1 /* Iterator routines for manipulating GENERIC and GIMPLE tree statements.
2 Copyright (C) 2003, 2004, 2007, 2008 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 3, 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 COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
26 #include "tree-iterator.h"
30 /* This is a cache of STATEMENT_LIST nodes. We create and destroy them
31 fairly often during gimplification. */
33 static GTY ((deletable (""))) tree stmt_list_cache;
36 alloc_stmt_list (void)
38 tree list = stmt_list_cache;
41 stmt_list_cache = TREE_CHAIN (list);
42 gcc_assert (stmt_list_cache != 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 /* If this triggers, it's a sign that the same list is being freed
59 gcc_assert (t != stmt_list_cache || stmt_list_cache == NULL);
60 TREE_CHAIN (t) = stmt_list_cache;
64 /* A subroutine of append_to_statement_list{,_force}. T is not NULL. */
67 append_to_statement_list_1 (tree t, tree *list_p)
74 if (t && TREE_CODE (t) == STATEMENT_LIST)
79 *list_p = list = alloc_stmt_list ();
83 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
86 /* Add T to the end of the list container pointed to by LIST_P.
87 If T is an expression with no effects, it is ignored. */
90 append_to_statement_list (tree t, tree *list_p)
92 if (t && TREE_SIDE_EFFECTS (t))
93 append_to_statement_list_1 (t, list_p);
96 /* Similar, but the statement is always added, regardless of side effects. */
99 append_to_statement_list_force (tree t, tree *list_p)
102 append_to_statement_list_1 (t, list_p);
105 /* Links a statement, or a chain of statements, before the current stmt. */
108 tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
110 struct tree_statement_list_node *head, *tail, *cur;
112 /* Die on looping. */
113 gcc_assert (t != i->container);
115 if (TREE_CODE (t) == STATEMENT_LIST)
117 head = STATEMENT_LIST_HEAD (t);
118 tail = STATEMENT_LIST_TAIL (t);
119 STATEMENT_LIST_HEAD (t) = NULL;
120 STATEMENT_LIST_TAIL (t) = NULL;
124 /* Empty statement lists need no work. */
127 gcc_assert (head == tail);
133 head = GGC_NEW (struct tree_statement_list_node);
140 TREE_SIDE_EFFECTS (i->container) = 1;
144 /* Link it into the list. */
147 head->prev = cur->prev;
149 head->prev->next = head;
151 STATEMENT_LIST_HEAD (i->container) = head;
157 head->prev = STATEMENT_LIST_TAIL (i->container);
159 head->prev->next = head;
161 STATEMENT_LIST_HEAD (i->container) = head;
162 STATEMENT_LIST_TAIL (i->container) = tail;
165 /* Update the iterator, if requested. */
169 case TSI_CONTINUE_LINKING:
170 case TSI_CHAIN_START:
181 /* Links a statement, or a chain of statements, after the current stmt. */
184 tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
186 struct tree_statement_list_node *head, *tail, *cur;
188 /* Die on looping. */
189 gcc_assert (t != i->container);
191 if (TREE_CODE (t) == STATEMENT_LIST)
193 head = STATEMENT_LIST_HEAD (t);
194 tail = STATEMENT_LIST_TAIL (t);
195 STATEMENT_LIST_HEAD (t) = NULL;
196 STATEMENT_LIST_TAIL (t) = NULL;
200 /* Empty statement lists need no work. */
203 gcc_assert (head == tail);
209 head = GGC_NEW (struct tree_statement_list_node);
216 TREE_SIDE_EFFECTS (i->container) = 1;
220 /* Link it into the list. */
223 tail->next = cur->next;
225 tail->next->prev = tail;
227 STATEMENT_LIST_TAIL (i->container) = tail;
233 gcc_assert (!STATEMENT_LIST_TAIL (i->container));
234 STATEMENT_LIST_HEAD (i->container) = head;
235 STATEMENT_LIST_TAIL (i->container) = tail;
238 /* Update the iterator, if requested. */
242 case TSI_CHAIN_START:
245 case TSI_CONTINUE_LINKING:
255 /* Remove a stmt from the tree list. The iterator is updated to point to
259 tsi_delink (tree_stmt_iterator *i)
261 struct tree_statement_list_node *cur, *next, *prev;
270 STATEMENT_LIST_HEAD (i->container) = next;
274 STATEMENT_LIST_TAIL (i->container) = prev;
277 TREE_SIDE_EFFECTS (i->container) = 0;
282 /* Return the first expression in a sequence of COMPOUND_EXPRs,
283 or in a STATEMENT_LIST. */
286 expr_first (tree expr)
288 if (expr == NULL_TREE)
291 if (TREE_CODE (expr) == STATEMENT_LIST)
293 struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr);
294 return n ? n->stmt : NULL_TREE;
297 while (TREE_CODE (expr) == COMPOUND_EXPR)
298 expr = TREE_OPERAND (expr, 0);
303 /* Return the last expression in a sequence of COMPOUND_EXPRs,
304 or in a STATEMENT_LIST. */
307 expr_last (tree expr)
309 if (expr == NULL_TREE)
312 if (TREE_CODE (expr) == STATEMENT_LIST)
314 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
315 return n ? n->stmt : NULL_TREE;
318 while (TREE_CODE (expr) == COMPOUND_EXPR)
319 expr = TREE_OPERAND (expr, 1);
324 #include "gt-tree-iterator.h"