This includes being able to define a class that was previously
forward-declared, and being able to define a member function out-of-line
that was previously declared inside a class.
No support for fields or methods yet, and a class definition doesn't yet
cause the class to be treated as a complete type.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
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.
Using the computed value representation, fix lowering of struct and
tuple values to use the value representation rather than the object
representation. Fixes an issue found in the review of #3257.
This currently causes us to compute value representations of all types
as they are created, which generates substantially more SemIR to
represent types. We can get some of that back by deferring computation
of the value representation until the type is required to be complete,
but some of the additional cost here will persist with this approach.
I also considered making the computation of the value representation
type be something that lives entirely within the lowering phase, but I
think that's not the right approach in the longer term, because the
value representation will be semantically visible and relevant once we
start allowing it to be customized.
We should consider moving the nodes that exist to compute canonical
non-local types, including value representations, out into a separate
global block. That will clean up the SemIR representation substantially,
and make the SemIR produced for a function not depend on which types we
happen to have encountered beforehand. But that's not being done in this
PR.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
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.
Also add `name_reference_untyped` for references to non-first-class
names without types, which currently covers namespaces and functions.
This improves the fidelity of the SemIR representation, and fixes some
issues where we would use the wrong location for nodes and diagnostics
downstream of a name reference.
We're still missing a representation for dotted name expressions, such
as `Namespace.Function`, and we don't use the `untyped` node as an
operand of any other node yet.
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.
This makes the difference between errors and lower-level diagnostics
visible to users, and aligns the toolchain's behavior with the
expectations in `driver_fuzzer.cpp`.
Fix a bug where we would perform the computation of the return location
in SemIR after we have already used it in some cases, leading to
assertion failures during lowering. Instead, accumulate a sequence of
instructions to compute the return location in a temporary block, and
overwrite the return slot with those instructions when we perform
initialization.
StubReference is replaced by a more general SpliceBlock node, that takes
a code block and a result value, executes the instructions in the block,
and produces the result. This is used in the uncommon case where more
than one instruction is required to compute the return slot, which can
happen if we need to first emit a temporary and then index into it, or
if we need to perform multiple levels of indexing before we reach an
entity to initialize.
The speculative insertion of StubReferences after elements in an
argument list turned out to not be necessary, because we decided we want
to insert per-argument initialization steps after all arguments are
evaluated, rather than interleaving them. The StubReferences we insert
are causing some minor code complexity, so remove them.
We still create StubReferences when performing patch-ups of
already-emitted code, but we no longer ever need to look through them
when determining whether an initializer was a literal or when evaluating
a type expression.
This implements initializing expression semantics for structs and
tuples, following #2006 and discussions since.
Tuple and (and analogously, struct) literals are treated as having a
mixed expression category that is later resolved based on how the
literal is used, as either a tuple initializer or a tuple value, at
which point we create a `TupleInit` or `TupleValue` that represents the
formation of the tuple initializer or tuple value from the tuple
literal.
There's quite a lot of TODOs here, and the SemIR representation is still
not quite right, but this seems like a good place to checkpoint some
incremental progress.
- `Peek()` no longer returns a useful value, because we often don't
allocate a `NodeBlockId` until we finish building the block. Remove it
and update both its callers.
- Rename `PeekForAdd()` to `PeekOrAdd()` since it's no longer used to
get a block ID to add elements into.
- `PushForAdd()` was unused. Remove it.
- Add `NodeBlockStack::AddNode` to combine the operations of adding a
node and inserting it into a block.
Instead of modeling array initialization as a thin wrapper around tuple
initialization, handle it like a function call, with a return slot as
part of its input. This better matches how initialization via a call to
`ImplicitAs::Convert` will eventually work, and in particular lets us do
in-place initialization of arrays rather than always creating a
temporary.
`SemIR` now only stores complete blocks, and placeholders for blocks
where we need a block ID before we know the block contents.
This is a preparation step towards the new node block allocation design.
Building on #3214 and #3215, updates sem_ir yaml to be:
```
- filename: name
sem_ir: [ ... ]
```
Also, changes the textual format from `package { ... }` to `file
<filename> { ... }`. My thought on packages there is:
```
file "foo.carbon" {
package MyPackage
...
}
```
The reason for putting the file first is that it's easier if we put what
we're grouping on first, whereas the package is an "annotation" on the
file.
This better reflects the purpose of these semantics nodes, and prepares
for adding TupleValue and TupleInit nodes to represent forming values
and initializers from literals.
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 SmithandJon Ross-Perkins
josh11bandRichard Smith
Geoff Romer