(and similar for flag_enum)
This commit prepares the importer for a world in which NS_ENUM and
NS_OPTIONS have adopted the new Clang attributes 'enum_extensibility'
and 'flag_enum', but API notes are used to reverse the effect. Without
this there would be no transition path for adopting the standard Cocoa
macros, which have applied unconditionally up to now.
rdar://problem/18744821
These new Clang attributes identify whether an enum is intended to
represent an option set or not, and whether the set of cases listed in
the enum declaration is exhaustive. (Swift doesn't currently have a
closed/open distinction for enums, so treat any C enum with
enum_extensibility as a proper closed Swift enum, like we do with
NS_ENUM.)
Enums with neither attribute will continue to be imported as unique
types.
rdar://problem/28476618
Now that we have a EnumInfoCache per NameImporter which is per Clang
instance, we can just cache our EnumInfo based off of Clang decl,
rather than using a faux-USR technique. This greatly speeds up and
simplifies enum imports.
EnumInfos are requested about 200k times when building the module
cache for Foundation, and thousands of times for simple tests during
normal import, so efficiency here is important. While building module
caches, the EnumInfoCache is hit 99% of the time, and it is hit 98% of
the time during normal import with pre-built module caches.
NFC.
Introduces new files ClangAdapter.h/cpp, which will serve as a
convenient place to put code reasoning about Clang details. Refactors
out most Clang-related is*, has*, and get* methods from the
ImporterImpl. In the future, an adapter class could help serve to
seperate the concerns of the importer from the details of how to
correctly use Clang APIs.
Pull off the caching code from the Impl and onto a new EnumInfoCache
class, that will be useful as we decouple import naming from the Impl
class state.
The Clang attribute allows one to state that a particular enumeration
type describes an error, and associates it with a particular domain
constant. However, due to lack of API notes support, this attribute
wasn't actually getting used. Instead, we had a number of explicit
extensions to enum types to make them conform to the _BridgedNSError
protocol explicitly.
Now that we have API notes, use them to make these enums into error
enums with the appropriate domain, so that the Clang importer will
synthesize the _BridgedNSError conformances. Then, remove all of the
explicit conformances---and with them, the overlays for 12 frameworks.
There is a small fix to more eagerly consider these conformances as
"used" if an expression is formed with the error enum as a value
type. This better ensures that the conformances will be available at
runtime when needed.
This cleanup is needed to implement SE-0112 (NSError bridging),
although it is useful by itself.
Rather than do whole-word common-word stripping, we only strip common
prefixes. This is not as powerful as what was originally intended, but
much less magical in the mapping into Swift.
Test case adjusted, and common utility functions exposed.
This is more of rdar://problem/24869070; StringRefs are leaking out of
importFullName still, in a DenseMap that can get deallocated. When we
cache this data, put them in "permanent" (Swift ASTContext) storage.
ns_error_domain can now be used to communicate with the ClangImporter
when an enum has an associated error domain string. In this case, when
we import it as a Swift enum, we can also synthesize a conformance to
_BridgedNSError.
This allows the creation of something like NS_ERROR_ENUM, in which the
developer can declare an enum for the purposes of error handling. Adds
Sema and executable tests demonstrating this funcionality.
In order for the imported ns_error_domain bridging to work, we have to
at some point forcibly pull in a _BridgedNSError conformance, as one
will not be pulled in normally. This is a problem, and is explicitly
signaled in the provided test case
Introduces new class, EnumInfo, just for the implementation of the
ClangImporter to encapsulate various computed information about the
enum we're importing.
This helps refactor some functionality, aids clarity, and also
prevents us from repeating calculations multiple times, as we were
doing with classifyEnum's macro-expansion tracking. Provides a base
where we can add more heavy lifting in classifyEnum in the future.
