gh-85267: Improvements to inspect.signature __text_signature__ handling

Lib/inspect.py

@@ -2109,7 +2109,7 @@ def _signature_strip_non_python_syntax(signature):
  self_parameter = None
  last_positional_only = None
 
- lines = [l.encode('ascii') for l in signature.split('\n')]
+ lines = [l.encode('ascii') for l in signature.split('\n') if l]
  generator = iter(lines).__next__
  token_stream = tokenize.tokenize(generator)
 
@@ -2185,7 +2185,6 @@ def _signature_fromstr(cls, obj, s, skip_bound_arg=True):
 
  parameters = []
  empty = Parameter.empty
- invalid = object()
 
  module = None
  module_dict = {}
@@ -2209,11 +2208,11 @@ def wrap_value(s):
  try:
  value = eval(s, sys_module_dict)
  except NameError:
- raise RuntimeError()
+ raise ValueError
 
  if isinstance(value, (str, int, float, bytes, bool, type(None))):
  return ast.Constant(value)
- raise RuntimeError()
+ raise ValueError
 
  class RewriteSymbolics(ast.NodeTransformer):
  def visit_Attribute(self, node):
@@ -2233,19 +2232,27 @@ def visit_Name(self, node):
  raise ValueError()
  return wrap_value(node.id)
 
+ def visit_BinOp(self, node):
+ left = self.visit(node.left)
+ right = self.visit(node.right)
+ if not isinstance(left, ast.Constant) or not isinstance(right, ast.Constant):
+ raise ValueError
+ if isinstance(node.op, ast.Add):
+ return ast.Constant(left.value + right.value)
+ elif isinstance(node.op, ast.Sub):
+ return ast.Constant(left.value - right.value)
+ elif isinstance(node.op, ast.BitOr):
+ return ast.Constant(left.value | right.value)
+ raise ValueError
+
  def p(name_node, default_node, default=empty):
  name = parse_name(name_node)
- if name is invalid:
- return None
  if default_node and default_node is not _empty:
  try:
  default_node = RewriteSymbolics().visit(default_node)
- o = ast.literal_eval(default_node)
+ default = ast.literal_eval(default_node)
  except ValueError:
- o = invalid
- if o is invalid:
- return None
- default = o if o is not invalid else default
+ raise ValueError("{!r} builtin has invalid signature".format(obj)) from None
  parameters.append(Parameter(name, kind, default=default, annotation=empty))
 
  # non-keyword-only parameters

Lib/test/test_inspect.py

@@ -2474,7 +2474,7 @@ def p(name): return signature.parameters[name].default
  self.assertEqual(p('f'), False)
  self.assertEqual(p('local'), 3)
  self.assertEqual(p('sys'), sys.maxsize)
- self.assertNotIn('exp', signature.parameters)
+ self.assertEqual(p('exp'), sys.maxsize - 1)
 
  test_callable(object)
 
@@ -4235,10 +4235,30 @@ def func(*args, **kwargs):
  sig = inspect.signature(func)
  self.assertIsNotNone(sig)
  self.assertEqual(str(sig), '(self, /, a, b=1, *args, c, d=2, **kwargs)')
+
  func.__text_signature__ = '($self, a, b=1, /, *args, c, d=2, **kwargs)'
  sig = inspect.signature(func)
  self.assertEqual(str(sig), '(self, a, b=1, /, *args, c, d=2, **kwargs)')
 
+ func.__text_signature__ = '(self, a=1+2, b=4-3, c=1 | 4 | 16)'
+ sig = inspect.signature(func)
+ self.assertEqual(str(sig), '(self, a=3, b=1, c=21)')
+
+ func.__text_signature__ = '(self, a=1,\nb=2,\n\n\n c=3)'
+ sig = inspect.signature(func)
+ self.assertEqual(str(sig), '(self, a=1, b=2, c=3)')
+
+ func.__text_signature__ = '(self, x=does_not_exist)'
+ with self.assertRaises(ValueError):
+ inspect.signature(func)
+ func.__text_signature__ = '(self, x=sys, y=inspect)'
+ with self.assertRaises(ValueError):
+ inspect.signature(func)
+ func.__text_signature__ = '(self, 123)'
+ with self.assertRaises(ValueError):
+ inspect.signature(func)
+
+
  def test_base_class_have_text_signature(self):
  # see issue 43118
  from test.ann_module7 import BufferedReader