Mercurial > cpython-lru_cache-weakref
diff Python/ceval.c @ 64620:25cc226dc9bd
#4617: Previously it was illegal to delete a name from the local
namespace if it occurs as a free variable in a nested block. This limitation
of the compiler has been lifted, and a new opcode introduced (DELETE_DEREF).
This sample was valid in 2.6, but fails to compile in 3.x without this change::
>>> def f():
... def print_error():
... print(e)
... try:
... something
... except Exception as e:
... print_error()
... # implicit "del e" here
This sample has always been invalid in Python, and now works::
>>> def outer(x):
... def inner():
... return x
... inner()
... del x
There is no need to bump the PYC magic number: the new opcode is used
for code that did not compile before.
| author | Amaury Forgeot d'Arc <amauryfa@gmail.com> |
|---|---|
| date | Fri, 10 Sep 2010 21:39:53 +0000 |
| parents | 725231211273 |
| children | 9265752a1c83 |
line wrap: on
line diff
--- a/Python/ceval.c Fri Sep 10 20:43:53 2010 +0000 +++ b/Python/ceval.c Fri Sep 10 21:39:53 2010 +0000 @@ -135,6 +135,7 @@ static PyObject * import_from(PyObject *, PyObject *); static int import_all_from(PyObject *, PyObject *); static void format_exc_check_arg(PyObject *, const char *, PyObject *); +static void format_exc_unbound(PyCodeObject *co, int oparg); static PyObject * unicode_concatenate(PyObject *, PyObject *, PyFrameObject *, unsigned char *); static PyObject * special_lookup(PyObject *, char *, PyObject **); @@ -2143,6 +2144,16 @@ ); break; + TARGET(DELETE_DEREF) + x = freevars[oparg]; + if (PyCell_GET(x) != NULL) { + PyCell_Set(x, NULL); + continue; + } + err = -1; + format_exc_unbound(co, oparg); + break; + TARGET(LOAD_CLOSURE) x = freevars[oparg]; Py_INCREF(x); @@ -2158,22 +2169,7 @@ DISPATCH(); } err = -1; - /* Don't stomp existing exception */ - if (PyErr_Occurred()) - break; - if (oparg < PyTuple_GET_SIZE(co->co_cellvars)) { - v = PyTuple_GET_ITEM(co->co_cellvars, - oparg); - format_exc_check_arg( - PyExc_UnboundLocalError, - UNBOUNDLOCAL_ERROR_MSG, - v); - } else { - v = PyTuple_GET_ITEM(co->co_freevars, oparg - - PyTuple_GET_SIZE(co->co_cellvars)); - format_exc_check_arg(PyExc_NameError, - UNBOUNDFREE_ERROR_MSG, v); - } + format_exc_unbound(co, oparg); break; TARGET(STORE_DEREF) @@ -4352,6 +4348,28 @@ PyErr_Format(exc, format_str, obj_str); } +static void +format_exc_unbound(PyCodeObject *co, int oparg) +{ + PyObject *name; + /* Don't stomp existing exception */ + if (PyErr_Occurred()) + return; + if (oparg < PyTuple_GET_SIZE(co->co_cellvars)) { + name = PyTuple_GET_ITEM(co->co_cellvars, + oparg); + format_exc_check_arg( + PyExc_UnboundLocalError, + UNBOUNDLOCAL_ERROR_MSG, + name); + } else { + name = PyTuple_GET_ITEM(co->co_freevars, oparg - + PyTuple_GET_SIZE(co->co_cellvars)); + format_exc_check_arg(PyExc_NameError, + UNBOUNDFREE_ERROR_MSG, name); + } +} + static PyObject * unicode_concatenate(PyObject *v, PyObject *w, PyFrameObject *f, unsigned char *next_instr)