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comparison libiberty/strtod.c @ 0:a06113de4d67

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author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
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children f6334be47118
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-1:000000000000 0:a06113de4d67
1 /* Implementation of strtod for systems with atof.
2 Copyright (C) 1991, 1995, 2002 Free Software Foundation, Inc.
3
4 This file is part of the libiberty library. This library is free
5 software; you can redistribute it and/or modify it under the
6 terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 2, or (at your option)
8 any later version.
9
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with GNU CC; see the file COPYING. If not, write to
17 the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
18
19 As a special exception, if you link this library with files
20 compiled with a GNU compiler to produce an executable, this does not cause
21 the resulting executable to be covered by the GNU General Public License.
22 This exception does not however invalidate any other reasons why
23 the 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
29 This 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
31 character after the last character used in the conversion is stored in
32 the location referenced by @var{endptr}. If no conversion is
33 performed, zero is returned and the value of @var{string} is stored in
34 the location referenced by @var{endptr}.
35
36 @end deftypefn
37
38 */
39
40 #include "ansidecl.h"
41 #include "safe-ctype.h"
42
43 extern 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
49 double
50 strtod (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 }