Internal plumbing changes for float parsing:
- check for nans and infs within PyOS_ascii_strtod
- simplify parsing in PyFloat_FromString, and handle out-of-memory
errors properly
diff --git a/Python/pystrtod.c b/Python/pystrtod.c
index 002714f..b9a33a1 100644
--- a/Python/pystrtod.c
+++ b/Python/pystrtod.c
@@ -94,6 +94,10 @@
decimal_point_pos = NULL;
+ /* Set errno to zero, so that we can distinguish zero results
+ and underflows */
+ errno = 0;
+
/* 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) */
@@ -107,27 +111,53 @@
if (*p == '-') {
negate = 1;
p++;
- } else if (*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;
+ /* Parse infinities and nans */
+ if (*p == 'i' || *p == 'I') {
+ if (PyOS_strnicmp(p, "inf", 3) == 0) {
+ val = Py_HUGE_VAL;
+ if (PyOS_strnicmp(p+3, "inity", 5) == 0)
+ fail_pos = (char *)p+8;
+ else
+ fail_pos = (char *)p+3;
+ goto got_val;
+ }
+ else
+ goto invalid_string;
}
- digits_pos = p;
+#ifdef Py_NAN
+ if (*p == 'n' || *p == 'N') {
+ if (PyOS_strnicmp(p, "nan", 3) == 0) {
+ val = Py_NAN;
+ fail_pos = (char *)p+3;
+ goto got_val;
+ }
+ else
+ goto invalid_string;
+ }
+#endif
- if (decimal_point[0] != '.' ||
+ /* Some platform strtods accept hex floats; Python shouldn't (at the
+ moment), so we check explicitly for strings starting with '0x'. */
+ if (*p == '0' && (*(p+1) == 'x' || *(p+1) == 'X'))
+ goto invalid_string;
+
+ /* Check that what's left begins with a digit or decimal point */
+ if (!ISDIGIT(*p) && *p != '.')
+ goto invalid_string;
+
+ digits_pos = p;
+ if (decimal_point[0] != '.' ||
decimal_point[1] != 0)
{
+ /* Look for a '.' in the input; if present, it'll need to be
+ swapped for the current locale's decimal point before we
+ call strtod. On the other hand, if we find the current
+ locale's decimal point then the input is invalid. */
while (ISDIGIT(*p))
p++;
@@ -135,6 +165,7 @@
{
decimal_point_pos = p++;
+ /* locate end of number */
while (ISDIGIT(*p))
p++;
@@ -147,27 +178,16 @@
end = p;
}
else if (strncmp(p, decimal_point, decimal_point_len) == 0)
- {
/* Python bug #1417699 */
- if (endptr)
- *endptr = (char*)nptr;
- errno = EINVAL;
- return val;
- }
+ goto invalid_string;
/* 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)
- {
+ if (decimal_point_pos) {
char *copy, *c;
-
- /* We need to convert the '.' to the locale specific decimal
- point */
+ /* Create a copy of the input, with the '.' converted to the
+ locale-specific decimal point */
copy = (char *)PyMem_MALLOC(end - digits_pos +
1 + decimal_point_len);
if (copy == NULL) {
@@ -208,8 +228,9 @@
}
if (fail_pos == digits_pos)
- fail_pos = (char *)nptr;
+ goto invalid_string;
+ got_val:
if (negate && fail_pos != nptr)
val = -val;
@@ -217,6 +238,12 @@
*endptr = fail_pos;
return val;
+
+ invalid_string:
+ if (endptr)
+ *endptr = (char*)nptr;
+ errno = EINVAL;
+ return -1.0;
}
#endif