diff options
Diffstat (limited to 'Include')
| -rw-r--r-- | Include/pyport.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Include/pyport.h b/Include/pyport.h index a831b26..b311bd8 100644 --- a/Include/pyport.h +++ b/Include/pyport.h @@ -287,6 +287,41 @@ extern "C" { errno = ERANGE; \ } while(0) +/* Py_ADJUST_ERANGE1(x) + * Py_ADJUST_ERANGE2(x, y) + * Set errno to 0 before calling a libm function, and invoke one of these + * macros after, passing the function result(s) (Py_ADJUST_ERANGE2 is useful + * for functions returning complex results). This makes two kinds of + * adjustments to errno: (A) If it looks like the platform libm set + * errno=ERANGE due to underflow, clear errno. (B) If it looks like the + * platform libm overflowed but didn't set errno, force errno to ERANGE. In + * effect, we're trying to force a useful implementation of C89 errno + * behavior. + * Caution: + * This isn't reliable. See Py_OVERFLOWED comments. + * X and Y may be evaluated more than once. + */ +#define Py_ADJUST_ERANGE1(X) \ + do { \ + if (errno == 0) { \ + if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL) \ + errno = ERANGE; \ + } \ + else if (errno == ERANGE && (X) == 0.0) \ + errno = 0; \ + } while(0) + +#define Py_ADJUST_ERANGE2(X, Y) \ + do { \ + if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL || \ + (Y) == Py_HUGE_VAL || (Y) == -Py_HUGE_VAL) { \ + if (errno == 0) \ + errno = ERANGE; \ + } \ + else if (errno == ERANGE) \ + errno = 0; \ + } while(0) + /************************************************************************** Prototypes that are missing from the standard include files on some systems (and possibly only some versions of such systems.) |