path: root/lib/vasnprintf.c

/* vsprintf with automatic memory allocation.
   This file is intended to provide exactly the same functionality
   as the version in gnulib, but without the need for the xsize module.

   Copyright (C) 1999, 2002-2007 Free Software Foundation, Inc.

   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

/* Tell glibc's <stdio.h> to provide a prototype for snprintf().
   This must come before <config.h> because <config.h> may include
   <features.h>, and once <features.h> has been included, it's too late.  */
#ifndef _GNU_SOURCE
# define _GNU_SOURCE    1
#endif

#include <config.h>
#ifndef IN_LIBINTL
# include <alloca.h>
#endif

/* Specification.  */
#if WIDE_CHAR_VERSION
# include "vasnwprintf.h"
#else
# include "vasnprintf.h"
#endif

#include <stdio.h>	/* snprintf(), sprintf() */
#include <stdlib.h>	/* abort(), malloc(), realloc(), free() */
#include <stdint.h>	/* SIZE_MAX */
#include <string.h>	/* memcpy(), strlen() */
#include <errno.h>	/* errno */
#include <limits.h>	/* CHAR_BIT, INT_MAX */
#include <float.h>	/* DBL_MAX_EXP, LDBL_MAX_EXP */
#if WIDE_CHAR_VERSION
# include "wprintf-parse.h"
#else
# include "printf-parse.h"
#endif

#if HAVE_WCHAR_T
# if HAVE_WCSLEN
#  define local_wcslen wcslen
# else
   /* Solaris 2.5.1 has wcslen() in a separate library libw.so. To avoid
      a dependency towards this library, here is a local substitute.
      Define this substitute only once, even if this file is included
      twice in the same compilation unit.  */
#  ifndef local_wcslen_defined
#   define local_wcslen_defined 1
static size_t
local_wcslen (const wchar_t *s)
{
  const wchar_t *ptr;

  for (ptr = s; *ptr != (wchar_t) 0; ptr++)
    ;
  return ptr - s;
}
#  endif
# endif
#endif

#if WIDE_CHAR_VERSION
# define VASNPRINTF vasnwprintf
# define CHAR_T wchar_t
# define DIRECTIVE wchar_t_directive
# define DIRECTIVES wchar_t_directives
# define PRINTF_PARSE wprintf_parse
# define USE_SNPRINTF 1
# if HAVE_DECL__SNWPRINTF
   /* On Windows, the function swprintf() has a different signature than
      on Unix; we use the _snwprintf() function instead.  */
#  define SNPRINTF _snwprintf
# else
   /* Unix.  */
#  define SNPRINTF swprintf
# endif
#else
# define VASNPRINTF vasnprintf
# define CHAR_T char
# define DIRECTIVE char_directive
# define DIRECTIVES char_directives
# define PRINTF_PARSE printf_parse
# define USE_SNPRINTF (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF)
# if HAVE_DECL__SNPRINTF
   /* Windows.  */
#  define SNPRINTF _snprintf
# else
   /* Unix.  */
#  define SNPRINTF snprintf
# endif
#endif

CHAR_T *
VASNPRINTF (CHAR_T *resultbuf, size_t *lengthp, const CHAR_T *format, va_list args)
{
  DIRECTIVES d;
  arguments a;

  if (PRINTF_PARSE (format, &d, &a) < 0)
    {
      errno = EINVAL;
      return NULL;
    }

#define CLEANUP() \
  free (d.dir);								\
  if (a.arg)								\
    free (a.arg);

  if (printf_fetchargs (args, &a) < 0)
    {
      CLEANUP ();
      errno = EINVAL;
      return NULL;
    }

  {
    size_t buf_neededlength;
    CHAR_T *buf;
    CHAR_T *buf_malloced;
    const CHAR_T *cp;
    size_t i;
    DIRECTIVE *dp;
    /* Output string accumulator.  */
    CHAR_T *result;
    size_t allocated;
    size_t length;

    /* Allocate a small buffer that will hold a directive passed to
       sprintf or snprintf.  */
    buf_neededlength = 7 + d.max_width_length + d.max_precision_length + 6;
#if HAVE_ALLOCA
    if (buf_neededlength < 4000 / sizeof (CHAR_T))
      {
	buf = alloca (buf_neededlength * sizeof (CHAR_T));
	buf_malloced = NULL;
      }
    else
#endif
      {
	if (SIZE_MAX / sizeof (CHAR_T) < buf_neededlength)
	  goto out_of_memory_1;
	buf = (CHAR_T *) malloc (buf_neededlength * sizeof (CHAR_T));
	if (buf == NULL)
	  goto out_of_memory_1;
	buf_malloced = buf;
      }

    if (resultbuf != NULL)
      {
	result = resultbuf;
	allocated = *lengthp;
      }
    else
      {
	result = NULL;
	allocated = 0;
      }
    length = 0;
    /* Invariants:
       result is either == resultbuf or == NULL or malloc-allocated.
       If length > 0, then result != NULL.  */

    /* Ensures that allocated >= length + extra.  Aborts through a jump to
       out_of_memory if size is too big.  */
#define ENSURE_ALLOCATION(extra) \
  {									     \
    size_t needed = length + (extra);					     \
    if (needed < length)						     \
      goto out_of_memory;						     \
    if (needed > allocated)						     \
      {									     \
	size_t memory_size;						     \
	CHAR_T *memory;							     \
									     \
	allocated = (allocated > 0 ? 2 * allocated : 12);		     \
	if (needed > allocated)						     \
	  allocated = needed;						     \
	if (SIZE_MAX / sizeof (CHAR_T) < allocated)			     \
	  goto out_of_memory;						     \
	memory_size = allocated * sizeof (CHAR_T);			     \
	if (result == resultbuf || result == NULL)			     \
	  memory = (CHAR_T *) malloc (memory_size);			     \
	else								     \
	  memory = (CHAR_T *) realloc (result, memory_size);		     \
	if (memory == NULL)						     \
	  goto out_of_memory;						     \
	if (result == resultbuf && length > 0)				     \
	  memcpy (memory, result, length * sizeof (CHAR_T));		     \
	result = memory;						     \
      }									     \
  }

    for (cp = format, i = 0, dp = &d.dir[0]; ; cp = dp->dir_end, i++, dp++)
      {
	if (cp != dp->dir_start)
	  {
	    size_t n = dp->dir_start - cp;

	    ENSURE_ALLOCATION (n);
	    memcpy (result + length, cp, n * sizeof (CHAR_T));
	    length += n;
	  }
	if (i == d.count)
	  break;

	/* Execute a single directive.  */
	if (dp->conversion == '%')
	  {
	    if (!(dp->arg_index == ARG_NONE))
	      abort ();
	    ENSURE_ALLOCATION (1);
	    result[length] = '%';
	    length += 1;
	  }
	else
	  {
	    if (!(dp->arg_index != ARG_NONE))
	      abort ();

	    if (dp->conversion == 'n')
	      {
		switch (a.arg[dp->arg_index].type)
		  {
		  case TYPE_COUNT_SCHAR_POINTER:
		    *a.arg[dp->arg_index].a.a_count_schar_pointer = length;
		    break;
		  case TYPE_COUNT_SHORT_POINTER:
		    *a.arg[dp->arg_index].a.a_count_short_pointer = length;
		    break;
		  case TYPE_COUNT_INT_POINTER:
		    *a.arg[dp->arg_index].a.a_count_int_pointer = length;
		    break;
		  case TYPE_COUNT_LONGINT_POINTER:
		    *a.arg[dp->arg_index].a.a_count_longint_pointer = length;
		    break;
#if HAVE_LONG_LONG_INT
		  case TYPE_COUNT_LONGLONGINT_POINTER:
		    *a.arg[dp->arg_index].a.a_count_longlongint_pointer = length;
		    break;
#endif
		  default:
		    abort ();
		  }
	      }
	    else
	      {
		arg_type type = a.arg[dp->arg_index].type;
		CHAR_T *p;
		unsigned int prefix_count;
		int prefixes[2];
#if !USE_SNPRINTF
		size_t tmp_length;
		CHAR_T tmpbuf[700];
		CHAR_T *tmp;

		/* Allocate a temporary buffer of sufficient size for calling
		   sprintf.  */
		{
		  size_t width;
		  size_t precision;

		  width = 0;
		  if (dp->width_start != dp->width_end)
		    {
		      if (dp->width_arg_index != ARG_NONE)
			{
			  int arg;

			  if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
			    abort ();
			  arg = a.arg[dp->width_arg_index].a.a_int;
			  width = (arg < 0 ? (unsigned int) (-arg) : arg);
			}
		      else
			{
			  const CHAR_T *digitp = dp->width_start;

			  do
			    {
			      size_t w_tmp = width * 10 + (*digitp++ - '0');
			      if (SIZE_MAX / 10 < width || w_tmp < width)
				goto out_of_memory;
			      width = w_tmp;
			    }
			  while (digitp != dp->width_end);
			}
		    }

		  precision = 6;
		  if (dp->precision_start != dp->precision_end)
		    {
		      if (dp->precision_arg_index != ARG_NONE)
			{
			  int arg;

			  if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
			    abort ();
			  arg = a.arg[dp->precision_arg_index].a.a_int;
			  precision = (arg < 0 ? 0 : arg);
			}
		      else
			{
			  const CHAR_T *digitp = dp->precision_start + 1;

			  precision = 0;
			  while (digitp != dp->precision_end)
			    {
			      size_t p1 = 10 * precision + (*digitp++ - '0');
			      precision = ((SIZE_MAX / 10 < precision
					    || p1 < precision)
					   ? SIZE_MAX : p1);
			    }
			}
		    }

		  switch (dp->conversion)
		    {

		    case 'd': case 'i': case 'u':
# if HAVE_LONG_LONG_INT
		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
					  * 0.30103 /* binary -> decimal */
					 )
			  + 1; /* turn floor into ceil */
		      else
# endif
		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
					  * 0.30103 /* binary -> decimal */
					 )
			  + 1; /* turn floor into ceil */
		      else
			tmp_length =
			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
					  * 0.30103 /* binary -> decimal */
					 )
			  + 1; /* turn floor into ceil */
		      if (tmp_length < precision)
			tmp_length = precision;
		      /* Multiply by 2, as an estimate for FLAG_GROUP.  */
		      /* Add 1, to account for a leading sign.  */
		      tmp_length = (tmp_length < SIZE_MAX / 2
				    ? 2 * tmp_length + 1
				    : SIZE_MAX);
		      break;

		    case 'o':
# if HAVE_LONG_LONG_INT
		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
					  * 0.333334 /* binary -> octal */
					 )
			  + 1; /* turn floor into ceil */
		      else
# endif
		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
					  * 0.333334 /* binary -> octal */
					 )
			  + 1; /* turn floor into ceil */
		      else
			tmp_length =
			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
					  * 0.333334 /* binary -> octal */
					 )
			  + 1; /* turn floor into ceil */
		      if (tmp_length < precision)
			tmp_length = precision;
		      /* Add 1, to account for a leading sign.  */
		      tmp_length += (tmp_length < SIZE_MAX);
		      break;

		    case 'x': case 'X':
# if HAVE_LONG_LONG_INT
		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
					  * 0.25 /* binary -> hexadecimal */
					 )
			  + 1; /* turn floor into ceil */
		      else
# endif
		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
					  * 0.25 /* binary -> hexadecimal */
					 )
			  + 1; /* turn floor into ceil */
		      else
			tmp_length =
			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
					  * 0.25 /* binary -> hexadecimal */
					 )
			  + 1; /* turn floor into ceil */
		      if (tmp_length < precision)
			tmp_length = precision;
		      /* Add 2, to account for a leading sign or alternate form.  */
		      tmp_length += 2;
		      if (tmp_length < 2)
			goto out_of_memory;
		      break;

		    case 'f': case 'F':
# if HAVE_LONG_DOUBLE
		      if (type == TYPE_LONGDOUBLE)
			tmp_length =
			  (unsigned int) (LDBL_MAX_EXP
					  * 0.30103 /* binary -> decimal */
					  * 2 /* estimate for FLAG_GROUP */
					 )
			  + 1 /* turn floor into ceil */
			  + 10; /* sign, decimal point etc. */
		      else
# endif
			tmp_length =
			  (unsigned int) (DBL_MAX_EXP
					  * 0.30103 /* binary -> decimal */
					  * 2 /* estimate for FLAG_GROUP */
					 )
			  + 1 /* turn floor into ceil */
			  + 10; /* sign, decimal point etc. */
		      tmp_length += precision;
		      if (tmp_length < precision)
			goto out_of_memory;
		      break;

		    case 'e': case 'E': case 'g': case 'G':
		      tmp_length =
			12; /* sign, decimal point, exponent etc. */
		      tmp_length += precision;
		      if (tmp_length < precision)
			goto out_of_memory;
		      break;

		    case 'a': case 'A':
# if HAVE_LONG_DOUBLE
		      if (type == TYPE_LONGDOUBLE)
			tmp_length =
			  (unsigned int) (LDBL_DIG
					  * 0.831 /* decimal -> hexadecimal */
					 )
			  + 1; /* turn floor into ceil */
		      else
# endif
			tmp_length =
			  (unsigned int) (DBL_DIG
					  * 0.831 /* decimal -> hexadecimal */
					 )
			  + 1; /* turn floor into ceil */
		      if (tmp_length < precision)
			tmp_length = precision;
		      /* Account for sign, decimal point etc. */
		      tmp_length += 12;
		      if (tmp_length < 12)
			goto out_of_memory;
		      break;

		    case 'c':
# if HAVE_WINT_T && !WIDE_CHAR_VERSION
		      if (type == TYPE_WIDE_CHAR)
			tmp_length = MB_CUR_MAX;
		      else
# endif
			tmp_length = 1;
		      break;

		    case 's':
# if HAVE_WCHAR_T
		      if (type == TYPE_WIDE_STRING)
			{
			  tmp_length =
			    local_wcslen (a.arg[dp->arg_index].a.a_wide_string);

#  if !WIDE_CHAR_VERSION
			  if (SIZE_MAX / MB_CUR_MAX < tmp_length)
			    goto out_of_memory;
			  tmp_length *= MB_CUR_MAX;
#  endif
			}
		      else
# endif
			tmp_length = strlen (a.arg[dp->arg_index].a.a_string);
		      break;

		    case 'p':
		      tmp_length =
			(unsigned int) (sizeof (void *) * CHAR_BIT
					* 0.25 /* binary -> hexadecimal */
				       )
			  + 1 /* turn floor into ceil */
			  + 2; /* account for leading 0x */
		      break;

		    default:
		      abort ();
		    }

		  if (tmp_length < width)
		    tmp_length = width;

		  tmp_length++; /* account for trailing NUL */
		  if (!tmp_length)
		    goto out_of_memory;
		}

		if (tmp_length <= sizeof (tmpbuf) / sizeof (CHAR_T))
		  tmp = tmpbuf;
		else
		  {
		    if (SIZE_MAX / sizeof (CHAR_T) < tmp_length)
		      /* Overflow, would lead to out of memory.  */
		      goto out_of_memory;
		    tmp = (CHAR_T *) malloc (tmp_length * sizeof (CHAR_T));
		    if (tmp == NULL)
		      /* Out of memory.  */
		      goto out_of_memory;
		  }
#endif

		/* Construct the format string for calling snprintf or
		   sprintf.  */
		p = buf;
		*p++ = '%';
		if (dp->flags & FLAG_GROUP)
		  *p++ = '\'';
		if (dp->flags & FLAG_LEFT)
		  *p++ = '-';
		if (dp->flags & FLAG_SHOWSIGN)
		  *p++ = '+';
		if (dp->flags & FLAG_SPACE)
		  *p++ = ' ';
		if (dp->flags & FLAG_ALT)
		  *p++ = '#';
		if (dp->flags & FLAG_ZERO)
		  *p++ = '0';
		if (dp->width_start != dp->width_end)
		  {
		    size_t n = dp->width_end - dp->width_start;
		    memcpy (p, dp->width_start, n * sizeof (CHAR_T));
		    p += n;
		  }
		if (dp->precision_start != dp->precision_end)
		  {
		    size_t n = dp->precision_end - dp->precision_start;
		    memcpy (p, dp->precision_start, n * sizeof (CHAR_T));
		    p += n;
		  }

		switch (type)
		  {
#if HAVE_LONG_LONG_INT
		  case TYPE_LONGLONGINT:
		  case TYPE_ULONGLONGINT:
		    *p++ = 'l';
		    /*FALLTHROUGH*/
#endif
		  case TYPE_LONGINT:
		  case TYPE_ULONGINT:
#if HAVE_WINT_T
		  case TYPE_WIDE_CHAR:
#endif
#if HAVE_WCHAR_T
		  case TYPE_WIDE_STRING:
#endif
		    *p++ = 'l';
		    break;
#if HAVE_LONG_DOUBLE
		  case TYPE_LONGDOUBLE:
		    *p++ = 'L';
		    break;
#endif
		  default:
		    break;
		  }
		*p = dp->conversion;
#if USE_SNPRINTF
		p[1] = '%';
		p[2] = 'n';
		p[3] = '\0';
#else
		p[1] = '\0';
#endif

		/* Construct the arguments for calling snprintf or sprintf.  */
		prefix_count = 0;
		if (dp->width_arg_index != ARG_NONE)
		  {
		    if (!(a.arg[dp->width_arg_index].type == TYPE_INT))
		      abort ();
		    prefixes[prefix_count++] = a.arg[dp->width_arg_index].a.a_int;
		  }
		if (dp->precision_arg_index != ARG_NONE)
		  {
		    if (!(a.arg[dp->precision_arg_index].type == TYPE_INT))
		      abort ();
		    prefixes[prefix_count++] = a.arg[dp->precision_arg_index].a.a_int;
		  }

#if USE_SNPRINTF
		/* Prepare checking whether snprintf returns the count
		   via %n.  */
		ENSURE_ALLOCATION (1);
		result[length] = '\0';
#endif

		for (;;)
		  {
		    size_t maxlen;
		    int count;
		    int retcount;

		    maxlen = allocated - length;
		    count = -1;
		    retcount = 0;

#if USE_SNPRINTF
# define SNPRINTF_BUF(arg) \
		    switch (prefix_count)				    \
		      {							    \
		      case 0:						    \
			retcount = SNPRINTF (result + length, maxlen, buf,  \
					     arg, &count);		    \
			break;						    \
		      case 1:						    \
			retcount = SNPRINTF (result + length, maxlen, buf,  \
					     prefixes[0], arg, &count);	    \
			break;						    \
		      case 2:						    \
			retcount = SNPRINTF (result + length, maxlen, buf,  \
					     prefixes[0], prefixes[1], arg, \
					     &count);			    \
			break;						    \
		      default:						    \
			abort ();					    \
		      }
#else
# define SNPRINTF_BUF(arg) \
		    switch (prefix_count)				    \
		      {							    \
		      case 0:						    \
			count = sprintf (tmp, buf, arg);		    \
			break;						    \
		      case 1:						    \
			count = sprintf (tmp, buf, prefixes[0], arg);	    \
			break;						    \
		      case 2:						    \
			count = sprintf (tmp, buf, prefixes[0], prefixes[1],\
					 arg);				    \
			break;						    \
		      default:						    \
			abort ();					    \
		      }
#endif

		    switch (type)
		      {
		      case TYPE_SCHAR:
			{
			  int arg = a.arg[dp->arg_index].a.a_schar;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_UCHAR:
			{
			  unsigned int arg = a.arg[dp->arg_index].a.a_uchar;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_SHORT:
			{
			  int arg = a.arg[dp->arg_index].a.a_short;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_USHORT:
			{
			  unsigned int arg = a.arg[dp->arg_index].a.a_ushort;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_INT:
			{
			  int arg = a.arg[dp->arg_index].a.a_int;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_UINT:
			{
			  unsigned int arg = a.arg[dp->arg_index].a.a_uint;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_LONGINT:
			{
			  long int arg = a.arg[dp->arg_index].a.a_longint;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_ULONGINT:
			{
			  unsigned long int arg = a.arg[dp->arg_index].a.a_ulongint;
			  SNPRINTF_BUF (arg);
			}
			break;
#if HAVE_LONG_LONG_INT
		      case TYPE_LONGLONGINT:
			{
			  long long int arg = a.arg[dp->arg_index].a.a_longlongint;
			  SNPRINTF_BUF (arg);
			}
			break;
		      case TYPE_ULONGLONGINT:
			{
			  unsigned long long int arg = a.arg[dp->arg_index].a.a_ulonglongint;
			  SNPRINTF_BUF (arg);
			}
			break;
#endif
		      case TYPE_DOUBLE:
			{
			  double arg = a.arg[dp->arg_index].a.a_double;
			  SNPRINTF_BUF (arg);
			}
			break;
#if HAVE_LONG_DOUBLE
		      case TYPE_LONGDOUBLE:
			{
			  long double arg = a.arg[dp->arg_index].a.a_longdouble;
			  SNPRINTF_BUF (arg);
			}
			break;
#endif
		      case TYPE_CHAR:
			{
			  int arg = a.arg[dp->arg_index].a.a_char;
			  SNPRINTF_BUF (arg);
			}
			break;
#if HAVE_WINT_T
		      case TYPE_WIDE_CHAR:
			{
			  wint_t arg = a.arg[dp->arg_index].a.a_wide_char;
			  SNPRINTF_BUF (arg);
			}
			break;
#endif
		      case TYPE_STRING:
			{
			  const char *arg = a.arg[dp->arg_index].a.a_string;
			  SNPRINTF_BUF (arg);
			}
			break;
#if HAVE_WCHAR_T
		      case TYPE_WIDE_STRING:
			{
			  const wchar_t *arg = a.arg[dp->arg_index].a.a_wide_string;
			  SNPRINTF_BUF (arg);
			}
			break;
#endif
		      case TYPE_POINTER:
			{
			  void *arg = a.arg[dp->arg_index].a.a_pointer;
			  SNPRINTF_BUF (arg);
			}
			break;
		      default:
			abort ();
		      }

#if USE_SNPRINTF
		    /* Portability: Not all implementations of snprintf()
		       are ISO C 99 compliant.  Determine the number of
		       bytes that snprintf() has produced or would have
		       produced.  */
		    if (count >= 0)
		      {
			/* Verify that snprintf() has NUL-terminated its
			   result.  */
			if (count < maxlen && result[length + count] != '\0')
			  abort ();
			/* Portability hack.  */
			if (retcount > count)
			  count = retcount;
		      }
		    else
		      {
			/* snprintf() doesn't understand the '%n'
			   directive.  */
			if (p[1] != '\0')
			  {
			    /* Don't use the '%n' directive; instead, look
			       at the snprintf() return value.  */
			    p[1] = '\0';
			    continue;
			  }
			else
			  {
			    /* Look at the snprintf() return value.  */
			    if (retcount < 0)
			      {
				/* HP-UX 10.20 snprintf() is doubly deficient:
				   It doesn't understand the '%n' directive,
				   *and* it returns -1 (rather than the length
				   that would have been required) when the
				   buffer is too small.  */
				size_t bigger_need =
				  (allocated > 12 ? allocated : 12);
				ENSURE_ALLOCATION (bigger_need);
				continue;
			      }
			    else
			      count = retcount;
			  }
		      }
#endif

		    /* Attempt to handle failure.  */
		    if (count < 0)
		      {
			if (!(result == resultbuf || result == NULL))
			  free (result);
			if (buf_malloced != NULL)
			  free (buf_malloced);
			CLEANUP ();
			errno = EINVAL;
			return NULL;
		      }

#if !USE_SNPRINTF
		    if (count >= tmp_length)
		      /* tmp_length was incorrectly calculated - fix the
			 code above!  */
		      abort ();
#endif

		    /* Make room for the result.  */
		    if (count >= maxlen)
		      {
			/* Need at least count bytes.  But allocate
			   proportionally, to avoid looping eternally if
			   snprintf() reports a too small count.  */
			ENSURE_ALLOCATION (count < allocated
					   ? allocated : count);
#if USE_SNPRINTF
			continue;
#endif
		      }

#if USE_SNPRINTF
		    /* The snprintf() result did fit.  */
#else
		    /* Append the sprintf() result.  */
		    memcpy (result + length, tmp, count * sizeof (CHAR_T));
		    if (tmp != tmpbuf)
		      free (tmp);
#endif

		    length += count;
		    break;
		  }
	      }
	  }
      }

    /* Add the final NUL.  */
    ENSURE_ALLOCATION (1);
    result[length] = '\0';

    if (result != resultbuf && length + 1 < allocated)
      {
	/* Shrink the allocated memory if possible.  */
	CHAR_T *memory;

	memory = (CHAR_T *) realloc (result, (length + 1) * sizeof (CHAR_T));
	if (memory != NULL)
	  result = memory;
      }

    if (buf_malloced != NULL)
      free (buf_malloced);
    CLEANUP ();
    *lengthp = length;
    if (length > INT_MAX)
      goto length_overflow;
    return result;

  length_overflow:
    /* We could produce such a big string, but its length doesn't fit into
       an 'int'.  POSIX says that snprintf() fails with errno = EOVERFLOW in
       this case.  */
    if (result != resultbuf)
      free (result);
    errno = EOVERFLOW;
    return NULL;

  out_of_memory:
    if (!(result == resultbuf || result == NULL))
      free (result);
    if (buf_malloced != NULL)
      free (buf_malloced);
  out_of_memory_1:
    CLEANUP ();
    errno = ENOMEM;
    return NULL;
  }
}

#undef SNPRINTF
#undef USE_SNPRINTF
#undef PRINTF_PARSE
#undef DIRECTIVES
#undef DIRECTIVE
#undef CHAR_T
#undef VASNPRINTF