--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/stringpool.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,261 @@
+/* String pool for GCC.
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008
+   Free Software Foundation, Inc.
+
+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/>.  */
+
+/* String text, identifier text and identifier node allocator.
+   Identifiers are uniquely stored in a hash table.
+
+   We use cpplib's hash table implementation.  libiberty's
+   hashtab.c is not used because it requires 100% average space
+   overhead per string, which is unacceptable.  Also, this algorithm
+   is faster.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "ggc.h"
+#include "tree.h"
+#include "symtab.h"
+#include "cpplib.h"
+
+/* The "" allocated string.  */
+const char empty_string[] = "";
+
+/* Character strings, each containing a single decimal digit.
+   Written this way to save space.  */
+const char digit_vector[] = {
+  '0', 0, '1', 0, '2', 0, '3', 0, '4', 0,
+  '5', 0, '6', 0, '7', 0, '8', 0, '9', 0
+};
+
+struct ht *ident_hash;
+
+static hashnode alloc_node (hash_table *);
+static int mark_ident (struct cpp_reader *, hashnode, const void *);
+
+static void *
+stringpool_ggc_alloc (size_t x)
+{
+  return ggc_alloc (x);
+}
+
+/* Initialize the string pool.  */
+void
+init_stringpool (void)
+{
+  /* Create with 16K (2^14) entries.  */
+  ident_hash = ht_create (14);
+  ident_hash->alloc_node = alloc_node;
+  ident_hash->alloc_subobject = stringpool_ggc_alloc;
+}
+
+/* Allocate a hash node.  */
+static hashnode
+alloc_node (hash_table *table ATTRIBUTE_UNUSED)
+{
+  return GCC_IDENT_TO_HT_IDENT (make_node (IDENTIFIER_NODE));
+}
+
+/* Allocate and return a string constant of length LENGTH, containing
+   CONTENTS.  If LENGTH is -1, CONTENTS is assumed to be a
+   nul-terminated string, and the length is calculated using strlen.  */
+
+const char *
+ggc_alloc_string (const char *contents, int length)
+{
+  char *result;
+
+  if (length == -1)
+    length = strlen (contents);
+
+  if (length == 0)
+    return empty_string;
+  if (length == 1 && ISDIGIT (contents[0]))
+    return digit_string (contents[0] - '0');
+
+  result = GGC_NEWVAR (char, length + 1);
+  memcpy (result, contents, length);
+  result[length] = '\0';
+  return (const char *) result;
+}
+
+/* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
+   If an identifier with that name has previously been referred to,
+   the same node is returned this time.  */
+
+#undef get_identifier
+
+tree
+get_identifier (const char *text)
+{
+  hashnode ht_node = ht_lookup (ident_hash,
+				(const unsigned char *) text,
+				strlen (text), HT_ALLOC);
+
+  /* ht_node can't be NULL here.  */
+  return HT_IDENT_TO_GCC_IDENT (ht_node);
+}
+
+/* Identical to get_identifier, except that the length is assumed
+   known.  */
+
+tree
+get_identifier_with_length (const char *text, size_t length)
+{
+  hashnode ht_node = ht_lookup (ident_hash,
+				(const unsigned char *) text,
+				length, HT_ALLOC);
+
+  /* ht_node can't be NULL here.  */
+  return HT_IDENT_TO_GCC_IDENT (ht_node);
+}
+
+/* If an identifier with the name TEXT (a null-terminated string) has
+   previously been referred to, return that node; otherwise return
+   NULL_TREE.  */
+
+tree
+maybe_get_identifier (const char *text)
+{
+  hashnode ht_node;
+
+  ht_node = ht_lookup (ident_hash, (const unsigned char *) text,
+		       strlen (text), HT_NO_INSERT);
+  if (ht_node)
+    return HT_IDENT_TO_GCC_IDENT (ht_node);
+
+  return NULL_TREE;
+}
+
+/* Report some basic statistics about the string pool.  */
+
+void
+stringpool_statistics (void)
+{
+  ht_dump_statistics (ident_hash);
+}
+
+/* Mark an identifier for GC.  */
+
+static int
+mark_ident (struct cpp_reader *pfile ATTRIBUTE_UNUSED, hashnode h,
+	    const void *v ATTRIBUTE_UNUSED)
+{
+  gt_ggc_m_9tree_node (HT_IDENT_TO_GCC_IDENT (h));
+  return 1;
+}
+
+/* Return true if an identifier should be removed from the table.  */
+
+static int
+maybe_delete_ident (struct cpp_reader *pfile ATTRIBUTE_UNUSED, hashnode h,
+		    const void *v ATTRIBUTE_UNUSED)
+{
+  return !ggc_marked_p (HT_IDENT_TO_GCC_IDENT (h));
+}
+
+/* Mark the trees hanging off the identifier node for GGC.  These are
+   handled specially (not using gengtype) because identifiers are only
+   roots during one part of compilation.  */
+
+void
+ggc_mark_stringpool (void)
+{
+  ht_forall (ident_hash, mark_ident, NULL);
+}
+
+/* Purge the identifier hash of identifiers which are no longer
+   referenced.  */
+
+void
+ggc_purge_stringpool (void)
+{
+  ht_purge (ident_hash, maybe_delete_ident, NULL);
+}
+
+/* Pointer-walking routine for strings (not very interesting, since
+   strings don't contain pointers).  */
+
+void
+gt_pch_p_S (void *obj ATTRIBUTE_UNUSED, void *x ATTRIBUTE_UNUSED,
+	    gt_pointer_operator op ATTRIBUTE_UNUSED,
+	    void *cookie ATTRIBUTE_UNUSED)
+{
+}
+
+/* PCH pointer-walking routine for strings.  */
+
+void
+gt_pch_n_S (const void *x)
+{
+  gt_pch_note_object (CONST_CAST (void *, x), CONST_CAST (void *, x),
+		      &gt_pch_p_S, gt_types_enum_last);
+}
+
+/* Handle saving and restoring the string pool for PCH.  */
+
+/* SPD is saved in the PCH file and holds the information needed
+   to restore the string pool.  */
+
+struct string_pool_data GTY(())
+{
+  struct ht_identifier * * 
+    GTY((length ("%h.nslots"),
+	 nested_ptr (union tree_node, "%h ? GCC_IDENT_TO_HT_IDENT (%h) : NULL",
+		     "%h ? HT_IDENT_TO_GCC_IDENT (%h) : NULL")))
+    entries;
+  unsigned int nslots;
+  unsigned int nelements;
+};
+
+static GTY(()) struct string_pool_data * spd;
+
+/* Save the stringpool data in SPD.  */
+
+void
+gt_pch_save_stringpool (void)
+{
+  spd = GGC_NEW (struct string_pool_data);
+  spd->nslots = ident_hash->nslots;
+  spd->nelements = ident_hash->nelements;
+  spd->entries = GGC_NEWVEC (struct ht_identifier *, spd->nslots);
+  memcpy (spd->entries, ident_hash->entries,
+	  spd->nslots * sizeof (spd->entries[0]));
+}
+
+/* Return the stringpool to its state before gt_pch_save_stringpool
+   was called.  */
+
+void
+gt_pch_fixup_stringpool (void)
+{
+}
+
+/* A PCH file has been restored, which loaded SPD; fill the real hash table
+   from SPD.  */
+
+void
+gt_pch_restore_stringpool (void)
+{
+  ht_load (ident_hash, spd->entries, spd->nslots, spd->nelements, false);
+  spd = NULL;
+}
+
+#include "gt-stringpool.h"