From 37f2b8ff56a1918335bd76dbedeea2cea6ee9677 Mon Sep 17 00:00:00 2001
From: David Halter <davidhalter88@gmail.com>
Date: Mon, 9 Jul 2012 12:05:07 +0200
Subject: [PATCH] recursions are now being catched

---
 evaluate.py                        | 11 ++++++--
 helpers.py                         | 45 ++++++++++++++++++++++++++++++
 test/completion/functions.py       | 17 +++++++++--
 test/completion/thirdparty/jedi.py |  2 +-
 4 files changed, 70 insertions(+), 5 deletions(-)
 create mode 100644 helpers.py

diff --git a/evaluate.py b/evaluate.py
index be452ee7..5111b671 100644
--- a/evaluate.py
+++ b/evaluate.py
@@ -30,6 +30,7 @@ import parsing
 import modules
 import debug
 import builtin
+import helpers
 
 memoize_caches = []
 
@@ -70,6 +71,8 @@ def clear_caches():
     for m in memoize_caches:
         m.clear()
 
+    #follow_statement.reset()
+
 
 def memoize_default(default=None):
     """
@@ -209,7 +212,8 @@ class Instance(Executable):
 
     def __getattr__(self, name):
         if name not in ['line_nr', 'indent', 'name', 'get_imports']:
-            raise AttributeError("Don't touch this (%s)!" % name)
+            raise AttributeError("Instance %s: Don't touch this (%s)!"
+                                    % (self, name))
         return getattr(self.base, name)
 
     def __repr__(self):
@@ -976,7 +980,9 @@ def assign_tuples(tup, results, seek_name):
             if hasattr(r, "get_exact_index_types"):
                 types += r.get_exact_index_types(index)
             else:
-                debug.warning("assign tuples: invalid tuple lookup")
+                debug.warning("invalid tuple lookup %s of result %s in %s"
+                                    % (tup, results, seek_name))
+
         return types
 
     result = []
@@ -1002,6 +1008,7 @@ def assign_tuples(tup, results, seek_name):
     return result
 
 
+@helpers.RecursionDecorator
 @memoize_default(default=[])
 def follow_statement(stmt, scope=None, seek_name=None):
     """
diff --git a/helpers.py b/helpers.py
new file mode 100644
index 00000000..d715bade
--- /dev/null
+++ b/helpers.py
@@ -0,0 +1,45 @@
+import parsing
+
+class RecursionDecorator(object):
+    """ A decorator to detect recursions in statements """
+    def __init__(self, func):
+        self.func = func
+        self.reset()
+        self.current = None
+
+    def __call__(self, stmt, *args, **kwargs):
+        # don't check param instances, they are not causing recursions
+        if isinstance(stmt, parsing.Param):
+            return self.func(stmt, *args, **kwargs)
+
+        r = RecursionNode(stmt, self.current)
+        if self.check_recursion(r):
+            return []
+        parent, self.current = self.current, r
+        result = self.func(stmt, *args, **kwargs)
+        self.current = parent
+        return result
+
+    def check_recursion(self, new):
+        test = self.current
+        while True:
+            if new == test:
+                return True
+            if not test:
+                return False
+            test = test.parent
+
+    def reset(self):
+        self.top = None
+        self.current = None
+
+class RecursionNode(object):
+    def __init__(self, stmt, parent):
+        self.script = stmt.get_parent_until()
+        self.position = (stmt.line_nr, stmt.indent)
+        self.parent = parent
+
+    def __eq__(self, other):
+        if not other:
+            return None
+        return self.script == other.script and self.position == other.position
diff --git a/test/completion/functions.py b/test/completion/functions.py
index 2fd468d9..bdab15a6 100644
--- a/test/completion/functions.py
+++ b/test/completion/functions.py
@@ -54,7 +54,7 @@ variable_rename(list())().
 variable_rename(1)().
 
 # -----------------
-# recursion (should ignore)
+# recursions (should ignore)
 # -----------------
 def recursion(a, b):
     if a:
@@ -62,9 +62,22 @@ def recursion(a, b):
     else:
         return recursion(a+".", b+1)
 
-##? int() float()
+#? int() float()
 recursion("a", 1.0)
 
+def other(a):
+    return recursion2(a)
+
+def recursion2(a):
+    if a:
+        return other(a)
+    else:
+        return recursion2("")
+    return a
+
+#? int() str() str()
+recursion2(1)
+
 # -----------------
 # ordering
 # -----------------
diff --git a/test/completion/thirdparty/jedi.py b/test/completion/thirdparty/jedi.py
index 5892efe2..d0f524d9 100644
--- a/test/completion/thirdparty/jedi.py
+++ b/test/completion/thirdparty/jedi.py
@@ -17,5 +17,5 @@ scopes, path, dot, like = \
 #? set()
 el = scopes.
 
-##? str() <--- recursion
+#? str() <--- recursion
 el = evaluate.get_names_for_scope()[0].