diff options
Diffstat (limited to 'Python/pystrtod.c')
| -rw-r--r-- | Python/pystrtod.c | 616 |
1 files changed, 429 insertions, 187 deletions
diff --git a/Python/pystrtod.c b/Python/pystrtod.c index 6c19b45fd2..9004cf4641 100644 --- a/Python/pystrtod.c +++ b/Python/pystrtod.c @@ -5,9 +5,8 @@ /* ascii character tests (as opposed to locale tests) */ #define ISSPACE(c) ((c) == ' ' || (c) == '\f' || (c) == '\n' || \ - (c) == '\r' || (c) == '\t' || (c) == '\v') + (c) == '\r' || (c) == '\t' || (c) == '\v') #define ISDIGIT(c) ((c) >= '0' && (c) <= '9') -#define ISXDIGIT(c) (ISDIGIT(c) || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F')) /** @@ -15,7 +14,7 @@ * @nptr: the string to convert to a numeric value. * @endptr: if non-%NULL, it returns the character after * the last character used in the conversion. - * + * * Converts a string to a #gdouble value. * This function behaves like the standard strtod() function * does in the C locale. It does this without actually @@ -32,7 +31,7 @@ * stored in %errno. If the correct value would cause underflow, * zero is returned and %ERANGE is stored in %errno. * If memory allocation fails, %ENOMEM is stored in %errno. - * + * * This function resets %errno before calling strtod() so that * you can reliably detect overflow and underflow. * @@ -41,208 +40,451 @@ double PyOS_ascii_strtod(const char *nptr, char **endptr) { - char *fail_pos; - double val = -1.0; - struct lconv *locale_data; - const char *decimal_point; - size_t decimal_point_len; - const char *p, *decimal_point_pos; - const char *end = NULL; /* Silence gcc */ - - assert(nptr != NULL); - - fail_pos = NULL; - - locale_data = localeconv(); - decimal_point = locale_data->decimal_point; - decimal_point_len = strlen(decimal_point); - - assert(decimal_point_len != 0); - - decimal_point_pos = NULL; - if (decimal_point[0] != '.' || - decimal_point[1] != 0) - { - p = nptr; - /* Skip leading space */ - while (ISSPACE(*p)) - p++; - - /* Skip leading optional sign */ - if (*p == '+' || *p == '-') - p++; - - while (ISDIGIT(*p)) - p++; - - if (*p == '.') - { - decimal_point_pos = p++; - - while (ISDIGIT(*p)) - p++; - - if (*p == 'e' || *p == 'E') - p++; - if (*p == '+' || *p == '-') - p++; - while (ISDIGIT(*p)) - p++; - end = p; - } - else if (strncmp(p, decimal_point, decimal_point_len) == 0) - { - /* Python bug #1417699 */ - *endptr = (char*)nptr; - errno = EINVAL; - return val; - } - /* For the other cases, we need not convert the decimal point */ - } - - /* Set errno to zero, so that we can distinguish zero results - and underflows */ - errno = 0; - - if (decimal_point_pos) - { - char *copy, *c; - - /* We need to convert the '.' to the locale specific decimal point */ - copy = (char *)PyMem_MALLOC(end - nptr + 1 + decimal_point_len); - if (copy == NULL) { - if (endptr) - *endptr = (char *)nptr; - errno = ENOMEM; - return val; - } - - c = copy; - memcpy(c, nptr, decimal_point_pos - nptr); - c += decimal_point_pos - nptr; - memcpy(c, decimal_point, decimal_point_len); - c += decimal_point_len; - memcpy(c, decimal_point_pos + 1, end - (decimal_point_pos + 1)); - c += end - (decimal_point_pos + 1); - *c = 0; - - val = strtod(copy, &fail_pos); - - if (fail_pos) - { - if (fail_pos > decimal_point_pos) - fail_pos = (char *)nptr + (fail_pos - copy) - (decimal_point_len - 1); - else - fail_pos = (char *)nptr + (fail_pos - copy); - } - - PyMem_FREE(copy); - - } - else { - unsigned i = 0; - if (nptr[i] == '-') - i++; - if (nptr[i] == '0' && (nptr[i+1] == 'x' || nptr[i+1] == 'X')) - fail_pos = (char*)nptr; - else - val = strtod(nptr, &fail_pos); - } - - if (endptr) - *endptr = fail_pos; - - return val; + char *fail_pos; + double val = -1.0; + struct lconv *locale_data; + const char *decimal_point; + size_t decimal_point_len; + const char *p, *decimal_point_pos; + const char *end = NULL; /* Silence gcc */ + const char *digits_pos = NULL; + int negate = 0; + + assert(nptr != NULL); + + fail_pos = NULL; + + locale_data = localeconv(); + decimal_point = locale_data->decimal_point; + decimal_point_len = strlen(decimal_point); + + assert(decimal_point_len != 0); + + decimal_point_pos = NULL; + + /* We process any leading whitespace and the optional sign manually, + then pass the remainder to the system strtod. This ensures that + the result of an underflow has the correct sign. (bug #1725) */ + + p = nptr; + /* Skip leading space */ + while (ISSPACE(*p)) + p++; + + /* Process leading sign, if present */ + if (*p == '-') { + negate = 1; + p++; + } else if (*p == '+') { + p++; + } + + /* What's left should begin with a digit, a decimal point, or one of + the letters i, I, n, N. It should not begin with 0x or 0X */ + if ((!ISDIGIT(*p) && + *p != '.' && *p != 'i' && *p != 'I' && *p != 'n' && *p != 'N') + || + (*p == '0' && (p[1] == 'x' || p[1] == 'X'))) + { + if (endptr) + *endptr = (char*)nptr; + errno = EINVAL; + return val; + } + digits_pos = p; + + if (decimal_point[0] != '.' || + decimal_point[1] != 0) + { + while (ISDIGIT(*p)) + p++; + + if (*p == '.') + { + decimal_point_pos = p++; + + while (ISDIGIT(*p)) + p++; + + if (*p == 'e' || *p == 'E') + p++; + if (*p == '+' || *p == '-') + p++; + while (ISDIGIT(*p)) + p++; + end = p; + } + else if (strncmp(p, decimal_point, decimal_point_len) == 0) + { + /* Python bug #1417699 */ + if (endptr) + *endptr = (char*)nptr; + errno = EINVAL; + return val; + } + /* For the other cases, we need not convert the decimal + point */ + } + + /* Set errno to zero, so that we can distinguish zero results + and underflows */ + errno = 0; + + if (decimal_point_pos) + { + char *copy, *c; + + /* We need to convert the '.' to the locale specific decimal + point */ + copy = (char *)PyMem_MALLOC(end - digits_pos + + 1 + decimal_point_len); + if (copy == NULL) { + if (endptr) + *endptr = (char *)nptr; + errno = ENOMEM; + return val; + } + + c = copy; + memcpy(c, digits_pos, decimal_point_pos - digits_pos); + c += decimal_point_pos - digits_pos; + memcpy(c, decimal_point, decimal_point_len); + c += decimal_point_len; + memcpy(c, decimal_point_pos + 1, + end - (decimal_point_pos + 1)); + c += end - (decimal_point_pos + 1); + *c = 0; + + val = strtod(copy, &fail_pos); + + if (fail_pos) + { + if (fail_pos > decimal_point_pos) + fail_pos = (char *)digits_pos + + (fail_pos - copy) - + (decimal_point_len - 1); + else + fail_pos = (char *)digits_pos + + (fail_pos - copy); + } + + PyMem_FREE(copy); + + } + else { + val = strtod(digits_pos, &fail_pos); + } + + if (fail_pos == digits_pos) + fail_pos = (char *)nptr; + + if (negate && fail_pos != nptr) + val = -val; + + if (endptr) + *endptr = fail_pos; + + return val; +} + +/* Given a string that may have a decimal point in the current + locale, change it back to a dot. Since the string cannot get + longer, no need for a maximum buffer size parameter. */ +Py_LOCAL_INLINE(void) +change_decimal_from_locale_to_dot(char* buffer) +{ + struct lconv *locale_data = localeconv(); + const char *decimal_point = locale_data->decimal_point; + + if (decimal_point[0] != '.' || decimal_point[1] != 0) { + size_t decimal_point_len = strlen(decimal_point); + + if (*buffer == '+' || *buffer == '-') + buffer++; + while (isdigit(Py_CHARMASK(*buffer))) + buffer++; + if (strncmp(buffer, decimal_point, decimal_point_len) == 0) { + *buffer = '.'; + buffer++; + if (decimal_point_len > 1) { + /* buffer needs to get smaller */ + size_t rest_len = strlen(buffer + + (decimal_point_len - 1)); + memmove(buffer, + buffer + (decimal_point_len - 1), + rest_len); + buffer[rest_len] = 0; + } + } + } } +/* From the C99 standard, section 7.19.6: +The exponent always contains at least two digits, and only as many more digits +as necessary to represent the exponent. +*/ +#define MIN_EXPONENT_DIGITS 2 + +/* Ensure that any exponent, if present, is at least MIN_EXPONENT_DIGITS + in length. */ +Py_LOCAL_INLINE(void) +ensure_minimum_exponent_length(char* buffer, size_t buf_size) +{ + char *p = strpbrk(buffer, "eE"); + if (p && (*(p + 1) == '-' || *(p + 1) == '+')) { + char *start = p + 2; + int exponent_digit_cnt = 0; + int leading_zero_cnt = 0; + int in_leading_zeros = 1; + int significant_digit_cnt; + + /* Skip over the exponent and the sign. */ + p += 2; + + /* Find the end of the exponent, keeping track of leading + zeros. */ + while (*p && isdigit(Py_CHARMASK(*p))) { + if (in_leading_zeros && *p == '0') + ++leading_zero_cnt; + if (*p != '0') + in_leading_zeros = 0; + ++p; + ++exponent_digit_cnt; + } + + significant_digit_cnt = exponent_digit_cnt - leading_zero_cnt; + if (exponent_digit_cnt == MIN_EXPONENT_DIGITS) { + /* If there are 2 exactly digits, we're done, + regardless of what they contain */ + } + else if (exponent_digit_cnt > MIN_EXPONENT_DIGITS) { + int extra_zeros_cnt; + + /* There are more than 2 digits in the exponent. See + if we can delete some of the leading zeros */ + if (significant_digit_cnt < MIN_EXPONENT_DIGITS) + significant_digit_cnt = MIN_EXPONENT_DIGITS; + extra_zeros_cnt = exponent_digit_cnt - + significant_digit_cnt; + + /* Delete extra_zeros_cnt worth of characters from the + front of the exponent */ + assert(extra_zeros_cnt >= 0); + + /* Add one to significant_digit_cnt to copy the + trailing 0 byte, thus setting the length */ + memmove(start, + start + extra_zeros_cnt, + significant_digit_cnt + 1); + } + else { + /* If there are fewer than 2 digits, add zeros + until there are 2, if there's enough room */ + int zeros = MIN_EXPONENT_DIGITS - exponent_digit_cnt; + if (start + zeros + exponent_digit_cnt + 1 + < buffer + buf_size) { + memmove(start + zeros, start, + exponent_digit_cnt + 1); + memset(start, '0', zeros); + } + } + } +} + +/* Ensure that buffer has a decimal point in it. The decimal point + will not be in the current locale, it will always be '.' */ +Py_LOCAL_INLINE(void) +ensure_decimal_point(char* buffer, size_t buf_size) +{ + int insert_count = 0; + char* chars_to_insert; + + /* search for the first non-digit character */ + char *p = buffer; + if (*p == '-' || *p == '+') + /* Skip leading sign, if present. I think this could only + ever be '-', but it can't hurt to check for both. */ + ++p; + while (*p && isdigit(Py_CHARMASK(*p))) + ++p; + + if (*p == '.') { + if (isdigit(Py_CHARMASK(*(p+1)))) { + /* Nothing to do, we already have a decimal + point and a digit after it */ + } + else { + /* We have a decimal point, but no following + digit. Insert a zero after the decimal. */ + ++p; + chars_to_insert = "0"; + insert_count = 1; + } + } + else { + chars_to_insert = ".0"; + insert_count = 2; + } + if (insert_count) { + size_t buf_len = strlen(buffer); + if (buf_len + insert_count + 1 >= buf_size) { + /* If there is not enough room in the buffer + for the additional text, just skip it. It's + not worth generating an error over. */ + } + else { + memmove(p + insert_count, p, + buffer + strlen(buffer) - p + 1); + memcpy(p, chars_to_insert, insert_count); + } + } +} + +/* Add the locale specific grouping characters to buffer. Note + that any decimal point (if it's present) in buffer is already + locale-specific. Return 0 on error, else 1. */ +Py_LOCAL_INLINE(int) +add_thousands_grouping(char* buffer, size_t buf_size) +{ + Py_ssize_t len = strlen(buffer); + struct lconv *locale_data = localeconv(); + const char *decimal_point = locale_data->decimal_point; + + /* Find the decimal point, if any. We're only concerned + about the characters to the left of the decimal when + adding grouping. */ + char *p = strstr(buffer, decimal_point); + if (!p) { + /* No decimal, use the entire string. */ + + /* If any exponent, adjust p. */ + p = strpbrk(buffer, "eE"); + if (!p) + /* No exponent and no decimal. Use the entire + string. */ + p = buffer + len; + } + /* At this point, p points just past the right-most character we + want to format. We need to add the grouping string for the + characters between buffer and p. */ + return _PyString_InsertThousandsGrouping(buffer, len, p-buffer, + buf_size, NULL, 1); +} + +/* see FORMATBUFLEN in unicodeobject.c */ +#define FLOAT_FORMATBUFLEN 120 + /** * PyOS_ascii_formatd: * @buffer: A buffer to place the resulting string in - * @buf_len: The length of the buffer. + * @buf_size: The length of the buffer. * @format: The printf()-style format to use for the - * code to use for converting. + * code to use for converting. * @d: The #gdouble to convert * * Converts a #gdouble to a string, using the '.' as * decimal point. To format the number you pass in * a printf()-style format string. Allowed conversion - * specifiers are 'e', 'E', 'f', 'F', 'g' and 'G'. - * + * specifiers are 'e', 'E', 'f', 'F', 'g', 'G', and 'n'. + * + * 'n' is the same as 'g', except it uses the current locale. + * 'Z' is the same as 'g', except it always has a decimal and + * at least one digit after the decimal. + * * Return value: The pointer to the buffer with the converted string. **/ char * -PyOS_ascii_formatd(char *buffer, - size_t buf_len, - const char *format, - double d) +PyOS_ascii_formatd(char *buffer, + size_t buf_size, + const char *format, + double d) { - struct lconv *locale_data; - const char *decimal_point; - size_t decimal_point_len, rest_len; - char *p; - char format_char; - -/* g_return_val_if_fail (buffer != NULL, NULL); */ -/* g_return_val_if_fail (format[0] == '%', NULL); */ -/* g_return_val_if_fail (strpbrk (format + 1, "'l%") == NULL, NULL); */ - - format_char = format[strlen(format) - 1]; - -/* g_return_val_if_fail (format_char == 'e' || format_char == 'E' || */ -/* format_char == 'f' || format_char == 'F' || */ -/* format_char == 'g' || format_char == 'G', */ -/* NULL); */ - - if (format[0] != '%') - return NULL; - - if (strpbrk(format + 1, "'l%")) - return NULL; - - if (!(format_char == 'e' || format_char == 'E' || - format_char == 'f' || format_char == 'F' || - format_char == 'g' || format_char == 'G')) - return NULL; - - - PyOS_snprintf(buffer, buf_len, format, d); - - locale_data = localeconv(); - decimal_point = locale_data->decimal_point; - decimal_point_len = strlen(decimal_point); - - assert(decimal_point_len != 0); - - if (decimal_point[0] != '.' || - decimal_point[1] != 0) - { - p = buffer; - - if (*p == '+' || *p == '-') - p++; - - while (isdigit((unsigned char)*p)) - p++; - - if (strncmp(p, decimal_point, decimal_point_len) == 0) - { - *p = '.'; - p++; - if (decimal_point_len > 1) { - rest_len = strlen(p + (decimal_point_len - 1)); - memmove(p, p + (decimal_point_len - 1), - rest_len); - p[rest_len] = 0; - } - } - } - - return buffer; + char format_char; + size_t format_len = strlen(format); + + /* For type 'n', we need to make a copy of the format string, because + we're going to modify 'n' -> 'g', and format is const char*, so we + can't modify it directly. FLOAT_FORMATBUFLEN should be longer than + we ever need this to be. There's an upcoming check to ensure it's + big enough. */ + /* Issue 2264: code 'Z' requires copying the format. 'Z' is 'g', but + also with at least one character past the decimal. */ + char tmp_format[FLOAT_FORMATBUFLEN]; + + /* The last character in the format string must be the format char */ + format_char = format[format_len - 1]; + + if (format[0] != '%') + return NULL; + + /* I'm not sure why this test is here. It's ensuring that the format + string after the first character doesn't have a single quote, a + lowercase l, or a percent. This is the reverse of the commented-out + test about 10 lines ago. */ + if (strpbrk(format + 1, "'l%")) + return NULL; + + /* Also curious about this function is that it accepts format strings + like "%xg", which are invalid for floats. In general, the + interface to this function is not very good, but changing it is + difficult because it's a public API. */ + + if (!(format_char == 'e' || format_char == 'E' || + format_char == 'f' || format_char == 'F' || + format_char == 'g' || format_char == 'G' || + format_char == 'n' || format_char == 'Z')) + return NULL; + + /* Map 'n' or 'Z' format_char to 'g', by copying the format string and + replacing the final char with a 'g' */ + if (format_char == 'n' || format_char == 'Z') { + if (format_len + 1 >= sizeof(tmp_format)) { + /* The format won't fit in our copy. Error out. In + practice, this will never happen and will be + detected by returning NULL */ + return NULL; + } + strcpy(tmp_format, format); + tmp_format[format_len - 1] = 'g'; + format = tmp_format; + } + + + /* Have PyOS_snprintf do the hard work */ + PyOS_snprintf(buffer, buf_size, format, d); + + /* Do various fixups on the return string */ + + /* Get the current locale, and find the decimal point string. + Convert that string back to a dot. Do not do this if using the + 'n' (number) format code, since we want to keep the localized + decimal point in that case. */ + if (format_char != 'n') + change_decimal_from_locale_to_dot(buffer); + + /* If an exponent exists, ensure that the exponent is at least + MIN_EXPONENT_DIGITS digits, providing the buffer is large enough + for the extra zeros. Also, if there are more than + MIN_EXPONENT_DIGITS, remove as many zeros as possible until we get + back to MIN_EXPONENT_DIGITS */ + ensure_minimum_exponent_length(buffer, buf_size); + + /* If format_char is 'Z', make sure we have at least one character + after the decimal point (and make sure we have a decimal point). */ + if (format_char == 'Z') + ensure_decimal_point(buffer, buf_size); + + /* If format_char is 'n', add the thousands grouping. */ + if (format_char == 'n') + if (!add_thousands_grouping(buffer, buf_size)) + return NULL; + + return buffer; } double PyOS_ascii_atof(const char *nptr) { - return PyOS_ascii_strtod(nptr, NULL); + return PyOS_ascii_strtod(nptr, NULL); } |