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/* Implementation of strtod for systems with atof.

   Copyright (C) 1991, 1995, 2002, 2011 Free Software Foundation, Inc.

This file is part of the libiberty library.  This library 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 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 General Public License for more details.

You should have received a copy of the GNU General Public License

along with GNU CC; see the file COPYING.  If not, write to

the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.

As a special exception, if you link this library with files

compiled with a GNU compiler to produce an executable, this does not cause

the resulting executable to be covered by the GNU General Public License.

This exception does not however invalidate any other reasons why

the executable file might be covered by the GNU General Public License. */

/*

@deftypefn Supplemental double strtod (const char *@var{string}, @

  char **@var{endptr})

This ISO C function converts the initial portion of @var{string} to a

@code{double}.  If @var{endptr} is not @code{NULL}, a pointer to the

character after the last character used in the conversion is stored in

the location referenced by @var{endptr}.  If no conversion is

performed, zero is returned and the value of @var{string} is stored in

the location referenced by @var{endptr}.

@end deftypefn

*/

#include "ansidecl.h"

#include "safe-ctype.h"

extern double atof (const char *);

/* Disclaimer: this is currently just used by CHILL in GDB and therefore

   has not been tested well.  It may have been tested for nothing except

   that it compiles.  */

double

strtod (char *str, char **ptr)

{

  char *p;

  if (ptr == (char **)0)

    return atof (str);

  p = str;

  while (ISSPACE (*p))

    ++p;

  if (*p == '+' || *p == '-')

    ++p;

  /* INF or INFINITY.  */

  if ((p[0] == 'i' || p[0] == 'I')

      && (p[1] == 'n' || p[1] == 'N')

      && (p[2] == 'f' || p[2] == 'F'))

    {

      if ((p[3] == 'i' || p[3] == 'I')

          && (p[4] == 'n' || p[4] == 'N')

          && (p[5] == 'i' || p[5] == 'I')

          && (p[6] == 't' || p[6] == 'T')

          && (p[7] == 'y' || p[7] == 'Y'))

        {

          *ptr = p + 8;

          return atof (str);

        }

      else

        {

          *ptr = p + 3;

          return atof (str);

        }

    }

  /* NAN or NAN(foo).  */

  if ((p[0] == 'n' || p[0] == 'N')

      && (p[1] == 'a' || p[1] == 'A')

      && (p[2] == 'n' || p[2] == 'N'))

    {

      p += 3;

      if (*p == '(')

        {

          ++p;

          while (*p != '\0' && *p != ')')

            ++p;

          if (*p == ')')

            ++p;

        }

      *ptr = p;

      return atof (str);

    }

  /* digits, with 0 or 1 periods in it.  */

  if (ISDIGIT (*p) || *p == '.')

    {

      int got_dot = 0;

      while (ISDIGIT (*p) || (!got_dot && *p == '.'))

        {

          if (*p == '.')

            got_dot = 1;

          ++p;

        }

      /* Exponent.  */

      if (*p == 'e' || *p == 'E')

        {

          int i;

          i = 1;

          if (p[i] == '+' || p[i] == '-')

            ++i;

          if (ISDIGIT (p[i]))

            {

              while (ISDIGIT (p[i]))

                ++i;

              *ptr = p + i;

              return atof (str);

            }

        }

      *ptr = p;

      return atof (str);

    }

  /* Didn't find any digits.  Doesn't look like a number.  */

  *ptr = str;

  return 0.0;

}