Serialization: Rework serialization of nested archetypes.

Explicitly serialize the parent archetype so that it can be any kind of root archetype.

Author: jckarter

include/swift/Serialization/DeclTypeRecordNodes.def

@@ -88,7 +88,9 @@ TRAILING_INFO(TUPLE_TYPE_ELT)
 TYPE(FUNCTION)
 TRAILING_INFO(FUNCTION_PARAM)
 TYPE(METATYPE)
-TYPE(ARCHETYPE)
+TYPE(PRIMARY_ARCHETYPE)
+TYPE(OPENED_ARCHETYPE)
+TYPE(NESTED_ARCHETYPE)
 TYPE(PROTOCOL_COMPOSITION)
 TYPE(BOUND_GENERIC)
 

include/swift/Serialization/ModuleFormat.h

@@ -52,7 +52,7 @@ 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 = 474; // Last change: @_alwaysEmitIntoClient
+const uint16_t SWIFTMODULE_VERSION_MINOR = 475; // Last change: Generalize nested archetype serialization
 
 using DeclIDField = BCFixed<31>;
 
@@ -766,17 +766,24 @@ namespace decls_block {
     MetatypeRepresentationField        // representation
   >;
 
-  using ArchetypeTypeLayout = BCRecordLayout<
-    ARCHETYPE_TYPE,
+  using PrimaryArchetypeTypeLayout = BCRecordLayout<
+    PRIMARY_ARCHETYPE_TYPE,
     GenericEnvironmentIDField, // generic environment
-    TypeIDField                // interface type
+    BCVBR<4>, // generic type parameter depth
+    BCVBR<4>  // index + 1, or zero if we have a generic type parameter decl
   >;
 
-  using OpenedExistentialTypeLayout = BCRecordLayout<
-    OPENED_EXISTENTIAL_TYPE,
+  using OpenedArchetypeTypeLayout = BCRecordLayout<
+    OPENED_ARCHETYPE_TYPE,
     TypeIDField         // the existential type
   >;
-
+  
+  using NestedArchetypeTypeLayout = BCRecordLayout<
+    NESTED_ARCHETYPE_TYPE,
+    TypeIDField, // root archetype
+    TypeIDField // interface type relative to root
+  >;
+  
   using DynamicSelfTypeLayout = BCRecordLayout<
     DYNAMIC_SELF_TYPE,
     TypeIDField          // self type
@@ -1058,7 +1065,7 @@ namespace decls_block {
     // - the foreign error convention, if any
     // - inlinable body text, if any
   >;
-
+  
   // TODO: remove the unnecessary FuncDecl components here
   using AccessorLayout = BCRecordLayout<
     ACCESSOR_DECL,

lib/Serialization/Deserialization.cpp

@@ -3027,7 +3027,7 @@ class swift::DeclDeserializer {
       MF.error();
       return nullptr;
     }
-
+    
     // Set the interface type.
     fn->computeType();
 
@@ -4686,20 +4686,20 @@ Expected<Type> ModuleFile::getTypeChecked(TypeID TID) {
     break;
   }
 
-  case decls_block::ARCHETYPE_TYPE: {
+  case decls_block::PRIMARY_ARCHETYPE_TYPE: {
     GenericEnvironmentID envID;
-    TypeID interfaceTypeID;
+    unsigned depth, index;
 
-    decls_block::ArchetypeTypeLayout::readRecord(scratch, envID,
-                                                 interfaceTypeID);
+    decls_block::PrimaryArchetypeTypeLayout::readRecord(scratch, envID,
+                                                        depth, index);
 
     auto env = getGenericEnvironment(envID);
     if (!env) {
       error();
       break;
     }
 
-    Type interfaceType = getType(interfaceTypeID);
+    Type interfaceType = GenericTypeParamType::get(depth, index, ctx);
     Type contextType = env->mapTypeIntoContext(interfaceType);
     typeOrOffset = contextType;
 
@@ -4711,15 +4711,37 @@ Expected<Type> ModuleFile::getTypeChecked(TypeID TID) {
     break;
   }
 
-  case decls_block::OPENED_EXISTENTIAL_TYPE: {
+  case decls_block::OPENED_ARCHETYPE_TYPE: {
     TypeID existentialID;
 
-    decls_block::OpenedExistentialTypeLayout::readRecord(scratch,
-                                                         existentialID);
+    decls_block::OpenedArchetypeTypeLayout::readRecord(scratch,
+                                                       existentialID);
 
     typeOrOffset = OpenedArchetypeType::get(getType(existentialID));
     break;
   }
+      
+  case decls_block::NESTED_ARCHETYPE_TYPE: {
+    TypeID rootID, interfaceTyID;
+    decls_block::NestedArchetypeTypeLayout::readRecord(scratch,
+                                                       rootID, interfaceTyID);
+    
+    auto rootTy = getType(rootID)->castTo<ArchetypeType>();
+    auto interfaceTy = getType(interfaceTyID)->castTo<DependentMemberType>();
+    auto rootInterfaceTy = interfaceTy->getRootGenericParam();
+    
+    auto sig = rootTy->getGenericEnvironment()->getGenericSignature();
+    
+    auto subs = SubstitutionMap::get(sig,
+      [&](SubstitutableType *t) -> Type {
+        if (t->isEqual(rootInterfaceTy))
+          return rootTy;
+        return t;
+      }, LookUpConformanceInModule(getAssociatedModule()));
+    
+    typeOrOffset = Type(interfaceTy).subst(subs);
+    break;
+  }
 
   case decls_block::GENERIC_TYPE_PARAM_TYPE: {
     DeclID declIDOrDepth;

lib/Serialization/Serialization.cpp

@@ -3291,7 +3291,7 @@ void Serializer::writeDecl(const Decl *D) {
     Type ty = fn->getInterfaceType();
     for (auto dependency : collectDependenciesFromType(ty->getCanonicalType()))
       nameComponentsAndDependencies.push_back(addTypeRef(dependency));
-
+    
     FuncLayout::emitRecord(Out, ScratchRecord, abbrCode,
                            contextID,
                            fn->isImplicit(),
@@ -3328,7 +3328,7 @@ void Serializer::writeDecl(const Decl *D) {
 
     break;
   }
-
+      
   case DeclKind::Accessor: {
     auto fn = cast<AccessorDecl>(D);
     verifyAttrSerializable(fn);
@@ -3818,32 +3818,41 @@ void Serializer::writeType(Type ty) {
                                       addTypeRef(dynamicSelfTy->getSelfType()));
     break;
   }
-
-  case TypeKind::PrimaryArchetype:
-  case TypeKind::NestedArchetype: {
-    auto archetypeTy = cast<ArchetypeType>(ty.getPointer());
-    assert(isa<PrimaryArchetypeType>(archetypeTy->getRoot())
-           && "need to implement for nested archetypes of opened/opaque types");
-
+      
+  case TypeKind::PrimaryArchetype: {
+    auto archetypeTy = cast<PrimaryArchetypeType>(ty.getPointer());
     auto env = archetypeTy->getGenericEnvironment();
 
     GenericEnvironmentID envID = addGenericEnvironmentRef(env);
-    Type interfaceType = archetypeTy->getInterfaceType();
-
-    unsigned abbrCode = DeclTypeAbbrCodes[ArchetypeTypeLayout::Code];
-    ArchetypeTypeLayout::emitRecord(Out, ScratchRecord, abbrCode,
-                                    envID, addTypeRef(interfaceType));
+    auto interfaceType = archetypeTy->getInterfaceType()
+      ->castTo<GenericTypeParamType>();
+
+    unsigned abbrCode = DeclTypeAbbrCodes[PrimaryArchetypeTypeLayout::Code];
+    PrimaryArchetypeTypeLayout::emitRecord(Out, ScratchRecord, abbrCode,
+                                           envID,
+                                           interfaceType->getDepth(),
+                                           interfaceType->getIndex());
     break;
   }
 
   case TypeKind::OpenedArchetype: {
     auto archetypeTy = cast<OpenedArchetypeType>(ty.getPointer());
-    unsigned abbrCode = DeclTypeAbbrCodes[OpenedExistentialTypeLayout::Code];
-    OpenedExistentialTypeLayout::emitRecord(Out, ScratchRecord, abbrCode,
+    unsigned abbrCode = DeclTypeAbbrCodes[OpenedArchetypeTypeLayout::Code];
+    OpenedArchetypeTypeLayout::emitRecord(Out, ScratchRecord, abbrCode,
                            addTypeRef(archetypeTy->getOpenedExistentialType()));
     break;
   }
 
+  case TypeKind::NestedArchetype: {
+    auto archetypeTy = cast<NestedArchetypeType>(ty.getPointer());
+    auto rootTypeID = addTypeRef(archetypeTy->getRoot());
+    auto interfaceTypeID = addTypeRef(archetypeTy->getInterfaceType());
+    unsigned abbrCode = DeclTypeAbbrCodes[NestedArchetypeTypeLayout::Code];
+    NestedArchetypeTypeLayout::emitRecord(Out, ScratchRecord, abbrCode,
+                                          rootTypeID, interfaceTypeID);
+    break;
+  }
+
   case TypeKind::GenericTypeParam: {
     auto genericParam = cast<GenericTypeParamType>(ty.getPointer());
     unsigned abbrCode = DeclTypeAbbrCodes[GenericTypeParamTypeLayout::Code];
@@ -4098,7 +4107,9 @@ void Serializer::writeAllDeclsAndTypes() {
   registerDeclTypeAbbr<FunctionParamLayout>();
   registerDeclTypeAbbr<MetatypeTypeLayout>();
   registerDeclTypeAbbr<ExistentialMetatypeTypeLayout>();
-  registerDeclTypeAbbr<ArchetypeTypeLayout>();
+  registerDeclTypeAbbr<PrimaryArchetypeTypeLayout>();
+  registerDeclTypeAbbr<OpenedArchetypeTypeLayout>();
+  registerDeclTypeAbbr<NestedArchetypeTypeLayout>();
   registerDeclTypeAbbr<ProtocolCompositionTypeLayout>();
   registerDeclTypeAbbr<BoundGenericTypeLayout>();
   registerDeclTypeAbbr<GenericFunctionTypeLayout>();
@@ -4111,7 +4122,6 @@ void Serializer::writeAllDeclsAndTypes() {
   registerDeclTypeAbbr<UnboundGenericTypeLayout>();
   registerDeclTypeAbbr<OptionalTypeLayout>();
   registerDeclTypeAbbr<DynamicSelfTypeLayout>();
-  registerDeclTypeAbbr<OpenedExistentialTypeLayout>();
 
   registerDeclTypeAbbr<TypeAliasLayout>();
   registerDeclTypeAbbr<GenericTypeParamTypeLayout>();