This PR changes the casting machinery to avoid casting `__SwiftValue` boxes
directly. This forces the caster to instead unwrap `__SwiftValue` boxes and
retry with the inner content. This results in boxed values being cast like the
inner content.
This fixes the behavior in situations like the following:
```
let t = ...
let s = t as Any as! AnyObject
// `s` is now a `__SwiftValue` box
// Next line should be true iff t conforms to NSCopying
// Prior to this change, it always succeeds
s is NSCopying
```
After this change, the above cast succeeds only if `t` actually
conforms to `NSCopying`.
This is a follow-on to PR#37683.
Related to: SR-14635
It appears that LLVM 15 changed the ABI for _Float16 on x86-64 such that
values are now passed in `xmm0` instead of using integer registers.
Also enable this code for Linux.
rdar://104134160
It turns out that we can just use the Float16 to Float32 conversion and
let the compiler turn that into a long double for us, which means we
can take advantage of the F16C CPU instructions if they're present as well.
rdar://104134160
We crash in ResolveAsSymbolicReference::operator() when a symbolic reference targets a missing symbol. We usually have very little information about what was missing when this happens. Instead of crashing, explicitly check for NULL and fatal error in that case, including information about the location of the symbolic reference that it came from.
`SWIFT_RUNTIME_STDLIB_INTERNAL` does `extern "C"`, so we can't put these
in a namespace and have to use a C-style prefix instead.
Also slightly rearrange the code in `CommandLine.cpp`.
rdar://103397975
Instead of triggering a fatal error on failure, return `nullptr` and
let the caller decide what to do about it. The CommandLine code should
trigger a fatal error, of course.
rdar://103397975
In various places we need to call the Windows API, and because Swift uses UTF-8
for its string representation, we can’t call the ANSI API functions (because the
code page used for the ANSI functions varies depending on the system locale
setting). Instead, we need to use the wide character APIs.
This means that we need to convert UTF-8 to wide character and vice-versa in
various places in the runtime.
rdar://103397975
If the replaced symbol goes away in the original library, the
replacement key in the replacement descriptor will be null. Handle this
by ignoring the replacement entry rather than crashing.
rdar://103307821
When deallocating a class instance, we check the retain count of the instance and error if it's greater than 1.
Self is allowed to be temporarily passed to other code from deinit, but there's no way to extend the lifetime of the object. Retaining it no longer extensd the lifetime. If self escapes from deinit, the result is a dangling pointer and eventual crash.
Instead of crashing randomly due to a dangling pointer, crash deliberately when destroying an object that has escaped.
rdar://93848484
