Prevent unknown names in annotations from being interpreted (and declared!) as builtins.

Closes #1887.

Cython/Compiler/ExprNodes.py

@@ -1362,18 +1362,17 @@ def _analyse_name_as_type(name, pos, env):
     type = PyrexTypes.parse_basic_type(name)
     if type is not None:
         return type
+    from .TreeFragment import TreeFragment
     with local_errors(ignore=True):
-        from .TreeFragment import TreeFragment
         pos = (pos[0], pos[1], pos[2]-7)
         try:
             declaration = TreeFragment(u"sizeof(%s)" % name, name=pos[0].filename, initial_pos=pos)
         except CompileError:
-            sizeof_node = None
+            pass
         else:
             sizeof_node = declaration.root.stats[0].expr
-            sizeof_node = sizeof_node.analyse_types(env)
-    if isinstance(sizeof_node, SizeofTypeNode):
-        return sizeof_node.arg_type
+            if isinstance(sizeof_node, SizeofTypeNode):
+                return sizeof_node.arg_type.analyse_types(env)
     return None
 
 

tests/run/annotation_typing.pyx

@@ -196,6 +196,25 @@ def call_exception_default(raise_exc=False):
     return exception_default(raise_exc)
 
 
+class EarlyClass(object):
+    """
+    >>> a = EarlyClass(1)
+    >>> a.string_forward_declaration()  # should probably raise an error at some point
+    1
+    >>> x = LateClass()
+    >>> a = EarlyClass(x)
+    >>> x2 = a.string_forward_declaration()
+    >>> assert x is x2, x2
+    """
+    def __init__(self, x):
+        self.x = x
+    def string_forward_declaration(self) -> 'LateClass':
+        return self.x
+
+class LateClass(object):
+    pass
+
+
 _WARNINGS = """
 8:32: Strings should no longer be used for type declarations. Use 'cython.int' etc. directly.
 8:47: Dicts should no longer be used as type annotations. Use 'cython.int' etc. directly.
@@ -203,6 +222,7 @@ _WARNINGS = """
 8:77: Dicts should no longer be used as type annotations. Use 'cython.int' etc. directly.
 8:85: Python type declaration in signature annotation does not refer to a Python type
 8:85: Strings should no longer be used for type declarations. Use 'cython.int' etc. directly.
+211:44: Unknown type declaration in annotation, ignoring
 # BUG:
 46:6: 'pytypes_cpdef' redeclared
 121:0: 'struct_io' redeclared