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4ee9c684 | 1 | /* Iterator routines for manipulating GENERIC and GIMPLE tree statements. |
fbd26352 | 2 | Copyright (C) 2003-2019 Free Software Foundation, Inc. |
4ee9c684 | 3 | Contributed by Andrew MacLeod <amacleod@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
8c4c00c1 | 9 | the Free Software Foundation; either version 3, or (at your option) |
4ee9c684 | 10 | any later version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
4ee9c684 | 20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
7c29e30e | 24 | #include "tree.h" |
4ee9c684 | 25 | #include "tree-iterator.h" |
4ee9c684 | 26 | |
27 | ||
28 | /* This is a cache of STATEMENT_LIST nodes. We create and destroy them | |
29 | fairly often during gimplification. */ | |
30 | ||
f1f41a6c | 31 | static GTY ((deletable (""))) vec<tree, va_gc> *stmt_list_cache; |
4ee9c684 | 32 | |
33 | tree | |
34 | alloc_stmt_list (void) | |
35 | { | |
cacfdc02 | 36 | tree list; |
f1f41a6c | 37 | if (!vec_safe_is_empty (stmt_list_cache)) |
4ee9c684 | 38 | { |
f1f41a6c | 39 | list = stmt_list_cache->pop (); |
9af5ce0c | 40 | memset (list, 0, sizeof (struct tree_base)); |
2363ef00 | 41 | TREE_SET_CODE (list, STATEMENT_LIST); |
4ee9c684 | 42 | } |
43 | else | |
2ea33951 | 44 | { |
45 | list = make_node (STATEMENT_LIST); | |
46 | TREE_SIDE_EFFECTS (list) = 0; | |
47 | } | |
2363ef00 | 48 | TREE_TYPE (list) = void_type_node; |
4ee9c684 | 49 | return list; |
50 | } | |
51 | ||
52 | void | |
53 | free_stmt_list (tree t) | |
54 | { | |
8c0963c4 | 55 | gcc_assert (!STATEMENT_LIST_HEAD (t)); |
56 | gcc_assert (!STATEMENT_LIST_TAIL (t)); | |
f1f41a6c | 57 | vec_safe_push (stmt_list_cache, t); |
4ee9c684 | 58 | } |
59 | ||
115133dd | 60 | /* A subroutine of append_to_statement_list{,_force}. T is not NULL. */ |
61 | ||
62 | static void | |
63 | append_to_statement_list_1 (tree t, tree *list_p) | |
64 | { | |
65 | tree list = *list_p; | |
66 | tree_stmt_iterator i; | |
67 | ||
68 | if (!list) | |
69 | { | |
70 | if (t && TREE_CODE (t) == STATEMENT_LIST) | |
71 | { | |
72 | *list_p = t; | |
73 | return; | |
74 | } | |
75 | *list_p = list = alloc_stmt_list (); | |
76 | } | |
85d618f3 | 77 | else if (TREE_CODE (list) != STATEMENT_LIST) |
78 | { | |
79 | tree first = list; | |
80 | *list_p = list = alloc_stmt_list (); | |
81 | i = tsi_last (list); | |
82 | tsi_link_after (&i, first, TSI_CONTINUE_LINKING); | |
83 | } | |
115133dd | 84 | |
85 | i = tsi_last (list); | |
86 | tsi_link_after (&i, t, TSI_CONTINUE_LINKING); | |
87 | } | |
88 | ||
89 | /* Add T to the end of the list container pointed to by LIST_P. | |
90 | If T is an expression with no effects, it is ignored. */ | |
91 | ||
92 | void | |
93 | append_to_statement_list (tree t, tree *list_p) | |
94 | { | |
90567983 | 95 | if (t && (TREE_SIDE_EFFECTS (t) || TREE_CODE (t) == DEBUG_BEGIN_STMT)) |
115133dd | 96 | append_to_statement_list_1 (t, list_p); |
97 | } | |
98 | ||
99 | /* Similar, but the statement is always added, regardless of side effects. */ | |
100 | ||
101 | void | |
102 | append_to_statement_list_force (tree t, tree *list_p) | |
103 | { | |
104 | if (t != NULL_TREE) | |
105 | append_to_statement_list_1 (t, list_p); | |
106 | } | |
107 | ||
4ee9c684 | 108 | /* Links a statement, or a chain of statements, before the current stmt. */ |
109 | ||
110 | void | |
111 | tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode) | |
112 | { | |
113 | struct tree_statement_list_node *head, *tail, *cur; | |
114 | ||
115 | /* Die on looping. */ | |
8c0963c4 | 116 | gcc_assert (t != i->container); |
4ee9c684 | 117 | |
4ee9c684 | 118 | if (TREE_CODE (t) == STATEMENT_LIST) |
119 | { | |
120 | head = STATEMENT_LIST_HEAD (t); | |
121 | tail = STATEMENT_LIST_TAIL (t); | |
122 | STATEMENT_LIST_HEAD (t) = NULL; | |
123 | STATEMENT_LIST_TAIL (t) = NULL; | |
124 | ||
125 | free_stmt_list (t); | |
126 | ||
127 | /* Empty statement lists need no work. */ | |
128 | if (!head || !tail) | |
129 | { | |
8c0963c4 | 130 | gcc_assert (head == tail); |
4ee9c684 | 131 | return; |
132 | } | |
133 | } | |
134 | else | |
135 | { | |
25a27413 | 136 | head = ggc_alloc<tree_statement_list_node> (); |
4ee9c684 | 137 | head->prev = NULL; |
138 | head->next = NULL; | |
139 | head->stmt = t; | |
140 | tail = head; | |
141 | } | |
142 | ||
90567983 | 143 | if (TREE_CODE (t) != DEBUG_BEGIN_STMT) |
144 | TREE_SIDE_EFFECTS (i->container) = 1; | |
2363ef00 | 145 | |
4ee9c684 | 146 | cur = i->ptr; |
147 | ||
148 | /* Link it into the list. */ | |
149 | if (cur) | |
150 | { | |
151 | head->prev = cur->prev; | |
152 | if (head->prev) | |
153 | head->prev->next = head; | |
154 | else | |
155 | STATEMENT_LIST_HEAD (i->container) = head; | |
156 | tail->next = cur; | |
157 | cur->prev = tail; | |
158 | } | |
159 | else | |
160 | { | |
96d249d8 | 161 | head->prev = STATEMENT_LIST_TAIL (i->container); |
162 | if (head->prev) | |
163 | head->prev->next = head; | |
164 | else | |
165 | STATEMENT_LIST_HEAD (i->container) = head; | |
4ee9c684 | 166 | STATEMENT_LIST_TAIL (i->container) = tail; |
167 | } | |
168 | ||
169 | /* Update the iterator, if requested. */ | |
170 | switch (mode) | |
171 | { | |
172 | case TSI_NEW_STMT: | |
173 | case TSI_CONTINUE_LINKING: | |
174 | case TSI_CHAIN_START: | |
175 | i->ptr = head; | |
176 | break; | |
177 | case TSI_CHAIN_END: | |
178 | i->ptr = tail; | |
179 | break; | |
180 | case TSI_SAME_STMT: | |
4ee9c684 | 181 | break; |
182 | } | |
183 | } | |
184 | ||
185 | /* Links a statement, or a chain of statements, after the current stmt. */ | |
186 | ||
187 | void | |
188 | tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode) | |
189 | { | |
190 | struct tree_statement_list_node *head, *tail, *cur; | |
191 | ||
192 | /* Die on looping. */ | |
8c0963c4 | 193 | gcc_assert (t != i->container); |
4ee9c684 | 194 | |
4ee9c684 | 195 | if (TREE_CODE (t) == STATEMENT_LIST) |
196 | { | |
197 | head = STATEMENT_LIST_HEAD (t); | |
198 | tail = STATEMENT_LIST_TAIL (t); | |
199 | STATEMENT_LIST_HEAD (t) = NULL; | |
200 | STATEMENT_LIST_TAIL (t) = NULL; | |
201 | ||
202 | free_stmt_list (t); | |
203 | ||
204 | /* Empty statement lists need no work. */ | |
205 | if (!head || !tail) | |
206 | { | |
8c0963c4 | 207 | gcc_assert (head == tail); |
4ee9c684 | 208 | return; |
209 | } | |
210 | } | |
211 | else | |
212 | { | |
25a27413 | 213 | head = ggc_alloc<tree_statement_list_node> (); |
4ee9c684 | 214 | head->prev = NULL; |
215 | head->next = NULL; | |
216 | head->stmt = t; | |
217 | tail = head; | |
218 | } | |
219 | ||
90567983 | 220 | if (TREE_CODE (t) != DEBUG_BEGIN_STMT) |
221 | TREE_SIDE_EFFECTS (i->container) = 1; | |
2363ef00 | 222 | |
4ee9c684 | 223 | cur = i->ptr; |
224 | ||
225 | /* Link it into the list. */ | |
226 | if (cur) | |
227 | { | |
228 | tail->next = cur->next; | |
229 | if (tail->next) | |
230 | tail->next->prev = tail; | |
231 | else | |
232 | STATEMENT_LIST_TAIL (i->container) = tail; | |
233 | head->prev = cur; | |
234 | cur->next = head; | |
235 | } | |
236 | else | |
237 | { | |
8c0963c4 | 238 | gcc_assert (!STATEMENT_LIST_TAIL (i->container)); |
4ee9c684 | 239 | STATEMENT_LIST_HEAD (i->container) = head; |
240 | STATEMENT_LIST_TAIL (i->container) = tail; | |
241 | } | |
242 | ||
243 | /* Update the iterator, if requested. */ | |
244 | switch (mode) | |
245 | { | |
246 | case TSI_NEW_STMT: | |
247 | case TSI_CHAIN_START: | |
248 | i->ptr = head; | |
249 | break; | |
250 | case TSI_CONTINUE_LINKING: | |
251 | case TSI_CHAIN_END: | |
252 | i->ptr = tail; | |
253 | break; | |
254 | case TSI_SAME_STMT: | |
8c0963c4 | 255 | gcc_assert (cur); |
4ee9c684 | 256 | break; |
257 | } | |
258 | } | |
259 | ||
260 | /* Remove a stmt from the tree list. The iterator is updated to point to | |
261 | the next stmt. */ | |
262 | ||
263 | void | |
264 | tsi_delink (tree_stmt_iterator *i) | |
265 | { | |
266 | struct tree_statement_list_node *cur, *next, *prev; | |
267 | ||
268 | cur = i->ptr; | |
269 | next = cur->next; | |
270 | prev = cur->prev; | |
271 | ||
272 | if (prev) | |
273 | prev->next = next; | |
274 | else | |
275 | STATEMENT_LIST_HEAD (i->container) = next; | |
276 | if (next) | |
277 | next->prev = prev; | |
278 | else | |
279 | STATEMENT_LIST_TAIL (i->container) = prev; | |
280 | ||
281 | if (!next && !prev) | |
282 | TREE_SIDE_EFFECTS (i->container) = 0; | |
283 | ||
284 | i->ptr = next; | |
285 | } | |
286 | ||
90567983 | 287 | /* Return the first expression in a sequence of COMPOUND_EXPRs, or in |
288 | a STATEMENT_LIST, disregarding DEBUG_BEGIN_STMTs, recursing into a | |
289 | STATEMENT_LIST if that's the first non-DEBUG_BEGIN_STMT. */ | |
4ee9c684 | 290 | |
291 | tree | |
292 | expr_first (tree expr) | |
293 | { | |
ce4469fa | 294 | if (expr == NULL_TREE) |
295 | return expr; | |
4ee9c684 | 296 | |
ce4469fa | 297 | if (TREE_CODE (expr) == STATEMENT_LIST) |
298 | { | |
299 | struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr); | |
90567983 | 300 | if (!n) |
301 | return NULL_TREE; | |
302 | while (TREE_CODE (n->stmt) == DEBUG_BEGIN_STMT) | |
303 | { | |
304 | n = n->next; | |
305 | if (!n) | |
306 | return NULL_TREE; | |
307 | } | |
308 | /* If the first non-debug stmt is not a statement list, we | |
309 | already know it's what we're looking for. */ | |
310 | if (TREE_CODE (n->stmt) != STATEMENT_LIST) | |
311 | return n->stmt; | |
312 | ||
313 | return expr_first (n->stmt); | |
ce4469fa | 314 | } |
315 | ||
316 | while (TREE_CODE (expr) == COMPOUND_EXPR) | |
317 | expr = TREE_OPERAND (expr, 0); | |
318 | ||
319 | return expr; | |
4ee9c684 | 320 | } |
321 | ||
90567983 | 322 | /* Return the last expression in a sequence of COMPOUND_EXPRs, or in a |
323 | STATEMENT_LIST, disregarding DEBUG_BEGIN_STMTs, recursing into a | |
324 | STATEMENT_LIST if that's the last non-DEBUG_BEGIN_STMT. */ | |
4ee9c684 | 325 | |
326 | tree | |
327 | expr_last (tree expr) | |
328 | { | |
ce4469fa | 329 | if (expr == NULL_TREE) |
330 | return expr; | |
4ee9c684 | 331 | |
ce4469fa | 332 | if (TREE_CODE (expr) == STATEMENT_LIST) |
333 | { | |
334 | struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr); | |
90567983 | 335 | if (!n) |
336 | return NULL_TREE; | |
337 | while (TREE_CODE (n->stmt) == DEBUG_BEGIN_STMT) | |
338 | { | |
339 | n = n->prev; | |
340 | if (!n) | |
341 | return NULL_TREE; | |
342 | } | |
343 | /* If the last non-debug stmt is not a statement list, we | |
344 | already know it's what we're looking for. */ | |
345 | if (TREE_CODE (n->stmt) != STATEMENT_LIST) | |
346 | return n->stmt; | |
347 | ||
348 | return expr_last (n->stmt); | |
ce4469fa | 349 | } |
350 | ||
351 | while (TREE_CODE (expr) == COMPOUND_EXPR) | |
352 | expr = TREE_OPERAND (expr, 1); | |
353 | ||
354 | return expr; | |
4ee9c684 | 355 | } |
356 | ||
4ee9c684 | 357 | #include "gt-tree-iterator.h" |