Provides a centeralized table for all intrinsic overloads.
IntrinsicTable::Lookup() takes the intrinsic type and list of arguments, returning either the matched overload, or a sensible error message.
The validator has expectations that the TypeDeterminer resolves the return type of an intrinsic call, even when the signature doesn't match. To handle this, create semantic::Intrinsic nodes even when the overload fails to match. A significant portion of the Validator's logic for handling intrinsics can be removed (future change).
There are a number of benefits to migrating the TypeDeterminer and Validator over to the IntrinsicTable:
* There's far less intrininsic-bespoke code to maintain (no more duplicate `kIntrinsicData` tables in TypeDeterminer and Validator).
* Adding or adjusting an intrinsic overload involves adding or adjusting a single Register() line.
* Error messages give helpful suggestions for related overloads when given incorrect arguments.
* Error messages are consistent for all intrinsics.
* Error messages are far more understandable than those produced by the TypeDeterminer.
* Further improvements on the error messages produced by the IntrinsicTable will benefit _all_ the intrinsics and their overloads.
* The IntrinsicTable generates correct parameter information, including whether parameters are pointers or not.
* The IntrinsicTable will help with implementing autocomplete for a language server
Change-Id: I4bfa88533396b0b372aef41a62fe47b738531aed
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/40504
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Ben Clayton