mirrors
/
cpython
mirror of https://github.com/python/cpython.git
2
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

gh-104602: ensure all cellvars are known up front (#104603) 

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
This commit is contained in:
Carl Meyer 2023-05-18 18:07:35 -06:00 committed by GitHub
parent 3fadd7d585
commit 86e6f16ccb
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 50 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
Include/internal/pycore_symtable.h
View File

@ -120,14 +120,15 @@ extern PyObject* _Py_Mangle(PyObject *p, PyObject *name);
#define DEF_ANNOT 2<<7 /* this name is annotated */
#define DEF_COMP_ITER 2<<8 /* this name is a comprehension iteration variable */
#define DEF_TYPE_PARAM 2<<9 /* this name is a type parameter */
#define DEF_COMP_CELL 2<<10 /* this name is a cell in an inlined comprehension */
#define DEF_BOUND (DEF_LOCAL | DEF_PARAM | DEF_IMPORT)
/* GLOBAL_EXPLICIT and GLOBAL_IMPLICIT are used internally by the symbol
table. GLOBAL is returned from PyST_GetScope() for either of them.
It is stored in ste_symbols at bits 12-15.
It is stored in ste_symbols at bits 13-16.
*/
#define SCOPE_OFFSET 11
#define SCOPE_OFFSET 12
#define SCOPE_MASK (DEF_GLOBAL | DEF_LOCAL | DEF_PARAM | DEF_NONLOCAL)
#define LOCAL 1

26
Lib/test/test_listcomps.py
View File

@ -381,6 +381,32 @@ def f():
with self.assertRaises(UnboundLocalError):
f()
def test_global_outside_cellvar_inside_plus_freevar(self):
code = """
a = 1
def f():
func, = [(lambda: b) for b in [a]]
return b, func()
x = f()
"""
self._check_in_scopes(
code, {"x": (2, 1)}, ns={"b": 2}, scopes=["function", "module"])
# inside a class, the `a = 1` assignment is not visible
self._check_in_scopes(code, raises=NameError, scopes=["class"])
def test_cell_in_nested_comprehension(self):
code = """
a = 1
def f():
(func, inner_b), = [[lambda: b for b in c] + [b] for c in [[a]]]
return b, inner_b, func()
x = f()
"""
self._check_in_scopes(
code, {"x": (2, 2, 1)}, ns={"b": 2}, scopes=["function", "module"])
# inside a class, the `a = 1` assignment is not visible
self._check_in_scopes(code, raises=NameError, scopes=["class"])
def test_name_error_in_class_scope(self):
code = """
y = 1

2
Python/compile.c
View File

@ -1252,7 +1252,7 @@ compiler_enter_scope(struct compiler *c, identifier name,
}
u->u_metadata.u_name = Py_NewRef(name);
u->u_metadata.u_varnames = list2dict(u->u_ste->ste_varnames);
u->u_metadata.u_cellvars = dictbytype(u->u_ste->ste_symbols, CELL, 0, 0);
u->u_metadata.u_cellvars = dictbytype(u->u_ste->ste_symbols, CELL, DEF_COMP_CELL, 0);
if (!u->u_metadata.u_varnames || !u->u_metadata.u_cellvars) {
compiler_unit_free(u);
return ERROR;

39
Python/symtable.c
View File

@ -632,7 +632,7 @@ is_free_in_any_child(PySTEntryObject *entry, PyObject *key)
static int
inline_comprehension(PySTEntryObject *ste, PySTEntryObject *comp,
PyObject *scopes, PyObject *comp_free,
PyObject *promote_to_cell)
PyObject *inlined_cells)
{
PyObject *k, *v;
Py_ssize_t pos = 0;
@ -645,6 +645,11 @@ inline_comprehension(PySTEntryObject *ste, PySTEntryObject *comp,
}
int scope = (comp_flags >> SCOPE_OFFSET) & SCOPE_MASK;
int only_flags = comp_flags & ((1 << SCOPE_OFFSET) - 1);
if (scope == CELL || only_flags & DEF_COMP_CELL) {
if (PySet_Add(inlined_cells, k) < 0) {
return 0;
}
}
PyObject *existing = PyDict_GetItemWithError(ste->ste_symbols, k);
if (existing == NULL && PyErr_Occurred()) {
return 0;
@ -665,14 +670,6 @@ inline_comprehension(PySTEntryObject *ste, PySTEntryObject *comp,
}
else {
if (PyLong_AsLong(existing) & DEF_BOUND) {
// cell vars in comprehension that are locals in outer scope
// must be promoted to cell so u_cellvars isn't wrong
if (scope == CELL && _PyST_IsFunctionLike(ste)) {
if (PySet_Add(promote_to_cell, k) < 0) {
return 0;
}
}
// free vars in comprehension that are locals in outer scope can
// now simply be locals, unless they are free in comp children,
// or if the outer scope is a class block
@ -698,7 +695,7 @@ inline_comprehension(PySTEntryObject *ste, PySTEntryObject *comp,
*/
static int
analyze_cells(PyObject *scopes, PyObject *free, PyObject *promote_to_cell)
analyze_cells(PyObject *scopes, PyObject *free, PyObject *inlined_cells)
{
PyObject *name, *v, *v_cell;
int success = 0;
@ -713,7 +710,7 @@ analyze_cells(PyObject *scopes, PyObject *free, PyObject *promote_to_cell)
scope = PyLong_AS_LONG(v);
if (scope != LOCAL)
continue;
if (!PySet_Contains(free, name) && !PySet_Contains(promote_to_cell, name))
if (!PySet_Contains(free, name) && !PySet_Contains(inlined_cells, name))
continue;
/* Replace LOCAL with CELL for this name, and remove
from free. It is safe to replace the value of name
@ -753,7 +750,8 @@ drop_class_free(PySTEntryObject *ste, PyObject *free)
*/
static int
update_symbols(PyObject *symbols, PyObject *scopes,
PyObject *bound, PyObject *free, int classflag)
PyObject *bound, PyObject *free,
PyObject *inlined_cells, int classflag)
{
PyObject *name = NULL, *itr = NULL;
PyObject *v = NULL, *v_scope = NULL, *v_new = NULL, *v_free = NULL;
@ -764,6 +762,9 @@ update_symbols(PyObject *symbols, PyObject *scopes,
long scope, flags;
assert(PyLong_Check(v));
flags = PyLong_AS_LONG(v);
if (PySet_Contains(inlined_cells, name)) {
flags |= DEF_COMP_CELL;
}
v_scope = PyDict_GetItemWithError(scopes, name);
assert(v_scope && PyLong_Check(v_scope));
scope = PyLong_AS_LONG(v_scope);
@ -870,7 +871,7 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
PySTEntryObject *class_entry)
{
PyObject *name, *v, *local = NULL, *scopes = NULL, *newbound = NULL;
PyObject *newglobal = NULL, *newfree = NULL, *promote_to_cell = NULL;
PyObject *newglobal = NULL, *newfree = NULL, *inlined_cells = NULL;
PyObject *temp;
int success = 0;
Py_ssize_t i, pos = 0;
@ -902,8 +903,8 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
newbound = PySet_New(NULL);
if (!newbound)
goto error;
promote_to_cell = PySet_New(NULL);
if (!promote_to_cell)
inlined_cells = PySet_New(NULL);
if (!inlined_cells)
goto error;
/* Class namespace has no effect on names visible in
@ -997,7 +998,7 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
goto error;
}
if (inline_comp) {
if (!inline_comprehension(ste, entry, scopes, child_free, promote_to_cell)) {
if (!inline_comprehension(ste, entry, scopes, child_free, inlined_cells)) {
Py_DECREF(child_free);
goto error;
}
@ -1028,12 +1029,12 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
}
/* Check if any local variables must be converted to cell variables */
if (_PyST_IsFunctionLike(ste) && !analyze_cells(scopes, newfree, promote_to_cell))
if (_PyST_IsFunctionLike(ste) && !analyze_cells(scopes, newfree, inlined_cells))
goto error;
else if (ste->ste_type == ClassBlock && !drop_class_free(ste, newfree))
goto error;
/* Records the results of the analysis in the symbol table entry */
if (!update_symbols(ste->ste_symbols, scopes, bound, newfree,
if (!update_symbols(ste->ste_symbols, scopes, bound, newfree, inlined_cells,
ste->ste_type == ClassBlock))
goto error;
@ -1048,7 +1049,7 @@ analyze_block(PySTEntryObject *ste, PyObject *bound, PyObject *free,
Py_XDECREF(newbound);
Py_XDECREF(newglobal);
Py_XDECREF(newfree);
Py_XDECREF(promote_to_cell);
Py_XDECREF(inlined_cells);
if (!success)
assert(PyErr_Occurred());
return success;