libc/newlib/libc/stdio/nano-vfprintf_float.c

/*
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <newlib.h>

#include <_ansi.h>
#include <reent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <stdint.h>
#include <wchar.h>
#include <sys/lock.h>
#include <stdarg.h>
#include "local.h"
#include "../stdlib/local.h"
#include "fvwrite.h"
#include "vfieeefp.h"
#include "nano-vfprintf_local.h"

char *__cvt (struct _reent *data, _PRINTF_FLOAT_TYPE value, int ndigits,
	     int flags, char *sign, int *decpt, int ch, int *length,
	     char *buf);

int __exponent (char *p0, int exp, int fmtch);

#ifdef FLOATING_POINT

/* Using reentrant DATA, convert finite VALUE into a string of digits
   with no decimal point, using NDIGITS precision and FLAGS as guides
   to whether trailing zeros must be included.  Set *SIGN to nonzero
   if VALUE was negative.  Set *DECPT to the exponent plus one.  Set
   *LENGTH to the length of the returned string.  CH must be one of
   [aAeEfFgG]; if it is [aA], then the return string lives in BUF,
   otherwise the return value shares the mprec reentrant storage.  */
char *
__cvt (struct _reent *data, _PRINTF_FLOAT_TYPE value, int ndigits, int flags,
       char *sign, int *decpt, int ch, int *length, char *buf)
{
  int mode, dsgn;
  char *digits, *bp, *rve;
  union double_union tmp;

  tmp.d = value;
  /* This will check for "< 0" and "-0.0".  */
  if (word0 (tmp) & Sign_bit)
    {
      value = -value;
      *sign = '-';
    }
  else
    *sign = '\000';

  if (ch == 'f' || ch == 'F')
    {
      /* Ndigits after the decimal point.  */
      mode = 3;
    }
  else
    {
      /* To obtain ndigits after the decimal point for the 'e'
	 and 'E' formats, round to ndigits + 1 significant figures.  */
      if (ch == 'e' || ch == 'E')
	{
	  ndigits++;
	}
      /* Ndigits significant digits.  */
      mode = 2;
    }

  digits = _DTOA_R (data, value, mode, ndigits, decpt, &dsgn, &rve);

  /* Print trailing zeros.  */
  if ((ch != 'g' && ch != 'G') || flags & ALT)
    {
      bp = digits + ndigits;
      if (ch == 'f' || ch == 'F')
	{
	  if (*digits == '0' && value)
	    *decpt = -ndigits + 1;
	  bp += *decpt;
	}
      /* Kludge for __dtoa irregularity.  */
      if (value == 0)
	rve = bp;
      while (rve < bp)
	*rve++ = '0';
    }
  *length = rve - digits;
  return (digits);
}

/* This function is copied from exponent in vfprintf.c with support for
   C99 formats removed.  We don't use the original function in order to
   decouple nano implementation of formatted IO from the Newlib one.  */
int
__exponent (char *p0, int exp, int fmtch)
{
  register char *p, *t;
  char expbuf[MAXEXPLEN];
#define isa 0

  p = p0;
  *p++ = isa ? 'p' - 'a' + fmtch : fmtch;
  if (exp < 0)
    {
      exp = -exp;
      *p++ = '-';
    }
  else
    *p++ = '+';
  t = expbuf + MAXEXPLEN;
  if (exp > 9)
    {
      do
	{
	  *--t = to_char (exp % 10);
	}
      while ((exp /= 10) > 9);
      *--t = to_char (exp);
      for (; t < expbuf + MAXEXPLEN; *p++ = *t++);
    }
  else
    {
      if (!isa)
	*p++ = '0';
      *p++ = to_char (exp);
    }
  return (p - p0);
}

/* Decode and print floating point number specified by "eEfgG".  */
int
_printf_float (struct _reent *data,
	       struct _prt_data_t *pdata,
	       FILE * fp,
	       int (*pfunc) (struct _reent *, FILE *, const char *,
			     size_t len), va_list * ap)
{
#define _fpvalue (pdata->_double_)

  char *decimal_point = _localeconv_r (data)->decimal_point;
  size_t decp_len = strlen (decimal_point);
  /* Temporary negative sign for floats.  */
  char softsign;
  /* Integer value of exponent.  */
  int expt;
  /* Character count for expstr.  */
  int expsize = 0;
  /* Actual number of digits returned by cvt.  */
  int ndig = 0;
  char *cp;
  int n;
  /* Field size expanded by dprec(not for _printf_float).  */
  int realsz;
  char code = pdata->code;

  if (pdata->flags & LONGDBL)
    {
      _fpvalue = (double) GET_ARG (N, *ap, _LONG_DOUBLE);
    }
  else
    {
      _fpvalue = GET_ARG (N, *ap, double);
    }

  /* Do this before tricky precision changes.

     If the output is infinite or NaN, leading
     zeros are not permitted.  Otherwise, scanf
     could not read what printf wrote.  */
  if (isinf (_fpvalue))
    {
      if (_fpvalue < 0)
	pdata->l_buf[0] = '-';
      if (code <= 'G')		/* 'A', 'E', 'F', or 'G'.  */
	cp = "INF";
      else
	cp = "inf";
      pdata->size = 3;
      pdata->flags &= ~ZEROPAD;
      goto print_float;
    }
  if (isnan (_fpvalue))
    {
      if (_fpvalue < 0)
	pdata->l_buf[0] = '-';
      if (code <= 'G')		/* 'A', 'E', 'F', or 'G'.  */
	cp = "NAN";
      else
	cp = "nan";
      pdata->size = 3;
      pdata->flags &= ~ZEROPAD;
      goto print_float;
    }

  if (pdata->prec == -1)
    {
      pdata->prec = DEFPREC;
    }
  else if ((code == 'g' || code == 'G') && pdata->prec == 0)
    {
      pdata->prec = 1;
    }

  pdata->flags |= FPT;

  cp = __cvt (data, _fpvalue, pdata->prec, pdata->flags, &softsign,
	      &expt, code, &ndig, cp);

  if (code == 'g' || code == 'G')
    {
      if (expt <= -4 || expt > pdata->prec)
	/* 'e' or 'E'.  */
	code -= 2;
      else
	code = 'g';
    }
  if (code <= 'e')
    {
      /* 'a', 'A', 'e', or 'E' fmt.  */
      --expt;
      expsize = __exponent (pdata->expstr, expt, code);
      pdata->size = expsize + ndig;
      if (ndig > 1 || pdata->flags & ALT)
	++pdata->size;
    }
  else
    {
      if (code == 'f')
	{
	  /* 'f' fmt.  */
	  if (expt > 0)
	    {
	      pdata->size = expt;
	      if (pdata->prec || pdata->flags & ALT)
		pdata->size += pdata->prec + 1;
	    }
	  else
	    /* "0.X".  */
	    pdata->size = (pdata->prec || pdata->flags & ALT)
	      ? pdata->prec + 2 : 1;
	}
      else if (expt >= ndig)
	{
	  /* Fixed g fmt.  */
	  pdata->size = expt;
	  if (pdata->flags & ALT)
	    ++pdata->size;
	}
      else
	pdata->size = ndig + (expt > 0 ? 1 : 2 - expt);
      pdata->lead = expt;
    }

  if (softsign)
    pdata->l_buf[0] = '-';
print_float:
  if (_printf_common (data, pdata, &realsz, fp, pfunc) == -1)
    goto error;

  if ((pdata->flags & FPT) == 0)
    {
      PRINT (cp, pdata->size);
    }
  else
    {
      /* Glue together f_p fragments.  */
      if (code >= 'f')
	{
	  /* 'f' or 'g'.  */
	  if (_fpvalue == 0)
	    {
	      /* Kludge for __dtoa irregularity.  */
	      PRINT ("0", 1);
	      if (expt < ndig || pdata->flags & ALT)
		{
		  PRINT (decimal_point, decp_len);
		  PAD (ndig - 1, pdata->zero);
		}
	    }
	  else if (expt <= 0)
	    {
	      PRINT ("0", 1);
	      if (expt || ndig || pdata->flags & ALT)
		{
		  PRINT (decimal_point, decp_len);
		  PAD (-expt, pdata->zero);
		  PRINT (cp, ndig);
		}
	    }
	  else
	    {
	      char *convbuf = cp;
	      PRINTANDPAD (cp, convbuf + ndig, pdata->lead, pdata->zero);
	      cp += pdata->lead;
	      if (expt < ndig || pdata->flags & ALT)
		PRINT (decimal_point, decp_len);
	      PRINTANDPAD (cp, convbuf + ndig, ndig - expt, pdata->zero);
	    }
	}
      else
	{
	  /* 'a', 'A', 'e', or 'E'.  */
	  if (ndig > 1 || pdata->flags & ALT)
	    {
	      PRINT (cp, 1);
	      cp++;
	      PRINT (decimal_point, decp_len);
	      if (_fpvalue)
		{
		  PRINT (cp, ndig - 1);
		}
	      /* "0.[0..]".  */
	      else
		/* __dtoa irregularity.  */
		PAD (ndig - 1, pdata->zero);
	    }
	  else			/* "XeYYY".  */
	    PRINT (cp, 1);
	  PRINT (pdata->expstr, expsize);
	}
    }

  /* Left-adjusting padding (always blank).  */
  if (pdata->flags & LADJUST)
    PAD (pdata->width - realsz, pdata->blank);

  return (pdata->width > realsz ? pdata->width : realsz);
error:
  return -1;

#undef _fpvalue
}

#endif