2012-01-05 Richard Guenther <rguenther@suse.de>

[pf3gnuchains/gcc-fork.git] / gcc / tree-iterator.c

diff --git a/gcc/tree-iterator.c b/gcc/tree-iterator.c
index fabe780..44b6bed 100644 (file)
--- a/gcc/tree-iterator.c
+++ b/gcc/tree-iterator.c
@@ -1,5 +1,6 @@
 /* Iterator routines for manipulating GENERIC and GIMPLE tree statements.
-   Copyright (C) 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
+   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.
@@ -30,17 +31,16 @@ along with GCC; see the file COPYING3.  If not see
 /* This is a cache of STATEMENT_LIST nodes.  We create and destroy them
    fairly often during gimplification.  */
 
-static GTY ((deletable (""))) tree stmt_list_cache;
+static GTY ((deletable (""))) VEC(tree,gc) *stmt_list_cache;
 
 tree
 alloc_stmt_list (void)
 {
-  tree list = stmt_list_cache;
-  if (list)
+  tree list;
+  if (!VEC_empty (tree, stmt_list_cache))
     {
-      stmt_list_cache = TREE_CHAIN (list);
-      gcc_assert (stmt_list_cache != list);
-      memset (list, 0, sizeof(struct tree_common));
+      list = VEC_pop (tree, stmt_list_cache);
+      memset (list, 0, sizeof(struct tree_base));
       TREE_SET_CODE (list, STATEMENT_LIST);
     }
   else
@@ -54,11 +54,48 @@ 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;
+  VEC_safe_push (tree, gc, 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.  */
@@ -89,7 +126,7 @@ tsi_link_before (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
     }
   else
     {
-      head = GGC_NEW (struct tree_statement_list_node);
+      head = ggc_alloc_tree_statement_list_node ();
       head->prev = NULL;
       head->next = NULL;
       head->stmt = t;
@@ -165,7 +202,7 @@ tsi_link_after (tree_stmt_iterator *i, tree t, enum tsi_iterator_update mode)
     }
   else
     {
-      head = GGC_NEW (struct tree_statement_list_node);
+      head = ggc_alloc_tree_statement_list_node ();
       head->prev = NULL;
       head->next = NULL;
       head->stmt = t;
@@ -280,29 +317,4 @@ expr_last (tree expr)
   return expr;
 }
 
-/* If EXPR is a single statement return it.  If EXPR is a
-   STATEMENT_LIST containing exactly one statement S, return S.
-   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"