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gh-121914: Change the names of the symbol tables for lambda and genexpr #135288

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gh-121914: Change the names of the symbol tables for lambda and genexpr #135288

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5 changes: 0 additions & 5 deletions Include/internal/pycore_global_objects_fini_generated.h
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5 changes: 0 additions & 5 deletions Include/internal/pycore_global_strings.h
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Original file line number Diff line number Diff line change
Expand Up @@ -395,7 +395,6 @@ struct _Py_global_strings {
STRUCT_FOR_ID(deterministic)
STRUCT_FOR_ID(device)
STRUCT_FOR_ID(dict)
STRUCT_FOR_ID(dictcomp)
STRUCT_FOR_ID(difference_update)
STRUCT_FOR_ID(digest)
STRUCT_FOR_ID(digest_size)
Expand Down Expand Up @@ -470,7 +469,6 @@ struct _Py_global_strings {
STRUCT_FOR_ID(func)
STRUCT_FOR_ID(future)
STRUCT_FOR_ID(generation)
STRUCT_FOR_ID(genexpr)
STRUCT_FOR_ID(get)
STRUCT_FOR_ID(get_debug)
STRUCT_FOR_ID(get_event_loop)
Expand Down Expand Up @@ -546,7 +544,6 @@ struct _Py_global_strings {
STRUCT_FOR_ID(kw2)
STRUCT_FOR_ID(kwdefaults)
STRUCT_FOR_ID(label)
STRUCT_FOR_ID(lambda)
STRUCT_FOR_ID(last)
STRUCT_FOR_ID(last_exc)
STRUCT_FOR_ID(last_node)
Expand All @@ -562,7 +559,6 @@ struct _Py_global_strings {
STRUCT_FOR_ID(line)
STRUCT_FOR_ID(line_buffering)
STRUCT_FOR_ID(lineno)
STRUCT_FOR_ID(listcomp)
STRUCT_FOR_ID(little)
STRUCT_FOR_ID(lo)
STRUCT_FOR_ID(locale)
Expand Down Expand Up @@ -708,7 +704,6 @@ struct _Py_global_strings {
STRUCT_FOR_ID(server_hostname)
STRUCT_FOR_ID(server_side)
STRUCT_FOR_ID(session)
STRUCT_FOR_ID(setcomp)
STRUCT_FOR_ID(setpgroup)
STRUCT_FOR_ID(setsid)
STRUCT_FOR_ID(setsigdef)
Expand Down
5 changes: 0 additions & 5 deletions Include/internal/pycore_runtime_init_generated.h
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20 changes: 0 additions & 20 deletions Include/internal/pycore_unicodeobject_generated.h
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12 changes: 0 additions & 12 deletions Lib/symtable.py
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Original file line number Diff line number Diff line change
Expand Up @@ -255,25 +255,13 @@ def is_local_symbol(ident):
if is_local_symbol(st.name):
match st.type:
case _symtable.TYPE_FUNCTION:
# generators are of type TYPE_FUNCTION with a ".0"
# parameter as a first parameter (which makes them
# distinguishable from a function named 'genexpr')
if st.name == 'genexpr' and '.0' in st.varnames:
continue
Comment on lines -258 to -262
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Thank you. This hack was ugly.

d[st.name] = 1
case _symtable.TYPE_TYPE_PARAMETERS:
# Get the function-def block in the annotation
# scope 'st' with the same identifier, if any.
scope_name = st.name
for c in st.children:
if c.name == scope_name and c.type == _symtable.TYPE_FUNCTION:
# A generic generator of type TYPE_FUNCTION
# cannot be a direct child of 'st' (but it
# can be a descendant), e.g.:
#
# class A:
# type genexpr[genexpr] = (x for x in [])
assert scope_name != 'genexpr' or '.0' not in c.varnames
d[scope_name] = 1
break
self.__methods = tuple(d)
Expand Down
52 changes: 52 additions & 0 deletions Lib/test/test_symtable.py
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Original file line number Diff line number Diff line change
Expand Up @@ -527,6 +527,58 @@ def test_symtable_entry_repr(self):
expected = f"<symtable entry top({self.top.get_id()}), line {self.top.get_lineno()}>"
self.assertEqual(repr(self.top._table), expected)

def test_lambda(self):
st = symtable.symtable("lambda x: x", "?", "exec")
self.assertEqual(len(st.get_children()), 1)
st = st.get_children()[0]
self.assertIs(st.get_type(), symtable.SymbolTableType.FUNCTION)
self.assertEqual(st.get_name(), "<lambda>")
self.assertFalse(st.is_nested())
self.assertEqual(sorted(st.get_identifiers()), ["x"])
self.assertEqual(st.get_children(), [])

def test_nested_lambda(self):
st = symtable.symtable("lambda x: lambda y=x: y", "?", "exec")
self.assertEqual(len(st.get_children()), 1)
st = st.get_children()[0]
self.assertIs(st.get_type(), symtable.SymbolTableType.FUNCTION)
self.assertEqual(st.get_name(), "<lambda>")
self.assertFalse(st.is_nested())
self.assertEqual(sorted(st.get_identifiers()), ["x"])
self.assertEqual(len(st.get_children()), 1)
st = st.get_children()[0]
self.assertIs(st.get_type(), symtable.SymbolTableType.FUNCTION)
self.assertEqual(st.get_name(), "<lambda>")
self.assertTrue(st.is_nested())
self.assertEqual(sorted(st.get_identifiers()), ["y"])
self.assertEqual(st.get_children(), [])

def test_genexpr(self):
st = symtable.symtable("(x for x in a)", "?", "exec")
self.assertEqual(len(st.get_children()), 1)
st = st.get_children()[0]
self.assertIs(st.get_type(), symtable.SymbolTableType.FUNCTION)
self.assertEqual(st.get_name(), "<genexpr>")
self.assertFalse(st.is_nested())
self.assertEqual(sorted(st.get_identifiers()), [".0", "x"])
self.assertEqual(st.get_children(), [])

def test_nested_genexpr(self):
st = symtable.symtable("((y for y in x) for x in a)", "?", "exec")
self.assertEqual(len(st.get_children()), 1)
st = st.get_children()[0]
self.assertIs(st.get_type(), symtable.SymbolTableType.FUNCTION)
self.assertEqual(st.get_name(), "<genexpr>")
self.assertFalse(st.is_nested())
self.assertEqual(sorted(st.get_identifiers()), [".0", "x"])
self.assertEqual(len(st.get_children()), 1)
st = st.get_children()[0]
self.assertIs(st.get_type(), symtable.SymbolTableType.FUNCTION)
self.assertEqual(st.get_name(), "<genexpr>")
self.assertTrue(st.is_nested())
self.assertEqual(sorted(st.get_identifiers()), [".0", "y"])
self.assertEqual(st.get_children(), [])


class ComprehensionTests(unittest.TestCase):
def get_identifiers_recursive(self, st, res):
Expand Down
3 changes: 3 additions & 0 deletions Misc/NEWS.d/next/Library/2025-06-09-10-16-55.gh-issue-121914.G6Avkq.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Changed the names of the symbol tables for lambda expressions and generator
expressions to "<lambda>" and "<genexpr>" respectively to avoid conflicts
with user-defined names.
10 changes: 5 additions & 5 deletions Python/symtable.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2413,7 +2413,7 @@ symtable_visit_expr(struct symtable *st, expr_ty e)
VISIT_SEQ(st, expr, e->v.Lambda.args->defaults);
if (e->v.Lambda.args->kw_defaults)
VISIT_SEQ_WITH_NULL(st, expr, e->v.Lambda.args->kw_defaults);
if (!symtable_enter_block(st, &_Py_ID(lambda),
if (!symtable_enter_block(st, &_Py_STR(anon_lambda),
FunctionBlock, (void *)e, LOCATION(e))) {
return 0;
}
Expand Down Expand Up @@ -3055,31 +3055,31 @@ symtable_handle_comprehension(struct symtable *st, expr_ty e,
static int
symtable_visit_genexp(struct symtable *st, expr_ty e)
{
return symtable_handle_comprehension(st, e, &_Py_ID(genexpr),
return symtable_handle_comprehension(st, e, &_Py_STR(anon_genexpr),
e->v.GeneratorExp.generators,
e->v.GeneratorExp.elt, NULL);
}

static int
symtable_visit_listcomp(struct symtable *st, expr_ty e)
{
return symtable_handle_comprehension(st, e, &_Py_ID(listcomp),
return symtable_handle_comprehension(st, e, &_Py_STR(anon_listcomp),
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Should there be tests for this one too?

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I cannot write them.

e->v.ListComp.generators,
e->v.ListComp.elt, NULL);
}

static int
symtable_visit_setcomp(struct symtable *st, expr_ty e)
{
return symtable_handle_comprehension(st, e, &_Py_ID(setcomp),
return symtable_handle_comprehension(st, e, &_Py_STR(anon_setcomp),
e->v.SetComp.generators,
e->v.SetComp.elt, NULL);
}

static int
symtable_visit_dictcomp(struct symtable *st, expr_ty e)
{
return symtable_handle_comprehension(st, e, &_Py_ID(dictcomp),
return symtable_handle_comprehension(st, e, &_Py_STR(anon_dictcomp),
e->v.DictComp.generators,
e->v.DictComp.key,
e->v.DictComp.value);
Expand Down
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