Revert "Fix Literal strings containing pipe characters" (#17638)

Reverts #17148

mypy/fastparse.py

@@ -331,7 +331,14 @@ def parse_type_string(
     """
     try:
         _, node = parse_type_comment(f"({expr_string})", line=line, column=column, errors=None)
-        return RawExpressionType(expr_string, expr_fallback_name, line, column, node=node)
+        if isinstance(node, UnboundType) and node.original_str_expr is None:
+            node.original_str_expr = expr_string
+            node.original_str_fallback = expr_fallback_name
+            return node
+        elif isinstance(node, UnionType):
+            return node
+        else:
+            return RawExpressionType(expr_string, expr_fallback_name, line, column)
     except (SyntaxError, ValueError):
         # Note: the parser will raise a `ValueError` instead of a SyntaxError if
         # the string happens to contain things like \x00.
@@ -1057,8 +1064,6 @@ def set_type_optional(self, type: Type | None, initializer: Expression | None) -
             return
         # Indicate that type should be wrapped in an Optional if arg is initialized to None.
         optional = isinstance(initializer, NameExpr) and initializer.name == "None"
-        if isinstance(type, RawExpressionType) and type.node is not None:
-            type = type.node
         if isinstance(type, UnboundType):
             type.optional = optional
 

mypy/semanal.py

@@ -3437,10 +3437,10 @@ def analyze_typeddict_assign(self, s: AssignmentStmt) -> bool:
     def analyze_lvalues(self, s: AssignmentStmt) -> None:
         # We cannot use s.type, because analyze_simple_literal_type() will set it.
         explicit = s.unanalyzed_type is not None
-        final_type = self.unwrap_final_type(s.unanalyzed_type)
-        if final_type is not None:
+        if self.is_final_type(s.unanalyzed_type):
             # We need to exclude bare Final.
-            if not final_type.args:
+            assert isinstance(s.unanalyzed_type, UnboundType)
+            if not s.unanalyzed_type.args:
                 explicit = False
 
         if s.rvalue:
@@ -3506,19 +3506,19 @@ def unwrap_final(self, s: AssignmentStmt) -> bool:
 
         Returns True if Final[...] was present.
         """
-        final_type = self.unwrap_final_type(s.unanalyzed_type)
-        if final_type is None:
+        if not s.unanalyzed_type or not self.is_final_type(s.unanalyzed_type):
             return False
-        if len(final_type.args) > 1:
-            self.fail("Final[...] takes at most one type argument", final_type)
+        assert isinstance(s.unanalyzed_type, UnboundType)
+        if len(s.unanalyzed_type.args) > 1:
+            self.fail("Final[...] takes at most one type argument", s.unanalyzed_type)
         invalid_bare_final = False
-        if not final_type.args:
+        if not s.unanalyzed_type.args:
             s.type = None
             if isinstance(s.rvalue, TempNode) and s.rvalue.no_rhs:
                 invalid_bare_final = True
                 self.fail("Type in Final[...] can only be omitted if there is an initializer", s)
         else:
-            s.type = final_type.args[0]
+            s.type = s.unanalyzed_type.args[0]
 
         if s.type is not None and self.is_classvar(s.type):
             self.fail("Variable should not be annotated with both ClassVar and Final", s)
@@ -4937,18 +4937,13 @@ def is_classvar(self, typ: Type) -> bool:
             return False
         return sym.node.fullname == "typing.ClassVar"
 
-    def unwrap_final_type(self, typ: Type | None) -> UnboundType | None:
-        if typ is None:
-            return None
-        typ = typ.resolve_string_annotation()
+    def is_final_type(self, typ: Type | None) -> bool:
         if not isinstance(typ, UnboundType):
-            return None
+            return False
         sym = self.lookup_qualified(typ.name, typ)
         if not sym or not sym.node:
-            return None
-        if sym.node.fullname in FINAL_TYPE_NAMES:
-            return typ
-        return None
+            return False
+        return sym.node.fullname in FINAL_TYPE_NAMES
 
     def fail_invalid_classvar(self, context: Context) -> None:
         self.fail(message_registry.CLASS_VAR_OUTSIDE_OF_CLASS, context)

mypy/server/astmerge.py

@@ -507,8 +507,7 @@ def visit_typeddict_type(self, typ: TypedDictType) -> None:
         typ.fallback.accept(self)
 
     def visit_raw_expression_type(self, t: RawExpressionType) -> None:
-        if t.node is not None:
-            t.node.accept(self)
+        pass
 
     def visit_literal_type(self, typ: LiteralType) -> None:
         typ.fallback.accept(self)

mypy/stubutil.py

@@ -17,16 +17,7 @@
 from mypy.modulefinder import ModuleNotFoundReason
 from mypy.moduleinspect import InspectError, ModuleInspect
 from mypy.stubdoc import ArgSig, FunctionSig
-from mypy.types import (
-    AnyType,
-    NoneType,
-    RawExpressionType,
-    Type,
-    TypeList,
-    TypeStrVisitor,
-    UnboundType,
-    UnionType,
-)
+from mypy.types import AnyType, NoneType, Type, TypeList, TypeStrVisitor, UnboundType, UnionType
 
 # Modules that may fail when imported, or that may have side effects (fully qualified).
 NOT_IMPORTABLE_MODULES = ()
@@ -302,11 +293,12 @@ def args_str(self, args: Iterable[Type]) -> str:
         The main difference from list_str is the preservation of quotes for string
         arguments
         """
+        types = ["builtins.bytes", "builtins.str"]
         res = []
         for arg in args:
             arg_str = arg.accept(self)
-            if isinstance(arg, RawExpressionType):
-                res.append(repr(arg.literal_value))
+            if isinstance(arg, UnboundType) and arg.original_str_fallback in types:
+                res.append(f"'{arg_str}'")
             else:
                 res.append(arg_str)
         return ", ".join(res)

mypy/type_visitor.py

@@ -382,8 +382,6 @@ def visit_typeddict_type(self, t: TypedDictType) -> T:
         return self.query_types(t.items.values())
 
     def visit_raw_expression_type(self, t: RawExpressionType) -> T:
-        if t.node is not None:
-            return t.node.accept(self)
         return self.strategy([])
 
     def visit_literal_type(self, t: LiteralType) -> T:
@@ -524,8 +522,6 @@ def visit_typeddict_type(self, t: TypedDictType) -> bool:
         return self.query_types(list(t.items.values()))
 
     def visit_raw_expression_type(self, t: RawExpressionType) -> bool:
-        if t.node is not None:
-            return t.node.accept(self)
         return self.default
 
     def visit_literal_type(self, t: LiteralType) -> bool:

mypy/typeanal.py

@@ -1112,7 +1112,6 @@ def visit_callable_type(
         return ret
 
     def anal_type_guard(self, t: Type) -> Type | None:
-        t = t.resolve_string_annotation()
         if isinstance(t, UnboundType):
             sym = self.lookup_qualified(t.name, t)
             if sym is not None and sym.node is not None:
@@ -1131,7 +1130,6 @@ def anal_type_guard_arg(self, t: UnboundType, fullname: str) -> Type | None:
         return None
 
     def anal_type_is(self, t: Type) -> Type | None:
-        t = t.resolve_string_annotation()
         if isinstance(t, UnboundType):
             sym = self.lookup_qualified(t.name, t)
             if sym is not None and sym.node is not None:
@@ -1149,7 +1147,6 @@ def anal_type_is_arg(self, t: UnboundType, fullname: str) -> Type | None:
 
     def anal_star_arg_type(self, t: Type, kind: ArgKind, nested: bool) -> Type:
         """Analyze signature argument type for *args and **kwargs argument."""
-        t = t.resolve_string_annotation()
         if isinstance(t, UnboundType) and t.name and "." in t.name and not t.args:
             components = t.name.split(".")
             tvar_name = ".".join(components[:-1])
@@ -1275,8 +1272,6 @@ def visit_raw_expression_type(self, t: RawExpressionType) -> Type:
         # make signatures like "foo(x: 20) -> None" legal, we can change
         # this method so it generates and returns an actual LiteralType
         # instead.
-        if t.node is not None:
-            return t.node.accept(self)
 
         if self.report_invalid_types:
             if t.base_type_name in ("builtins.int", "builtins.bool"):
@@ -1539,7 +1534,6 @@ def analyze_callable_args(
         invalid_unpacks: list[Type] = []
         second_unpack_last = False
         for i, arg in enumerate(arglist.items):
-            arg = arg.resolve_string_annotation()
             if isinstance(arg, CallableArgument):
                 args.append(arg.typ)
                 names.append(arg.name)
@@ -1620,6 +1614,18 @@ def analyze_literal_type(self, t: UnboundType) -> Type:
         return UnionType.make_union(output, line=t.line)
 
     def analyze_literal_param(self, idx: int, arg: Type, ctx: Context) -> list[Type] | None:
+        # This UnboundType was originally defined as a string.
+        if isinstance(arg, UnboundType) and arg.original_str_expr is not None:
+            assert arg.original_str_fallback is not None
+            return [
+                LiteralType(
+                    value=arg.original_str_expr,
+                    fallback=self.named_type(arg.original_str_fallback),
+                    line=arg.line,
+                    column=arg.column,
+                )
+            ]
+
         # If arg is an UnboundType that was *not* originally defined as
         # a string, try expanding it in case it's a type alias or something.
         if isinstance(arg, UnboundType):
@@ -2605,8 +2611,7 @@ def visit_typeddict_type(self, t: TypedDictType) -> None:
         self.process_types(list(t.items.values()))
 
     def visit_raw_expression_type(self, t: RawExpressionType) -> None:
-        if t.node is not None:
-            t.node.accept(self)
+        pass
 
     def visit_literal_type(self, t: LiteralType) -> None:
         pass