Fix function signature casts in PyMethodDef structs that lead to warn…

…ings in gcc-8 (and actually make use of the warnings in gcc-8).

Cython/Compiler/Code.py

@@ -2195,9 +2195,12 @@ def put_pymethoddef(self, entry, term, allow_skip=True):
                 method_flags += [method_coexist]
             func_ptr = entry.func_cname
             # Add required casts, but try not to shadow real warnings.
-            cast = '__Pyx_PyCFunctionFast' if 'METH_FASTCALL' in method_flags else 'PyCFunction'
-            if 'METH_KEYWORDS' in method_flags:
-                cast += 'WithKeywords'
+            if 'METH_NOARGS' in method_flags:
+                cast = 'PyNoArgsFunction'
+            else:
+                cast = '__Pyx_PyCFunctionFast' if 'METH_FASTCALL' in method_flags else 'PyCFunction'
+                if 'METH_KEYWORDS' in method_flags:
+                    cast += 'WithKeywords'
             if cast != 'PyCFunction':
                 func_ptr = '(void*)(%s)%s' % (cast, func_ptr)
             self.putln(

Cython/Utility/AsyncGen.c

@@ -259,6 +259,11 @@ __Pyx_async_gen_anext(PyObject *g)
     return __Pyx_async_gen_asend_new(o, NULL);
 }
 
+static PyObject *
+__Pyx_async_gen_anext_method(PyObject *g, CYTHON_UNUSED PyObject *arg) {
+    return __Pyx_async_gen_anext(g);
+}
+
 
 static PyObject *
 __Pyx_async_gen_asend(__pyx_PyAsyncGenObject *o, PyObject *arg)
@@ -279,6 +284,7 @@ __Pyx_async_gen_aclose(__pyx_PyAsyncGenObject *o, CYTHON_UNUSED PyObject *arg)
     return __Pyx_async_gen_athrow_new(o, NULL);
 }
 
+
 static PyObject *
 __Pyx_async_gen_athrow(__pyx_PyAsyncGenObject *o, PyObject *args)
 {
@@ -289,6 +295,12 @@ __Pyx_async_gen_athrow(__pyx_PyAsyncGenObject *o, PyObject *args)
 }
 
 
+static PyObject *
+__Pyx_async_gen_self_method(PyObject *g, CYTHON_UNUSED PyObject *arg) {
+    return __Pyx_NewRef(g);
+}
+
+
 static PyGetSetDef __Pyx_async_gen_getsetlist[] = {
     {(char*) "__name__", (getter)__Pyx_Coroutine_get_name, (setter)__Pyx_Coroutine_set_name,
      (char*) PyDoc_STR("name of the async generator"), 0},
@@ -328,8 +340,8 @@ static PyMethodDef __Pyx_async_gen_methods[] = {
     {"asend", (PyCFunction)__Pyx_async_gen_asend, METH_O, __Pyx_async_asend_doc},
     {"athrow",(PyCFunction)__Pyx_async_gen_athrow, METH_VARARGS, __Pyx_async_athrow_doc},
     {"aclose", (PyCFunction)__Pyx_async_gen_aclose, METH_NOARGS, __Pyx_async_aclose_doc},
-    {"__aiter__", (PyCFunction)PyObject_SelfIter, METH_NOARGS, __Pyx_async_aiter_doc},
-    {"__anext__", (PyCFunction)__Pyx_async_gen_anext, METH_NOARGS, __Pyx_async_anext_doc},
+    {"__aiter__", (PyCFunction)__Pyx_async_gen_self_method, METH_NOARGS, __Pyx_async_aiter_doc},
+    {"__anext__", (PyCFunction)__Pyx_async_gen_anext_method, METH_NOARGS, __Pyx_async_anext_doc},
     {0, 0, 0, 0}        /* Sentinel */
 };
 
@@ -563,7 +575,7 @@ static PyMethodDef __Pyx_async_gen_asend_methods[] = {
     {"send", (PyCFunction)__Pyx_async_gen_asend_send, METH_O, __Pyx_async_gen_send_doc},
     {"throw", (PyCFunction)__Pyx_async_gen_asend_throw, METH_VARARGS, __Pyx_async_gen_throw_doc},
     {"close", (PyCFunction)__Pyx_async_gen_asend_close, METH_NOARGS, __Pyx_async_gen_close_doc},
-    {"__await__", (PyCFunction)PyObject_SelfIter, METH_NOARGS, __Pyx_async_gen_await_doc},
+    {"__await__", (PyCFunction)__Pyx_async_gen_self_method, METH_NOARGS, __Pyx_async_gen_await_doc},
     {0, 0, 0, 0}        /* Sentinel */
 };
 
@@ -952,7 +964,7 @@ static PyMethodDef __Pyx_async_gen_athrow_methods[] = {
     {"send", (PyCFunction)__Pyx_async_gen_athrow_send, METH_O, __Pyx_async_gen_send_doc},
     {"throw", (PyCFunction)__Pyx_async_gen_athrow_throw, METH_VARARGS, __Pyx_async_gen_throw_doc},
     {"close", (PyCFunction)__Pyx_async_gen_athrow_close, METH_NOARGS, __Pyx_async_gen_close_doc},
-    {"__await__", (PyCFunction)PyObject_SelfIter, METH_NOARGS, __Pyx_async_gen_await_doc},
+    {"__await__", (PyCFunction)__Pyx_async_gen_self_method, METH_NOARGS, __Pyx_async_gen_await_doc},
     {0, 0, 0, 0}        /* Sentinel */
 };
 

Cython/Utility/Coroutine.c

@@ -438,7 +438,7 @@ typedef struct {
     PyObject *coroutine;
 } __pyx_CoroutineAwaitObject;
 
-static PyObject *__Pyx_CoroutineAwait_Close(__pyx_CoroutineAwaitObject *self); /*proto*/
+static PyObject *__Pyx_CoroutineAwait_Close(__pyx_CoroutineAwaitObject *self, PyObject *arg); /*proto*/
 static PyObject *__Pyx_CoroutineAwait_Throw(__pyx_CoroutineAwaitObject *self, PyObject *args); /*proto*/
 
 
@@ -831,7 +831,7 @@ static int __Pyx_Coroutine_CloseIter(__pyx_CoroutineObject *gen, PyObject *yf) {
             return -1;
     } else
     if (__Pyx_CoroutineAwait_CheckExact(yf)) {
-        retval = __Pyx_CoroutineAwait_Close((__pyx_CoroutineAwaitObject*)yf);
+        retval = __Pyx_CoroutineAwait_Close((__pyx_CoroutineAwaitObject*)yf, NULL);
         if (!retval)
             return -1;
     } else
@@ -905,6 +905,10 @@ static PyObject *__Pyx_Generator_Next(PyObject *self) {
     return __Pyx_Coroutine_SendEx(gen, Py_None, 0);
 }
 
+static PyObject *__Pyx_Coroutine_Close_Method(PyObject *self, CYTHON_UNUSED PyObject *arg) {
+    return __Pyx_Coroutine_Close(self);
+}
+
 static PyObject *__Pyx_Coroutine_Close(PyObject *self) {
     __pyx_CoroutineObject *gen = (__pyx_CoroutineObject *) self;
     PyObject *retval, *raised_exception;
@@ -1362,7 +1366,7 @@ static PyObject *__Pyx_CoroutineAwait_Throw(__pyx_CoroutineAwaitObject *self, Py
     return __Pyx_Coroutine_Throw(self->coroutine, args);
 }
 
-static PyObject *__Pyx_CoroutineAwait_Close(__pyx_CoroutineAwaitObject *self) {
+static PyObject *__Pyx_CoroutineAwait_Close(__pyx_CoroutineAwaitObject *self, CYTHON_UNUSED PyObject *arg) {
     return __Pyx_Coroutine_Close(self->coroutine);
 }
 
@@ -1488,7 +1492,7 @@ static PyMethodDef __pyx_Coroutine_methods[] = {
      (char*) PyDoc_STR("send(arg) -> send 'arg' into coroutine,\nreturn next iterated value or raise StopIteration.")},
     {"throw", (PyCFunction) __Pyx_Coroutine_Throw, METH_VARARGS,
      (char*) PyDoc_STR("throw(typ[,val[,tb]]) -> raise exception in coroutine,\nreturn next iterated value or raise StopIteration.")},
-    {"close", (PyCFunction) __Pyx_Coroutine_Close, METH_NOARGS,
+    {"close", (PyCFunction) __Pyx_Coroutine_Close_Method, METH_NOARGS,
      (char*) PyDoc_STR("close() -> raise GeneratorExit inside coroutine.")},
 #if PY_VERSION_HEX < 0x030500B1
     {"__await__", (PyCFunction) __Pyx_Coroutine_await, METH_NOARGS,
@@ -1718,7 +1722,7 @@ static PyMethodDef __pyx_Generator_methods[] = {
      (char*) PyDoc_STR("send(arg) -> send 'arg' into generator,\nreturn next yielded value or raise StopIteration.")},
     {"throw", (PyCFunction) __Pyx_Coroutine_Throw, METH_VARARGS,
      (char*) PyDoc_STR("throw(typ[,val[,tb]]) -> raise exception in generator,\nreturn next yielded value or raise StopIteration.")},
-    {"close", (PyCFunction) __Pyx_Coroutine_Close, METH_NOARGS,
+    {"close", (PyCFunction) __Pyx_Coroutine_Close_Method, METH_NOARGS,
      (char*) PyDoc_STR("close() -> raise GeneratorExit inside generator.")},
     {0, 0, 0, 0}
 };