synthesized comparable for enums

include/swift/AST/ASTContext.h

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -538,6 +538,9 @@ class ASTContext final {
   ConcreteDeclRef getBuiltinInitDecl(NominalTypeDecl *decl,
                                      KnownProtocolKind builtinProtocol,
                 llvm::function_ref<DeclName (ASTContext &ctx)> initName) const;
+
+  /// Retrieve the declaration of Swift.<(Int, Int) -> Bool.
+  FuncDecl *getLessThanIntDecl() const;
 
   /// Retrieve the declaration of Swift.==(Int, Int) -> Bool.
   FuncDecl *getEqualIntDecl() const;

include/swift/AST/DiagnosticsSema.def

@@ -2693,6 +2693,8 @@ ERROR(broken_case_iterable_requirement,none,
       "CaseIterable protocol is broken: unexpected requirement", ())
 ERROR(broken_raw_representable_requirement,none,
       "RawRepresentable protocol is broken: unexpected requirement", ())
+ERROR(broken_comparable_requirement,none,
+      "Comparable protocol is broken: unexpected requirement", ())
 ERROR(broken_equatable_requirement,none,
       "Equatable protocol is broken: unexpected requirement", ())
 ERROR(broken_hashable_requirement,none,
@@ -2705,6 +2707,8 @@ ERROR(broken_int_hashable_conformance,none,
       "Int type is broken: does not conform to Hashable", ())
 ERROR(broken_int_integer_literal_convertible_conformance,none,
       "Int type is broken: does not conform to ExpressibleByIntegerLiteral", ())
+ERROR(no_less_than_overload_for_int,none,
+      "no overload of '<' for Int", ())
 ERROR(no_equal_overload_for_int,none,
       "no overload of '==' for Int", ())
 ERROR(broken_coding_key_requirement,none,

include/swift/AST/KnownIdentifiers.def

@@ -142,8 +142,10 @@ IDENTIFIER_WITH_NAME(NativeClassLayout, "_NativeClass")
 
 // Operators
 IDENTIFIER_WITH_NAME(MatchOperator, "~=")
+IDENTIFIER_WITH_NAME(LessThanOperator, "<")
 IDENTIFIER_WITH_NAME(EqualsOperator, "==")
 IDENTIFIER_WITH_NAME(NegationOperator, "!")
+IDENTIFIER_WITH_NAME(derived_enum_less_than, "__derived_enum_less_than")
 IDENTIFIER_WITH_NAME(derived_enum_equals, "__derived_enum_equals")
 IDENTIFIER_WITH_NAME(derived_struct_equals, "__derived_struct_equals")
 

lib/AST/ASTContext.cpp

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -224,6 +224,9 @@ struct ASTContext::Implementation {
 #define FUNC_DECL(Name, Id) FuncDecl *Get##Name = nullptr;
 #include "swift/AST/KnownDecls.def"
 
+  /// func <Int, Int) -> Bool
+  FuncDecl *LessThanIntDecl = nullptr;
+
   /// func ==(Int, Int) -> Bool
   FuncDecl *EqualIntDecl = nullptr;
 
@@ -1083,30 +1086,37 @@ ASTContext::getBuiltinInitDecl(NominalTypeDecl *decl,
   return witness;
 }
 
-FuncDecl *ASTContext::getEqualIntDecl() const {
-  if (getImpl().EqualIntDecl)
-    return getImpl().EqualIntDecl;
+static 
+FuncDecl *getBinaryComparisonOperatorIntDecl(const ASTContext &C, StringRef op, FuncDecl *&cached) {
+  if (cached)
+    return cached;
 
-  if (!getIntDecl() || !getBoolDecl())
+  if (!C.getIntDecl() || !C.getBoolDecl())
     return nullptr;
 
-  auto intType = getIntDecl()->getDeclaredType();
+  auto intType = C.getIntDecl()->getDeclaredType();
   auto isIntParam = [&](AnyFunctionType::Param param) {
     return (!param.isVariadic() && !param.isInOut() &&
             param.getPlainType()->isEqual(intType));
   };
-  auto boolType = getBoolDecl()->getDeclaredType();
-  auto decl = lookupOperatorFunc(*this, "==",
-                                 intType, [=](FunctionType *type) {
+  auto boolType = C.getBoolDecl()->getDeclaredType();
+  auto decl = lookupOperatorFunc(C, op, intType, 
+      [=](FunctionType *type) {
     // Check for the signature: (Int, Int) -> Bool
     if (type->getParams().size() != 2) return false;
     if (!isIntParam(type->getParams()[0]) ||
         !isIntParam(type->getParams()[1])) return false;
     return type->getResult()->isEqual(boolType);
   });
-  getImpl().EqualIntDecl = decl;
+  cached = decl;
   return decl;
 }
+FuncDecl *ASTContext::getLessThanIntDecl() const {
+  return getBinaryComparisonOperatorIntDecl(*this, "<", getImpl().LessThanIntDecl);
+}
+FuncDecl *ASTContext::getEqualIntDecl() const {
+  return getBinaryComparisonOperatorIntDecl(*this, "==", getImpl().EqualIntDecl);
+}
 
 FuncDecl *ASTContext::getHashValueForDecl() const {
   if (getImpl().HashValueForDecl)

lib/Sema/CMakeLists.txt

@@ -22,6 +22,7 @@ add_swift_host_library(swiftSema STATIC
   DerivedConformanceCodable.cpp
   DerivedConformanceCodingKey.cpp
   DerivedConformanceEquatableHashable.cpp
+  DerivedConformanceComparable.cpp
   DerivedConformanceError.cpp
   DerivedConformanceRawRepresentable.cpp
   DerivedConformances.cpp
@@ -71,4 +72,3 @@ target_link_libraries(swiftSema PRIVATE
   swiftAST
   swiftParse
   swiftSerialization)
-