tree 5737a2efafc41becacca4b44c88d34899179177d
parent be6fb2a8d2f3c574ef0b3ced7b19c3a6541ece35
author Ben Clayton <bclayton@google.com> 1655470131 +0000
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> 1655470131 +0000

tint/ast: Derive off `ast::Variable`

Add the new classes:
* `ast::Let`
* `ast::Override`
* `ast::Parameter`
* `ast::Var`

Limit the fields to those that are only applicable for their type.

Note: The resolver and validator is a tangled mess for each of the
variable types. This CL tries to keep the functionality exactly the
same. I'll clean this up in another change.

Bug: tint:1582
Change-Id: Iee83324167ffd4d92ae3032b2134677629c90079
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/93780
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>