Derive @_implements(Equatable, ==(_:_:)) _DerivedEnumEquals, not func==.

Author: graydon

include/swift/AST/KnownIdentifiers.def

@@ -90,6 +90,7 @@ IDENTIFIER_WITH_NAME(NativeClassLayout, "_NativeClass")
 // Operators
 IDENTIFIER_WITH_NAME(MatchOperator, "~=")
 IDENTIFIER_WITH_NAME(EqualsOperator, "==")
+IDENTIFIER_WITH_NAME(derived_enum_equals, "__derived_enum_equals")
 
 // Precedence groups
 IDENTIFIER(AssignmentPrecedence)

lib/Sema/DerivedConformanceEquatableHashable.cpp

@@ -196,7 +196,9 @@ deriveEquatable_enum_eq(TypeChecker &tc, Decl *parentDecl, EnumDecl *enumDecl) {
   //   case A, B, C
   //
   //   @derived
-  //   func ==(a: SomeEnum<T...>, b: SomeEnum<T...>) -> Bool {
+  //   @_implements(Equatable, ==(_:_:))
+  //   func __derived_enum_equals(a: SomeEnum<T...>,
+  //                              b: SomeEnum<T...>) -> Bool {
   //     var index_a: Int
   //     switch a {
   //     case .A: index_a = 0
@@ -239,7 +241,7 @@ deriveEquatable_enum_eq(TypeChecker &tc, Decl *parentDecl, EnumDecl *enumDecl) {
 
   auto boolTy = C.getBoolDecl()->getDeclaredType();
 
-  DeclName name(C, C.Id_EqualsOperator, params[1]);
+  DeclName name(C, C.Id_derived_enum_equals, params[1]);
   auto eqDecl =
     FuncDecl::create(C, /*StaticLoc=*/SourceLoc(),
                      StaticSpellingKind::KeywordStatic,
@@ -251,19 +253,27 @@ deriveEquatable_enum_eq(TypeChecker &tc, Decl *parentDecl, EnumDecl *enumDecl) {
                      TypeLoc::withoutLoc(boolTy),
                      parentDC);
   eqDecl->setImplicit();
+  eqDecl->setUserAccessible(false);
   eqDecl->getAttrs().add(new (C) InfixAttr(/*implicit*/false));
-  auto op = C.getStdlibModule()->lookupInfixOperator(C.Id_EqualsOperator);
-  if (!op) {
-    tc.diagnose(parentDecl->getLoc(),
-                diag::broken_equatable_eq_operator);
-    return nullptr;
-  }
+
+  // Add the @_implements(Equatable, ==(_:_:)) attribute
+  auto equatableProto = C.getProtocol(KnownProtocolKind::Equatable);
+  auto equatableTy = equatableProto->getDeclaredType();
+  auto equatableTypeLoc = TypeLoc::withoutLoc(equatableTy);
+  SmallVector<Identifier, 2> argumentLabels = { Identifier(), Identifier() };
+  auto equalsDeclName = DeclName(C, DeclBaseName(C.Id_EqualsOperator),
+                                 argumentLabels);
+  eqDecl->getAttrs().add(new (C) ImplementsAttr(SourceLoc(),
+                                                SourceRange(),
+                                                equatableTypeLoc,
+                                                equalsDeclName,
+                                                DeclNameLoc()));
+
   if (!C.getEqualIntDecl()) {
     tc.diagnose(parentDecl->getLoc(), diag::no_equal_overload_for_int);
     return nullptr;
   }
 
-  eqDecl->setOperatorDecl(op);
   eqDecl->setBodySynthesizer(&deriveBodyEquatable_enum_eq);
 
   // Compute the type.

test/IDE/print_ast_tc_decls.swift

@@ -585,7 +585,7 @@ struct d0200_EscapedIdentifiers {
   }
 // PASS_COMMON-NEXT: {{^}}  enum `enum` {{{$}}
 // PASS_COMMON-NEXT: {{^}}    case `case`{{$}}
-// PASS_COMMON-NEXT: {{^}}    static func ==(a: d0200_EscapedIdentifiers.`enum`, b: d0200_EscapedIdentifiers.`enum`) -> Bool
+// PASS_COMMON-NEXT: {{^}}    {{.*}}static func __derived_enum_equals(_ a: d0200_EscapedIdentifiers.`enum`, _ b: d0200_EscapedIdentifiers.`enum`) -> Bool
 // PASS_COMMON-NEXT: {{^}}    var hashValue: Int { get }{{$}}
 // PASS_COMMON-NEXT: {{^}}  }{{$}}
 
@@ -1010,7 +1010,7 @@ enum d2000_EnumDecl1 {
 // PASS_COMMON: {{^}}enum d2000_EnumDecl1 {{{$}}
 // PASS_COMMON-NEXT: {{^}}  case ED1_First{{$}}
 // PASS_COMMON-NEXT: {{^}}  case ED1_Second{{$}}
-// PASS_COMMON-NEXT: {{^}}  static func ==(a: d2000_EnumDecl1, b: d2000_EnumDecl1) -> Bool
+// PASS_COMMON-NEXT: {{^}}  {{.*}}static func __derived_enum_equals(_ a: d2000_EnumDecl1, _ b: d2000_EnumDecl1) -> Bool
 // PASS_COMMON-NEXT: {{^}}  var hashValue: Int { get }{{$}}
 // PASS_COMMON-NEXT: {{^}}}{{$}}
 

test/IRGen/enum_derived.swift

@@ -18,8 +18,8 @@ enum E {
 
 // Check if the == comparison can be compiled to a simple icmp instruction.
 
-// CHECK-NORMAL-LABEL:define hidden swiftcc i1 @_T012enum_derived1EO2eeoiSbAC_ACtFZ(i8, i8)
-// CHECK-TESTABLE-LABEL:define{{( protected)?}} swiftcc i1 @_T012enum_derived1EO2eeoiSbAC_ACtFZ(i8, i8)
+// CHECK-NORMAL-LABEL:define hidden swiftcc i1 @_T012enum_derived1EO02__b1_A7_equalsSbAC_ACtFZ(i8, i8)
+// CHECK-TESTABLE-LABEL:define{{( protected)?}} swiftcc i1 @_T012enum_derived1EO02__b1_A7_equalsSbAC_ACtFZ(i8, i8)
 // CHECK: %2 = icmp eq i8 %0, %1
 // CHECK: ret i1 %2