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4ee9c684 | 1 | /* Nested function decomposition for trees. |
2 | Copyright (C) 2004 Free Software Foundation, Inc. | |
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" | |
88bce636 | 31 | #include "tree-gimple.h" |
4ee9c684 | 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 | |
58 | structure herein called the "nonlocal frame struct". The incomming | |
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 | ||
135 | #if defined ENABLE_CHECKING | |
c5bfd674 | 136 | /* If the type is of variable size or a type which must be created by the |
4ee9c684 | 137 | frontend, something is wrong. Note that we explicitly allow |
138 | incomplete types here, since we create them ourselves here. */ | |
c5bfd674 | 139 | if (TREE_ADDRESSABLE (type) |
140 | || (TYPE_SIZE_UNIT (type) | |
141 | && TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST)) | |
4ee9c684 | 142 | abort (); |
143 | #endif | |
144 | ||
145 | tmp_var = create_tmp_var_raw (type, prefix); | |
146 | DECL_CONTEXT (tmp_var) = info->context; | |
147 | TREE_CHAIN (tmp_var) = info->new_local_var_chain; | |
60f65a0a | 148 | DECL_SEEN_IN_BIND_EXPR_P (tmp_var) = 1; |
4ee9c684 | 149 | info->new_local_var_chain = tmp_var; |
150 | ||
151 | return tmp_var; | |
152 | } | |
153 | ||
154 | /* Take the address of EXP. Mark it for addressability as necessary. */ | |
155 | ||
156 | static tree | |
157 | build_addr (tree exp) | |
158 | { | |
159 | tree base = exp; | |
6374121b | 160 | |
9124cf12 | 161 | while (TREE_CODE (base) == REALPART_EXPR || TREE_CODE (base) == IMAGPART_EXPR |
162 | || handled_component_p (base)) | |
4ee9c684 | 163 | base = TREE_OPERAND (base, 0); |
6374121b | 164 | |
4ee9c684 | 165 | if (DECL_P (base)) |
166 | TREE_ADDRESSABLE (base) = 1; | |
167 | ||
168 | return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp); | |
169 | } | |
170 | ||
171 | /* Insert FIELD into TYPE, sorted by alignment requirements. */ | |
172 | ||
173 | static void | |
174 | insert_field_into_struct (tree type, tree field) | |
175 | { | |
176 | tree *p; | |
177 | ||
178 | DECL_CONTEXT (field) = type; | |
179 | ||
180 | for (p = &TYPE_FIELDS (type); *p ; p = &TREE_CHAIN (*p)) | |
181 | if (DECL_ALIGN (field) >= DECL_ALIGN (*p)) | |
182 | break; | |
183 | ||
184 | TREE_CHAIN (field) = *p; | |
185 | *p = field; | |
186 | } | |
187 | ||
188 | /* Build or return the RECORD_TYPE that describes the frame state that is | |
189 | shared between INFO->CONTEXT and its nested functions. This record will | |
190 | not be complete until finalize_nesting_tree; up until that point we'll | |
191 | be adding fields as necessary. | |
192 | ||
193 | We also build the DECL that represents this frame in the function. */ | |
194 | ||
195 | static tree | |
196 | get_frame_type (struct nesting_info *info) | |
197 | { | |
198 | tree type = info->frame_type; | |
199 | if (!type) | |
200 | { | |
201 | char *name; | |
202 | ||
203 | type = make_node (RECORD_TYPE); | |
204 | ||
205 | name = concat ("FRAME.", | |
206 | IDENTIFIER_POINTER (DECL_NAME (info->context)), | |
207 | NULL); | |
208 | TYPE_NAME (type) = get_identifier (name); | |
209 | free (name); | |
210 | ||
211 | info->frame_type = type; | |
212 | info->frame_decl = create_tmp_var_for (info, type, "FRAME"); | |
213 | } | |
214 | return type; | |
215 | } | |
216 | ||
217 | /* Return true if DECL should be referenced by pointer in the non-local | |
218 | frame structure. */ | |
219 | ||
220 | static bool | |
221 | use_pointer_in_frame (tree decl) | |
222 | { | |
223 | if (TREE_CODE (decl) == PARM_DECL) | |
224 | { | |
225 | /* It's illegal to copy TREE_ADDRESSABLE, impossible to copy variable | |
226 | sized decls, and inefficient to copy large aggregates. Don't bother | |
227 | moving anything but scalar variables. */ | |
228 | return AGGREGATE_TYPE_P (TREE_TYPE (decl)); | |
229 | } | |
230 | else | |
231 | { | |
232 | /* Variable sized types make things "interesting" in the frame. */ | |
233 | return DECL_SIZE (decl) == NULL || !TREE_CONSTANT (DECL_SIZE (decl)); | |
234 | } | |
235 | } | |
236 | ||
237 | /* Given DECL, a non-locally accessed variable, find or create a field | |
238 | in the non-local frame structure for the given nesting context. */ | |
239 | ||
240 | static tree | |
241 | lookup_field_for_decl (struct nesting_info *info, tree decl, | |
242 | enum insert_option insert) | |
243 | { | |
244 | struct var_map_elt *elt, dummy; | |
245 | void **slot; | |
246 | tree field; | |
247 | ||
248 | dummy.old = decl; | |
249 | slot = htab_find_slot (info->var_map, &dummy, insert); | |
250 | if (!slot) | |
251 | { | |
252 | if (insert == INSERT) | |
253 | abort (); | |
254 | return NULL; | |
255 | } | |
256 | elt = *slot; | |
257 | ||
258 | if (!elt && insert == INSERT) | |
259 | { | |
260 | field = make_node (FIELD_DECL); | |
261 | DECL_NAME (field) = DECL_NAME (decl); | |
262 | ||
263 | if (use_pointer_in_frame (decl)) | |
264 | { | |
265 | TREE_TYPE (field) = build_pointer_type (TREE_TYPE (decl)); | |
266 | DECL_ALIGN (field) = TYPE_ALIGN (TREE_TYPE (field)); | |
267 | DECL_NONADDRESSABLE_P (field) = 1; | |
268 | } | |
269 | else | |
270 | { | |
271 | TREE_TYPE (field) = TREE_TYPE (decl); | |
272 | DECL_SOURCE_LOCATION (field) = DECL_SOURCE_LOCATION (decl); | |
273 | DECL_ALIGN (field) = DECL_ALIGN (decl); | |
274 | DECL_USER_ALIGN (field) = DECL_USER_ALIGN (decl); | |
275 | TREE_ADDRESSABLE (field) = TREE_ADDRESSABLE (decl); | |
276 | DECL_NONADDRESSABLE_P (field) = !TREE_ADDRESSABLE (decl); | |
277 | TREE_THIS_VOLATILE (field) = TREE_THIS_VOLATILE (decl); | |
278 | } | |
279 | ||
280 | insert_field_into_struct (get_frame_type (info), field); | |
281 | ||
282 | elt = xmalloc (sizeof (*elt)); | |
283 | elt->old = decl; | |
284 | elt->new = field; | |
285 | *slot = elt; | |
286 | ||
287 | if (TREE_CODE (decl) == PARM_DECL) | |
288 | info->any_parm_remapped = true; | |
289 | } | |
290 | else | |
291 | field = elt ? elt->new : NULL; | |
292 | ||
293 | return field; | |
294 | } | |
295 | ||
296 | /* Build or return the variable that holds the static chain within | |
297 | INFO->CONTEXT. This variable may only be used within INFO->CONTEXT. */ | |
298 | ||
299 | static tree | |
300 | get_chain_decl (struct nesting_info *info) | |
301 | { | |
302 | tree decl = info->chain_decl; | |
303 | if (!decl) | |
304 | { | |
305 | tree type; | |
306 | ||
307 | type = get_frame_type (info->outer); | |
308 | type = build_pointer_type (type); | |
309 | ||
310 | /* Note that this variable is *not* entered into any BIND_EXPR; | |
311 | the construction of this variable is handled specially in | |
3efaa21f | 312 | expand_function_start and initialize_inlined_parameters. |
313 | Note also that it's represented as a parameter. This is more | |
314 | close to the truth, since the initial value does come from | |
315 | the caller. */ | |
316 | decl = build_decl (PARM_DECL, create_tmp_var_name ("CHAIN"), type); | |
317 | DECL_ARTIFICIAL (decl) = 1; | |
318 | DECL_IGNORED_P (decl) = 1; | |
319 | TREE_USED (decl) = 1; | |
4ee9c684 | 320 | DECL_CONTEXT (decl) = info->context; |
3efaa21f | 321 | DECL_ARG_TYPE (decl) = type; |
4ee9c684 | 322 | |
323 | /* Tell tree-inline.c that we never write to this variable, so | |
324 | it can copy-prop the replacement value immediately. */ | |
325 | TREE_READONLY (decl) = 1; | |
326 | ||
327 | info->chain_decl = decl; | |
328 | } | |
329 | return decl; | |
330 | } | |
331 | ||
332 | /* Build or return the field within the non-local frame state that holds | |
333 | the static chain for INFO->CONTEXT. This is the way to walk back up | |
334 | multiple nesting levels. */ | |
335 | ||
336 | static tree | |
337 | get_chain_field (struct nesting_info *info) | |
338 | { | |
339 | tree field = info->chain_field; | |
340 | if (!field) | |
341 | { | |
342 | tree type = build_pointer_type (get_frame_type (info->outer)); | |
343 | ||
344 | field = make_node (FIELD_DECL); | |
345 | DECL_NAME (field) = get_identifier ("__chain"); | |
346 | TREE_TYPE (field) = type; | |
347 | DECL_ALIGN (field) = TYPE_ALIGN (type); | |
348 | DECL_NONADDRESSABLE_P (field) = 1; | |
349 | ||
350 | insert_field_into_struct (get_frame_type (info), field); | |
351 | ||
352 | info->chain_field = field; | |
353 | } | |
354 | return field; | |
355 | } | |
356 | ||
357 | /* Copy EXP into a temporary. Allocate the temporary in the context of | |
358 | INFO and insert the initialization statement before TSI. */ | |
359 | ||
360 | static tree | |
361 | init_tmp_var (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi) | |
362 | { | |
363 | tree t, stmt; | |
364 | ||
365 | t = create_tmp_var_for (info, TREE_TYPE (exp), NULL); | |
366 | stmt = build (MODIFY_EXPR, TREE_TYPE (t), t, exp); | |
367 | SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi))); | |
368 | tsi_link_before (tsi, stmt, TSI_SAME_STMT); | |
369 | ||
370 | return t; | |
371 | } | |
372 | ||
373 | /* Similarly, but only do so to force EXP to satisfy is_gimple_val. */ | |
374 | ||
375 | static tree | |
83e2a11b | 376 | tsi_gimplify_val (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi) |
4ee9c684 | 377 | { |
378 | if (is_gimple_val (exp)) | |
379 | return exp; | |
380 | else | |
381 | return init_tmp_var (info, exp, tsi); | |
382 | } | |
383 | ||
384 | /* Build or return the type used to represent a nested function trampoline. */ | |
385 | ||
386 | static GTY(()) tree trampoline_type; | |
387 | ||
388 | static tree | |
389 | get_trampoline_type (void) | |
390 | { | |
391 | tree record, t; | |
392 | unsigned align, size; | |
393 | ||
394 | if (trampoline_type) | |
395 | return trampoline_type; | |
396 | ||
397 | align = TRAMPOLINE_ALIGNMENT; | |
398 | size = TRAMPOLINE_SIZE; | |
399 | ||
400 | /* If we won't be able to guarantee alignment simply via TYPE_ALIGN, | |
401 | then allocate extra space so that we can do dynamic alignment. */ | |
402 | if (align > STACK_BOUNDARY) | |
403 | { | |
404 | size += ((align/BITS_PER_UNIT) - 1) & -(STACK_BOUNDARY/BITS_PER_UNIT); | |
405 | align = STACK_BOUNDARY; | |
406 | } | |
407 | ||
408 | t = build_index_type (build_int_2 (size - 1, 0)); | |
409 | t = build_array_type (char_type_node, t); | |
410 | t = build_decl (FIELD_DECL, get_identifier ("__data"), t); | |
411 | DECL_ALIGN (t) = align; | |
412 | DECL_USER_ALIGN (t) = 1; | |
413 | ||
414 | record = make_node (RECORD_TYPE); | |
415 | TYPE_NAME (record) = get_identifier ("__builtin_trampoline"); | |
416 | TYPE_FIELDS (record) = t; | |
417 | layout_type (record); | |
418 | ||
419 | return record; | |
420 | } | |
421 | ||
422 | /* Given DECL, a nested function, find or create a field in the non-local | |
423 | frame structure for a trampoline for this function. */ | |
424 | ||
425 | static tree | |
426 | lookup_tramp_for_decl (struct nesting_info *info, tree decl, | |
427 | enum insert_option insert) | |
428 | { | |
429 | struct var_map_elt *elt, dummy; | |
430 | void **slot; | |
431 | tree field; | |
432 | ||
433 | dummy.old = decl; | |
434 | slot = htab_find_slot (info->var_map, &dummy, insert); | |
435 | if (!slot) | |
436 | { | |
437 | if (insert == INSERT) | |
438 | abort (); | |
439 | return NULL; | |
440 | } | |
441 | elt = *slot; | |
442 | ||
443 | if (!elt && insert == INSERT) | |
444 | { | |
445 | field = make_node (FIELD_DECL); | |
446 | DECL_NAME (field) = DECL_NAME (decl); | |
447 | TREE_TYPE (field) = get_trampoline_type (); | |
448 | TREE_ADDRESSABLE (field) = 1; | |
449 | ||
450 | insert_field_into_struct (get_frame_type (info), field); | |
451 | ||
452 | elt = xmalloc (sizeof (*elt)); | |
453 | elt->old = decl; | |
454 | elt->new = field; | |
455 | *slot = elt; | |
456 | ||
457 | info->any_tramp_created = true; | |
458 | } | |
459 | else | |
460 | field = elt ? elt->new : NULL; | |
461 | ||
462 | return field; | |
463 | } | |
464 | ||
465 | /* Build or return the field within the non-local frame state that holds | |
466 | the non-local goto "jmp_buf". The buffer itself is maintained by the | |
467 | rtl middle-end as dynamic stack space is allocated. */ | |
468 | ||
469 | static tree | |
470 | get_nl_goto_field (struct nesting_info *info) | |
471 | { | |
472 | tree field = info->nl_goto_field; | |
473 | if (!field) | |
474 | { | |
475 | unsigned size; | |
476 | tree type; | |
477 | ||
478 | /* For __builtin_nonlocal_goto, we need N words. The first is the | |
479 | frame pointer, the rest is for the target's stack pointer save | |
365db11e | 480 | area. The number of words is controlled by STACK_SAVEAREA_MODE; |
4ee9c684 | 481 | not the best interface, but it'll do for now. */ |
482 | if (Pmode == ptr_mode) | |
483 | type = ptr_type_node; | |
484 | else | |
485 | type = lang_hooks.types.type_for_mode (Pmode, 1); | |
486 | ||
487 | size = GET_MODE_SIZE (STACK_SAVEAREA_MODE (SAVE_NONLOCAL)); | |
488 | size = size / GET_MODE_SIZE (Pmode); | |
489 | size = size + 1; | |
490 | ||
491 | type = build_array_type (type, build_index_type (build_int_2 (size, 0))); | |
492 | ||
493 | field = make_node (FIELD_DECL); | |
494 | DECL_NAME (field) = get_identifier ("__nl_goto_buf"); | |
495 | TREE_TYPE (field) = type; | |
496 | DECL_ALIGN (field) = TYPE_ALIGN (type); | |
497 | TREE_ADDRESSABLE (field) = 1; | |
498 | ||
499 | insert_field_into_struct (get_frame_type (info), field); | |
500 | ||
501 | info->nl_goto_field = field; | |
502 | } | |
503 | ||
504 | return field; | |
505 | } | |
506 | \f | |
507 | /* Convenience routines to walk all statements of a gimple function. | |
508 | ||
509 | For each statement, we invoke CALLBACK via walk_tree. The passed | |
510 | data is a walk_stmt_info structure. Of note here is a TSI that | |
511 | points to the current statement being walked. The VAL_ONLY flag | |
512 | that indicates whether the *TP being examined may be replaced | |
513 | with something that matches is_gimple_val (if true) or something | |
514 | slightly more complicated (if false). "Something" technically | |
515 | means the common subset of is_gimple_lvalue and is_gimple_rhs, | |
516 | but we never try to form anything more complicated than that, so | |
517 | we don't bother checking. */ | |
518 | ||
519 | struct walk_stmt_info | |
520 | { | |
521 | walk_tree_fn callback; | |
522 | tree_stmt_iterator tsi; | |
523 | struct nesting_info *info; | |
524 | bool val_only; | |
525 | }; | |
526 | ||
527 | /* A subroutine of walk_function. Iterate over all sub-statements of *TP. */ | |
528 | ||
529 | static void | |
530 | walk_stmts (struct walk_stmt_info *wi, tree *tp) | |
531 | { | |
532 | tree t = *tp; | |
533 | if (!t) | |
534 | return; | |
535 | ||
536 | switch (TREE_CODE (t)) | |
537 | { | |
538 | case STATEMENT_LIST: | |
539 | { | |
540 | tree_stmt_iterator i; | |
541 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
542 | { | |
543 | wi->tsi = i; | |
544 | walk_stmts (wi, tsi_stmt_ptr (i)); | |
545 | } | |
546 | } | |
547 | break; | |
548 | ||
549 | case COND_EXPR: | |
550 | walk_tree (&COND_EXPR_COND (t), wi->callback, wi, NULL); | |
551 | walk_stmts (wi, &COND_EXPR_THEN (t)); | |
552 | walk_stmts (wi, &COND_EXPR_ELSE (t)); | |
553 | break; | |
554 | case CATCH_EXPR: | |
555 | walk_stmts (wi, &CATCH_BODY (t)); | |
6374121b | 556 | break; |
4ee9c684 | 557 | case EH_FILTER_EXPR: |
558 | walk_stmts (wi, &EH_FILTER_FAILURE (t)); | |
559 | break; | |
560 | case TRY_CATCH_EXPR: | |
561 | case TRY_FINALLY_EXPR: | |
562 | walk_stmts (wi, &TREE_OPERAND (t, 0)); | |
563 | walk_stmts (wi, &TREE_OPERAND (t, 1)); | |
564 | break; | |
565 | case BIND_EXPR: | |
566 | walk_stmts (wi, &BIND_EXPR_BODY (t)); | |
567 | break; | |
568 | ||
569 | case RETURN_EXPR: | |
570 | walk_stmts (wi, &TREE_OPERAND (t, 0)); | |
571 | break; | |
572 | ||
573 | case MODIFY_EXPR: | |
574 | /* The immediate arguments of a MODIFY_EXPR may use COMPONENT_REF. */ | |
575 | wi->val_only = false; | |
576 | walk_tree (&TREE_OPERAND (t, 0), wi->callback, wi, NULL); | |
577 | wi->val_only = false; | |
578 | walk_tree (&TREE_OPERAND (t, 1), wi->callback, wi, NULL); | |
579 | wi->val_only = true; | |
580 | break; | |
581 | ||
582 | default: | |
583 | wi->val_only = true; | |
584 | walk_tree (tp, wi->callback, wi, NULL); | |
585 | break; | |
586 | } | |
587 | } | |
588 | ||
589 | /* Invoke CALLBACK on all statements of INFO->CONTEXT. */ | |
590 | ||
591 | static void | |
592 | walk_function (walk_tree_fn callback, struct nesting_info *info) | |
593 | { | |
594 | struct walk_stmt_info wi; | |
595 | ||
596 | memset (&wi, 0, sizeof (wi)); | |
597 | wi.callback = callback; | |
598 | wi.info = info; | |
599 | wi.val_only = true; | |
600 | ||
601 | walk_stmts (&wi, &DECL_SAVED_TREE (info->context)); | |
602 | } | |
603 | ||
604 | /* Similarly for ROOT and all functions nested underneath, depth first. */ | |
605 | ||
606 | static void | |
607 | walk_all_functions (walk_tree_fn callback, struct nesting_info *root) | |
608 | { | |
609 | do | |
610 | { | |
611 | if (root->inner) | |
612 | walk_all_functions (callback, root->inner); | |
613 | walk_function (callback, root); | |
614 | root = root->next; | |
615 | } | |
616 | while (root); | |
617 | } | |
618 | ||
619 | \f | |
620 | /* Construct our local datastructure describing the function nesting | |
621 | tree rooted by CGN. */ | |
622 | ||
623 | static struct nesting_info * | |
624 | create_nesting_tree (struct cgraph_node *cgn) | |
625 | { | |
626 | struct nesting_info *info = xcalloc (1, sizeof (*info)); | |
627 | info->var_map = htab_create (7, var_map_hash, var_map_eq, free); | |
628 | info->context = cgn->decl; | |
629 | ||
630 | for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested) | |
631 | { | |
632 | struct nesting_info *sub = create_nesting_tree (cgn); | |
633 | sub->outer = info; | |
634 | sub->next = info->inner; | |
635 | info->inner = sub; | |
636 | } | |
637 | ||
638 | return info; | |
639 | } | |
640 | ||
641 | /* Return an expression computing the static chain for TARGET_CONTEXT | |
642 | from INFO->CONTEXT. Insert any necessary computations before TSI. */ | |
643 | ||
644 | static tree | |
645 | get_static_chain (struct nesting_info *info, tree target_context, | |
646 | tree_stmt_iterator *tsi) | |
647 | { | |
648 | struct nesting_info *i; | |
649 | tree x; | |
650 | ||
651 | if (info->context == target_context) | |
652 | { | |
653 | x = build_addr (info->frame_decl); | |
654 | } | |
655 | else | |
656 | { | |
657 | x = get_chain_decl (info); | |
658 | ||
659 | for (i = info->outer; i->context != target_context; i = i->outer) | |
660 | { | |
661 | tree field = get_chain_field (i); | |
662 | ||
663 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
6374121b | 664 | x = build (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE); |
4ee9c684 | 665 | x = init_tmp_var (info, x, tsi); |
666 | } | |
667 | } | |
668 | ||
669 | return x; | |
670 | } | |
671 | ||
672 | /* Return an expression referencing FIELD from TARGET_CONTEXT's non-local | |
673 | frame as seen from INFO->CONTEXT. Insert any necessary computations | |
674 | before TSI. */ | |
675 | ||
676 | static tree | |
677 | get_frame_field (struct nesting_info *info, tree target_context, | |
678 | tree field, tree_stmt_iterator *tsi) | |
679 | { | |
680 | struct nesting_info *i; | |
681 | tree x; | |
682 | ||
683 | if (info->context == target_context) | |
684 | { | |
685 | /* Make sure frame_decl gets created. */ | |
686 | (void) get_frame_type (info); | |
687 | x = info->frame_decl; | |
688 | } | |
689 | else | |
690 | { | |
691 | x = get_chain_decl (info); | |
692 | ||
693 | for (i = info->outer; i->context != target_context; i = i->outer) | |
694 | { | |
695 | tree field = get_chain_field (i); | |
696 | ||
697 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
6374121b | 698 | x = build (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE); |
4ee9c684 | 699 | x = init_tmp_var (info, x, tsi); |
700 | } | |
701 | ||
702 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
703 | } | |
704 | ||
6374121b | 705 | x = build (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE); |
4ee9c684 | 706 | return x; |
707 | } | |
708 | ||
709 | /* Called via walk_function+walk_tree, rewrite all references to VAR | |
710 | and PARM_DECLs that belong to outer functions. | |
711 | ||
712 | The rewrite will involve some number of structure accesses back up | |
713 | the static chain. E.g. for a variable FOO up one nesting level it'll | |
714 | be CHAIN->FOO. For two levels it'll be CHAIN->__chain->FOO. Further | |
715 | indirections apply to decls for which use_pointer_in_frame is true. */ | |
716 | ||
717 | static tree | |
718 | convert_nonlocal_reference (tree *tp, int *walk_subtrees, void *data) | |
719 | { | |
720 | struct walk_stmt_info *wi = data; | |
721 | struct nesting_info *info = wi->info; | |
722 | tree t = *tp; | |
723 | ||
724 | *walk_subtrees = 0; | |
725 | switch (TREE_CODE (t)) | |
726 | { | |
727 | case VAR_DECL: | |
728 | /* Non-automatic variables are never processed. */ | |
729 | if (TREE_STATIC (t) || DECL_EXTERNAL (t)) | |
730 | break; | |
731 | /* FALLTHRU */ | |
732 | ||
733 | case PARM_DECL: | |
734 | if (decl_function_context (t) != info->context) | |
735 | { | |
736 | tree target_context = decl_function_context (t); | |
737 | struct nesting_info *i; | |
738 | tree x; | |
739 | ||
740 | for (i = info->outer; i->context != target_context; i = i->outer) | |
741 | continue; | |
742 | x = lookup_field_for_decl (i, t, INSERT); | |
743 | x = get_frame_field (info, target_context, x, &wi->tsi); | |
744 | if (use_pointer_in_frame (t)) | |
745 | { | |
746 | x = init_tmp_var (info, x, &wi->tsi); | |
747 | x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x); | |
748 | } | |
749 | if (wi->val_only) | |
750 | x = init_tmp_var (info, x, &wi->tsi); | |
751 | ||
752 | *tp = x; | |
753 | } | |
754 | break; | |
755 | ||
756 | case GOTO_EXPR: | |
757 | /* Don't walk non-local gotos for now. */ | |
758 | if (TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL) | |
759 | { | |
760 | *walk_subtrees = 1; | |
761 | wi->val_only = true; | |
762 | } | |
763 | break; | |
764 | ||
765 | case LABEL_DECL: | |
766 | /* We're taking the address of a label from a parent function, but | |
767 | this is not itself a non-local goto. Mark the label such that it | |
768 | will not be deleted, much as we would with a label address in | |
769 | static storage. */ | |
770 | if (decl_function_context (t) != info->context) | |
771 | FORCED_LABEL (t) = 1; | |
772 | break; | |
773 | ||
774 | case ADDR_EXPR: | |
775 | { | |
776 | bool save_val_only = wi->val_only; | |
777 | tree save_sub = TREE_OPERAND (t, 0); | |
778 | ||
779 | wi->val_only = false; | |
780 | walk_tree (&TREE_OPERAND (t, 0), convert_nonlocal_reference, wi, NULL); | |
781 | wi->val_only = true; | |
782 | ||
783 | if (save_sub != TREE_OPERAND (t, 0)) | |
784 | { | |
785 | /* If we changed anything, then TREE_INVARIANT is be wrong, | |
786 | since we're no longer directly referencing a decl. */ | |
787 | TREE_INVARIANT (t) = 0; | |
788 | ||
789 | /* If the callback converted the address argument in a context | |
790 | where we only accept variables (and min_invariant, presumably), | |
791 | then compute the address into a temporary. */ | |
792 | if (save_val_only) | |
83e2a11b | 793 | *tp = tsi_gimplify_val (wi->info, t, &wi->tsi); |
4ee9c684 | 794 | } |
795 | } | |
796 | break; | |
797 | ||
4ee9c684 | 798 | case REALPART_EXPR: |
799 | case IMAGPART_EXPR: | |
9124cf12 | 800 | case COMPONENT_REF: |
4ee9c684 | 801 | case ARRAY_REF: |
6374121b | 802 | case ARRAY_RANGE_REF: |
4ee9c684 | 803 | case BIT_FIELD_REF: |
c5bfd674 | 804 | /* Go down this entire nest and just look at the final prefix and |
805 | anything that describes the references. Otherwise, we lose track | |
806 | of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value. */ | |
4ee9c684 | 807 | wi->val_only = true; |
c5bfd674 | 808 | for (; handled_component_p (t) |
809 | || TREE_CODE (t) == REALPART_EXPR || TREE_CODE (t) == IMAGPART_EXPR; | |
810 | tp = &TREE_OPERAND (t, 0), t = *tp) | |
811 | { | |
812 | if (TREE_CODE (t) == COMPONENT_REF) | |
813 | walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi, | |
814 | NULL); | |
815 | else if (TREE_CODE (t) == ARRAY_REF | |
816 | || TREE_CODE (t) == ARRAY_RANGE_REF) | |
817 | { | |
818 | walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi, | |
819 | NULL); | |
820 | walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi, | |
821 | NULL); | |
822 | walk_tree (&TREE_OPERAND (t, 3), convert_nonlocal_reference, wi, | |
823 | NULL); | |
824 | } | |
825 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
826 | { | |
827 | walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi, | |
828 | NULL); | |
829 | walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi, | |
830 | NULL); | |
831 | } | |
832 | } | |
833 | wi->val_only = false; | |
834 | walk_tree (tp, convert_nonlocal_reference, wi, NULL); | |
4ee9c684 | 835 | break; |
836 | ||
837 | default: | |
838 | if (!DECL_P (t) && !TYPE_P (t)) | |
839 | { | |
840 | *walk_subtrees = 1; | |
841 | wi->val_only = true; | |
842 | } | |
843 | break; | |
844 | } | |
845 | ||
846 | return NULL_TREE; | |
847 | } | |
848 | ||
849 | /* Called via walk_function+walk_tree, rewrite all references to VAR | |
850 | and PARM_DECLs that were referenced by inner nested functions. | |
851 | The rewrite will be a structure reference to the local frame variable. */ | |
852 | ||
853 | static tree | |
854 | convert_local_reference (tree *tp, int *walk_subtrees, void *data) | |
855 | { | |
856 | struct walk_stmt_info *wi = data; | |
857 | struct nesting_info *info = wi->info; | |
858 | tree t = *tp, field, x, y; | |
859 | ||
860 | switch (TREE_CODE (t)) | |
861 | { | |
862 | case VAR_DECL: | |
863 | /* Non-automatic variables are never processed. */ | |
864 | if (TREE_STATIC (t) || DECL_EXTERNAL (t)) | |
865 | break; | |
866 | /* FALLTHRU */ | |
867 | ||
868 | case PARM_DECL: | |
869 | if (decl_function_context (t) == info->context) | |
870 | { | |
871 | /* If we copied a pointer to the frame, then the original decl | |
872 | is used unchanged in the parent function. */ | |
873 | if (use_pointer_in_frame (t)) | |
874 | break; | |
875 | ||
876 | /* No need to transform anything if no child references the | |
877 | variable. */ | |
878 | field = lookup_field_for_decl (info, t, NO_INSERT); | |
879 | if (!field) | |
880 | break; | |
881 | ||
882 | x = get_frame_field (info, info->context, field, &wi->tsi); | |
883 | if (wi->val_only) | |
884 | x = init_tmp_var (info, x, &wi->tsi); | |
885 | *tp = x; | |
886 | } | |
887 | break; | |
888 | ||
889 | case ADDR_EXPR: | |
890 | { | |
891 | bool save_val_only = wi->val_only; | |
892 | tree save_sub = TREE_OPERAND (t, 0); | |
893 | ||
894 | wi->val_only = false; | |
895 | walk_tree (&TREE_OPERAND (t, 0), convert_local_reference, wi, NULL); | |
896 | wi->val_only = save_val_only; | |
897 | ||
898 | /* If we converted anything ... */ | |
899 | if (TREE_OPERAND (t, 0) != save_sub) | |
900 | { | |
901 | /* Then the frame decl is now addressable. */ | |
902 | TREE_ADDRESSABLE (info->frame_decl) = 1; | |
903 | ||
904 | /* If we are in a context where we only accept values, then | |
905 | compute the address into a temporary. */ | |
906 | if (save_val_only) | |
83e2a11b | 907 | *tp = tsi_gimplify_val (wi->info, t, &wi->tsi); |
4ee9c684 | 908 | } |
909 | } | |
910 | break; | |
911 | ||
912 | case CALL_EXPR: | |
913 | *walk_subtrees = 1; | |
914 | ||
915 | /* Ready for some fun? We need to recognize | |
916 | __builtin_stack_alloc (&x, n) | |
917 | and insert | |
918 | FRAME.x = &x | |
919 | after that. X should have use_pointer_in_frame set. We can't | |
920 | do this any earlier, since we can't meaningfully evaluate &x. */ | |
921 | ||
922 | x = get_callee_fndecl (t); | |
923 | if (!x || DECL_BUILT_IN_CLASS (x) != BUILT_IN_NORMAL) | |
924 | break; | |
925 | if (DECL_FUNCTION_CODE (x) != BUILT_IN_STACK_ALLOC) | |
926 | break; | |
927 | t = TREE_VALUE (TREE_OPERAND (t, 1)); | |
928 | if (TREE_CODE (t) != ADDR_EXPR) | |
929 | abort (); | |
930 | t = TREE_OPERAND (t, 0); | |
931 | if (TREE_CODE (t) != VAR_DECL) | |
932 | abort (); | |
933 | field = lookup_field_for_decl (info, t, NO_INSERT); | |
934 | if (!field) | |
935 | break; | |
936 | if (!use_pointer_in_frame (t)) | |
937 | abort (); | |
938 | ||
939 | x = build_addr (t); | |
940 | y = get_frame_field (info, info->context, field, &wi->tsi); | |
941 | x = build (MODIFY_EXPR, void_type_node, y, x); | |
942 | SET_EXPR_LOCUS (x, EXPR_LOCUS (tsi_stmt (wi->tsi))); | |
943 | tsi_link_after (&wi->tsi, x, TSI_SAME_STMT); | |
944 | break; | |
945 | ||
4ee9c684 | 946 | case REALPART_EXPR: |
947 | case IMAGPART_EXPR: | |
9124cf12 | 948 | case COMPONENT_REF: |
4ee9c684 | 949 | case ARRAY_REF: |
6374121b | 950 | case ARRAY_RANGE_REF: |
4ee9c684 | 951 | case BIT_FIELD_REF: |
c5bfd674 | 952 | /* Go down this entire nest and just look at the final prefix and |
953 | anything that describes the references. Otherwise, we lose track | |
954 | of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value. */ | |
4ee9c684 | 955 | wi->val_only = true; |
c5bfd674 | 956 | for (; handled_component_p (t) |
957 | || TREE_CODE (t) == REALPART_EXPR || TREE_CODE (t) == IMAGPART_EXPR; | |
958 | tp = &TREE_OPERAND (t, 0), t = *tp) | |
959 | { | |
960 | if (TREE_CODE (t) == COMPONENT_REF) | |
961 | walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi, | |
962 | NULL); | |
963 | else if (TREE_CODE (t) == ARRAY_REF | |
964 | || TREE_CODE (t) == ARRAY_RANGE_REF) | |
965 | { | |
966 | walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi, | |
967 | NULL); | |
968 | walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi, | |
969 | NULL); | |
970 | walk_tree (&TREE_OPERAND (t, 3), convert_local_reference, wi, | |
971 | NULL); | |
972 | } | |
973 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
974 | { | |
975 | walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi, | |
976 | NULL); | |
977 | walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi, | |
978 | NULL); | |
979 | } | |
980 | } | |
981 | wi->val_only = false; | |
982 | walk_tree (tp, convert_local_reference, wi, NULL); | |
4ee9c684 | 983 | break; |
984 | ||
985 | default: | |
986 | if (!DECL_P (t) && !TYPE_P (t)) | |
987 | { | |
988 | *walk_subtrees = 1; | |
989 | wi->val_only = true; | |
990 | } | |
991 | break; | |
992 | } | |
993 | ||
994 | return NULL_TREE; | |
995 | } | |
996 | ||
997 | /* Called via walk_function+walk_tree, rewrite all GOTO_EXPRs that | |
998 | reference labels from outer functions. The rewrite will be a | |
999 | call to __builtin_nonlocal_goto. */ | |
1000 | ||
1001 | static tree | |
1002 | convert_nl_goto_reference (tree *tp, int *walk_subtrees, void *data) | |
1003 | { | |
1004 | struct walk_stmt_info *wi = data; | |
1005 | struct nesting_info *info = wi->info, *i; | |
1006 | tree t = *tp, label, new_label, target_context, x, arg, field; | |
1007 | struct var_map_elt *elt; | |
1008 | void **slot; | |
1009 | ||
1010 | *walk_subtrees = 0; | |
1011 | if (TREE_CODE (t) != GOTO_EXPR) | |
1012 | return NULL_TREE; | |
1013 | label = GOTO_DESTINATION (t); | |
1014 | if (TREE_CODE (label) != LABEL_DECL) | |
1015 | return NULL_TREE; | |
1016 | target_context = decl_function_context (label); | |
1017 | if (target_context == info->context) | |
1018 | return NULL_TREE; | |
1019 | ||
1020 | for (i = info->outer; target_context != i->context; i = i->outer) | |
1021 | continue; | |
1022 | ||
1023 | /* The original user label may also be use for a normal goto, therefore | |
1024 | we must create a new label that will actually receive the abnormal | |
1025 | control transfer. This new label will be marked LABEL_NONLOCAL; this | |
365db11e | 1026 | mark will trigger proper behavior in the cfg, as well as cause the |
4ee9c684 | 1027 | (hairy target-specific) non-local goto receiver code to be generated |
1028 | when we expand rtl. */ | |
1029 | new_label = create_artificial_label (); | |
1030 | DECL_NONLOCAL (new_label) = 1; | |
1031 | ||
1032 | /* Enter this association into var_map so that we can insert the new | |
1033 | label into the IL during a second pass. */ | |
1034 | elt = xmalloc (sizeof (*elt)); | |
1035 | elt->old = label; | |
1036 | elt->new = new_label; | |
1037 | slot = htab_find_slot (i->var_map, elt, INSERT); | |
1038 | *slot = elt; | |
1039 | ||
1040 | /* Build: __builtin_nl_goto(new_label, &chain->nl_goto_field). */ | |
1041 | field = get_nl_goto_field (i); | |
1042 | x = get_frame_field (info, target_context, field, &wi->tsi); | |
1043 | x = build_addr (x); | |
83e2a11b | 1044 | x = tsi_gimplify_val (info, x, &wi->tsi); |
4ee9c684 | 1045 | arg = tree_cons (NULL, x, NULL); |
1046 | x = build_addr (new_label); | |
1047 | arg = tree_cons (NULL, x, arg); | |
1048 | x = implicit_built_in_decls[BUILT_IN_NONLOCAL_GOTO]; | |
1049 | x = build_function_call_expr (x, arg); | |
1050 | ||
1051 | SET_EXPR_LOCUS (x, EXPR_LOCUS (tsi_stmt (wi->tsi))); | |
1052 | *tsi_stmt_ptr (wi->tsi) = x; | |
1053 | ||
1054 | return NULL_TREE; | |
1055 | } | |
1056 | ||
1057 | /* Called via walk_function+walk_tree, rewrite all LABEL_EXPRs that | |
1058 | are referenced via nonlocal goto from a nested function. The rewrite | |
1059 | will involve installing a newly generated DECL_NONLOCAL label, and | |
1060 | (potentially) a branch around the rtl gunk that is assumed to be | |
1061 | attached to such a label. */ | |
1062 | ||
1063 | static tree | |
1064 | convert_nl_goto_receiver (tree *tp, int *walk_subtrees, void *data) | |
1065 | { | |
1066 | struct walk_stmt_info *wi = data; | |
1067 | struct nesting_info *info = wi->info; | |
1068 | tree t = *tp, label, new_label, x; | |
1069 | struct var_map_elt *elt, dummy; | |
1070 | tree_stmt_iterator tmp_tsi; | |
1071 | ||
1072 | *walk_subtrees = 0; | |
1073 | if (TREE_CODE (t) != LABEL_EXPR) | |
1074 | return NULL_TREE; | |
1075 | label = LABEL_EXPR_LABEL (t); | |
1076 | ||
1077 | dummy.old = label; | |
1078 | elt = htab_find (info->var_map, &dummy); | |
1079 | if (!elt) | |
1080 | return NULL_TREE; | |
1081 | new_label = elt->new; | |
1082 | ||
1083 | /* If there's any possibility that the previous statement falls through, | |
1084 | then we must branch around the new non-local label. */ | |
1085 | tmp_tsi = wi->tsi; | |
1086 | tsi_prev (&tmp_tsi); | |
1087 | if (tsi_end_p (tmp_tsi) || block_may_fallthru (tsi_stmt (tmp_tsi))) | |
1088 | { | |
1089 | x = build1 (GOTO_EXPR, void_type_node, label); | |
1090 | tsi_link_before (&wi->tsi, x, TSI_SAME_STMT); | |
1091 | } | |
1092 | x = build1 (LABEL_EXPR, void_type_node, new_label); | |
1093 | tsi_link_before (&wi->tsi, x, TSI_SAME_STMT); | |
1094 | ||
1095 | return NULL_TREE; | |
1096 | } | |
1097 | ||
1098 | /* Called via walk_function+walk_tree, rewrite all references to addresses | |
1099 | of nested functions that require the use of trampolines. The rewrite | |
1100 | will involve a reference a trampoline generated for the occasion. */ | |
1101 | ||
1102 | static tree | |
1103 | convert_tramp_reference (tree *tp, int *walk_subtrees, void *data) | |
1104 | { | |
1105 | struct walk_stmt_info *wi = data; | |
1106 | struct nesting_info *info = wi->info, *i; | |
1107 | tree t = *tp, decl, target_context, x, arg; | |
1108 | ||
1109 | *walk_subtrees = 0; | |
1110 | switch (TREE_CODE (t)) | |
1111 | { | |
1112 | case ADDR_EXPR: | |
1113 | /* Build | |
1114 | T.1 = &CHAIN->tramp; | |
1115 | T.2 = __builtin_adjust_trampoline (T.1); | |
1116 | T.3 = (func_type)T.2; | |
1117 | */ | |
1118 | ||
1119 | decl = TREE_OPERAND (t, 0); | |
1120 | if (TREE_CODE (decl) != FUNCTION_DECL) | |
1121 | break; | |
1122 | ||
1123 | /* Only need to process nested functions. */ | |
1124 | target_context = decl_function_context (decl); | |
1125 | if (!target_context) | |
1126 | break; | |
1127 | ||
1128 | /* If the nested function doesn't use a static chain, then | |
1129 | it doesn't need a trampoline. */ | |
1130 | if (DECL_NO_STATIC_CHAIN (decl)) | |
1131 | break; | |
1132 | ||
1133 | /* Lookup the immediate parent of the callee, as that's where | |
1134 | we need to insert the trampoline. */ | |
1135 | for (i = info; i->context != target_context; i = i->outer) | |
1136 | continue; | |
1137 | x = lookup_tramp_for_decl (i, decl, INSERT); | |
1138 | ||
1139 | /* Compute the address of the field holding the trampoline. */ | |
1140 | x = get_frame_field (info, target_context, x, &wi->tsi); | |
1141 | x = build_addr (x); | |
83e2a11b | 1142 | x = tsi_gimplify_val (info, x, &wi->tsi); |
4ee9c684 | 1143 | arg = tree_cons (NULL, x, NULL); |
1144 | ||
1145 | /* Do machine-specific ugliness. Normally this will involve | |
1146 | computing extra alignment, but it can really be anything. */ | |
1147 | x = implicit_built_in_decls[BUILT_IN_ADJUST_TRAMPOLINE]; | |
1148 | x = build_function_call_expr (x, arg); | |
1149 | x = init_tmp_var (info, x, &wi->tsi); | |
1150 | ||
1151 | /* Cast back to the proper function type. */ | |
1152 | x = build1 (NOP_EXPR, TREE_TYPE (t), x); | |
1153 | x = init_tmp_var (info, x, &wi->tsi); | |
1154 | ||
1155 | *tp = x; | |
1156 | break; | |
1157 | ||
1158 | case CALL_EXPR: | |
1159 | /* Only walk call arguments, lest we generate trampolines for | |
1160 | direct calls. */ | |
1161 | walk_tree (&TREE_OPERAND (t, 1), convert_tramp_reference, wi, NULL); | |
1162 | break; | |
1163 | ||
1164 | default: | |
1165 | if (!DECL_P (t) && !TYPE_P (t)) | |
1166 | *walk_subtrees = 1; | |
1167 | break; | |
1168 | } | |
1169 | ||
1170 | return NULL_TREE; | |
1171 | } | |
1172 | ||
1173 | /* Called via walk_function+walk_tree, rewrite all CALL_EXPRs that | |
1174 | reference nested functions to make sure that the static chain is | |
1175 | set up properly for the call. */ | |
1176 | ||
1177 | static tree | |
1178 | convert_call_expr (tree *tp, int *walk_subtrees, void *data) | |
1179 | { | |
1180 | struct walk_stmt_info *wi = data; | |
1181 | struct nesting_info *info = wi->info; | |
1182 | tree t = *tp, decl, target_context; | |
1183 | ||
1184 | *walk_subtrees = 0; | |
1185 | switch (TREE_CODE (t)) | |
1186 | { | |
1187 | case CALL_EXPR: | |
1188 | decl = get_callee_fndecl (t); | |
1189 | if (!decl) | |
1190 | break; | |
1191 | target_context = decl_function_context (decl); | |
1192 | if (target_context && !DECL_NO_STATIC_CHAIN (decl)) | |
1193 | TREE_OPERAND (t, 2) | |
1194 | = get_static_chain (info, target_context, &wi->tsi); | |
1195 | break; | |
1196 | ||
1197 | case RETURN_EXPR: | |
1198 | case MODIFY_EXPR: | |
80f06481 | 1199 | case WITH_SIZE_EXPR: |
1200 | /* Only return modify and with_size_expr may contain calls. */ | |
4ee9c684 | 1201 | *walk_subtrees = 1; |
1202 | break; | |
1203 | ||
1204 | default: | |
1205 | break; | |
1206 | } | |
1207 | ||
1208 | return NULL_TREE; | |
1209 | } | |
1210 | ||
1211 | /* Walk the nesting tree starting with ROOT, depth first. Convert all | |
1212 | trampolines and call expressions. On the way back up, determine if | |
1213 | a nested function actually uses its static chain; if not, remember that. */ | |
1214 | ||
1215 | static void | |
1216 | convert_all_function_calls (struct nesting_info *root) | |
1217 | { | |
1218 | do | |
1219 | { | |
1220 | if (root->inner) | |
1221 | convert_all_function_calls (root->inner); | |
1222 | ||
1223 | walk_function (convert_tramp_reference, root); | |
1224 | walk_function (convert_call_expr, root); | |
1225 | ||
1226 | /* If the function does not use a static chain, then remember that. */ | |
1227 | if (root->outer && !root->chain_decl && !root->chain_field) | |
1228 | DECL_NO_STATIC_CHAIN (root->context) = 1; | |
1229 | else | |
1230 | { | |
1231 | #ifdef ENABLE_CHECKING | |
1232 | if (DECL_NO_STATIC_CHAIN (root->context)) | |
1233 | abort (); | |
1234 | #endif | |
1235 | } | |
1236 | ||
1237 | root = root->next; | |
1238 | } | |
1239 | while (root); | |
1240 | } | |
1241 | ||
1242 | /* Do "everything else" to clean up or complete state collected by the | |
1243 | various walking passes -- lay out the types and decls, generate code | |
1244 | to initialize the frame decl, store critical expressions in the | |
1245 | struct function for rtl to find. */ | |
1246 | ||
1247 | static void | |
1248 | finalize_nesting_tree_1 (struct nesting_info *root) | |
1249 | { | |
1250 | tree stmt_list = NULL; | |
1251 | tree context = root->context; | |
1252 | struct function *sf; | |
1253 | ||
1254 | /* If we created a non-local frame type or decl, we need to lay them | |
1255 | out at this time. */ | |
1256 | if (root->frame_type) | |
1257 | { | |
1258 | layout_type (root->frame_type); | |
1259 | layout_decl (root->frame_decl, 0); | |
1260 | } | |
1261 | ||
1262 | /* If any parameters were referenced non-locally, then we need to | |
1263 | insert a copy. Likewise, if any variables were referenced by | |
1264 | pointer, we need to initialize the address. */ | |
1265 | if (root->any_parm_remapped) | |
1266 | { | |
1267 | tree p; | |
1268 | for (p = DECL_ARGUMENTS (context); p ; p = TREE_CHAIN (p)) | |
1269 | { | |
1270 | tree field, x, y; | |
1271 | ||
1272 | field = lookup_field_for_decl (root, p, NO_INSERT); | |
1273 | if (!field) | |
1274 | continue; | |
1275 | ||
1276 | if (use_pointer_in_frame (p)) | |
1277 | x = build_addr (p); | |
1278 | else | |
1279 | x = p; | |
1280 | ||
1281 | y = build (COMPONENT_REF, TREE_TYPE (field), | |
6374121b | 1282 | root->frame_decl, field, NULL_TREE); |
4ee9c684 | 1283 | x = build (MODIFY_EXPR, TREE_TYPE (field), y, x); |
1284 | append_to_statement_list (x, &stmt_list); | |
1285 | } | |
1286 | } | |
1287 | ||
1288 | /* If a chain_field was created, then it needs to be initialized | |
1289 | from chain_decl. */ | |
1290 | if (root->chain_field) | |
1291 | { | |
6374121b | 1292 | tree x = build (COMPONENT_REF, TREE_TYPE (root->chain_field), |
1293 | root->frame_decl, root->chain_field, NULL_TREE); | |
4ee9c684 | 1294 | x = build (MODIFY_EXPR, TREE_TYPE (x), x, get_chain_decl (root)); |
1295 | append_to_statement_list (x, &stmt_list); | |
1296 | } | |
1297 | ||
1298 | /* If trampolines were created, then we need to initialize them. */ | |
1299 | if (root->any_tramp_created) | |
1300 | { | |
1301 | struct nesting_info *i; | |
1302 | for (i = root->inner; i ; i = i->next) | |
1303 | { | |
1304 | tree arg, x, field; | |
1305 | ||
1306 | field = lookup_tramp_for_decl (root, i->context, NO_INSERT); | |
1307 | if (!field) | |
1308 | continue; | |
1309 | ||
1310 | if (DECL_NO_STATIC_CHAIN (i->context)) | |
1311 | x = null_pointer_node; | |
1312 | else | |
1313 | x = build_addr (root->frame_decl); | |
1314 | arg = tree_cons (NULL, x, NULL); | |
1315 | ||
1316 | x = build_addr (i->context); | |
1317 | arg = tree_cons (NULL, x, arg); | |
1318 | ||
1319 | x = build (COMPONENT_REF, TREE_TYPE (field), | |
6374121b | 1320 | root->frame_decl, field, NULL_TREE); |
4ee9c684 | 1321 | x = build_addr (x); |
1322 | arg = tree_cons (NULL, x, arg); | |
1323 | ||
1324 | x = implicit_built_in_decls[BUILT_IN_INIT_TRAMPOLINE]; | |
1325 | x = build_function_call_expr (x, arg); | |
1326 | ||
1327 | append_to_statement_list (x, &stmt_list); | |
1328 | } | |
1329 | } | |
1330 | ||
1331 | /* If we created initialization statements, insert them. */ | |
1332 | if (stmt_list) | |
1333 | { | |
1334 | annotate_all_with_locus (&stmt_list, | |
1335 | DECL_SOURCE_LOCATION (context)); | |
1336 | append_to_statement_list (BIND_EXPR_BODY (DECL_SAVED_TREE (context)), | |
1337 | &stmt_list); | |
1338 | BIND_EXPR_BODY (DECL_SAVED_TREE (context)) = stmt_list; | |
1339 | } | |
1340 | ||
1341 | /* If a chain_decl was created, then it needs to be registered with | |
1342 | struct function so that it gets initialized from the static chain | |
1343 | register at the beginning of the function. */ | |
1344 | sf = DECL_STRUCT_FUNCTION (root->context); | |
1345 | sf->static_chain_decl = root->chain_decl; | |
1346 | ||
1347 | /* Similarly for the non-local goto save area. */ | |
1348 | if (root->nl_goto_field) | |
1349 | { | |
1350 | sf->nonlocal_goto_save_area | |
1351 | = get_frame_field (root, context, root->nl_goto_field, NULL); | |
1352 | sf->has_nonlocal_label = 1; | |
1353 | } | |
1354 | ||
365db11e | 1355 | /* Make sure all new local variables get inserted into the |
4ee9c684 | 1356 | proper BIND_EXPR. */ |
1357 | if (root->new_local_var_chain) | |
1358 | declare_tmp_vars (root->new_local_var_chain, | |
1359 | DECL_SAVED_TREE (root->context)); | |
1360 | ||
1361 | /* Dump the translated tree function. */ | |
1362 | dump_function (TDI_nested, root->context); | |
1363 | } | |
1364 | ||
1365 | static void | |
1366 | finalize_nesting_tree (struct nesting_info *root) | |
1367 | { | |
1368 | do | |
1369 | { | |
1370 | if (root->inner) | |
1371 | finalize_nesting_tree (root->inner); | |
1372 | finalize_nesting_tree_1 (root); | |
1373 | root = root->next; | |
1374 | } | |
1375 | while (root); | |
1376 | } | |
1377 | ||
1378 | /* Free the data structures allocated during this pass. */ | |
1379 | ||
1380 | static void | |
1381 | free_nesting_tree (struct nesting_info *root) | |
1382 | { | |
1383 | struct nesting_info *next; | |
1384 | do | |
1385 | { | |
1386 | if (root->inner) | |
1387 | free_nesting_tree (root->inner); | |
1388 | htab_delete (root->var_map); | |
1389 | next = root->next; | |
1390 | free (root); | |
1391 | root = next; | |
1392 | } | |
1393 | while (root); | |
1394 | } | |
1395 | ||
1396 | /* Main entry point for this pass. Process FNDECL and all of its nested | |
1397 | subroutines and turn them into something less tightly bound. */ | |
1398 | ||
1399 | void | |
1400 | lower_nested_functions (tree fndecl) | |
1401 | { | |
1402 | struct nesting_info *root; | |
1403 | struct cgraph_node *cgn; | |
1404 | ||
1405 | /* If there are no nested functions, there's nothing to do. */ | |
1406 | cgn = cgraph_node (fndecl); | |
1407 | if (!cgn->nested) | |
1408 | return; | |
1409 | ||
1410 | root = create_nesting_tree (cgn); | |
1411 | walk_all_functions (convert_nonlocal_reference, root); | |
1412 | walk_all_functions (convert_local_reference, root); | |
1413 | walk_all_functions (convert_nl_goto_reference, root); | |
1414 | walk_all_functions (convert_nl_goto_receiver, root); | |
1415 | convert_all_function_calls (root); | |
1416 | finalize_nesting_tree (root); | |
1417 | free_nesting_tree (root); | |
1418 | } | |
1419 | ||
1420 | #include "gt-tree-nested.h" |