This attribute forces programmers to acknowledge every
copy that is required to happen in the body of the
function. Only those copies that make sense according
to Swift's ownership rules should be "required".
The way this is implemented as of now is to flag each
non-explicit copy in a function, coming from SILGen, as
an error through PerformanceDiagnostics.
Based on what I see from OwnershipModelEliminator,
`%x = load [copy] %y` can turn into a plain load
followed by a retain of the loaded value.
See `NonTrivialLoadableTypeLowering::emitLoad`
When storing a closure with type `() throws(any Error) -> ()` as
a fully opaque error, we want to leave it unchanged, instead of
re-abstracting it to throw the error indirectly. Thus, we had
a special carveout here.
However, the carveout was too broad, because if the thrown error
type contained type parameters, the resulting AbstractionPattern
was invalid.
While fixing this I realized this entire hack is unsound in some
cases, if you view the same value as a `() throws(U) -> ()` vs
an `() -> throws(any Error) -> ()`.
Perhaps we should always box the thrown error when maximally
abstracting a closure, but that would also be an ABI break.
- Fixes https://github.com/swiftlang/swift/issues/84051
It's permitted for a `witness_method` instruction to have multiple
type-dependent operands. This can happen when for example when one
local archetype is defined in terms of another.
rdar://159211502
ResultConvention::Guaranteed will be used by borrow accessors when the storage type can be returned by value.
ResultConvention::GuaranteedAddress will be used by mutate accessors and borrow accessors when the storage type
cannot be returned by value.
As with SIL functions, track the parent module where a SIL global
variable was originally defined so that we can determine whether we
are outside of its original module for linkage purposes. Use this to
make sure we emit via a weak definition when emitting to a module
other than the originating module.
Fixes rdar://160153163.
Delay the emission of SIL global variables that aren't externally
visible until they are actually used. This is the same lazy emission
approach that we use for a number of other entities, such as SIL
functions.
Part of rdar://158363967.
* move some Cloner utilities from ContextCommon.swift directly into Cloner.swift
* add an `cloneRecursively` overload which doesn't require the `customGetCloned` closure argument
* some small cleanups
Introduce an experimental feature DeferredCodeGen, that defers the
generation of LLVM IR (and therefore object code) for all entities
within an Embedded Swift module unless they have explicitly requested
to not be emitted into the client (e.g., with
`@_neverEmitIntoClient`).
This feature is meant to generalize and subsume
-emit-empty-object-file, relying on lazy emission of entities rather
than abruptly ending the compilation pipeline before emitting any IR.
Part of rdar://158363967.
* When constructing instructions which have substitution maps: initialize those with the canonical SubstitutionMap
* Also initialize SILFunction::ForwardingSubMap with the canonical one
Non-canonical substitution maps may prevent generic specializations.
This fixes a problem in Embedded Swift where an error is given because a function cannot be specialized, although it should.
https://github.com/swiftlang/swift/issues/83895
rdar://159065157
