diff options
Diffstat (limited to 'Objects/floatobject.c')
| -rw-r--r-- | Objects/floatobject.c | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/Objects/floatobject.c b/Objects/floatobject.c index 48d29d7042..c876c74063 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -114,7 +114,7 @@ PyFloat_FromDouble(double fval) PyObject * PyFloat_FromString(PyObject *v) { - const char *s, *last, *end; + const char *s, *last, *end, *sp; double x; char buffer[256]; /* for errors */ char *s_buffer = NULL; @@ -146,6 +146,7 @@ PyFloat_FromString(PyObject *v) PyErr_SetString(PyExc_ValueError, "empty string for float()"); goto error; } + sp = s; /* We don't care about overflow or underflow. If the platform supports * them, infinities and signed zeroes (on underflow) are fine. * However, strtod can return 0 for denormalized numbers, where atof @@ -161,7 +162,26 @@ PyFloat_FromString(PyObject *v) byte at the end of the string, when the input is inf(inity). */ if (end > last) end = last; + /* Check for inf and nan. This is done late because it rarely happens. */ if (end == s) { + char *p = (char*)sp; + int sign = 1; + + if (*p == '-') { + sign = -1; + p++; + } + if (*p == '+') { + p++; + } + if (PyOS_strnicmp(p, "inf", 4) == 0) { + return PyFloat_FromDouble(sign * Py_HUGE_VAL); + } +#ifdef Py_NAN + if(PyOS_strnicmp(p, "nan", 4) == 0) { + return PyFloat_FromDouble(Py_NAN); + } +#endif PyOS_snprintf(buffer, sizeof(buffer), "invalid literal for float(): %.200s", s); PyErr_SetString(PyExc_ValueError, buffer); @@ -250,7 +270,9 @@ format_double(char *buf, size_t buflen, double ob_fval, int precision) { register char *cp; char format[32]; - /* Subroutine for float_repr, float_str, and others. + int i; + + /* Subroutine for float_repr, float_str and float_print. We want float numbers to be recognizable as such, i.e., they should contain a decimal point or an exponent. However, %g may print the number as an integer; @@ -271,7 +293,33 @@ format_double(char *buf, size_t buflen, double ob_fval, int precision) *cp++ = '.'; *cp++ = '0'; *cp++ = '\0'; + return; } + /* Checking the next three chars should be more than enough to + * detect inf or nan, even on Windows. We check for inf or nan + * at last because they are rare cases. + */ + for (i=0; *cp != '\0' && i<3; cp++, i++) { + if (isdigit(Py_CHARMASK(*cp)) || *cp == '.') + continue; + /* found something that is neither a digit nor point + * it might be a NaN or INF + */ +#ifdef Py_NAN + if (Py_IS_NAN(ob_fval)) { + strcpy(buf, "nan"); + } + else +#endif + if (Py_IS_INFINITY(ob_fval)) { + cp = buf; + if (*cp == '-') + cp++; + strcpy(cp, "inf"); + } + break; + } + } static void |