swiftlang · compnerd · Jan 11, 2020
diff --git a/include/swift/ABI/Metadata.h b/include/swift/ABI/Metadata.h
@@ -697,8 +697,6 @@ struct TargetMetadata {
 
   bool satisfiesClassConstraint() const;
 
-  bool isCanonicalStaticallySpecializedGenericMetadata() const;
-
 #if SWIFT_OBJC_INTEROP
   /// Get the ObjC class object for this type if it has one, or return null if
   /// the type is not a class (or not a class with a class object).
@@ -1350,34 +1348,6 @@ struct TargetStructMetadata : public TargetValueMetadata<Runtime> {
     return reinterpret_cast<const uint32_t *>(asWords + offset);
   }
 
-  bool isCanonicalStaticallySpecializedGenericMetadata() const {
-    auto *description = getDescription();
-    if (!description->isGeneric())
-      return false;
-
-    auto *trailingFlags = getTrailingFlags();
-    if (trailingFlags == nullptr)
-      return false;
-
-    return trailingFlags->isCanonicalStaticSpecialization();
-  }
-
-  const MetadataTrailingFlags *getTrailingFlags() const {
-    auto description = getDescription();
-    auto flags = description->getFullGenericContextHeader()
-                     .DefaultInstantiationPattern->PatternFlags;
-    if (!flags.hasTrailingFlags())
-      return nullptr;
-    auto fieldOffset = description->FieldOffsetVectorOffset;
-    auto offset =
-        fieldOffset +
-        // Pad to the nearest pointer.
-        ((description->NumFields * sizeof(uint32_t) + sizeof(void *) - 1) /
-         sizeof(void *));
-    auto asWords = reinterpret_cast<const void *const *>(this);
-    return reinterpret_cast<const MetadataTrailingFlags *>(asWords + offset);
-  }
-
   static constexpr int32_t getGenericArgumentOffset() {
     return sizeof(TargetStructMetadata<Runtime>) / sizeof(StoredPointer);
   }
@@ -3605,7 +3575,7 @@ struct TargetSingletonMetadataInitialization {
   }
 
   /// This method can only be called from the runtime itself. It is defined
-  /// in Metadata.cpp.
+  /// in MetadataCache.h.
   TargetMetadata<Runtime> *allocate(
       const TargetTypeContextDescriptor<Runtime> *description) const;
 };

diff --git a/include/swift/ABI/MetadataValues.h b/include/swift/ABI/MetadataValues.h
@@ -1511,10 +1511,6 @@ class GenericMetadataPatternFlags : public FlagSet<uint32_t> {
     /// Does this pattern have an extra-data pattern?
     HasExtraDataPattern = 0,
 
-    /// Do instances of this pattern have a bitset of flags that occur at the
-    /// end of the metadata, after the extra data if there is any?
-    HasTrailingFlags = 1,
-
     // Class-specific flags.
 
     /// Does this pattern have an immediate-members pattern?
@@ -1539,10 +1535,6 @@ class GenericMetadataPatternFlags : public FlagSet<uint32_t> {
                                 hasExtraDataPattern,
                                 setHasExtraDataPattern)
 
-  FLAGSET_DEFINE_FLAG_ACCESSORS(HasTrailingFlags,
-                                hasTrailingFlags,
-                                setHasTrailingFlags)
-
   FLAGSET_DEFINE_FIELD_ACCESSORS(Value_MetadataKind,
                                  Value_MetadataKind_width,
                                  MetadataKind,
@@ -1675,30 +1667,6 @@ class MetadataRequest : public FlagSet<size_t> {
   }
 };
 
-struct MetadataTrailingFlags : public FlagSet<uint64_t> {
-  enum {
-    /// Whether this metadata is a specialization of a generic metadata pattern
-    /// which was created during compilation.
-    IsStaticSpecialization = 0,
-
-    /// Whether this metadata is a specialization of a generic metadata pattern
-    /// which was created during compilation and made to be canonical by
-    /// modifying the metadata accessor.
-    IsCanonicalStaticSpecialization = 1,
-  };
-
-  explicit MetadataTrailingFlags(uint64_t bits) : FlagSet(bits) {}
-  constexpr MetadataTrailingFlags() {}
-
-  FLAGSET_DEFINE_FLAG_ACCESSORS(IsStaticSpecialization,
-                                isStaticSpecialization,
-                                setIsStaticSpecialization)
-
-  FLAGSET_DEFINE_FLAG_ACCESSORS(IsCanonicalStaticSpecialization,
-                                isCanonicalStaticSpecialization,
-                                setIsCanonicalStaticSpecialization)
-};
-
 /// Flags for Builtin.IntegerLiteral values.
 class IntegerLiteralFlags {
 public:

diff --git a/include/swift/AST/ASTContext.h b/include/swift/AST/ASTContext.h
@@ -614,14 +614,6 @@ class ASTContext final {
   /// swift_getTypeByMangledNameInContextInMetadataState.
   AvailabilityContext getTypesInAbstractMetadataStateAvailability();
 
-  /// Get the runtime availability of support for prespecialized generic 
-  /// metadata.
-  AvailabilityContext getPrespecializedGenericMetadataAvailability();
-
-  /// Get the runtime availability of features introduced in the Swift 5.2
-  /// compiler for the target platform.
-  AvailabilityContext getSwift52Availability();
-
 
   //===--------------------------------------------------------------------===//
   // Diagnostics Helper functions

diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
@@ -2864,7 +2864,7 @@ class GenericTypeDecl : public GenericContext, public TypeDecl {
 /// code. One is formed implicitly when a declaration is written with an opaque
 /// result type, as in:
 ///
-/// func foo() -> some SignedInteger { return 1 }
+/// func foo() -> opaque SignedInteger { return 1 }
 ///
 /// The declared type is a special kind of ArchetypeType representing the
 /// abstracted underlying type.

diff --git a/include/swift/AST/IRGenOptions.h b/include/swift/AST/IRGenOptions.h
@@ -190,10 +190,6 @@ class IRGenOptions {
   /// Passing this flag completely disables this behavior.
   unsigned DisableLegacyTypeInfo : 1;
 
-  /// Create metadata specializations for generic types at statically known type
-  /// arguments.
-  unsigned PrespecializeGenericMetadata : 1;
-
   /// The path to load legacy type layouts from.
   StringRef ReadLegacyTypeInfoPath;
 
@@ -259,9 +255,8 @@ class IRGenOptions {
         EnableAnonymousContextMangledNames(false), ForcePublicLinkage(false),
         LazyInitializeClassMetadata(false),
         LazyInitializeProtocolConformances(false), DisableLegacyTypeInfo(false),
-        PrespecializeGenericMetadata(false), UseIncrementalLLVMCodeGen(true),
-        UseSwiftCall(false), GenerateProfile(false),
-        EnableDynamicReplacementChaining(false),
+        UseIncrementalLLVMCodeGen(true), UseSwiftCall(false),
+        GenerateProfile(false), EnableDynamicReplacementChaining(false),
         DisableRoundTripDebugTypes(false), DisableDebuggerShadowCopies(false),
         CmdArgs(), SanitizeCoverage(llvm::SanitizerCoverageOptions()),
         TypeInfoFilter(TypeInfoDumpFilter::All) {}

diff --git a/include/swift/IRGen/Linking.h b/include/swift/IRGen/Linking.h
@@ -65,7 +65,7 @@ class UniversalLinkageInfo {
   bool shouldAllPrivateDeclsBeVisibleFromOtherFiles() const {
     return HasMultipleIGMs;
   }
-  /// In case of multiple llvm modules, private lazy protocol
+  /// In case of multipe llvm modules, private lazy protocol
   /// witness table accessors could be emitted by two different IGMs during
   /// IRGen into different object files and the linker would complain about
   /// duplicate symbols.

diff --git a/include/swift/Option/FrontendOptions.td b/include/swift/Option/FrontendOptions.td
@@ -644,10 +644,6 @@ def disable_verify_exclusivity : Flag<["-"], "disable-verify-exclusivity">,
 def disable_legacy_type_info : Flag<["-"], "disable-legacy-type-info">,
   HelpText<"Completely disable legacy type layout">;
 
-def prespecialize_generic_metadata : Flag<["-"], "prespecialize-generic-metadata">,
-  HelpText<"Statically specialize metadata for generic types at types that "
-           "are known to be used in source.">;
-
 def read_legacy_type_info_path_EQ : Joined<["-"], "read-legacy-type-info-path=">,
   HelpText<"Read legacy type layout from the given path instead of default path">;
 

diff --git a/lib/AST/Availability.cpp b/lib/AST/Availability.cpp
@@ -239,25 +239,14 @@ AvailabilityContext ASTContext::getSwift51Availability() {
 }
 
 AvailabilityContext ASTContext::getTypesInAbstractMetadataStateAvailability() {
-  return getSwift52Availability();
-}
-
-AvailabilityContext ASTContext::getPrespecializedGenericMetadataAvailability() {
-  return getSwift52Availability();
-}
-
-AvailabilityContext ASTContext::getSwift52Availability() {
   auto target = LangOpts.Target;
 
   if (target.isMacOSX() ) {
     return AvailabilityContext(
         VersionRange::allGTE(llvm::VersionTuple(10, 99, 0)));
-  } else if (target.isiOS()) {
-    return AvailabilityContext(
-        VersionRange::allGTE(llvm::VersionTuple(99, 0, 0)));
-  } else if (target.isWatchOS()) {
+  } else if (target.isiOS() || target.isWatchOS()) {
     return AvailabilityContext(
-        VersionRange::allGTE(llvm::VersionTuple(9, 99, 0)));
+        VersionRange::allGTE(llvm::VersionTuple(9999, 0, 0)));
   } else {
     return AvailabilityContext::alwaysAvailable();
   }

diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
@@ -1245,10 +1245,6 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
     Opts.DisableLegacyTypeInfo = true;
   }
 
-  if (Args.hasArg(OPT_prespecialize_generic_metadata)) {
-    Opts.PrespecializeGenericMetadata = true;
-  }
-
   if (const Arg *A = Args.getLastArg(OPT_read_legacy_type_info_path_EQ)) {
     Opts.ReadLegacyTypeInfoPath = A->getValue();
   }

diff --git a/lib/IRGen/ClassMetadataVisitor.h b/lib/IRGen/ClassMetadataVisitor.h
@@ -204,13 +204,8 @@ class ClassMetadataScanner : public ClassMetadataVisitor<Impl> {
       addPointer();
     }
   }
-  void addGenericArgument(GenericRequirement requirement, ClassDecl *forClass) {
-    addPointer();
-  }
-  void addGenericWitnessTable(GenericRequirement requirement,
-                              ClassDecl *forClass) {
-    addPointer();
-  }
+  void addGenericArgument(ClassDecl *forClass) { addPointer(); }
+  void addGenericWitnessTable(ClassDecl *forClass) { addPointer(); }
   void addPlaceholder(MissingMemberDecl *MMD) {
     for (auto i : range(MMD->getNumberOfVTableEntries())) {
       (void)i;

diff --git a/lib/IRGen/EnumMetadataVisitor.h b/lib/IRGen/EnumMetadataVisitor.h
@@ -82,8 +82,8 @@ class EnumMetadataScanner : public EnumMetadataVisitor<Impl> {
   void addMetadataFlags() { addPointer(); }
   void addValueWitnessTable() { addPointer(); }
   void addNominalTypeDescriptor() { addPointer(); }
-  void addGenericArgument(GenericRequirement requirement) { addPointer(); }
-  void addGenericWitnessTable(GenericRequirement requirement) { addPointer(); }
+  void addGenericArgument() { addPointer(); }
+  void addGenericWitnessTable() { addPointer(); }
   void addPayloadSize() { addPointer(); }
   void noteStartOfTypeSpecificMembers() {}
 

diff --git a/lib/IRGen/GenDecl.cpp b/lib/IRGen/GenDecl.cpp
@@ -1129,7 +1129,6 @@ void IRGenerator::emitTypeMetadataRecords() {
 /// else) that we require.
 void IRGenerator::emitLazyDefinitions() {
   while (!LazyTypeMetadata.empty() ||
-         !LazySpecializedTypeMetadataRecords.empty() ||
          !LazyTypeContextDescriptors.empty() ||
          !LazyOpaqueTypeDescriptors.empty() ||
          !LazyFieldDescriptors.empty() ||
@@ -1146,12 +1145,6 @@ void IRGenerator::emitLazyDefinitions() {
       CurrentIGMPtr IGM = getGenModule(type->getDeclContext());
       emitLazyTypeMetadata(*IGM.get(), type);
     }
-    while (!LazySpecializedTypeMetadataRecords.empty()) {
-      CanType type = LazySpecializedTypeMetadataRecords.pop_back_val();
-      auto *nominal = type->getNominalOrBoundGenericNominal();
-      CurrentIGMPtr IGM = getGenModule(nominal->getDeclContext());
-      emitLazySpecializedGenericTypeMetadata(*IGM.get(), type);
-    }
     while (!LazyTypeContextDescriptors.empty()) {
       NominalTypeDecl *type = LazyTypeContextDescriptors.pop_back_val();
       auto &entry = LazyTypeGlobals.find(type)->second;
@@ -1192,12 +1185,6 @@ void IRGenerator::emitLazyDefinitions() {
     }
   }
 
-  while (!LazyMetadataAccessors.empty()) {
-    NominalTypeDecl *nominal = LazyMetadataAccessors.pop_back_val();
-    CurrentIGMPtr IGM = getGenModule(nominal->getDeclContext());
-    emitLazyMetadataAccessor(*IGM.get(), nominal);
-  }
-
   FinishedEmittingLazyDefinitions = true;
 }
 
@@ -1375,18 +1362,6 @@ void IRGenerator::noteUseOfFieldDescriptor(NominalTypeDecl *type) {
   LazyFieldDescriptors.push_back(type);
 }
 
-void IRGenerator::noteUseOfSpecializedGenericTypeMetadata(CanType type) {
-  auto key = type->getAnyNominal();
-  assert(key);
-  auto &enqueuedSpecializedTypes = this->SpecializationsForGenericTypes[key];
-  if (llvm::all_of(enqueuedSpecializedTypes,
-                   [&](CanType enqueued) { return enqueued != type; })) {
-    assert(!FinishedEmittingLazyDefinitions);
-    this->LazySpecializedTypeMetadataRecords.push_back(type);
-    enqueuedSpecializedTypes.push_back(type);
-  }
-}
-
 void IRGenerator::noteUseOfOpaqueTypeDescriptor(OpaqueTypeDecl *opaque) {
   if (!opaque)
     return;
@@ -3671,11 +3646,8 @@ llvm::GlobalValue *IRGenModule::defineTypeMetadata(CanType concreteType,
   if (nominal)
     addRuntimeResolvableType(nominal);
 
-  // Don't define the alias for foreign type metadata or prespecialized generic
-  // metadata, since neither is ABI.
-  if ((nominal && requiresForeignTypeMetadata(nominal)) ||
-      (concreteType->getAnyGeneric() &&
-       concreteType->getAnyGeneric()->isGenericContext()))
+  // Don't define the alias for foreign type metadata, since it's not ABI.
+  if (nominal && requiresForeignTypeMetadata(nominal))
     return var;
 
   // For concrete metadata, declare the alias to its address point.
@@ -3710,13 +3682,9 @@ ConstantReference IRGenModule::getAddrOfTypeMetadata(CanType concreteType,
 
   llvm::Type *defaultVarTy;
   unsigned adjustmentIndex;
-
-  bool fullMetadata = (nominal && requiresForeignTypeMetadata(nominal)) ||
-                      (concreteType->getAnyGeneric() &&
-                       concreteType->getAnyGeneric()->isGenericContext());
-
+
   // Foreign classes reference the full metadata with a GEP.
-  if (fullMetadata) {
+  if (nominal && requiresForeignTypeMetadata(nominal)) {
     defaultVarTy = FullTypeMetadataStructTy;
     adjustmentIndex = MetadataAdjustmentIndex::ValueType;
   // The symbol for other nominal type metadata is generated at the address
@@ -3741,18 +3709,10 @@ ConstantReference IRGenModule::getAddrOfTypeMetadata(CanType concreteType,
     IRGen.noteUseOfTypeMetadata(nominal);
   }
 
-  if (shouldPrespecializeGenericMetadata()) {
-    if (auto nominal = concreteType->getAnyNominal()) {
-      if (nominal->isGenericContext()) {
-        IRGen.noteUseOfSpecializedGenericTypeMetadata(concreteType);
-      }
-    }
-  }
-
   Optional<LinkEntity> entity;
   DebugTypeInfo DbgTy;
 
-  if (fullMetadata) {
+  if (nominal && requiresForeignTypeMetadata(nominal)) {
     entity = LinkEntity::forTypeMetadata(concreteType,
                                          TypeMetadataAddress::FullMetadata);
     DbgTy = DebugTypeInfo::getMetadata(MetatypeType::get(concreteType),
@@ -4069,6 +4029,10 @@ Optional<llvm::Function*> IRGenModule::getAddrOfIVarInitDestroy(
 llvm::Function *IRGenModule::getAddrOfValueWitness(CanType abstractType,
                                                    ValueWitness index,
                                                 ForDefinition_t forDefinition) {
+  // We shouldn't emit value witness symbols for generic type instances.
+  assert(!isa<BoundGenericType>(abstractType) &&
+         "emitting value witness for generic type instance?!");
+
   LinkEntity entity = LinkEntity::forValueWitness(abstractType, index);
 
   llvm::Function *&entry = GlobalFuncs[entity];