These .rst files are also included during HTML generation so they are also
viewable online (as noted above) at e.g.
`http://llvm.org/docs/CommandGuide/Foo.html`.
+
+Checking links
+==============
+
+The reachibility of external links in the documentation can be checked by
+running:
+
+ cd docs/
+ make -f Makefile.sphinx linkcheck