vasnprintf.c

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/* -*- buffer-read-only: t -*- vi: set ro: */
/* DO NOT EDIT! GENERATED AUTOMATICALLY! */
/* vsprintf with automatic memory allocation.
   Copyright (C) 1999, 2002-2008 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 3, 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.  */

/* This file can be parametrized with the following macros:
     VASNPRINTF         The name of the function being defined.
     FCHAR_T            The element type of the format string.
     DCHAR_T            The element type of the destination (result) string.
     FCHAR_T_ONLY_ASCII Set to 1 to enable verification that all characters
                        in the format string are ASCII. MUST be set if
                        FCHAR_T and DCHAR_T are not the same type.
     DIRECTIVE          Structure denoting a format directive.
                        Depends on FCHAR_T.
     DIRECTIVES         Structure denoting the set of format directives of a
                        format string.  Depends on FCHAR_T.
     PRINTF_PARSE       Function that parses a format string.
                        Depends on FCHAR_T.
     DCHAR_CPY          memcpy like function for DCHAR_T[] arrays.
     DCHAR_SET          memset like function for DCHAR_T[] arrays.
     DCHAR_MBSNLEN      mbsnlen like function for DCHAR_T[] arrays.
     SNPRINTF           The system's snprintf (or similar) function.
                        This may be either snprintf or swprintf.
     TCHAR_T            The element type of the argument and result string
                        of the said SNPRINTF function.  This may be either
                        char or wchar_t.  The code exploits that
                        sizeof (TCHAR_T) | sizeof (DCHAR_T) and
                        alignof (TCHAR_T) <= alignof (DCHAR_T).
     DCHAR_IS_TCHAR     Set to 1 if DCHAR_T and TCHAR_T are the same type.
     DCHAR_CONV_FROM_ENCODING A function to convert from char[] to DCHAR[].
     DCHAR_IS_UINT8_T   Set to 1 if DCHAR_T is uint8_t.
     DCHAR_IS_UINT16_T  Set to 1 if DCHAR_T is uint16_t.
     DCHAR_IS_UINT32_T  Set to 1 if DCHAR_T is uint32_t.  */

/* 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

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

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

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

/* Checked size_t computations.  */
#include "xsize.h"

#if (NEED_PRINTF_DOUBLE || NEED_PRINTF_LONG_DOUBLE) && !defined IN_LIBINTL
# include <math.h>
# include "float+.h"
#endif

#if (NEED_PRINTF_DOUBLE || NEED_PRINTF_INFINITE_DOUBLE) && !defined IN_LIBINTL
# include <math.h>
# include "isnand.h"
#endif

#if (NEED_PRINTF_LONG_DOUBLE || NEED_PRINTF_INFINITE_LONG_DOUBLE) && !defined IN_LIBINTL
# include <math.h>
# include "isnanl-nolibm.h"
# include "fpucw.h"
#endif

#if (NEED_PRINTF_DIRECTIVE_A || NEED_PRINTF_DOUBLE) && !defined IN_LIBINTL
# include <math.h>
# include "isnand.h"
# include "printf-frexp.h"
#endif

#if (NEED_PRINTF_DIRECTIVE_A || NEED_PRINTF_LONG_DOUBLE) && !defined IN_LIBINTL
# include <math.h>
# include "isnanl-nolibm.h"
# include "printf-frexpl.h"
# include "fpucw.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

/* Default parameters.  */
#ifndef VASNPRINTF
# if WIDE_CHAR_VERSION
#  define VASNPRINTF vasnwprintf
#  define FCHAR_T wchar_t
#  define DCHAR_T wchar_t
#  define TCHAR_T wchar_t
#  define DCHAR_IS_TCHAR 1
#  define DIRECTIVE wchar_t_directive
#  define DIRECTIVES wchar_t_directives
#  define PRINTF_PARSE wprintf_parse
#  define DCHAR_CPY wmemcpy
# else
#  define VASNPRINTF vasnprintf
#  define FCHAR_T char
#  define DCHAR_T char
#  define TCHAR_T char
#  define DCHAR_IS_TCHAR 1
#  define DIRECTIVE char_directive
#  define DIRECTIVES char_directives
#  define PRINTF_PARSE printf_parse
#  define DCHAR_CPY memcpy
# endif
#endif
#if WIDE_CHAR_VERSION
  /* TCHAR_T is wchar_t.  */
# 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
  /* TCHAR_T is char.  */
# /* Use snprintf if it exists under the name 'snprintf' or '_snprintf'.
     But don't use it on BeOS, since BeOS snprintf produces no output if the
     size argument is >= 0x3000000.  */
# if (HAVE_DECL__SNPRINTF || HAVE_SNPRINTF) && !defined __BEOS__
#  define USE_SNPRINTF 1
# else
#  define USE_SNPRINTF 0
# endif
# if HAVE_DECL__SNPRINTF
   /* Windows.  */
#  define SNPRINTF _snprintf
# else
   /* Unix.  */
#  define SNPRINTF snprintf
   /* Here we need to call the native snprintf, not rpl_snprintf.  */
#  undef snprintf
# endif
#endif
/* Here we need to call the native sprintf, not rpl_sprintf.  */
#undef sprintf

#if (NEED_PRINTF_DIRECTIVE_A || NEED_PRINTF_LONG_DOUBLE || NEED_PRINTF_DOUBLE || NEED_PRINTF_INFINITE_DOUBLE) && !defined IN_LIBINTL
/* Determine the decimal-point character according to the current locale.  */
# ifndef decimal_point_char_defined
#  define decimal_point_char_defined 1
static char
decimal_point_char ()
{
  const char *point;
  /* Determine it in a multithread-safe way.  We know nl_langinfo is
     multithread-safe on glibc systems, but is not required to be multithread-
     safe by POSIX.  sprintf(), however, is multithread-safe.  localeconv()
     is rarely multithread-safe.  */
#  if HAVE_NL_LANGINFO && __GLIBC__
  point = nl_langinfo (RADIXCHAR);
#  elif 1
  char pointbuf[5];
  sprintf (pointbuf, "%#.0f", 1.0);
  point = &pointbuf[1];
#  else
  point = localeconv () -> decimal_point;
#  endif
  /* The decimal point is always a single byte: either '.' or ','.  */
  return (point[0] != '\0' ? point[0] : '.');
}
# endif
#endif

#if NEED_PRINTF_INFINITE_DOUBLE && !NEED_PRINTF_DOUBLE && !defined IN_LIBINTL

/* Equivalent to !isfinite(x) || x == 0, but does not require libm.  */
static int
is_infinite_or_zero (double x)
{
  return isnand (x) || x + x == x;
}

#endif

#if NEED_PRINTF_INFINITE_LONG_DOUBLE && !NEED_PRINTF_LONG_DOUBLE && !defined IN_LIBINTL

/* Equivalent to !isfinite(x), but does not require libm.  */
static int
is_infinitel (long double x)
{
  return isnanl (x) || (x + x == x && x != 0.0L);
}

#endif

#if (NEED_PRINTF_LONG_DOUBLE || NEED_PRINTF_DOUBLE) && !defined IN_LIBINTL

/* Converting 'long double' to decimal without rare rounding bugs requires
   real bignums.  We use the naming conventions of GNU gmp, but vastly simpler
   (and slower) algorithms.  */

typedef unsigned int mp_limb_t;
# define GMP_LIMB_BITS 32
typedef int mp_limb_verify[2 * (sizeof (mp_limb_t) * CHAR_BIT == GMP_LIMB_BITS) - 1];

typedef unsigned long long mp_twolimb_t;
# define GMP_TWOLIMB_BITS 64
typedef int mp_twolimb_verify[2 * (sizeof (mp_twolimb_t) * CHAR_BIT == GMP_TWOLIMB_BITS) - 1];

/* Representation of a bignum >= 0.  */
typedef struct
{
  size_t nlimbs;
  mp_limb_t *limbs; /* Bits in little-endian order, allocated with malloc().  */
} mpn_t;

/* Compute the product of two bignums >= 0.
   Return the allocated memory in case of success, NULL in case of memory
   allocation failure.  */
static void *
multiply (mpn_t src1, mpn_t src2, mpn_t *dest)
{
  const mp_limb_t *p1;
  const mp_limb_t *p2;
  size_t len1;
  size_t len2;

  if (src1.nlimbs <= src2.nlimbs)
    {
      len1 = src1.nlimbs;
      p1 = src1.limbs;
      len2 = src2.nlimbs;
      p2 = src2.limbs;
    }
  else
    {
      len1 = src2.nlimbs;
      p1 = src2.limbs;
      len2 = src1.nlimbs;
      p2 = src1.limbs;
    }
  /* Now 0 <= len1 <= len2.  */
  if (len1 == 0)
    {
      /* src1 or src2 is zero.  */
      dest->nlimbs = 0;
      dest->limbs = (mp_limb_t *) malloc (1);
    }
  else
    {
      /* Here 1 <= len1 <= len2.  */
      size_t dlen;
      mp_limb_t *dp;
      size_t k, i, j;

      dlen = len1 + len2;
      dp = (mp_limb_t *) malloc (dlen * sizeof (mp_limb_t));
      if (dp == NULL)
	return NULL;
      for (k = len2; k > 0; )
	dp[--k] = 0;
      for (i = 0; i < len1; i++)
	{
	  mp_limb_t digit1 = p1[i];
	  mp_twolimb_t carry = 0;
	  for (j = 0; j < len2; j++)
	    {
	      mp_limb_t digit2 = p2[j];
	      carry += (mp_twolimb_t) digit1 * (mp_twolimb_t) digit2;
	      carry += dp[i + j];
	      dp[i + j] = (mp_limb_t) carry;
	      carry = carry >> GMP_LIMB_BITS;
	    }
	  dp[i + len2] = (mp_limb_t) carry;
	}
      /* Normalise.  */
      while (dlen > 0 && dp[dlen - 1] == 0)
	dlen--;
      dest->nlimbs = dlen;
      dest->limbs = dp;
    }
  return dest->limbs;
}

/* Compute the quotient of a bignum a >= 0 and a bignum b > 0.
   a is written as  a = q * b + r  with 0 <= r < b.  q is the quotient, r
   the remainder.
   Finally, round-to-even is performed: If r > b/2 or if r = b/2 and q is odd,
   q is incremented.
   Return the allocated memory in case of success, NULL in case of memory
   allocation failure.  */
static void *
divide (mpn_t a, mpn_t b, mpn_t *q)
{
  /* Algorithm:
     First normalise a and b: a=[a[m-1],...,a[0]], b=[b[n-1],...,b[0]]
     with m>=0 and n>0 (in base beta = 2^GMP_LIMB_BITS).
     If m<n, then q:=0 and r:=a.
     If m>=n=1, perform a single-precision division:
       r:=0, j:=m,
       while j>0 do
         {Here (q[m-1]*beta^(m-1)+...+q[j]*beta^j) * b[0] + r*beta^j =
               = a[m-1]*beta^(m-1)+...+a[j]*beta^j und 0<=r<b[0]<beta}
         j:=j-1, r:=r*beta+a[j], q[j]:=floor(r/b[0]), r:=r-b[0]*q[j].
       Normalise [q[m-1],...,q[0]], yields q.
     If m>=n>1, perform a multiple-precision division:
       We have a/b < beta^(m-n+1).
       s:=intDsize-1-(hightest bit in b[n-1]), 0<=s<intDsize.
       Shift a and b left by s bits, copying them. r:=a.
       r=[r[m],...,r[0]], b=[b[n-1],...,b[0]] with b[n-1]>=beta/2.
       For j=m-n,...,0: {Here 0 <= r < b*beta^(j+1).}
         Compute q* :
           q* := floor((r[j+n]*beta+r[j+n-1])/b[n-1]).
           In case of overflow (q* >= beta) set q* := beta-1.
           Compute c2 := ((r[j+n]*beta+r[j+n-1]) - q* * b[n-1])*beta + r[j+n-2]
           and c3 := b[n-2] * q*.
           {We have 0 <= c2 < 2*beta^2, even 0 <= c2 < beta^2 if no overflow
            occurred.  Furthermore 0 <= c3 < beta^2.
            If there was overflow and
            r[j+n]*beta+r[j+n-1] - q* * b[n-1] >= beta, i.e. c2 >= beta^2,
            the next test can be skipped.}
           While c3 > c2, {Here 0 <= c2 < c3 < beta^2}
             Put q* := q* - 1, c2 := c2 + b[n-1]*beta, c3 := c3 - b[n-2].
           If q* > 0:
             Put r := r - b * q* * beta^j. In detail:
               [r[n+j],...,r[j]] := [r[n+j],...,r[j]] - q* * [b[n-1],...,b[0]].
               hence: u:=0, for i:=0 to n-1 do
                              u := u + q* * b[i],
                              r[j+i]:=r[j+i]-(u mod beta) (+ beta, if carry),
                              u:=u div beta (+ 1, if carry in subtraction)
                      r[n+j]:=r[n+j]-u.
               {Since always u = (q* * [b[i-1],...,b[0]] div beta^i) + 1
                               < q* + 1 <= beta,
                the carry u does not overflow.}
             If a negative carry occurs, put q* := q* - 1
               and [r[n+j],...,r[j]] := [r[n+j],...,r[j]] + [0,b[n-1],...,b[0]].
         Set q[j] := q*.
       Normalise [q[m-n],..,q[0]]; this yields the quotient q.
       Shift [r[n-1],...,r[0]] right by s bits and normalise; this yields the
       rest r.
       The room for q[j] can be allocated at the memory location of r[n+j].
     Finally, round-to-even:
       Shift r left by 1 bit.
       If r > b or if r = b and q[0] is odd, q := q+1.
   */
  const mp_limb_t *a_ptr = a.limbs;
  size_t a_len = a.nlimbs;
  const mp_limb_t *b_ptr = b.limbs;
  size_t b_len = b.nlimbs;
  mp_limb_t *roomptr;
  mp_limb_t *tmp_roomptr = NULL;
  mp_limb_t *q_ptr;
  size_t q_len;
  mp_limb_t *r_ptr;
  size_t r_len;

  /* Allocate room for a_len+2 digits.
     (Need a_len+1 digits for the real division and 1 more digit for the
     final rounding of q.)  */
  roomptr = (mp_limb_t *) malloc ((a_len + 2) * sizeof (mp_limb_t));
  if (roomptr == NULL)
    return NULL;

  /* Normalise a.  */
  while (a_len > 0 && a_ptr[a_len - 1] == 0)
    a_len--;

  /* Normalise b.  */
  for (;;)
    {
      if (b_len == 0)
	/* Division by zero.  */
	abort ();
      if (b_ptr[b_len - 1] == 0)
	b_len--;
      else
	break;
    }

  /* Here m = a_len >= 0 and n = b_len > 0.  */

  if (a_len < b_len)
    {
      /* m<n: trivial case.  q=0, r := copy of a.  */
      r_ptr = roomptr;
      r_len = a_len;
      memcpy (r_ptr, a_ptr, a_len * sizeof (mp_limb_t));
      q_ptr = roomptr + a_len;
      q_len = 0;
    }
  else if (b_len == 1)
    {
      /* n=1: single precision division.
	 beta^(m-1) <= a < beta^m  ==>  beta^(m-2) <= a/b < beta^m  */
      r_ptr = roomptr;
      q_ptr = roomptr + 1;
      {
	mp_limb_t den = b_ptr[0];
	mp_limb_t remainder = 0;
	const mp_limb_t *sourceptr = a_ptr + a_len;
	mp_limb_t *destptr = q_ptr + a_len;
	size_t count;
	for (count = a_len; count > 0; count--)
	  {
	    mp_twolimb_t num =
	      ((mp_twolimb_t) remainder << GMP_LIMB_BITS) | *--sourceptr;
	    *--destptr = num / den;
	    remainder = num % den;
	  }
	/* Normalise and store r.  */
	if (remainder > 0)
	  {
	    r_ptr[0] = remainder;
	    r_len = 1;
	  }
	else
	  r_len = 0;
	/* Normalise q.  */
	q_len = a_len;
	if (q_ptr[q_len - 1] == 0)
	  q_len--;
      }
    }
  else
    {
      /* n>1: multiple precision division.
	 beta^(m-1) <= a < beta^m, beta^(n-1) <= b < beta^n  ==>
	 beta^(m-n-1) <= a/b < beta^(m-n+1).  */
      /* Determine s.  */
      size_t s;
      {
	mp_limb_t msd = b_ptr[b_len - 1]; /* = b[n-1], > 0 */
	s = 31;
	if (msd >= 0x10000)
	  {
	    msd = msd >> 16;
	    s -= 16;
	  }
	if (msd >= 0x100)
	  {
	    msd = msd >> 8;
	    s -= 8;
	  }
	if (msd >= 0x10)
	  {
	    msd = msd >> 4;
	    s -= 4;
	  }
	if (msd >= 0x4)
	  {
	    msd = msd >> 2;