Attribute documentation

[Aaron Ballman]

(Removing llvm-admin since this doesn't concern them.)

On Mon, Feb 10, 2014 at 2:21 PM, Reid Kleckner <rnk at google.com> wrote:
> I'm conflicted about this.  The less time I spend editing .td files, the
> happier I am.  Vim has reasonable support for highlighting and editting rst
> out of the box, and I'd rather edit full text in that directly.
>
> We're pretty good at keeping LLVM's LangRef.rst up to date through code
> review.  Could we use the same approach with something in
> docs/AttributesReference.rst, or do people think it would quickly become
> stale?

We could, but I believe this approach is an improvement. For starters,
it's a way that we can *require* attributes to have some documentation
which is a drastic improvement over the LangRef.rst approach (at least
as far as users are concerned). Also, there are things we can
automatically generate for attributes which would require duplicated
effort if it was done manually (such as what syntaxes are supported,
what subjects the attribute can appertain to, etc). The declarative
nature of the attribute tablegen lends itself nicely to this sort of
automation.

Honestly, I think the benefits are significant enough to warrant this approach.

~Aaron