Swift 5.1's lookup for custom attributes skipped associated type
members, which allowed code like the given example to compile. To
maintain source compatibility, identify the narrow case that happens
in practice---the property wrapper is at module scope but is now
shadowed by an associated type---warn about it, and accept it.
Fixes rdar://problem/56213175.
TypeCheckPattern used to splat the interface type into this, and
different parts of the compiler would check one or the other. There is
now one source of truth: The interface type. The type repr is now just
a signal that the user has written an explicit type annotation on
a parameter. For variables, we will eventually be able to just grab
this information from the parent pattern.
mode and separate out the code for top-level evaluation from the normal
step-by-step evaluation. This ensures that step-by-step evaluation
does not accidentally rely on any logic meant for top-level evaluation.
This change should not affect the observable behavior of the evaluator.
validateDecl() no longer explicitly validates the result TypeLoc.
Instead, the request is triggered via validateDecl() calling
computeType() on the FuncDecl or SubscriptDecl.
Since getSpecifier() now kicks off a request instead of always
returning what was previously set, we can't pass a ParamSpecifier
to the ParamDecl constructor anymore. Instead, callers either
call setSpecifier() if the ParamDecl is synthesized, or they
rely on the request, which can compute the specifier in three
specific cases:
- Ordinary parsed parameters get their specifier from the TypeRepr.
- The 'self' parameter's specifier is based on the self access kind.
- Accessor parameters are either the 'newValue' parameter of a
setter, or a cloned subscript parameter.
For closure parameters with inferred types, we still end up
calling setSpecifier() twice, once to set the initial defalut
value and a second time when applying the solution in the
case that we inferred an 'inout' specifier. In practice this
should not be a big problem because expression type checking
walks the AST in a pre-determined order anyway.
After this change, we only use one single hash table for USR to USR id
mapping. The basic source locations are an array of fixed length
records that could be retrieved by using the USR id since each
USR id is guaranteed to be associated with one basic location entry.
The source file paths are refactored to a blob of 0-terminated strings.
Decl locations use offset in this blob to refer to the source file path
where the decl was defined.
