Representing introduced, deprecated, and obsoleted versions at rest as optional
version tuples is redundant, since the empty version tuple already represents
"version not present".
NFC.
This request will finish type checking an AvailableAttr by resolving its domain
and then enforcing any restrictions that the domain has on the attribute, like
disallowing version specifications.
This change just introduces the request and plumbs it through. NFC.
Most of the compiler should use SemanticAvailableAttr instead. In contexts like
ASTDumper where a semantic attribute is unavailable use accessors on
AvailableAttr.
NFC.
Now that AvailableAttr has storage for its cached AvailabilityDomain, it's no
longer necessary to store an AvailabilityDomain inline in
SemanticAvailableAttr.
NFC.
It was difficult to preserve the existing, buggy behavior of availability
attribute inference with respect to attributes specifying availability for
non-platform-specific domains. Instead, this change improves attribute merging
by tracking every domain independently, and only merging attributes from the
same domain.
Put AvailabilityRange into its own header with very few dependencies so that it
can be included freely in other headers that need to use it as a complete type.
NFC.
This convenience returns an optional `SemanticAvailableAttr` (since in the
future, lookup of the `AvailabilityDomain` can fail). It replaces
`Decl::getDomainForAvailableAttr()`, since most callers will need to form a
`SemanticAvailableAttr` with the resulting domain anyways.
This new attribute iterator returned from the query makes it simpler to
implement algorithms that need access to both the `AvailableAttr *` and its
corresponding `AvailabilityDomain`. This is also work towards making it
possible to return an optional `AvailabilityDomain` from
`Decl::getDomainForAvailableAttr()`.
This query's functionality was not useful enough to be exposed on `Decl` and
cached in the request evaluator. Instead, just share a local implementation of
it in `TypeCheckAttr.cpp`.
Also remove the underlying `SemanticUnavailableAttrRequest`, which used memory
very inefficiently in order to cache a detailed answer to what was usually a
much simpler question.
The only remaining use of `Decl::getSemanticUnavailableAttr()` that actually
needed to locate the semantic attribute making a declaration unavailable was in
`TypeCheckAttr.cpp`. The implementation of the request could just be used
directly in that one location. The other remaining callers only needed to know
if the decl was unavailable or not, which there are simpler queries for.
# Please enter the commit message for your changes. Lines starting
It replaces `DeclAttr::getUnavailable()` and `AvailableAttr::isUnavailable()`
as the designated way to query for the attribute that makes a decl unavailable.
The renamed decl is now stored exclusively in the split request evaluator
storage, which is more efficient since most availability attributes do not
specify a renamed decl.
