diff --git a/include/swift/AST/DiagnosticsSema.def b/include/swift/AST/DiagnosticsSema.def
index a17af549f77..bebb032b14b 100644
--- a/include/swift/AST/DiagnosticsSema.def
+++ b/include/swift/AST/DiagnosticsSema.def
@@ -1187,14 +1187,19 @@ ERROR(access_control_setter_more,none,
       "%select{variable|property|subscript}1 cannot have "
       "%select{%error|a fileprivate|an internal|a public|an open}2 setter",
       (AccessLevel, unsigned, AccessLevel))
+WARNING(access_control_setter_redundant,none,
+      "'%select{private|fileprivate|internal|public|open}0(set)' modifier is "
+      "redundant for %select{a private|a fileprivate|an internal|a public|an open}2 "
+      "%1",
+      (AccessLevel, DescriptiveDeclKind, AccessLevel))
 WARNING(access_control_ext_member_more,none,
     "declaring %select{%error|a fileprivate|an internal|a public|open}0 %1 in "
     "%select{a private|a fileprivate|an internal|a public|%error}2 extension",
     (AccessLevel, DescriptiveDeclKind, AccessLevel))
 WARNING(access_control_ext_member_redundant,none,
     "'%select{%error|fileprivate|internal|public|%error}0' modifier is redundant "
-    "for %1 declared in %select{%error|a fileprivate|an internal|a public|%error}2 "
-    "extension",
+    "for %1 declared in %select{a private (equivalent to fileprivate)|a fileprivate"
+    "|an internal|a public|%error}2 extension",
     (AccessLevel, DescriptiveDeclKind, AccessLevel))
 ERROR(access_control_ext_requirement_member_more,none,
     "cannot declare %select{%error|a fileprivate|an internal|a public|an open}0 %1 "
diff --git a/lib/Sema/MiscDiagnostics.cpp b/lib/Sema/MiscDiagnostics.cpp
index 96463386b08..f6cd85c0c37 100644
--- a/lib/Sema/MiscDiagnostics.cpp
+++ b/lib/Sema/MiscDiagnostics.cpp
@@ -3952,7 +3952,7 @@ void swift::performStmtDiagnostics(TypeChecker &TC, const Stmt *S) {
 
 void swift::fixItAccess(InFlightDiagnostic &diag, ValueDecl *VD,
                         AccessLevel desiredAccess, bool isForSetter,
-                        bool shouldNotReplace) {
+                        bool shouldUseDefaultAccess) {
   StringRef fixItString;
   switch (desiredAccess) {
   case AccessLevel::Private:      fixItString = "private ";      break;
@@ -3998,7 +3998,7 @@ void swift::fixItAccess(InFlightDiagnostic &diag, ValueDecl *VD,
     // this function is sometimes called to make access narrower, so assuming
     // that a broader scope is acceptable breaks some diagnostics.
     if (attr->getAccess() != desiredAccess) {
-      if (shouldNotReplace) {
+      if (shouldUseDefaultAccess) {
         // Remove the attribute if replacement is not preferred.
         diag.fixItRemove(attr->getRange());
       } else {
diff --git a/lib/Sema/MiscDiagnostics.h b/lib/Sema/MiscDiagnostics.h
index 5864a3c9eb4..e0d53b6580f 100644
--- a/lib/Sema/MiscDiagnostics.h
+++ b/lib/Sema/MiscDiagnostics.h
@@ -55,7 +55,7 @@ void fixItAccess(InFlightDiagnostic &diag,
                  ValueDecl *VD,
                  AccessLevel desiredAccess,
                  bool isForSetter = false,
-                 bool shouldNotReplace = false);
+                 bool shouldUseDefaultAccess = false);
 
 /// Emit fix-its to correct the argument labels in \p expr, which is the
 /// argument tuple or single argument of a call.
diff --git a/lib/Sema/TypeCheckAttr.cpp b/lib/Sema/TypeCheckAttr.cpp
index 2bfeb01f509..33e8d00230a 100644
--- a/lib/Sema/TypeCheckAttr.cpp
+++ b/lib/Sema/TypeCheckAttr.cpp
@@ -1459,13 +1459,6 @@ static bool hasThrowingFunctionParameter(CanType type) {
   return false;
 }
 
-static inline bool isRedundantAttrInExtension(AccessLevel access,
-                                              AccessControlAttr *extAttr) {
-  return access == extAttr->getAccess() &&
-         access != AccessLevel::Private &&
-         access != AccessLevel::Open;
-}
-
 void AttributeChecker::visitRethrowsAttr(RethrowsAttr *attr) {
   // 'rethrows' only applies to functions that take throwing functions
   // as parameters.
@@ -1519,22 +1512,17 @@ void AttributeChecker::visitAccessControlAttr(AccessControlAttr *attr) {
 
     if (auto extAttr =
         extension->getAttrs().getAttribute<AccessControlAttr>()) {
-      // Extensions are top level declarations, for which the literally lowest
-      // access level `private` is equivalent to `fileprivate`.
-      AccessLevel extAccess = std::max(extAttr->getAccess(),
-                                       AccessLevel::FilePrivate);
-      if (attr->getAccess() > extAccess) {
+      AccessLevel defaultAccess = extension->getDefaultAccessLevel();
+      if (attr->getAccess() > defaultAccess) {
         auto diag = TC.diagnose(attr->getLocation(),
                                 diag::access_control_ext_member_more,
                                 attr->getAccess(),
                                 D->getDescriptiveKind(),
                                 extAttr->getAccess());
-        bool shouldNotReplace = isRedundantAttrInExtension(extAccess, extAttr);
-        swift::fixItAccess(diag, cast<ValueDecl>(D), extAccess, false,
-                           shouldNotReplace);
+        swift::fixItAccess(diag, cast<ValueDecl>(D), defaultAccess, false,
+                           true);
         return;
-      }
-      if (isRedundantAttrInExtension(attr->getAccess(), extAttr)) {
+      } else if (attr->getAccess() == defaultAccess) {
         TC.diagnose(attr->getLocation(),
                     diag::access_control_ext_member_redundant,
                     attr->getAccess(),
@@ -1576,6 +1564,15 @@ AttributeChecker::visitSetterAccessAttr(SetterAccessAttr *attr) {
                 getterAccess, storageKind, attr->getAccess());
     attr->setInvalid();
     return;
+
+  } else if (attr->getAccess() == getterAccess) {
+    TC.diagnose(attr->getLocation(),
+                diag::access_control_setter_redundant,
+                attr->getAccess(),
+                D->getDescriptiveKind(),
+                getterAccess)
+      .fixItRemove(attr->getRange());
+    return;
   }
 }
 
diff --git a/test/Compatibility/accessibility.swift b/test/Compatibility/accessibility.swift
index e6b83078d77..a63f103c51b 100644
--- a/test/Compatibility/accessibility.swift
+++ b/test/Compatibility/accessibility.swift
@@ -89,8 +89,8 @@ fileprivate extension PublicStruct {
   private func extImplFilePrivate() {}
 }
 private extension PublicStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 public extension InternalStruct { // expected-error {{extension of internal struct cannot be declared public}} {{1-8=}}
@@ -109,8 +109,8 @@ fileprivate extension InternalStruct {
   private func extImplFilePrivate() {}
 }
 private extension InternalStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 public extension FilePrivateStruct { // expected-error {{extension of fileprivate struct cannot be declared public}} {{1-8=}}
@@ -129,8 +129,8 @@ fileprivate extension FilePrivateStruct {
   private func extImplFilePrivate() {}
 }
 private extension FilePrivateStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 public extension PrivateStruct { // expected-error {{extension of private struct cannot be declared public}} {{1-8=}}
@@ -149,8 +149,8 @@ fileprivate extension PrivateStruct { // expected-error {{extension of private s
   private func extImplFilePrivate() {}
 }
 private extension PrivateStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 
@@ -716,3 +716,90 @@ public typealias BadPublicComposition2 = PublicClass & InternalProto // expected
 public typealias BadPublicComposition3<T> = InternalGenericClass<T> & PublicProto // expected-error {{type alias cannot be declared public because its underlying type uses an internal type}}
 public typealias BadPublicComposition4 = InternalGenericClass<Int> & PublicProto // expected-error {{type alias cannot be declared public because its underlying type uses an internal type}}
 public typealias BadPublicComposition5 = PublicGenericClass<InternalStruct> & PublicProto // expected-error {{type alias cannot be declared public because its underlying type uses an internal type}}
+
+
+open class ClassWithProperties {
+  open open(set) var openProp = 0 // expected-warning {{'open(set)' modifier is redundant for an open property}} {{8-18=}}
+  public public(set) var publicProp = 0 // expected-warning {{'public(set)' modifier is redundant for a public property}} {{10-22=}}
+  internal internal(set) var internalProp = 0 // expected-warning {{'internal(set)' modifier is redundant for an internal property}} {{12-26=}}
+  fileprivate fileprivate(set) var fileprivateProp = 0 // expected-warning {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{15-32=}}
+  private private(set) var privateProp = 0 // expected-warning {{'private(set)' modifier is redundant for a private property}} {{11-24=}}
+  internal(set) var defaultProp = 0 // expected-warning {{'internal(set)' modifier is redundant for an internal property}} {{3-17=}}
+}
+
+extension ClassWithProperties {
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{12-26=}}
+  internal internal(set) var defaultExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{3-17=}}
+  internal(set) var defaultExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+public extension ClassWithProperties {
+  // expected-warning@+2 {{'public' modifier is redundant for property declared in a public extension}} {{3-10=}}
+  // expected-warning@+1 {{'public(set)' modifier is redundant for a public property}} {{10-22=}}
+  public public(set) var publicExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'public(set)' modifier is redundant for a public property}} {{3-15=}}
+  public(set) var publicExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+internal extension ClassWithProperties {
+  // expected-warning@+2 {{'internal' modifier is redundant for property declared in an internal extension}} {{3-12=}}
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{12-26=}}
+  internal internal(set) var internalExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{3-17=}}
+  internal(set) var internalExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+fileprivate extension ClassWithProperties {
+  // expected-warning@+2 {{'fileprivate' modifier is redundant for property declared in a fileprivate extension}} {{3-15=}}
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{15-32=}}
+  fileprivate fileprivate(set) var fileprivateExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{3-20=}}
+  fileprivate(set) var fileprivateExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+  private(set) var fileprivateExtProp3: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+private extension ClassWithProperties {
+  // expected-warning@+2 {{'fileprivate' modifier is redundant for property declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{15-32=}}
+  fileprivate fileprivate(set) var privateExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{3-20=}}
+  fileprivate(set) var privateExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+  private(set) var privateExtProp3: Int {
+    get { return 42 }
+    set {}
+  }
+}
diff --git a/test/Compatibility/tuple_arguments_4.swift b/test/Compatibility/tuple_arguments_4.swift
index b09b9be56a0..c5316d3af4c 100644
--- a/test/Compatibility/tuple_arguments_4.swift
+++ b/test/Compatibility/tuple_arguments_4.swift
@@ -1631,15 +1631,13 @@ do {
 
 // https://bugs.swift.org/browse/SR-6509
 public extension Optional {
-  // expected-warning@+1 {{'public' modifier is redundant for instance method declared in a public extension}}
-  public func apply<Result>(_ transform: ((Wrapped) -> Result)?) -> Result? {
+  func apply<Result>(_ transform: ((Wrapped) -> Result)?) -> Result? {
     return self.flatMap { value in
       transform.map { $0(value) }
     }
   }
 
-  // expected-warning@+1 {{'public' modifier is redundant for instance method declared in a public extension}}
-  public func apply<Value, Result>(_ value: Value?) -> Result?
+  func apply<Value, Result>(_ value: Value?) -> Result?
     where Wrapped == (Value) -> Result {
     return value.apply(self)
   }
diff --git a/test/Constraints/tuple_arguments.swift b/test/Constraints/tuple_arguments.swift
index 1d9aaaae87f..8f58255978a 100644
--- a/test/Constraints/tuple_arguments.swift
+++ b/test/Constraints/tuple_arguments.swift
@@ -1632,15 +1632,13 @@ do {
 
 // https://bugs.swift.org/browse/SR-6509
 public extension Optional {
-  // expected-warning@+1 {{'public' modifier is redundant for instance method declared in a public extension}}
-  public func apply<Result>(_ transform: ((Wrapped) -> Result)?) -> Result? {
+  func apply<Result>(_ transform: ((Wrapped) -> Result)?) -> Result? {
     return self.flatMap { value in
       transform.map { $0(value) }
     }
   }
 
-  // expected-warning@+1 {{'public' modifier is redundant for instance method declared in a public extension}}
-  public func apply<Value, Result>(_ value: Value?) -> Result?
+  func apply<Value, Result>(_ value: Value?) -> Result?
     where Wrapped == (Value) -> Result {
     return value.apply(self)
   }
diff --git a/test/SILGen/accessibility_warnings.swift b/test/SILGen/accessibility_warnings.swift
index d154fed4657..db0d236847a 100644
--- a/test/SILGen/accessibility_warnings.swift
+++ b/test/SILGen/accessibility_warnings.swift
@@ -15,6 +15,7 @@ internal struct InternalStruct {
 
   public private(set) var publicVarPrivateSet = 0
 
+  // expected-warning@+1 {{'public(set)' modifier is redundant for a public property}} {{10-22=}}
   public public(set) var publicVarPublicSet = 0
 
   // CHECK-DAG: sil hidden @$S22accessibility_warnings14InternalStructV16publicVarGetOnlySivg
@@ -56,6 +57,13 @@ extension PrivateStruct {
   public var publicVarExtension: Int { get { return 0 } set {} }
 }
 
+public extension PublicStruct {
+  // CHECK-DAG: sil @$S22accessibility_warnings12PublicStructV09extMemberC0yyF
+  public func extMemberPublic() {} // expected-warning {{'public' modifier is redundant for instance method declared in a public extension}} {{3-10=}}
+  // CHECK-DAG: sil private @$S22accessibility_warnings12PublicStructV07extImplC033_5D2F2E026754A901C0FF90C404896D02LLyyF
+  private func extImplPublic() {}
+}
+
 internal extension PublicStruct {
   // CHECK-DAG: sil hidden @$S22accessibility_warnings12PublicStructV17extMemberInternalyyF
   public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
@@ -64,7 +72,7 @@ internal extension PublicStruct {
 }
 private extension PublicStruct {
   // CHECK-DAG: sil private @$S22accessibility_warnings12PublicStructV16extMemberPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
   // CHECK-DAG: sil private @$S22accessibility_warnings12PublicStructV14extImplPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
   private func extImplPrivate() {}
 }
@@ -77,7 +85,7 @@ internal extension InternalStruct {
 }
 private extension InternalStruct {
   // CHECK-DAG: sil private @$S22accessibility_warnings14InternalStructV16extMemberPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
   // CHECK-DAG: sil private @$S22accessibility_warnings14InternalStructV14extImplPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
   private func extImplPrivate() {}
 }
@@ -85,7 +93,7 @@ private extension InternalStruct {
 
 private extension PrivateStruct {
   // CHECK-DAG: sil private @$S22accessibility_warnings13PrivateStruct33_5D2F2E026754A901C0FF90C404896D02LLV09extMemberC0yyF
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
   // CHECK-DAG: sil private @$S22accessibility_warnings13PrivateStruct33_5D2F2E026754A901C0FF90C404896D02LLV07extImplC0yyF
   private func extImplPrivate() {}
 }
@@ -120,6 +128,7 @@ internal class InternalClass {
   // CHECK-DAG: sil hidden [transparent] @$S22accessibility_warnings13InternalClassC19publicVarPrivateSetSivg
   public private(set) var publicVarPrivateSet = 0
 
+  // expected-warning@+1 {{'public(set)' modifier is redundant for a public property}} {{10-22=}}
   public public(set) var publicVarPublicSet = 0
 
   // CHECK-DAG: sil hidden @$S22accessibility_warnings13InternalClassC16publicVarGetOnlySivg
diff --git a/test/Sema/accessibility.swift b/test/Sema/accessibility.swift
index 84dfa09e927..4f2ec703476 100644
--- a/test/Sema/accessibility.swift
+++ b/test/Sema/accessibility.swift
@@ -89,8 +89,8 @@ fileprivate extension PublicStruct {
   private func extImplFilePrivate() {}
 }
 private extension PublicStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 public extension InternalStruct { // expected-error {{extension of internal struct cannot be declared public}} {{1-8=}}
@@ -109,8 +109,8 @@ fileprivate extension InternalStruct {
   private func extImplFilePrivate() {}
 }
 private extension InternalStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 public extension FilePrivateStruct { // expected-error {{extension of fileprivate struct cannot be declared public}} {{1-8=}}
@@ -129,8 +129,8 @@ fileprivate extension FilePrivateStruct {
   private func extImplFilePrivate() {}
 }
 private extension FilePrivateStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 public extension PrivateStruct { // expected-error {{extension of private struct cannot be declared public}} {{1-8=}}
@@ -149,8 +149,8 @@ fileprivate extension PrivateStruct { // expected-error {{extension of private s
   private func extImplFilePrivate() {}
 }
 private extension PrivateStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-9=fileprivate}}
-  fileprivate func extFuncPrivate() {}
+  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  fileprivate func extFuncPrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
   private func extImplPrivate() {}
 }
 
@@ -724,3 +724,90 @@ public typealias BadPublicComposition2 = PublicClass & InternalProto // expected
 public typealias BadPublicComposition3<T> = InternalGenericClass<T> & PublicProto // expected-error {{type alias cannot be declared public because its underlying type uses an internal type}}
 public typealias BadPublicComposition4 = InternalGenericClass<Int> & PublicProto // expected-error {{type alias cannot be declared public because its underlying type uses an internal type}}
 public typealias BadPublicComposition5 = PublicGenericClass<InternalStruct> & PublicProto // expected-error {{type alias cannot be declared public because its underlying type uses an internal type}}
+
+
+open class ClassWithProperties {
+  open open(set) var openProp = 0 // expected-warning {{'open(set)' modifier is redundant for an open property}} {{8-18=}}
+  public public(set) var publicProp = 0 // expected-warning {{'public(set)' modifier is redundant for a public property}} {{10-22=}}
+  internal internal(set) var internalProp = 0 // expected-warning {{'internal(set)' modifier is redundant for an internal property}} {{12-26=}}
+  fileprivate fileprivate(set) var fileprivateProp = 0 // expected-warning {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{15-32=}}
+  private private(set) var privateProp = 0 // expected-warning {{'private(set)' modifier is redundant for a private property}} {{11-24=}}
+  internal(set) var defaultProp = 0 // expected-warning {{'internal(set)' modifier is redundant for an internal property}} {{3-17=}}
+}
+
+extension ClassWithProperties {
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{12-26=}}
+  internal internal(set) var defaultExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{3-17=}}
+  internal(set) var defaultExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+public extension ClassWithProperties {
+  // expected-warning@+2 {{'public' modifier is redundant for property declared in a public extension}} {{3-10=}}
+  // expected-warning@+1 {{'public(set)' modifier is redundant for a public property}} {{10-22=}}
+  public public(set) var publicExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'public(set)' modifier is redundant for a public property}} {{3-15=}}
+  public(set) var publicExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+internal extension ClassWithProperties {
+  // expected-warning@+2 {{'internal' modifier is redundant for property declared in an internal extension}} {{3-12=}}
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{12-26=}}
+  internal internal(set) var internalExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'internal(set)' modifier is redundant for an internal property}} {{3-17=}}
+  internal(set) var internalExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+fileprivate extension ClassWithProperties {
+  // expected-warning@+2 {{'fileprivate' modifier is redundant for property declared in a fileprivate extension}} {{3-15=}}
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{15-32=}}
+  fileprivate fileprivate(set) var fileprivateExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{3-20=}}
+  fileprivate(set) var fileprivateExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+  private(set) var fileprivateExtProp3: Int {
+    get { return 42 }
+    set {}
+  }
+}
+
+private extension ClassWithProperties {
+  // expected-warning@+2 {{'fileprivate' modifier is redundant for property declared in a private (equivalent to fileprivate) extension}} {{3-15=}}
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{15-32=}}
+  fileprivate fileprivate(set) var privateExtProp: Int {
+    get { return 42 }
+    set {}
+  }
+  // expected-warning@+1 {{'fileprivate(set)' modifier is redundant for a fileprivate property}} {{3-20=}}
+  fileprivate(set) var privateExtProp2: Int {
+    get { return 42 }
+    set {}
+  }
+  private(set) var privateExtProp3: Int {
+    get { return 42 }
+    set {}
+  }
+}