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, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, 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 TREE_CHAIN (list) = NULL;
44 TREE_SIDE_EFFECTS (list) = 0;
48 list = make_node (STATEMENT_LIST);
49 TREE_TYPE (list) = void_type_node;
55 free_stmt_list (tree t)
57 #ifdef ENABLE_CHECKING
58 if (STATEMENT_LIST_HEAD (t) || STATEMENT_LIST_TAIL (t))
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 if (t == i->container)
76 TREE_SIDE_EFFECTS (i->container) = 1;
78 if (TREE_CODE (t) == STATEMENT_LIST)
80 head = STATEMENT_LIST_HEAD (t);
81 tail = STATEMENT_LIST_TAIL (t);
82 STATEMENT_LIST_HEAD (t) = NULL;
83 STATEMENT_LIST_TAIL (t) = NULL;
87 /* Empty statement lists need no work. */
97 head = ggc_alloc (sizeof (*head));
106 /* Link it into the list. */
109 head->prev = cur->prev;
111 head->prev->next = head;
113 STATEMENT_LIST_HEAD (i->container) = head;
119 if (STATEMENT_LIST_TAIL (i->container))
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:
143 /* Links a statement, or a chain of statements, after the current stmt. */
146 tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
148 struct tree_statement_list_node *head, *tail, *cur;
150 /* Die on looping. */
151 if (t == i->container)
154 TREE_SIDE_EFFECTS (i->container) = 1;
156 if (TREE_CODE (t) == STATEMENT_LIST)
158 head = STATEMENT_LIST_HEAD (t);
159 tail = STATEMENT_LIST_TAIL (t);
160 STATEMENT_LIST_HEAD (t) = NULL;
161 STATEMENT_LIST_TAIL (t) = NULL;
165 /* Empty statement lists need no work. */
175 head = ggc_alloc (sizeof (*head));
184 /* Link it into the list. */
187 tail->next = cur->next;
189 tail->next->prev = tail;
191 STATEMENT_LIST_TAIL (i->container) = tail;
197 if (STATEMENT_LIST_TAIL (i->container))
199 STATEMENT_LIST_HEAD (i->container) = head;
200 STATEMENT_LIST_TAIL (i->container) = tail;
203 /* Update the iterator, if requested. */
207 case TSI_CHAIN_START:
210 case TSI_CONTINUE_LINKING:
221 /* Remove a stmt from the tree list. The iterator is updated to point to
225 tsi_delink (tree_stmt_iterator *i)
227 struct tree_statement_list_node *cur, *next, *prev;
236 STATEMENT_LIST_HEAD (i->container) = next;
240 STATEMENT_LIST_TAIL (i->container) = prev;
243 TREE_SIDE_EFFECTS (i->container) = 0;
248 /* Move all statements in the statement list after I to a new
249 statement list. I itself is unchanged. */
252 tsi_split_statement_list_after (const tree_stmt_iterator *i)
254 struct tree_statement_list_node *cur, *next;
258 /* How can we possibly split after the end, or before the beginning? */
263 old_sl = i->container;
264 new_sl = alloc_stmt_list ();
265 TREE_SIDE_EFFECTS (new_sl) = 1;
267 STATEMENT_LIST_HEAD (new_sl) = next;
268 STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl);
269 STATEMENT_LIST_TAIL (old_sl) = cur;
276 /* Move all statements in the statement list before I to a new
277 statement list. I is set to the head of the new list. */
280 tsi_split_statement_list_before (tree_stmt_iterator *i)
282 struct tree_statement_list_node *cur, *prev;
286 /* How can we possibly split after the end, or before the beginning? */
291 old_sl = i->container;
292 new_sl = alloc_stmt_list ();
293 TREE_SIDE_EFFECTS (new_sl) = 1;
294 i->container = new_sl;
296 STATEMENT_LIST_HEAD (new_sl) = cur;
297 STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl);
298 STATEMENT_LIST_TAIL (old_sl) = prev;
305 /* Return the first expression in a sequence of COMPOUND_EXPRs,
306 or in a STATEMENT_LIST. */
309 expr_first (tree expr)
311 if (expr == NULL_TREE)
314 if (TREE_CODE (expr) == STATEMENT_LIST)
316 struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr);
317 return n ? n->stmt : NULL_TREE;
320 while (TREE_CODE (expr) == COMPOUND_EXPR)
321 expr = TREE_OPERAND (expr, 0);
325 /* Return the last expression in a sequence of COMPOUND_EXPRs,
326 or in a STATEMENT_LIST. */
329 expr_last (tree expr)
331 if (expr == NULL_TREE)
334 if (TREE_CODE (expr) == STATEMENT_LIST)
336 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
337 return n ? n->stmt : NULL_TREE;
340 while (TREE_CODE (expr) == COMPOUND_EXPR)
341 expr = TREE_OPERAND (expr, 1);
345 /* If EXPR is a single statement, naked or in a STATEMENT_LIST, then
346 return it. Otherwise return NULL. */
349 expr_only (tree expr)
351 if (expr == NULL_TREE)
354 if (TREE_CODE (expr) == STATEMENT_LIST)
356 struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr);
357 if (n && STATEMENT_LIST_HEAD (expr) == n)
363 if (TREE_CODE (expr) == COMPOUND_EXPR)
369 #include "gt-tree-iterator.h"