Split viewcode and linkcode tests out of main test root.

tests/roots/test-ext-viewcode/conf.py

@@ -1,8 +1,24 @@
-# -*- coding: utf-8 -*-
-
-import sys
-import os
-
-sys.path.insert(0, os.path.abspath('.'))
-extensions = ['sphinx.ext.autodoc', 'sphinx.ext.viewcode']
-master_doc = 'index'
+# -*- coding: utf-8 -*-
+
+import sys
+import os
+
+sys.path.insert(0, os.path.abspath('.'))
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.viewcode']
+master_doc = 'index'
+
+
+if 'test_linkcode' in tags:
+    extensions.remove('sphinx.ext.viewcode')
+    extensions.append('sphinx.ext.linkcode')
+
+    def linkcode_resolve(domain, info):
+        if domain == 'py':
+            fn = info['module'].replace('.', '/')
+            return "http://foobar/source/%s.py" % fn
+        elif domain == "js":
+            return "http://foobar/js/" + info['fullname']
+        elif domain in ("c", "cpp"):
+            return "http://foobar/%s/%s" % (domain,  "".join(info['names']))
+        else:
+            raise AssertionError()