1/* Implementation of strtod for systems with atof.
2   Copyright (C) 1991, 1995, 2002, 2011 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}, @
28  char **@var{endptr})
29
30This ISO C function converts the initial portion of @var{string} to a
31@code{double}.  If @var{endptr} is not @code{NULL}, a pointer to the
32character after the last character used in the conversion is stored in
33the location referenced by @var{endptr}.  If no conversion is
34performed, zero is returned and the value of @var{string} is stored in
35the location referenced by @var{endptr}.
36
37@end deftypefn
38
39*/
40
41#include "ansidecl.h"
42#include "safe-ctype.h"
43
44extern double atof (const char *);
45
46/* Disclaimer: this is currently just used by CHILL in GDB and therefore
47   has not been tested well.  It may have been tested for nothing except
48   that it compiles.  */
49
50double
51strtod (char *str, char **ptr)
52{
53  char *p;
54
55  if (ptr == (char **)0)
56    return atof (str);
57
58  p = str;
59
60  while (ISSPACE (*p))
61    ++p;
62
63  if (*p == '+' || *p == '-')
64    ++p;
65
66  /* INF or INFINITY.  */
67  if ((p[0] == 'i' || p[0] == 'I')
68      && (p[1] == 'n' || p[1] == 'N')
69      && (p[2] == 'f' || p[2] == 'F'))
70    {
71      if ((p[3] == 'i' || p[3] == 'I')
72	  && (p[4] == 'n' || p[4] == 'N')
73	  && (p[5] == 'i' || p[5] == 'I')
74	  && (p[6] == 't' || p[6] == 'T')
75	  && (p[7] == 'y' || p[7] == 'Y'))
76	{
77	  *ptr = p + 8;
78	  return atof (str);
79	}
80      else
81	{
82	  *ptr = p + 3;
83	  return atof (str);
84	}
85    }
86
87  /* NAN or NAN(foo).  */
88  if ((p[0] == 'n' || p[0] == 'N')
89      && (p[1] == 'a' || p[1] == 'A')
90      && (p[2] == 'n' || p[2] == 'N'))
91    {
92      p += 3;
93      if (*p == '(')
94	{
95	  ++p;
96	  while (*p != '\0' && *p != ')')
97	    ++p;
98	  if (*p == ')')
99	    ++p;
100	}
101      *ptr = p;
102      return atof (str);
103    }
104
105  /* digits, with 0 or 1 periods in it.  */
106  if (ISDIGIT (*p) || *p == '.')
107    {
108      int got_dot = 0;
109      while (ISDIGIT (*p) || (!got_dot && *p == '.'))
110	{
111	  if (*p == '.')
112	    got_dot = 1;
113	  ++p;
114	}
115
116      /* Exponent.  */
117      if (*p == 'e' || *p == 'E')
118	{
119	  int i;
120	  i = 1;
121	  if (p[i] == '+' || p[i] == '-')
122	    ++i;
123	  if (ISDIGIT (p[i]))
124	    {
125	      while (ISDIGIT (p[i]))
126		++i;
127	      *ptr = p + i;
128	      return atof (str);
129	    }
130	}
131      *ptr = p;
132      return atof (str);
133    }
134  /* Didn't find any digits.  Doesn't look like a number.  */
135  *ptr = str;
136  return 0.0;
137}
138