add a dummy builder, for syntax checkers

AUTHORS

@@ -24,6 +24,7 @@ Other contributors, listed alphabetically, are:
 * Charles Duffy -- original graphviz extension
 * Kevin Dunn -- MathJax extension
 * Josip Dzolonga -- coverage builder
+* Buck Evan -- dummy builder
 * Hernan Grecco -- search improvements
 * Horst Gutmann -- internationalization support
 * Martin Hans -- autodoc improvements

CHANGES

@@ -6,6 +6,7 @@ Incompatible changes
 
 Features added
 --------------
+* Added the ``dummy`` builder: syntax check without output.
 
 Bugs fixed
 ----------

doc/builders.rst

@@ -309,6 +309,18 @@ for details.
 
    .. autoattribute:: supported_image_types
 
+.. module:: sphinx.builders.dummy
+.. class:: DummyBuilder
+
+   This builder produces no output.  The input is only parsed and checked for
+   consistency.  This is useful for linting purposes.
+
+   .. autoattribute:: name
+
+   .. autoattribute:: supported_image_types
+
+   .. versionadded:: 1.4
+
 .. module:: sphinx.builders.linkcheck
 .. class:: CheckExternalLinksBuilder
 

sphinx/builders/dummy.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+"""
+    sphinx.builders.dummy
+    ~~~~~~~~~~~~~~~~~~~~
+
+    Do syntax checks, but no writing.
+
+    :copyright: Copyright 2007-2015 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+
+from sphinx.builders import Builder
+
+
+class DummyBuilder(Builder):
+    name = 'dummy'
+    allow_parallel = True
+
+    def init(self):
+        pass
+
+    def get_outdated_docs(self):
+        return self.env.found_docs
+
+    def get_target_uri(self, docname, typ=None):
+        return ''
+
+    def prepare_writing(self, docnames):
+        pass
+
+    def write_doc(self, docname, doctree):
+        pass
+
+    def finish(self):
+        pass