The `unchecked_ref_cast` is designed to be able to cast between
`Optional<ClassType>` and `ClassType`. We need to handle these cases by
checking if the type is optional and adjust the path accordingly.
When printing diagnostics, category names are printed as [#<category-name>]
at the end of a diagnostic. For all of the category names that are mentioned
in this manner, print "footnotes" at the end of compilation providing
documentation references to each category, e.g.,
[#deprecated]: <http://example.com/deprecated>
[#StrictMemorySafety]: <http://example.com/memory-safety>
Right now, these point into the markdown files in the installed toolchain,
same as the URLs behind references. That is subject to change in the future.
When deserialization a protocol conformance from a binary swiftmodule
file the compiler can encounter inconsistencies caused by stale module
files. Replace the hard crash with a proper error and print the list of
requirements and conformances being compared to stderr for manual
inspection. Recover silently when we can afford to, during indexing or
in LLDB.
Failures in `readNormalProtocolConformanceXRef` are usually caused by a
dependency change without the required rebuild of its dependents.
Display a proper error instead of crashing when encountering such an
issue during normal compilation. Recover silently when we can afford to,
during indexing or in LLDB.
Introduce a new deserialization mode `enableExtendedDeserializationRecovery`
for use when we can afford inconsistent information from a swiftmodule
file. It's enabled automatically in debugger mode, when user errors are
allowed and during index-while-building.
* factor out common methods of AST Type/CanonicalType into a `TypeProperties` protocol.
* add more APIs to AST Type/CanoncialType.
* move `MetatypeRepresentation` from SIL.Type to AST.Type and implement it with a swift enum.
* let `Builder.createMetatype` get a CanonicalType as instance type, because the instance type must not be a lowered type.
Introduction, deprecation, and obsoleteion ranges should only be returned by
the accessors on `SemanticAvailableAttr` when the attribute actually has an
affect on the corresponding kind of availability.
`AvailabilityRange` is now being used as a currency type in more of the
compiler, and some of those uses are in permanent `ASTContext` allocations. The
class wraps the `VersionRange` utility, which is itself a wrapper around
`llvm::VersionTuple` with some additional storage for representing sentinel
values. Even though the two sentinel values can be be represented with just a
single bit of additional storage on top of the 16 bytes required to represent
`VersionTuple`, because of alignment requirements the sentinel values end up
bloating the layout of `VersionRange` by many bytes.
To make `AvailabilityRange` and `VersionRange` more efficient to store, we can
instead reserve two unlikely `llvm::VersionTuple` bit patterns as the sentinel
values instead. The values chosen are the same ones LLVM uses to represent
version tuple tombstones and empty keys in a `DenseMap`.
Introduce a constructor that takes an `llvm::VersionTuple` directly, instead of
needing to spell out `VersionRange::allGTE(<tuple>)` which is unnecessarily
verbose.
