mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
Motivated by need for protocol-based dynamic dispatch, which hasn't been possible in Embedded Swift due to a full ban on existentials. This lifts that restriction but only for class-bound existentials: Class-bound existentials are already (even in desktop Swift) much more lightweight than full existentials, as they don't need type metadata, their containers are typically 2 words only (reference + wtable pointer), don't incur copies (only retains+releases). Included in this PR: [x] Non-generic class-bound existentials, executable tests for those. [x] Extension methods on protocols and using those from a class-bound existential. [x] RuntimeEffects now differentiate between Existential and ExistentialClassBound. [x] PerformanceDiagnostics don't flag ExistentialClassBound in Embedded Swift. [x] WTables are generated in IRGen when needed. Left for follow-up PRs: [ ] Generic classes support
36 lines
977 B
Swift
36 lines
977 B
Swift
// RUN: %target-swift-emit-ir -parse-as-library -module-name main -verify %s -enable-experimental-feature Embedded -wmo
|
|
|
|
// REQUIRES: swift_in_compiler
|
|
// REQUIRES: optimized_stdlib
|
|
// REQUIRES: OS=macosx || OS=linux-gnu
|
|
|
|
protocol ClassBound: AnyObject {
|
|
func foo()
|
|
}
|
|
|
|
protocol NotClassBound {
|
|
func foo()
|
|
}
|
|
|
|
class MyClass {}
|
|
extension MyClass: ClassBound, NotClassBound {
|
|
func foo() { print("MyClass.foo()") }
|
|
}
|
|
|
|
func test(existential: any ClassBound) {
|
|
existential.foo() // ok
|
|
}
|
|
|
|
func test(existential: any NotClassBound) {
|
|
existential.foo() // expected-error {{cannot use a value of protocol type in embedded Swift}}
|
|
// expected-note@+3 {{called from here}}
|
|
}
|
|
|
|
@main
|
|
struct Main {
|
|
static func main() {
|
|
test(existential: MyClass() as (any ClassBound)) // ok
|
|
test(existential: MyClass() as (any NotClassBound)) // expected-error {{cannot use a value of protocol type 'any NotClassBound' in embedded Swift}}
|
|
}
|
|
}
|