Simplify recursion issues.

jedi/evaluate/__init__.py

@@ -108,7 +108,7 @@ class Evaluator(object):
         self.BUILTINS = compiled.get_special_object(self, 'BUILTINS')
 
     def reset_recursion_limitations(self):
-        self.recursion_detector = recursion.RecursionDetector(self)
+        self.recursion_detector = recursion.RecursionDetector()
         self.execution_recursion_detector = recursion.ExecutionRecursionDetector(self)
 
     def find_types(self, context, name_or_str, name_context, position=None,

jedi/evaluate/iterable.py

@@ -20,21 +20,22 @@ It is important to note that:
 1. Array modfications work only in the current module.
 2. Jedi only checks Array additions; ``list.pop``, etc are ignored.
 """
-from jedi.common import unite, safe_property
 from jedi import debug
 from jedi import settings
+from jedi import common
+from jedi.common import unite, safe_property
 from jedi._compatibility import unicode, zip_longest, is_py3
 from jedi.parser import tree
 from jedi.evaluate import compiled
 from jedi.evaluate import helpers
-from jedi.evaluate.cache import memoize_default
 from jedi.evaluate import analysis
 from jedi.evaluate import pep0484
-from jedi import common
-from jedi.evaluate.filters import DictFilter, AbstractNameDefinition, \
-    ParserTreeFilter
 from jedi.evaluate import context
 from jedi.evaluate import precedence
+from jedi.evaluate import recursion
+from jedi.evaluate.cache import memoize_default
+from jedi.evaluate.filters import DictFilter, AbstractNameDefinition, \
+    ParserTreeFilter
 
 
 class AbstractSequence(context.Context):
@@ -774,25 +775,21 @@ def _check_array_additions(context, sequence):
                         continue
 
                 random_context = context.create_context(name)
-                if context.evaluator.recursion_detector.push_stmt(power):
-                    # Check for recursion. Possible by using 'extend' in
-                    # combination with function calls.
-                    continue
-                try:
-                    found = helpers.evaluate_call_of_leaf(
-                        random_context,
-                        name,
-                        cut_own_trailer=True
-                    )
-                    if sequence in found:
-                        # The arrays match. Now add the results
-                        added_types |= find_additions(
+
+                with recursion.execution_allowed(context.evaluator, power) as allowed:
+                    if allowed:
+                        found = helpers.evaluate_call_of_leaf(
                             random_context,
-                            execution_trailer.children[1],
-                            add_name
+                            name,
+                            cut_own_trailer=True
                         )
-                finally:
-                    context.evaluator.recursion_detector.pop_stmt()
+                        if sequence in found:
+                            # The arrays match. Now add the results
+                            added_types |= find_additions(
+                                random_context,
+                                execution_trailer.children[1],
+                                add_name
+                            )
 
     # reset settings
     settings.dynamic_params_for_other_modules = temp_param_add

jedi/evaluate/recursion.py

@@ -7,75 +7,33 @@ Next to :mod:`jedi.evaluate.cache` this module also makes |jedi| not
 thread-safe. Why?  ``execution_recursion_decorator`` uses class variables to
 count the function calls.
 """
+from contextlib import contextmanager
+
 from jedi import debug
 from jedi import settings
 
 
 class RecursionDetector(object):
+    def __init__(self):
+        self.pushed_nodes = []
+
+
+@contextmanager
+def execution_allowed(evaluator, node):
     """
     A decorator to detect recursions in statements. In a recursion a statement
     at the same place, in the same module may not be executed two times.
     """
-    def __init__(self, evaluator):
-        self.top = None
-        self.current = None
-        self._evaluator = evaluator
+    pushed_nodes = evaluator.recursion_detector.pushed_nodes
 
-    def push_stmt(self, stmt):
-        self.current = _RecursionNode(self._evaluator, stmt, self.current)
-        check = self._check_recursion()
-        if check:
-            debug.warning('catched stmt recursion: %s against %s @%s', stmt,
-                          check.stmt, stmt.start_pos)
-            self.pop_stmt()
-            return True
-        return False
-
-    def pop_stmt(self):
-        if self.current is not None:
-            # I don't know how current can be None, but sometimes it happens
-            # with Python3.
-            self.current = self.current.parent
-
-    def _check_recursion(self):
-        test = self.current
-        while True:
-            test = test.parent
-            if self.current == test:
-                return test
-            if not test:
-                return False
-
-    def node_statements(self):
-        result = []
-        n = self.current
-        while n:
-            result.insert(0, n.stmt)
-            n = n.parent
-        return result
-
-
-class _RecursionNode(object):
-    """ A node of the RecursionDecorator. """
-    def __init__(self, evaluator, stmt, parent):
-        self._evaluator = evaluator
-        self.script = stmt.get_parent_until()
-        self.position = stmt.start_pos
-        self.parent = parent
-        self.stmt = stmt
-
-        # Don't check param instances, they are not causing recursions
-        # The same's true for the builtins, because the builtins are really
-        # simple.
-        self.is_ignored = self.script == self._evaluator.BUILTINS
-
-    def __eq__(self, other):
-        if not other:
-            return None
-
-        return self.script == other.script \
-            and self.position == other.position \
-            and not self.is_ignored and not other.is_ignored
+    if node in pushed_nodes:
+        debug.warning('catched stmt recursion: %s against %s @%s', node,
+                      node.start_pos)
+        yield False
+    else:
+        pushed_nodes.append(node)
+        yield True
+        pushed_nodes.pop()
 
 
 def execution_recursion_decorator(func):