Also issue warnings if setattr is used in a class instead of an error

jedi/evaluate/analysis.py

@@ -82,6 +82,20 @@ def add(evaluator, name, jedi_obj, message=None, typ=Error, payload=None):
     evaluator.analysis.append(instance)
 
 
+def _check_for_setattr(instance):
+    """
+    Check if there's any setattr method inside an instance. If so, return True.
+    """
+    module = instance.get_parent_until()
+    try:
+        stmts = module.used_names['setattr']
+    except KeyError:
+        return False
+
+    return any(instance.start_pos < stmt.start_pos < instance.end_pos
+               for stmt in stmts)
+
+
 def add_attribute_error(evaluator, scope, name_part):
     message = ('AttributeError: %s has no attribute %s.' % (scope, name_part))
     from jedi.evaluate.representation import Instance
@@ -95,6 +109,7 @@ def add_attribute_error(evaluator, scope, name_part):
             try:
                 scope.get_subscope_by_name('__getattribute__')
             except KeyError:
+                if not _check_for_setattr(scope):
                     typ = Error
     else:
         typ = Error

jedi/evaluate/finder.py

@@ -115,7 +115,6 @@ class NameFinder(object):
             if result:
                 break
 
-        self._last_filter_name_scope = name_list_scope
         scope_txt = (self.scope if self.scope == name_list_scope
                      else '%s-%s' % (self.scope, name_list_scope))
         debug.dbg('finder.filter_name "%s" in (%s): %s@%s', self.name_str,

test/static_analysis/attribute_warnings.py

@@ -3,6 +3,10 @@ Jedi issues warnings for possible errors if ``__getattr__``,
 ``__getattribute__`` or ``setattr`` are used.
 """
 
+# -----------------
+# __getattr*__
+# -----------------
+
 
 class Cls():
     def __getattr__(self, name):
@@ -22,3 +26,21 @@ Inherited().upper
 
 #! 12 warning attribute-error
 Inherited().undefined
+
+# -----------------
+# setattr
+# -----------------
+
+
+class SetattrCls():
+    def __init__(self, dct):
+        # Jedi doesn't even try to understand such code
+        for k, v in dct:
+            setattr(self, k, v)
+
+        self.defined = 3
+
+c = SetattrCls({'a': 'b'})
+c.defined
+#! 2 warning attribute-error
+c.undefined