bpo-33738: Fix macros which contradict PEP 384 (GH-7477)
During development of the limited API support for PySide,
we saw an error in a macro that accessed a type field.
This patch fixes the 7 errors in the Python headers.
Macros which were not written as capitals were implemented
as function.
To do the necessary analysis again, a script was included that
parses all headers and looks for "->tp_" in serctions which can
be reached with active limited API.
It is easily possible to call this script as a test.
Error listing:
../../Include/objimpl.h:243
#define PyObject_IS_GC(o) (PyType_IS_GC(Py_TYPE(o)) && \
(Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o)))
Action: commented only
../../Include/objimpl.h:362
#define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0)
Action: commented only
../../Include/objimpl.h:364
#define PyObject_GET_WEAKREFS_LISTPTR(o) \
((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset))
Action: commented only
../../Include/pyerrors.h:143
#define PyExceptionClass_Name(x) \
((char *)(((PyTypeObject*)(x))->tp_name))
Action: implemented function
../../Include/abstract.h:593
#define PyIter_Check(obj) \
((obj)->ob_type->tp_iternext != NULL && \
(obj)->ob_type->tp_iternext != &_PyObject_NextNotImplemented)
Action: implemented function
../../Include/abstract.h:713
#define PyIndex_Check(obj) \
((obj)->ob_type->tp_as_number != NULL && \
(obj)->ob_type->tp_as_number->nb_index != NULL)
Action: implemented function
../../Include/abstract.h:924
#define PySequence_ITEM(o, i)\
( Py_TYPE(o)->tp_as_sequence->sq_item(o, i) )
Action: commented only
diff --git a/Include/abstract.h b/Include/abstract.h
index 4088f75..e7bc2d2 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -590,9 +590,16 @@
returns itself. */
PyAPI_FUNC(PyObject *) PyObject_GetIter(PyObject *);
+/* Returns 1 if the object 'obj' provides iterator protocols, and 0 otherwise.
+
+ This function always succeeds. */
+#ifndef Py_LIMITED_API
#define PyIter_Check(obj) \
((obj)->ob_type->tp_iternext != NULL && \
(obj)->ob_type->tp_iternext != &_PyObject_NextNotImplemented)
+#else
+PyAPI_FUNC(int) PyIter_Check(PyObject*);
+#endif
/* Takes an iterator object and calls its tp_iternext slot,
returning the next value.
@@ -710,9 +717,15 @@
This is the equivalent of the Python expression: o1 | o2. */
PyAPI_FUNC(PyObject *) PyNumber_Or(PyObject *o1, PyObject *o2);
+/* Returns 1 if obj is an index integer (has the nb_index slot of the
+ tp_as_number structure filled in), and 0 otherwise. */
+#ifndef Py_LIMITED_API
#define PyIndex_Check(obj) \
((obj)->ob_type->tp_as_number != NULL && \
(obj)->ob_type->tp_as_number->nb_index != NULL)
+#else
+PyAPI_FUNC(int) PyIndex_Check(PyObject *);
+#endif
/* Returns the object 'o' converted to a Python int, or NULL with an exception
raised on failure. */
@@ -921,8 +934,10 @@
/* Assume tp_as_sequence and sq_item exist and that 'i' does not
need to be corrected for a negative index. */
+#ifndef Py_LIMITED_API
#define PySequence_ITEM(o, i)\
( Py_TYPE(o)->tp_as_sequence->sq_item(o, i) )
+#endif
/* Return a pointer to the underlying item array for
an object retured by PySequence_Fast */
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 057bb50..a38906c 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -240,8 +240,10 @@
#define PyType_IS_GC(t) PyType_HasFeature((t), Py_TPFLAGS_HAVE_GC)
/* Test if an object has a GC head */
+#ifndef Py_LIMITED_API
#define PyObject_IS_GC(o) (PyType_IS_GC(Py_TYPE(o)) && \
(Py_TYPE(o)->tp_is_gc == NULL || Py_TYPE(o)->tp_is_gc(o)))
+#endif
PyAPI_FUNC(PyVarObject *) _PyObject_GC_Resize(PyVarObject *, Py_ssize_t);
#define PyObject_GC_Resize(type, op, n) \
@@ -359,10 +361,12 @@
/* Test if a type supports weak references */
+#ifndef Py_LIMITED_API
#define PyType_SUPPORTS_WEAKREFS(t) ((t)->tp_weaklistoffset > 0)
#define PyObject_GET_WEAKREFS_LISTPTR(o) \
((PyObject **) (((char *) (o)) + Py_TYPE(o)->tp_weaklistoffset))
+#endif
#ifdef __cplusplus
}
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index f289471..a9929f5 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -140,8 +140,12 @@
#define PyExceptionInstance_Check(x) \
PyType_FastSubclass((x)->ob_type, Py_TPFLAGS_BASE_EXC_SUBCLASS)
+#ifndef Py_LIMITED_API
#define PyExceptionClass_Name(x) \
((char *)(((PyTypeObject*)(x))->tp_name))
+#else
+ PyAPI_FUNC(char *) PyExceptionClass_Name(PyObject*);
+#endif
#define PyExceptionInstance_Class(x) ((PyObject*)((x)->ob_type))