Merge pull request #61856 from slavapestov/remove-abstract-type-param-decl

Remove AbstractTypeParamDecl

Author: slavapestov

include/swift/AST/Decl.h

@@ -499,9 +499,8 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
   );
 
   SWIFT_INLINE_BITFIELD_EMPTY(TypeDecl, ValueDecl);
-  SWIFT_INLINE_BITFIELD_EMPTY(AbstractTypeParamDecl, TypeDecl);
 
-  SWIFT_INLINE_BITFIELD_FULL(GenericTypeParamDecl, AbstractTypeParamDecl, 16+16+1+1,
+  SWIFT_INLINE_BITFIELD_FULL(GenericTypeParamDecl, TypeDecl, 16+16+1+1,
     : NumPadBits,
 
     Depth : 16,
@@ -3182,29 +3181,6 @@ class TypeAliasDecl : public GenericTypeDecl {
   }
 };
 
-/// Abstract class describing generic type parameters and associated types,
-/// whose common purpose is to anchor the abstract type parameter and specify
-/// requirements for any corresponding type argument.
-class AbstractTypeParamDecl : public TypeDecl {
-protected:
-  AbstractTypeParamDecl(DeclKind kind, DeclContext *dc, Identifier name,
-                        SourceLoc NameLoc)
-    : TypeDecl(kind, dc, name, NameLoc, { }) { }
-
-public:
-  /// Return the superclass of the generic parameter.
-  Type getSuperclass() const;
-
-  /// Retrieve the set of protocols to which this abstract type
-  /// parameter conforms.
-  ArrayRef<ProtocolDecl *> getConformingProtocols() const;
-
-  static bool classof(const Decl *D) {
-    return D->getKind() >= DeclKind::First_AbstractTypeParamDecl &&
-           D->getKind() <= DeclKind::Last_AbstractTypeParamDecl;
-  }
-};
-
 /// A declaration of a generic type parameter.
 ///
 /// A generic type parameter introduces a new, named type parameter along
@@ -3219,7 +3195,7 @@ class AbstractTypeParamDecl : public TypeDecl {
 /// func min<T : Comparable>(x : T, y : T) -> T { ... }
 /// \endcode
 class GenericTypeParamDecl final
-    : public AbstractTypeParamDecl,
+    : public TypeDecl,
       private llvm::TrailingObjects<GenericTypeParamDecl, TypeRepr *,
                                     SourceLoc> {
   friend TrailingObjects;
@@ -3446,7 +3422,7 @@ class GenericTypeParamDecl final
 ///   func getNext() -> Element?
 /// }
 /// \endcode
-class AssociatedTypeDecl : public AbstractTypeParamDecl {
+class AssociatedTypeDecl : public TypeDecl {
   /// The location of the initial keyword.
   SourceLoc KeywordLoc;
 
@@ -3510,7 +3486,7 @@ class AssociatedTypeDecl : public AbstractTypeParamDecl {
   /// Retrieve the (first) overridden associated type declaration, if any.
   AssociatedTypeDecl *getOverriddenDecl() const {
     return cast_or_null<AssociatedTypeDecl>(
-                                   AbstractTypeParamDecl::getOverriddenDecl());
+        TypeDecl::getOverriddenDecl());
   }
 
   /// Retrieve the set of associated types overridden by this associated

include/swift/AST/DeclNodes.def

@@ -156,10 +156,8 @@ ABSTRACT_DECL(Value, Decl)
       GENERIC_VALUE_DECL(OpaqueType, GenericTypeDecl)
       GENERIC_VALUE_DECL(TypeAlias, GenericTypeDecl)
       DECL_RANGE(GenericType, Enum, TypeAlias)
-    ABSTRACT_DECL(AbstractTypeParam, TypeDecl)
-      VALUE_DECL(GenericTypeParam, AbstractTypeParamDecl)
-      VALUE_DECL(AssociatedType, AbstractTypeParamDecl)
-      DECL_RANGE(AbstractTypeParam, GenericTypeParam, AssociatedType)
+    VALUE_DECL(GenericTypeParam, TypeDecl)
+    VALUE_DECL(AssociatedType, TypeDecl)
     CONTEXT_VALUE_DECL(Module, TypeDecl)
     DECL_RANGE(Type, Enum, Module)
   ABSTRACT_DECL(AbstractStorage, ValueDecl)

lib/AST/ASTDumper.cpp

@@ -648,19 +648,14 @@ namespace {
       PrintWithColorRAII(OS, ParenthesisColor) << ')';
     }
 
-    void printAbstractTypeParamCommon(AbstractTypeParamDecl *decl,
-                                      const char *name) {
-      printCommon(decl, name);
-    }
-
     void visitGenericTypeParamDecl(GenericTypeParamDecl *decl) {
-      printAbstractTypeParamCommon(decl, "generic_type_param");
+      printCommon(decl, "generic_type_param");
       OS << " depth=" << decl->getDepth() << " index=" << decl->getIndex();
       PrintWithColorRAII(OS, ParenthesisColor) << ')';
     }
 
     void visitAssociatedTypeDecl(AssociatedTypeDecl *decl) {
-      printAbstractTypeParamCommon(decl, "associated_type_decl");
+      printCommon(decl, "associated_type_decl");
       if (auto defaultDef = decl->getDefaultDefinitionType()) {
         OS << " default=";
         defaultDef.print(OS);

lib/AST/ASTPrinter.cpp

@@ -6559,16 +6559,13 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
 
       // Print based on the type.
       Printer << "some ";
-      if (!decl->getConformingProtocols().empty()) {
-        llvm::interleave(decl->getConformingProtocols(), Printer, [&](ProtocolDecl *proto){
-          if (auto printType = proto->getDeclaredType())
-            printType->print(Printer, Options);
-          else
-            Printer << proto->getNameStr();
-        }, " & ");
-      } else {
-        Printer << "Any";
-      }
+      auto archetypeType = decl->getDeclContext()->mapTypeIntoContext(
+          decl->getDeclaredInterfaceType())->castTo<ArchetypeType>();
+      auto constraintType = archetypeType->getExistentialType();
+      if (auto *existentialType = constraintType->getAs<ExistentialType>())
+        constraintType = existentialType->getConstraintType();
+
+      constraintType->print(Printer, Options);
       return;
     }
 

lib/AST/ASTWalker.cpp

@@ -275,23 +275,29 @@ class Traversal : public ASTVisitor<Traversal, Expr*, Stmt*,
     return false;
   }
 
-  bool visitAbstractTypeParamDecl(AbstractTypeParamDecl *TPD) {
-    for (const auto &Inherit: TPD->getInherited()) {
+  bool visitGenericTypeParamDecl(GenericTypeParamDecl *GTPD) {
+    for (const auto &Inherit: GTPD->getInherited()) {
       if (auto *const TyR = Inherit.getTypeRepr())
         if (doIt(TyR))
           return true;
     }
+    return false;
+  }
 
-    if (const auto ATD = dyn_cast<AssociatedTypeDecl>(TPD)) {
-      if (const auto DefaultTy = ATD->getDefaultDefinitionTypeRepr())
-        if (doIt(DefaultTy))
+  bool visitAssociatedTypeDecl(AssociatedTypeDecl *ATD) {
+    for (const auto &Inherit: ATD->getInherited()) {
+      if (auto *const TyR = Inherit.getTypeRepr())
+        if (doIt(TyR))
           return true;
+    }
+    if (const auto DefaultTy = ATD->getDefaultDefinitionTypeRepr())
+      if (doIt(DefaultTy))
+        return true;
 
-      if (auto *WhereClause = ATD->getTrailingWhereClause()) {
-        for (auto &Req: WhereClause->getRequirements()) {
-          if (doIt(Req))
-            return true;
-        }
+    if (auto *WhereClause = ATD->getTrailingWhereClause()) {
+      for (auto &Req: WhereClause->getRequirements()) {
+        if (doIt(Req))
+          return true;
       }
     }
     return false;

lib/AST/Decl.cpp

@@ -547,7 +547,7 @@ bool Decl::canHaveComment() const {
   return !this->hasClangNode() &&
          (isa<ValueDecl>(this) || isa<ExtensionDecl>(this)) &&
          !isa<ParamDecl>(this) &&
-         (!isa<AbstractTypeParamDecl>(this) || isa<AssociatedTypeDecl>(this));
+         !isa<GenericTypeParamDecl>(this);
 }
 
 ModuleDecl *Decl::getModuleContext() const {
@@ -4623,36 +4623,11 @@ Type TypeAliasDecl::getStructuralType() const {
   return ErrorType::get(ctx);
 }
 
-Type AbstractTypeParamDecl::getSuperclass() const {
-  auto *genericEnv = getDeclContext()->getGenericEnvironmentOfContext();
-  assert(genericEnv != nullptr && "Too much circularity");
-
-  auto contextTy = genericEnv->mapTypeIntoContext(getDeclaredInterfaceType());
-  if (auto *archetype = contextTy->getAs<ArchetypeType>())
-    return archetype->getSuperclass();
-
-  // FIXME: Assert that this is never queried.
-  return nullptr;
-}
-
-ArrayRef<ProtocolDecl *>
-AbstractTypeParamDecl::getConformingProtocols() const {
-  auto *genericEnv = getDeclContext()->getGenericEnvironmentOfContext();
-  assert(genericEnv != nullptr && "Too much circularity");
-
-  auto contextTy = genericEnv->mapTypeIntoContext(getDeclaredInterfaceType());
-  if (auto *archetype = contextTy->getAs<ArchetypeType>())
-    return archetype->getConformsTo();
-
-  // FIXME: Assert that this is never queried.
-  return { };
-}
-
 GenericTypeParamDecl::GenericTypeParamDecl(
     DeclContext *dc, Identifier name, SourceLoc nameLoc, SourceLoc ellipsisLoc,
     unsigned depth, unsigned index, bool isParameterPack, bool isOpaqueType,
     TypeRepr *opaqueTypeRepr)
-    : AbstractTypeParamDecl(DeclKind::GenericTypeParam, dc, name, nameLoc) {
+    : TypeDecl(DeclKind::GenericTypeParam, dc, name, nameLoc, { }) {
   assert(!(ellipsisLoc && !isParameterPack) &&
          "Ellipsis always means type parameter pack");
 
@@ -4736,7 +4711,7 @@ AssociatedTypeDecl::AssociatedTypeDecl(DeclContext *dc, SourceLoc keywordLoc,
                                        Identifier name, SourceLoc nameLoc,
                                        TypeRepr *defaultDefinition,
                                        TrailingWhereClause *trailingWhere)
-    : AbstractTypeParamDecl(DeclKind::AssociatedType, dc, name, nameLoc),
+    : TypeDecl(DeclKind::AssociatedType, dc, name, nameLoc, { }),
       KeywordLoc(keywordLoc), DefaultDefinition(defaultDefinition),
       TrailingWhere(trailingWhere) {}
 
@@ -4745,7 +4720,7 @@ AssociatedTypeDecl::AssociatedTypeDecl(DeclContext *dc, SourceLoc keywordLoc,
                                        TrailingWhereClause *trailingWhere,
                                        LazyMemberLoader *definitionResolver,
                                        uint64_t resolverData)
-    : AbstractTypeParamDecl(DeclKind::AssociatedType, dc, name, nameLoc),
+    : TypeDecl(DeclKind::AssociatedType, dc, name, nameLoc, { }),
       KeywordLoc(keywordLoc), DefaultDefinition(nullptr),
       TrailingWhere(trailingWhere), Resolver(definitionResolver),
       ResolverContextData(resolverData) {
@@ -4781,7 +4756,7 @@ AssociatedTypeDecl::getOverriddenDecls() const {
   if (auto cached = request.getCachedResult())
     overridden = std::move(*cached);
   else
-    overridden = AbstractTypeParamDecl::getOverriddenDecls();
+    overridden = TypeDecl::getOverriddenDecls();
 
   llvm::TinyPtrVector<AssociatedTypeDecl *> assocTypes;
   for (auto decl : overridden) {
@@ -4809,7 +4784,7 @@ static AssociatedTypeDecl *getAssociatedTypeAnchor(
     auto anchor = getAssociatedTypeAnchor(assocType, searched);
     if (!anchor)
       continue;
-    if (!bestAnchor || AbstractTypeParamDecl::compare(anchor, bestAnchor) < 0)
+    if (!bestAnchor || TypeDecl::compare(anchor, bestAnchor) < 0)
       bestAnchor = anchor;
   }
 

lib/AST/NameLookup.cpp

@@ -2300,7 +2300,8 @@ resolveTypeDeclsToNominal(Evaluator &evaluator,
     }
 
     // Make sure we didn't miss some interesting kind of type declaration.
-    assert(isa<AbstractTypeParamDecl>(typeDecl));
+    assert(isa<GenericTypeParamDecl>(typeDecl) ||
+           isa<AssociatedTypeDecl>(typeDecl));
   }
 
   return nominalDecls;

lib/ClangImporter/ImportType.cpp

@@ -24,6 +24,7 @@
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/DiagnosticsClangImporter.h"
 #include "swift/AST/ExistentialLayout.h"
+#include "swift/AST/GenericEnvironment.h"
 #include "swift/AST/GenericParamList.h"
 #include "swift/AST/GenericSignature.h"
 #include "swift/AST/Module.h"
@@ -1071,29 +1072,13 @@ namespace {
               importedTypeArgs.push_back(importedTypeArg);
             }
           } else {
-            for (auto typeParam : imported->getGenericParams()->getParams()) {
-              if (typeParam->getSuperclass() &&
-                  typeParam->getConformingProtocols().empty()) {
-                importedTypeArgs.push_back(typeParam->getSuperclass());
-                continue;
-              }
-
-              SmallVector<Type, 4> memberTypes;
-
-              if (auto superclassType = typeParam->getSuperclass())
-                memberTypes.push_back(superclassType);
+            auto *genericEnv = imported->getGenericEnvironment();
 
-              for (auto protocolDecl : typeParam->getConformingProtocols())
-                memberTypes.push_back(protocolDecl->getDeclaredInterfaceType());
-
-              bool hasExplicitAnyObject = false;
-              if (memberTypes.empty())
-                hasExplicitAnyObject = true;
-
-              Type importedTypeArg = ExistentialType::get(
-                  ProtocolCompositionType::get(
-                      Impl.SwiftContext, memberTypes,
-                      hasExplicitAnyObject));
+            for (auto typeParam : imported->getGenericParams()->getParams()) {
+              Type importedTypeArg = genericEnv->mapTypeIntoContext(
+                  typeParam->getDeclaredInterfaceType())
+                  ->castTo<ArchetypeType>()
+                  ->getExistentialType();
               importedTypeArgs.push_back(importedTypeArg);
             }
           }

lib/IDE/CodeCompletionResultBuilder.cpp

@@ -27,7 +27,7 @@ using namespace swift::ide;
 
 static bool shouldCopyAssociatedUSRForDecl(const ValueDecl *VD) {
   // Avoid trying to generate a USR for some declaration types.
-  if (isa<AbstractTypeParamDecl>(VD) && !isa<AssociatedTypeDecl>(VD))
+  if (isa<GenericTypeParamDecl>(VD))
     return false;
   if (isa<ParamDecl>(VD))
     return false;

lib/PrintAsClang/ModuleContentsWriter.cpp

@@ -314,8 +314,10 @@ class ModuleWriter {
       return;
     } else if (auto ED = dyn_cast<EnumDecl>(TD)) {
       forwardDeclare(ED);
-    } else if (isa<AbstractTypeParamDecl>(TD)) {
-      llvm_unreachable("should not see type params here");
+    } else if (isa<GenericTypeParamDecl>(TD)) {
+      llvm_unreachable("should not see generic parameters here");
+    } else if (isa<AssociatedTypeDecl>(TD)) {
+      llvm_unreachable("should not see associated types here");
     } else if (isa<StructDecl>(TD) &&
                TD->getModuleContext()->isStdlibModule()) {
       // stdlib has some @_cdecl functions with structs.