Make floating-point exception error messages slightly more verbose: in
particular, the error message now allows one to distinguish between a
ValueError arising from a singularity (e.g. log(0.)), which would
usually produce +-infinity in non-stop mode, and a ValueError resulting
from an invalid input (e.g. sqrt(-1.)), which would normally produce a
NaN in non-stop mode.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 3cf1133..aa38691 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -174,18 +174,21 @@
PyFPE_START_PROTECT("in math_1", return 0);
r = (*func)(x);
PyFPE_END_PROTECT(r);
- if (Py_IS_NAN(r)) {
- if (!Py_IS_NAN(x))
- errno = EDOM;
- else
- errno = 0;
+ if (Py_IS_NAN(r) && !Py_IS_NAN(x)) {
+ PyErr_SetString(PyExc_ValueError,
+ "math domain error (invalid argument)");
+ return NULL;
}
- else if (Py_IS_INFINITY(r)) {
- if (Py_IS_FINITE(x))
- errno = can_overflow ? ERANGE : EDOM;
- else
- errno = 0;
+ if (Py_IS_INFINITY(r) && Py_IS_FINITE(x)) {
+ if (can_overflow)
+ PyErr_SetString(PyExc_OverflowError,
+ "math range error (overflow)");
+ else
+ PyErr_SetString(PyExc_ValueError,
+ "math domain error (singularity)");
+ return NULL;
}
+ /* on most machines, errno should be 0 at this point */
if (errno && is_error(r))
return NULL;
else