1 /* Implementation of strtod for systems with atof. 2 Copyright (C) 1991, 1995, 2002, 2011 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}, @ 28 char **@var{endptr}) 29 30 This 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 32 character after the last character used in the conversion is stored in 33 the location referenced by @var{endptr}. If no conversion is 34 performed, zero is returned and the value of @var{string} is stored in 35 the location referenced by @var{endptr}. 36 37 @end deftypefn 38 39 */ 40 41 #include "ansidecl.h" 42 #include "safe-ctype.h" 43 44 extern 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 50 double 51 strtod (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