[Frontend] Remove enable-experimental-enum-codable-derivation flag

SE-295 has been accepted, so we don't need to hide the feature behind a flag anymore.

Author: drexin

include/swift/Basic/LangOptions.h

@@ -256,9 +256,6 @@ namespace swift {
     /// Enable inference of Sendable conformances for public types.
     bool EnableInferPublicSendable = false;
 
-    /// Enable experimental derivation of `Codable` for enums.
-    bool EnableExperimentalEnumCodableDerivation = false;
-
     /// Disable the implicit import of the _Concurrency module.
     bool DisableImplicitConcurrencyModuleImport = false;
 

include/swift/Option/FrontendOptions.td

@@ -233,10 +233,6 @@ def enable_experimental_flow_sensitive_concurrent_captures :
   Flag<["-"], "enable-experimental-flow-sensitive-concurrent-captures">,
   HelpText<"Enable flow-sensitive concurrent captures">;
 
-def enable_experimental_enum_codable_derivation :
-  Flag<["-"], "enable-experimental-enum-codable-derivation">,
-  HelpText<"Enable experimental derivation of Codable for enums">;
-
 def enable_resilience : Flag<["-"], "enable-resilience">,
      HelpText<"Deprecated, use -enable-library-evolution instead">;
 }

lib/Frontend/CompilerInvocation.cpp

@@ -392,9 +392,6 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
   Opts.EnableExperimentalFlowSensitiveConcurrentCaptures |=
     Args.hasArg(OPT_enable_experimental_flow_sensitive_concurrent_captures);
 
-  Opts.EnableExperimentalEnumCodableDerivation |=
-      Args.hasArg(OPT_enable_experimental_enum_codable_derivation);
-
   Opts.DisableImplicitConcurrencyModuleImport |=
     Args.hasArg(OPT_disable_implicit_concurrency_module_import);
 

lib/Sema/DerivedConformanceCodable.cpp

@@ -2014,9 +2014,7 @@ static bool canDeriveCodable(NominalTypeDecl *NTD,
   // Structs, classes and enums can explicitly derive Encodable and Decodable
   // conformance (explicitly meaning we can synthesize an implementation if
   // a type conforms manually).
-  if (!isa<StructDecl>(NTD) && !isa<ClassDecl>(NTD) &&
-      !(NTD->getASTContext().LangOpts.EnableExperimentalEnumCodableDerivation
-        && isa<EnumDecl>(NTD))) {
+  if (!isa<StructDecl>(NTD) && !isa<ClassDecl>(NTD) && !isa<EnumDecl>(NTD)) {
     return false;
   }
 
@@ -2039,8 +2037,7 @@ bool DerivedConformance::canDeriveEncodable(NominalTypeDecl *NTD) {
 ValueDecl *DerivedConformance::deriveEncodable(ValueDecl *requirement) {
   // We can only synthesize Encodable for structs and classes.
   if (!isa<StructDecl>(Nominal) && !isa<ClassDecl>(Nominal) &&
-      !(Context.LangOpts.EnableExperimentalEnumCodableDerivation
-        && isa<EnumDecl>(Nominal)))
+      !isa<EnumDecl>(Nominal))
     return nullptr;
 
   if (requirement->getBaseName() != Context.Id_encode) {
@@ -2070,8 +2067,7 @@ ValueDecl *DerivedConformance::deriveEncodable(ValueDecl *requirement) {
 ValueDecl *DerivedConformance::deriveDecodable(ValueDecl *requirement) {
   // We can only synthesize Encodable for structs and classes.
   if (!isa<StructDecl>(Nominal) && !isa<ClassDecl>(Nominal) &&
-      !(Context.LangOpts.EnableExperimentalEnumCodableDerivation
-        && isa<EnumDecl>(Nominal)))
+      !isa<EnumDecl>(Nominal))
     return nullptr;
 
   if (requirement->getBaseName() != DeclBaseName::createConstructor()) {

test/decl/protocol/special/coding/enum_codable_case_identifier_overloads.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -verify-ignore-unknown -enable-experimental-enum-codable-derivation
+// RUN: %target-typecheck-verify-swift -verify-ignore-unknown
 
 // Simple enums with all Codable parameters whose CodingKeys come from a
 // typealias should get derived conformance to Codable.

test/decl/protocol/special/coding/enum_codable_codingkeys_typealias.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -verify-ignore-unknown -enable-experimental-enum-codable-derivation
+// RUN: %target-typecheck-verify-swift -verify-ignore-unknown
 
 // Simple enums with all Codable parameters whose CodingKeys come from a
 // typealias should get derived conformance to Codable.

test/decl/protocol/special/coding/enum_codable_conflicting_parameter_identifier.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -verify-ignore-unknown -enable-experimental-enum-codable-derivation
+// RUN: %target-typecheck-verify-swift -verify-ignore-unknown
 
 enum Duplicate : Codable { // expected-error {{type 'Duplicate' does not conform to protocol 'Decodable'}}
   // expected-error@-1 {{type 'Duplicate' does not conform to protocol 'Encodable'}}

test/decl/protocol/special/coding/enum_codable_excluded_optional_properties.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -enable-experimental-enum-codable-derivation
+// RUN: %target-typecheck-verify-swift
 
 enum EnumWithNonExcludedOptionalParameters : Codable { // expected-error {{type 'EnumWithNonExcludedOptionalParameters' does not conform to protocol 'Decodable'}}
     // expected-error@-1 {{type 'EnumWithNonExcludedOptionalParameters' does not conform to protocol 'Encodable'}}

test/decl/protocol/special/coding/enum_codable_failure_diagnostics.swift

@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -typecheck -parse-as-library -swift-version 4 %s -verify -enable-experimental-enum-codable-derivation
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -typecheck -parse-as-library -swift-version 4 %s -verify
 
 // Codable enum with non-Codable parameter.
 enum E1 : Codable {

test/decl/protocol/special/coding/enum_codable_ignore_nonconforming_property.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -verify-ignore-unknown -enable-experimental-enum-codable-derivation
+// RUN: %target-typecheck-verify-swift -verify-ignore-unknown
 
 struct NonCodable {}