Serialization: Support PackType and PackExpansionType

Author: slavapestov

lib/Serialization/DeclTypeRecordNodes.def

@@ -113,6 +113,10 @@ TYPE(SIL_MOVE_ONLY)
 TYPE(SIL_BOX)
 TYPE(NAME_ALIAS)
 
+TYPE(PACK_EXPANSION)
+TYPE(PACK)
+TRAILING_INFO(PACK_TYPE_ELT)
+
 TYPE(ERROR)
 
 FIRST_DECL(TYPE_ALIAS, 40)

lib/Serialization/Deserialization.cpp

@@ -6431,6 +6431,51 @@ Expected<Type> DESERIALIZE_TYPE(UNBOUND_GENERIC_TYPE)(
   return UnboundGenericType::get(genericDecl, parentTy, MF.getContext());
 }
 
+Expected<Type> DESERIALIZE_TYPE(PACK_EXPANSION_TYPE)(
+    ModuleFile &MF, SmallVectorImpl<uint64_t> &scratch, StringRef blobData) {
+  TypeID patternID;
+  TypeID countID;
+  decls_block::PackExpansionTypeLayout::readRecord(scratch, patternID, countID);
+
+  auto patternTy = MF.getTypeChecked(patternID);
+  if (!patternTy)
+    return patternTy.takeError();
+  auto countTy = MF.getTypeChecked(countID);
+  if (!countTy)
+    return countTy.takeError();
+
+  return PackExpansionType::get(patternTy.get(), countTy.get());
+}
+
+Expected<Type> DESERIALIZE_TYPE(PACK_TYPE)(
+    ModuleFile &MF, SmallVectorImpl<uint64_t> &scratch, StringRef blobData) {
+  // The pack record itself is empty. Read all trailing elements.
+  SmallVector<Type, 8> elements;
+  while (true) {
+    llvm::BitstreamEntry entry =
+        MF.fatalIfUnexpected(MF.DeclTypeCursor.advance(AF_DontPopBlockAtEnd));
+    if (entry.Kind != llvm::BitstreamEntry::Record)
+      break;
+
+    scratch.clear();
+    unsigned recordID = MF.fatalIfUnexpected(
+        MF.DeclTypeCursor.readRecord(entry.ID, scratch, &blobData));
+    if (recordID != decls_block::PACK_TYPE_ELT)
+      break;
+
+    TypeID typeID;
+    decls_block::PackTypeEltLayout::readRecord(scratch, typeID);
+
+    auto elementTy = MF.getTypeChecked(typeID);
+    if (!elementTy)
+      return elementTy.takeError();
+
+    elements.push_back(elementTy.get());
+  }
+
+  return PackType::get(MF.getContext(), elements);
+}
+
 Expected<Type> DESERIALIZE_TYPE(ERROR_TYPE)(ModuleFile &MF,
                                             SmallVectorImpl<uint64_t> &scratch,
                                             StringRef blobData) {

lib/Serialization/ModuleFormat.h

@@ -1272,6 +1272,21 @@ namespace decls_block {
     TypeIDField  // parent
   );
 
+  TYPE_LAYOUT(PackExpansionTypeLayout,
+    PACK_EXPANSION_TYPE,
+    TypeIDField, // pattern type
+    TypeIDField  // count type
+  );
+
+  TYPE_LAYOUT(PackTypeLayout,
+    PACK_TYPE
+  );
+
+  using PackTypeEltLayout = BCRecordLayout<
+    PACK_TYPE_ELT,
+    TypeIDField         // type
+  >;
+
   using TypeAliasLayout = BCRecordLayout<
     TYPE_ALIAS_DECL,
     IdentifierIDField, // name

lib/Serialization/Serialization.cpp

@@ -4611,16 +4611,25 @@ class Serializer::TypeSerializer : public TypeVisitor<TypeSerializer> {
                        S.addTypeRef(wrappedTy));
   }
 
-  void visitPackType(const PackType *pack) {
+  void visitPackExpansionType(const PackExpansionType *expansionTy) {
     using namespace decls_block;
-//    serializeSimpleWrapper<ParenTypeLayout>(parenTy->getUnderlyingType());
-    llvm_unreachable("Unimplemented!");
+    unsigned abbrCode = S.DeclTypeAbbrCodes[PackExpansionTypeLayout::Code];
+    PackExpansionTypeLayout::emitRecord(S.Out, S.ScratchRecord, abbrCode,
+                                        S.addTypeRef(expansionTy->getPatternType()),
+                                        S.addTypeRef(expansionTy->getCountType()));
   }
 
-  void visitPackExpansionType(const PackExpansionType *pack) {
+  void visitPackType(const PackType *packTy) {
     using namespace decls_block;
-//    serializeSimpleWrapper<ParenTypeLayout>(parenTy->getUnderlyingType());
-    llvm_unreachable("Unimplemented!");
+    unsigned abbrCode = S.DeclTypeAbbrCodes[PackTypeLayout::Code];
+    TupleTypeLayout::emitRecord(S.Out, S.ScratchRecord, abbrCode);
+
+    abbrCode = S.DeclTypeAbbrCodes[PackTypeEltLayout::Code];
+    for (auto elt : packTy->getElementTypes()) {
+      PackTypeEltLayout::emitRecord(
+          S.Out, S.ScratchRecord, abbrCode,
+          S.addTypeRef(elt));
+    }
   }
 
   void visitParenType(const ParenType *parenTy) {
@@ -5161,6 +5170,9 @@ void Serializer::writeAllDeclsAndTypes() {
   registerDeclTypeAbbr<UnboundGenericTypeLayout>();
   registerDeclTypeAbbr<OptionalTypeLayout>();
   registerDeclTypeAbbr<DynamicSelfTypeLayout>();
+  registerDeclTypeAbbr<PackExpansionTypeLayout>();
+  registerDeclTypeAbbr<PackTypeLayout>();
+  registerDeclTypeAbbr<PackTypeEltLayout>();
 
   registerDeclTypeAbbr<ErrorFlagLayout>();
   registerDeclTypeAbbr<ErrorTypeLayout>();