* stdio-common/printf.h (struct printf_info): Add user element.

New types printf_arginfo_size_function, printf_va_arg_function.
	Declare register_printf_specifier, register_printf_modifier,
	register_printf_type.
	* stdio-common/printf-parse.h (struct printf_spec): Add size element.
	(union printf_arg): Add pa_user element.
	Adjust __printf_arginfo_table type.
	Add __printf_va_arg_table, __printf_modifier_table,
	__handle_registered_modifier_mb, and __handle_registered_modifier_wc
	declarations.
	* stdio-common/printf-parsemb.c: Recognize registered modifiers.
	If registered arginfo call failed try normal specifier.
	* stdio-common/printf-prs.c: Pass additional parameter to arginfo
	function.
	* stdio-common/Makefile (routines): Add reg-modifier and reg-type.
	* stdio-common/Versions: Export register_printf_modifier,
	register_printf_type, and register_printf_specifier for GLIBC_2.10.
	* stdio-common/reg-modifier.c: New file.
	* stdio-common/reg-type.c: New file.
	* stdio-common/reg-printf.c (__register_printf_specifier): New
	function.  Mostly the old __register_printf_function function but
	uses locking and type of third parameter changed.
	(__register_printf_function): Implement using
	__register_printf_specifier.
	* stdio-common/vfprintf.c (vfprintf): Collect argument sizes in
	calls to arginfo functions.  Allocate enough memory for user-defined
	types.  Call new va_arg functions to get user-defined types.
	Try installed handlers even for existing format specifiers first.

stdio-common/reg-modifier.c

@@ -0,0 +1,202 @@
+/* Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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 <errno.h>
+#include <limits.h>
+#include <printf.h>
+#include <wchar.h>
+#include <bits/libc-lock.h>
+
+
+struct printf_modifier_record
+{
+  struct printf_modifier_record *next;
+  int bit;
+  wchar_t str[0];
+};
+
+struct printf_modifier_record **__printf_modifier_table attribute_hidden;
+
+__libc_lock_define_initialized (static, lock)
+
+/* Bits to hand out.  */
+static int next_bit;
+
+
+int
+__register_printf_modifier (wchar_t *str)
+{
+  if (str[0] == L'\0')
+    {
+    einval:
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  wchar_t *wc = str;
+  while (*wc != L'\0')
+    if (*wc < 0 || *wc > (wchar_t) UCHAR_MAX)
+      goto einval;
+    else
+      ++wc;
+
+  if (next_bit / 8 == sizeof (((struct printf_info *) NULL)->user))
+    {
+      __set_errno (ENOSPC);
+      return -1;
+    }
+
+  int result = -1;
+  __libc_lock_lock (lock);
+
+  if (__printf_modifier_table == NULL)
+    {
+      __printf_modifier_table = calloc (UCHAR_MAX,
+					sizeof (*__printf_modifier_table));
+      if (__printf_modifier_table == NULL)
+	goto out;
+    }
+
+  /* Create enough room for the string.  But we don't need the first
+     character. */
+  struct printf_modifier_record *newp = malloc (sizeof (*newp)
+						+ ((wc - str)
+						   * sizeof (wchar_t)));
+  if (newp == NULL)
+    goto out;
+
+  newp->next = __printf_modifier_table[(unsigned char) *str];
+  newp->bit = 1 << next_bit++;
+  wmemcpy (newp->str, str + 1, wc - str);
+
+  __printf_modifier_table[(unsigned char) *str] = newp;
+
+  result = newp->bit;
+
+ out:
+  __libc_lock_unlock (lock);
+
+  return result;
+}
+weak_alias (__register_printf_modifier, register_printf_modifier)
+
+
+#include <stdio.h>
+int
+attribute_hidden
+__handle_registered_modifier_mb (const unsigned char **format,
+				 struct printf_info *info)
+{
+  struct printf_modifier_record *runp = __printf_modifier_table[**format];
+
+  int best_bit = 0;
+  int best_len = 0;
+  const unsigned char *best_cp = NULL;
+
+  while (runp != NULL)
+    {
+      const unsigned char *cp = *format + 1;
+      wchar_t *fcp = runp->str;
+
+      while (*cp != '\0' && *fcp != L'\0')
+	if (*cp != *fcp)
+	  break;
+	else
+	  ++cp, ++fcp;
+
+      if (*fcp == L'\0' && cp - *format > best_len)
+	{
+	  best_cp = cp;
+	  best_len = cp - *format;
+	  best_bit = runp->bit;
+	}
+
+      runp = runp->next;
+    }
+
+  if (best_bit != 0)
+    {
+      info->user |= best_bit;
+      *format = best_cp;
+      return 0;
+    }
+
+  return 1;
+}
+
+
+int
+attribute_hidden
+__handle_registered_modifier_wc (const unsigned int **format,
+				 struct printf_info *info)
+{
+  struct printf_modifier_record *runp = __printf_modifier_table[**format];
+
+  int best_bit = 0;
+  int best_len = 0;
+  const unsigned int *best_cp = NULL;
+
+  while (runp != NULL)
+    {
+      const unsigned int *cp = *format + 1;
+      wchar_t *fcp = runp->str;
+
+      while (*cp != '\0' && *fcp != L'\0')
+	if (*cp != *fcp)
+	  break;
+	else
+	  ++cp, ++fcp;
+
+      if (*fcp == L'\0' && cp - *format > best_len)
+	{
+	  best_cp = cp;
+	  best_len = cp - *format;
+	  best_bit = runp->bit;
+	}
+
+      runp = runp->next;
+    }
+
+  if (best_bit != 0)
+    {
+      info->user |= best_bit;
+      *format = best_cp;
+      return 0;
+    }
+
+  return 1;
+}
+
+
+libc_freeres_fn (free_mem)
+{
+  if (__printf_modifier_table != NULL)
+    {
+      for (int i = 0; i < UCHAR_MAX; ++i)
+	{
+	  struct printf_modifier_record *runp = __printf_modifier_table[i];
+	  while (runp != NULL)
+	    {
+	      struct printf_modifier_record *oldp = runp;
+	      runp = runp->next;
+	      free (oldp);
+	    }
+	}
+      free (__printf_modifier_table);
+    }
+}