[5.0] Don't fix access of an 'open' decl in a 'public' extension

include/swift/AST/DiagnosticsSema.def

@@ -1207,9 +1207,10 @@ WARNING(access_control_setter_redundant,none,
       "%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))
+    "'%select{%error|fileprivate|internal|public|open}0' modifier conflicts "
+    "with extension's default access of "
+    "'%select{private|fileprivate|internal|public|%error}1'",
+    (AccessLevel, AccessLevel))
 WARNING(access_control_ext_member_redundant,none,
     "'%select{%error|fileprivate|internal|public|%error}0' modifier is redundant "
     "for %1 declared in %select{a private (equivalent to fileprivate)|a fileprivate"

lib/Sema/TypeCheckAttr.cpp

@@ -1633,19 +1633,18 @@ void AttributeChecker::visitAccessControlAttr(AccessControlAttr *attr) {
         auto diag = TC.diagnose(attr->getLocation(),
                                 diag::access_control_ext_member_more,
                                 attr->getAccess(),
-                                D->getDescriptiveKind(),
                                 extAttr->getAccess());
-        swift::fixItAccess(diag, cast<ValueDecl>(D), defaultAccess, false,
-                           true);
-        return;
+        // Don't try to fix this one; it's just a warning, and fixing it can
+        // lead to diagnostic fights between this and "declaration must be at
+        // least this accessible" checking for overrides and protocol
+        // requirements.
       } else if (attr->getAccess() == defaultAccess) {
         TC.diagnose(attr->getLocation(),
                     diag::access_control_ext_member_redundant,
                     attr->getAccess(),
                     D->getDescriptiveKind(),
                     extAttr->getAccess())
           .fixItRemove(attr->getRange());
-        return;
       }
     }
   }

test/ClangImporter/Inputs/custom-modules/ObjCParseExtras.h

@@ -241,3 +241,11 @@ struct NonTrivialToCopyWrapper {
 struct TrivialToCopy {
   __unsafe_unretained id field;
 };
+
+@interface OverrideInExtensionBase : NSObject
+- (void)method;
+- (void)accessWarning;
+@end
+
+@interface OverrideInExtensionSub : OverrideInExtensionBase
+@end

test/ClangImporter/objc_override.swift

@@ -115,6 +115,15 @@ class MyHashableNSObject: NSObject {
   }
 }
 
+// rdar://problem/47557376
+// Adding an override to someone else's class in an extension like this isn't
+// really sound, but it's allowed in Objective-C too.
+extension OverrideInExtensionSub {
+  open override func method() {}
+}
+public extension OverrideInExtensionSub {
+  open override func accessWarning() {} // expected-warning {{'open' modifier conflicts with extension's default access of 'public'}}
+}
 
 // FIXME: Remove -verify-ignore-unknown.
 // <unknown>:0: error: unexpected note produced: overridden declaration is here

test/Compatibility/accessibility.swift

@@ -80,17 +80,17 @@ public extension PublicStruct {
   private func extImplPublic() {}
 }
 internal extension PublicStruct {
-  public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
+  public func extMemberInternal() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'internal'}} {{none}}
   fileprivate func extFuncInternal() {}
   private func extImplInternal() {}
 }
 fileprivate extension PublicStruct {
-  public func extMemberFilePrivate() {} // expected-warning {{declaring a public instance method in a fileprivate extension}} {{3-10=}}
+  public func extMemberFilePrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'fileprivate'}} {{none}}
   fileprivate func extFuncFilePrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a fileprivate extension}} {{3-15=}}
   private func extImplFilePrivate() {}
 }
 private extension PublicStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   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() {}
 }
@@ -100,17 +100,17 @@ public extension InternalStruct { // expected-error {{extension of internal stru
   private func extImplPublic() {}
 }
 internal extension InternalStruct {
-  public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
+  public func extMemberInternal() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'internal'}} {{none}}
   fileprivate func extFuncInternal() {}
   private func extImplInternal() {}
 }
 fileprivate extension InternalStruct {
-  public func extMemberFilePrivate() {} // expected-warning {{declaring a public instance method in a fileprivate extension}} {{3-10=}}
+  public func extMemberFilePrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'fileprivate'}} {{none}}
   fileprivate func extFuncFilePrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a fileprivate extension}} {{3-15=}}
   private func extImplFilePrivate() {}
 }
 private extension InternalStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   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() {}
 }
@@ -120,17 +120,17 @@ public extension FilePrivateStruct { // expected-error {{extension of fileprivat
   private func extImplPublic() {}
 }
 internal extension FilePrivateStruct { // expected-error {{extension of fileprivate struct cannot be declared internal}} {{1-10=}}
-  public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
+  public func extMemberInternal() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'internal'}} {{none}}
   fileprivate func extFuncInternal() {}
   private func extImplInternal() {}
 }
 fileprivate extension FilePrivateStruct {
-  public func extMemberFilePrivate() {} // expected-warning {{declaring a public instance method in a fileprivate extension}} {{3-10=}}
+  public func extMemberFilePrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'fileprivate'}} {{none}}
   fileprivate func extFuncFilePrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a fileprivate extension}} {{3-15=}}
   private func extImplFilePrivate() {}
 }
 private extension FilePrivateStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   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() {}
 }
@@ -140,17 +140,17 @@ public extension PrivateStruct { // expected-error {{extension of private struct
   private func extImplPublic() {}
 }
 internal extension PrivateStruct { // expected-error {{extension of private struct cannot be declared internal}} {{1-10=}}
-  public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
+  public func extMemberInternal() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'internal'}} {{none}}
   fileprivate func extFuncInternal() {}
   private func extImplInternal() {}
 }
 fileprivate extension PrivateStruct { // expected-error {{extension of private struct cannot be declared fileprivate}} {{1-13=}}
-  public func extMemberFilePrivate() {} // expected-warning {{declaring a public instance method in a fileprivate extension}} {{3-10=}}
+  public func extMemberFilePrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'fileprivate'}} {{none}}
   fileprivate func extFuncFilePrivate() {} // expected-warning {{'fileprivate' modifier is redundant for instance method declared in a fileprivate extension}} {{3-15=}}
   private func extImplFilePrivate() {}
 }
 private extension PrivateStruct {
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   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() {}
 }
@@ -175,10 +175,10 @@ public class Base {
 
 
 public extension Base {
-  open func extMemberPublic() {} // expected-warning {{declaring open instance method in a public extension}}
+  open func extMemberPublic() {} // expected-warning {{'open' modifier conflicts with extension's default access of 'public'}} {{none}}
 }
 internal extension Base {
-  open func extMemberInternal() {} // expected-warning {{declaring open instance method in an internal extension}}
+  open func extMemberInternal() {} // expected-warning {{'open' modifier conflicts with extension's default access of 'internal'}} {{none}}
 }
 
 public class PublicSub: Base {

test/SILGen/accessibility_warnings.swift

@@ -65,35 +65,35 @@ public extension PublicStruct {
 }
 
 internal extension PublicStruct {
-  // CHECK-DAG: sil hidden @$s22accessibility_warnings12PublicStructV17extMemberInternalyyF
-  public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
+  // CHECK-DAG: sil @$s22accessibility_warnings12PublicStructV17extMemberInternalyyF
+  public func extMemberInternal() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'internal'}} {{none}}
   // CHECK-DAG: sil private @$s22accessibility_warnings12PublicStructV15extImplInternal33_5D2F2E026754A901C0FF90C404896D02LLyyF
   private func extImplInternal() {}
 }
 private extension PublicStruct {
-  // CHECK-DAG: sil private @$s22accessibility_warnings12PublicStructV16extMemberPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  // CHECK-DAG: sil @$s22accessibility_warnings12PublicStructV16extMemberPrivateyyF
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   // CHECK-DAG: sil private @$s22accessibility_warnings12PublicStructV14extImplPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
   private func extImplPrivate() {}
 }
 
 internal extension InternalStruct {
   // CHECK-DAG: sil hidden @$s22accessibility_warnings14InternalStructV09extMemberC0yyF
-  public func extMemberInternal() {} // expected-warning {{declaring a public instance method in an internal extension}} {{3-10=}}
+  public func extMemberInternal() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'internal'}} {{none}}
   // CHECK-DAG: sil private @$s22accessibility_warnings14InternalStructV07extImplC033_5D2F2E026754A901C0FF90C404896D02LLyyF
   private func extImplInternal() {}
 }
 private extension InternalStruct {
-  // CHECK-DAG: sil private @$s22accessibility_warnings14InternalStructV16extMemberPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  // CHECK-DAG: sil hidden @$s22accessibility_warnings14InternalStructV16extMemberPrivateyyF
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   // CHECK-DAG: sil private @$s22accessibility_warnings14InternalStructV14extImplPrivate33_5D2F2E026754A901C0FF90C404896D02LLyyF
   private func extImplPrivate() {}
 }
 
 
 private extension PrivateStruct {
   // CHECK-DAG: sil private @$s22accessibility_warnings13PrivateStruct33_5D2F2E026754A901C0FF90C404896D02LLV09extMemberC0yyF
-  public func extMemberPrivate() {} // expected-warning {{declaring a public instance method in a private extension}} {{3-10=}}
+  public func extMemberPrivate() {} // expected-warning {{'public' modifier conflicts with extension's default access of 'private'}} {{none}}
   // CHECK-DAG: sil private @$s22accessibility_warnings13PrivateStruct33_5D2F2E026754A901C0FF90C404896D02LLV07extImplC0yyF
   private func extImplPrivate() {}
 }