | |
53 | makes it difficult to do whole translation unit optimizations | |
54 | involving such functions. | |
55 | ||
56 | The implementation here is much more direct. Everything that can be | |
57 | referenced by an inner function is a member of an explicitly created | |
2e6ae27f | 58 | structure herein called the "nonlocal frame struct". The incoming |
6de9cd9a DN |
59 | static chain for a nested function is a pointer to this struct in |
60 | the parent. In this way, we settle on known offsets from a known | |
61 | base, and so are decoupled from the logic that places objects in the | |
62 | function's stack frame. More importantly, we don't have to wait for | |
63 | that to happen -- since the compilation of the inner function is no | |
64 | longer tied to a real stack frame, the nonlocal frame struct can be | |
65 | allocated anywhere. Which means that the outer function is now | |
66 | inlinable. | |
67 | ||
68 | Theory of operation here is very simple. Iterate over all the | |
69 | statements in all the functions (depth first) several times, | |
70 | allocating structures and fields on demand. In general we want to | |
71 | examine inner functions first, so that we can avoid making changes | |
72 | to outer functions which are unnecessary. | |
73 | ||
74 | The order of the passes matters a bit, in that later passes will be | |
75 | skipped if it is discovered that the functions don't actually interact | |
76 | at all. That is, they're nested in the lexical sense but could have | |
77 | been written as independent functions without change. */ | |
78 | ||
79 | ||
80 | struct var_map_elt | |
81 | { | |
82 | tree old; | |
83 | tree new; | |
84 | }; | |
85 | ||
86 | struct nesting_info | |
87 | { | |
88 | struct nesting_info *outer; | |
89 | struct nesting_info *inner; | |
90 | struct nesting_info *next; | |
91 | ||
92 | htab_t var_map; | |
93 | tree context; | |
94 | tree new_local_var_chain; | |
95 | tree frame_type; | |
96 | tree frame_decl; | |
97 | tree chain_field; | |
98 | tree chain_decl; | |
99 | tree nl_goto_field; | |
100 | ||
101 | bool any_parm_remapped; | |
102 | bool any_tramp_created; | |
103 | }; | |
104 | ||
105 | ||
106 | /* Hashing and equality functions for nesting_info->var_map. */ | |
107 | ||
108 | static hashval_t | |
109 | var_map_hash (const void *x) | |
110 | { | |
111 | const struct var_map_elt *a = x; | |
112 | return htab_hash_pointer (a->old); | |
113 | } | |
114 | ||
115 | static int | |
116 | var_map_eq (const void *x, const void *y) | |
117 | { | |
118 | const struct var_map_elt *a = x; | |
119 | const struct var_map_elt *b = y; | |
120 | return a->old == b->old; | |
121 | } | |
122 | ||
123 | /* We're working in so many different function contexts simultaneously, | |
124 | that create_tmp_var is dangerous. Prevent mishap. */ | |
125 | #define create_tmp_var cant_use_create_tmp_var_here_dummy | |
126 | ||
127 | /* Like create_tmp_var, except record the variable for registration at | |
128 | the given nesting level. */ | |
129 | ||
130 | static tree | |
131 | create_tmp_var_for (struct nesting_info *info, tree type, const char *prefix) | |
132 | { | |
133 | tree tmp_var; | |
134 | ||
70883f72 | 135 | /* If the type is of variable size or a type which must be created by the |
6de9cd9a DN |
136 | frontend, something is wrong. Note that we explicitly allow |
137 | incomplete types here, since we create them ourselves here. */ | |
d73d4593 | 138 | gcc_assert (!TREE_ADDRESSABLE (type)); |
1e128c5f GB |
139 | gcc_assert (!TYPE_SIZE_UNIT (type) |
140 | || TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST); | |
6de9cd9a DN |
141 | |
142 | tmp_var = create_tmp_var_raw (type, prefix); | |
143 | DECL_CONTEXT (tmp_var) = info->context; | |
144 | TREE_CHAIN (tmp_var) = info->new_local_var_chain; | |
48eb4e53 | 145 | DECL_SEEN_IN_BIND_EXPR_P (tmp_var) = 1; |
6de9cd9a DN |
146 | info->new_local_var_chain = tmp_var; |
147 | ||
148 | return tmp_var; | |
149 | } | |
150 | ||
151 | /* Take the address of EXP. Mark it for addressability as necessary. */ | |
152 | ||
8b11a64c | 153 | tree |
6de9cd9a DN |
154 | build_addr (tree exp) |
155 | { | |
156 | tree base = exp; | |
44de5aeb | 157 | |
afe84921 | 158 | while (handled_component_p (base)) |
6de9cd9a | 159 | base = TREE_OPERAND (base, 0); |
44de5aeb | 160 | |
6de9cd9a DN |
161 | if (DECL_P (base)) |
162 | TREE_ADDRESSABLE (base) = 1; | |
163 | ||
164 | return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp); | |
165 | } | |
166 | ||
167 | /* Insert FIELD into TYPE, sorted by alignment requirements. */ | |
168 | ||
169 | static void | |
170 | insert_field_into_struct (tree type, tree field) | |
171 | { | |
172 | tree *p; | |
173 | ||
174 | DECL_CONTEXT (field) = type; | |
175 | ||
176 | for (p = &TYPE_FIELDS (type); *p ; p = &TREE_CHAIN (*p)) | |
177 | if (DECL_ALIGN (field) >= DECL_ALIGN (*p)) | |
178 | break; | |
179 | ||
180 | TREE_CHAIN (field) = *p; | |
181 | *p = field; | |
182 | } | |
183 | ||
184 | /* Build or return the RECORD_TYPE that describes the frame state that is | |
185 | shared between INFO->CONTEXT and its nested functions. This record will | |
186 | not be complete until finalize_nesting_tree; up until that point we'll | |
187 | be adding fields as necessary. | |
188 | ||
189 | We also build the DECL that represents this frame in the function. */ | |
190 | ||
191 | static tree | |
192 | get_frame_type (struct nesting_info *info) | |
193 | { | |
194 | tree type = info->frame_type; | |
195 | if (!type) | |
196 | { | |
197 | char *name; | |
198 | ||
199 | type = make_node (RECORD_TYPE); | |
200 | ||
201 | name = concat ("FRAME.", | |
202 | IDENTIFIER_POINTER (DECL_NAME (info->context)), | |
203 | NULL); | |
204 | TYPE_NAME (type) = get_identifier (name); | |
205 | free (name); | |
206 | ||
207 | info->frame_type = type; | |
208 | info->frame_decl = create_tmp_var_for (info, type, "FRAME"); | |
209 | } | |
210 | return type; | |
211 | } | |
212 | ||
213 | /* Return true if DECL should be referenced by pointer in the non-local | |
214 | frame structure. */ | |
215 | ||
216 | static bool | |
217 | use_pointer_in_frame (tree decl) | |
218 | { | |
219 | if (TREE_CODE (decl) == PARM_DECL) | |
220 | { | |
221 | /* It's illegal to copy TREE_ADDRESSABLE, impossible to copy variable | |
222 | sized decls, and inefficient to copy large aggregates. Don't bother | |
223 | moving anything but scalar variables. */ | |
224 | return AGGREGATE_TYPE_P (TREE_TYPE (decl)); | |
225 | } | |
226 | else | |
227 | { | |
228 | /* Variable sized types make things "interesting" in the frame. */ | |
229 | return DECL_SIZE (decl) == NULL || !TREE_CONSTANT (DECL_SIZE (decl)); | |
230 | } | |
231 | } | |
232 | ||
233 | /* Given DECL, a non-locally accessed variable, find or create a field | |
234 | in the non-local frame structure for the given nesting context. */ | |
235 | ||
236 | static tree | |
237 | lookup_field_for_decl (struct nesting_info *info, tree decl, | |
238 | enum insert_option insert) | |
239 | { | |
240 | struct var_map_elt *elt, dummy; | |
241 | void **slot; | |
242 | tree field; | |
243 | ||
244 | dummy.old = decl; | |
245 | slot = htab_find_slot (info->var_map, &dummy, insert); | |
246 | if (!slot) | |
247 | { | |
1e128c5f | 248 | gcc_assert (insert != INSERT); |
6de9cd9a DN |
249 | return NULL; |
250 | } | |
251 | elt = *slot; | |
252 | ||
253 | if (!elt && insert == INSERT) | |
254 | { | |
255 | field = make_node (FIELD_DECL); | |
256 | DECL_NAME (field) = DECL_NAME (decl); | |
257 | ||
258 | if (use_pointer_in_frame (decl)) | |
259 | { | |
260 | TREE_TYPE (field) = build_pointer_type (TREE_TYPE (decl)); | |
261 | DECL_ALIGN (field) = TYPE_ALIGN (TREE_TYPE (field)); | |
262 | DECL_NONADDRESSABLE_P (field) = 1; | |
263 | } | |
264 | else | |
265 | { | |
266 | TREE_TYPE (field) = TREE_TYPE (decl); | |
267 | DECL_SOURCE_LOCATION (field) = DECL_SOURCE_LOCATION (decl); | |
268 | DECL_ALIGN (field) = DECL_ALIGN (decl); | |
269 | DECL_USER_ALIGN (field) = DECL_USER_ALIGN (decl); | |
270 | TREE_ADDRESSABLE (field) = TREE_ADDRESSABLE (decl); | |
271 | DECL_NONADDRESSABLE_P (field) = !TREE_ADDRESSABLE (decl); | |
272 | TREE_THIS_VOLATILE (field) = TREE_THIS_VOLATILE (decl); | |
273 | } | |
274 | ||
275 | insert_field_into_struct (get_frame_type (info), field); | |
276 | ||
277 | elt = xmalloc (sizeof (*elt)); | |
278 | elt->old = decl; | |
279 | elt->new = field; | |
280 | *slot = elt; | |
281 | ||
282 | if (TREE_CODE (decl) == PARM_DECL) | |
283 | info->any_parm_remapped = true; | |
284 | } | |
285 | else | |
286 | field = elt ? elt->new : NULL; | |
287 | ||
288 | return field; | |
289 | } | |
290 | ||
291 | /* Build or return the variable that holds the static chain within | |
292 | INFO->CONTEXT. This variable may only be used within INFO->CONTEXT. */ | |
293 | ||
294 | static tree | |
295 | get_chain_decl (struct nesting_info *info) | |
296 | { | |
297 | tree decl = info->chain_decl; | |
298 | if (!decl) | |
299 | { | |
300 | tree type; | |
301 | ||
302 | type = get_frame_type (info->outer); | |
303 | type = build_pointer_type (type); | |
304 | ||
305 | /* Note that this variable is *not* entered into any BIND_EXPR; | |
306 | the construction of this variable is handled specially in | |
7e140280 RH |
307 | expand_function_start and initialize_inlined_parameters. |
308 | Note also that it's represented as a parameter. This is more | |
309 | close to the truth, since the initial value does come from | |
310 | the caller. */ | |
311 | decl = build_decl (PARM_DECL, create_tmp_var_name ("CHAIN"), type); | |
312 | DECL_ARTIFICIAL (decl) = 1; | |
313 | DECL_IGNORED_P (decl) = 1; | |
314 | TREE_USED (decl) = 1; | |
6de9cd9a | 315 | DECL_CONTEXT (decl) = info->context; |
7e140280 | 316 | DECL_ARG_TYPE (decl) = type; |
6de9cd9a DN |
317 | |
318 | /* Tell tree-inline.c that we never write to this variable, so | |
319 | it can copy-prop the replacement value immediately. */ | |
320 | TREE_READONLY (decl) = 1; | |
321 | ||
322 | info->chain_decl = decl; | |
323 | } | |
324 | return decl; | |
325 | } | |
326 | ||
327 | /* Build or return the field within the non-local frame state that holds | |
328 | the static chain for INFO->CONTEXT. This is the way to walk back up | |
329 | multiple nesting levels. */ | |
330 | ||
331 | static tree | |
332 | get_chain_field (struct nesting_info *info) | |
333 | { | |
334 | tree field = info->chain_field; | |
335 | if (!field) | |
336 | { | |
337 | tree type = build_pointer_type (get_frame_type (info->outer)); | |
338 | ||
339 | field = make_node (FIELD_DECL); | |
340 | DECL_NAME (field) = get_identifier ("__chain"); | |
341 | TREE_TYPE (field) = type; | |
342 | DECL_ALIGN (field) = TYPE_ALIGN (type); | |
343 | DECL_NONADDRESSABLE_P (field) = 1; | |
344 | ||
345 | insert_field_into_struct (get_frame_type (info), field); | |
346 | ||
347 | info->chain_field = field; | |
348 | } | |
349 | return field; | |
350 | } | |
351 | ||
352 | /* Copy EXP into a temporary. Allocate the temporary in the context of | |
353 | INFO and insert the initialization statement before TSI. */ | |
354 | ||
355 | static tree | |
356 | init_tmp_var (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi) | |
357 | { | |
358 | tree t, stmt; | |
359 | ||
360 | t = create_tmp_var_for (info, TREE_TYPE (exp), NULL); | |
361 | stmt = build (MODIFY_EXPR, TREE_TYPE (t), t, exp); | |
362 | SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi))); | |
363 | tsi_link_before (tsi, stmt, TSI_SAME_STMT); | |
364 | ||
365 | return t; | |
366 | } | |
367 | ||
368 | /* Similarly, but only do so to force EXP to satisfy is_gimple_val. */ | |
369 | ||
370 | static tree | |
26277d41 | 371 | tsi_gimplify_val (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi) |
6de9cd9a DN |
372 | { |
373 | if (is_gimple_val (exp)) | |
374 | return exp; | |
375 | else | |
376 | return init_tmp_var (info, exp, tsi); | |
377 | } | |
378 | ||
c529c27e RH |
379 | /* Similarly, but copy from the temporary and insert the statement |
380 | after the iterator. */ | |
381 | ||
382 | static tree | |
383 | save_tmp_var (struct nesting_info *info, tree exp, | |
384 | tree_stmt_iterator *tsi) | |
385 | { | |
386 | tree t, stmt; | |
387 | ||
388 | t = create_tmp_var_for (info, TREE_TYPE (exp), NULL); | |
389 | stmt = build (MODIFY_EXPR, TREE_TYPE (t), exp, t); | |
390 | SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi))); | |
391 | tsi_link_after (tsi, stmt, TSI_SAME_STMT); | |
392 | ||
393 | return t; | |
394 | } | |
395 | ||
6de9cd9a DN |
396 | /* Build or return the type used to represent a nested function trampoline. */ |
397 | ||
398 | static GTY(()) tree trampoline_type; | |
399 | ||
400 | static tree | |
401 | get_trampoline_type (void) | |
402 | { | |
403 | tree record, t; | |
404 | unsigned align, size; | |
405 | ||
406 | if (trampoline_type) | |
407 | return trampoline_type; | |
408 | ||
409 | align = TRAMPOLINE_ALIGNMENT; | |
410 | size = TRAMPOLINE_SIZE; | |
411 | ||
412 | /* If we won't be able to guarantee alignment simply via TYPE_ALIGN, | |
413 | then allocate extra space so that we can do dynamic alignment. */ | |
414 | if (align > STACK_BOUNDARY) | |
415 | { | |
416 | size += ((align/BITS_PER_UNIT) - 1) & -(STACK_BOUNDARY/BITS_PER_UNIT); | |
417 | align = STACK_BOUNDARY; | |
418 | } | |
419 | ||
7d60be94 | 420 | t = build_index_type (build_int_cst (NULL_TREE, size - 1)); |
6de9cd9a DN |
421 | t = build_array_type (char_type_node, t); |
422 | t = build_decl (FIELD_DECL, get_identifier ("__data"), t); | |
423 | DECL_ALIGN (t) = align; | |
424 | DECL_USER_ALIGN (t) = 1; | |
425 | ||
426 | record = make_node (RECORD_TYPE); | |
427 | TYPE_NAME (record) = get_identifier ("__builtin_trampoline"); | |
428 | TYPE_FIELDS (record) = t; | |
429 | layout_type (record); | |
430 | ||
431 | return record; | |
432 | } | |
433 | ||
434 | /* Given DECL, a nested function, find or create a field in the non-local | |
435 | frame structure for a trampoline for this function. */ | |
436 | ||
437 | static tree | |
438 | lookup_tramp_for_decl (struct nesting_info *info, tree decl, | |
439 | enum insert_option insert) | |
440 | { | |
441 | struct var_map_elt *elt, dummy; | |
442 | void **slot; | |
443 | tree field; | |
444 | ||
445 | dummy.old = decl; | |
446 | slot = htab_find_slot (info->var_map, &dummy, insert); | |
447 | if (!slot) | |
448 | { | |
1e128c5f | 449 | gcc_assert (insert != INSERT); |
6de9cd9a DN |
450 | return NULL; |
451 | } | |
452 | elt = *slot; | |
453 | ||
454 | if (!elt && insert == INSERT) | |
455 | { | |
456 | field = make_node (FIELD_DECL); | |
457 | DECL_NAME (field) = DECL_NAME (decl); | |
458 | TREE_TYPE (field) = get_trampoline_type (); | |
459 | TREE_ADDRESSABLE (field) = 1; | |
460 | ||
461 | insert_field_into_struct (get_frame_type (info), field); | |
462 | ||
463 | elt = xmalloc (sizeof (*elt)); | |
464 | elt->old = decl; | |
465 | elt->new = field; | |
466 | *slot = elt; | |
467 | ||
468 | info->any_tramp_created = true; | |
469 | } | |
470 | else | |
471 | field = elt ? elt->new : NULL; | |
472 | ||
473 | return field; | |
474 | } | |
475 | ||
476 | /* Build or return the field within the non-local frame state that holds | |
477 | the non-local goto "jmp_buf". The buffer itself is maintained by the | |
478 | rtl middle-end as dynamic stack space is allocated. */ | |
479 | ||
480 | static tree | |
481 | get_nl_goto_field (struct nesting_info *info) | |
482 | { | |
483 | tree field = info->nl_goto_field; | |
484 | if (!field) | |
485 | { | |
486 | unsigned size; | |
487 | tree type; | |
488 | ||
489 | /* For __builtin_nonlocal_goto, we need N words. The first is the | |
490 | frame pointer, the rest is for the target's stack pointer save | |
1ea7e6ad | 491 | area. The number of words is controlled by STACK_SAVEAREA_MODE; |
6de9cd9a DN |
492 | not the best interface, but it'll do for now. */ |
493 | if (Pmode == ptr_mode) | |
494 | type = ptr_type_node; | |
495 | else | |
496 | type = lang_hooks.types.type_for_mode (Pmode, 1); | |
497 | ||
498 | size = GET_MODE_SIZE (STACK_SAVEAREA_MODE (SAVE_NONLOCAL)); | |
499 | size = size / GET_MODE_SIZE (Pmode); | |
500 | size = size + 1; | |
501 | ||
4a90aeeb | 502 | type = build_array_type |
7d60be94 | 503 | (type, build_index_type (build_int_cst (NULL_TREE, size))); |
6de9cd9a DN |
504 | |
505 | field = make_node (FIELD_DECL); | |
506 | DECL_NAME (field) = get_identifier ("__nl_goto_buf"); | |
507 | TREE_TYPE (field) = type; | |
508 | DECL_ALIGN (field) = TYPE_ALIGN (type); | |
509 | TREE_ADDRESSABLE (field) = 1; | |
510 | ||
511 | insert_field_into_struct (get_frame_type (info), field); | |
512 | ||
513 | info->nl_goto_field = field; | |
514 | } | |
515 | ||
516 | return field; | |
517 | } | |
518 | \f | |
519 | /* Convenience routines to walk all statements of a gimple function. | |
520 | ||
521 | For each statement, we invoke CALLBACK via walk_tree. The passed | |
522 | data is a walk_stmt_info structure. Of note here is a TSI that | |
523 | points to the current statement being walked. The VAL_ONLY flag | |
524 | that indicates whether the *TP being examined may be replaced | |
525 | with something that matches is_gimple_val (if true) or something | |
526 | slightly more complicated (if false). "Something" technically | |
527 | means the common subset of is_gimple_lvalue and is_gimple_rhs, | |
528 | but we never try to form anything more complicated than that, so | |
529 | we don't bother checking. */ | |
530 | ||
531 | struct walk_stmt_info | |
532 | { | |
533 | walk_tree_fn callback; | |
534 | tree_stmt_iterator tsi; | |
535 | struct nesting_info *info; | |
536 | bool val_only; | |
c529c27e | 537 | bool is_lhs; |
a3ed9870 | 538 | bool changed; |
6de9cd9a DN |
539 | }; |
540 | ||
541 | /* A subroutine of walk_function. Iterate over all sub-statements of *TP. */ | |
542 | ||
543 | static void | |
544 | walk_stmts (struct walk_stmt_info *wi, tree *tp) | |
545 | { | |
546 | tree t = *tp; | |
547 | if (!t) | |
548 | return; | |
549 | ||
550 | switch (TREE_CODE (t)) | |
551 | { | |
552 | case STATEMENT_LIST: | |
553 | { | |
554 | tree_stmt_iterator i; | |
555 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
556 | { | |
557 | wi->tsi = i; | |
558 | walk_stmts (wi, tsi_stmt_ptr (i)); | |
559 | } | |
560 | } | |
561 | break; | |
562 | ||
563 | case COND_EXPR: | |
564 | walk_tree (&COND_EXPR_COND (t), wi->callback, wi, NULL); | |
565 | walk_stmts (wi, &COND_EXPR_THEN (t)); | |
566 | walk_stmts (wi, &COND_EXPR_ELSE (t)); | |
567 | break; | |
568 | case CATCH_EXPR: | |
569 | walk_stmts (wi, &CATCH_BODY (t)); | |
44de5aeb | 570 | break; |
6de9cd9a DN |
571 | case EH_FILTER_EXPR: |
572 | walk_stmts (wi, &EH_FILTER_FAILURE (t)); | |
573 | break; | |
574 | case TRY_CATCH_EXPR: | |
575 | case TRY_FINALLY_EXPR: | |
576 | walk_stmts (wi, &TREE_OPERAND (t, 0)); | |
577 | walk_stmts (wi, &TREE_OPERAND (t, 1)); | |
578 | break; | |
579 | case BIND_EXPR: | |
580 | walk_stmts (wi, &BIND_EXPR_BODY (t)); | |
581 | break; | |
582 | ||
583 | case RETURN_EXPR: | |
584 | walk_stmts (wi, &TREE_OPERAND (t, 0)); | |
585 | break; | |
586 | ||
587 | case MODIFY_EXPR: | |
c529c27e RH |
588 | /* A formal temporary lhs may use a COMPONENT_REF rhs. */ |
589 | wi->val_only = !is_gimple_formal_tmp_var (TREE_OPERAND (t, 0)); | |
6de9cd9a | 590 | walk_tree (&TREE_OPERAND (t, 1), wi->callback, wi, NULL); |
c529c27e RH |
591 | |
592 | /* If the rhs is appropriate for a memory, we may use a | |
593 | COMPONENT_REF on the lhs. */ | |
594 | wi->val_only = !is_gimple_mem_rhs (TREE_OPERAND (t, 1)); | |
595 | wi->is_lhs = true; | |
596 | walk_tree (&TREE_OPERAND (t, 0), wi->callback, wi, NULL); | |
597 | ||
6de9cd9a | 598 | wi->val_only = true; |
c529c27e | 599 | wi->is_lhs = false; |
6de9cd9a DN |
600 | break; |
601 | ||
602 | default: | |
603 | wi->val_only = true; | |
604 | walk_tree (tp, wi->callback, wi, NULL); | |
605 | break; | |
606 | } | |
607 | } | |
608 | ||
609 | /* Invoke CALLBACK on all statements of INFO->CONTEXT. */ | |
610 | ||
611 | static void | |
612 | walk_function (walk_tree_fn callback, struct nesting_info *info) | |
613 | { | |
614 | struct walk_stmt_info wi; | |
615 | ||
616 | memset (&wi, 0, sizeof (wi)); | |
617 | wi.callback = callback; | |
618 | wi.info = info; | |
619 | wi.val_only = true; | |
620 | ||
621 | walk_stmts (&wi, &DECL_SAVED_TREE (info->context)); | |
622 | } | |
623 | ||
624 | /* Similarly for ROOT and all functions nested underneath, depth first. */ | |
625 | ||
626 | static void | |
627 | walk_all_functions (walk_tree_fn callback, struct nesting_info *root) | |
628 | { | |
629 | do | |
630 | { | |
631 | if (root->inner) | |
632 | walk_all_functions (callback, root->inner); | |
633 | walk_function (callback, root); | |
634 | root = root->next; | |
635 | } | |
636 | while (root); | |
637 | } | |
6de9cd9a | 638 | \f |
35fd3193 | 639 | /* We have to check for a fairly pathological case. The operands of function |
ab1a8620 RK |
640 | nested function are to be interpreted in the context of the enclosing |
641 | function. So if any are variably-sized, they will get remapped when the | |
642 | enclosing function is inlined. But that remapping would also have to be | |
643 | done in the types of the PARM_DECLs of the nested function, meaning the | |
644 | argument types of that function will disagree with the arguments in the | |
645 | calls to that function. So we'd either have to make a copy of the nested | |
646 | function corresponding to each time the enclosing function was inlined or | |
647 | add a VIEW_CONVERT_EXPR to each such operand for each call to the nested | |
648 | function. The former is not practical. The latter would still require | |
649 | detecting this case to know when to add the conversions. So, for now at | |
650 | least, we don't inline such an enclosing function. | |
651 | ||
652 | We have to do that check recursively, so here return indicating whether | |
653 | FNDECL has such a nested function. ORIG_FN is the function we were | |
654 | trying to inline to use for checking whether any argument is variably | |
655 | modified by anything in it. | |
656 | ||
657 | It would be better to do this in tree-inline.c so that we could give | |
658 | the appropriate warning for why a function can't be inlined, but that's | |
659 | too late since the nesting structure has already been flattened and | |
660 | adding a flag just to record this fact seems a waste of a flag. */ | |
661 | ||
662 | static bool | |
663 | check_for_nested_with_variably_modified (tree fndecl, tree orig_fndecl) | |
664 | { | |
665 | struct cgraph_node *cgn = cgraph_node (fndecl); | |
666 | tree arg; | |
667 | ||
668 | for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) | |
669 | { | |
670 | for (arg = DECL_ARGUMENTS (cgn->decl); arg; arg = TREE_CHAIN (arg)) | |
671 | if (variably_modified_type_p (TREE_TYPE (arg), 0), orig_fndecl) | |
672 | return true; | |
673 | ||
674 | if (check_for_nested_with_variably_modified (cgn->decl, orig_fndecl)) | |
675 | return true; | |
676 | } | |
677 | ||
678 | return false; | |
679 | } | |
680 | ||
6de9cd9a DN |
681 | /* Construct our local datastructure describing the function nesting |
682 | tree rooted by CGN. */ | |
683 | ||
684 | static struct nesting_info * | |
685 | create_nesting_tree (struct cgraph_node *cgn) | |
686 | { | |
687 | struct nesting_info *info = xcalloc (1, sizeof (*info)); | |
688 | info->var_map = htab_create (7, var_map_hash, var_map_eq, free); | |
689 | info->context = cgn->decl; | |
690 | ||
691 | for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) | |
692 | { | |
693 | struct nesting_info *sub = create_nesting_tree (cgn); | |
694 | sub->outer = info; | |
695 | sub->next = info->inner; | |
696 | info->inner = sub; | |
697 | } | |
698 | ||
ab1a8620 RK |
699 | /* See discussion at check_for_nested_with_variably_modified for a |
700 | discussion of why this has to be here. */ | |
701 | if (check_for_nested_with_variably_modified (info->context, info->context)) | |
702 | DECL_UNINLINABLE (info->context) = true; | |
703 | ||
6de9cd9a DN |
704 | return info; |
705 | } | |
706 | ||
707 | /* Return an expression computing the static chain for TARGET_CONTEXT | |
708 | from INFO->CONTEXT. Insert any necessary computations before TSI. */ | |
709 | ||
710 | static tree | |
711 | get_static_chain (struct nesting_info *info, tree target_context, | |
712 | tree_stmt_iterator *tsi) | |
713 | { | |
714 | struct nesting_info *i; | |
715 | tree x; | |
716 | ||
717 | if (info->context == target_context) | |
718 | { | |
719 | x = build_addr (info->frame_decl); | |
720 | } | |
721 | else | |
722 | { | |
723 | x = get_chain_decl (info); | |
724 | ||
725 | for (i = info->outer; i->context != target_context; i = i->outer) | |
726 | { | |
727 | tree field = get_chain_field (i); | |
728 | ||
729 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
44de5aeb | 730 | x = build (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE); |
6de9cd9a DN |
731 | x = init_tmp_var (info, x, tsi); |
732 | } | |
733 | } | |
734 | ||
735 | return x; | |
736 | } | |
737 | ||
738 | /* Return an expression referencing FIELD from TARGET_CONTEXT's non-local | |
739 | frame as seen from INFO->CONTEXT. Insert any necessary computations | |
740 | before TSI. */ | |
741 | ||
742 | static tree | |
743 | get_frame_field (struct nesting_info *info, tree target_context, | |
744 | tree field, tree_stmt_iterator *tsi) | |
745 | { | |
746 | struct nesting_info *i; | |
747 | tree x; | |
748 | ||
749 | if (info->context == target_context) | |
750 | { | |
751 | /* Make sure frame_decl gets created. */ | |
752 | (void) get_frame_type (info); | |
753 | x = info->frame_decl; | |
754 | } | |
755 | else | |
756 | { | |
757 | x = get_chain_decl (info); | |
758 | ||
759 | for (i = info->outer; i->context != target_context; i = i->outer) | |
760 | { | |
761 | tree field = get_chain_field (i); | |
762 | ||
763 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
44de5aeb | 764 | x = build (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE); |
6de9cd9a DN |
765 | x = init_tmp_var (info, x, tsi); |
766 | } | |
767 | ||
768 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
769 | } | |
770 | ||
44de5aeb | 771 | x = build (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE); |
6de9cd9a DN |
772 | return x; |
773 | } | |
774 | ||
775 | /* Called via walk_function+walk_tree, rewrite all references to VAR | |
776 | and PARM_DECLs that belong to outer functions. | |
777 | ||
778 | The rewrite will involve some number of structure accesses back up | |
779 | the static chain. E.g. for a variable FOO up one nesting level it'll | |
780 | be CHAIN->FOO. For two levels it'll be CHAIN->__chain->FOO. Further | |
781 | indirections apply to decls for which use_pointer_in_frame is true. */ | |
782 | ||
783 | static tree | |
784 | convert_nonlocal_reference (tree *tp, int *walk_subtrees, void *data) | |
785 | { | |
786 | struct walk_stmt_info *wi = data; | |
787 | struct nesting_info *info = wi->info; | |
788 | tree t = *tp; | |
789 | ||
790 | *walk_subtrees = 0; | |
791 | switch (TREE_CODE (t)) | |
792 | { | |
793 | case VAR_DECL: | |
794 | /* Non-automatic variables are never processed. */ | |
795 | if (TREE_STATIC (t) || DECL_EXTERNAL (t)) | |
796 | break; | |
797 | /* FALLTHRU */ | |
798 | ||
799 | case PARM_DECL: | |
800 | if (decl_function_context (t) != info->context) | |
801 | { | |
802 | tree target_context = decl_function_context (t); | |
803 | struct nesting_info *i; | |
804 | tree x; | |
a3ed9870 | 805 | wi->changed = true; |
6de9cd9a DN |
806 | |
807 | for (i = info->outer; i->context != target_context; i = i->outer) | |
808 | continue; | |
809 | x = lookup_field_for_decl (i, t, INSERT); | |
810 | x = get_frame_field (info, target_context, x, &wi->tsi); | |
811 | if (use_pointer_in_frame (t)) | |
812 | { | |
813 | x = init_tmp_var (info, x, &wi->tsi); | |
814 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
815 | } | |
c529c27e | 816 | |
6de9cd9a | 817 | if (wi->val_only) |
c529c27e RH |
818 | { |
819 | if (wi->is_lhs) | |
820 | x = save_tmp_var (info, x, &wi->tsi); | |
821 | else | |
822 | x = init_tmp_var (info, x, &wi->tsi); | |
823 | } | |
6de9cd9a DN |
824 | |
825 | *tp = x; | |
826 | } | |
827 | break; | |
828 | ||
829 | case GOTO_EXPR: | |
830 | /* Don't walk non-local gotos for now. */ | |
831 | if (TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL) | |
832 | { | |
833 | *walk_subtrees = 1; | |
834 | wi->val_only = true; | |
c529c27e | 835 | wi->is_lhs = false; |
6de9cd9a DN |
836 | } |
837 | break; | |
838 | ||
839 | case LABEL_DECL: | |
840 | /* We're taking the address of a label from a parent function, but | |
841 | this is not itself a non-local goto. Mark the label such that it | |
842 | will not be deleted, much as we would with a label address in | |
843 | static storage. */ | |
844 | if (decl_function_context (t) != info->context) | |
845 | FORCED_LABEL (t) = 1; | |
846 | break; | |
847 | ||
848 | case ADDR_EXPR: | |
849 | { | |
850 | bool save_val_only = wi->val_only; | |
6de9cd9a DN |
851 | |
852 | wi->val_only = false; | |
c529c27e RH |
853 | wi->is_lhs = false; |
854 | wi->changed = false; | |
6de9cd9a DN |
855 | walk_tree (&TREE_OPERAND (t, 0), convert_nonlocal_reference, wi, NULL); |
856 | wi->val_only = true; | |
857 | ||
a3ed9870 | 858 | if (wi->changed) |
6de9cd9a DN |
859 | { |
860 | /* If we changed anything, then TREE_INVARIANT is be wrong, | |
861 | since we're no longer directly referencing a decl. */ | |
a3ed9870 | 862 | recompute_tree_invarant_for_addr_expr (t); |
6de9cd9a DN |
863 | |
864 | /* If the callback converted the address argument in a context | |
865 | where we only accept variables (and min_invariant, presumably), | |
866 | then compute the address into a temporary. */ | |
867 | if (save_val_only) | |
26277d41 | 868 | *tp = tsi_gimplify_val (wi->info, t, &wi->tsi); |
6de9cd9a DN |
869 | } |
870 | } | |
871 | break; | |
872 | ||
6de9cd9a DN |
873 | case REALPART_EXPR: |
874 | case IMAGPART_EXPR: | |
8f44bc38 | 875 | case COMPONENT_REF: |
6de9cd9a | 876 | case ARRAY_REF: |
44de5aeb | 877 | case ARRAY_RANGE_REF: |
6de9cd9a | 878 | case BIT_FIELD_REF: |
70883f72 RK |
879 | /* Go down this entire nest and just look at the final prefix and |
880 | anything that describes the references. Otherwise, we lose track | |
881 | of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value. */ | |
6de9cd9a | 882 | wi->val_only = true; |
c529c27e | 883 | wi->is_lhs = false; |
afe84921 | 884 | for (; handled_component_p (t); tp = &TREE_OPERAND (t, 0), t = *tp) |
70883f72 RK |
885 | { |
886 | if (TREE_CODE (t) == COMPONENT_REF) | |
887 | walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi, | |
888 | NULL); | |
889 | else if (TREE_CODE (t) == ARRAY_REF | |
890 | || TREE_CODE (t) == ARRAY_RANGE_REF) | |
891 | { | |
892 | walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi, | |
893 | NULL); | |
894 | walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi, | |
895 | NULL); | |
896 | walk_tree (&TREE_OPERAND (t, 3), convert_nonlocal_reference, wi, | |
897 | NULL); | |
898 | } | |
899 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
900 | { | |
901 | walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi, | |
902 | NULL); | |
903 | walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi, | |
904 | NULL); | |
905 | } | |
906 | } | |
907 | wi->val_only = false; | |
908 | walk_tree (tp, convert_nonlocal_reference, wi, NULL); | |
6de9cd9a DN |
909 | break; |
910 | ||
911 | default: | |
6615c446 | 912 | if (!IS_TYPE_OR_DECL_P (t)) |
6de9cd9a DN |
913 | { |
914 | *walk_subtrees = 1; | |
915 | wi->val_only = true; | |
c529c27e | 916 | wi->is_lhs = false; |
6de9cd9a DN |
917 | } |
918 | break; | |
919 | } | |
920 | ||
921 | return NULL_TREE; | |
922 | } | |
923 | ||
924 | /* Called via walk_function+walk_tree, rewrite all references to VAR | |
925 | and PARM_DECLs that were referenced by inner nested functions. | |
926 | The rewrite will be a structure reference to the local frame variable. */ | |
927 | ||
928 | static tree | |
929 | convert_local_reference (tree *tp, int *walk_subtrees, void *data) | |
930 | { | |
931 | struct walk_stmt_info *wi = data; | |
932 | struct nesting_info *info = wi->info; | |
1a186ec5 | 933 | tree t = *tp, field, x; |
6de9cd9a DN |
934 | |
935 | switch (TREE_CODE (t)) | |
936 | { | |
937 | case VAR_DECL: | |
938 | /* Non-automatic variables are never processed. */ | |
939 | if (TREE_STATIC (t) || DECL_EXTERNAL (t)) | |
940 | break; | |
941 | /* FALLTHRU */ | |
942 | ||
943 | case PARM_DECL: | |
944 | if (decl_function_context (t) == info->context) | |
945 | { | |
946 | /* If we copied a pointer to the frame, then the original decl | |
947 | is used unchanged in the parent function. */ | |
948 | if (use_pointer_in_frame (t)) | |
949 | break; | |
950 | ||
951 | /* No need to transform anything if no child references the | |
952 | variable. */ | |
953 | field = lookup_field_for_decl (info, t, NO_INSERT); | |
954 | if (!field) | |
955 | break; | |
a3ed9870 | 956 | wi->changed = true; |
6de9cd9a DN |
957 | |
958 | x = get_frame_field (info, info->context, field, &wi->tsi); | |
c529c27e | 959 | |
6de9cd9a | 960 | if (wi->val_only) |
c529c27e RH |
961 | { |
962 | if (wi->is_lhs) | |
963 | x = save_tmp_var (info, x, &wi->tsi); | |
964 | else | |
965 | x = init_tmp_var (info, x, &wi->tsi); | |
966 | } | |
967 | ||
6de9cd9a DN |
968 | *tp = x; |
969 | } | |
970 | break; | |
971 | ||
972 | case ADDR_EXPR: | |
973 | { | |
974 | bool save_val_only = wi->val_only; | |
6de9cd9a DN |
975 | |
976 | wi->val_only = false; | |
c529c27e RH |
977 | wi->is_lhs = false; |
978 | wi->changed = false; | |
6de9cd9a DN |
979 | walk_tree (&TREE_OPERAND (t, 0), convert_local_reference, wi, NULL); |
980 | wi->val_only = save_val_only; | |
981 | ||
982 | /* If we converted anything ... */ | |
a3ed9870 | 983 | if (wi->changed) |
6de9cd9a DN |
984 | { |
985 | /* Then the frame decl is now addressable. */ | |
986 | TREE_ADDRESSABLE (info->frame_decl) = 1; | |
a3ed9870 AP |
987 | |
988 | recompute_tree_invarant_for_addr_expr (t); | |
6de9cd9a DN |
989 | |
990 | /* If we are in a context where we only accept values, then | |
991 | compute the address into a temporary. */ | |
992 | if (save_val_only) | |
26277d41 | 993 | *tp = tsi_gimplify_val (wi->info, t, &wi->tsi); |
6de9cd9a DN |
994 | } |
995 | } | |
996 | break; | |
997 | ||
6de9cd9a DN |
998 | case REALPART_EXPR: |
999 | case IMAGPART_EXPR: | |
8f44bc38 | 1000 | case COMPONENT_REF: |
6de9cd9a | 1001 | case ARRAY_REF: |
44de5aeb | 1002 | case ARRAY_RANGE_REF: |
6de9cd9a | 1003 | case BIT_FIELD_REF: |
70883f72 RK |
1004 | /* Go down this entire nest and just look at the final prefix and |
1005 | anything that describes the references. Otherwise, we lose track | |
1006 | of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value. */ | |
6de9cd9a | 1007 | wi->val_only = true; |
c529c27e | 1008 | wi->is_lhs = false; |
afe84921 | 1009 | for (; handled_component_p (t); tp = &TREE_OPERAND (t, 0), t = *tp) |
70883f72 RK |
1010 | { |
1011 | if (TREE_CODE (t) == COMPONENT_REF) | |
1012 | walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi, | |
1013 | NULL); | |
1014 | else if (TREE_CODE (t) == ARRAY_REF | |
1015 | || TREE_CODE (t) == ARRAY_RANGE_REF) | |
1016 | { | |
1017 | walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi, | |
1018 | NULL); | |
1019 | walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi, | |
1020 | NULL); | |
1021 | walk_tree (&TREE_OPERAND (t, 3), convert_local_reference, wi, | |
1022 | NULL); | |
1023 | } | |
1024 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
1025 | { | |
1026 | walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi, | |
1027 | NULL); | |
1028 | walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi, | |
1029 | NULL); | |
1030 | } | |
1031 | } | |
1032 | wi->val_only = false; | |
1033 | walk_tree (tp, convert_local_reference, wi, NULL); | |
6de9cd9a DN |
1034 | break; |
1035 | ||
1036 | default: | |
6615c446 | 1037 | if (!IS_TYPE_OR_DECL_P (t)) |
6de9cd9a DN |
1038 | { |
1039 | *walk_subtrees = 1; | |
1040 | wi->val_only = true; | |
c529c27e | 1041 | wi->is_lhs = false; |
6de9cd9a DN |
1042 | } |
1043 | break; | |
1044 | } | |
1045 | ||
1046 | return NULL_TREE; | |
1047 | } | |
1048 | ||
1049 | /* Called via walk_function+walk_tree, rewrite all GOTO_EXPRs that | |
1050 | reference labels from outer functions. The rewrite will be a | |
1051 | call to __builtin_nonlocal_goto. */ | |
1052 | ||
1053 | static tree | |
1054 | convert_nl_goto_reference (tree *tp, int *walk_subtrees, void *data) | |
1055 | { | |
1056 | struct walk_stmt_info *wi = data; | |
1057 | struct nesting_info *info = wi->info, *i; | |
1058 | tree t = *tp, label, new_label, target_context, x, arg, field; | |
1059 | struct var_map_elt *elt; | |
1060 | void **slot; | |
1061 | ||
1062 | *walk_subtrees = 0; | |
1063 | if (TREE_CODE (t) != GOTO_EXPR) | |
1064 | return NULL_TREE; | |
1065 | label = GOTO_DESTINATION (t); | |
1066 | if (TREE_CODE (label) != LABEL_DECL) | |
1067 | return NULL_TREE; | |
1068 | target_context = decl_function_context (label); | |
1069 | if (target_context == info->context) | |
1070 | return NULL_TREE; | |
1071 | ||
1072 | for (i = info->outer; target_context != i->context; i = i->outer) | |
1073 | continue; | |
1074 | ||
1075 | /* The original user label may also be use for a normal goto, therefore | |
1076 | we must create a new label that will actually receive the abnormal | |
1077 | control transfer. This new label will be marked LABEL_NONLOCAL; this | |
1ea7e6ad | 1078 | mark will trigger proper behavior in the cfg, as well as cause the |
6de9cd9a DN |
1079 | (hairy target-specific) non-local goto receiver code to be generated |
1080 | when we expand rtl. */ | |
1081 | new_label = create_artificial_label (); | |
1082 | DECL_NONLOCAL (new_label) = 1; | |
1083 | ||
1084 | /* Enter this association into var_map so that we can insert the new | |
1085 | label into the IL during a second pass. */ | |
1086 | elt = xmalloc (sizeof (*elt)); | |
1087 | elt->old = label; | |
1088 | elt->new = new_label; | |
1089 | slot = htab_find_slot (i->var_map, elt, INSERT); | |
1090 | *slot = elt; | |
1091 | ||
1092 | /* Build: __builtin_nl_goto(new_label, &chain->nl_goto_field). */ | |
1093 | field = get_nl_goto_field (i); | |
1094 | x = get_frame_field (info, target_context, field, &wi->tsi); | |
1095 | x = build_addr (x); | |
26277d41 | 1096 | x = tsi_gimplify_val (info, x, &wi->tsi); |
6de9cd9a DN |
1097 | arg = tree_cons (NULL, x, NULL); |
1098 | x = build_addr (new_label); | |
1099 | arg = tree_cons (NULL, x, arg); | |
1100 | x = implicit_built_in_decls[BUILT_IN_NONLOCAL_GOTO]; | |
1101 | x = build_function_call_expr (x, arg); | |
1102 | ||
1103 | SET_EXPR_LOCUS (x, EXPR_LOCUS (tsi_stmt (wi->tsi))); | |
1104 | *tsi_stmt_ptr (wi->tsi) = x; | |
1105 | ||
1106 | return NULL_TREE; | |
1107 | } | |
1108 | ||
1109 | /* Called via walk_function+walk_tree, rewrite all LABEL_EXPRs that | |
1110 | are referenced via nonlocal goto from a nested function. The rewrite | |
1111 | will involve installing a newly generated DECL_NONLOCAL label, and | |
1112 | (potentially) a branch around the rtl gunk that is assumed to be | |
1113 | attached to such a label. */ | |
1114 | ||
1115 | static tree | |
1116 | convert_nl_goto_receiver (tree *tp, int *walk_subtrees, void *data) | |
1117 | { | |
1118 | struct walk_stmt_info *wi = data; | |
1119 | struct nesting_info *info = wi->info; | |
1120 | tree t = *tp, label, new_label, x; | |
1121 | struct var_map_elt *elt, dummy; | |
1122 | tree_stmt_iterator tmp_tsi; | |
1123 | ||
1124 | *walk_subtrees = 0; | |
1125 | if (TREE_CODE (t) != LABEL_EXPR) | |
1126 | return NULL_TREE; | |
1127 | label = LABEL_EXPR_LABEL (t); | |
1128 | ||
1129 | dummy.old = label; | |
1130 | elt = htab_find (info->var_map, &dummy); | |
1131 | if (!elt) | |
1132 | return NULL_TREE; | |
1133 | new_label = elt->new; | |
1134 | ||
1135 | /* If there's any possibility that the previous statement falls through, | |
1136 | then we must branch around the new non-local label. */ | |
1137 | tmp_tsi = wi->tsi; | |
1138 | tsi_prev (&tmp_tsi); | |
1139 | if (tsi_end_p (tmp_tsi) || block_may_fallthru (tsi_stmt (tmp_tsi))) | |
1140 | { | |
1141 | x = build1 (GOTO_EXPR, void_type_node, label); | |
1142 | tsi_link_before (&wi->tsi, x, TSI_SAME_STMT); | |
1143 | } | |
1144 | x = build1 (LABEL_EXPR, void_type_node, new_label); | |
1145 | tsi_link_before (&wi->tsi, x, TSI_SAME_STMT); | |
1146 | ||
1147 | return NULL_TREE; | |
1148 | } | |
1149 | ||
1150 | /* Called via walk_function+walk_tree, rewrite all references to addresses | |
1151 | of nested functions that require the use of trampolines. The rewrite | |
1152 | will involve a reference a trampoline generated for the occasion. */ | |
1153 | ||
1154 | static tree | |
1155 | convert_tramp_reference (tree *tp, int *walk_subtrees, void *data) | |
1156 | { | |
1157 | struct walk_stmt_info *wi = data; | |
1158 | struct nesting_info *info = wi->info, *i; | |
1159 | tree t = *tp, decl, target_context, x, arg; | |
1160 | ||
1161 | *walk_subtrees = 0; | |
1162 | switch (TREE_CODE (t)) | |
1163 | { | |
1164 | case ADDR_EXPR: | |
1165 | /* Build | |
1166 | T.1 = &CHAIN->tramp; | |
1167 | T.2 = __builtin_adjust_trampoline (T.1); | |
1168 | T.3 = (func_type)T.2; | |
1169 | */ | |
1170 | ||
1171 | decl = TREE_OPERAND (t, 0); | |
1172 | if (TREE_CODE (decl) != FUNCTION_DECL) | |
1173 | break; | |
1174 | ||
1175 | /* Only need to process nested functions. */ | |
1176 | target_context = decl_function_context (decl); | |
1177 | if (!target_context) | |
1178 | break; | |
1179 | ||
1180 | /* If the nested function doesn't use a static chain, then | |
1181 | it doesn't need a trampoline. */ | |
1182 | if (DECL_NO_STATIC_CHAIN (decl)) | |
1183 | break; | |
1184 | ||
1185 | /* Lookup the immediate parent of the callee, as that's where | |
1186 | we need to insert the trampoline. */ | |
1187 | for (i = info; i->context != target_context; i = i->outer) | |
1188 | continue; | |
1189 | x = lookup_tramp_for_decl (i, decl, INSERT); | |
1190 | ||
1191 | /* Compute the address of the field holding the trampoline. */ | |
1192 | x = get_frame_field (info, target_context, x, &wi->tsi); | |
1193 | x = build_addr (x); | |
26277d41 | 1194 | x = tsi_gimplify_val (info, x, &wi->tsi); |
6de9cd9a DN |
1195 | arg = tree_cons (NULL, x, NULL); |
1196 | ||
1197 | /* Do machine-specific ugliness. Normally this will involve | |
1198 | computing extra alignment, but it can really be anything. */ | |
1199 | x = implicit_built_in_decls[BUILT_IN_ADJUST_TRAMPOLINE]; | |
1200 | x = build_function_call_expr (x, arg); | |
1201 | x = init_tmp_var (info, x, &wi->tsi); | |
1202 | ||
1203 | /* Cast back to the proper function type. */ | |
1204 | x = build1 (NOP_EXPR, TREE_TYPE (t), x); | |
1205 | x = init_tmp_var (info, x, &wi->tsi); | |
1206 | ||
1207 | *tp = x; | |
1208 | break; | |
1209 | ||
1210 | case CALL_EXPR: | |
1211 | /* Only walk call arguments, lest we generate trampolines for | |
1212 | direct calls. */ | |
1213 | walk_tree (&TREE_OPERAND (t, 1), convert_tramp_reference, wi, NULL); | |
1214 | break; | |
1215 | ||
1216 | default: | |
6615c446 | 1217 | if (!IS_TYPE_OR_DECL_P (t)) |
6de9cd9a DN |
1218 | *walk_subtrees = 1; |
1219 | break; | |
1220 | } | |
1221 | ||
1222 | return NULL_TREE; | |
1223 | } | |
1224 | ||
1225 | /* Called via walk_function+walk_tree, rewrite all CALL_EXPRs that | |
1226 | reference nested functions to make sure that the static chain is | |
1227 | set up properly for the call. */ | |
1228 | ||
1229 | static tree | |
1230 | convert_call_expr (tree *tp, int *walk_subtrees, void *data) | |
1231 | { | |
1232 | struct walk_stmt_info *wi = data; | |
1233 | struct nesting_info *info = wi->info; | |
1234 | tree t = *tp, decl, target_context; | |
1235 | ||
1236 | *walk_subtrees = 0; | |
1237 | switch (TREE_CODE (t)) | |
1238 | { | |
1239 | case CALL_EXPR: | |
1240 | decl = get_callee_fndecl (t); | |
1241 | if (!decl) | |
1242 | break; | |
1243 | target_context = decl_function_context (decl); | |
1244 | if (target_context && !DECL_NO_STATIC_CHAIN (decl)) | |
1245 | TREE_OPERAND (t, 2) | |
1246 | = get_static_chain (info, target_context, &wi->tsi); | |
1247 | break; | |
1248 | ||
1249 | case RETURN_EXPR: | |
1250 | case MODIFY_EXPR: | |
d25cee4d RH |
1251 | case WITH_SIZE_EXPR: |
1252 | /* Only return modify and with_size_expr may contain calls. */ | |
6de9cd9a DN |
1253 | *walk_subtrees = 1; |
1254 | break; | |
1255 | ||
1256 | default: | |
1257 | break; | |
1258 | } | |
1259 | ||
1260 | return NULL_TREE; | |
1261 | } | |
1262 | ||
1263 | /* Walk the nesting tree starting with ROOT, depth first. Convert all | |
1264 | trampolines and call expressions. On the way back up, determine if | |
1265 | a nested function actually uses its static chain; if not, remember that. */ | |
1266 | ||
1267 | static void | |
1268 | convert_all_function_calls (struct nesting_info *root) | |
1269 | { | |
1270 | do | |
1271 | { | |
1272 | if (root->inner) | |
1273 | convert_all_function_calls (root->inner); | |
1274 | ||
1275 | walk_function (convert_tramp_reference, root); | |
1276 | walk_function (convert_call_expr, root); | |
1277 | ||
1278 | /* If the function does not use a static chain, then remember that. */ | |
1279 | if (root->outer && !root->chain_decl && !root->chain_field) | |
1280 | DECL_NO_STATIC_CHAIN (root->context) = 1; | |
1281 | else | |
1e128c5f | 1282 | gcc_assert (!DECL_NO_STATIC_CHAIN (root->context)); |
6de9cd9a DN |
1283 | |
1284 | root = root->next; | |
1285 | } | |
1286 | while (root); | |
1287 | } | |
1288 | ||
1289 | /* Do "everything else" to clean up or complete state collected by the | |
1290 | various walking passes -- lay out the types and decls, generate code | |
1291 | to initialize the frame decl, store critical expressions in the | |
1292 | struct function for rtl to find. */ | |
1293 | ||
1294 | static void | |
1295 | finalize_nesting_tree_1 (struct nesting_info *root) | |
1296 | { | |
1297 | tree stmt_list = NULL; | |
1298 | tree context = root->context; | |
1299 | struct function *sf; | |
8f235343 | 1300 | struct cgraph_node *node; |
6de9cd9a DN |
1301 | |
1302 | /* If we created a non-local frame type or decl, we need to lay them | |
1303 | out at this time. */ | |
1304 | if (root->frame_type) | |
1305 | { | |
1306 | layout_type (root->frame_type); | |
1307 | layout_decl (root->frame_decl, 0); | |
1308 | } | |
1309 | ||
1310 | /* If any parameters were referenced non-locally, then we need to | |
1311 | insert a copy. Likewise, if any variables were referenced by | |
1312 | pointer, we need to initialize the address. */ | |
1313 | if (root->any_parm_remapped) | |
1314 | { | |
1315 | tree p; | |
1316 | for (p = DECL_ARGUMENTS (context); p ; p = TREE_CHAIN (p)) | |
1317 | { | |
1318 | tree field, x, y; | |
1319 | ||
1320 | field = lookup_field_for_decl (root, p, NO_INSERT); | |
1321 | if (!field) | |
1322 | continue; | |
1323 | ||
1324 | if (use_pointer_in_frame (p)) | |
1325 | x = build_addr (p); | |
1326 | else | |
1327 | x = p; | |
1328 | ||
1329 | y = build (COMPONENT_REF, TREE_TYPE (field), | |
44de5aeb | 1330 | root->frame_decl, field, NULL_TREE); |
6de9cd9a DN |
1331 | x = build (MODIFY_EXPR, TREE_TYPE (field), y, x); |
1332 | append_to_statement_list (x, &stmt_list); | |
1333 | } | |
1334 | } | |
1335 | ||
1336 | /* If a chain_field was created, then it needs to be initialized | |
1337 | from chain_decl. */ | |
1338 | if (root->chain_field) | |
1339 | { | |
44de5aeb RK |
1340 | tree x = build (COMPONENT_REF, TREE_TYPE (root->chain_field), |
1341 | root->frame_decl, root->chain_field, NULL_TREE); | |
6de9cd9a DN |
1342 | x = build (MODIFY_EXPR, TREE_TYPE (x), x, get_chain_decl (root)); |
1343 | append_to_statement_list (x, &stmt_list); | |
1344 | } | |
1345 | ||
1346 | /* If trampolines were created, then we need to initialize them. */ | |
1347 | if (root->any_tramp_created) | |
1348 | { | |
1349 | struct nesting_info *i; | |
1350 | for (i = root->inner; i ; i = i->next) | |
1351 | { | |
1352 | tree arg, x, field; | |
1353 | ||
1354 | field = lookup_tramp_for_decl (root, i->context, NO_INSERT); | |
1355 | if (!field) | |
1356 | continue; | |
1357 | ||
1358 | if (DECL_NO_STATIC_CHAIN (i->context)) | |
1359 | x = null_pointer_node; | |
1360 | else | |
1361 | x = build_addr (root->frame_decl); | |
1362 | arg = tree_cons (NULL, x, NULL); | |
1363 | ||
1364 | x = build_addr (i->context); | |
1365 | arg = tree_cons (NULL, x, arg); | |
1366 | ||
1367 | x = build (COMPONENT_REF, TREE_TYPE (field), | |
44de5aeb | 1368 | root->frame_decl, field, NULL_TREE); |
6de9cd9a DN |
1369 | x = build_addr (x); |
1370 | arg = tree_cons (NULL, x, arg); | |
1371 | ||
1372 | x = implicit_built_in_decls[BUILT_IN_INIT_TRAMPOLINE]; | |
1373 | x = build_function_call_expr (x, arg); | |
1374 | ||
1375 | append_to_statement_list (x, &stmt_list); | |
1376 | } | |
1377 | } | |
1378 | ||
1379 | /* If we created initialization statements, insert them. */ | |
1380 | if (stmt_list) | |
1381 | { | |
1382 | annotate_all_with_locus (&stmt_list, | |
1383 | DECL_SOURCE_LOCATION (context)); | |
1384 | append_to_statement_list (BIND_EXPR_BODY (DECL_SAVED_TREE (context)), | |
1385 | &stmt_list); | |
1386 | BIND_EXPR_BODY (DECL_SAVED_TREE (context)) = stmt_list; | |
1387 | } | |
1388 | ||
1389 | /* If a chain_decl was created, then it needs to be registered with | |
1390 | struct function so that it gets initialized from the static chain | |
1391 | register at the beginning of the function. */ | |
1392 | sf = DECL_STRUCT_FUNCTION (root->context); | |
1393 | sf->static_chain_decl = root->chain_decl; | |
1394 | ||
1395 | /* Similarly for the non-local goto save area. */ | |
1396 | if (root->nl_goto_field) | |
1397 | { | |
1398 | sf->nonlocal_goto_save_area | |
1399 | = get_frame_field (root, context, root->nl_goto_field, NULL); | |
1400 | sf->has_nonlocal_label = 1; | |
1401 | } | |
1402 | ||
1ea7e6ad | 1403 | /* Make sure all new local variables get inserted into the |
6de9cd9a DN |
1404 | proper BIND_EXPR. */ |
1405 | if (root->new_local_var_chain) | |
1406 | declare_tmp_vars (root->new_local_var_chain, | |
1407 | DECL_SAVED_TREE (root->context)); | |
1408 | ||
1409 | /* Dump the translated tree function. */ | |
1410 | dump_function (TDI_nested, root->context); | |
8f235343 JH |
1411 | node = cgraph_node (root->context); |
1412 | ||
1413 | /* For nested functions update the cgraph to reflect unnesting. | |
1414 | We also delay finalizing of these functions up to this point. */ | |
1415 | if (node->origin) | |
1416 | { | |
1417 | cgraph_unnest_node (cgraph_node (root->context)); | |
1418 | cgraph_finalize_function (root->context, true); | |
1419 | } | |
6de9cd9a DN |
1420 | } |
1421 | ||
1422 | static void | |
1423 | finalize_nesting_tree (struct nesting_info *root) | |
1424 | { | |
1425 | do | |
1426 | { | |
1427 | if (root->inner) | |
1428 | finalize_nesting_tree (root->inner); | |
1429 | finalize_nesting_tree_1 (root); | |
1430 | root = root->next; | |
1431 | } | |
1432 | while (root); | |
1433 | } | |
1434 | ||
1435 | /* Free the data structures allocated during this pass. */ | |
1436 | ||
1437 | static void | |
1438 | free_nesting_tree (struct nesting_info *root) | |
1439 | { | |
1440 | struct nesting_info *next; | |
1441 | do | |
1442 | { | |
1443 | if (root->inner) | |
1444 | free_nesting_tree (root->inner); | |
1445 | htab_delete (root->var_map); | |
1446 | next = root->next; | |
1447 | free (root); | |
1448 | root = next; | |
1449 | } | |
1450 | while (root); | |
1451 | } | |
1452 | ||
1453 | /* Main entry point for this pass. Process FNDECL and all of its nested | |
1454 | subroutines and turn them into something less tightly bound. */ | |
1455 | ||
1456 | void | |
1457 | lower_nested_functions (tree fndecl) | |
1458 | { | |
1459 | struct nesting_info *root; | |
1460 | struct cgraph_node *cgn; | |
1461 | ||
1462 | /* If there are no nested functions, there's nothing to do. */ | |
1463 | cgn = cgraph_node (fndecl); | |
1464 | if (!cgn->nested) | |
1465 | return; | |
1466 | ||
1467 | root = create_nesting_tree (cgn); | |
1468 | walk_all_functions (convert_nonlocal_reference, root); | |
1469 | walk_all_functions (convert_local_reference, root); | |
1470 | walk_all_functions (convert_nl_goto_reference, root); | |
1471 | walk_all_functions (convert_nl_goto_receiver, root); | |
1472 | convert_all_function_calls (root); | |
1473 | finalize_nesting_tree (root); | |
1474 | free_nesting_tree (root); | |
1475 | } | |
1476 | ||
1477 | #include "gt-tree-nested.h" |