Changeset 391 for python/trunk/Python/mystrtoul.c
- Timestamp:
- Mar 19, 2014, 11:31:01 PM (11 years ago)
- Location:
- python/trunk
- Files:
-
- 2 edited
Legend:
- Unmodified
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python/trunk
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Property svn:mergeinfo
set to
/python/vendor/Python-2.7.6 merged eligible /python/vendor/current merged eligible
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Property svn:mergeinfo
set to
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python/trunk/Python/mystrtoul.c
r2 r391 19 19 */ 20 20 static unsigned long smallmax[] = { 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 21 0, /* bases 0 and 1 are invalid */ 22 0, 23 ULONG_MAX / 2, 24 ULONG_MAX / 3, 25 ULONG_MAX / 4, 26 ULONG_MAX / 5, 27 ULONG_MAX / 6, 28 ULONG_MAX / 7, 29 ULONG_MAX / 8, 30 ULONG_MAX / 9, 31 ULONG_MAX / 10, 32 ULONG_MAX / 11, 33 ULONG_MAX / 12, 34 ULONG_MAX / 13, 35 ULONG_MAX / 14, 36 ULONG_MAX / 15, 37 ULONG_MAX / 16, 38 ULONG_MAX / 17, 39 ULONG_MAX / 18, 40 ULONG_MAX / 19, 41 ULONG_MAX / 20, 42 ULONG_MAX / 21, 43 ULONG_MAX / 22, 44 ULONG_MAX / 23, 45 ULONG_MAX / 24, 46 ULONG_MAX / 25, 47 ULONG_MAX / 26, 48 ULONG_MAX / 27, 49 ULONG_MAX / 28, 50 ULONG_MAX / 29, 51 ULONG_MAX / 30, 52 ULONG_MAX / 31, 53 ULONG_MAX / 32, 54 ULONG_MAX / 33, 55 ULONG_MAX / 34, 56 ULONG_MAX / 35, 57 ULONG_MAX / 36, 58 58 }; 59 59 … … 64 64 #if SIZEOF_LONG == 4 65 65 static int digitlimit[] = { 66 67 68 69 66 0, 0, 32, 20, 16, 13, 12, 11, 10, 10, /* 0 - 9 */ 67 9, 9, 8, 8, 8, 8, 8, 7, 7, 7, /* 10 - 19 */ 68 7, 7, 7, 7, 6, 6, 6, 6, 6, 6, /* 20 - 29 */ 69 6, 6, 6, 6, 6, 6, 6}; /* 30 - 36 */ 70 70 #elif SIZEOF_LONG == 8 71 71 /* [int(math.floor(math.log(2**64, i))) for i in range(2, 37)] */ 72 72 static int digitlimit[] = { 73 74 75 76 73 0, 0, 64, 40, 32, 27, 24, 22, 21, 20, /* 0 - 9 */ 74 19, 18, 17, 17, 16, 16, 16, 15, 15, 15, /* 10 - 19 */ 75 14, 14, 14, 14, 13, 13, 13, 13, 13, 13, /* 20 - 29 */ 76 13, 12, 12, 12, 12, 12, 12}; /* 30 - 36 */ 77 77 #else 78 78 #error "Need table for SIZEOF_LONG" … … 80 80 81 81 /* 82 ** 83 ** 84 ** 85 ** 86 ** 87 ** 88 ** 89 ** 90 ** 91 ** 92 ** 82 ** strtoul 83 ** This is a general purpose routine for converting 84 ** an ascii string to an integer in an arbitrary base. 85 ** Leading white space is ignored. If 'base' is zero 86 ** it looks for a leading 0, 0b, 0B, 0o, 0O, 0x or 0X 87 ** to tell which base. If these are absent it defaults 88 ** to 10. Base must be 0 or between 2 and 36 (inclusive). 89 ** If 'ptr' is non-NULL it will contain a pointer to 90 ** the end of the scan. 91 ** Errors due to bad pointers will probably result in 92 ** exceptions - we don't check for them. 93 93 */ 94 94 unsigned long 95 95 PyOS_strtoul(register char *str, char **ptr, int base) 96 96 { 97 98 register int c;/* current input character */99 register int ovlimit;/* required digits to overflow */100 101 102 103 104 105 106 107 case 0:/* look for leading 0, 0b, 0o or 0x */108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 case 2:/* skip leading 0b or 0B */146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 case 8:/* skip leading 0o or 0O */161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 case 16:/* skip leading 0x or 0X */176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 97 register unsigned long result = 0; /* return value of the function */ 98 register int c; /* current input character */ 99 register int ovlimit; /* required digits to overflow */ 100 101 /* skip leading white space */ 102 while (*str && isspace(Py_CHARMASK(*str))) 103 ++str; 104 105 /* check for leading 0 or 0x for auto-base or base 16 */ 106 switch (base) { 107 case 0: /* look for leading 0, 0b, 0o or 0x */ 108 if (*str == '0') { 109 ++str; 110 if (*str == 'x' || *str == 'X') { 111 /* there must be at least one digit after 0x */ 112 if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 16) { 113 if (ptr) 114 *ptr = str; 115 return 0; 116 } 117 ++str; 118 base = 16; 119 } else if (*str == 'o' || *str == 'O') { 120 /* there must be at least one digit after 0o */ 121 if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) { 122 if (ptr) 123 *ptr = str; 124 return 0; 125 } 126 ++str; 127 base = 8; 128 } else if (*str == 'b' || *str == 'B') { 129 /* there must be at least one digit after 0b */ 130 if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) { 131 if (ptr) 132 *ptr = str; 133 return 0; 134 } 135 ++str; 136 base = 2; 137 } else { 138 base = 8; 139 } 140 } 141 else 142 base = 10; 143 break; 144 145 case 2: /* skip leading 0b or 0B */ 146 if (*str == '0') { 147 ++str; 148 if (*str == 'b' || *str == 'B') { 149 /* there must be at least one digit after 0b */ 150 if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 2) { 151 if (ptr) 152 *ptr = str; 153 return 0; 154 } 155 ++str; 156 } 157 } 158 break; 159 160 case 8: /* skip leading 0o or 0O */ 161 if (*str == '0') { 162 ++str; 163 if (*str == 'o' || *str == 'O') { 164 /* there must be at least one digit after 0o */ 165 if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 8) { 166 if (ptr) 167 *ptr = str; 168 return 0; 169 } 170 ++str; 171 } 172 } 173 break; 174 175 case 16: /* skip leading 0x or 0X */ 176 if (*str == '0') { 177 ++str; 178 if (*str == 'x' || *str == 'X') { 179 /* there must be at least one digit after 0x */ 180 if (_PyLong_DigitValue[Py_CHARMASK(str[1])] >= 16) { 181 if (ptr) 182 *ptr = str; 183 return 0; 184 } 185 ++str; 186 } 187 } 188 break; 189 } 190 191 /* catch silly bases */ 192 if (base < 2 || base > 36) { 193 if (ptr) 194 *ptr = str; 195 return 0; 196 } 197 198 /* skip leading zeroes */ 199 while (*str == '0') 200 ++str; 201 202 /* base is guaranteed to be in [2, 36] at this point */ 203 ovlimit = digitlimit[base]; 204 205 /* do the conversion until non-digit character encountered */ 206 while ((c = _PyLong_DigitValue[Py_CHARMASK(*str)]) < base) { 207 if (ovlimit > 0) /* no overflow check required */ 208 result = result * base + c; 209 else { /* requires overflow check */ 210 register unsigned long temp_result; 211 212 if (ovlimit < 0) /* guaranteed overflow */ 213 goto overflowed; 214 215 /* there could be an overflow */ 216 /* check overflow just from shifting */ 217 if (result > smallmax[base]) 218 goto overflowed; 219 220 result *= base; 221 222 /* check overflow from the digit's value */ 223 temp_result = result + c; 224 if (temp_result < result) 225 goto overflowed; 226 227 result = temp_result; 228 } 229 230 ++str; 231 --ovlimit; 232 } 233 234 /* set pointer to point to the last character scanned */ 235 if (ptr) 236 *ptr = str; 237 238 return result; 239 239 240 240 overflowed: 241 242 243 244 245 246 247 248 241 if (ptr) { 242 /* spool through remaining digit characters */ 243 while (_PyLong_DigitValue[Py_CHARMASK(*str)] < base) 244 ++str; 245 *ptr = str; 246 } 247 errno = ERANGE; 248 return (unsigned long)-1; 249 249 } 250 250 … … 252 252 * about PY_ABS_LONG_MIN in longobject.c. 253 253 */ 254 #define PY_ABS_LONG_MIN 254 #define PY_ABS_LONG_MIN (0-(unsigned long)LONG_MIN) 255 255 256 256 long 257 257 PyOS_strtol(char *str, char **ptr, int base) 258 258 { 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 259 long result; 260 unsigned long uresult; 261 char sign; 262 263 while (*str && isspace(Py_CHARMASK(*str))) 264 str++; 265 266 sign = *str; 267 if (sign == '+' || sign == '-') 268 str++; 269 270 uresult = PyOS_strtoul(str, ptr, base); 271 272 if (uresult <= (unsigned long)LONG_MAX) { 273 result = (long)uresult; 274 if (sign == '-') 275 result = -result; 276 } 277 else if (sign == '-' && uresult == PY_ABS_LONG_MIN) { 278 result = LONG_MIN; 279 } 280 else { 281 errno = ERANGE; 282 result = LONG_MAX; 283 } 284 return result; 285 285 }
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