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Diffstat (limited to 'gcc/tree-iterator.c')
| -rw-r--r-- | gcc/tree-iterator.c | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/gcc/tree-iterator.c b/gcc/tree-iterator.c new file mode 100644 index 00000000000..3f0eb5c9dc3 --- /dev/null +++ b/gcc/tree-iterator.c @@ -0,0 +1,369 @@ +/* Iterator routines for manipulating GENERIC and GIMPLE tree statements. + Copyright (C) 2003, 2004 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 2, 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 COPYING. If not, write to +the Free Software Foundation, 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "tree-simple.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); + TREE_CHAIN (list) = NULL; + TREE_SIDE_EFFECTS (list) = 0; + } + else + { + list = make_node (STATEMENT_LIST); + TREE_TYPE (list) = void_type_node; + } + return list; +} + +void +free_stmt_list (tree t) +{ +#ifdef ENABLE_CHECKING + if (STATEMENT_LIST_HEAD (t) || STATEMENT_LIST_TAIL (t)) + abort (); +#endif + TREE_CHAIN (t) = stmt_list_cache; + stmt_list_cache = t; +} + +/* 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. */ + if (t == i->container) + abort (); + + TREE_SIDE_EFFECTS (i->container) = 1; + + 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) + { + if (head != tail) + abort (); + return; + } + } + else + { + head = ggc_alloc (sizeof (*head)); + head->prev = NULL; + head->next = NULL; + head->stmt = t; + tail = head; + } + + 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 + { + if (STATEMENT_LIST_TAIL (i->container)) + abort (); + 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: + if (!cur) + abort (); + 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. */ + if (t == i->container) + abort (); + + TREE_SIDE_EFFECTS (i->container) = 1; + + 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) + { + if (head != tail) + abort (); + return; + } + } + else + { + head = ggc_alloc (sizeof (*head)); + head->prev = NULL; + head->next = NULL; + head->stmt = t; + tail = head; + } + + 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 + { + if (STATEMENT_LIST_TAIL (i->container)) + abort (); + 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: + if (!cur) + abort (); + 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; +} + +/* Move all statements in the statement list after I to a new + statement list. I itself is unchanged. */ + +tree +tsi_split_statement_list_after (const tree_stmt_iterator *i) +{ + struct tree_statement_list_node *cur, *next; + tree old_sl, new_sl; + + cur = i->ptr; + /* How can we possibly split after the end, or before the beginning? */ + if (cur == NULL) + abort (); + next = cur->next; + + old_sl = i->container; + new_sl = alloc_stmt_list (); + TREE_SIDE_EFFECTS (new_sl) = 1; + + STATEMENT_LIST_HEAD (new_sl) = next; + STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl); + STATEMENT_LIST_TAIL (old_sl) = cur; + cur->next = NULL; + next->prev = NULL; + + return new_sl; +} + +/* Move all statements in the statement list before I to a new + statement list. I is set to the head of the new list. */ + +tree +tsi_split_statement_list_before (tree_stmt_iterator *i) +{ + struct tree_statement_list_node *cur, *prev; + tree old_sl, new_sl; + + cur = i->ptr; + /* How can we possibly split after the end, or before the beginning? */ + if (cur == NULL) + abort (); + prev = cur->prev; + + old_sl = i->container; + new_sl = alloc_stmt_list (); + TREE_SIDE_EFFECTS (new_sl) = 1; + i->container = new_sl; + + STATEMENT_LIST_HEAD (new_sl) = cur; + STATEMENT_LIST_TAIL (new_sl) = STATEMENT_LIST_TAIL (old_sl); + STATEMENT_LIST_TAIL (old_sl) = prev; + cur->prev = NULL; + prev->next = NULL; + + return new_sl; +} + +/* 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; +} + +/* If EXPR is a single statement, naked or in a STATEMENT_LIST, then + return it. Otherwise return NULL. */ + +tree +expr_only (tree expr) +{ + if (expr == NULL_TREE) + return NULL_TREE; + + if (TREE_CODE (expr) == STATEMENT_LIST) + { + struct tree_statement_list_node *n = STATEMENT_LIST_TAIL (expr); + if (n && STATEMENT_LIST_HEAD (expr) == n) + return n->stmt; + else + return NULL_TREE; + } + + if (TREE_CODE (expr) == COMPOUND_EXPR) + return NULL_TREE; + + return expr; +} + +#include "gt-tree-iterator.h" |