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>
5 This file is part of GCC.
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)
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.
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
19 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
24 #include "coretypes.h"
26 #include "tree-gimple.h"
27 #include "tree-iterator.h"
31 /* This is a cache of STATEMENT_LIST nodes. We create and destroy them
32 fairly often during gimplification. */
34 static GTY ((deletable (""))) tree stmt_list_cache;
37 alloc_stmt_list (void)
39 tree list = stmt_list_cache;
42 stmt_list_cache = TREE_CHAIN (list);
43 memset (list, 0, sizeof(struct tree_common));
44 TREE_SET_CODE (list, STATEMENT_LIST);
47 list = make_node (STATEMENT_LIST);
48 TREE_TYPE (list) = void_type_node;
53 free_stmt_list (tree t)
55 gcc_assert (!STATEMENT_LIST_HEAD (t));
56 gcc_assert (!STATEMENT_LIST_TAIL (t));
57 TREE_CHAIN (t) = stmt_list_cache;
61 /* Links a statement, or a chain of statements, before the current stmt. */
64 tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
66 struct tree_statement_list_node *head, *tail, *cur;
69 gcc_assert (t != i->container);
71 if (TREE_CODE (t) == STATEMENT_LIST)
73 head = STATEMENT_LIST_HEAD (t);
74 tail = STATEMENT_LIST_TAIL (t);
75 STATEMENT_LIST_HEAD (t) = NULL;
76 STATEMENT_LIST_TAIL (t) = NULL;
80 /* Empty statement lists need no work. */
83 gcc_assert (head == tail);
89 head = ggc_alloc (sizeof (*head));
96 TREE_SIDE_EFFECTS (i->container) = 1;
100 /* Link it into the list. */
103 head->prev = cur->prev;
105 head->prev->next = head;
107 STATEMENT_LIST_HEAD (i->container) = head;
113 head->prev = STATEMENT_LIST_TAIL (i->container);
115 head->prev->next = head;
117 STATEMENT_LIST_HEAD (i->container) = head;
118 STATEMENT_LIST_TAIL (i->container) = tail;
121 /* Update the iterator, if requested. */
125 case TSI_CONTINUE_LINKING:
126 case TSI_CHAIN_START:
137 /* Links a statement, or a chain of statements, after the current stmt. */
140 tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
142 struct tree_statement_list_node *head, *tail, *cur;
144 /* Die on looping. */
145 gcc_assert (t != i->container);
147 if (TREE_CODE (t) == STATEMENT_LIST)
149 head = STATEMENT_LIST_HEAD (t);
150 tail = STATEMENT_LIST_TAIL (t);
151 STATEMENT_LIST_HEAD (t) = NULL;
152 STATEMENT_LIST_TAIL (t) = NULL;
156 /* Empty statement lists need no work. */
159 gcc_assert (head == tail);
165 head = ggc_alloc (sizeof (*head));
172 TREE_SIDE_EFFECTS (i->container) = 1;
176 /* Link it into the list. */
179 tail->next = cur->next;
181 tail->next->prev = tail;
183 STATEMENT_LIST_TAIL (i->container) = tail;
189 gcc_assert (!STATEMENT_LIST_TAIL (i->container));
190 STATEMENT_LIST_HEAD (i->container) = head;
191 STATEMENT_LIST_TAIL (i->container) = tail;
194 /* Update the iterator, if requested. */
198 case TSI_CHAIN_START:
201 case TSI_CONTINUE_LINKING:
211 /* Remove a stmt from the tree list. The iterator is updated to point to
215 tsi_delink (tree_stmt_iterator *i)
217 struct tree_statement_list_node *cur, *next, *prev;
226 STATEMENT_LIST_HEAD (i->container) = next;
230 STATEMENT_LIST_TAIL (i->container) = prev;
233 TREE_SIDE_EFFECTS (i->container) = 0;
238 /* Move all statements in the statement list after I to a new
239 statement list. I itself is unchanged. */
242 tsi_split_statement_list_after (const tree_stmt_iterator *i)
244 struct tree_statement_list_node *cur, *next;
248 /* How can we possibly split after the end, or before the beginning? */
252 old_sl = i->container;
253 new_sl = alloc_stmt_list ();
254 TREE_SIDE_EFFECTS (new_sl) = 1;
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;
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. */
269 tsi_split_statement_list_before (tree_stmt_iterator *i)
271 struct tree_statement_list_node *cur, *prev;
275 /* How can we possibly split after the end, or before the beginning? */
279 old_sl = i->container;
280 new_sl = alloc_stmt_list ();
281 TREE_SIDE_EFFECTS (new_sl) = 1;
282 i->container = new_sl;
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;
293 /* Return the first expression in a sequence of COMPOUND_EXPRs,
294 or in a STATEMENT_LIST. */
297 expr_first (tree expr)
299 if (expr == NULL_TREE)
302 if (TREE_CODE (expr) == STATEMENT_LIST)
304 struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr);
305 return n ? n->stmt : NULL_TREE;
308 while (TREE_CODE (expr) == COMPOUND_EXPR)
309 expr = TREE_OPERAND (expr, 0);
313 /* Return the last expression in a sequence of COMPOUND_EXPRs,
314 or in a STATEMENT_LIST. */
317 expr_last (tree expr)
319 if (expr == NULL_TREE)
322 if (TREE_CODE (expr) == STATEMENT_LIST)
324 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
325 return n ? n->stmt : NULL_TREE;
328 while (TREE_CODE (expr) == COMPOUND_EXPR)
329 expr = TREE_OPERAND (expr, 1);
333 /* If EXPR is a single statement, naked or in a STATEMENT_LIST, then
334 return it. Otherwise return NULL. */
337 expr_only (tree expr)
339 if (expr == NULL_TREE)
342 if (TREE_CODE (expr) == STATEMENT_LIST)
344 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
345 if (n && STATEMENT_LIST_HEAD (expr) == n)
351 if (TREE_CODE (expr) == COMPOUND_EXPR)
357 #include "gt-tree-iterator.h"