PyObject *globalsns,
PyObject *builtinsns);
-
-/* "Stateless" code is a function or code object which does not rely on
- * external state or internal state. It may rely on arguments and
- * builtins, but not globals or a closure. Thus it does not rely
- * on __globals__ or __closure__, and a stateless function
- * is equivalent to its code object.
- *
- * Stateless code also does not keep any persistent state
- * of its own, so it can't have any executors, monitoring,
- * instrumentation, or "extras" (i.e. co_extra).
- *
- * Stateless code may create nested functions, including closures.
- * However, nested functions must themselves be stateless, except they
- * *can* close on the enclosing locals.
- *
- * Stateless code may return any value, including nested functions and closures.
- *
- * Stateless code that takes no arguments and doesn't return anything
- * may be treated like a script.
- *
- * We consider stateless code to be "portable" if it does not return any
- * any object that holds a reference to any of the code's locals. Thus
- * generators and coroutines are not portable. Likewise a function
- * that returns a closure is not portable. The concept of
- * portability is useful in cases where the code is run
- * in a different execution context than where
- * the return value will be used. */
-
-PyAPI_FUNC(int) _PyCode_CheckNoInternalState(PyCodeObject *, const char **);
-PyAPI_FUNC(int) _PyCode_CheckNoExternalState(
- PyCodeObject *,
- _PyCode_var_counts_t *,
- const char **);
-PyAPI_FUNC(int) _PyCode_VerifyStateless(
- PyThreadState *,
- PyCodeObject *,
- PyObject *globalnames,
- PyObject *globalsns,
- PyObject *builtinsns);
-
-PyAPI_FUNC(int) _PyCode_CheckPureFunction(PyCodeObject *, const char **);
PyAPI_FUNC(int) _PyCode_ReturnsOnlyNone(PyCodeObject *);
extern PyObject *_Py_set_function_type_params(
PyThreadState* unused, PyObject *func, PyObject *type_params);
-
-/* See pycore_code.h for explanation about what "stateless" means. */
-
-PyAPI_FUNC(int)
-_PyFunction_VerifyStateless(PyThreadState *, PyObject *);
-
-
#ifdef __cplusplus
}
#endif
#define IS_RETURN_OPCODE(opcode) \
(opcode == RETURN_VALUE)
-#define IS_RAISE_OPCODE(opcode) \
- (opcode == RAISE_VARARGS || opcode == RERAISE)
/* Flags used in the oparg for MAKE_FUNCTION */
*NESTED_FUNCTIONS,
]
-STATELESS_FUNCTIONS = [
- spam,
- spam_minimal,
- spam_with_builtins,
- spam_args_attrs_and_builtins,
- spam_returns_arg,
- spam_annotated,
- spam_with_inner_not_closure,
- spam_with_inner_closure,
- spam_N,
- spam_C,
- spam_NN,
- spam_NC,
- spam_CN,
- spam_CC,
- eggs_nested,
- eggs_nested_N,
- ham_nested,
- ham_C_nested
-]
-STATELESS_CODE = [
- *STATELESS_FUNCTIONS,
- spam_with_globals_and_builtins,
- spam_full,
-]
-
# generators
import _testinternalcapi
except ModuleNotFoundError:
_testinternalcapi = None
-import test._code_definitions as defs
COPY_FREE_VARS = opmap['COPY_FREE_VARS']
VARARGS = CO_FAST_LOCAL | CO_FAST_ARG_VAR | CO_FAST_ARG_POS
VARKWARGS = CO_FAST_LOCAL | CO_FAST_ARG_VAR | CO_FAST_ARG_KW
+ import test._code_definitions as defs
funcs = {
defs.spam_minimal: {},
defs.spam_with_builtins: {
},
}
+ import test._code_definitions as defs
funcs = {
defs.spam_minimal: new_var_counts(),
defs.spam_with_builtins: new_var_counts(
counts = _testinternalcapi.get_code_var_counts(func.__code__)
self.assertEqual(counts, expected)
- func = defs.spam_with_globals_and_builtins
+ def func_with_globals_and_builtins():
+ mod1 = _testinternalcapi
+ mod2 = dis
+ mods = (mod1, mod2)
+ checks = tuple(callable(m) for m in mods)
+ return callable(mod2), tuple(mods), list(mods), checks
+
+ func = func_with_globals_and_builtins
with self.subTest(f'{func} code'):
expected = new_var_counts(
- purelocals=5,
- globalvars=6,
+ purelocals=4,
+ globalvars=5,
)
counts = _testinternalcapi.get_code_var_counts(func.__code__)
self.assertEqual(counts, expected)
with self.subTest(f'{func} with own globals and builtins'):
expected = new_var_counts(
- purelocals=5,
- globalvars=(2, 4),
+ purelocals=4,
+ globalvars=(2, 3),
)
counts = _testinternalcapi.get_code_var_counts(func)
self.assertEqual(counts, expected)
with self.subTest(f'{func} without globals'):
expected = new_var_counts(
- purelocals=5,
- globalvars=(0, 4, 2),
+ purelocals=4,
+ globalvars=(0, 3, 2),
)
counts = _testinternalcapi.get_code_var_counts(func, globalsns={})
self.assertEqual(counts, expected)
with self.subTest(f'{func} without both'):
expected = new_var_counts(
- purelocals=5,
- globalvars=6,
+ purelocals=4,
+ globalvars=5,
)
counts = _testinternalcapi.get_code_var_counts(func, globalsns={},
builtinsns={})
with self.subTest(f'{func} without builtins'):
expected = new_var_counts(
- purelocals=5,
- globalvars=(2, 0, 4),
+ purelocals=4,
+ globalvars=(2, 0, 3),
)
counts = _testinternalcapi.get_code_var_counts(func, builtinsns={})
self.assertEqual(counts, expected)
- @unittest.skipIf(_testinternalcapi is None, "missing _testinternalcapi")
- def test_stateless(self):
- self.maxDiff = None
-
- for func in defs.STATELESS_CODE:
- with self.subTest((func, '(code)')):
- _testinternalcapi.verify_stateless_code(func.__code__)
- for func in defs.STATELESS_FUNCTIONS:
- with self.subTest((func, '(func)')):
- _testinternalcapi.verify_stateless_code(func)
-
- for func in defs.FUNCTIONS:
- if func not in defs.STATELESS_CODE:
- with self.subTest((func, '(code)')):
- with self.assertRaises(Exception):
- _testinternalcapi.verify_stateless_code(func.__code__)
-
- if func not in defs.STATELESS_FUNCTIONS:
- with self.subTest((func, '(func)')):
- with self.assertRaises(Exception):
- _testinternalcapi.verify_stateless_code(func)
-
def isinterned(s):
return s is sys.intern(('_' + s + '_')[1:-1])
return NULL;
}
-static PyObject *
-verify_stateless_code(PyObject *self, PyObject *args, PyObject *kwargs)
-{
- PyThreadState *tstate = _PyThreadState_GET();
- PyObject *codearg;
- PyObject *globalnames = NULL;
- PyObject *globalsns = NULL;
- PyObject *builtinsns = NULL;
- static char *kwlist[] = {"code", "globalnames",
- "globalsns", "builtinsns", NULL};
- if (!PyArg_ParseTupleAndKeywords(args, kwargs,
- "O|O!O!O!:get_code_var_counts", kwlist,
- &codearg, &PySet_Type, &globalnames,
- &PyDict_Type, &globalsns, &PyDict_Type, &builtinsns))
- {
- return NULL;
- }
- if (PyFunction_Check(codearg)) {
- if (globalsns == NULL) {
- globalsns = PyFunction_GET_GLOBALS(codearg);
- }
- if (builtinsns == NULL) {
- builtinsns = PyFunction_GET_BUILTINS(codearg);
- }
- codearg = PyFunction_GET_CODE(codearg);
- }
- else if (!PyCode_Check(codearg)) {
- PyErr_SetString(PyExc_TypeError,
- "argument must be a code object or a function");
- return NULL;
- }
- PyCodeObject *code = (PyCodeObject *)codearg;
-
- if (_PyCode_VerifyStateless(
- tstate, code, globalnames, globalsns, builtinsns) < 0)
- {
- return NULL;
- }
- Py_RETURN_NONE;
-}
-
#ifdef _Py_TIER2
static PyObject *
{"get_co_localskinds", get_co_localskinds, METH_O, NULL},
{"get_code_var_counts", _PyCFunction_CAST(get_code_var_counts),
METH_VARARGS | METH_KEYWORDS, NULL},
- {"verify_stateless_code", _PyCFunction_CAST(verify_stateless_code),
- METH_VARARGS | METH_KEYWORDS, NULL},
#ifdef _Py_TIER2
{"add_executor_dependency", add_executor_dependency, METH_VARARGS, NULL},
{"invalidate_executors", invalidate_executors, METH_O, NULL},
}
-int
-_PyCode_CheckNoInternalState(PyCodeObject *co, const char **p_errmsg)
-{
- const char *errmsg = NULL;
- if (_PyCode_HAS_EXECUTORS(co) || _PyCode_HAS_INSTRUMENTATION(co)) {
- errmsg = "only basic code objects are supported";
- }
- else if (co->_co_monitoring != NULL) {
- errmsg = "only basic code objects are supported";
- }
- else if (co->co_extra != NULL) {
- errmsg = "only basic code objects are supported";
- }
-
- if (errmsg != NULL) {
- if (p_errmsg != NULL) {
- *p_errmsg = errmsg;
- }
- return 0;
- }
- return 1;
-}
-
-int
-_PyCode_CheckNoExternalState(PyCodeObject *co, _PyCode_var_counts_t *counts,
- const char **p_errmsg)
-{
- const char *errmsg = NULL;
- assert(counts->locals.hidden.total == 0);
- if (counts->numfree > 0) { // It's a closure.
- errmsg = "closures not supported";
- }
- else if (counts->unbound.globals.numglobal > 0) {
- errmsg = "globals not supported";
- }
- else if (counts->unbound.globals.numbuiltin > 0
- && counts->unbound.globals.numunknown > 0)
- {
- errmsg = "globals not supported";
- }
- // Otherwise we don't check counts.unbound.globals.numunknown since we can't
- // distinguish beween globals and builtins here.
-
- if (errmsg != NULL) {
- if (p_errmsg != NULL) {
- *p_errmsg = errmsg;
- }
- return 0;
- }
- return 1;
-}
-
-int
-_PyCode_VerifyStateless(PyThreadState *tstate,
- PyCodeObject *co, PyObject *globalnames,
- PyObject *globalsns, PyObject *builtinsns)
-{
- const char *errmsg;
- _PyCode_var_counts_t counts = {0};
- _PyCode_GetVarCounts(co, &counts);
- if (_PyCode_SetUnboundVarCounts(
- tstate, co, &counts, globalnames, NULL,
- globalsns, builtinsns) < 0)
- {
- return -1;
- }
- // We may consider relaxing the internal state constraints
- // if it becomes a problem.
- if (!_PyCode_CheckNoInternalState(co, &errmsg)) {
- _PyErr_SetString(tstate, PyExc_ValueError, errmsg);
- return -1;
- }
- if (builtinsns != NULL) {
- // Make sure the next check will fail for globals,
- // even if there aren't any builtins.
- counts.unbound.globals.numbuiltin += 1;
- }
- if (!_PyCode_CheckNoExternalState(co, &counts, &errmsg)) {
- _PyErr_SetString(tstate, PyExc_ValueError, errmsg);
- return -1;
- }
- // Note that we don't check co->co_flags & CO_NESTED for anything here.
- return 0;
-}
-
-
-int
-_PyCode_CheckPureFunction(PyCodeObject *co, const char **p_errmsg)
-{
- const char *errmsg = NULL;
- if (co->co_flags & CO_GENERATOR) {
- errmsg = "generators not supported";
- }
- else if (co->co_flags & CO_COROUTINE) {
- errmsg = "coroutines not supported";
- }
- else if (co->co_flags & CO_ITERABLE_COROUTINE) {
- errmsg = "coroutines not supported";
- }
- else if (co->co_flags & CO_ASYNC_GENERATOR) {
- errmsg = "generators not supported";
- }
-
- if (errmsg != NULL) {
- if (p_errmsg != NULL) {
- *p_errmsg = errmsg;
- }
- return 0;
- }
- return 1;
-}
-
/* Here "value" means a non-None value, since a bare return is identical
* to returning None explicitly. Likewise a missing return statement
* at the end of the function is turned into "return None". */
static int
code_returns_only_none(PyCodeObject *co)
{
- if (!_PyCode_CheckPureFunction(co, NULL)) {
- return 0;
- }
- int len = (int)Py_SIZE(co);
- assert(len > 0);
-
- // The last instruction either returns or raises. We can take advantage
- // of that for a quick exit.
- _Py_CODEUNIT final = _Py_GetBaseCodeUnit(co, len-1);
-
// Look up None in co_consts.
Py_ssize_t nconsts = PyTuple_Size(co->co_consts);
int none_index = 0;
}
if (none_index == nconsts) {
// None wasn't there, which means there was no implicit return,
- // "return", or "return None".
-
- // That means there must be
- // an explicit return (non-None), or it only raises.
- if (IS_RETURN_OPCODE(final.op.code)) {
- // It was an explicit return (non-None).
- return 0;
- }
- // It must end with a raise then. We still have to walk the
- // bytecode to see if there's any explicit return (non-None).
- assert(IS_RAISE_OPCODE(final.op.code));
- for (int i = 0; i < len; i += _PyInstruction_GetLength(co, i)) {
- _Py_CODEUNIT inst = _Py_GetBaseCodeUnit(co, i);
- if (IS_RETURN_OPCODE(inst.op.code)) {
- // We alraedy know it isn't returning None.
- return 0;
- }
- }
- // It must only raise.
+ // "return", or "return None". That means there must be
+ // an explicit return (non-None).
+ return 0;
}
- else {
- // Walk the bytecode, looking for RETURN_VALUE.
- for (int i = 0; i < len; i += _PyInstruction_GetLength(co, i)) {
- _Py_CODEUNIT inst = _Py_GetBaseCodeUnit(co, i);
- if (IS_RETURN_OPCODE(inst.op.code)) {
- assert(i != 0);
- // Ignore it if it returns None.
- _Py_CODEUNIT prev = _Py_GetBaseCodeUnit(co, i-1);
- if (prev.op.code == LOAD_CONST) {
- // We don't worry about EXTENDED_ARG for now.
- if (prev.op.arg == none_index) {
- continue;
- }
+
+ // Walk the bytecode, looking for RETURN_VALUE.
+ Py_ssize_t len = Py_SIZE(co);
+ for (int i = 0; i < len; i += _PyInstruction_GetLength(co, i)) {
+ _Py_CODEUNIT inst = _Py_GetBaseCodeUnit(co, i);
+ if (IS_RETURN_OPCODE(inst.op.code)) {
+ assert(i != 0);
+ // Ignore it if it returns None.
+ _Py_CODEUNIT prev = _Py_GetBaseCodeUnit(co, i-1);
+ if (prev.op.code == LOAD_CONST) {
+ // We don't worry about EXTENDED_ARG for now.
+ if (prev.op.arg == none_index) {
+ continue;
}
- return 0;
}
+ return 0;
}
}
return 1;
/* Function object implementation */
#include "Python.h"
-#include "pycore_code.h" // _PyCode_VerifyStateless()
#include "pycore_dict.h" // _Py_INCREF_DICT()
#include "pycore_function.h" // _PyFunction_Vectorcall
#include "pycore_long.h" // _PyLong_GetOne()
#include "pycore_modsupport.h" // _PyArg_NoKeywords()
#include "pycore_object.h" // _PyObject_GC_UNTRACK()
#include "pycore_pyerrors.h" // _PyErr_Occurred()
-#include "pycore_setobject.h" // _PySet_NextEntry()
#include "pycore_stats.h"
};
-int
-_PyFunction_VerifyStateless(PyThreadState *tstate, PyObject *func)
-{
- assert(!PyErr_Occurred());
- assert(PyFunction_Check(func));
-
- // Check the globals.
- PyObject *globalsns = PyFunction_GET_GLOBALS(func);
- if (globalsns != NULL && !PyDict_Check(globalsns)) {
- _PyErr_Format(tstate, PyExc_TypeError,
- "unsupported globals %R", globalsns);
- return -1;
- }
- // Check the builtins.
- PyObject *builtinsns = PyFunction_GET_BUILTINS(func);
- if (builtinsns != NULL && !PyDict_Check(builtinsns)) {
- _PyErr_Format(tstate, PyExc_TypeError,
- "unsupported builtins %R", builtinsns);
- return -1;
- }
- // Disallow __defaults__.
- PyObject *defaults = PyFunction_GET_DEFAULTS(func);
- if (defaults != NULL && defaults != Py_None && PyDict_Size(defaults) > 0)
- {
- _PyErr_SetString(tstate, PyExc_ValueError, "defaults not supported");
- return -1;
- }
- // Disallow __kwdefaults__.
- PyObject *kwdefaults = PyFunction_GET_KW_DEFAULTS(func);
- if (kwdefaults != NULL && kwdefaults != Py_None
- && PyDict_Size(kwdefaults) > 0)
- {
- _PyErr_SetString(tstate, PyExc_ValueError,
- "keyword defaults not supported");
- return -1;
- }
- // Disallow __closure__.
- PyObject *closure = PyFunction_GET_CLOSURE(func);
- if (closure != NULL && closure != Py_None && PyTuple_GET_SIZE(closure) > 0)
- {
- _PyErr_SetString(tstate, PyExc_ValueError, "closures not supported");
- return -1;
- }
- // Check the code.
- PyCodeObject *co = (PyCodeObject *)PyFunction_GET_CODE(func);
- if (_PyCode_VerifyStateless(tstate, co, NULL, globalsns, builtinsns) < 0) {
- return -1;
- }
- return 0;
-}
-
-
static int
functools_copy_attr(PyObject *wrapper, PyObject *wrapped, PyObject *name)
{