Incomplete types may be nested within other types; for example, a tuple
type might have an incomplete type as an element. Handle such cases by
walking through nested incomplete types when completing a type. This is
done non-recursively in case a very complex type is formed.
Types are generally no longer completed at the point where they're
formed. Instead, we attempt to complete a type when it is used in a
context that requires a complete type, and diagnose if the type cannot
be completed at that point. This will be necessary for classes, which
can become complete after their first use, and helps tease out bugs
where a type completeness check is missing.
Bug found by fuzzing. Problem was untyped SemIR nodes had an invalid
type id, which was retrieved by `HandlePrefixOperator` and then passed
to `context.GetUnqualifiedType`, ultimately performing an invalid access
in `semantics_ir_->GetNode`.
We prefer to make a placeholder type for functions and namespaces to
remove the need for checking for the untyped case everywhere. Eventually
functions will have their own types, but this approach will be needed
for namespaces (and perhaps other non-first-class entities like unbound
methods and interface members) long term.
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
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
josh11bandRichard Smith
Jon Ross-Perkins