From 5e439cbbb5f791d39ad27f55ea594ad0ef935966 Mon Sep 17 00:00:00 2001
From: Georg Brandl <georg@python.org>
Date: Mon, 15 Jun 2009 17:31:29 +0200
Subject: [PATCH] #196: Add a warning if an extension module doesn't have a
 ``setup()`` function.

---
 CHANGES                   |  3 +++
 sphinx/application.py     |  5 ++++-
 tests/test_application.py | 10 ++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 72bef47bf..069b3ce53 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,9 @@
 Release 0.6.2 (in development)
 ==============================
 
+* #196: Add a warning if an extension module doesn't have a
+  ``setup()`` function.
+
 * #158: Allow '..' in template names, and absolute template paths;
   Jinja 2 by default disables both.  
 
diff --git a/sphinx/application.py b/sphinx/application.py
index 62b0c53d6..7e926e572 100644
--- a/sphinx/application.py
+++ b/sphinx/application.py
@@ -167,7 +167,10 @@ class Sphinx(object):
         except ImportError, err:
             raise ExtensionError('Could not import extension %s' % extension,
                                  err)
-        if hasattr(mod, 'setup'):
+        if not hasattr(mod, 'setup'):
+            self.warn('extension %r has no setup() function; is it really '
+                      'a Sphinx extension module?' % extension)
+        else:
             mod.setup(self)
         self._extensions[extension] = mod
 
diff --git a/tests/test_application.py b/tests/test_application.py
index 6425e2753..a113c2359 100644
--- a/tests/test_application.py
+++ b/tests/test_application.py
@@ -57,3 +57,13 @@ def test_output():
         assert app._warncount == old_count + 1
     finally:
         app.cleanup()
+
+
+def test_extensions():
+    status, warnings = StringIO(), StringIO()
+    app = TestApp(status=status, warning=warnings)
+    try:
+        app.setup_extension('shutil')
+        assert warnings.getvalue().startswith("WARNING: extension 'shutil'")
+    finally:
+        app.cleanup()