vasnprintf.c

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/* vsprintf with automatic memory allocation.
   Copyright (C) 1999, 2002-2005 Free Software Foundation, Inc.

   This program 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, 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library 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

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#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 <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

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

/* Some systems, like OSF/1 4.0 and Woe32, don't have EOVERFLOW.  */
#ifndef EOVERFLOW
# define EOVERFLOW E2BIG
#endif

#ifdef HAVE_WCHAR_T
# ifdef 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 =
      xsum4 (7, d.max_width_length, d.max_precision_length, 6);
#if HAVE_ALLOCA
    if (buf_neededlength < 4000 / sizeof (CHAR_T))
      {
	buf = (CHAR_T *) alloca (buf_neededlength * sizeof (CHAR_T));
	buf_malloced = NULL;
      }
    else
#endif
      {
	size_t buf_memsize = xtimes (buf_neededlength, sizeof (CHAR_T));
	if (size_overflow_p (buf_memsize))
	  goto out_of_memory_1;
	buf = (CHAR_T *) malloc (buf_memsize);
	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 >= needed.  Aborts through a jump to
       out_of_memory if needed is SIZE_MAX or otherwise too big.  */
#define ENSURE_ALLOCATION(needed) \
    if ((needed) > allocated)						     \
      {									     \
	size_t memory_size;						     \
	CHAR_T *memory;							     \
									     \
	allocated = (allocated > 0 ? xtimes (allocated, 2) : 12);	     \
	if ((needed) > allocated)					     \
	  allocated = (needed);						     \
	memory_size = xtimes (allocated, sizeof (CHAR_T));		     \
	if (size_overflow_p (memory_size))				     \
	  goto out_of_memory;						     \
	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;
	    size_t augmented_length = xsum (length, n);

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

	/* Execute a single directive.  */
	if (dp->conversion == '%')
	  {
	    size_t augmented_length;

	    if (!(dp->arg_index == ARG_NONE))
	      abort ();
	    augmented_length = xsum (length, 1);
	    ENSURE_ALLOCATION (augmented_length);
	    result[length] = '%';
	    length = augmented_length;
	  }
	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;
#ifdef HAVE_LONG_LONG
		  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
			    width = xsum (xtimes (width, 10), *digitp++ - '0');
			  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)
			    precision = xsum (xtimes (precision, 10), *digitp++ - '0');
			}
		    }

		  switch (dp->conversion)
		    {

		    case 'd': case 'i': case 'u':
# ifdef HAVE_LONG_LONG
		      if (type == TYPE_LONGLONGINT || type == TYPE_ULONGLONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long long) * CHAR_BIT
					  * 0.30103 /* binary -> decimal */
					  * 2 /* estimate for FLAG_GROUP */
					 )
			  + 1 /* turn floor into ceil */
			  + 1; /* account for leading sign */
		      else
# endif
		      if (type == TYPE_LONGINT || type == TYPE_ULONGINT)
			tmp_length =
			  (unsigned int) (sizeof (unsigned long) * CHAR_BIT
					  * 0.30103 /* binary -> decimal */
					  * 2 /* estimate for FLAG_GROUP */
					 )
			  + 1 /* turn floor into ceil */
			  + 1; /* account for leading sign */
		      else
			tmp_length =
			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
					  * 0.30103 /* binary -> decimal */
					  * 2 /* estimate for FLAG_GROUP */
					 )
			  + 1 /* turn floor into ceil */
			  + 1; /* account for leading sign */
		      break;

		    case 'o':
# ifdef HAVE_LONG_LONG
		      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 */
			  + 1; /* account for leading sign */
		      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 */
			  + 1; /* account for leading sign */
		      else
			tmp_length =
			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
					  * 0.333334 /* binary -> octal */
					 )
			  + 1 /* turn floor into ceil */
			  + 1; /* account for leading sign */
		      break;

		    case 'x': case 'X':
# ifdef HAVE_LONG_LONG
		      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 */
			  + 2; /* account for leading sign or alternate form */
		      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 */
			  + 2; /* account for leading sign or alternate form */
		      else
			tmp_length =
			  (unsigned int) (sizeof (unsigned int) * CHAR_BIT
					  * 0.25 /* binary -> hexadecimal */
					 )
			  + 1 /* turn floor into ceil */
			  + 2; /* account for leading sign or alternate form */
		      break;

		    case 'f': case 'F':
# ifdef 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 = xsum (tmp_length, precision);
		      break;

		    case 'e': case 'E': case 'g': case 'G':
		    case 'a': case 'A':
		      tmp_length =
			12; /* sign, decimal point, exponent etc. */
		      tmp_length = xsum (tmp_length, precision);
		      break;

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