Update.

2001-07-22  Ulrich Drepper  <drepper@redhat.com>

	* iconv/gconv_builtin.c (struct builtin_map): Remove init and end
	elements.
	(BUILTIN_TRANSFORMATION): Remove Init and End parameters.
	(__gconv_get_builtin_trans): Initialize __init_fct and __end_fct to
	NULL.
	* iconv/gconv_builtin.h: Remove NULL parameters for Init and End in
	all BUILTIN_TRANSFORMATION calls.
	* iconv/gconv_conf.c (BUILTIN_TRANSFORMATION): Remove Init and End
	parameters.
	* iconv/gconv_simple.c: Likewise.
	* iconv/gconv_db.c (gen_steps): Internal converters don't have
	initializers, move the code accordingly.

	* iconv/gconv_conf.c (__gconv_read_conf): Don't read configuration
	file if STATIC_GCONV is defined.

	* iconv/gconv_conf.c (__gconv_path_envvar): New global variable.
	(__gconv_get_path): Use it instead of call getenv.
	(__gconv_read_conf): First see whether cache can be used.  If yes,
	don't do any work here.
	* iconv/gconv_db.c (__gconv_release_step): Renamed from release_step
	and exported.  Change callers.
	(__gconv_find_transform): First call __gconv_lookup_cache and only
	continue if it signals no cache available.  Remove some unnecessary
	tests.
	* iconv/gconv_int.h: Declare __gconv_path_envvar, __gconv_lookup_cache,
	__gconv_release_step, and __gconv_loaded_cache.
	* iconv/gconv_cache.c: New file.
	* iconv/iconvconfig.c: New file.
	* iconv/iconvconfig.h: New file.
	* iconv/strtab.c: New file.
	* iconv/Makefile: Add rules to build new files and programs.

10 files changed, 2022 insertions, 76 deletions

diff --git a/iconv/Makefile b/iconv/Makefile
index 1e385ca7b9..32fd60497d 100644
--- a/iconv/Makefile
+++ b/iconv/Makefile
@@ -26,11 +26,12 @@ include ../Makeconfig
 headers		= iconv.h gconv.h
 routines	= iconv_open iconv iconv_close \
 		  gconv_open gconv gconv_close gconv_db gconv_conf \
-		  gconv_builtin gconv_simple gconv_trans
+		  gconv_builtin gconv_simple gconv_trans gconv_cache
 ifeq ($(elf),yes)
 routines	+= gconv_dl
 else
 CFLAGS-gconv_db.c = -DSTATIC_GCONV
+CFLAGS-gconv_cache.c = -DSTATIC_GCONV
 CFLAGS-gconv_simple.c = -DSTATIC_GCONV
 endif
 
@@ -38,6 +39,7 @@ vpath %.c ../locale/programs
 
 iconv_prog-modules = iconv_charmap charmap charmap-dir linereader \
 		     dummy-repertoire simple-hash xstrdup xmalloc
+iconvconfig-modules = strtab xmalloc
 extra-objs	   = $(iconv_prog-modules:=.o)
 CFLAGS-iconv_prog.c = -I../locale/programs
 CFLAGS-iconv_charmap.c = -I../locale/programs
@@ -50,10 +52,12 @@ tests	= tst-iconv1 tst-iconv2 tst-iconv3
 distribute	= gconv_builtin.h gconv_int.h loop.c skeleton.c iconv_prog.h \
 		  iconv_charmap.c dummy-repertoire.c gconv_charset.h
 
-others		= iconv_prog
+others		= iconv_prog iconvconfig
 install-others	= $(inst_bindir)/iconv
 
+CFLAGS-gconv_cache.c = -DGCONV_DIR='"$(gconvdir)"'
 CFLAGS-gconv_conf.c = -DGCONV_PATH='"$(gconvdir)"'
+CFLAGS-iconvconfig.c = -DGCONV_PATH='"$(gconvdir)"' -DGCONV_DIR='"$(gconvdir)"'
 
 include ../Rules
 
@@ -61,3 +65,4 @@ $(inst_bindir)/iconv: $(objpfx)iconv_prog $(+force)
 	$(do-install-program)
 
 $(objpfx)iconv_prog: $(iconv_prog-modules:%=$(objpfx)%.o)
+$(objpfx)iconvconfig: $(iconvconfig-modules:%=$(objpfx)%.o)
diff --git a/iconv/gconv_builtin.h b/iconv/gconv_builtin.h
index b4c0c4eea4..86ff6abbc3 100644
--- a/iconv/gconv_builtin.h
+++ b/iconv/gconv_builtin.h
@@ -1,5 +1,5 @@
 /* Builtin transformations.
-   Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -30,18 +30,14 @@ BUILTIN_ALIAS ("OSF00010105//", "ISO-10646/UCS4/") /* level 2 */
 BUILTIN_ALIAS ("OSF00010106//", "ISO-10646/UCS4/") /* level 3 */
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "ISO-10646/UCS4/", 1, "=INTERNAL->ucs4",
-			__gconv_transform_internal_ucs4, NULL, NULL,
-			4, 4, 4, 4)
+			__gconv_transform_internal_ucs4, 4, 4, 4, 4)
 BUILTIN_TRANSFORMATION ("ISO-10646/UCS4/", "INTERNAL", 1, "=ucs4->INTERNAL",
-			__gconv_transform_ucs4_internal, NULL, NULL,
-			4, 4, 4, 4)
+			__gconv_transform_ucs4_internal, 4, 4, 4, 4)
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "UCS-4LE//", 1, "=INTERNAL->ucs4le",
-			__gconv_transform_internal_ucs4le, NULL, NULL,
-			4, 4, 4, 4)
+			__gconv_transform_internal_ucs4le, 4, 4, 4, 4)
 BUILTIN_TRANSFORMATION ("UCS-4LE//", "INTERNAL", 1, "=ucs4le->INTERNAL",
-			__gconv_transform_ucs4le_internal, NULL, NULL,
-			4, 4, 4, 4)
+			__gconv_transform_ucs4le_internal, 4, 4, 4, 4)
 
 BUILTIN_ALIAS ("WCHAR_T//", "INTERNAL")
 
@@ -51,15 +47,12 @@ BUILTIN_ALIAS ("ISO-IR-193//", "ISO-10646/UTF8/")
 BUILTIN_ALIAS ("OSF05010001//", "ISO-10646/UTF8/")
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "ISO-10646/UTF8/", 1, "=INTERNAL->utf8",
-			__gconv_transform_internal_utf8, NULL, NULL,
-			4, 4, 1, 6)
+			__gconv_transform_internal_utf8, 4, 4, 1, 6)
 
 BUILTIN_TRANSFORMATION ("ISO-10646/UTF-8/", "INTERNAL", 1, "=utf8->INTERNAL",
-			__gconv_transform_utf8_internal, NULL, NULL,
-			1, 6, 4, 4)
+			__gconv_transform_utf8_internal, 1, 6, 4, 4)
 BUILTIN_TRANSFORMATION ("ISO-10646/UTF8/", "INTERNAL", 1, "=utf8->INTERNAL",
-			__gconv_transform_utf8_internal, NULL, NULL,
-			1, 6, 4, 4)
+			__gconv_transform_utf8_internal, 1, 6, 4, 4)
 
 BUILTIN_ALIAS ("UCS2//", "ISO-10646/UCS2/")
 BUILTIN_ALIAS ("UCS-2//", "ISO-10646/UCS2/")
@@ -68,12 +61,10 @@ BUILTIN_ALIAS ("OSF00010101//", "ISO-10646/UCS2/") /* level 2 */
 BUILTIN_ALIAS ("OSF00010102//", "ISO-10646/UCS2/") /* level 3 */
 
 BUILTIN_TRANSFORMATION ("ISO-10646/UCS2/", "INTERNAL", 1, "=ucs2->INTERNAL",
-			__gconv_transform_ucs2_internal, NULL, NULL,
-			2, 2, 4, 4)
+			__gconv_transform_ucs2_internal, 2, 2, 4, 4)
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "ISO-10646/UCS2/", 1, "=INTERNAL->ucs2",
-			__gconv_transform_internal_ucs2, NULL, NULL,
-			4, 4, 2, 2)
+			__gconv_transform_internal_ucs2, 4, 4, 2, 2)
 
 
 BUILTIN_ALIAS ("ANSI_X3.4//", "ANSI_X3.4-1968//")
@@ -90,12 +81,10 @@ BUILTIN_ALIAS ("CSASCII//", "ANSI_X3.4-1968//")
 BUILTIN_ALIAS ("OSF00010020//", "ANSI_X3.4-1968//")
 
 BUILTIN_TRANSFORMATION ("ANSI_X3.4-1968//", "INTERNAL", 1, "=ascii->INTERNAL",
-			__gconv_transform_ascii_internal, NULL, NULL,
-			4, 4, 1, 1)
+			__gconv_transform_ascii_internal, 4, 4, 1, 1)
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "ANSI_X3.4-1968//", 1, "=INTERNAL->ascii",
-			__gconv_transform_internal_ascii, NULL, NULL,
-			4, 4, 1, 1)
+			__gconv_transform_internal_ascii, 4, 4, 1, 1)
 
 
 #if BYTE_ORDER == BIG_ENDIAN
@@ -106,13 +95,11 @@ BUILTIN_ALIAS ("UCS-2LE//", "UNICODELITTLE//")
 
 BUILTIN_TRANSFORMATION ("UNICODELITTLE//", "INTERNAL", 1,
 			"=ucs2reverse->INTERNAL",
-			__gconv_transform_ucs2reverse_internal, NULL, NULL,
-			2, 2, 4, 4)
+			__gconv_transform_ucs2reverse_internal, 2, 2, 4, 4)
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "UNICODELITTLE//", 1,
 			"=INTERNAL->ucs2reverse",
-			__gconv_transform_internal_ucs2reverse, NULL, NULL,
-			4, 4, 2, 2)
+			__gconv_transform_internal_ucs2reverse, 4, 4, 2, 2)
 #else
 BUILTIN_ALIAS ("UNICODELITTLE//", "ISO-10646/UCS2/")
 BUILTIN_ALIAS ("UCS-2LE//", "ISO-10646/UCS2/")
@@ -121,11 +108,9 @@ BUILTIN_ALIAS ("UCS-2BE//", "UNICODEBIG//")
 
 BUILTIN_TRANSFORMATION ("UNICODEBIG//", "INTERNAL", 1,
 			"=ucs2reverse->INTERNAL",
-			__gconv_transform_ucs2reverse_internal, NULL, NULL,
-			2, 2, 4, 4)
+			__gconv_transform_ucs2reverse_internal, 2, 2, 4, 4)
 
 BUILTIN_TRANSFORMATION ("INTERNAL", "UNICODEBIG//", 1,
 			"=INTERNAL->ucs2reverse",
-			__gconv_transform_internal_ucs2reverse, NULL, NULL,
-			4, 4, 2, 2)
+			__gconv_transform_internal_ucs2reverse, 4, 4, 2, 2)
 #endif
diff --git a/iconv/gconv_cache.c b/iconv/gconv_cache.c
new file mode 100644
index 0000000000..e204cf1377
--- /dev/null
+++ b/iconv/gconv_cache.c
@@ -0,0 +1,395 @@
+/* Cache handling for iconv modules.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 2001.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#include <gconv_int.h>
+#include <iconvconfig.h>
+
+#include "../intl/hash-string.h"
+
+static void *cache;
+static size_t cache_size;
+static int cache_malloced;
+
+
+int
+internal_function
+__gconv_load_cache (void)
+{
+  int fd;
+  struct stat64 st;
+  struct gconvcache_header *header;
+
+  /* We cannot use the cache if the GCONV_PATH environment variable is
+     set.  */
+  __gconv_path_envvar = getenv ("GCONV_PATH");
+  if (__gconv_path_envvar != NULL)
+    return -1;
+
+  /* See whether the cache file exists.  */
+  fd = __open (GCONV_MODULES_CACHE, O_RDONLY);
+  if (__builtin_expect (fd, 0) == -1)
+    /* Not available.  */
+    return -1;
+
+  /* Get information about the file.  */
+  if (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st), 0) < 0
+      /* We do not have to start looking at the file if it cannot contain
+	 at least the cache header.  */
+      || st.st_size < sizeof (struct gconvcache_header))
+    {
+    close_and_exit:
+      close (fd);
+      return -1;
+    }
+
+  /* Make the file content available.  */
+  cache_size = st.st_size;
+#ifdef _POSIX_MAPPED_FILES
+  cache = __mmap (NULL, cache_size, PROT_READ, MAP_SHARED, fd, 0);
+  if (__builtin_expect (cache == MAP_FAILED, 0))
+#endif
+    {
+      size_t already_read;
+
+      cache = malloc (cache_size);
+      if (cache == NULL)
+	goto close_and_exit;
+
+      already_read = 0;
+      do
+	{
+	  ssize_t n = __read (fd, (char *) cache + already_read,
+			      cache_size - already_read);
+	  if (__builtin_expect (n, 0) == -1)
+	    {
+	      free (cache);
+	      cache = NULL;
+	      goto close_and_exit;
+	    }
+
+	  already_read += n;
+	}
+      while (already_read < cache_size);
+
+      cache_malloced = 1;
+    }
+
+  /* We don't need the file descriptor anymore.  */
+  close (fd);
+
+  /* Check the consistency.  */
+  header = (struct gconvcache_header *) cache;
+  if (__builtin_expect (header->magic, GCONVCACHE_MAGIC) != GCONVCACHE_MAGIC
+      || __builtin_expect (header->string_offset >= cache_size, 0)
+      || __builtin_expect (header->hash_offset >= cache_size, 0)
+      || __builtin_expect (header->hash_size == 0, 0)
+      || __builtin_expect ((header->hash_offset
+			    + header->hash_size * sizeof (struct hash_entry))
+			   > cache_size, 0)
+      || __builtin_expect (header->module_offset >= cache_size, 0)
+      || __builtin_expect (header->otherconv_offset > cache_size, 0))
+    {
+      if (cache_malloced)
+	{
+	  free (cache);
+	  cache_malloced = 0;
+	}
+#ifdef _POSIX_MAPPED_FILES
+      else
+	munmap (cache, cache_size);
+#endif
+      cache = NULL;
+
+      return -1;
+    }
+
+  /* That worked.  */
+  return 0;
+}
+
+
+static int
+internal_function
+find_module_idx (const char *str, size_t *idxp)
+{
+  unsigned int idx;
+  unsigned int hval;
+  unsigned int hval2;
+  const struct gconvcache_header *header;
+  const char *strtab;
+  const struct hash_entry *hashtab;
+  unsigned int limit;
+
+  header = (const struct gconvcache_header *) cache;
+  strtab = (char *) cache + header->string_offset;
+  hashtab = (struct hash_entry *) ((char *) cache + header->hash_offset);
+
+  hval = hash_string (str);
+  idx = hval % header->hash_size;
+  hval2 = 1 + hval % (header->hash_size - 2);
+
+  limit = cache_size - header->string_offset;
+  while (hashtab[idx].string_offset != 0)
+    if (hashtab[idx].string_offset < limit
+	&& strcmp (str, strtab + hashtab[idx].string_offset) == 0)
+      {
+	*idxp = hashtab[idx].module_idx;
+	return 0;
+      }
+    else
+      if ((idx += hval2) >= header->hash_size)
+	idx -= header->hash_size;
+
+  /* Nothing found.  */
+  return -1;
+}
+
+
+static int
+internal_function
+find_module (const char *directory, const char *filename,
+	     struct __gconv_step *result)
+{
+  size_t dirlen = strlen (directory);
+  size_t fnamelen = strlen (filename) + 1;
+  char *fullname;
+  int status = __GCONV_OK;
+
+  fullname = (char *) malloc (dirlen + fnamelen);
+  if (fullname == NULL)
+    return __GCONV_NOMEM;
+
+  memcpy (__mempcpy (fullname, directory, dirlen), filename, fnamelen);
+
+  result->__shlib_handle = __gconv_find_shlib (fullname);
+  if (result->__shlib_handle == NULL)
+    return __GCONV_NOCONV;
+
+  result->__modname = fullname;
+  result->__fct = result->__shlib_handle->fct;
+  result->__init_fct = result->__shlib_handle->init_fct;
+  result->__end_fct = result->__shlib_handle->end_fct;
+  result->__counter = 1;
+
+  result->__data = NULL;
+  if (result->__init_fct != NULL)
+    status = DL_CALL_FCT (result->__init_fct, (result));
+
+  return status;
+}
+
+
+int
+internal_function
+__gconv_lookup_cache (const char *toset, const char *fromset,
+		      struct __gconv_step **handle, size_t *nsteps, int flags)
+{
+  const struct gconvcache_header *header;
+  const char *strtab;
+  size_t fromidx;
+  size_t toidx;
+  const struct module_entry *modtab;
+  const struct module_entry *from_module;
+  const struct module_entry *to_module;
+  struct __gconv_step *result;
+
+  if (cache == NULL)
+    /* We have no cache available.  */
+    return __GCONV_NODB;
+
+  header = (const struct gconvcache_header *) cache;
+  strtab = (char *) cache + header->string_offset;
+  modtab = (const struct module_entry *) ((char *) cache
+					  + header->module_offset);
+
+  if (find_module_idx (fromset, &fromidx) != 0
+      || (header->module_offset + (fromidx + 1) * sizeof (struct module_entry)
+	  > cache_size))
+    return __GCONV_NOCONV;
+  from_module = &modtab[fromidx];
+
+  if (find_module_idx (toset, &toidx) != 0
+      || (header->module_offset + (toidx + 1) * sizeof (struct module_entry)
+	  > cache_size))
+    return __GCONV_NOCONV;
+  to_module = &modtab[toidx];
+
+  /* Avoid copy-only transformations if the user requests.   */
+  if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0) && fromidx == toidx)
+    return __GCONV_NOCONV;
+
+  /* If there are special conversions available examine them first.  */
+  if (__builtin_expect (from_module->extra_offset, 0) != 0)
+    {
+      /* Search through the list to see whether there is a module
+	 matching the destination character set.  */
+      const struct extra_entry *extra;
+
+      /* Note the -1.  This is due to the offset added in iconvconfig.
+	 See there for more explanations.  */
+      extra = (const struct extra_entry *) ((char *) cache
+					    + header->otherconv_offset
+					    + from_module->extra_offset - 1);
+      while (extra->module_cnt != 0
+	     && extra->module[extra->module_cnt - 1].outname_offset != toidx)
+	extra = (const struct extra_entry *) ((char *) extra
+					      + sizeof (struct extra_entry)
+					      + (extra->module_cnt
+						 * sizeof (struct extra_entry_module)));
+
+      if (extra->module_cnt != 0)
+	{
+	  /* Use the extra module.  First determine how many steps.  */
+	  char *fromname;
+	  int idx;
+
+	  *nsteps = extra->module_cnt;
+	  *handle = result =
+	    (struct __gconv_step *) malloc (extra->module_cnt
+					    * sizeof (struct __gconv_step));
+	  if (result == NULL)
+	    return __GCONV_NOMEM;
+
+	  fromname = (char *) strtab + from_module->canonname_offset;
+	  idx = 0;
+	  do
+	    {
+	      result[idx].__from_name = fromname;
+	      fromname = result[idx].__to_name =
+		(char *) strtab + modtab[extra->module[idx].outname_offset].canonname_offset;
+
+#ifndef STATIC_GCONV
+	      if (strtab[extra->module[idx].dir_offset] != '\0')
+		{
+		  /* Load the module, return handle for it.  */
+		  int res;
+
+		  res = find_module (strtab + extra->module[idx].dir_offset,
+				     strtab + extra->module[idx].name_offset,
+				     &result[idx]);
+		  if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
+		    {
+		      /* Something went wrong.  */
+		      free (result);
+		      goto try_internal;
+		    }
+		}
+	      else
+#endif
+		/* It's a builtin transformation.  */
+		__gconv_get_builtin_trans (strtab
+					   + extra->module[idx].name_offset,
+					   &result[idx]);
+
+	    }
+	  while (++idx < extra->module_cnt);
+
+	  return __GCONV_OK;
+	}
+    }
+
+ try_internal:
+  /* See whether we can convert via the INTERNAL charset.  */
+  if (__builtin_expect (from_module->fromname_offset, 1) == 0
+      || __builtin_expect (to_module->toname_offset, 1) == 0)
+    /* Not possible.  Nothing we can do.  */
+    return __GCONV_NOCONV;
+
+  /* Use the two modules.  */
+  result = (struct __gconv_step *) malloc (2 * sizeof (struct __gconv_step));
+  if (result == NULL)
+    return __GCONV_NOMEM;
+
+  *handle = result;
+  *nsteps = 2;
+
+  /* Generate data structure for conversion to INTERNAL.  */
+  result[0].__from_name = (char *) strtab + from_module->canonname_offset;
+  result[0].__to_name = (char *) "INTERNAL";
+
+#ifndef STATIC_GCONV
+  if (strtab[from_module->fromdir_offset] != '\0')
+    {
+      /* Load the module, return handle for it.  */
+      int res = find_module (strtab + from_module->fromdir_offset,
+			     strtab + from_module->fromname_offset,
+			     &result[0]);
+      if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
+	{
+	  /* Something went wrong.  */
+	  free (result);
+	  return res;
+	}
+    }
+  else
+#endif
+    /* It's a builtin transformation.  */
+    __gconv_get_builtin_trans (strtab + from_module->fromname_offset,
+			       &result[0]);
+
+  /* Generate data structure for conversion from INTERNAL.  */
+  result[1].__from_name = (char *) "INTERNAL";
+  result[1].__to_name = (char *) strtab + to_module->canonname_offset;
+
+#ifndef STATIC_GCONV
+  if (strtab[to_module->todir_offset] != '\0')
+    {
+      /* Load the module, return handle for it.  */
+      int res = find_module (strtab + to_module->todir_offset,
+			     strtab + to_module->toname_offset,
+			     &result[1]);
+      if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
+	{
+	  /* Something went wrong.  */
+	  __gconv_release_step (&result[0]);
+	  free (result);
+	  return res;
+	}
+    }
+  else
+#endif
+    /* It's a builtin transformation.  */
+    __gconv_get_builtin_trans (strtab + to_module->toname_offset, &result[1]);
+
+  return __GCONV_OK;
+}
+
+
+/* Free all resources if necessary.  */
+static void __attribute__ ((unused))
+free_mem (void)
+{
+  if (cache_malloced)
+    free (cache);
+#ifdef _POSIX_MAPPED_FILES
+  else
+    munmap (cache, cache_size);
+#endif
+}
+
+text_set_element (__libc_subfreeres, free_mem);
diff --git a/iconv/gconv_conf.c b/iconv/gconv_conf.c
index 9cedbb8406..db5bb476fd 100644
--- a/iconv/gconv_conf.c
+++ b/iconv/gconv_conf.c
@@ -60,8 +60,8 @@ static const char gconv_module_ext[] = MODULE_EXT;
 /* We have a few builtin transformations.  */
 static struct gconv_module builtin_modules[] =
 {
-#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, Init, End, MinF, \
-			       MaxF, MinT, MaxT) \
+#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, MinF, MaxF, \
+			       MinT, MaxT) \
   {									      \
     from_string: From,							      \
     to_string: To,							      \
@@ -79,8 +79,8 @@ static struct gconv_module builtin_modules[] =
 
 static const char *builtin_aliases[] =
 {
-#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, Init, End, MinF, \
-			       MaxF, MinT, MaxT)
+#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, MinF, MaxF, \
+			       MinT, MaxT)
 #define BUILTIN_ALIAS(From, To) From " " To,
 
 #include "gconv_builtin.h"
@@ -92,6 +92,10 @@ static const char *builtin_aliases[] =
 #endif
 
 
+/* Value of the GCONV_PATH environment variable.  */
+const char *__gconv_path_envvar;
+
+
 /* Test whether there is already a matching module known.  */
 static int
 internal_function
@@ -423,7 +427,6 @@ __gconv_get_path (void)
   if (result == NULL)
     {
       /* Determine the complete path first.  */
-      const char *user_path;
       char *gconv_path;
       size_t gconv_path_len;
       char *elem;
@@ -433,8 +436,7 @@ __gconv_get_path (void)
       char *cwd;
       size_t cwdlen;
 
-      user_path = getenv ("GCONV_PATH");
-      if (user_path == NULL)
+      if (__gconv_path_envvar == NULL)
 	{
 	  /* No user-defined path.  Make a modifiable copy of the
 	     default path.  */
@@ -446,11 +448,12 @@ __gconv_get_path (void)
       else
 	{
 	  /* Append the default path to the user-defined path.  */
-	  size_t user_len = strlen (user_path);
+	  size_t user_len = strlen (__gconv_path_envvar);
 
 	  gconv_path_len = user_len + 1 + sizeof (default_gconv_path);
 	  gconv_path = alloca (gconv_path_len);
-	  __mempcpy (__mempcpy (__mempcpy (gconv_path, user_path, user_len),
+	  __mempcpy (__mempcpy (__mempcpy (gconv_path, __gconv_path_envvar,
+					   user_len),
 				":", 1),
 		     default_gconv_path, sizeof (default_gconv_path));
 	  cwd = __getcwd (NULL, 0);
@@ -530,6 +533,15 @@ __gconv_read_conf (void)
   int save_errno = errno;
   size_t cnt;
 
+  /* First see whether we should use the cache.  */
+  if (__gconv_load_cache () == 0)
+    {
+      /* Yes, we are done.  */
+      __set_errno (save_errno);
+      return;
+    }
+
+#ifndef STATIC_GCONV
   /* Find out where we have to look.  */
   if (__gconv_path_elem == NULL)
     __gconv_get_path ();
@@ -549,6 +561,7 @@ __gconv_read_conf (void)
       /* Read the next configuration file.  */
       read_conf_file (filename, elem, elem_len, &modules, &nmodules);
     }
+#endif
 
   /* Add the internal modules.  */
   for (cnt = 0; cnt < sizeof (builtin_modules) / sizeof (builtin_modules[0]);
diff --git a/iconv/gconv_db.c b/iconv/gconv_db.c
index c661c3d472..92b520987b 100644
--- a/iconv/gconv_db.c
+++ b/iconv/gconv_db.c
@@ -178,8 +178,9 @@ free_derivation (void *p)
 
 
 /* Decrement the reference count for a single step in a steps array.  */
-static inline void
-release_step (struct __gconv_step *step)
+void
+internal_function
+__gconv_release_step (struct __gconv_step *step)
 {
   if (--step->__counter == 0)
     {
@@ -231,6 +232,9 @@ gen_steps (struct derivation_step *best, const char *toset,
 					? __strdup (current->result_set)
 					: result[step_cnt + 1].__from_name);
 
+	  result[step_cnt].__counter = 1;
+	  result[step_cnt].__data = NULL;
+
 #ifndef STATIC_GCONV
 	  if (current->code->module_name[0] == '/')
 	    {
@@ -249,6 +253,22 @@ gen_steps (struct derivation_step *best, const char *toset,
 	      result[step_cnt].__fct = shlib_handle->fct;
 	      result[step_cnt].__init_fct = shlib_handle->init_fct;
 	      result[step_cnt].__end_fct = shlib_handle->end_fct;
+
+	      /* Call the init function.  */
+	      if (result[step_cnt].__init_fct != NULL)
+		{
+		  status = DL_CALL_FCT (result[step_cnt].__init_fct,
+					(&result[step_cnt]));
+
+		  if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK)
+		    {
+		      failed = 1;
+		      /* Make sure we unload this modules.  */
+		      --step_cnt;
+		      result[step_cnt].__end_fct = NULL;
+		      break;
+		    }
+		}
 	    }
 	  else
 #endif
@@ -256,25 +276,6 @@ gen_steps (struct derivation_step *best, const char *toset,
 	    __gconv_get_builtin_trans (current->code->module_name,
 				       &result[step_cnt]);
 
-	  result[step_cnt].__counter = 1;
-
-	  /* Call the init function.  */
-	  result[step_cnt].__data = NULL;
-	  if (result[step_cnt].__init_fct != NULL)
-	     {
-	       status = DL_CALL_FCT (result[step_cnt].__init_fct,
-				      (&result[step_cnt]));
-
-	       if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK)
-		 {
-		   failed = 1;
-		   /* Make sure we unload this modules.  */
-		   --step_cnt;
-		   result[step_cnt].__end_fct = NULL;
-		   break;
-		 }
-	     }
-
 	  current = current->last;
 	}
 
@@ -282,7 +283,7 @@ gen_steps (struct derivation_step *best, const char *toset,
 	{
 	  /* Something went wrong while initializing the modules.  */
 	  while (++step_cnt < *nsteps)
-	    release_step (&result[step_cnt]);
+	    __gconv_release_step (&result[step_cnt]);
 	  free (result);
 	  *nsteps = 0;
 	  *handle = NULL;
@@ -328,7 +329,7 @@ increment_counter (struct __gconv_step *steps, size_t nsteps)
 		     (after unloading) and this time loading failed!?  */
 		  --step->__counter;
 		  while (++cnt < nsteps)
-		    release_step (&steps[cnt]);
+		    __gconv_release_step (&steps[cnt]);
 		  result = __GCONV_NOCONV;
 		  break;
 		}
@@ -647,8 +648,8 @@ __gconv_find_transform (const char *toset, const char *fromset,
 			struct __gconv_step **handle, size_t *nsteps,
 			int flags)
 {
-  const char *fromset_expand = NULL;
-  const char *toset_expand = NULL;
+  const char *fromset_expand;
+  const char *toset_expand;
   int result;
 
   /* Ensure that the configuration data is read.  */
@@ -657,6 +658,14 @@ __gconv_find_transform (const char *toset, const char *fromset,
   /* Acquire the lock.  */
   __libc_lock_lock (lock);
 
+  result = __gconv_lookup_cache (toset, fromset, handle, nsteps, flags);
+  if (result != __GCONV_NODB)
+    {
+      /* We have a cache and could resolve the request, successful or not.  */
+      __libc_lock_unlock (lock);
+      return result;
+    }
+
   /* If we don't have a module database return with an error.  */
   if (__gconv_modules_db == NULL)
     {
@@ -665,11 +674,8 @@ __gconv_find_transform (const char *toset, const char *fromset,
     }
 
   /* See whether the names are aliases.  */
-  if (__gconv_alias_db != NULL)
-    {
-      fromset_expand = do_lookup_alias (fromset);
-      toset_expand = do_lookup_alias (toset);
-    }
+  fromset_expand = do_lookup_alias (fromset);
+  toset_expand = do_lookup_alias (toset);
 
   if (__builtin_expect (flags & GCONV_AVOID_NOCONV, 0)
       /* We are not supposed to create a pseudo transformation (means
@@ -713,7 +719,7 @@ __gconv_close_transform (struct __gconv_step *steps, size_t nsteps)
   __libc_lock_lock (lock);
 
   while (nsteps-- > 0)
-    release_step (&steps[nsteps]);
+    __gconv_release_step (&steps[nsteps]);
 
   /* Release the lock.  */
   __libc_lock_unlock (lock);
diff --git a/iconv/gconv_int.h b/iconv/gconv_int.h
index 9641077bcc..c517bd9e97 100644
--- a/iconv/gconv_int.h
+++ b/iconv/gconv_int.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+/* Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
@@ -120,6 +120,9 @@ extern void *__gconv_alias_db;
 extern size_t __gconv_nmodules;
 extern struct gconv_module *__gconv_modules_db;
 
+/* Value of the GCONV_PATH environment variable.  */
+extern const char *__gconv_path_envvar;
+
 
 /* The gconv functions expects the name to be in upper case and complete,
    including the trailing slashes if necessary.  */
@@ -179,9 +182,22 @@ extern int __gconv_find_transform (const char *toset, const char *fromset,
 				   size_t *nsteps, int flags)
      internal_function;
 
+/* Search for transformation in cache data.  */
+extern int __gconv_lookup_cache (const char *toset, const char *fromset,
+				 struct __gconv_step **handle, size_t *nsteps,
+				 int flags)
+     internal_function;
+
+/* Free data associated with a step's structure.  */
+extern void __gconv_release_step (struct __gconv_step *step)
+     internal_function;
+
 /* Read all the configuration data and cache it.  */
 extern void __gconv_read_conf (void);
 
+/* Try to read module cache file.  */
+extern int __gconv_load_cache (void) internal_function;
+
 /* Determine the directories we are looking in.  */
 extern void __gconv_get_path (void);
 
diff --git a/iconv/gconv_simple.c b/iconv/gconv_simple.c
index b0525e5c75..dbec90cb79 100644
--- a/iconv/gconv_simple.c
+++ b/iconv/gconv_simple.c
@@ -30,8 +30,8 @@
 #include <sys/param.h>
 
 #define BUILTIN_ALIAS(s1, s2) /* nothing */
-#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, Init, End, MinF, \
-			       MaxF, MinT, MaxT) \
+#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, MinF, MaxF, \
+			       MinT, MaxT) \
   extern int Fct (struct __gconv_step *, struct __gconv_step_data *,	      \
 		  __const unsigned char **, __const unsigned char *,	      \
 		  unsigned char **, size_t *, int, int);
diff --git a/iconv/iconvconfig.c b/iconv/iconvconfig.c
new file mode 100644
index 0000000000..05b3c9d9a7
--- /dev/null
+++ b/iconv/iconvconfig.c
@@ -0,0 +1,1165 @@
+/* Generate fastloading iconv module configuration files.
+   Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <argp.h>
+#include <assert.h>
+#include <error.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libintl.h>
+#include <locale.h>
+#include <mcheck.h>
+#include <search.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/uio.h>
+
+#include "iconvconfig.h"
+
+/* Get libc version number.  */
+#include "../version.h"
+
+#define PACKAGE _libc_intl_domainname
+
+
+/* The hashing function we use.  */
+#include "../intl/hash-string.h"
+
+
+/* Types used.  */
+struct module
+{
+  char *fromname;
+  struct Strent *fromname_strent;
+  char *filename;
+  struct Strent *filename_strent;
+  const char *directory;
+  struct Strent *directory_strent;
+  struct module *next;
+  int cost;
+  struct Strent *toname_strent;
+  char toname[0];
+};
+
+struct alias
+{
+  char *fromname;
+  struct Strent *froment;
+  struct module *module;
+  struct Strent *toent;
+  char toname[0];
+};
+
+struct name
+{
+  const char *name;
+  struct Strent *strent;
+  int module_idx;
+  uint32_t hashval;
+};
+
+struct name_info
+{
+  const char *canonical_name;
+  struct Strent *canonical_strent;
+
+  struct module *from_internal;
+  struct module *to_internal;
+
+  struct other_conv_list
+  {
+    int dest_idx;
+    struct other_conv
+    {
+      gidx_t module_idx;
+      struct module *module;
+      struct other_conv *next;
+    } other_conv;
+    struct other_conv_list *next;
+  } *other_conv_list;
+};
+
+
+/* Name and version of program.  */
+static void print_version (FILE *stream, struct argp_state *state);
+void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
+
+#define OPT_VERBOSE	1000
+
+/* Definitions of arguments for argp functions.  */
+static const struct argp_option options[] =
+{
+  { "verbose", OPT_VERBOSE, NULL, 0, N_("print progress information") },
+  { NULL, 0, NULL, 0, NULL }
+};
+
+/* Short description of program.  */
+static const char doc[] = N_("\
+Create fastloading iconv module configuration file.");
+
+/* Strings for arguments in help texts.  */
+static const char args_doc[] = N_("[DIR...]");
+
+/* Prototype for option handler.  */
+static error_t parse_opt (int key, char *arg, struct argp_state *state);
+
+/* Function to print some extra text in the help message.  */
+static char *more_help (int key, const char *text, void *input);
+
+/* Data structure to communicate with argp functions.  */
+static struct argp argp =
+{
+  options, parse_opt, args_doc, doc, NULL, more_help
+};
+
+
+/* The function doing the actual work.  */
+static int handle_dir (const char *dir);
+
+/* Add all known builtin conversions and aliases.  */
+static void add_builtins (void);
+
+/* Create list of all aliases without circular aliases.  */
+static void get_aliases (void);
+
+/* Create list of all modules.  */
+static void get_modules (void);
+
+/* Get list of all the names and thereby indexing them.  */
+static void generate_name_list (void);
+
+/* Collect information about all the names.  */
+static void generate_name_info (void);
+
+/* Write the output file.  */
+static int write_output (void);
+
+
+/* Nonzero if verbose ouput is wanted.  */
+static int verbose;
+
+/* Search tree of the modules we know.  */
+static void *modules;
+
+/* Search tree of the aliases we know.  */
+static void *aliases;
+
+/* Search tree for name to index mapping.  */
+static void *names;
+
+/* Number of names we know about.  */
+static int nnames;
+
+/* List of all aliases.  */
+static struct alias **alias_list;
+static size_t nalias_list;
+static size_t nalias_list_max;
+
+/* List of all modules.  */
+static struct module **module_list;
+static size_t nmodule_list;
+static size_t nmodule_list_max;
+
+/* Names and information about them.  */
+static struct name_info *name_info;
+static size_t nname_info;
+
+/* Number of translations not from or to INTERNAL.  */
+static size_t nextra_modules;
+
+
+/* Names and aliases for the builtin transformations.  */
+static struct
+{
+  const char *from;
+  const char *to;
+} builtin_alias[] =
+  {
+#define BUILTIN_ALIAS(alias, real) \
+    { .from = alias, .to = real },
+#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, MinF, MaxF, \
+			       MinT, MaxT)
+#include <gconv_builtin.h>
+  };
+#define nbuiltin_alias (sizeof (builtin_alias) / sizeof (builtin_alias[0]))
+
+static struct
+{
+  const char *from;
+  const char *to;
+  const char *module;
+  int cost;
+} builtin_trans[] =
+  {
+#define BUILTIN_ALIAS(alias, real)
+#define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, MinF, MaxF, \
+			       MinT, MaxT) \
+    { .from = From, .to = To, .module = Name, .cost = Cost },
+#include <gconv_builtin.h>
+  };
+#define nbuiltin_trans (sizeof (builtin_trans) / sizeof (builtin_trans[0]))
+
+
+/* Filename extension for the modules.  */
+#ifndef MODULE_EXT
+# define MODULE_EXT ".so"
+#endif
+static const char gconv_module_ext[] = MODULE_EXT;
+
+
+extern void *xmalloc (size_t n) __attribute__ ((__malloc__));
+extern void *xcalloc (size_t n, size_t m) __attribute__ ((__malloc__));
+extern void *xrealloc (void *p, size_t n);
+
+
+/* C string table handling.  */
+struct Strtab;
+struct Strent;
+
+/* Create new C string table object in memory.  */
+extern struct Strtab *strtabinit (void);
+
+/* Free resources allocated for C string table ST.  */
+extern void strtabfree (struct Strtab *st);
+
+/* Add string STR (length LEN is != 0) to C string table ST.  */
+extern struct Strent *strtabadd (struct Strtab *st, const char *str,
+				 size_t len);
+
+/* Finalize string table ST and store size in *SIZE and return a pointer.  */
+extern void *strtabfinalize (struct Strtab *st, size_t *size);
+
+/* Get offset in string table for string associated with SE.  */
+extern size_t strtaboffset (struct Strent *se);
+
+/* String table we construct.  */
+static struct Strtab *strtab;
+
+
+
+int
+main (int argc, char *argv[])
+{
+  int remaining;
+  int status = 0;
+  char *path;
+  char *tp;
+
+  /* Enable memory use testing.  */
+  mcheck_pedantic (NULL);
+
+  /* Set locale via LC_ALL.  */
+  setlocale (LC_ALL, "");
+
+  /* Set the text message domain.  */
+  textdomain (_libc_intl_domainname);
+
+  /* Parse and process arguments.  */
+  argp_parse (&argp, argc, argv, 0, &remaining, NULL);
+
+  /* Initialize the string table.  */
+  strtab = strtabinit ();
+
+  /* Handle all directories mentioned.  */
+  while (remaining < argc)
+    status |= handle_dir (argv[remaining++]);
+
+  /* In any case also handle the standard directory.  */
+  path = strdupa (GCONV_PATH);
+  tp = strtok (path, ":");
+  while (tp != NULL)
+    {
+      status |= handle_dir (tp);
+
+      tp = strtok (NULL, ":");
+    }
+
+  /* Add the builtin transformations and aliases without overwriting
+     anything.  */
+  add_builtins ();
+
+  /* Store aliases in an array.  */
+  get_aliases ();
+
+  /* Get list of all modules.  */
+  get_modules ();
+
+  /* Generate list of all the names we know to handle in some way.  */
+  generate_name_list ();
+
+  /* Now we know all the names we will handle, collect information
+     about them.  */
+  generate_name_info ();
+
+  /* Write the output file.  */
+  status = write_output ();
+
+  return status;
+}
+
+
+/* Handle program arguments.  */
+static error_t
+parse_opt (int key, char *arg, struct argp_state *state)
+{
+  switch (key)
+    {
+    case OPT_VERBOSE:
+      verbose = 1;
+      break;
+    default:
+      return ARGP_ERR_UNKNOWN;
+    }
+  return 0;
+}
+
+
+static char *
+more_help (int key, const char *text, void *input)
+{
+  switch (key)
+    {
+    case ARGP_KEY_HELP_EXTRA:
+      /* We print some extra information.  */
+      return strdup (gettext ("\
+Report bugs using the `glibcbug' script to <bugs@gnu.org>.\n"));
+    default:
+      break;
+    }
+  return (char *) text;
+}
+
+
+/* Print the version information.  */
+static void
+print_version (FILE *stream, struct argp_state *state)
+{
+  fprintf (stream, "iconvconfig (GNU %s) %s\n", PACKAGE, VERSION);
+  fprintf (stream, gettext ("\
+Copyright (C) %s Free Software Foundation, Inc.\n\
+This is free software; see the source for copying conditions.  There is NO\n\
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
+"), "2001");
+  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
+}
+
+
+static int
+alias_compare (const void *p1, const void *p2)
+{
+  const struct alias *a1 = (const struct alias *) p1;
+  const struct alias *a2 = (const struct alias *) p2;
+
+  return strcmp (a1->fromname, a2->fromname);
+}
+
+
+static void
+new_alias (const char *fromname, size_t fromlen, const char *toname,
+	   size_t tolen)
+{
+  struct alias *newp;
+  void **inserted;
+
+  newp = (struct alias *) xmalloc (sizeof (struct alias) + fromlen + tolen);
+
+  newp->fromname = mempcpy (newp->toname, toname, tolen);
+  memcpy (newp->fromname, fromname, fromlen);
+  newp->module = NULL;
+
+  inserted = (void **) tsearch (newp, &aliases, alias_compare);
+  if (inserted == NULL)
+    error (EXIT_FAILURE, errno, gettext ("while inserting in search tree"));
+  if (*inserted != newp)
+    /* Something went wrong, free this entry.  */
+    free (newp);
+  else
+    {
+      newp->froment = strtabadd (strtab, newp->fromname, fromlen);
+      newp->toent = strtabadd (strtab, newp->toname, tolen);
+    }
+}
+
+
+/* Add new alias.  */
+static void
+add_alias (char *rp)
+{
+  /* We now expect two more string.  The strings are normalized
+     (converted to UPPER case) and strored in the alias database.  */
+  char *from;
+  char *to;
+  char *wp;
+
+  while (isspace (*rp))
+    ++rp;
+  from = wp = rp;
+  while (*rp != '\0' && !isspace (*rp))
+    *wp++ = toupper (*rp++);
+  if (*rp == '\0')
+    /* There is no `to' string on the line.  Ignore it.  */
+    return;
+  *wp++ = '\0';
+  to = ++rp;
+  while (isspace (*rp))
+    ++rp;
+  while (*rp != '\0' && !isspace (*rp))
+    *wp++ = toupper (*rp++);
+  if (to == wp)
+    /* No `to' string, ignore the line.  */
+    return;
+  *wp++ = '\0';
+
+  new_alias (from, to - from, to, wp - to);
+}
+
+
+static void
+append_alias (const void *nodep, VISIT value, int level)
+{
+  if (value != leaf && value != postorder)
+    return;
+
+  if (nalias_list_max == nalias_list)
+    {
+      nalias_list_max += 50;
+      alias_list = (struct alias **) xrealloc (alias_list,
+					       (nalias_list_max
+						* sizeof (struct alias *)));
+    }
+
+  alias_list[nalias_list++] = *(struct alias **) nodep;
+}
+
+
+static void
+get_aliases (void)
+{
+  twalk (aliases, append_alias);
+}
+
+
+static int
+module_compare (const void *p1, const void *p2)
+{
+  const struct module *m1 = (const struct module *) p1;
+  const struct module *m2 = (const struct module *) p2;
+  int result;
+
+  result = strcmp (m1->fromname, m2->fromname);
+  if (result == 0)
+    result = strcmp (m1->toname, m2->toname);
+
+  return result;
+}
+
+
+/* Create new module record.  */
+static void
+new_module (const char *fromname, size_t fromlen, const char *toname,
+	    size_t tolen, const char *directory,
+	    const char *filename, size_t filelen, int cost, size_t need_ext)
+{
+  struct module *new_module;
+  size_t dirlen = strlen (directory) + 1;
+  char *tmp;
+  void **inserted;
+
+  new_module = (struct module *) xmalloc (sizeof (struct module)
+					  + fromlen + tolen + filelen
+					  + need_ext);
+
+  new_module->fromname = mempcpy (new_module->toname, toname, tolen);
+
+  new_module->filename = mempcpy (new_module->fromname, fromname, fromlen);
+
+  new_module->cost = cost;
+  new_module->next = NULL;
+
+  tmp = mempcpy (new_module->filename, filename, filelen);
+  if (need_ext)
+    {
+      memcpy (tmp - 1, gconv_module_ext, sizeof (gconv_module_ext));
+      filelen += sizeof (gconv_module_ext) - 1;
+    }
+  new_module->directory = directory;
+
+  /* Now insert the new module data structure in our search tree.  */
+  inserted = (void **) tsearch (new_module, &modules, module_compare);
+  if (inserted == NULL)
+    error (EXIT_FAILURE, errno, "while inserting in search tree");
+  if (*inserted != new_module)
+    free (new_module);
+  else
+    {
+      new_module->fromname_strent = strtabadd (strtab, new_module->fromname,
+					       fromlen);
+      new_module->toname_strent = strtabadd (strtab, new_module->toname,
+					     tolen);
+      new_module->filename_strent = strtabadd (strtab, new_module->filename,
+					       filelen);
+      new_module->directory_strent = strtabadd (strtab, directory, dirlen);
+    }
+}
+
+
+/* Add new module.  */
+static void
+internal_function
+add_module (char *rp, const char *directory)
+{
+  /* We expect now
+     1. `from' name
+     2. `to' name
+     3. filename of the module
+     4. an optional cost value
+  */
+  char *from;
+  char *to;
+  char *module;
+  char *wp;
+  int need_ext;
+  int cost;
+
+  while (isspace (*rp))
+    ++rp;
+  from = rp;
+  while (*rp != '\0' && !isspace (*rp))
+    {
+      *rp = toupper (*rp);
+      ++rp;
+    }
+  if (*rp == '\0')
+    return;
+  *rp++ = '\0';
+  to = wp = rp;
+  while (isspace (*rp))
+    ++rp;
+  while (*rp != '\0' && !isspace (*rp))
+    *wp++ = toupper (*rp++);
+  if (*rp == '\0')
+    return;
+  *wp++ = '\0';
+  do
+    ++rp;
+  while (isspace (*rp));
+  module = wp;
+  while (*rp != '\0' && !isspace (*rp))
+    *wp++ = *rp++;
+  if (*rp == '\0')
+    {
+      /* There is no cost, use one by default.  */
+      *wp++ = '\0';
+      cost = 1;
+    }
+  else
+    {
+      /* There might be a cost value.  */
+      char *endp;
+
+      *wp++ = '\0';
+      cost = strtol (rp, &endp, 10);
+      if (rp == endp || cost < 1)
+	/* No useful information.  */
+	cost = 1;
+    }
+
+  if (module[0] == '\0')
+    /* No module name given.  */
+    return;
+
+  /* See whether we must add the ending.  */
+  need_ext = 0;
+  if (wp - module < sizeof (gconv_module_ext)
+      || memcmp (wp - sizeof (gconv_module_ext), gconv_module_ext,
+		 sizeof (gconv_module_ext)) != 0)
+    /* We must add the module extension.  */
+    need_ext = sizeof (gconv_module_ext) - 1;
+
+  assert (strlen (from) + 1 == to - from);
+  assert (strlen (to) + 1 == module - to);
+  assert (strlen (module) + 1 == wp - module);
+
+  new_module (from, to - from, to, module - to, directory, module, wp - module,
+	      cost, need_ext);
+}
+
+
+/* Read the config file and add the data for this directory to that.  */
+static int
+handle_dir (const char *dir)
+{
+  char *infile;
+  FILE *fp;
+  char *line = NULL;
+  size_t linelen = 0;
+  size_t dirlen = strlen (dir);
+
+  if (dir[dirlen - 1] != '/')
+    {
+      char *newp = (char *) xmalloc (dirlen + 2);
+      dir = memcpy (newp, dir, dirlen);
+      newp[dirlen++] = '/';
+      newp[dirlen] = '\0';
+    }
+
+  infile = (char *) alloca (dirlen + sizeof "gconv-modules");
+  strcpy (mempcpy (infile, dir, dirlen), "gconv-modules");
+
+  fp = fopen (infile, "r");
+  if (fp == NULL)
+    {
+      error (0, errno, "cannot open `%s'", infile);
+      return 1;
+    }
+
+  /* No threads present.  */
+  __fsetlocking (fp, FSETLOCKING_BYCALLER);
+
+  while (!feof_unlocked (fp))
+    {
+      char *rp, *endp, *word;
+      ssize_t n = __getdelim (&line, &linelen, '\n', fp);
+
+      if (n < 0)
+	/* An error occurred.  */
+	break;
+
+      rp = line;
+      /* Terminate the line (excluding comments or newline) with a NUL
+	 byte to simplify the following code.  */
+      endp = strchr (rp, '#');
+      if (endp != NULL)
+	*endp = '\0';
+      else
+	if (rp[n - 1] == '\n')
+	  rp[n - 1] = '\0';
+
+      while (isspace (*rp))
+	++rp;
+
+      /* If this is an empty line go on with the next one.  */
+      if (rp == endp)
+	continue;
+
+      word = rp;
+      while (*rp != '\0' && !isspace (*rp))
+	++rp;
+
+      if (rp - word == sizeof ("alias") - 1
+	  && memcmp (word, "alias", sizeof ("alias") - 1) == 0)
+	add_alias (rp);
+      else if (rp - word == sizeof ("module") - 1
+	       && memcmp (word, "module", sizeof ("module") - 1) == 0)
+	add_module (rp, dir);
+      /* else */
+	/* Otherwise ignore the line.  */
+    }
+
+  free (line);
+
+  fclose (fp);
+
+  return 0;
+}
+
+
+static void
+append_module (const void *nodep, VISIT value, int level)
+{
+  struct module *mo;
+
+  if (value != leaf && value != postorder)
+    return;
+
+  mo = *(struct module **) nodep;
+
+  if (nmodule_list > 0
+      && strcmp (module_list[nmodule_list - 1]->fromname, mo->fromname) == 0)
+    {
+      /* Same name.  */
+      mo->next = module_list[nmodule_list - 1];
+      module_list[nmodule_list - 1] = mo;
+
+      return;
+    }
+
+  if (nmodule_list_max == nmodule_list)
+    {
+      nmodule_list_max += 50;
+      module_list = (struct module **) xrealloc (module_list,
+						 (nmodule_list_max
+						  * sizeof (struct module *)));
+    }
+
+  module_list[nmodule_list++] = mo;
+}
+
+
+static void
+get_modules (void)
+{
+  twalk (modules, append_module);
+}
+
+
+static void
+add_builtins (void)
+{
+  size_t cnt;
+
+  /* Add all aliases.  */
+  for (cnt = 0; cnt < nbuiltin_alias; ++cnt)
+    new_alias (builtin_alias[cnt].from,
+	       strlen (builtin_alias[cnt].from) + 1,
+	       builtin_alias[cnt].to,
+	       strlen (builtin_alias[cnt].to) + 1);
+
+  /* add the builtin transformations.  */
+  for (cnt = 0; cnt < nbuiltin_trans; ++cnt)
+    new_module (builtin_trans[cnt].from,
+		strlen (builtin_trans[cnt].from) + 1,
+		builtin_trans[cnt].to,
+		strlen (builtin_trans[cnt].to) + 1,
+		"", builtin_trans[cnt].module,
+		strlen (builtin_trans[cnt].module) + 1,
+		builtin_trans[cnt].cost, 0);
+}
+
+
+static int
+name_compare (const void *p1, const void *p2)
+{
+  const struct name *n1 = (const struct name *) p1;
+  const struct name *n2 = (const struct name *) p2;
+
+  return strcmp (n1->name, n2->name);
+}
+
+
+static struct name *
+new_name (const char *str, struct Strent *strent)
+{
+  struct name *newp = (struct name *) xmalloc (sizeof (struct name));
+
+  newp->name = str;
+  newp->strent = strent;
+  newp->module_idx = -1;
+  newp->hashval = hash_string (str);
+
+  ++nnames;
+
+  return newp;
+}
+
+
+static void
+generate_name_list (void)
+{
+  size_t i;
+
+  for (i = 0; i < nmodule_list; ++i)
+    {
+      struct module *runp;
+
+      if (strcmp (module_list[i]->fromname, "INTERNAL") != 0)
+	tsearch (new_name (module_list[i]->fromname,
+			   module_list[i]->fromname_strent),
+		 &names, name_compare);
+
+      for (runp = module_list[i]; runp != NULL; runp = runp->next)
+	if (strcmp (runp->toname, "INTERNAL") != 0)
+	  tsearch (new_name (runp->toname, runp->toname_strent),
+		   &names, name_compare);
+    }
+}
+
+
+static int
+name_to_module_idx (const char *name, int add)
+{
+  struct name **res;
+  struct name fake_name = { .name = name };
+  int idx;
+
+  res = (struct name **) tfind (&fake_name, &names, name_compare);
+  if (res == NULL)
+    abort ();
+
+  idx = (*res)->module_idx;
+  if (idx == -1 && add)
+    /* No module index assigned yet.  */
+    idx = (*res)->module_idx = nname_info++;
+
+  return idx;
+}
+
+
+static void
+generate_name_info (void)
+{
+  size_t i;
+
+  name_info = (struct name_info *) xcalloc (nmodule_list,
+					    sizeof (struct name_info));
+
+  for (i = 0; i < nmodule_list; ++i)
+    {
+      struct module *runp;
+
+      for (runp = module_list[i]; runp != NULL; runp = runp->next)
+	if (strcmp (runp->fromname, "INTERNAL") == 0)
+	  {
+	    int idx = name_to_module_idx (runp->toname, 1);
+	    name_info[idx].from_internal = runp;
+	    assert (name_info[idx].canonical_name == NULL
+		    || strcmp (name_info[idx].canonical_name,
+			       runp->toname) == 0);
+	    name_info[idx].canonical_name = runp->toname;
+	    name_info[idx].canonical_strent = runp->toname_strent;
+	  }
+	else if (strcmp (runp->toname, "INTERNAL") == 0)
+	  {
+	    int idx = name_to_module_idx (runp->fromname, 1);
+	    name_info[idx].to_internal = runp;
+	    assert (name_info[idx].canonical_name == NULL
+		    || strcmp (name_info[idx].canonical_name,
+			       runp->fromname) == 0);
+	    name_info[idx].canonical_name = runp->fromname;
+	    name_info[idx].canonical_strent = runp->fromname_strent;
+	  }
+	else
+	  {
+	    /* This is a transformation not to or from the INTERNAL
+	       encoding.  */
+	    int from_idx = name_to_module_idx (runp->fromname, 1);
+	    int to_idx = name_to_module_idx (runp->toname, 1);
+	    struct other_conv_list *newp;
+
+	    newp = (struct other_conv_list *)
+	      xmalloc (sizeof (struct other_conv_list));
+	    newp->other_conv.module_idx = to_idx;
+	    newp->other_conv.module = runp;
+	    newp->other_conv.next = NULL; /* XXX Allow multiple module sequence */
+	    newp->dest_idx = to_idx;
+	    newp->next = name_info[from_idx].other_conv_list;
+	    name_info[from_idx].other_conv_list = newp;
+	    assert (name_info[from_idx].canonical_name == NULL
+		    || strcmp (name_info[from_idx].canonical_name,
+			       runp->fromname) == 0);
+	    name_info[from_idx].canonical_name = runp->fromname;
+	    name_info[from_idx].canonical_strent = runp->fromname_strent;
+
+	    ++nextra_modules;
+	  }
+    }
+
+  /* Now add the module index information for all the aliases.  */
+  for (i = 0; i < nalias_list; ++i)
+    {
+      struct name fake_name = { .name = alias_list[i]->toname };
+      struct name **tonamep;
+
+      tonamep = (struct name **) tfind (&fake_name, &names, name_compare);
+      if (tonamep != NULL)
+	{
+	  struct name *newp = new_name (alias_list[i]->fromname,
+					alias_list[i]->froment);
+	  newp->module_idx = (*tonamep)->module_idx;
+	  tsearch (newp, &names, name_compare);
+	}
+    }
+}
+
+
+static int
+is_prime (unsigned long int candidate)
+{
+  /* No even number and none less than 10 will be passed here.  */
+  unsigned long int divn = 3;
+  unsigned long int sq = divn * divn;
+
+  while (sq < candidate && candidate % divn != 0)
+    {
+      ++divn;
+      sq += 4 * divn;
+      ++divn;
+    }
+
+  return candidate % divn != 0;
+}
+
+
+static uint32_t
+next_prime (uint32_t seed)
+{
+  /* Make it definitely odd.  */
+  seed |= 1;
+
+  while (!is_prime (seed))
+    seed += 2;
+
+  return seed;
+}
+
+
+/* Format of the output file.
+
+   Offset   Length       Description
+   0000     4            Magic header bytes
+   0004     4            Offset of string table (stoff)
+   0008     4            Offset of name hashing table (hoff)
+   000C     4            Hashing table size (hsize)
+   0010     4            Offset of module table (moff)
+   0014     4            Offset of other conversion module table (ooff)
+
+   stoff    ???          String table
+
+   hoff     8*hsize      Array of tuples
+                            string table offset
+                            module index
+
+   moff     ???          Array of tuples
+                            canonical name offset
+                            from-internal module dir name offset
+                            from-internal module name off
+                            to-internal module dir name offset
+                            to-internal module name offset
+                            offset into other conversion table
+
+   ooff     ???          Sequence of words
+                            name offset
+                            one or more of tuple
+                              canonical name offset
+                              module dir name offset
+                              module name offset
+                            (following last entry canocical name offset is 0)
+*/
+static int
+write_output (void)
+{
+  int fd;
+  char *string_table;
+  size_t string_table_size;
+  struct gconvcache_header header;
+  struct hash_entry *hash_table;
+  size_t hash_size;
+  struct module_entry *module_table;
+  char *extra_table;
+  char *cur_extra_table;
+  size_t n;
+  int idx;
+  struct iovec iov[6];
+  static const gidx_t null_word;
+  size_t total;
+
+  /* Function to insert the names.  */
+  void name_insert (const void *nodep, VISIT value, int level)
+    {
+      struct name *name;
+      unsigned int idx;
+      unsigned int hval2;
+
+      if (value != leaf && value != postorder)
+	return;
+
+      name = *(struct name **) nodep;
+      idx = name->hashval % hash_size;
+      hval2 = 1 + name->hashval % (hash_size - 2);
+
+      while (hash_table[idx].string_offset != 0)
+	if ((idx += hval2) >= hash_size)
+	  idx -= hash_size;
+
+      hash_table[idx].string_offset = strtaboffset (name->strent);
+
+      assert (name->module_idx != -1);
+      hash_table[idx].module_idx = name->module_idx;
+    }
+
+  /* Open the output file.  */
+  fd = open (GCONV_MODULES_CACHE, O_TRUNC | O_CREAT | O_RDWR, 0644);
+  if (fd == -1)
+    return 1;
+
+  /* Create the string table.  */
+  string_table = strtabfinalize (strtab, &string_table_size);
+
+  /* Create the hashing table.  We know how many strings we have.
+     Creating a perfect hash table is not reasonable here.  Therefore
+     we use open hashing and a table size which is the next prime 40%
+     larger than the number of strings.  */
+  hash_size = next_prime (nnames * 1.4);
+  hash_table = (struct hash_entry *) xcalloc (hash_size,
+					      sizeof (struct hash_entry));
+  /* Fill the hash table.  */
+  twalk (names, name_insert);
+
+  /* Create the section for the module list.  */
+  module_table = (struct module_entry *) xcalloc (sizeof (struct module_entry),
+						  nname_info);
+
+  /* Allocate memory for the non-INTERNAL conversions.  The allocated
+     memory can be more than is actually needed.  */
+  extra_table = (char *) xcalloc (sizeof (struct extra_entry)
+				  + sizeof (gidx_t)
+				  + sizeof (struct extra_entry_module),
+				  nextra_modules);
+  cur_extra_table = extra_table;
+
+  /* Fill in the module information.  */
+  for (n = 0; n < nname_info; ++n)
+    {
+      module_table[n].canonname_offset =
+	strtaboffset (name_info[n].canonical_strent);
+
+      if (name_info[n].from_internal == NULL)
+	{
+	  module_table[n].fromdir_offset = 0;
+	  module_table[n].fromname_offset = 0;
+	}
+      else
+	{
+	  module_table[n].fromdir_offset =
+	    strtaboffset (name_info[n].from_internal->directory_strent);
+	  module_table[n].fromname_offset =
+	    strtaboffset (name_info[n].from_internal->filename_strent);
+	}
+
+      if (name_info[n].to_internal == NULL)
+	{
+	  module_table[n].todir_offset = 0;
+	  module_table[n].toname_offset = 0;
+	}
+      else
+	{
+	  module_table[n].todir_offset =
+	    strtaboffset (name_info[n].to_internal->directory_strent);
+	  module_table[n].toname_offset =
+	    strtaboffset (name_info[n].to_internal->filename_strent);
+	}
+
+      if (name_info[n].other_conv_list != NULL)
+	{
+	  struct other_conv_list *other = name_info[n].other_conv_list;
+
+	  /* Store the reference.  We add 1 to distinguish the entry
+	     at offset zero from the case where no extra modules are
+	     available.  The file reader has to account for the
+	     offset.  */
+	  module_table[n].extra_offset = 1 + cur_extra_table - extra_table;
+
+	  do
+	    {
+	      struct other_conv *runp;
+	      struct extra_entry *extra;
+
+	      /* Allocate new entry.  */
+	      extra = (struct extra_entry *) cur_extra_table;
+	      cur_extra_table += sizeof (struct extra_entry);
+	      extra->module_cnt = 0;
+
+	      runp = &other->other_conv;
+	      do
+		{
+		  cur_extra_table += sizeof (struct extra_entry_module);
+		  extra->module[extra->module_cnt].outname_offset =
+		    runp->next == NULL
+		    ? other->dest_idx : runp->next->module_idx;
+		  extra->module[extra->module_cnt].dir_offset =
+		    strtaboffset (runp->module->directory_strent);
+		  extra->module[extra->module_cnt].name_offset =
+		    strtaboffset (runp->module->filename_strent);
+		  ++extra->module_cnt;
+
+		  runp = runp->next;
+		}
+	      while (runp != NULL);
+
+	      other = other->next;
+	    }
+	  while (other != NULL);
+
+	  /* Final module_cnt is zero.  */
+	  *((gidx_t *) cur_extra_table) = 0;
+	  cur_extra_table += sizeof (gidx_t);
+	}
+    }
+
+  header.magic = GCONVCACHE_MAGIC;
+
+  iov[0].iov_base = &header;
+  iov[0].iov_len = sizeof (struct gconvcache_header);
+  total = iov[0].iov_len;
+
+  header.string_offset = total;
+  iov[1].iov_base = string_table;
+  iov[1].iov_len = string_table_size;
+  total += iov[1].iov_len;
+
+  idx = 2;
+  if ((string_table_size & (sizeof (gidx_t) - 1)) != 0)
+    {
+      iov[2].iov_base = (void *) &null_word;
+      iov[2].iov_len = (sizeof (gidx_t)
+			- (string_table_size & (sizeof (gidx_t) - 1)));
+      total += iov[2].iov_len;
+      ++idx;
+    }
+
+  header.hash_offset = total;
+  header.hash_size = hash_size;
+  iov[idx].iov_base = hash_table;
+  iov[idx].iov_len = hash_size * sizeof (struct hash_entry);
+  total += iov[idx].iov_len;
+  ++idx;
+
+  header.module_offset = total;
+  iov[idx].iov_base = module_table;
+  iov[idx].iov_len = nname_info * sizeof (struct module_entry);
+  total += iov[idx].iov_len;
+  ++idx;
+
+  assert (cur_extra_table - extra_table
+	  <= ((sizeof (struct extra_entry) + sizeof (gidx_t)
+	       + sizeof (struct extra_entry_module))
+	      * nextra_modules));
+  header.otherconv_offset = total;
+  iov[idx].iov_base = extra_table;
+  iov[idx].iov_len = cur_extra_table - extra_table;
+  total += iov[idx].iov_len;
+  ++idx;
+
+  if (TEMP_FAILURE_RETRY (writev (fd, iov, idx)) != total)
+    {
+      int save_errno = errno;
+      close (fd);
+      unlink (GCONV_MODULES_CACHE);
+      error (EXIT_FAILURE, save_errno, gettext ("cannot write output file"));
+    }
+
+  close (fd);
+
+  return 0;
+}
diff --git a/iconv/iconvconfig.h b/iconv/iconvconfig.h
new file mode 100644
index 0000000000..c52ceaefe8
--- /dev/null
+++ b/iconv/iconvconfig.h
@@ -0,0 +1,67 @@
+/* Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <stdint.h>
+
+
+typedef uint16_t gidx_t;
+
+
+struct gconvcache_header
+{
+  uint32_t magic;
+  gidx_t string_offset;
+  gidx_t hash_offset;
+  gidx_t hash_size;
+  gidx_t module_offset;
+  gidx_t otherconv_offset;
+};
+
+struct hash_entry
+{
+  gidx_t string_offset;
+  gidx_t module_idx;
+};
+
+struct module_entry
+{
+  gidx_t canonname_offset;
+  gidx_t fromdir_offset;
+  gidx_t fromname_offset;
+  gidx_t todir_offset;
+  gidx_t toname_offset;
+  gidx_t extra_offset;
+};
+
+struct extra_entry
+{
+  gidx_t module_cnt;
+  struct extra_entry_module
+  {
+    gidx_t outname_offset;
+    gidx_t dir_offset;
+    gidx_t name_offset;
+  } module[0];
+};
+
+
+#define GCONVCACHE_MAGIC	0x20010324
+
+
+#define GCONV_MODULES_CACHE	GCONV_DIR "/gconv-modules.cache"
diff --git a/iconv/strtab.c b/iconv/strtab.c
new file mode 100644
index 0000000000..5b3e3283e9
--- /dev/null
+++ b/iconv/strtab.c
@@ -0,0 +1,294 @@
+/* C string table handling.
+   Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+   Written by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+   This program 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.
+
+   This program 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 this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/param.h>
+
+
+struct Strent
+{
+  const char *string;
+  size_t len;
+  struct Strent *next;
+  struct Strent *left;
+  struct Strent *right;
+  size_t offset;
+  char reverse[0];
+};
+
+
+struct memoryblock
+{
+  struct memoryblock *next;
+  char memory[0];
+};
+
+
+struct Strtab
+{
+  struct Strent *root;
+  struct memoryblock *memory;
+  char *backp;
+  size_t left;
+  size_t total;
+
+  struct Strent null;
+};
+
+
+/* Cache for the pagesize.  We correct this value a bit so that `malloc'
+   is not allocating more than a page.  */
+static size_t ps;
+
+
+extern void *xmalloc (size_t n) __attribute__ ((__malloc__));
+
+
+struct Strtab *
+strtabinit (void)
+{
+  if (ps == 0)
+    {
+      ps = sysconf (_SC_PAGESIZE) - 2 * sizeof (void);
+      assert (sizeof (struct memoryblock) < ps);
+    }
+
+  return (struct Strtab *) calloc (1, sizeof (struct Strtab));
+}
+
+
+static void
+morememory (struct Strtab *st, size_t len)
+{
+  struct memoryblock *newmem;
+
+  if (len < ps)
+    len = ps;
+  newmem = (struct memoryblock *) malloc (len);
+  if (newmem == NULL)
+    abort ();
+
+  newmem->next = st->memory;
+  st->memory = newmem;
+  st->backp = newmem->memory;
+  st->left = len;
+}
+
+
+void
+strtabfree (struct Strtab *st)
+{
+  struct memoryblock *mb = st->memory;
+
+  while (mb != NULL)
+    {
+      void *old = mb;
+      mb = mb->next;
+      free (old);
+    }
+
+  free (st);
+}
+
+
+static struct Strent *
+newstring (struct Strtab *st, const char *str, size_t len)
+{
+  struct Strent *newstr;
+  size_t align;
+  int i;
+
+  /* Compute the string length if the caller doesn't know it.  */
+  if (len == 0)
+    len = strlen (str) + 1;
+
+  /* Compute the amount of padding needed to make the structure aligned.  */
+  align = ((__alignof__ (struct Strent)
+	    - (((uintptr_t) st->backp)
+	       & (__alignof__ (struct Strent) - 1)))
+	   & (__alignof__ (struct Strent) - 1));
+
+  /* Make sure there is enough room in the memory block.  */
+  if (st->left < align + sizeof (struct Strent) + len)
+    {
+      morememory (st, sizeof (struct Strent) + len);
+      align = 0;
+    }
+
+  /* Create the reserved string.  */
+  newstr = (struct Strent *) (st->backp + align);
+  newstr->string = str;
+  newstr->len = len;
+  newstr->next = NULL;
+  newstr->left = NULL;
+  newstr->right = NULL;
+  newstr->offset = 0;
+  for (i = len - 2; i >= 0; --i)
+    newstr->reverse[i] = str[len - 2 - i];
+  newstr->reverse[len - 1] = '\0';
+  st->backp += align + sizeof (struct Strent) + len;
+  st->left -= align + sizeof (struct Strent) + len;
+
+  return newstr;
+}
+
+
+/* XXX This function should definitely be rewritten to use a balancing
+   tree algorith (AVL, red-black trees).  For now a simple, correct
+   implementation is enough.  */
+static struct Strent **
+searchstring (struct Strent **sep, struct Strent *newstr)
+{
+  int cmpres;
+
+  /* More strings?  */
+  if (*sep == NULL)
+    {
+      *sep = newstr;
+      return sep;
+    }
+
+  /* Compare the strings.  */
+  cmpres = memcmp ((*sep)->reverse, newstr->reverse,
+		   MIN ((*sep)->len, newstr->len));
+  if (cmpres == 0)
+    /* We found a matching string.  */
+    return sep;
+  else if (cmpres > 0)
+    return searchstring (&(*sep)->left, newstr);
+  else
+    return searchstring (&(*sep)->right, newstr);
+}
+
+
+/* Add new string.  The actual string is assumed to be permanent.  */
+struct Strent *
+strtabadd (struct Strtab *st, const char *str, size_t len)
+{
+  struct Strent *newstr;
+  struct Strent **sep;
+
+  /* Allocate memory for the new string and its associated information.  */
+  newstr = newstring (st, str, len);
+
+  /* Search in the array for the place to insert the string.  If there
+     is no string with matching prefix and no string with matching
+     leading substring, create a new entry.  */
+  sep = searchstring (&st->root, newstr);
+  if (*sep != newstr)
+    {
+      /* This is not the same entry.  This means we have a prefix match.  */
+      if ((*sep)->len > newstr->len)
+	{
+	  /* We have a new substring.  This means we don't need the reverse
+	     string of this entry anymore.  */
+	  st->backp -= newstr->len;
+	  st->left += newstr->len;
+
+	  newstr->next = (*sep)->next;
+	  (*sep)->next = newstr;
+	}
+      else if ((*sep)->len != newstr->len)
+	{
+	  /* When we get here it means that the string we are about to
+	     add has a common prefix with a string we already have but
+	     it is longer.  In this case we have to put it first.  */
+	  newstr->next = *sep;
+	  *sep = newstr;
+
+	  st->total += newstr->len - (*sep)->len;
+	}
+      else
+	{
+	  /* We have an exact match.  Free the memory we allocated.  */
+	  st->left += st->backp - (char *) newstr;
+	  st->backp = (char *) newstr;
+
+	  newstr = *sep;
+	}
+    }
+  else
+    st->total += newstr->len;
+
+  return newstr;
+}
+
+
+static void
+copystrings (struct Strent *nodep, char **freep, size_t *offsetp)
+{
+  struct Strent *subs;
+
+  if (nodep->left != NULL)
+    copystrings (nodep->left, freep, offsetp);
+
+  /* Process the current node.  */
+  nodep->offset = *offsetp;
+  *freep = (char *) mempcpy (*freep, nodep->string, nodep->len);
+  *offsetp += nodep->len;
+
+  for (subs = nodep->next; subs != NULL; subs = subs->next)
+    {
+      assert (subs->len < nodep->len);
+      subs->offset = nodep->offset + nodep->len - subs->len;
+    }
+
+  if (nodep->right != NULL)
+    copystrings (nodep->right, freep, offsetp);
+}
+
+
+void *
+strtabfinalize (struct Strtab *st, size_t *size)
+{
+  size_t copylen;
+  char *endp;
+  char *retval;
+
+  /* Fill in the information.  */
+  endp = retval = (char *) xmalloc (st->total + 1);
+
+  /* Always put an empty string at the beginning so that a zero offset
+     can mean error.  */
+  *endp++ = '\0';
+
+  /* Now run through the tree and add all the string while also updating
+     the offset members of the elfstrent records.  */
+  copylen = 1;
+  copystrings (st->root, &endp, &copylen);
+  assert (copylen == st->total + 1);
+  assert (endp = retval + st->total + 1);
+  *size = copylen;
+
+  return retval;
+}
+
+
+size_t
+strtaboffset (struct Strent *se)
+{
+  return se->offset;
+}