Sema: add a @_semantics attribute to synthesized enum comparison functions

So that optimizations can identify and deal with them.

Author: eeckstein

include/swift/AST/SemanticAttrs.def

@@ -73,6 +73,8 @@ SEMANTICS_ATTR(OPTIMIZE_SIL_SPECIALIZE_GENERIC_PARTIAL_NEVER,
           "optimize.sil.specialize.generic.partial.never")
 SEMANTICS_ATTR(OPTIMIZE_SIL_INLINE_CONSTANT_ARGUMENTS,
           "optimize.sil.inline.constant.arguments")
+SEMANTICS_ATTR(DERIVED_ENUM_EQUALS,
+          "derived_enum_equals")
 SEMANTICS_ATTR(OPTIMIZE_SIL_SPECIALIZE_GENERIC_SIZE_NEVER,
           "optimize.sil.specialize.generic.size.never")
 SEMANTICS_ATTR(OPTIMIZE_SIL_SPECIALIZE_OWNED2GUARANTEE_NEVER,

lib/Sema/DerivedConformance/DerivedConformanceEquatableHashable.cpp

@@ -394,10 +394,12 @@ deriveEquatable_eq(
   auto boolTy = C.getBoolType();
 
   Identifier generatedIdentifier;
+  bool isDerivedEnumEquals = false;
   if (parentDC->getParentModule()->isResilient()) {
     generatedIdentifier = C.Id_EqualsOperator;
   } else if (selfIfaceTy->getEnumOrBoundGenericEnum()) {
     generatedIdentifier = C.Id_derived_enum_equals;
+    isDerivedEnumEquals = true;
   } else {
     assert(selfIfaceTy->getStructOrBoundGenericStruct());
     generatedIdentifier = C.Id_derived_struct_equals;
@@ -411,6 +413,9 @@ deriveEquatable_eq(
       /*GenericParams=*/nullptr, params, boolTy, parentDC);
   eqDecl->setUserAccessible(false);
   eqDecl->setSynthesized();
+  if (isDerivedEnumEquals) {
+    eqDecl->getAttrs().add(new (C) SemanticsAttr("derived_enum_equals", SourceLoc(), SourceRange(), /*Implicit=*/true));
+  }
 
   // Add the @_implements(Equatable, ==(_:_:)) attribute
   if (generatedIdentifier != C.Id_EqualsOperator) {

test/SILGen/synthesized_conformance_class.swift

@@ -56,7 +56,7 @@ class Nonfinal<T> {
 
 // CHECK-LABEL: sil private [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}11stringValueAFyx_GSgSS_tcfC : $@convention(method) <T> (@owned String, @thin Final<T>.CodingKeys.Type) -> Optional<Final<T>.CodingKeys> {
 // CHECK-LABEL: sil private [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}8intValueAFyx_GSgSi_tcfC : $@convention(method) <T> (Int, @thin Final<T>.CodingKeys.Type) -> Optional<Final<T>.CodingKeys> {
-// CHECK-LABEL: sil private [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}21__derived_enum_equalsySbAFyx_G_AHtFZ : $@convention(method) <T> (Final<T>.CodingKeys, Final<T>.CodingKeys, @thin Final<T>.CodingKeys.Type) -> Bool {
+// CHECK-LABEL: sil private [_semantics "derived_enum_equals"] [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}21__derived_enum_equalsySbAFyx_G_AHtFZ : $@convention(method) <T> (Final<T>.CodingKeys, Final<T>.CodingKeys, @thin Final<T>.CodingKeys.Type) -> Bool {
 // CHECK-LABEL: sil private [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}4hash4intoys6HasherVz_tF : $@convention(method) <T> (@inout Hasher, Final<T>.CodingKeys) -> () {
 // CHECK-LABEL: sil private [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}9hashValueSivg : $@convention(method) <T> (Final<T>.CodingKeys) -> Int {
 // CHECK-LABEL: sil private [ossa] @$s29synthesized_conformance_class5FinalC10CodingKeys{{.*}}8intValueSiSgvg : $@convention(method) <T> (Final<T>.CodingKeys) -> Optional<Int> {

test/SILGen/synthesized_conformance_enum.swift

@@ -37,7 +37,7 @@ enum NoValues {
 extension Enum: Equatable where T: Equatable {}
 // CHECK-FRAGILE-LABEL: // static Enum<A>.__derived_enum_equals(_:_:)
 // CHECK-FRAGILE-NEXT: // Isolation: unspecified
-// CHECK-FRAGILE-NEXT: sil hidden [ossa] @$s28synthesized_conformance_enum4EnumOAASQRzlE010__derived_C7_equalsySbACyxG_AEtFZ : $@convention(method) <T where T : Equatable> (@in_guaranteed Enum<T>, @in_guaranteed Enum<T>, @thin Enum<T>.Type) -> Bool {
+// CHECK-FRAGILE-NEXT: sil hidden [_semantics "derived_enum_equals"] [ossa] @$s28synthesized_conformance_enum4EnumOAASQRzlE010__derived_C7_equalsySbACyxG_AEtFZ : $@convention(method) <T where T : Equatable> (@in_guaranteed Enum<T>, @in_guaranteed Enum<T>, @thin Enum<T>.Type) -> Bool {
 // CHECK-RESILIENT-LABEL: // static Enum<A>.== infix(_:_:)
 // CHECK-RESILIENT-NEXT: // Isolation: unspecified
 // CHECK-RESILIENT-NEXT: sil hidden [ossa] @$s28synthesized_conformance_enum4EnumOAASQRzlE2eeoiySbACyxG_AEtFZ : $@convention(method) <T where T : Equatable> (@in_guaranteed Enum<T>, @in_guaranteed Enum<T>, @thin Enum<T>.Type) -> Bool {