Implement toolchain support for `returned var` and `return var`.
- Modeled `returned` in the parse tree as a `ReturnedSpecifier`
appearing after the `VariableIntroducer`.
- Modeled `return var` in the parse tree as a `ReturnVarSpecifier`
appearing after the `ReturnStatementStart`.
- Factored out the implementation of `return` statement and `returned
var` handling in check into a new `return.{h,cpp}`. The parse nodes
themselves are still handled in `handle_*.cpp`. This allows easy code
reuse between `return` and `returned var`.
This replaces the use of `VarStorage` in this case.
Add an `UnboundFieldType` type as the type of a field, in cases where
it's referenced without an accompanying object.
Add a `BindName` node to describe the name binding performed for both
variables and fields so that we can handle them more uniformly.
1. In general, `semantics_ir` -> `sem_ir`, to match the directory name.
2. For the list of `ValueStore`-related accessors on `SemIR::File`, add
them to `check`'s `Context` object, shortening access.
Finishing what #3316 started, add more bespoke ValueStore-like
structures to File. With this, the things which previously had somewhat
boilerplate Add/Get functions are now all on side classes, giving a
uniform style of API for calling.
Note, I was on the fence about making things public on ValueStore. If
it's preferred that I make some things there protected I certainly can,
there's just a trade-off that may mean more distinct child/wrapper
types.
Split `node.h` into separate files for ID types (`id.h`) and for typed
nodes (`typed_nodes.h`). The per-node-kind data is now specified as part
of declaring the typed nodes, and is removed from the node kinds
x-macros, which now simply enumerate the node kinds.
Replace `SemIR::Node::GetAsFoo` and `SemIR::Node::Foo::Make` with
`SemIR::Foo` class that represents a particular kind of node, with named
fields.
Rename `SemIR::IntegerLiteral` and `SemIR::RealLiteral` to
`IntegerValue` / `RealValue` to better reflect their purpose and avoid a
name collision with the corresponding `SemIR` node kinds.
Remove `NodeKind::Invalid` and the `SemIR::Node` default constructor
entirely, as they were not used for anything.
Combine the initialization, implicit conversion, and value category
conversion functions into a single function.
This substantially reduces the duplication between these steps, and
ensures that we support the same set of conversions in all these
contexts. This also fixes some issues where we would not use the proper
value representation for tuples and structs after performing implicit
conversions.
Continuing along with #3070. Note this is just a file rename, with BUILD
edits; every file previously in semantics/ should show as moved (except
maybe BUILDs, which split).
Richard Smith
josh11b
Jon Ross-Perkins