Merge pull request swiftlang#20380 from slavapestov/protocol-superclass-fix

Sema: A protocol with a class constraint is a subtype of any protocols the class conforms to

Author: slavapestov

lib/Sema/TypeCheckProtocol.cpp

@@ -3956,9 +3956,8 @@ Optional<ProtocolConformanceRef> TypeChecker::containsProtocol(
 
     // First, if we have a superclass constraint, the class may conform
     // concretely.
-    if (layout.explicitSuperclass) {
-      if (auto result = conformsToProtocol(layout.explicitSuperclass, Proto,
-                                           DC, options)) {
+    if (auto superclass = layout.getSuperclass()) {
+      if (auto result = conformsToProtocol(superclass, Proto, DC, options)) {
         return result;
       }
     }
@@ -3972,15 +3971,6 @@ Optional<ProtocolConformanceRef> TypeChecker::containsProtocol(
       if (PD == Proto)
         return ProtocolConformanceRef(Proto);
 
-      // If the protocol has a superclass constraint, we might conform
-      // concretely.
-      if (auto superclass = PD->getSuperclass()) {
-        if (auto result = conformsToProtocol(superclass, Proto,
-                                             DC, options)) {
-          return result;
-        }
-      }
-
       // Now check refined protocols.
       if (PD->inheritsFrom(Proto))
         return ProtocolConformanceRef(Proto);

test/SILGen/protocol_with_superclass.swift

@@ -245,6 +245,30 @@ class ConformsToSillyDefault : ClassWithDefault<Int>, SillyDefault {}
 // CHECK: class_method %1 : $ClassWithDefault<Int>, #ClassWithDefault.makeT!1 : <T> (ClassWithDefault<T>) -> () -> T, $@convention(method) <τ_0_0> (@guaranteed ClassWithDefault<τ_0_0>) -> @out τ_0_0
 // CHECK: return
 
+class BaseClass : BaseProto {}
+
+protocol RefinedProto : BaseClass {}
+
+func takesBaseProtocol(_: BaseProto) {}
+
+func passesRefinedProtocol(_ r: RefinedProto) {
+  takesBaseProtocol(r)
+}
+
+// CHECK-LABEL: sil hidden @$s24protocol_with_superclass21passesRefinedProtocolyyAA0E5Proto_pF : $@convention(thin) (@guaranteed RefinedProto) -> ()
+// CHECK:     bb0(%0 : @guaranteed $RefinedProto):
+// CHECK:       [[OPENED:%.*]] = open_existential_ref %0 : $RefinedProto to $@opened("{{.*}}") RefinedProto
+// CHECK-NEXT:  [[BASE:%.*]] = alloc_stack $BaseProto
+// CHECK-NEXT:  [[BASE_PAYLOAD:%.*]] = init_existential_addr [[BASE]] : $*BaseProto, $@opened("{{.*}}") RefinedProto
+// CHECK-NEXT:  [[OPENED_COPY:%.*]] = copy_value [[OPENED]] : $@opened("{{.*}}") RefinedProto
+// CHECK-NEXT:  store [[OPENED_COPY]] to [init] [[BASE_PAYLOAD]] : $*@opened("{{.*}}") RefinedProto
+// CHECK:       [[FUNC:%.*]] = function_ref @$s24protocol_with_superclass17takesBaseProtocolyyAA0E5Proto_pF : $@convention(thin) (@in_guaranteed BaseProto) -> ()
+// CHECK-NEXT:  apply [[FUNC]]([[BASE]]) : $@convention(thin) (@in_guaranteed BaseProto) -> ()
+// CHECK-NEXT:  destroy_addr [[BASE]] : $*BaseProto
+// CHECK-NEXT:  dealloc_stack [[BASE]] : $*BaseProto
+// CHECK-NEXT:  [[RESULT:%.*]] = tuple ()
+// CHECK-NEXT:  return [[RESULT]] : $()
+
 // CHECK-LABEL: sil_witness_table hidden ConformsToSillyDefault: SillyDefault module protocol_with_superclass {
 // CHECK-NEXT: method #SillyDefault.makeT!1: <Self where Self : SillyDefault> (Self) -> () -> Int : @$s24protocol_with_superclass22ConformsToSillyDefaultCAA0fG0A2aDP5makeTSiyFTW
 // CHECK-NEXT: }

test/SILGen/protocol_with_superclass_where_clause.swift

@@ -245,6 +245,30 @@ class ConformsToSillyDefault : ClassWithDefault<Int>, SillyDefault {}
 // CHECK: class_method %1 : $ClassWithDefault<Int>, #ClassWithDefault.makeT!1 : <T> (ClassWithDefault<T>) -> () -> T, $@convention(method) <τ_0_0> (@guaranteed ClassWithDefault<τ_0_0>) -> @out τ_0_0
 // CHECK: return
 
+class BaseClass : BaseProto {}
+
+protocol RefinedProto where Self : BaseClass {}
+
+func takesBaseProtocol(_: BaseProto) {}
+
+func passesRefinedProtocol(_ r: RefinedProto) {
+  takesBaseProtocol(r)
+}
+
+// CHECK-LABEL: sil hidden @$s24protocol_with_superclass21passesRefinedProtocolyyAA0E5Proto_pF : $@convention(thin) (@guaranteed RefinedProto) -> ()
+// CHECK:     bb0(%0 : @guaranteed $RefinedProto):
+// CHECK:       [[OPENED:%.*]] = open_existential_ref %0 : $RefinedProto to $@opened("{{.*}}") RefinedProto
+// CHECK-NEXT:  [[BASE:%.*]] = alloc_stack $BaseProto
+// CHECK-NEXT:  [[BASE_PAYLOAD:%.*]] = init_existential_addr [[BASE]] : $*BaseProto, $@opened("{{.*}}") RefinedProto
+// CHECK-NEXT:  [[OPENED_COPY:%.*]] = copy_value [[OPENED]] : $@opened("{{.*}}") RefinedProto
+// CHECK-NEXT:  store [[OPENED_COPY]] to [init] [[BASE_PAYLOAD]] : $*@opened("{{.*}}") RefinedProto
+// CHECK:       [[FUNC:%.*]] = function_ref @$s24protocol_with_superclass17takesBaseProtocolyyAA0E5Proto_pF : $@convention(thin) (@in_guaranteed BaseProto) -> ()
+// CHECK-NEXT:  apply [[FUNC]]([[BASE]]) : $@convention(thin) (@in_guaranteed BaseProto) -> ()
+// CHECK-NEXT:  destroy_addr [[BASE]] : $*BaseProto
+// CHECK-NEXT:  dealloc_stack [[BASE]] : $*BaseProto
+// CHECK-NEXT:  [[RESULT:%.*]] = tuple ()
+// CHECK-NEXT:  return [[RESULT]] : $()
+
 // CHECK-LABEL: sil_witness_table hidden ConformsToSillyDefault: SillyDefault module protocol_with_superclass {
 // CHECK-NEXT: method #SillyDefault.makeT!1: <Self where Self : SillyDefault> (Self) -> () -> Int : @$s24protocol_with_superclass22ConformsToSillyDefaultCAA0fG0A2aDP5makeTSiyFTW
 // CHECK-NEXT: }

test/decl/protocol/protocol_with_superclass.swift

@@ -294,6 +294,12 @@ protocol RefinedProtocol : BaseClass {
   func takesT(_: T)
 }
 
+func takesBaseProtocol(_: BaseProtocol) {}
+
+func passesRefinedProtocol(_ r: RefinedProtocol) {
+  takesBaseProtocol(r)
+}
+
 class RefinedClass : BaseClass, RefinedProtocol {
   func takesT(_: T) {
     _ = T.self

test/decl/protocol/protocol_with_superclass_where_clause.swift

@@ -300,6 +300,12 @@ class RefinedClass : BaseClass, RefinedProtocol {
   }
 }
 
+func takesBaseProtocol(_: BaseProtocol) {}
+
+func passesRefinedProtocol(_ r: RefinedProtocol) {
+  takesBaseProtocol(r)
+}
+
 class LoopClass : LoopProto {}
 protocol LoopProto where Self : LoopClass {}