This attribute can be attached to a noncopyable struct to specify that its
storage is raw, meaning the type definition is (with some limitations)
able to do as it pleases with the storage. This provides a basis for
implementing types for things like atomics, locks, and data structures
that use inline storage to store conditionally-initialized values.
The example in `test/Prototypes/UnfairLock.swift` demonstrates the use
of a raw layout type to wrap Darwin's `os_unfair_lock` APIs, allowing
a lock value to be stored inside of classes or other types without
needing a separate allocation, and using the borrow model to enforce
safe access to lock-guarded storage.
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.
The excessive escaping of `init` in macro role attributes was a
workaround paired with https://github.com/apple/swift/pull/65442 to
smooth things over when working across Swift compiler versions.
However, it's causing problems for init accessors, so stop escaping.
Fixes rdar://111190084.
Add a special request that validates all of the property names
referenced by `initialized` and `accesses`, does the lookup and
returns underlying `VarDecl`s. This would also be used by DI.
Direct lookup relied in primary file checking to have filled in the
protocol type stored in the ImplementsAttr. This was already wrong
with multi-file test cases in non-WMO mode, and crashed in the
ASTPrinter if printing a declaration in a non-primary file.
I don't have a standalone test case that is independent of my
upcoming ASTPrinter changes, but this is a nice cleanup regardless.
* Add @_used and @_section attributes for global variables and top-level functions
This adds:
- @_used attribute that flags as a global variable or a top-level function as
"do not dead-strip" via llvm.used, roughly the equivalent of
__attribute__((used)) in C/C++.
- @_section("...") attribute that places a global variable or a top-level
function into a section with that name, roughly the equivalent of
__attribute__((section("..."))) in C/C++.
* Parse `#<identifier>` attribute list as a `MacroExpansionDecl`
regardless of the position
* Diagnose whitespaces between `#` and the macro name.
* Correctly attach attributes to `MacroExpansionDecl`
* Fix `OrigDeclAttributes` to handle modifiers (use `getLocation()`
instead of `AtLoc`.)
Type checking is a TODO
rdar://107386648
Older compilers can't parse `name(init)`. Restore the call to
`escapeKeywordInContext()` to ensure special names get escaped.
Resolves rdar://108806697
Parse compound and special names in the macro role attributes
(`@freestanding` and `@attached`). This allows both compound names and
initializers, e.g., `init(coding:)`.
Fixes rdar://107967344.
This method was misleading. The majority of callers (all but one!) don't want
to unconditionally treat all locations in any macro expansion buffer the
same way, because the code also must handle nested macro expansions. There
is one part of SourceKit (and possibly others) that really do want to ignore
all macro expansions, but those can be handled within SourceKit / IDE code,
because I don't believe this utility is useful in the frontend.
`decl->getOriginalAttrs()->getAttributes<...>` isn't safe in the current
API. Update `OrigDeclAttributes` to filter its attributes to the
original ones on demand, rather than filtering and storing a vector
inline.
Resolves rdar://107342658.
Various requests expect to be walking over the current source file.
While we could add checks to all these to skip decls outside of the
current buffer, it's a little nicer to handle this during the walk
instead.
Allow ignoring nodes that are from macro expansions and add that flag to
the various walks that expect it.
Also add a new `getOriginalAttrs` that filters out attributes in
generated source.
The macro role argument presented an opportunity for callers to accidentally
invoke this request twice for the same macro with slightly different macro
roles passed in, which resulted in re-typechecking the macro arguments.
Instead, derive the corresponding macro roles from the macro reference syntax.
- Use the name lookup table instead of adding members from a macro expansion to the parent decl context.
- Require declaration macros to specify introduced names and used the declared names to guide macro expansions lazily.
Rename `ResolveAttachedMacroRequest` to `ResolveMacroRequest` and make use of the request in freestanding declaration macro type checking. Add support for type-checking generic arguments on `MacroExpansionDecl`.
The attached and freestanding macro attributes use the same parsing
logic and representation, so generalize the "attached" attribute into
a more general "macro role" attribute.
Describe attached macros with the `@attached` attribute, providing the
macro role and affected names as arguments to the macro. The form of
this macro will remain the same as it gains other kinds of attached
macro roles beyond "accessor".
Remove the "accessors" role from `@declaration`, which will be going
away.
Add support for freestanding declaration macros.
- Parse `@declaration` attribute.
- Type check and expand `MacroExpansionDecl`.
Known issues:
- Generic macros are not yet handled.
- Expansion does not work when the parent decl context is `BraceStmt`. Need to parse freestanding declaration macro expansions in `BraceStmt` as `MacroExpansionDecl`, and add expanded decls to name lookup.
