[Serialization] ProtocolLayout: Serialize superclass

Author: xedin

lib/Serialization/Deserialization.cpp

@@ -4423,13 +4423,15 @@ class DeclDeserializer {
     IdentifierID nameID;
     DeclContextID contextID;
     bool isImplicit, isClassBounded, isObjC, hasSelfOrAssocTypeRequirements;
+    TypeID superclassID;
     uint8_t rawAccessLevel;
     unsigned numInheritedTypes;
     ArrayRef<uint64_t> rawInheritedAndDependencyIDs;
 
     decls_block::ProtocolLayout::readRecord(scratch, nameID, contextID,
                                             isImplicit, isClassBounded, isObjC,
                                             hasSelfOrAssocTypeRequirements,
+                                            superclassID,
                                             rawAccessLevel, numInheritedTypes,
                                             rawInheritedAndDependencyIDs);
 
@@ -4455,6 +4457,8 @@ class DeclDeserializer {
         /*TrailingWhere=*/nullptr);
     declOrOffset = proto;
 
+    proto->setSuperclass(MF.getType(superclassID));
+
     ctx.evaluator.cacheOutput(ProtocolRequiresClassRequest{proto},
                               std::move(isClassBounded));
     ctx.evaluator.cacheOutput(HasSelfOrAssociatedTypeRequirementsRequest{proto},

lib/Serialization/ModuleFormat.h

@@ -58,7 +58,7 @@ 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 = 855; // ref_adhoc_requirement_witness attributes are back
+const uint16_t SWIFTMODULE_VERSION_MINOR = 857; // Add superclass to protocol layout
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///
@@ -1527,6 +1527,7 @@ namespace decls_block {
     BCFixed<1>,             // class-bounded?
     BCFixed<1>,             // objc?
     BCFixed<1>,             // existential-type-supported?
+    TypeIDField,            // superclass
     AccessLevelField,       // access level
     BCVBR<4>,               // number of inherited types
     BCArray<TypeIDField>    // inherited types, followed by dependency types

lib/Serialization/Serialization.cpp

@@ -4325,6 +4325,7 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
                                  ->requiresClass(),
                                proto->isObjC(),
                                proto->hasSelfOrAssociatedTypeRequirements(),
+                               S.addTypeRef(proto->getSuperclass()),
                                rawAccessLevel, numInherited,
                                inheritedAndDependencyTypes);