Merge pull request swiftlang#33747 from DougGregor/generalize-get-emitted-members

[AST] Generalize and rename ClassDecl::getEmittedMembers()

Author: DougGregor

include/swift/AST/Decl.h

@@ -3886,7 +3886,7 @@ class ClassDecl final : public NominalTypeDecl {
 
   friend class SuperclassDeclRequest;
   friend class SuperclassTypeRequest;
-  friend class EmittedMembersRequest;
+  friend class SemanticMembersRequest;
   friend class HasMissingDesignatedInitializersRequest;
   friend class InheritsSuperclassInitializersRequest;
 
@@ -4074,10 +4074,6 @@ class ClassDecl final : public NominalTypeDecl {
   /// Record the presence of an @objc method with the given selector.
   void recordObjCMethod(AbstractFunctionDecl *method, ObjCSelector selector);
 
-  /// Get all the members of this class, synthesizing any implicit members
-  /// that appear in the vtable if needed.
-  ArrayRef<Decl *> getEmittedMembers() const;
-
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) {
     return D->getKind() == DeclKind::Class;

include/swift/AST/DeclContext.h

@@ -783,6 +783,16 @@ class IterableDeclContext {
   /// Retrieve the set of members in this context.
   DeclRange getMembers() const;
 
+  /// Get the members that were syntactically present in the source code,
+  /// and will not contain any members that are implicitly synthesized by
+  /// the implementation.
+  ArrayRef<Decl *> getParsedMembers() const;
+
+  /// Get all the members that are semantically within this context,
+  /// including any implicitly-synthesized members.
+  /// The resulting list of members will be stable across translation units.
+  ArrayRef<Decl *> getSemanticMembers() const;
+
   /// Retrieve the set of members in this context without loading any from the
   /// associated lazy loader; this should only be used as part of implementing
   /// abstractions on top of member loading, such as a name lookup table.

include/swift/AST/TypeCheckRequests.h

@@ -1080,9 +1080,9 @@ class SynthesizeAccessorRequest :
   void cacheResult(AccessorDecl *value) const;
 };
 
-class EmittedMembersRequest :
-    public SimpleRequest<EmittedMembersRequest,
-                         ArrayRef<Decl *>(ClassDecl *),
+class SemanticMembersRequest :
+    public SimpleRequest<SemanticMembersRequest,
+                         ArrayRef<Decl *>(IterableDeclContext *),
                          RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -1092,7 +1092,7 @@ class EmittedMembersRequest :
 
   // Evaluation.
   ArrayRef<Decl *>
-  evaluate(Evaluator &evaluator, ClassDecl *classDecl) const;
+  evaluate(Evaluator &evaluator, IterableDeclContext *idc) const;
 
 public:
   bool isCached() const { return true; }

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -65,8 +65,8 @@ SWIFT_REQUEST(TypeChecker, TypeEraserHasViableInitRequest,
 SWIFT_REQUEST(TypeChecker, DynamicallyReplacedDeclRequest,
               ValueDecl *(ValueDecl *),
               Cached, NoLocationInfo)
-SWIFT_REQUEST(TypeChecker, EmittedMembersRequest, ArrayRef<Decl *>(ClassDecl *),
-              Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, SemanticMembersRequest,
+              ArrayRef<Decl *>(IterableDeclContext *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, EnumRawValuesRequest,
               evaluator::SideEffect (EnumDecl *, TypeResolutionStage),
               SeparatelyCached, NoLocationInfo)

include/swift/SIL/SILVTableVisitor.h

@@ -148,7 +148,7 @@ template <class T> class SILVTableVisitor {
     if (!theClass->hasKnownSwiftImplementation())
       return;
 
-    for (auto member : theClass->getEmittedMembers())
+    for (auto member : theClass->getSemanticMembers())
       maybeAddMember(member);
   }
 };

lib/AST/Decl.cpp

@@ -4181,13 +4181,6 @@ DestructorDecl *ClassDecl::getDestructor() const {
                            nullptr);
 }
 
-ArrayRef<Decl *> ClassDecl::getEmittedMembers() const {
-  ASTContext &ctx = getASTContext();
-  return evaluateOrDefault(ctx.evaluator,
-                           EmittedMembersRequest{const_cast<ClassDecl *>(this)},
-                           ArrayRef<Decl *>());
-}
-
 /// Synthesizer callback for an empty implicit function body.
 static std::pair<BraceStmt *, bool>
 synthesizeEmptyFunctionBody(AbstractFunctionDecl *afd, void *context) {

lib/AST/DeclContext.cpp

@@ -793,6 +793,23 @@ DeclRange IterableDeclContext::getMembers() const {
   return getCurrentMembersWithoutLoading();
 }
 
+ArrayRef<Decl *> IterableDeclContext::getParsedMembers() const {
+  ASTContext &ctx = getASTContext();
+  auto mutableThis = const_cast<IterableDeclContext *>(this);
+  return evaluateOrDefault(
+      ctx.evaluator, ParseMembersRequest{mutableThis},
+      FingerprintAndMembers())
+    .members;
+}
+
+ArrayRef<Decl *> IterableDeclContext::getSemanticMembers() const {
+  ASTContext &ctx = getASTContext();
+  return evaluateOrDefault(
+      ctx.evaluator,
+      SemanticMembersRequest{const_cast<IterableDeclContext *>(this)},
+      ArrayRef<Decl *>());
+}
+
 /// Add a member to this context.
 void IterableDeclContext::addMember(Decl *member, Decl *Hint) {
   // Add the member to the list of declarations without notification.
@@ -891,10 +908,7 @@ void IterableDeclContext::loadAllMembers() const {
     // members to this context, this call is important for recording the
     // dependency edge.
     auto mutableThis = const_cast<IterableDeclContext *>(this);
-    auto members =
-        evaluateOrDefault(ctx.evaluator, ParseMembersRequest{mutableThis},
-                          FingerprintAndMembers())
-            .members;
+    auto members = getParsedMembers();
 
     // If we haven't already done so, add these members to this context.
     if (!AddedParsedMembers) {

lib/Parse/ParseRequests.cpp

@@ -49,15 +49,29 @@ void swift::simple_display(llvm::raw_ostream &out,
 FingerprintAndMembers
 ParseMembersRequest::evaluate(Evaluator &evaluator,
                               IterableDeclContext *idc) const {
-  SourceFile &sf = *idc->getAsGenericContext()->getParentSourceFile();
-  unsigned bufferID = *sf.getBufferID();
+  SourceFile *sf = idc->getAsGenericContext()->getParentSourceFile();
+  ASTContext &ctx = idc->getDecl()->getASTContext();
+  if (!sf) {
+    // If there is no parent source file, this is a deserialized or synthesized
+    // declaration context, in which case `getMembers()` has all of the members.
+    // Filter out the implicitly-generated ones.
+    SmallVector<Decl *, 4> members;
+    for (auto decl : idc->getMembers()) {
+      if (!decl->isImplicit()) {
+        members.push_back(decl);
+      }
+    }
+
+    return FingerprintAndMembers{None, ctx.AllocateCopy(members)};
+  }
+
+  unsigned bufferID = *sf->getBufferID();
 
   // Lexer diaganostics have been emitted during skipping, so we disable lexer's
   // diagnostic engine here.
-  Parser parser(bufferID, sf, /*No Lexer Diags*/nullptr, nullptr, nullptr);
+  Parser parser(bufferID, *sf, /*No Lexer Diags*/nullptr, nullptr, nullptr);
   // Disable libSyntax creation in the delayed parsing.
   parser.SyntaxContext->disable();
-  ASTContext &ctx = idc->getDecl()->getASTContext();
   auto declsAndHash = parser.parseDeclListDelayed(idc);
   FingerprintAndMembers fingerprintAndMembers = {declsAndHash.second,
                                                  declsAndHash.first};

lib/SILGen/SILGenType.cpp

@@ -1038,7 +1038,7 @@ class SILGenType : public TypeMemberVisitor<SILGenType> {
 
     // Build a vtable if this is a class.
     if (auto theClass = dyn_cast<ClassDecl>(theType)) {
-      for (Decl *member : theClass->getEmittedMembers())
+      for (Decl *member : theClass->getSemanticMembers())
         visit(member);
 
       SILGenVTable genVTable(SGM, theClass);

lib/Sema/TypeCheckDecl.cpp

@@ -2506,60 +2506,52 @@ struct SortedFuncList {
 } // end namespace
 
 ArrayRef<Decl *>
-EmittedMembersRequest::evaluate(Evaluator &evaluator,
-                                ClassDecl *CD) const {
-  auto &Context = CD->getASTContext();
+SemanticMembersRequest::evaluate(Evaluator &evaluator,
+                                IterableDeclContext *idc) const {
+  auto dc = cast<DeclContext>(idc->getDecl());
+  auto &Context = dc->getASTContext();
   SmallVector<Decl *, 8> result;
 
-  if (!CD->getParentSourceFile()) {
-    auto members = CD->getMembers();
+  if (!dc->getParentSourceFile()) {
+    auto members = idc->getMembers();
     result.append(members.begin(), members.end());
     return Context.AllocateCopy(result);
   }
 
-  // We need to add implicit initializers because they
-  // affect vtable layout.
-  TypeChecker::addImplicitConstructors(CD);
+  auto nominal = dyn_cast<NominalTypeDecl>(idc);
 
-  auto forceConformance = [&](ProtocolDecl *protocol) {
-    auto ref = CD->getParentModule()->lookupConformance(
-        CD->getDeclaredInterfaceType(), protocol);
-    if (ref.isInvalid()) {
-      return;
-    }
+  if (nominal) {
+    // We need to add implicit initializers because they
+    // affect vtable layout.
+    TypeChecker::addImplicitConstructors(nominal);
+  }
 
-    auto conformance = ref.getConcrete();
-    if (conformance->getDeclContext() == CD &&
-        conformance->getState() == ProtocolConformanceState::Incomplete) {
+  // Force any derivable conformances in this context. This ensures that any
+  // synthesized members will approach in the member list.
+  for (auto conformance : idc->getLocalConformances()) {
+    if (conformance->getState() == ProtocolConformanceState::Incomplete &&
+        conformance->getProtocol()->getKnownDerivableProtocolKind())
       TypeChecker::checkConformance(conformance->getRootNormalConformance());
-    }
-  };
+  }
 
-  // If the class is Encodable, Decodable or Hashable, force those
-  // conformances to ensure that the synthesized members appear in the vtable.
-  //
-  // FIXME: Generalize this to other protocols for which
-  // we can derive conformances.
-  forceConformance(Context.getProtocol(KnownProtocolKind::Decodable));
-  forceConformance(Context.getProtocol(KnownProtocolKind::Encodable));
-  forceConformance(Context.getProtocol(KnownProtocolKind::Hashable));
-  forceConformance(Context.getProtocol(KnownProtocolKind::Differentiable));
-
-  // If the class conforms to Encodable or Decodable, even via an extension,
+  // If the type conforms to Encodable or Decodable, even via an extension,
   // the CodingKeys enum is synthesized as a member of the type itself.
   // Force it into existence.
-  (void) evaluateOrDefault(Context.evaluator,
-                           ResolveImplicitMemberRequest{CD,
-                                      ImplicitMemberAction::ResolveCodingKeys},
-                           {});
+  if (nominal) {
+    (void) evaluateOrDefault(Context.evaluator,
+                             ResolveImplicitMemberRequest{nominal,
+                                        ImplicitMemberAction::ResolveCodingKeys},
+                             {});
+  }
 
-  // If the class has a @main attribute, we need to force synthesis of the
+  // If the decl has a @main attribute, we need to force synthesis of the
   // $main function.
-  (void) evaluateOrDefault(Context.evaluator,
-                           SynthesizeMainFunctionRequest{CD},
-                           nullptr);
+  (void) evaluateOrDefault(
+      Context.evaluator,
+      SynthesizeMainFunctionRequest{const_cast<Decl *>(idc->getDecl())},
+      nullptr);
 
-  for (auto *member : CD->getMembers()) {
+  for (auto *member : idc->getMembers()) {
     if (auto *var = dyn_cast<VarDecl>(member)) {
       // The projected storage wrapper ($foo) might have dynamically-dispatched
       // accessors, so force them to be synthesized.
@@ -2570,7 +2562,7 @@ EmittedMembersRequest::evaluate(Evaluator &evaluator,
 
   SortedFuncList synthesizedMembers;
 
-  for (auto *member : CD->getMembers()) {
+  for (auto *member : idc->getMembers()) {
     if (auto *afd = dyn_cast<AbstractFunctionDecl>(member)) {
       // Add synthesized members to a side table and sort them by their mangled
       // name, since they could have been added to the class in any order.