For those unfamiliar, this map is a vector of pairs that we stable sort by the
key when we "freeze" it so we can run map operations upon the keys. This allows
one to accumulate into the multi-map and then once one has finished
accumulating, perform these map operations.
While doing some work in the move checker, I thought I would need the ability to
incrementally update a multi-map by appending more entires. Due to the design,
supporting this is as simple as unfreezing the map. This results in one being no
longer able to run map operations without hitting an assert. When one freezes
again, the stable sort will put the new entries in the appropriate place in the
already sorted initial part of the array.
Turns out I didn't need this, but seemed useful, so I am upstreaming it.
A lot of existing regression tests rely on there
being some form of move-only classes, despite
them being something that will not be available
to users (and not complete).
This change introduces a `MoveOnlyClasses`
experimental feature so that those tests don't
need to be fully rewritten just yet. You need to
include `-enable-experimental-feature MoveOnlyClasses` along with
`-enable-experimental-move-only` to get move-only classes.
The SwiftDiagnostics module within swift-syntax has a diagnostic
pretty-printer that does a nice rendering of the source code with
diagnostics placed inside gaps between the code lines.
Introduce another `-diagnostic-style` argument, `swift-syntax`,
to bridge from the pretty-printed C++ diagnostics over to the
swift-syntax diagnostics engine.
Accessor macros are attached macros (written with attribute syntax)
that can generate accessors for a property or subscript. Recognize
custom attributes that are accessor macros when written on a storage
declaration, and expand those macros.
This is very much a work in progress, and the result of the expansion
isn't yet parsed or wired into the AST.
* Basic/type_traits: use `__is_identifier` for some feature checks
When building on Alpine with Musl `__has_feature(is_trivially_constructible)` does not work, even though `__is_trivially_constructible` is defined and `__has_trivial_constructor` is deprecated. Same for `__is_trivially_destructible` and `__has_trivial_destructor` respectively.
* Basic/type_traits: use `__has_feature` or `__has_keyword`
That potentially makes these checks more future-proof in case more edge cases are introduced on different platforms.
When building on Alpine with Musl `__has_feature(is_trivially_constructible)` does not work, even though `__is_trivially_constructible` is defined and `__has_trivial_constructor` is deprecated. Same for `__is_trivially_destructible` and `__has_trivial_destructor` respectively.
For some reason LLVM doesn't provide this. I have written a few versions of this
in the Swift codebase. Makes sense to factor it out before I make another one.
When emitting a diagnostic that references a declaration that does not
itself have a source location (e.g., because it was synthesized or
deserialized), the diagnostics engine pretty-prints the declaration
into a buffer so it can provide caret diagnostics pointing to that
declaration.
Start marking those buffers as "generated source buffers", so that we
emit their contents into serialized diagnostics files. This will allow
tools that make use of serialized diagnostics to also show caret
information.
When a declaration has a structural opaque return type like:
func foo() -> Bar<some P>
then to mangle that return type `Bar<some P>`, we have to mangle the `some P`
part by referencing its defining declaration `foo()`, which in turn includes
its return type `Bar<some P>` again (this time using a special mangling for
`some P` that prevents infinite recursion). Since we mangle `Bar<some P>`
once as part of mangling the declaration, and we register substitutions for
bound generic types when they're complete, we end up registering the
substitution for `Bar<some P>` twice, once as the return type of the
declaration name, and again as the actual type. This would be fine, except
that the mangler doesn't check for key collisions, and it picks
substitution indexes based on the number of entries in its hash map, so
the duplicated substitution ends up corrupting the substitution sequence,
causing the mangler to produce an invalid mangled name.
Fixing that exposes us to another problem in the remangler: the AST
mangler keys substitutions by type identity, but the remangler
uses the value of the demangled nodes to recognize substitutions.
The mangling for `Bar<current declaration's opaque return type>` can
appear multiple times in a demangled tree, but referring to different
declarations' opaque return types, and the remangler would reconstruct
an incorrect mangled name when this happens. To avoid this, change the
way the demangler represents `OpaqueReturnType` nodes so that they
contain a backreference to the declaration they represent, so that
substitutions involving different declarations' opaque return types
don't get confused.
Each macro expansion buffer was getting parsed twice: once by
ParseSourceFileRequest (which is used by unqualified name lookup) and
once to parse the expression when type-checking the expanded macro.
This meant that the same code had two ASTs. Hilarity ensures.
Stop directly invoking the parser on macro-expanded code. Instead, go
through ParseSourceFileRequest *as is always the right way*, and dig
out the expression we want.
