bpo-36974: implement PEP 590 (GH-13185)
Co-authored-by: Jeroen Demeyer <J.Demeyer@UGent.be>
Co-authored-by: Mark Shannon <mark@hotpy.org>
diff --git a/Include/classobject.h b/Include/classobject.h
index 209f0f4..c83303c 100644
--- a/Include/classobject.h
+++ b/Include/classobject.h
@@ -14,6 +14,7 @@
PyObject *im_func; /* The callable object implementing the method */
PyObject *im_self; /* The instance it is bound to */
PyObject *im_weakreflist; /* List of weak references */
+ vectorcallfunc vectorcall;
} PyMethodObject;
PyAPI_DATA(PyTypeObject) PyMethod_Type;
diff --git a/Include/cpython/abstract.h b/Include/cpython/abstract.h
index b8b2d44..7099178 100644
--- a/Include/cpython/abstract.h
+++ b/Include/cpython/abstract.h
@@ -47,7 +47,7 @@
/* Suggested size (number of positional arguments) for arrays of PyObject*
allocated on a C stack to avoid allocating memory on the heap memory. Such
array is used to pass positional arguments to call functions of the
- _PyObject_FastCall() family.
+ _PyObject_Vectorcall() family.
The size is chosen to not abuse the C stack and so limit the risk of stack
overflow. The size is also chosen to allow using the small stack for most
@@ -56,50 +56,103 @@
#define _PY_FASTCALL_SMALL_STACK 5
/* Return 1 if callable supports FASTCALL calling convention for positional
- arguments: see _PyObject_FastCallDict() and _PyObject_FastCallKeywords() */
+ arguments: see _PyObject_Vectorcall() and _PyObject_FastCallDict() */
PyAPI_FUNC(int) _PyObject_HasFastCall(PyObject *callable);
-/* Call the callable object 'callable' with the "fast call" calling convention:
- args is a C array for positional arguments (nargs is the number of
- positional arguments), kwargs is a dictionary for keyword arguments.
+PyAPI_FUNC(PyObject *) _Py_CheckFunctionResult(PyObject *callable,
+ PyObject *result,
+ const char *where);
- If nargs is equal to zero, args can be NULL. kwargs can be NULL.
- nargs must be greater or equal to zero.
+/* === Vectorcall protocol (PEP 590) ============================= */
+
+/* Call callable using tp_call. Arguments are like _PyObject_Vectorcall()
+ or _PyObject_FastCallDict() (both forms are supported),
+ except that nargs is plainly the number of arguments without flags. */
+PyAPI_FUNC(PyObject *) _PyObject_MakeTpCall(
+ PyObject *callable,
+ PyObject *const *args, Py_ssize_t nargs,
+ PyObject *keywords);
+
+#define PY_VECTORCALL_ARGUMENTS_OFFSET ((size_t)1 << (8 * sizeof(size_t) - 1))
+
+static inline Py_ssize_t
+PyVectorcall_NARGS(size_t n)
+{
+ return n & ~PY_VECTORCALL_ARGUMENTS_OFFSET;
+}
+
+static inline vectorcallfunc
+_PyVectorcall_Function(PyObject *callable)
+{
+ PyTypeObject *tp = Py_TYPE(callable);
+ if (!PyType_HasFeature(tp, _Py_TPFLAGS_HAVE_VECTORCALL)) {
+ return NULL;
+ }
+ assert(PyCallable_Check(callable));
+ Py_ssize_t offset = tp->tp_vectorcall_offset;
+ assert(offset > 0);
+ vectorcallfunc *ptr = (vectorcallfunc *)(((char *)callable) + offset);
+ return *ptr;
+}
+
+/* Call the callable object 'callable' with the "vectorcall" calling
+ convention.
+
+ args is a C array for positional arguments.
+
+ nargsf is the number of positional arguments plus optionally the flag
+ PY_VECTORCALL_ARGUMENTS_OFFSET which means that the caller is allowed to
+ modify args[-1].
+
+ kwnames is a tuple of keyword names. The values of the keyword arguments
+ are stored in "args" after the positional arguments (note that the number
+ of keyword arguments does not change nargsf). kwnames can also be NULL if
+ there are no keyword arguments.
+
+ keywords must only contains str strings (no subclass), and all keys must
+ be unique.
Return the result on success. Raise an exception and return NULL on
error. */
+static inline PyObject *
+_PyObject_Vectorcall(PyObject *callable, PyObject *const *args,
+ size_t nargsf, PyObject *kwnames)
+{
+ assert(kwnames == NULL || PyTuple_Check(kwnames));
+ assert(args != NULL || PyVectorcall_NARGS(nargsf) == 0);
+ vectorcallfunc func = _PyVectorcall_Function(callable);
+ if (func == NULL) {
+ Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
+ return _PyObject_MakeTpCall(callable, args, nargs, kwnames);
+ }
+ PyObject *res = func(callable, args, nargsf, kwnames);
+ return _Py_CheckFunctionResult(callable, res, NULL);
+}
+
+/* Same as _PyObject_Vectorcall except that keyword arguments are passed as
+ dict, which may be NULL if there are no keyword arguments. */
PyAPI_FUNC(PyObject *) _PyObject_FastCallDict(
PyObject *callable,
PyObject *const *args,
- Py_ssize_t nargs,
+ size_t nargsf,
PyObject *kwargs);
-/* Call the callable object 'callable' with the "fast call" calling convention:
- args is a C array for positional arguments followed by values of
- keyword arguments. Keys of keyword arguments are stored as a tuple
- of strings in kwnames. nargs is the number of positional parameters at
- the beginning of stack. The size of kwnames gives the number of keyword
- values in the stack after positional arguments.
+/* Call "callable" (which must support vectorcall) with positional arguments
+ "tuple" and keyword arguments "dict". "dict" may also be NULL */
+PyAPI_FUNC(PyObject *) PyVectorcall_Call(PyObject *callable, PyObject *tuple, PyObject *dict);
- kwnames must only contains str strings, no subclass, and all keys must
- be unique.
+/* Same as _PyObject_Vectorcall except without keyword arguments */
+static inline PyObject *
+_PyObject_FastCall(PyObject *func, PyObject *const *args, Py_ssize_t nargs)
+{
+ return _PyObject_Vectorcall(func, args, (size_t)nargs, NULL);
+}
- If nargs is equal to zero and there is no keyword argument (kwnames is
- NULL or its size is zero), args can be NULL.
-
- Return the result on success. Raise an exception and return NULL on
- error. */
-PyAPI_FUNC(PyObject *) _PyObject_FastCallKeywords(
- PyObject *callable,
- PyObject *const *args,
- Py_ssize_t nargs,
- PyObject *kwnames);
-
-#define _PyObject_FastCall(func, args, nargs) \
- _PyObject_FastCallDict((func), (args), (nargs), NULL)
-
-#define _PyObject_CallNoArg(func) \
- _PyObject_FastCallDict((func), NULL, 0, NULL)
+/* Call a callable without any arguments */
+static inline PyObject *
+_PyObject_CallNoArg(PyObject *func) {
+ return _PyObject_Vectorcall(func, NULL, 0, NULL);
+}
PyAPI_FUNC(PyObject *) _PyObject_Call_Prepend(
PyObject *callable,
@@ -113,10 +166,6 @@
PyObject *const *args,
Py_ssize_t nargs);
-PyAPI_FUNC(PyObject *) _Py_CheckFunctionResult(PyObject *callable,
- PyObject *result,
- const char *where);
-
/* Like PyObject_CallMethod(), but expect a _Py_Identifier*
as the method name. */
PyAPI_FUNC(PyObject *) _PyObject_CallMethodId(PyObject *obj,
diff --git a/Include/cpython/object.h b/Include/cpython/object.h
index ba52a48..a65aaf6 100644
--- a/Include/cpython/object.h
+++ b/Include/cpython/object.h
@@ -55,6 +55,9 @@
typedef int (*getbufferproc)(PyObject *, Py_buffer *, int);
typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
+typedef PyObject *(*vectorcallfunc)(PyObject *callable, PyObject *const *args,
+ size_t nargsf, PyObject *kwnames);
+
/* Maximum number of dimensions */
#define PyBUF_MAX_NDIM 64
@@ -167,12 +170,9 @@
releasebufferproc bf_releasebuffer;
} PyBufferProcs;
-/* We can't provide a full compile-time check that limited-API
- users won't implement tp_print. However, not defining printfunc
- and making tp_print of a different function pointer type
- if Py_LIMITED_API is set should at least cause a warning
- in most cases. */
-typedef int (*printfunc)(PyObject *, FILE *, int);
+/* Allow printfunc in the tp_vectorcall_offset slot for
+ * backwards-compatibility */
+typedef Py_ssize_t printfunc;
typedef struct _typeobject {
PyObject_VAR_HEAD
@@ -182,7 +182,7 @@
/* Methods to implement standard operations */
destructor tp_dealloc;
- printfunc tp_print;
+ Py_ssize_t tp_vectorcall_offset;
getattrfunc tp_getattr;
setattrfunc tp_setattr;
PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2)
@@ -254,6 +254,7 @@
unsigned int tp_version_tag;
destructor tp_finalize;
+ vectorcallfunc tp_vectorcall;
#ifdef COUNT_ALLOCS
/* these must be last and never explicitly initialized */
diff --git a/Include/descrobject.h b/Include/descrobject.h
index 73bbb3f..3db0963 100644
--- a/Include/descrobject.h
+++ b/Include/descrobject.h
@@ -53,6 +53,7 @@
typedef struct {
PyDescr_COMMON;
PyMethodDef *d_method;
+ vectorcallfunc vectorcall;
} PyMethodDescrObject;
typedef struct {
@@ -92,7 +93,7 @@
#ifndef Py_LIMITED_API
PyAPI_FUNC(PyObject *) _PyMethodDescr_FastCallKeywords(
- PyObject *descrobj, PyObject *const *stack, Py_ssize_t nargs, PyObject *kwnames);
+ PyObject *descrobj, PyObject *const *args, size_t nargsf, PyObject *kwnames);
PyAPI_FUNC(PyObject *) PyDescr_NewWrapper(PyTypeObject *,
struct wrapperbase *, void *);
#define PyDescr_IsData(d) (Py_TYPE(d)->tp_descr_set != NULL)
diff --git a/Include/funcobject.h b/Include/funcobject.h
index 86674ac..7ba000e 100644
--- a/Include/funcobject.h
+++ b/Include/funcobject.h
@@ -32,6 +32,7 @@
PyObject *func_module; /* The __module__ attribute, can be anything */
PyObject *func_annotations; /* Annotations, a dict or NULL */
PyObject *func_qualname; /* The qualified name */
+ vectorcallfunc vectorcall;
/* Invariant:
* func_closure contains the bindings for func_code->co_freevars, so
@@ -68,7 +69,7 @@
PyAPI_FUNC(PyObject *) _PyFunction_FastCallKeywords(
PyObject *func,
PyObject *const *stack,
- Py_ssize_t nargs,
+ size_t nargsf,
PyObject *kwnames);
#endif
diff --git a/Include/methodobject.h b/Include/methodobject.h
index ea35d86..5dbe214 100644
--- a/Include/methodobject.h
+++ b/Include/methodobject.h
@@ -49,7 +49,7 @@
PyAPI_FUNC(PyObject *) _PyCFunction_FastCallKeywords(PyObject *func,
PyObject *const *stack,
- Py_ssize_t nargs,
+ size_t nargsf,
PyObject *kwnames);
#endif
@@ -105,6 +105,7 @@
PyObject *m_self; /* Passed as 'self' arg to the C func, can be NULL */
PyObject *m_module; /* The __module__ attribute, can be anything */
PyObject *m_weakreflist; /* List of weak references */
+ vectorcallfunc vectorcall;
} PyCFunctionObject;
PyAPI_FUNC(PyObject *) _PyMethodDef_RawFastCallDict(
diff --git a/Include/object.h b/Include/object.h
index d5d98d3..11ba2bb 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -291,6 +291,11 @@
/* Set if the type allows subclassing */
#define Py_TPFLAGS_BASETYPE (1UL << 10)
+/* Set if the type implements the vectorcall protocol (PEP 590) */
+#ifndef Py_LIMITED_API
+#define _Py_TPFLAGS_HAVE_VECTORCALL (1UL << 11)
+#endif
+
/* Set if the type is 'ready' -- fully initialized */
#define Py_TPFLAGS_READY (1UL << 12)