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 gcc_assert (stmt_list_cache != list);
44 memset (list, 0, sizeof(struct tree_common));
45 TREE_SET_CODE (list, STATEMENT_LIST);
48 list = make_node (STATEMENT_LIST);
49 TREE_TYPE (list) = void_type_node;
54 free_stmt_list (tree t)
56 gcc_assert (!STATEMENT_LIST_HEAD (t));
57 gcc_assert (!STATEMENT_LIST_TAIL (t));
58 /* If this triggers, it's a sign that the same list is being freed
60 gcc_assert (t != stmt_list_cache || stmt_list_cache == NULL);
61 TREE_CHAIN (t) = stmt_list_cache;
65 /* Links a statement, or a chain of statements, before the current stmt. */
68 tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
70 struct tree_statement_list_node *head, *tail, *cur;
73 gcc_assert (t != i->container);
75 if (TREE_CODE (t) == STATEMENT_LIST)
77 head = STATEMENT_LIST_HEAD (t);
78 tail = STATEMENT_LIST_TAIL (t);
79 STATEMENT_LIST_HEAD (t) = NULL;
80 STATEMENT_LIST_TAIL (t) = NULL;
84 /* Empty statement lists need no work. */
87 gcc_assert (head == tail);
93 head = ggc_alloc (sizeof (*head));
100 TREE_SIDE_EFFECTS (i->container) = 1;
104 /* Link it into the list. */
107 head->prev = cur->prev;
109 head->prev->next = head;
111 STATEMENT_LIST_HEAD (i->container) = head;
117 head->prev = STATEMENT_LIST_TAIL (i->container);
119 head->prev->next = head;
121 STATEMENT_LIST_HEAD (i->container) = head;
122 STATEMENT_LIST_TAIL (i->container) = tail;
125 /* Update the iterator, if requested. */
129 case TSI_CONTINUE_LINKING:
130 case TSI_CHAIN_START:
141 /* Links a statement, or a chain of statements, after the current stmt. */
144 tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
146 struct tree_statement_list_node *head, *tail, *cur;
148 /* Die on looping. */
149 gcc_assert (t != i->container);
151 if (TREE_CODE (t) == STATEMENT_LIST)
153 head = STATEMENT_LIST_HEAD (t);
154 tail = STATEMENT_LIST_TAIL (t);
155 STATEMENT_LIST_HEAD (t) = NULL;
156 STATEMENT_LIST_TAIL (t) = NULL;
160 /* Empty statement lists need no work. */
163 gcc_assert (head == tail);
169 head = ggc_alloc (sizeof (*head));
176 TREE_SIDE_EFFECTS (i->container) = 1;
180 /* Link it into the list. */
183 tail->next = cur->next;
185 tail->next->prev = tail;
187 STATEMENT_LIST_TAIL (i->container) = tail;
193 gcc_assert (!STATEMENT_LIST_TAIL (i->container));
194 STATEMENT_LIST_HEAD (i->container) = head;
195 STATEMENT_LIST_TAIL (i->container) = tail;
198 /* Update the iterator, if requested. */
202 case TSI_CHAIN_START:
205 case TSI_CONTINUE_LINKING:
215 /* Remove a stmt from the tree list. The iterator is updated to point to
219 tsi_delink (tree_stmt_iterator *i)
221 struct tree_statement_list_node *cur, *next, *prev;
230 STATEMENT_LIST_HEAD (i->container) = next;
234 STATEMENT_LIST_TAIL (i->container) = prev;
237 TREE_SIDE_EFFECTS (i->container) = 0;
242 /* Move all statements in the statement list after I to a new
243 statement list. I itself is unchanged. */
246 tsi_split_statement_list_after (const tree_stmt_iterator *i)
248 struct tree_statement_list_node *cur, *next;
252 /* How can we possibly split after the end, or before the beginning? */
256 old_sl = i->container;
257 new_sl = alloc_stmt_list ();
258 TREE_SIDE_EFFECTS (new_sl) = 1;
260 STATEMENT_LIST_HEAD (new_sl) = next;
261 STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl);
262 STATEMENT_LIST_TAIL (old_sl) = cur;
269 /* Move all statements in the statement list before I to a new
270 statement list. I is set to the head of the new list. */
273 tsi_split_statement_list_before (tree_stmt_iterator *i)
275 struct tree_statement_list_node *cur, *prev;
279 /* How can we possibly split after the end, or before the beginning? */
283 old_sl = i->container;
284 new_sl = alloc_stmt_list ();
285 TREE_SIDE_EFFECTS (new_sl) = 1;
286 i->container = new_sl;
288 STATEMENT_LIST_HEAD (new_sl) = cur;
289 STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl);
290 STATEMENT_LIST_TAIL (old_sl) = prev;
298 /* Return the first expression in a sequence of COMPOUND_EXPRs,
299 or in a STATEMENT_LIST. */
302 expr_first (tree expr)
304 if (expr == NULL_TREE)
307 if (TREE_CODE (expr) == STATEMENT_LIST)
309 struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr);
310 return n ? n->stmt : NULL_TREE;
313 while (TREE_CODE (expr) == COMPOUND_EXPR)
314 expr = TREE_OPERAND (expr, 0);
318 /* Return the last expression in a sequence of COMPOUND_EXPRs,
319 or in a STATEMENT_LIST. */
322 expr_last (tree expr)
324 if (expr == NULL_TREE)
327 if (TREE_CODE (expr) == STATEMENT_LIST)
329 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
330 return n ? n->stmt : NULL_TREE;
333 while (TREE_CODE (expr) == COMPOUND_EXPR)
334 expr = TREE_OPERAND (expr, 1);
338 /* If EXPR is a single statement return it. If EXPR is a
339 STATEMENT_LIST containing exactly one statement S, return S.
340 Otherwise, return NULL. */
343 expr_only (tree expr)
345 if (expr == NULL_TREE)
348 if (TREE_CODE (expr) == STATEMENT_LIST)
350 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
351 if (n && STATEMENT_LIST_HEAD (expr) == n)
357 if (TREE_CODE (expr) == COMPOUND_EXPR)
363 #include "gt-tree-iterator.h"