averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-14 20:36:38 +01:00
Code Issues Packages Projects Releases Wiki Activity

Revert #68952 [Casting] Make more casts look inside __SwiftValue

Browse Source 
Turns out that our Obj-C bridging relies on this inconsistent behavior,
so it can quite likely never be actually fixed.
This commit is contained in:
Tim Kientzle
2024-01-17 18:14:57 -08:00
parent 96ee57b00b
commit 4ea5ed1309
2 changed files with 12 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
stdlib/public/runtime/SwiftObject.mm
View File

@@ -1171,25 +1171,6 @@ swift_dynamicCastObjCClassImpl(const void *object,
if (object == nullptr)
return nullptr;
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wreceiver-forward-class"
if ([id_const_cast(object) isKindOfClass:[__SwiftValue class]]) {
#pragma clang diagnostic pop
// Source is a `__SwiftValue` container
// Unwrap, then use the most general casting machine to do the heavy lifting
auto typeValue = getValueFromSwiftValue(reinterpret_cast<__SwiftValue *>(object));
const void *result = nullptr;
if (swift_dynamicCast(reinterpret_cast<OpaqueValue *>(&result),
const_cast<OpaqueValue *>(typeValue.second),
typeValue.first,
targetType,
DynamicCastFlags::TakeOnSuccess)) {
return result;
} else {
return nullptr;
}
}
if ([id_const_cast(object) isKindOfClass:class_const_cast(targetType)]) {
return object;
}

13
test/Casting/Casts.swift
View File

@@ -1065,13 +1065,24 @@ CastsTests.test("Don't put AnyHashable inside AnyObject") {
}
#if _runtime(_ObjC)
CastsTests.test("__SwiftValue should not be obvious to `is`") {
// We currently (as of Jan 2024) bridge NSSet to Swift with `x as!
// Set<NSObject>`, which in turn demands that __SwiftValue successfully cast to
// NSObject.
// So this nonsensical behavior can probably never be fixed.
// (It's nonsense because it implies that every Swift object is derived
// from NSObject.) See PR #68952 for an early attempt to change it which
// had to be reverted.
CastsTests.test("__SwiftValue should not be obvious to `is`")
.xfail(.always("Probably can never be fixed"))
.code {
struct S {}
let s = S() as AnyObject
expectFalse(s is NSObject)
}
#endif
// See above for reasons why this might need to remain broken forever,
// though I do have some hope for it.
CastsTests.test("type(of:) should look through __SwiftValue")
.xfail(.always("Known to be broken"))
.code {