bpo-33441: Make the sigset_t converter available in other modules. (GH-6720)

* Expose the sigset_t converter via private API _Py_Sigset_Converter().
* Use Argument Clinic for parsing sigset_t in signalmodule.c.
* Raise ValueError instead OverflowError for integers out of
  the C long range.

Based on patch by Pablo Galindo Salgado.

Author: serhiy-storchaka

Lib/test/test_signal.py

@@ -943,6 +943,10 @@ def test_pthread_sigmask_arguments(self):
         self.assertRaises(OSError, signal.pthread_sigmask, 1700, [])
         with self.assertRaises(ValueError):
             signal.pthread_sigmask(signal.SIG_BLOCK, [signal.NSIG])
+        with self.assertRaises(ValueError):
+            signal.pthread_sigmask(signal.SIG_BLOCK, [0])
+        with self.assertRaises(ValueError):
+            signal.pthread_sigmask(signal.SIG_BLOCK, [1<<1000])
 
     @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
                          'need signal.pthread_sigmask()')

Modules/clinic/signalmodule.c.h

@@ -278,17 +278,17 @@ PyDoc_STRVAR(signal_pthread_sigmask__doc__,
     {"pthread_sigmask", (PyCFunction)signal_pthread_sigmask, METH_FASTCALL, signal_pthread_sigmask__doc__},
 
 static PyObject *
-signal_pthread_sigmask_impl(PyObject *module, int how, PyObject *mask);
+signal_pthread_sigmask_impl(PyObject *module, int how, sigset_t mask);
 
 static PyObject *
 signal_pthread_sigmask(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     int how;
-    PyObject *mask;
+    sigset_t mask;
 
-    if (!_PyArg_ParseStack(args, nargs, "iO:pthread_sigmask",
-        &how, &mask)) {
+    if (!_PyArg_ParseStack(args, nargs, "iO&:pthread_sigmask",
+        &how, _Py_Sigset_Converter, &mask)) {
         goto exit;
     }
     return_value = signal_pthread_sigmask_impl(module, how, mask);
@@ -339,6 +339,24 @@ PyDoc_STRVAR(signal_sigwait__doc__,
 #define SIGNAL_SIGWAIT_METHODDEF    \
     {"sigwait", (PyCFunction)signal_sigwait, METH_O, signal_sigwait__doc__},
 
+static PyObject *
+signal_sigwait_impl(PyObject *module, sigset_t sigset);
+
+static PyObject *
+signal_sigwait(PyObject *module, PyObject *arg)
+{
+    PyObject *return_value = NULL;
+    sigset_t sigset;
+
+    if (!PyArg_Parse(arg, "O&:sigwait", _Py_Sigset_Converter, &sigset)) {
+        goto exit;
+    }
+    return_value = signal_sigwait_impl(module, sigset);
+
+exit:
+    return return_value;
+}
+
 #endif /* defined(HAVE_SIGWAIT) */
 
 #if (defined(HAVE_SIGFILLSET) || defined(MS_WINDOWS))
@@ -379,6 +397,24 @@ PyDoc_STRVAR(signal_sigwaitinfo__doc__,
 #define SIGNAL_SIGWAITINFO_METHODDEF    \
     {"sigwaitinfo", (PyCFunction)signal_sigwaitinfo, METH_O, signal_sigwaitinfo__doc__},
 
+static PyObject *
+signal_sigwaitinfo_impl(PyObject *module, sigset_t sigset);
+
+static PyObject *
+signal_sigwaitinfo(PyObject *module, PyObject *arg)
+{
+    PyObject *return_value = NULL;
+    sigset_t sigset;
+
+    if (!PyArg_Parse(arg, "O&:sigwaitinfo", _Py_Sigset_Converter, &sigset)) {
+        goto exit;
+    }
+    return_value = signal_sigwaitinfo_impl(module, sigset);
+
+exit:
+    return return_value;
+}
+
 #endif /* defined(HAVE_SIGWAITINFO) */
 
 #if defined(HAVE_SIGTIMEDWAIT)
@@ -395,19 +431,18 @@ PyDoc_STRVAR(signal_sigtimedwait__doc__,
     {"sigtimedwait", (PyCFunction)signal_sigtimedwait, METH_FASTCALL, signal_sigtimedwait__doc__},
 
 static PyObject *
-signal_sigtimedwait_impl(PyObject *module, PyObject *sigset,
+signal_sigtimedwait_impl(PyObject *module, sigset_t sigset,
                          PyObject *timeout_obj);
 
 static PyObject *
 signal_sigtimedwait(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    PyObject *sigset;
+    sigset_t sigset;
     PyObject *timeout_obj;
 
-    if (!_PyArg_UnpackStack(args, nargs, "sigtimedwait",
-        2, 2,
-        &sigset, &timeout_obj)) {
+    if (!_PyArg_ParseStack(args, nargs, "O&O:sigtimedwait",
+        _Py_Sigset_Converter, &sigset, &timeout_obj)) {
         goto exit;
     }
     return_value = signal_sigtimedwait_impl(module, sigset, timeout_obj);
@@ -499,4 +534,4 @@ signal_pthread_kill(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 #ifndef SIGNAL_PTHREAD_KILL_METHODDEF
     #define SIGNAL_PTHREAD_KILL_METHODDEF
 #endif /* !defined(SIGNAL_PTHREAD_KILL_METHODDEF) */
-/*[clinic end generated code: output=f35d79e0cfee3f1b input=a9049054013a1b77]*/
+/*[clinic end generated code: output=549f0efdc7405834 input=a9049054013a1b77]*/

Modules/posixmodule.c

@@ -1267,6 +1267,65 @@ PyLong_FromPy_off_t(Py_off_t offset)
 #endif
 }
 
+#ifdef HAVE_SIGSET_T
+/* Convert an iterable of integers to a sigset.
+   Return 1 on success, return 0 and raise an exception on error. */
+int
+_Py_Sigset_Converter(PyObject *obj, void *addr)
+{
+    sigset_t *mask = (sigset_t *)addr;
+    PyObject *iterator, *item;
+    long signum;
+    int overflow;
+
+    if (sigemptyset(mask)) {
+        /* Probably only if mask == NULL. */
+        PyErr_SetFromErrno(PyExc_OSError);
+        return 0;
+    }
+
+    iterator = PyObject_GetIter(obj);
+    if (iterator == NULL) {
+        return 0;
+    }
+
+    while ((item = PyIter_Next(iterator)) != NULL) {
+        signum = PyLong_AsLongAndOverflow(item, &overflow);
+        Py_DECREF(item);
+        if (signum <= 0 || signum >= NSIG) {
+            if (overflow || signum != -1 || !PyErr_Occurred()) {
+                PyErr_Format(PyExc_ValueError,
+                             "signal number %ld out of range", signum);
+            }
+            goto error;
+        }
+        if (sigaddset(mask, (int)signum)) {
+            if (errno != EINVAL) {
+                /* Probably impossible */
+                PyErr_SetFromErrno(PyExc_OSError);
+                goto error;
+            }
+            /* For backwards compatibility, allow idioms such as
+             * `range(1, NSIG)` but warn about invalid signal numbers
+             */
+            const char msg[] =
+                "invalid signal number %ld, please use valid_signals()";
+            if (PyErr_WarnFormat(PyExc_RuntimeWarning, 1, msg, signum)) {
+                goto error;
+            }
+        }
+    }
+    if (!PyErr_Occurred()) {
+        Py_DECREF(iterator);
+        return 1;
+    }
+
+error:
+    Py_DECREF(iterator);
+    return 0;
+}
+#endif /* HAVE_SIGSET_T */
+
 #ifdef MS_WINDOWS
 
 static int

Modules/posixmodule.h

@@ -17,8 +17,17 @@ PyAPI_FUNC(PyObject *) _PyLong_FromGid(gid_t);
 PyAPI_FUNC(int) _Py_Uid_Converter(PyObject *, void *);
 PyAPI_FUNC(int) _Py_Gid_Converter(PyObject *, void *);
 #endif /* MS_WINDOWS */
+
+#if defined(PYPTHREAD_SIGMASK) || defined(HAVE_SIGWAIT) || \
+        defined(HAVE_SIGWAITINFO) || defined(HAVE_SIGTIMEDWAIT)
+# define HAVE_SIGSET_T
 #endif
 
+#ifdef HAVE_SIGSET_T
+PyAPI_FUNC(int) _Py_Sigset_Converter(PyObject *, void *);
+#endif /* HAVE_SIGSET_T */
+#endif /* Py_LIMITED_API */
+
 #ifdef __cplusplus
 }
 #endif