PATCH: Making the DWARF constants type-safe

[Eric Christopher]

On Mon, Oct 21, 2013 at 9:53 AM, David Blaikie <dblaikie at gmail.com> wrote:
> After spending some time parallel debugging Clang and GCC I've been
> frustrated by Clang's use of raw integer types for form/tag/etc (compared to
> GCC which uses specific enum types for those variables - making it easier to
> print their textual or integer values as needed, rather than only the
> integer values).
>
> To improve this, here's a patch that separates out the dwarf constants into
> separate groups, named the same as GCC's (for want of any better names) and
> uses them in the lib/CodeGen/AsmPrinter Dwarf handling code.
>
> Probably the major debatable portion of this is how we handle DWARF blocks.
> They're treated as DIEs and have attributes added to them. Generally those
> attributes have no attribute type (using zero) - since that's not a valid
> DWARF attribute kind number the code didn't compile anymore. I could've
> added casts all over the place but instead opted to put a few wrapper
> functions to make it a bit more type safe - such that the attribute can be
> omitted for certain 'add' operations but only if the DIE is actually a
> block.
>
> I don't really know enough to understand whether it makes sense for blocks
> to be DIEs or how we should handle their attributes not having attribute
> types here, so I figured I'd throw this out there in case I'm missing
> something here.

I don't really know that blocks need to be DIEs, mostly they want to
be tuples/lists of some sort. We're just using DIEs to represent the
"it's a form and a length and some stuff".

It's a great step though so thanks.

-eric