strtod.c revision 77298
1/* Implementation of strtod for systems with atof. 2 Copyright (C) 1991, 1995 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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#include "ansidecl.h" 26#include "safe-ctype.h" 27 28extern double atof (); 29 30/* Disclaimer: this is currently just used by CHILL in GDB and therefore 31 has not been tested well. It may have been tested for nothing except 32 that it compiles. */ 33 34double 35strtod (str, ptr) 36 char *str; 37 char **ptr; 38{ 39 char *p; 40 41 if (ptr == (char **)0) 42 return atof (str); 43 44 p = str; 45 46 while (ISSPACE (*p)) 47 ++p; 48 49 if (*p == '+' || *p == '-') 50 ++p; 51 52 /* INF or INFINITY. */ 53 if ((p[0] == 'i' || p[0] == 'I') 54 && (p[1] == 'n' || p[1] == 'N') 55 && (p[2] == 'f' || p[2] == 'F')) 56 { 57 if ((p[3] == 'i' || p[3] == 'I') 58 && (p[4] == 'n' || p[4] == 'N') 59 && (p[5] == 'i' || p[5] == 'I') 60 && (p[6] == 't' || p[6] == 'T') 61 && (p[7] == 'y' || p[7] == 'Y')) 62 { 63 *ptr = p + 7; 64 return atof (str); 65 } 66 else 67 { 68 *ptr = p + 3; 69 return atof (str); 70 } 71 } 72 73 /* NAN or NAN(foo). */ 74 if ((p[0] == 'n' || p[0] == 'N') 75 && (p[1] == 'a' || p[1] == 'A') 76 && (p[2] == 'n' || p[2] == 'N')) 77 { 78 p += 3; 79 if (*p == '(') 80 { 81 ++p; 82 while (*p != '\0' && *p != ')') 83 ++p; 84 if (*p == ')') 85 ++p; 86 } 87 *ptr = p; 88 return atof (str); 89 } 90 91 /* digits, with 0 or 1 periods in it. */ 92 if (ISDIGIT (*p) || *p == '.') 93 { 94 int got_dot = 0; 95 while (ISDIGIT (*p) || (!got_dot && *p == '.')) 96 { 97 if (*p == '.') 98 got_dot = 1; 99 ++p; 100 } 101 102 /* Exponent. */ 103 if (*p == 'e' || *p == 'E') 104 { 105 int i; 106 i = 1; 107 if (p[i] == '+' || p[i] == '-') 108 ++i; 109 if (ISDIGIT (p[i])) 110 { 111 while (ISDIGIT (p[i])) 112 ++i; 113 *ptr = p + i; 114 return atof (str); 115 } 116 } 117 *ptr = p; 118 return atof (str); 119 } 120 /* Didn't find any digits. Doesn't look like a number. */ 121 *ptr = str; 122 return 0.0; 123} 124