1/* Implementation of strtod for systems with atof.
2   Copyright (C) 1991, 1995, 2002 Free Software Foundation, Inc.
3
4This file is part of the libiberty library.  This library is free
5software; you can redistribute it and/or modify it under the
6terms of the GNU General Public License as published by the
7Free Software Foundation; either version 2, or (at your option)
8any later version.
9
10This library is distributed in the hope that it will be useful,
11but WITHOUT ANY WARRANTY; without even the implied warranty of
12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with GNU CC; see the file COPYING.  If not, write to
17the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
18
19As a special exception, if you link this library with files
20compiled with a GNU compiler to produce an executable, this does not cause
21the resulting executable to be covered by the GNU General Public License.
22This exception does not however invalidate any other reasons why
23the executable file might be covered by the GNU General Public License. */
24
25/*
26
27@deftypefn Supplemental double strtod (const char *@var{string}, char **@var{endptr})
28
29This ISO C function converts the initial portion of @var{string} to a
30@code{double}.  If @var{endptr} is not @code{NULL}, a pointer to the
31character after the last character used in the conversion is stored in
32the location referenced by @var{endptr}.  If no conversion is
33performed, zero is returned and the value of @var{string} is stored in
34the location referenced by @var{endptr}.
35
36@end deftypefn
37
38*/
39
40#include "ansidecl.h"
41#include "safe-ctype.h"
42
43extern double atof (const char *);
44
45/* Disclaimer: this is currently just used by CHILL in GDB and therefore
46   has not been tested well.  It may have been tested for nothing except
47   that it compiles.  */
48
49double
50strtod (char *str, char **ptr)
51{
52  char *p;
53
54  if (ptr == (char **)0)
55    return atof (str);
56
57  p = str;
58
59  while (ISSPACE (*p))
60    ++p;
61
62  if (*p == '+' || *p == '-')
63    ++p;
64
65  /* INF or INFINITY.  */
66  if ((p[0] == 'i' || p[0] == 'I')
67      && (p[1] == 'n' || p[1] == 'N')
68      && (p[2] == 'f' || p[2] == 'F'))
69    {
70      if ((p[3] == 'i' || p[3] == 'I')
71	  && (p[4] == 'n' || p[4] == 'N')
72	  && (p[5] == 'i' || p[5] == 'I')
73	  && (p[6] == 't' || p[6] == 'T')
74	  && (p[7] == 'y' || p[7] == 'Y'))
75	{
76	  *ptr = p + 8;
77	  return atof (str);
78	}
79      else
80	{
81	  *ptr = p + 3;
82	  return atof (str);
83	}
84    }
85
86  /* NAN or NAN(foo).  */
87  if ((p[0] == 'n' || p[0] == 'N')
88      && (p[1] == 'a' || p[1] == 'A')
89      && (p[2] == 'n' || p[2] == 'N'))
90    {
91      p += 3;
92      if (*p == '(')
93	{
94	  ++p;
95	  while (*p != '\0' && *p != ')')
96	    ++p;
97	  if (*p == ')')
98	    ++p;
99	}
100      *ptr = p;
101      return atof (str);
102    }
103
104  /* digits, with 0 or 1 periods in it.  */
105  if (ISDIGIT (*p) || *p == '.')
106    {
107      int got_dot = 0;
108      while (ISDIGIT (*p) || (!got_dot && *p == '.'))
109	{
110	  if (*p == '.')
111	    got_dot = 1;
112	  ++p;
113	}
114
115      /* Exponent.  */
116      if (*p == 'e' || *p == 'E')
117	{
118	  int i;
119	  i = 1;
120	  if (p[i] == '+' || p[i] == '-')
121	    ++i;
122	  if (ISDIGIT (p[i]))
123	    {
124	      while (ISDIGIT (p[i]))
125		++i;
126	      *ptr = p + i;
127	      return atof (str);
128	    }
129	}
130      *ptr = p;
131      return atof (str);
132    }
133  /* Didn't find any digits.  Doesn't look like a number.  */
134  *ptr = str;
135  return 0.0;
136}
137