AST: Replace PrimaryAssociatedTypeAttr with AssociatedTypeDecl::isPrimary() flag

Author: slavapestov

include/swift/AST/Attr.def

@@ -661,10 +661,7 @@ CONTEXTUAL_SIMPLE_DECL_ATTR(distributed, DistributedActor,
   APIBreakingToAdd | APIBreakingToRemove,
   118)
 
-SIMPLE_DECL_ATTR(_primaryAssociatedType,
-  PrimaryAssociatedType, OnAssociatedType | UserInaccessible |
-  APIStableToAdd | ABIStableToAdd | APIBreakingToRemove | ABIStableToRemove,
-  119)
+// 119 is unused
 
 SIMPLE_DECL_ATTR(_assemblyVision, EmitAssemblyVisionRemarks,
   OnFunc | UserInaccessible | NotSerialized | OnNominalType |

include/swift/AST/Decl.h

@@ -505,6 +505,11 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
     IsOpaqueType : 1
   );
 
+  SWIFT_INLINE_BITFIELD_FULL(AssociatedTypeDecl, AbstractTypeParamDecl, 1,
+    /// Whether this is a primary associated type.
+    IsPrimary : 1
+  );
+
   SWIFT_INLINE_BITFIELD_EMPTY(GenericTypeDecl, TypeDecl);
 
   SWIFT_INLINE_BITFIELD(TypeAliasDecl, GenericTypeDecl, 1+1,
@@ -3208,6 +3213,14 @@ class AssociatedTypeDecl : public AbstractTypeParamDecl {
                      LazyMemberLoader *definitionResolver,
                      uint64_t resolverData);
 
+  bool isPrimary() const {
+    return Bits.AssociatedTypeDecl.IsPrimary;
+  }
+
+  void setPrimary() {
+    Bits.AssociatedTypeDecl.IsPrimary = true;
+  }
+
   /// Get the protocol in which this associated type is declared.
   ProtocolDecl *getProtocol() const {
     return cast<ProtocolDecl>(getDeclContext());

lib/AST/Decl.cpp

@@ -4539,6 +4539,7 @@ AssociatedTypeDecl::AssociatedTypeDecl(DeclContext *dc, SourceLoc keywordLoc,
     : AbstractTypeParamDecl(DeclKind::AssociatedType, dc, name, nameLoc),
       KeywordLoc(keywordLoc), DefaultDefinition(defaultDefinition),
       TrailingWhere(trailingWhere) {
+  Bits.AssociatedTypeDecl.IsPrimary = 0;
 }
 
 AssociatedTypeDecl::AssociatedTypeDecl(DeclContext *dc, SourceLoc keywordLoc,

lib/Parse/ParseDecl.cpp

@@ -8040,8 +8040,7 @@ ParserStatus Parser::parsePrimaryAssociatedTypes(
     AssocType->getAttrs() = Attrs;
     if (!Inherited.empty())
       AssocType->setInherited(Context.AllocateCopy(Inherited));
-    AssocType->getAttrs().add(new (Context) PrimaryAssociatedTypeAttr(
-        /*Implicit=*/true));
+    AssocType->setPrimary();
 
     AssocTypes.push_back(AssocType);
 

lib/Sema/TypeCheckAttr.cpp

@@ -316,8 +316,6 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
 
   void visitUnsafeInheritExecutorAttr(UnsafeInheritExecutorAttr *attr);
 
-  void visitPrimaryAssociatedTypeAttr(PrimaryAssociatedTypeAttr *attr);
-
   void checkBackDeployAttrs(ArrayRef<BackDeployAttr *> Attrs);
 };
 
@@ -5894,10 +5892,6 @@ void AttributeChecker::visitUnsafeInheritExecutorAttr(
   }
 }
 
-void AttributeChecker::visitPrimaryAssociatedTypeAttr(
-    PrimaryAssociatedTypeAttr *attr) {
-}
-
 namespace {
 
 class ClosureAttributeChecker

lib/Sema/TypeCheckDecl.cpp

@@ -704,7 +704,7 @@ PrimaryAssociatedTypesRequest::evaluate(Evaluator &evaluator,
   SmallVector<AssociatedTypeDecl *, 2> assocTypes;
 
   for (auto *assocType : decl->getAssociatedTypeMembers()) {
-    if (assocType->getAttrs().hasAttribute<PrimaryAssociatedTypeAttr>())
+    if (assocType->isPrimary())
       assocTypes.push_back(assocType);
   }
 

lib/Sema/TypeCheckDeclOverride.cpp

@@ -1572,8 +1572,6 @@ namespace  {
     UNINTERESTING_ATTR(TypeSequence)
     UNINTERESTING_ATTR(CompileTimeConst)
 
-    UNINTERESTING_ATTR(PrimaryAssociatedType)
-
     UNINTERESTING_ATTR(BackDeploy)
 
     UNINTERESTING_ATTR(UnsafeInheritExecutor)

lib/Serialization/Deserialization.cpp

@@ -2777,11 +2777,13 @@ class DeclDeserializer {
     TypeID defaultDefinitionID;
     bool isImplicit;
     ArrayRef<uint64_t> rawOverriddenIDs;
+    bool isPrimary;
 
     decls_block::AssociatedTypeDeclLayout::readRecord(scratch, nameID,
                                                       contextID,
                                                       defaultDefinitionID,
                                                       isImplicit,
+                                                      isPrimary,
                                                       rawOverriddenIDs);
 
     auto DC = MF.getDeclContext(contextID);
@@ -2816,6 +2818,9 @@ class DeclDeserializer {
     }
     assocType->setOverriddenDecls(overriddenAssocTypes);
 
+    if (isPrimary)
+      assocType->setPrimary();
+
     return assocType;
   }
 

lib/Serialization/ModuleFormat.h

@@ -56,7 +56,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 674; // decl block renumbering
+const uint16_t SWIFTMODULE_VERSION_MINOR = 675; // primary associated types
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///
@@ -1233,6 +1233,7 @@ namespace decls_block {
     DeclContextIDField,  // context decl
     TypeIDField,         // default definition
     BCFixed<1>,          // implicit flag
+    BCFixed<1>,          // is primary
     BCArray<DeclIDField> // overridden associated types
   >;
 

lib/Serialization/Serialization.cpp

@@ -3465,6 +3465,7 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
       contextID.getOpaqueValue(),
       S.addTypeRef(assocType->getDefaultDefinitionType()),
       assocType->isImplicit(),
+      assocType->isPrimary(),
       overriddenAssocTypeIDs);
   }