ASTDumper was never updated to print extra conformance information,
like suppression, preconcurrency, etc. In default mode, we print it
as a comma-delimited list of source-like strings. In JSON mode, we
print objects containing flags.
* Move `AvailabilitySpec` handling logic to AST, so they can be shared
between libParse and ASTGen
* Requestify '-define-availability' arguments parsing and parse them
with 'SwiftParser' according to the 'ParserASTGen' feature flag
* Implement 'AvailableAttr' generation in ASTGen
This only takes the existing AST information and writes it as JSON
instead of S-expressions. Since many of these fields are stringified,
they're not ideal for the kind of analysis clients of the JSON format
would want to do. A future commit will update these values to use a
more structured representation.
This makes the low-level `print*` methods in `PrintBase` simply
forward to the writer, which does the actual work. Right now,
there's only the abstract base class for the writer and the
default (S-expression-like) writer. A later commit will
introduce the JSON writer.
Also update the `printField*` methods to take `Label`s instead
of `StringRef`s.
Availability specs are currently dumped by writing a pre-formatted
string directly to the output stream instead of using the structured
primitives in `PrintBase`. This needs to be fixed before we can
introduce the generalized writers.
The format here is meant to be the same as the format printed by
the original methods, but some colors may differ slightly when
dumping to the terminal.
ASTDumper allows nodes/values to be printed without labels, which
works fine for the default output but won't work for JSON when every
value needs to have a valid key. To balance these needs, we create
a `Label` abstraction that can be created as either `always` or
`optional`. All the current labels are treated as `always`, and all
other values have had `optional` labels associated with them, which
won't be printed in the default AST dump.
This change also adds a `printList` function that replaces anywhere
that `for` loops with `printRec` calls in their bodies. This will
be used to provide the necessary array structuring for JSON output
later. (There are some places where `for` loops call `printFlag`
which will need to be dealt with later.)
Most of the compiler should use SemanticAvailableAttr instead. In contexts like
ASTDumper where a semantic attribute is unavailable use accessors on
AvailableAttr.
NFC.
The platform field now indicates whether the attribute applies universally, to
a specific platform, to the Swift language, or to package descriptions.
Additionally the output now reflects whether or not the attribute specifies
unconditional deprecation or unavailabity or is `noasync`.
Introduce an `unsafe` expression akin to `try` and `await` that notes
that there are unsafe constructs in the expression to the right-hand
side. Extend the effects checker to also check for unsafety along with
throwing and async operations. This will result in diagnostics like
the following:
10 | func sum() -> Int {
11 | withUnsafeBufferPointer { buffer in
12 | let value = buffer[0]
| | `- note: reference to unsafe subscript 'subscript(_:)'
| |- warning: expression uses unsafe constructs but is not marked with 'unsafe'
| `- note: reference to parameter 'buffer' involves unsafe type 'UnsafeBufferPointer<Int>'
13 | tryWithP(X())
14 | return fastAdd(buffer.baseAddress, buffer.count)
These will come with a Fix-It that inserts `unsafe` into the proper
place. There's also a warning that appears when `unsafe` doesn't cover
any unsafe code, making it easier to clean up extraneous `unsafe`.
This approach requires that `@unsafe` be present on any declaration
that involves unsafe constructs within its signature. Outside of the
signature, the `unsafe` expression is used to identify unsafe code.
This attribute makes it so that a parameter of the annotated type, as well as
any type structurally containing that type as a field, becomes passed as
if `@_addressable` if the return value of the function has a dependency on
the parameter. This allows nonescapable values to take interior pointers into
such types.
Right now it is basically a version of nonisolated beyond a few simple cases
like constructors/destructors where we are pretty sure we want to not support
this.
This is part of my bringup strategy for changing nonisolated/unspecified to be
caller isolation inheriting.
Sema now type-checks the alternate ABI-providing decls inside of @abi attributes.
Making this work—particularly, making redeclaration checking work—required making name lookup aware of ABI decls. Name lookup now evaluates both API-providing and ABI-providing declarations. In most cases, it will filter ABI-only decls out unless a specific flag is passed, in which case it will filter API-only decls out instead. Calls that simply retrieve a list of declarations, like `IterableDeclContext::getMembers()` and friends, typically only return API-providing decls; you have to access the ABI-providing ones through those.
As part of that work, I have also added some basic compiler interfaces for working with the API-providing and ABI-providing variants. `ABIRole` encodes whether a declaration provides only API, only ABI, or both, and `ABIRoleInfo` combines that with a pointer to the counterpart providing the other role (for a declaration that provides both, that’ll just be a pointer to `this`).
Decl checking of behavior specific to @abi will come in a future commit.
Note that this probably doesn’t properly exercise some of the new code (ASTScope::lookupEnclosingABIAttributeScope(), for instance); I expect that to happen only once we can rename types using an @abi attribute, since that will create distinguishable behavior differences when resolving TypeReprs in other @abi attributes.
This attribute will allow you to specify an alternate version of the declaration used for mangling. It will allow minor adjustments to be made to declarations so long as they’re still compatible at the calling convention level, such as refining isolation or sendability, renaming without breaking ABI, etc.
The attribute is behind the experimental feature flag `ABIAttribute`.
Introduce an attribute to allow unsafe code within the annotated
declaration without presenting an unsafe interface to users. This is,
by its nature, and unsafe construct, and is used to document where
unsafe behavior is encapsulated in safe constructs.
There is an optional message that can be used as part of an audit
trail.
