Previously, the initializer expressions of lazy vars would only be marked as
subsumed when the getter body for the var was synthesized. This didn't work
with `-experimental-lazy-typechecking` since accessor synthesis was not
guaranteed to happen. Consequently, SILGen would emit the initializer even
though it was already subsumed and then assert/crash since the init had also
not been checked and contextualized. Now lazy var inits are marked subsumed in
the request creating storage.
Resolves rdar://118421753
As a follow up to https://github.com/apple/swift/pull/69841, clarify the
possible states that initializer expression of a pattern can be in. The
possible states are not checked, checked, and "checked and contextualized"
(which is the new state that was introduced and requestified in the previous
PR). This refactoring encodes the states more explicitly and renames a few
compiler APIs to better align with the new naming. NFC.
Allow initializer expressions to be emitted during SILGen when
`-experimental-lazy-typecheck` is specified by introducing a new request that
fully typechecks the init expressions of pattern binding declarations
on-demand.
There are still a few rough edges, like missing support for wrapped properties
and incomplete handling of subsumed initializers. Fixing these issues is not an
immediate priority because in the short term `-experimental-lazy-typecheck`
will always be accompanied by `-enable-library-evolution` and
`-experimental-skip-non-exportable-decls`. This means that only the
initializers of properties on `@frozen` types will need to be emitted and
property wrappers are not yet fully supported on properties belonging to
`@frozen` types.
Resolves rdar://117448868
When -experimental-skip-non-exportable-decls is specified, the SIL for the
initializers of stored properties is unneeded and should be skipped so long as
the property does not belong to a `@frozen` type.
Functions that are nested within other functions are not exportable to clients
since they cannot be called directly by clients. However, they need still to be
emitted during SILGen when -experimental-skip-non-exportable-decls is specified
so walk the decl context hierarchy when determining whether to skip emitting a
function.
Resolves rdar://117440503
I've renamed the method to `TypeDecl::isNoncopyable`, because the query
doesn't make sense for many other kinds of `ValueDecl`'s beyond the
`TypeDecl`'s. In fact, it looks like no one was relying on that anyway.
Thus, we now have a distinction where in Sema, you ask whether
a `Type` or `TypeDecl` is "Noncopyable". But within SIL, we still
preserve the notion of "move-only" since there is additionally the
move-only type wrapper for types that otherwise support copying.
Function bodies are skipped during typechecking when one of the
-experimental-skip-*-function-bodies flags is passed to the frontend. This was
implemented by setting the "body kind" of an `AbstractFunctionDecl` during decl
checking in `TypeCheckDeclPrimary`. This approach had a couple of issues:
- It is incompatible with skipping function bodies during lazy typechecking,
since the skipping is only evaluated during a phase of eager typechecking.
- It prevents skipped function bodies from being parsed on-demand ("skipped" is
a state that is distinct from "parsed", when they ought to be orthogonal).
This needlessly prevented complete module interfaces from being emitted with
-experimental-skip-all-function-bodies.
Storing the skipped status of a function separately from body kind and
requestifying the determination of whether to skip a function solves these
problems.
Resolves rdar://116020403
Moving the query implementation up to the AST library from SIL will allow
conveniences to be written on specific AST element classes. For instance, this
will allow `EnumDecl` to expose a convenience that enumerates element decls
that are available during lowering.
Also, improve naming and documentation for these queries.
This is a futile attempt to discourage future use of getType() by
giving it a "scary" name.
We want people to use getInterfaceType() like with the other decl kinds.
Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
Macro-generated extensions are hoisted to file scope, because extensions are
not valid in nested scopes. Callers of 'visitAuxiliaryDecls' assume that the
auxiliary decls are in the same decl context as the original, which is clearly
not the case for extensions, and it leads to issues like visiting extension at
the wrong time during SILGen. The extensions are already added to the top-level
decls, so we don't need to visit them as auxiliary decls, and we can type-check
macro-expanded decls at the end of visitation in TypeCheckDeclPrimary.
This source location will be used to determine whether to add a name lookup
option to exclude macro expansions when the name lookup request is constructed.
Currently, the source location argument is unused.
Some notes:
1. I put in both a swiftpm like test case and a library evolution test case. I
also updated the moveonly_deinit serialization swift test to show that we
actually serialize the deinit.
2. I changed when we emit the deinit table to only be when we have a type with
an actual value type destructor. Notably this doesn't include classes today so
as a side-effect, we no longer attempt to devirtualize moveonly class deinits.
This doesn't affect anything we are trying to actually do since we do not
support noncopyable classes today. With that in mind, I changed one test that
was showing that deinit devirtualization worked to use a struct with deinit
instead of a class.
rdar://109679168
When expanding a conformance macro, the generated extension decls are added to
the TopLevelDecls vector of the synthesized file unit to expose them to
sf->getSynthesizedFile()->getTopLevelDecls(). There are two problems with this:
1. These decls are also visited via visitAuxiliaryDecls() for the purpose of
type checking. This causes problems in code generation because the extensions
are visited separately, and because SIL and IRGen assume nested auxiliary decls
are members.
2. SILGen only emits top-level decls directly from the source file rather than its
synthesized file. Auxiliary decls are visited here, but this doesn't work for
nested conformance macros because the attached-to decl is not at the top-level,
so macro-generated conformances for nested types never emit their descriptor.
To fix this in the short term, visit top-level decls in the synthesized file that are
generated by conformance macros, and skip auxiliary extension decls when emitting type
members. This fix is narrowly scoped to only impact macros, but in the future this
warrants a more structural fix to better handle top-level decls in the synthesized file.
Previously, the location used for functions corresponding to @main was
just RegularLocation::getModuleLocation(). Make that more specific by
using the annotated type's location instead.
rdar://79508092
Allow freestanding macros to be used at top-level.
- Parse top-level `#…` as `MacroExpansionDecl` when we are not in scripting mode.
- Add macro expansion decls to the source lookup cache with name-driven lazy expansion. Not supporting arbitrary name yet.
- Experimental support for script mode and brace-level declaration macro expansions: When type-checking a `MacroExpansionExpr`, assign it a substitute `MacroExpansionDecl` if the macro reference resolves to a declaration macro. This doesn’t work quite fully yet and will be enabled in a future fix.
Always use `Decl::visitAuxiliaryDecls` to visit decls produced by macros, including peer macros and declaration macros. Use name-driven expansion for peer macros. Remove `MacroExpansionDecl::getRewritten()`.
Also make `ExpandMacroExpansionDeclRequest` cache the buffer ID (similar to other macros) instead of an array of decls.
Previously, typechecking and SILGen would treat a function body as fragile as long as the declaration had a `@backDeployed` attribute, regardless of the platform specified by the attribute. This was overly conservative since back deployed functions are only emitted into the client on specific platforms. Now a `@backDeployed` function can reference non-`public` declarations on the platforms it is resilient on:
```
@backDeployed(before: iOS 15)
public func foo() {
#if os(iOS)
// Fragile; this code may be emitted into the client.
#else
// Resilient; this code won't ever be exposed to clients.
#endif
}
```
Resolves rdar://105298520
Global peer macro expansions are not injected into the AST. Instead, they
are visited as "auxiliary declarations" when needed, such as in the decl
checker and during SILGen. This is the same mechanism used for local property
wrappers and local lazy variables.
