In preparation for shifting from `TypeId`s potentially representing
attached types to always representing unattached types, using
[terminology suggested on
Discord](https://discord.com/channels/655572317891461132/963846118964350976/1359286326779973712).
This change causes us to track slightly more type spelling information
through SemIR.
One change that has significant impact on the SemIR output is that we
now build a `struct_type` instruction in each class representing the
types of the fields, including the spelling used for those types. This
is now no longer always identical to the corresponding canonical
`struct_type` for the object representation, so it's built separately
and owned by the class.
Also remove `TypeBlock` support entirely, as its only use was
representing `TupleType`s, which now use an `InstBlock`.
When converting to a facet there are three different failure modes:
1. You provided a non-type value. Only types can convert to facets. So
we tell you that we found a non-type value.
2. You provided a facet type (which has type TypeType) which does not
have witnesses for the the target facet's type. So we tell you that the
type `T` implements `X` but needs to implement `Y`.
2. You provided a (non-facet-type) concrete type (of type TypeType)
which does not implement the target facet's type (which is a FacetType).
So we tell you that we need the type to implement the FacetType but it
does not.
3. You provided a FacetAccessType (which is of type TypeType also, but
we special case this), whose underlying FacetType is not compatible with
the target facet's type. So we tell you that we need the type to
implement `X` but found a FacetAccessType `T` which implements `Y`.
Closes#5027
TODO to resolve whether it should conditionally say "object of"
depending on the category
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Changes the name of SemIR `import_ref`s to use the format
`<package>.<entity>`.
<table>
<tr><th>Before</th><th>After</th></tr>
<tr>
<td><code>%import_ref.05a: type</code></td>
<td><code>%Main.D: type</code></td>
</tr>
<tr>
<td><code>%import_ref.8f2: <witness></code></td>
<td><code>%Main.import_ref.8f2: <witness></code></td>
</tr>
</table>
* [Discord discussion in
#toolchain](https://discord.com/channels/655572317891461132/655578254970716160/1330253540999827577)
* Closes#4769
This removes some churn when adding new diagnostic cases to test files
(where previous to this change the newly added newline would cause the
previous diagnostic CHECKs to be updated including changes to the line
number because the CHECK for the blank line meant an extra line between
CHECK and source line).
A few alternatives discussed here:
https://discord.com/channels/655572317891461132/655578254970716160/1329573358475673723
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Add a Vtable typed inst with a type_id (of the type this vtable applies
to) and list of virtual function decls (or import refs to function
object constants).
This doesn't add lowering/emission of the vtable, or usage when
initializing objects of the type.
Some questions in case they're interesting to discuss:
* is it right/worth having the type_id in the vtable? (probably makes it
easier to emit - using the type to get the class name to figure out the
mangled name for the vtable) perhaps it should be a ClassId?
* I'm thinking the logic in CheckCompleteClassType could be the place we
handle diagnostics for mismatched keywords (virtual/abstract for a
function that's already virtual/abstract, maybe checking for non-virtual
functions with the same name in a base class, or derived class functions
without `impl`, etc) - but we could move some of that to the moment we
walk the function decl, and record our findings in the function decl
(record the base function it overrides, or the index of the vtable to
slot to use when building the vtable at the end of the class)
* the Vtable typed inst has `constant_kind = InstConstantKind::Always`
and `is_lowered = false`, I think I added that in to workaround/address
some failures in lowering. And seems correct for this intermediate step
- I'll add lowering in a follow-up patch. But the constant_kind - what
should this be? We can just say all vtables are of VtableType (in which
case the `Always` constant kind sounds right to me) or we could have
them introduce a type with each virtual function as a named member,
even?
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
When printing a Class, the complete_type_witness was printed last but
this gave a somewhat misleading representation as it appeared to be part
of the !members label. Move it above the label so that the label more
clearly refers to everything below it.
Include the index rather than the name in the fingerprint of a symbolic
binding. While both the index and the name contribute to the canonical
identity, using either one of them in the fingerprint is sufficient to
ensure that distinct entities get different fingerprints. Changing the
name of a symbolic binding should ideally not result in fingerprint
changes, so exclude the name from the fingerprint when we have an index.
Use the canonical type and constraint when fingerprinting an impl, so
that uses of names in `name_ref` instructions aren't considered, only
the entity the name resolves to, and different ways of spelling the same
type have the same fingerprint. This similarly allows compatible changes
to be made to impls without changing the fingerprint.
Exclude the declaration block when determining the fingerprint of a
declaration. The declaration block contains the declarations of
parameters of the declaration, which do affect whether two declarations
are identical, but not whether they denote the same entity, because it
would be invalid to have different declaration blocks for declarations
with the same name in the same scope. Therefore changes to the
declaration block are compatible, and it's useful for such changes to
not affect the fingerprint.
This is not easy to test in isolation with our current testing
machinery. However, a follow-on PR will change the name of a parameter
in the prelude, and with this in place, will not cause any changes to
occur elsewhere in the toolchain tests.
Use it in the instruction namer to make instruction names more stable
across unrelated changes to the toolchain or the prelude.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
This is a precondition for enabling the new pattern-matching subsystem
to support binding patterns that have `if` expressions in the type
position.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
For example, format the `ImplicitAs` interface as `Core.ImplicitAs`
rather than simply `ImplicitAs`.
When importing an entity in a namespace, also import a declaration of
the enclosing namespace if necessary so that we can determine its name.
This slightly improves the handling of adapters, by making them copyable
in some cases when their adapted type is copyable.
Refactor some of the repeated checks for properties of value
representations.
In passing, move all the adapter tests in check/testdata/class to a
subdirectory since we now have quite a few of them.
Richard Smith
Dana Jansens
Geoff Romer
josh11bandJosh L
Boaz Brickner
Calvin
David Blaikie
