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SILGen: Fix generated vtable thunk when a final override is more visible than the base #25678

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Merged
merged 1 commit into from
Jun 22, 2019
Merged

SILGen: Fix generated vtable thunk when a final override is more visible than the base #25678

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5 changes: 3 additions & 2 deletions lib/SILGen/SILGenType.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -96,8 +96,9 @@ SILGenModule::emitVTableMethod(ClassDecl *theClass,
// If the base method is less visible than the derived method, we need
// a thunk.
bool baseLessVisibleThanDerived =
(derivedDecl->isEffectiveLinkageMoreVisibleThan(baseDecl) &&
!usesObjCDynamicDispatch);
(!usesObjCDynamicDispatch &&
!derivedDecl->isFinal() &&
derivedDecl->isEffectiveLinkageMoreVisibleThan(baseDecl));

// Determine the derived thunk type by lowering the derived type against the
// abstraction pattern of the base.
Expand Down
6 changes: 6 additions & 0 deletions test/Interpreter/Inputs/vtables_multifile_2.swift
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Expand Up @@ -13,6 +13,12 @@ open class Derived : Base {
}
}

public final class FinalDerived : Base {
public override func privateMethod() -> Int {
return super.privateMethod() + 1
}
}

public func callBaseMethod(_ b: Base) -> Int {
return b.privateMethod()
}
Expand Down
11 changes: 11 additions & 0 deletions test/Interpreter/vtables_multifile.swift
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Expand Up @@ -21,6 +21,12 @@ open class OtherDerived : Derived {
}
}

public final class OtherFinalDerived : Derived {
public override func privateMethod() -> Int {
return super.privateMethod() + 1
}
}

VTableTestSuite.test("Base") {
expectEqual(1, callBaseMethod(Base()))
}
Expand All @@ -35,4 +41,9 @@ VTableTestSuite.test("OtherDerived") {
expectEqual(3, callDerivedMethod(OtherDerived()))
}

VTableTestSuite.test("OtherFinalDerived") {
expectEqual(3, callBaseMethod(OtherFinalDerived()))
expectEqual(3, callDerivedMethod(OtherFinalDerived()))
}

runAllTests()
47 changes: 44 additions & 3 deletions test/SILGen/vtables_multifile.swift
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Expand Up @@ -34,6 +34,13 @@ open class MostDerived : MoreDerived {
open override func privateMethod4(_: Int) {}
}

public final class FinalDerived : Base<Int> {
internal override func privateMethod1() {}
internal override func privateMethod2(_: AnyObject?) {}
internal override func privateMethod3(_: Int?) {}
internal override func privateMethod4(_: Int) {}
}

// See Inputs/vtables_multifile_2.swift for overrides in a different file.
// See Inputs/vtables_multifile_3.swift for overrides in a different module.

Expand Down Expand Up @@ -127,7 +134,6 @@ open class MostDerived : MoreDerived {
// CHECK-NEXT: return [[RESULT]] : $()
// CHECK-NEXT: }

// vtable thunk for Derived.privateMethod2(_:) dispatching to MoreDerived.privateMethod2(_:)
// CHECK-LABEL: sil private [ossa] @$s17vtables_multifile11MoreDerivedC14privateMethod2yyyXlSgFAA0D0CADyyAEFTV : $@convention(method) (@guaranteed Optional<AnyObject>, @guaranteed MoreDerived) -> () {
// CHECK: bb0(%0 : @guaranteed $Optional<AnyObject>, %1 : @guaranteed $MoreDerived):
// CHECK-NEXT: [[METHOD:%.*]] = class_method %1 : $MoreDerived, #MoreDerived.privateMethod2!1 : (MoreDerived) -> (AnyObject?) -> (), $@convention(method) (@guaranteed Optional<AnyObject>, @guaranteed MoreDerived) -> ()
Expand All @@ -136,7 +142,6 @@ open class MostDerived : MoreDerived {
// CHECK-NEXT: return [[RESULT]] : $()
// CHECK-NEXT: }

// vtable thunk for Derived.privateMethod3(_:) dispatching to MoreDerived.privateMethod3(_:)
// CHECK-LABEL: il private [ossa] @$s17vtables_multifile11MoreDerivedC14privateMethod3yySiSgFAA0D0CADyyAEFTV : $@convention(method) (Optional<Int>, @guaranteed MoreDerived) -> () {
// CHECK: bb0(%0 : $Optional<Int>, %1 : @guaranteed $MoreDerived):
// CHECK-NEXT: [[METHOD:%.*]] = class_method %1 : $MoreDerived, #MoreDerived.privateMethod3!1 : (MoreDerived) -> (Int?) -> (), $@convention(method) (Optional<Int>, @guaranteed MoreDerived) -> ()
Expand All @@ -145,7 +150,6 @@ open class MostDerived : MoreDerived {
// CHECK-NEXT: return [[RESULT]] : $()
// CHECK-NEXT: }

// vtable thunk for Derived.privateMethod4(_:) dispatching to MoreDerived.privateMethod4(_:)
// CHECK-LABEL: sil private [ossa] @$s17vtables_multifile11MoreDerivedC14privateMethod4yySiFAA0D0CADyySiFTV : $@convention(method) (Int, @guaranteed MoreDerived) -> () {
// CHECK: bb0(%0 : $Int, %1 : @guaranteed $MoreDerived):
// CHECK-NEXT: [[METHOD:%.*]] = class_method %1 : $MoreDerived, #MoreDerived.privateMethod4!1 : (MoreDerived) -> (Int) -> (), $@convention(method) (Int, @guaranteed MoreDerived) -> ()
Expand All @@ -154,6 +158,30 @@ open class MostDerived : MoreDerived {
// CHECK-NEXT: return [[RESULT]] : $()
// CHECK-NEXT: }

// --
// Thunks for final overrides do not re-dispatch, even if the override is more
// visible.
// --

// CHECK-LABEL: sil private [ossa] @$s17vtables_multifile12FinalDerivedC14privateMethod3yySiSgFAA4BaseCAD33_63E5F2521A3C787F5F9EFD57FB9237EALLyySiFTV : $@convention(method) (Int, @guaranteed FinalDerived) -> () {
// CHECK: bb0(%0 : $Int, %1 : @guaranteed $FinalDerived):
// CHECK-NEXT: [[ARG:%.*]] = enum $Optional<Int>, #Optional.some!enumelt.1, %0 : $Int // user: %4
// CHECK: [[METHOD:%.*]] = function_ref @$s17vtables_multifile12FinalDerivedC14privateMethod3yySiSgF : $@convention(method) (Optional<Int>, @guaranteed FinalDerived) -> ()
// CHECK-NEXT: apply [[METHOD]]([[ARG]], %1) : $@convention(method) (Optional<Int>, @guaranteed FinalDerived) -> ()
// CHECK-NEXT: [[RESULT:%.*]] = tuple ()
// CHECK-NEXT: return [[RESULT]] : $()
// CHECK-NEXT: }

// CHECK-LABEL: sil private [ossa] @$s17vtables_multifile12FinalDerivedC14privateMethod4yySiFAA4BaseCAD33_63E5F2521A3C787F5F9EFD57FB9237EALLyyxFTV : $@convention(method) (@in_guaranteed Int, @guaranteed FinalDerived) -> () {
// CHECK: bb0(%0 : $*Int, %1 : @guaranteed $FinalDerived):
// CHECK-NEXT: [[ARG:%.*]] = load [trivial] %0 : $*Int
// CHECK: [[METHOD:%.*]] = function_ref @$s17vtables_multifile12FinalDerivedC14privateMethod4yySiF : $@convention(method) (Int, @guaranteed FinalDerived) -> ()
// CHECK-NEXT: [[RESULT:%.*]] = apply [[METHOD]]([[ARG]], %1) : $@convention(method) (Int, @guaranteed FinalDerived) -> ()
// CHECK-NEXT: [[RESULT:%.*]] = tuple ()
// CHECK-NEXT: return [[RESULT]] : $()
// CHECK-NEXT: }


// --
// VTable for Derived.
// --
Expand Down Expand Up @@ -212,3 +240,16 @@ open class MostDerived : MoreDerived {
// CHECK-NEXT: #MoreDerived.privateMethod4!1: (MoreDerived) -> (Int) -> () : @$s17vtables_multifile11MostDerivedC14privateMethod4yySiF [override] // MostDerived.privateMethod4(_:)
// CHECK-NEXT: #MostDerived.deinit!deallocator.1: @$s17vtables_multifile11MostDerivedCfD // MostDerived.__deallocating_deinit
// CHECK-NEXT: }

// --
// FinalDerived adds a final override; make sure we handle this correctly.
// --

// CHECK-LABEL: sil_vtable [serialized] FinalDerived {
// CHECK-NEXT: #Base.privateMethod1!1: <T> (Base<T>) -> () -> () : @$s17vtables_multifile12FinalDerivedC14privateMethod1yyF [override] // FinalDerived.privateMethod1()
// CHECK-NEXT: #Base.privateMethod2!1: <T> (Base<T>) -> (AnyObject) -> () : @$s17vtables_multifile12FinalDerivedC14privateMethod2yyyXlSgF [override] // FinalDerived.privateMethod2(_:)
// CHECK-NEXT: #Base.privateMethod3!1: <T> (Base<T>) -> (Int) -> () : @$s17vtables_multifile12FinalDerivedC14privateMethod3yySiSgFAA4BaseCAD33_63E5F2521A3C787F5F9EFD57FB9237EALLyySiFTV [override] // vtable thunk for Base.privateMethod3(_:) dispatching to FinalDerived.privateMethod3(_:)
// CHECK-NEXT: #Base.privateMethod4!1: <T> (Base<T>) -> (T) -> () : @$s17vtables_multifile12FinalDerivedC14privateMethod4yySiFAA4BaseCAD33_63E5F2521A3C787F5F9EFD57FB9237EALLyyxFTV [override] // vtable thunk for Base.privateMethod4(_:) dispatching to FinalDerived.privateMethod4(_:)
// CHECK-NEXT: #Base.init!allocator.1: <T> (Base<T>.Type) -> () -> Base<T> : @$s17vtables_multifile12FinalDerivedCACycfC [override] // FinalDerived.__allocating_init()
// CHECK-NEXT: #FinalDerived.deinit!deallocator.1: @$s17vtables_multifile12FinalDerivedCfD // FinalDerived.__deallocating_deinit
// CHECK-NEXT: }