**Overview**:
This PR introduces the basic infrastructure needed to eventually migrate
derived macros generation from hand-crafted AST nodes to macros. No
conformance have been migrated yet.
**Motivation**:
Derived conformances (e.g. `Equatable`, `Hashable`, `Codable`, ...) are
currently implemented as a special case in the compiler, producing
synthetic AST nodes directly. Migrating this to macros will hopefully
unify the code path with the existing macro expansion infrastructure,
make conformance synthesis easier to extend and test as well as reducing
the amount of special cases in the compiler.
**Changes**:
- New experimental feature flag `DeriveConformancesViaMacros`:
Introduces the flag that will eventually gate the new derived
conformance code paths. It does not control any behaviour for the moment
as none have been migrated yet but this enables future changes to be
built incrementally.
- New GeneratedSourceInfo and SourceFile kinds `SyntheticMacro`:
Introduces new GSI and SourceFile kinds named `SyntheticMacro` to
represent macros synthesized by the compiler. Since macros need a real
buffer to expand, this is the kind of source file and GSI associated
with those buffers.
- Conformance derivation via macros API:
Introduces the `deriveRequirementViaMacro` function that produces the
required witness via macro expansion.
See https://github.com/swiftlang/llvm-project/pull/13124 for
llvm-related changes.
**Next steps**:
- Macros do not contain any semantic information, especially regarding
types. Therefore it is necessary to provide them with type information
as an argument so they can eventually derive the conformances. A
separate PR is being created to generate this type information as
strings containing swift-parsable code for easy parsing on the macro
end.
- Implement derived conformance synthesis for individual protocols using
the new infrastructure, like `Equatable` or `Hashable` for starters.
- Wire the experimental flag to gate the new path once an implementation
exists
---------
Co-authored-by: Hamish Knight <hamish_knight@apple.com>
Otherwise the "nonisolated nonsending by default" mode blows up as
distributed thunk signatures dont match expectations.
This undoes the fix from https://github.com/swiftlang/swift/pull/83940
and applies the fix on the synthesis side of the distributed thunks,
such that they are @concurrent always -- which keeps their old semantics
basically, regardless of what "default" mode we have.
the new NonisolatedNonsendingByDefault upcoming feature breaks remote
calls in distributed actors, because the expected isolation doesn't
match and the runtime swift_distributed_execute_target_resume will
crash.
This is a short term fix to unblock adopters, however preferably we
should mark the thunks as nonisolated(nonsending), though that seems to
be more involved.
resolves rdar://159247975
The following warning was being emitted by newer versions of clang:
```
comparisons like 'X<=Y<=Z' don't have their mathematical meaning [-Wparentheses]
```
This code needs to be reworked to ensure that the conditions that are meant to
be asserted are true.
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.
Protocol conformances have a handful attributes that can apply to them
directly, including @unchecked (for Sendable), @preconcurrency, and
@retroactive. Generalize this into an option set that we carry around,
so it's a bit easier to add them, as well as reworking the
serialization logic to deal with an arbitrary number of such options.
Use this generality to add support for @unsafe conformances, which are
needed when unsafe witnesses are used to conform to safe requirements.
Implement general support for @unsafe conformances, including
producing a single diagnostic per missing @unsafe that provides a
Fix-It and collects together all of the unsafe witnesses as notes.
Some requirement machine work
Rename requirement to Value
Rename more things to Value
Fix integer checking for requirement
some docs and parser changes
Minor fixes
A bunch of synthesis code was getting this wrong
and setting an interface type for a TypedPattern.
Assert that we have a contextual type, and update
some synthesis logic.
This is in order to avoid errors in complete concurrency checking mnode
in distributed funcs, or rather their thunks, as there is isolation
boundary crossing happening when we pass a value to a distributed func.
This is because as we do this, we pass it to a nonisolated thunk:
```
nonisolated func THUNK(param: Thing) {
if remote {
...
} else {
await self.realFunc(param)
}
}
```
So what happens here is that the Thing would become isolated to the
task and we get a bad isolation crossing as we pass it along to the
"real func".
Sending values into the distributed thunk is the right thing to do to
resolve this problem: `nonisolated func THUNK(param: sending Thing) {}`
Resolves rdar://126577527
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
Test shadowed variable of same type
Fully type check caller side macro expansion
Skip macro default arg caller side expr at decl primary
Test macro expand more complex expressions
Set synthesized expression as implicit
Add test case for with argument, not compiling currently
Test with swiftinterface
Always use the string representation of the default argument
Now works across module boundary
Check works for multiple files
Make default argument expression work in single file
Use expected-error
Disallow expression macro as default argument
Using as a sub expression in default argument still allowed as expression macros behave the same as built-in magic literals