struct Hello : public FunctionPass {
-This declares a "``Hello``" class that is a subclass of `FunctionPass
+This declares a "``Hello``" class that is a subclass of :ref:`FunctionPass
<writing-an-llvm-pass-FunctionPass>`. The different builtin pass subclasses
are described in detail :ref:`later <writing-an-llvm-pass-pass-classes>`, but
for now, know that ``FunctionPass`` operates on a function at a time.