something other than a declaration.
The validation code already diagnosed all sorts of invalid declarations, but
it was ignoring AST nodes that aren't declarations at all.
Provide member macros with similar information about conformances to
what extension macros receive, allowing member macros to document
which conformances they care about (e.g., Decodable) and then
receiving the list of conformances that aren't already available for
the type in question. For example, a macro such as
@attached(member, conformances: Decodable, Encodable, names:
named(init(from:), encode(to:)))
macro Codable() = ...
Expanded on a type that is not already Decodable/Encodable would be
provided with Decodable and Encodable (via the new
`missingConformancesTo:` argument to the macro implementation) when
the type itself does not conform to those types.
Member macros still cannot produce conformances, so this is likely to
be used in conjunction with extension macros most of the time. The
extension macro declares the conformance, and can also declare any
members that shouldn't be part of the primary type definition---such
as initializers that shouldn't suppress the memberwise initializer. On
the other hand, the member macro will need to define any members that
must be in the primary definition, such as required initializers,
members that must be overridable by subclasses, and stored properties.
Codable synthesis is an example that benefits from member macros with
conformances, because for classes it wants to introduce a required
initializer for decoding and an overridable encode operation, and
these must be members of the nominal type itself. Specifically, the
`Codable` macro above is likely to have two attached member roles:
@attached(member, conformances: Decodable, Encodable, names:
named(init(from:), encode(to:)))
@attached(extension, conformances: Decodable, Encodable, names:
named(init(from:), encode(to:)))
macro Codable() = ...
where the "extension" role is responsible for defining the conformance
(always), and the "member" creates the appropriate members for classes
(`init` vs. `required init`).
Tracked by rdar://112532829.
Move out-of-place SingleValueStmtExpr checking into
`performSyntacticExprDiagnostics`, to ensure we
catch all expressions. Previously we did the walk
as a part of Decl-based MiscDiagnostics, but it
turns out that can miss expressions in property
initializers, subscript default arguments, and
custom attrs.
This does mean that we'll now no longer diagnose
out-of-place if/switch exprs if the expression
didn't type-check, but that's consistent with the
rest of MiscDiagnostics, and I don't think it will
be a major issue in practice. We probably ought to
consider moving this checking into PreCheckExpr,
but that would require first separating out
SequenceExpr folding, which has other consequences,
and so I'm leaving as future work for now.
In any nominal declaration or extension thereof that is produced by a
macro expansion, make sure we perform qualified name lookup when
resolving operators so that we're guaranteed to find the
macro-introduced operators. Otherwise, expanding a macro that defines
a new type with conformances involving operators doesn't work.
Fixes rdar://114257019,
Previously both `AreAllStoredPropertiesDefaultInitableRequest`
and `HasMemberwiseInitRequest` checked only "current" properties
of the type but macro expansions can add new stored and/or
init accessor properties that affect this logic so we need to
make sure that macro expansions happen and new properties are
accounted for.
Note that the original idea was to use `getStoredProperties()`
but that runs into multiple circularity issues related to lazy
properties.
Resolves: rdar://112153201
Pre-macro-expansion conformances are introduced at the point where an
attached extension macro is attached to a particular nominal type, and
can imply other conformances. Once the macro is expanded, they are
expected to be replaced by the real conformance from the extension
produced by the macro. This includes any other conformances that are
implied by that conformances. Ensure that the real conformance---and
every conformances it implies---are considered "better" than the
pre-expansion conformances.
Fixes a bug where we would pick the wrong (pre-expansion)
conformances, which would then fail to get fully type-checked prior to
serialization. This could accept invalid code that then crashed the
compiler, as in rdar://112916159.
The checking of the accessors generated by a macro against the
documented set of accessors for the macro is slightly too strict and
produces misleading error messages. Make the check slightly looser in
the case where an observer-producing macro (such as
`@ObservationIgnored`) is applied to a computed property. Here, we
would diagnose that the observer did not in fact produce any
observers, even though it couldn't have: computed properties don't get
observers. Remove the diagnostic in this case.
While here, add some tests and improve the wording of diagnostics a
bit.
Fixes rdar://113710199.
Fix two inter-related issues with extension macros that provide
conformances to a protocol, the combined effect of which is that one
cannot meaningfully provide extension macros that implement
conformances to a protocol like Equatable or Hashable that also
supports auto-synthesis.
The first issue involves name lookup of operators provided by macro
expansions. The logic for performing qualified lookup in addition to
unqualified lookup (for operators) did not account for extension
macros in the same manner as it did for member macros, so we would not
find a macro-produced operator (such as operator==) in witness
matching.
The second issue is more fundamental, which is that the conformance
lookup table would create `NormalProtocolConformance` instances for
pre-macro-expansion conformance entries, even though these should
always have been superseded by explicit conformances within the macro
expansion buffers. The end result is that we could end up with two
`NormalProtocolConformance` records for the same conformance. Some
code was taught to ignore the pre-expansion placeholder conformances,
other code was not. Instead, we now refuse to create a
`NormalProtocolConformance` for the pre-expansion entries, and remove
all of the special-case checks for this, so we always using the
superseding explicit conformances produced by the macro expansions (or
error if the macros don't produce them).
Fixes rdar://113994346 / https://github.com/apple/swift/issues/66348
If an accessor macro is placed on a computed property, then opts not to
produce a getter/setter, we would produce an error because the macro
didn't make the computed property... computed. Fix that; it's already
computed, and it's fine not to add accessors.
Fixes rdar://111586568.
stated in the original source.
If an extension macro can introduce protocol conformances, macro expansion
will check which of those protocols already have a stated conformance in the
original source. The protocols that don't will be passed as arguments to
extension macro expansion, indicating to the macro that it should only add
conformances to those protocols.
* Don't invalidate the lookup cache in 'getOrCreateSynthesizedFile()'
Adding a synthesized file itself doesn't introduce any decls. Instead,
we should invalidate the right after the actual declrations are added
in the file
* Remove 'SourceLookupCache::invalidate()' method. It was just used
right before the destruction. It was just not necessary
* Include auxiliary decls in 'SourceLookupCache::lookupVisibleDecls()'
Previously, global symbol completion didn't include decls synthesized
by peer macros or freestanding decl macros
* Include "auxiliary decls" in visible member lookup, and visible local
decl lookup
* Hide macro unique names
rdar://110535113
The compiler knows (from a macro declaration) what freestanding macro
role a macro implementation is expected to implement. Pass that through
to the macro expansion code itself, rather than guessing based on the
protocol conformances of the implementation type. We already use this
approach with attached macros, so this is more of the same.
Eliminates a crash and improves diagnostics when the freestanding macro
role and its implementation are out of sync, fixing rdar://110418969.
Some places want to do in-order walks of MacroExpansionDecls, but still
visit auxiliary declarations. Rather than force them to specifically
filter out declarations from the MacroExpansionDecl, add a parameter to
visitAuxiliaryDecls to skip them.
Operators introduced by member macros are not getting found by global
operator lookup. This is technically a bug, but due to the potential
cost of having to expand macros on/in types just to find operators,
for now we're just going to document here that it doesn't work and
reconsider the semantics.
Well, this is fun. Due to the use of the module-scope lookup table to
find operators, we need to carefully filter out any macro-introduced
declarations that *aren't* operators when forming the module-scope
lookup table. Otherwise, we can find macro-introduced static entities
within types... from completely unrelated scopes.
Fixes rdar://109219036.
`TypeChecker::checkExistentialTypes` has decl-specific logic and backs out without invoking `ExistentialTypeVisitor` on `TypeDecl`s, but `MacroExpansionDecl` isn't a type decl and would fall into `ExistentialTypeVisitor` which will visit its expansion. The caller of `checkExistentialTypes` already visits auxiliary decls, so here we should only visit arguments and generic arguments of a macro.
Fixes a case where a declaration macro produces a type that conforms to a PAT. We now also run existential diagnostics on generic arguments on a `MacroExpansionDecl` that was previously not handled.
Note: I tried bailing out in `walkToDeclPre` but we should really visit macro arguments and generic arguments. Not walking expansions in `ExistentialTypeVisitor` is also not the right fix because we need to be able to visit macro expansions in arguments.
rdar://109779928
Calling `getInnermostDeclContext()->getParentSourceFile()` on a macro-produced decl does not seem to be a reliable way to obtain the macro expansion source file, because `PatternBindingDecl` is not a `DeclContext` and `getInnermostDeclContext()` falls back outside the macro expansion file. This patch switches to using `getSourceFileContainingLocation` when possible.
Resolves rdar://109376568.
