Mark more things as literals

mypy/checker.py

@@ -6543,10 +6543,6 @@ def comparison_type_narrowing_helper(self, node: ComparisonExpr) -> tuple[TypeMa
 
             if (
                 literal(expr) == LITERAL_TYPE
-                and not is_literal_none(expr)
-                and not is_literal_not_implemented(expr)
-                and not is_false_literal(expr)
-                and not is_true_literal(expr)
                 and not self.is_literal_enum(expr)
                 and not (
                     isinstance(p_expr := get_proper_type(expr_type), CallableType)

mypy/literals.py

@@ -35,6 +35,7 @@
     OpExpr,
     ParamSpecExpr,
     PromoteExpr,
+    RefExpr,
     RevealExpr,
     SetComprehension,
     SetExpr,
@@ -44,6 +45,7 @@
     SuperExpr,
     TempNode,
     TupleExpr,
+    TypeAlias,
     TypeAliasExpr,
     TypeApplication,
     TypedDictExpr,
@@ -55,6 +57,7 @@
     YieldExpr,
     YieldFromExpr,
 )
+from mypy.types import is_named_instance
 from mypy.visitor import ExpressionVisitor
 
 # [Note Literals and literal_hash]
@@ -97,6 +100,9 @@
 
 
 Key: _TypeAlias = tuple[Any, ...]
+LITERAL_NAMES: Final = frozenset(
+    ("builtins.True", "builtins.False", "builtins.None", "builtins.NotImplemented")
+)
 
 
 def literal_hash(e: Expression) -> Key | None:
@@ -135,10 +141,23 @@ def literal(e: Expression) -> int:
         else:
             return LITERAL_NO
 
-    elif isinstance(e, NameExpr):
-        if isinstance(e.node, Var) and e.node.is_final and e.node.final_value is not None:
+    elif isinstance(e, RefExpr):
+        if (
+            isinstance(e, NameExpr)
+            and isinstance(e.node, Var)
+            and e.node.is_final
+            and e.node.final_value is not None
+        ):
             return LITERAL_YES
-        return LITERAL_TYPE
+
+        if e.fullname in LITERAL_NAMES:
+            return LITERAL_YES
+        elif isinstance(e.node, TypeAlias) and not e.node.python_3_12_type_alias:
+            if is_named_instance(e.node.target, LITERAL_NAMES):
+                return LITERAL_YES
+
+        if isinstance(e, NameExpr):
+            return LITERAL_TYPE
 
     if isinstance(e, (IntExpr, FloatExpr, ComplexExpr, StrExpr, BytesExpr)):
         return LITERAL_YES

mypy/types.py

@@ -4040,8 +4040,8 @@ def visit_type_alias_type(self, t: TypeAliasType, /) -> list[mypy.nodes.TypeAlia
         return res
 
 
-def is_named_instance(t: Type, fullnames: str | tuple[str, ...]) -> TypeGuard[Instance]:
-    if not isinstance(fullnames, tuple):
+def is_named_instance(t: Type, fullnames: str | Iterable[str]) -> TypeGuard[Instance]:
+    if isinstance(fullnames, str):
         fullnames = (fullnames,)
 
     t = get_proper_type(t)