Beside supporting OSSA, this change significantly simplifies the pass.
The main change is that instead of starting at a closure (e.g. `partial_apply`) and finding all call sites, we now start at a call site and look for closures for all arguments. This makes a lot of things much simpler, e.g. not so many intermediate data structures are required to track all the states.
I needed to remove the 3 unit tests because the things those tests were testing are not there anymore. However, the pass is tested with a lot of sil tests (and I added quite a few), which should give good test coverage.
The old ClosureSpecializer pass is still kept in place, because at that point in the pipeline we don't have OSSA, yet. Once we have that, we can replace the old pass withe the new one.
However, the autodiff closure specializer already runs in the OSSA pipeline and there the new changes take effect.
Lifetime diagnostics may report an error within an implicit initializer or
accessor. The source location is misleading in these cases and causes much
consternation.
Storing a trivial enum case in a non-trivial enum must be treated like a non-trivial init or assign, e.g.
```
%1 = enum $Optional<String>, #Optional.none!enumelt
store %1 to [trivial] %0 // <- cannot delete this store!
store %2 to [assign] %0
```
The intent for `@inline(always)` is to act as an optimization control.
The user can rely on inlining to happen or the compiler will emit an error
message.
Because function values can be dynamic (closures, protocol/class lookup)
this guarantee can only be upheld for direct function references.
In cases where the optimizer can resolve dynamic function values the
attribute shall be respected.
rdar://148608854
We cannot do this because we don't know where to insert the compensating release after the propagated `partial_apply`.
A required `strong_retain` may have been moved over the `partial_apply`.
Then we would release the keypath too early.
Fixes a mis-compile
rdar://161321614
When the source of a lifetime dependency is a stack-allocated address, extend
the stack allocation to cover all dependent uses.
This avoids miscompilations for "addressable" dependencies which arise in code
built with -enable-experimental-feature AddressableTypes or
AddressableParameters. It is always an error for SILGen to emit the alloc_stack
in such cases. Nonetheless, we want to handle these unexpected cases gracefully
in SIL as a diagnostic error rather than allowing a miscompile.
Fixes rdar://159680262 ([nonescapable] diagnose dependence on a
temporary copy of a global array)
(old name: CapturePropagation)
The pass is now rewritten in swift which makes the code smaller and simpler.
Compared to the old pass it has two improvements:
* It can constant propagate whole structs (and not only builtin literals). This is important for propagating "real" Swift constants which have a struct type of e.g. `Int`.
* It constant propagates keypaths even if there are other non-constant closure captures which are not propagated. This is something the old pass didn't do.
rdar://151185177
Once we have promoted the box to stack, access violations can be detected statically by the DiagnoseStaticExclusivity pass (which runs after MandatoryAllocBoxToStack).
Therefore we can convert dynamic accesses to static accesses.
rdar://157458037
If exclusivity is checked for the alloc_stack we must not replace it with the copy-destination.
If the copy-destination is also in an access-scope this would result in an exclusivity violation which was not there before.
Fixes a miscompile which results in a wrong exclusivity violation error at runtime.
https://github.com/swiftlang/swift/issues/83924
rdar://159220436
