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6de9cd9a DN |
1 | /* Iterator routines for manipulating GENERIC and GIMPLE tree statements. |
2 | Copyright (C) 2003, 2004 Free Software Foundation, Inc. | |
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 | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
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 | |
18 | along with GCC; see the file COPYING. If not, write to | |
366ccddb KC |
19 | the Free Software Foundation, 51 Franklin Street, Fifth Floor, |
20 | Boston, MA 02110-1301, USA. */ | |
6de9cd9a DN |
21 | |
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "tree.h" | |
eadf906f | 26 | #include "tree-gimple.h" |
6de9cd9a DN |
27 | #include "tree-iterator.h" |
28 | #include "ggc.h" | |
29 | ||
30 | ||
31 | /* This is a cache of STATEMENT_LIST nodes. We create and destroy them | |
32 | fairly often during gimplification. */ | |
33 | ||
34 | static GTY ((deletable (""))) tree stmt_list_cache; | |
35 | ||
36 | tree | |
37 | alloc_stmt_list (void) | |
38 | { | |
39 | tree list = stmt_list_cache; | |
40 | if (list) | |
41 | { | |
42 | stmt_list_cache = TREE_CHAIN (list); | |
325c3691 RH |
43 | memset (list, 0, sizeof(struct tree_common)); |
44 | TREE_SET_CODE (list, STATEMENT_LIST); | |
6de9cd9a DN |
45 | } |
46 | else | |
325c3691 RH |
47 | list = make_node (STATEMENT_LIST); |
48 | TREE_TYPE (list) = void_type_node; | |
6de9cd9a DN |
49 | return list; |
50 | } | |
51 | ||
52 | void | |
53 | free_stmt_list (tree t) | |
54 | { | |
1e128c5f GB |
55 | gcc_assert (!STATEMENT_LIST_HEAD (t)); |
56 | gcc_assert (!STATEMENT_LIST_TAIL (t)); | |
6de9cd9a DN |
57 | TREE_CHAIN (t) = stmt_list_cache; |
58 | stmt_list_cache = t; | |
59 | } | |
60 | ||
61 | /* Links a statement, or a chain of statements, before the current stmt. */ | |
62 | ||
63 | void | |
64 | tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode) | |
65 | { | |
66 | struct tree_statement_list_node *head, *tail, *cur; | |
67 | ||
68 | /* Die on looping. */ | |
1e128c5f | 69 | gcc_assert (t != i->container); |
6de9cd9a | 70 | |
6de9cd9a DN |
71 | if (TREE_CODE (t) == STATEMENT_LIST) |
72 | { | |
73 | head = STATEMENT_LIST_HEAD (t); | |
74 | tail = STATEMENT_LIST_TAIL (t); | |
75 | STATEMENT_LIST_HEAD (t) = NULL; | |
76 | STATEMENT_LIST_TAIL (t) = NULL; | |
77 | ||
78 | free_stmt_list (t); | |
79 | ||
80 | /* Empty statement lists need no work. */ | |
81 | if (!head || !tail) | |
82 | { | |
1e128c5f | 83 | gcc_assert (head == tail); |
6de9cd9a DN |
84 | return; |
85 | } | |
86 | } | |
87 | else | |
88 | { | |
89 | head = ggc_alloc (sizeof (*head)); | |
90 | head->prev = NULL; | |
91 | head->next = NULL; | |
92 | head->stmt = t; | |
93 | tail = head; | |
94 | } | |
95 | ||
325c3691 RH |
96 | TREE_SIDE_EFFECTS (i->container) = 1; |
97 | ||
6de9cd9a DN |
98 | cur = i->ptr; |
99 | ||
100 | /* Link it into the list. */ | |
101 | if (cur) | |
102 | { | |
103 | head->prev = cur->prev; | |
104 | if (head->prev) | |
105 | head->prev->next = head; | |
106 | else | |
107 | STATEMENT_LIST_HEAD (i->container) = head; | |
108 | tail->next = cur; | |
109 | cur->prev = tail; | |
110 | } | |
111 | else | |
112 | { | |
3cb005cf PB |
113 | head->prev = STATEMENT_LIST_TAIL (i->container); |
114 | if (head->prev) | |
115 | head->prev->next = head; | |
116 | else | |
117 | STATEMENT_LIST_HEAD (i->container) = head; | |
6de9cd9a DN |
118 | STATEMENT_LIST_TAIL (i->container) = tail; |
119 | } | |
120 | ||
121 | /* Update the iterator, if requested. */ | |
122 | switch (mode) | |
123 | { | |
124 | case TSI_NEW_STMT: | |
125 | case TSI_CONTINUE_LINKING: | |
126 | case TSI_CHAIN_START: | |
127 | i->ptr = head; | |
128 | break; | |
129 | case TSI_CHAIN_END: | |
130 | i->ptr = tail; | |
131 | break; | |
132 | case TSI_SAME_STMT: | |
6de9cd9a DN |
133 | break; |
134 | } | |
135 | } | |
136 | ||
137 | /* Links a statement, or a chain of statements, after the current stmt. */ | |
138 | ||
139 | void | |
140 | tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode) | |
141 | { | |
142 | struct tree_statement_list_node *head, *tail, *cur; | |
143 | ||
144 | /* Die on looping. */ | |
1e128c5f | 145 | gcc_assert (t != i->container); |
6de9cd9a | 146 | |
6de9cd9a DN |
147 | if (TREE_CODE (t) == STATEMENT_LIST) |
148 | { | |
149 | head = STATEMENT_LIST_HEAD (t); | |
150 | tail = STATEMENT_LIST_TAIL (t); | |
151 | STATEMENT_LIST_HEAD (t) = NULL; | |
152 | STATEMENT_LIST_TAIL (t) = NULL; | |
153 | ||
154 | free_stmt_list (t); | |
155 | ||
156 | /* Empty statement lists need no work. */ | |
157 | if (!head || !tail) | |
158 | { | |
1e128c5f | 159 | gcc_assert (head == tail); |
6de9cd9a DN |
160 | return; |
161 | } | |
162 | } | |
163 | else | |
164 | { | |
165 | head = ggc_alloc (sizeof (*head)); | |
166 | head->prev = NULL; | |
167 | head->next = NULL; | |
168 | head->stmt = t; | |
169 | tail = head; | |
170 | } | |
171 | ||
325c3691 RH |
172 | TREE_SIDE_EFFECTS (i->container) = 1; |
173 | ||
6de9cd9a DN |
174 | cur = i->ptr; |
175 | ||
176 | /* Link it into the list. */ | |
177 | if (cur) | |
178 | { | |
179 | tail->next = cur->next; | |
180 | if (tail->next) | |
181 | tail->next->prev = tail; | |
182 | else | |
183 | STATEMENT_LIST_TAIL (i->container) = tail; | |
184 | head->prev = cur; | |
185 | cur->next = head; | |
186 | } | |
187 | else | |
188 | { | |
1e128c5f | 189 | gcc_assert (!STATEMENT_LIST_TAIL (i->container)); |
6de9cd9a DN |
190 | STATEMENT_LIST_HEAD (i->container) = head; |
191 | STATEMENT_LIST_TAIL (i->container) = tail; | |
192 | } | |
193 | ||
194 | /* Update the iterator, if requested. */ | |
195 | switch (mode) | |
196 | { | |
197 | case TSI_NEW_STMT: | |
198 | case TSI_CHAIN_START: | |
199 | i->ptr = head; | |
200 | break; | |
201 | case TSI_CONTINUE_LINKING: | |
202 | case TSI_CHAIN_END: | |
203 | i->ptr = tail; | |
204 | break; | |
205 | case TSI_SAME_STMT: | |
1e128c5f | 206 | gcc_assert (cur); |
6de9cd9a DN |
207 | break; |
208 | } | |
209 | } | |
210 | ||
211 | /* Remove a stmt from the tree list. The iterator is updated to point to | |
212 | the next stmt. */ | |
213 | ||
214 | void | |
215 | tsi_delink (tree_stmt_iterator *i) | |
216 | { | |
217 | struct tree_statement_list_node *cur, *next, *prev; | |
218 | ||
219 | cur = i->ptr; | |
220 | next = cur->next; | |
221 | prev = cur->prev; | |
222 | ||
223 | if (prev) | |
224 | prev->next = next; | |
225 | else | |
226 | STATEMENT_LIST_HEAD (i->container) = next; | |
227 | if (next) | |
228 | next->prev = prev; | |
229 | else | |
230 | STATEMENT_LIST_TAIL (i->container) = prev; | |
231 | ||
232 | if (!next && !prev) | |
233 | TREE_SIDE_EFFECTS (i->container) = 0; | |
234 | ||
235 | i->ptr = next; | |
236 | } | |
237 | ||
238 | /* Move all statements in the statement list after I to a new | |
239 | statement list. I itself is unchanged. */ | |
240 | ||
241 | tree | |
242 | tsi_split_statement_list_after (const tree_stmt_iterator *i) | |
243 | { | |
244 | struct tree_statement_list_node *cur, *next; | |
245 | tree old_sl, new_sl; | |
246 | ||
247 | cur = i->ptr; | |
248 | /* How can we possibly split after the end, or before the beginning? */ | |
1e128c5f | 249 | gcc_assert (cur); |
6de9cd9a DN |
250 | next = cur->next; |
251 | ||
252 | old_sl = i->container; | |
253 | new_sl = alloc_stmt_list (); | |
254 | TREE_SIDE_EFFECTS (new_sl) = 1; | |
255 | ||
256 | STATEMENT_LIST_HEAD (new_sl) = next; | |
257 | STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl); | |
258 | STATEMENT_LIST_TAIL (old_sl) = cur; | |
259 | cur->next = NULL; | |
260 | next->prev = NULL; | |
261 | ||
262 | return new_sl; | |
263 | } | |
264 | ||
265 | /* Move all statements in the statement list before I to a new | |
266 | statement list. I is set to the head of the new list. */ | |
267 | ||
268 | tree | |
269 | tsi_split_statement_list_before (tree_stmt_iterator *i) | |
270 | { | |
271 | struct tree_statement_list_node *cur, *prev; | |
272 | tree old_sl, new_sl; | |
273 | ||
274 | cur = i->ptr; | |
275 | /* How can we possibly split after the end, or before the beginning? */ | |
1e128c5f | 276 | gcc_assert (cur); |
6de9cd9a DN |
277 | prev = cur->prev; |
278 | ||
279 | old_sl = i->container; | |
280 | new_sl = alloc_stmt_list (); | |
281 | TREE_SIDE_EFFECTS (new_sl) = 1; | |
282 | i->container = new_sl; | |
283 | ||
284 | STATEMENT_LIST_HEAD (new_sl) = cur; | |
285 | STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl); | |
286 | STATEMENT_LIST_TAIL (old_sl) = prev; | |
287 | cur->prev = NULL; | |
288 | prev->next = NULL; | |
289 | ||
290 | return new_sl; | |
291 | } | |
292 | ||
293 | /* Return the first expression in a sequence of COMPOUND_EXPRs, | |
294 | or in a STATEMENT_LIST. */ | |
295 | ||
296 | tree | |
297 | expr_first (tree expr) | |
298 | { | |
299 | if (expr == NULL_TREE) | |
300 | return expr; | |
301 | ||
302 | if (TREE_CODE (expr) == STATEMENT_LIST) | |
303 | { | |
304 | struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr); | |
305 | return n ? n->stmt : NULL_TREE; | |
306 | } | |
307 | ||
308 | while (TREE_CODE (expr) == COMPOUND_EXPR) | |
309 | expr = TREE_OPERAND (expr, 0); | |
310 | return expr; | |
311 | } | |
312 | ||
313 | /* Return the last expression in a sequence of COMPOUND_EXPRs, | |
314 | or in a STATEMENT_LIST. */ | |
315 | ||
316 | tree | |
317 | expr_last (tree expr) | |
318 | { | |
319 | if (expr == NULL_TREE) | |
320 | return expr; | |
321 | ||
322 | if (TREE_CODE (expr) == STATEMENT_LIST) | |
323 | { | |
324 | struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr); | |
325 | return n ? n->stmt : NULL_TREE; | |
326 | } | |
327 | ||
328 | while (TREE_CODE (expr) == COMPOUND_EXPR) | |
329 | expr = TREE_OPERAND (expr, 1); | |
330 | return expr; | |
331 | } | |
332 | ||
333 | /* If EXPR is a single statement, naked or in a STATEMENT_LIST, then | |
334 | return it. Otherwise return NULL. */ | |
335 | ||
336 | tree | |
337 | expr_only (tree expr) | |
338 | { | |
339 | if (expr == NULL_TREE) | |
340 | return NULL_TREE; | |
341 | ||
342 | if (TREE_CODE (expr) == STATEMENT_LIST) | |
343 | { | |
344 | struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr); | |
345 | if (n && STATEMENT_LIST_HEAD (expr) == n) | |
346 | return n->stmt; | |
347 | else | |
348 | return NULL_TREE; | |
349 | } | |
350 | ||
351 | if (TREE_CODE (expr) == COMPOUND_EXPR) | |
352 | return NULL_TREE; | |
353 | ||
354 | return expr; | |
355 | } | |
356 | ||
357 | #include "gt-tree-iterator.h" |