[tuples] gimple statement iterators

[Aldy Hernandez <aldyh at redhat dot com>]

Hi Richard.  Hi guys.

How does this look for the sequence iterators?  The extra level of
indirection in PTR is so gsi_stmt_ptr() will work correctly.

??

Aldy

p.s. I'll add the gsi_link_* business, and the rest of the tree-iterator
functionality as needed.

	* gimple-iterator.h: New file.


Index: gimple-iterator.h
===================================================================
--- gimple-iterator.h	(revision 0)
+++ gimple-iterator.h	(revision 0)
@@ -0,0 +1,106 @@
+/* Iterator routines for GIMPLE statements.
+   Copyright (C) 2007 Free Software Foundation, Inc.
+   Contributed by Aldy Hernandez  <aldyh@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, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+#ifndef GCC_SEQ_ITERATOR_H
+#define GCC_SEQ_ITERATOR_H
+
+/* Iterator object for GIMPLE statement sequences.  */
+
+typedef struct {
+    gimple *ptr;
+    gs_seq seq;
+} gimple_stmt_iterator;
+
+/* Return a new iterator initially pointing to GS_SEQ's first statement.  */
+
+static inline gimple_stmt_iterator
+gsi_start (gs_seq seq)
+{
+  gimple_stmt_iterator i;
+
+  i.ptr = &GS_SEQ_FIRST (seq);
+  i.seq = seq;
+
+  return i;
+}
+
+/* Return a new iterator initially pointing to GS_SEQ's last statement.  */
+
+static inline gimple_stmt_iterator
+gsi_last (gs_seq seq)
+{
+  gimple_stmt_iterator i;
+
+  i.ptr = &GS_SEQ_LAST (seq);
+  i.seq = seq;
+
+  return i;
+}
+
+/* Return TRUE if at the end of I.  */
+
+static inline bool
+gsi_end_p (gimple_stmt_iterator i)
+{
+  return *i.ptr == NULL;
+}
+
+/* Return TRUE if we're one statement before the end of I.  */
+
+static inline bool
+gsi_one_before_end_p (gimple_stmt_iterator i)
+{
+  return *i.ptr != NULL && GS_NEXT (*i.ptr) == NULL;
+}
+
+/* Return the next gimple statement in I.  */
+
+static inline void
+gsi_next (gimple_stmt_iterator *i)
+{
+  i->ptr = &GS_NEXT (*i->ptr);
+}
+
+/* Return the previous gimple statement in I.  */
+
+static inline void
+gsi_prev (gimple_stmt_iterator *i)
+{
+  i->ptr = &GS_PREV (*i->ptr);
+}
+
+/* Return a pointer to the current stmt.  */
+
+static inline gimple *
+gsi_stmt_ptr (gimple_stmt_iterator i)
+{
+  return i.ptr;
+}
+
+/* Return the current stmt.  */
+
+static inline gimple
+gsi_stmt (gimple_stmt_iterator i)
+{
+  return *i.ptr;
+}
+
+#endif /* GCC_SEQ_ITERATOR_H */