diff options
Diffstat (limited to 'gcc/tree-iterator.c')
| -rw-r--r-- | gcc/tree-iterator.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/gcc/tree-iterator.c b/gcc/tree-iterator.c new file mode 100644 index 000000000..05764daa1 --- /dev/null +++ b/gcc/tree-iterator.c @@ -0,0 +1,325 @@ +/* Iterator routines for manipulating GENERIC and GIMPLE tree statements. + Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010 + Free Software Foundation, Inc. + Contributed by Andrew MacLeod <amacleod@redhat.com> + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "gimple.h" +#include "tree-iterator.h" +#include "ggc.h" + + +/* This is a cache of STATEMENT_LIST nodes. We create and destroy them + fairly often during gimplification. */ + +static GTY ((deletable (""))) tree stmt_list_cache; + +tree +alloc_stmt_list (void) +{ + tree list = stmt_list_cache; + if (list) + { + stmt_list_cache = TREE_CHAIN (list); + gcc_assert (stmt_list_cache != list); + memset (list, 0, sizeof(struct tree_common)); + TREE_SET_CODE (list, STATEMENT_LIST); + } + else + list = make_node (STATEMENT_LIST); + TREE_TYPE (list) = void_type_node; + return list; +} + +void +free_stmt_list (tree t) +{ + gcc_assert (!STATEMENT_LIST_HEAD (t)); + gcc_assert (!STATEMENT_LIST_TAIL (t)); + /* If this triggers, it's a sign that the same list is being freed + twice. */ + gcc_assert (t != stmt_list_cache || stmt_list_cache == NULL); + TREE_CHAIN (t) = stmt_list_cache; + stmt_list_cache = t; +} + +/* A subroutine of append_to_statement_list{,_force}. T is not NULL. */ + +static void +append_to_statement_list_1 (tree t, tree *list_p) +{ + tree list = *list_p; + tree_stmt_iterator i; + + if (!list) + { + if (t && TREE_CODE (t) == STATEMENT_LIST) + { + *list_p = t; + return; + } + *list_p = list = alloc_stmt_list (); + } + + i = tsi_last (list); + tsi_link_after (&i, t, TSI_CONTINUE_LINKING); +} + +/* Add T to the end of the list container pointed to by LIST_P. + If T is an expression with no effects, it is ignored. */ + +void +append_to_statement_list (tree t, tree *list_p) +{ + if (t && TREE_SIDE_EFFECTS (t)) + append_to_statement_list_1 (t, list_p); +} + +/* Similar, but the statement is always added, regardless of side effects. */ + +void +append_to_statement_list_force (tree t, tree *list_p) +{ + if (t != NULL_TREE) + append_to_statement_list_1 (t, list_p); +} + +/* Links a statement, or a chain of statements, before the current stmt. */ + +void +tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode) +{ + struct tree_statement_list_node *head, *tail, *cur; + + /* Die on looping. */ + gcc_assert (t != i->container); + + if (TREE_CODE (t) == STATEMENT_LIST) + { + head = STATEMENT_LIST_HEAD (t); + tail = STATEMENT_LIST_TAIL (t); + STATEMENT_LIST_HEAD (t) = NULL; + STATEMENT_LIST_TAIL (t) = NULL; + + free_stmt_list (t); + + /* Empty statement lists need no work. */ + if (!head || !tail) + { + gcc_assert (head == tail); + return; + } + } + else + { + head = ggc_alloc_tree_statement_list_node (); + head->prev = NULL; + head->next = NULL; + head->stmt = t; + tail = head; + } + + TREE_SIDE_EFFECTS (i->container) = 1; + + cur = i->ptr; + + /* Link it into the list. */ + if (cur) + { + head->prev = cur->prev; + if (head->prev) + head->prev->next = head; + else + STATEMENT_LIST_HEAD (i->container) = head; + tail->next = cur; + cur->prev = tail; + } + else + { + head->prev = STATEMENT_LIST_TAIL (i->container); + if (head->prev) + head->prev->next = head; + else + STATEMENT_LIST_HEAD (i->container) = head; + STATEMENT_LIST_TAIL (i->container) = tail; + } + + /* Update the iterator, if requested. */ + switch (mode) + { + case TSI_NEW_STMT: + case TSI_CONTINUE_LINKING: + case TSI_CHAIN_START: + i->ptr = head; + break; + case TSI_CHAIN_END: + i->ptr = tail; + break; + case TSI_SAME_STMT: + break; + } +} + +/* Links a statement, or a chain of statements, after the current stmt. */ + +void +tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode) +{ + struct tree_statement_list_node *head, *tail, *cur; + + /* Die on looping. */ + gcc_assert (t != i->container); + + if (TREE_CODE (t) == STATEMENT_LIST) + { + head = STATEMENT_LIST_HEAD (t); + tail = STATEMENT_LIST_TAIL (t); + STATEMENT_LIST_HEAD (t) = NULL; + STATEMENT_LIST_TAIL (t) = NULL; + + free_stmt_list (t); + + /* Empty statement lists need no work. */ + if (!head || !tail) + { + gcc_assert (head == tail); + return; + } + } + else + { + head = ggc_alloc_tree_statement_list_node (); + head->prev = NULL; + head->next = NULL; + head->stmt = t; + tail = head; + } + + TREE_SIDE_EFFECTS (i->container) = 1; + + cur = i->ptr; + + /* Link it into the list. */ + if (cur) + { + tail->next = cur->next; + if (tail->next) + tail->next->prev = tail; + else + STATEMENT_LIST_TAIL (i->container) = tail; + head->prev = cur; + cur->next = head; + } + else + { + gcc_assert (!STATEMENT_LIST_TAIL (i->container)); + STATEMENT_LIST_HEAD (i->container) = head; + STATEMENT_LIST_TAIL (i->container) = tail; + } + + /* Update the iterator, if requested. */ + switch (mode) + { + case TSI_NEW_STMT: + case TSI_CHAIN_START: + i->ptr = head; + break; + case TSI_CONTINUE_LINKING: + case TSI_CHAIN_END: + i->ptr = tail; + break; + case TSI_SAME_STMT: + gcc_assert (cur); + break; + } +} + +/* Remove a stmt from the tree list. The iterator is updated to point to + the next stmt. */ + +void +tsi_delink (tree_stmt_iterator *i) +{ + struct tree_statement_list_node *cur, *next, *prev; + + cur = i->ptr; + next = cur->next; + prev = cur->prev; + + if (prev) + prev->next = next; + else + STATEMENT_LIST_HEAD (i->container) = next; + if (next) + next->prev = prev; + else + STATEMENT_LIST_TAIL (i->container) = prev; + + if (!next && !prev) + TREE_SIDE_EFFECTS (i->container) = 0; + + i->ptr = next; +} + +/* Return the first expression in a sequence of COMPOUND_EXPRs, + or in a STATEMENT_LIST. */ + +tree +expr_first (tree expr) +{ + if (expr == NULL_TREE) + return expr; + + if (TREE_CODE (expr) == STATEMENT_LIST) + { + struct tree_statement_list_node *n = STATEMENT_LIST_HEAD (expr); + return n ? n->stmt : NULL_TREE; + } + + while (TREE_CODE (expr) == COMPOUND_EXPR) + expr = TREE_OPERAND (expr, 0); + + return expr; +} + +/* Return the last expression in a sequence of COMPOUND_EXPRs, + or in a STATEMENT_LIST. */ + +tree +expr_last (tree expr) +{ + if (expr == NULL_TREE) + return expr; + + if (TREE_CODE (expr) == STATEMENT_LIST) + { + struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr); + return n ? n->stmt : NULL_TREE; + } + + while (TREE_CODE (expr) == COMPOUND_EXPR) + expr = TREE_OPERAND (expr, 1); + + return expr; +} + +#include "gt-tree-iterator.h" |