AST: Minor generics changes

include/swift/AST/ASTContext.h

@@ -1343,8 +1343,8 @@ class ASTContext final {
   /// particular, the opened archetype signature does not have requirements for
   /// conformances inherited from superclass constraints while existential
   /// values do.
-  CanGenericSignature getOpenedArchetypeSignature(Type type,
-                                                  GenericSignature parentSig);
+  CanGenericSignature getOpenedExistentialSignature(Type type,
+                                                    GenericSignature parentSig);
 
   GenericSignature getOverrideGenericSignature(const ValueDecl *base,
                                                const ValueDecl *derived);

include/swift/AST/Type.h

@@ -282,13 +282,11 @@ class Type {
   /// Transform the given type by recursively applying the user-provided
   /// function to each node.
   ///
-  /// If the function returns \c None, the transform operation will
-  ///
   /// \param fn A function object which accepts a type pointer and returns a
   /// transformed type, a null type (which will propagate out the null type),
   /// or None (to indicate that the transform operation should recursively
   /// transform the children). The function object should use \c dyn_cast rather
-  /// than \c getAs when the transform is intended to preserve sugar
+  /// than \c getAs when the transform is intended to preserve sugar.
   ///
   /// \returns the result of transforming the type.
   Type transformRec(llvm::function_ref<Optional<Type>(TypeBase *)> fn) const;

lib/AST/ASTContext.cpp

@@ -4655,7 +4655,7 @@ GenericEnvironment *
 GenericEnvironment::forOpenedExistential(
     Type existential, GenericSignature parentSig, UUID uuid) {
   auto &ctx = existential->getASTContext();
-  auto signature = ctx.getOpenedArchetypeSignature(existential, parentSig);
+  auto signature = ctx.getOpenedExistentialSignature(existential, parentSig);
   return GenericEnvironment::forOpenedArchetypeSignature(existential, signature, uuid);
 }
 
@@ -5199,7 +5199,7 @@ Type OpenedArchetypeType::getSelfInterfaceTypeFromContext(GenericSignature paren
 }
 
 CanGenericSignature
-ASTContext::getOpenedArchetypeSignature(Type type, GenericSignature parentSig) {
+ASTContext::getOpenedExistentialSignature(Type type, GenericSignature parentSig) {
   assert(type->isExistentialType());
 
   if (auto existential = type->getAs<ExistentialType>())

lib/AST/ASTPrinter.cpp

@@ -1679,6 +1679,9 @@ void PrintAST::printSingleDepthOfGenericSignature(
     llvm::interleave(
         genericParams,
         [&](GenericTypeParamType *param) {
+          if (param->isTypeSequence())
+            Printer.printAttrName("@_typeSequence ");
+
           if (!subMap.empty()) {
             printType(substParam(param));
           } else if (auto *GP = param->getDecl()) {
@@ -3473,6 +3476,8 @@ void PrintAST::visitTypeAliasDecl(TypeAliasDecl *decl) {
 
 void PrintAST::visitGenericTypeParamDecl(GenericTypeParamDecl *decl) {
   recordDeclLoc(decl, [&] {
+    if (decl->isTypeSequence())
+      Printer.printAttrName("@_typeSequence ");
     Printer.printName(decl->getName(), PrintNameContext::GenericParameter);
   });
 

lib/AST/Decl.cpp

@@ -4168,7 +4168,7 @@ GenericParameterReferenceInfo ValueDecl::findExistentialSelfReferences(
   // Note: a non-null GenericSignature would violate the invariant that
   // the protocol 'Self' type referenced from the requirement's interface
   // type is the same as the existential 'Self' type.
-  auto sig = getASTContext().getOpenedArchetypeSignature(baseTy,
+  auto sig = getASTContext().getOpenedExistentialSignature(baseTy,
       GenericSignature());
 
   auto genericParam = sig.getGenericParams().front();

lib/AST/RequirementMachine/RequirementMachine.cpp

@@ -556,8 +556,11 @@ void RequirementMachine::dump(llvm::raw_ostream &out) const {
     out << " ]";
   } else {
     out << "fresh signature <";
-    for (auto paramTy : Params)
-      out << " " << Type(paramTy);
+    for (auto paramTy : Params) {
+      out << " " << paramTy;
+      if (paramTy->castTo<GenericTypeParamType>()->isTypeSequence())
+        out << "…";
+    }
     out << " >";
   }
   out << "\n";

lib/AST/RequirementMachine/Symbol.cpp

@@ -675,9 +675,15 @@ void Symbol::dump(llvm::raw_ostream &out) const {
     return;
   }
 
-  case Kind::GenericParam:
-    out << Type(getGenericParam());
+  case Kind::GenericParam: {
+    auto *gp = getGenericParam();
+    if (gp->isTypeSequence()) {
+      out << "(" << Type(gp) << "…)";
+    } else {
+      out << Type(gp);
+    }
     return;
+  }
 
   case Kind::Layout:
     out << "[layout: ";

lib/AST/Type.cpp

@@ -511,7 +511,7 @@ Type TypeBase::typeEraseOpenedArchetypesWithRoot(
   if (!hasOpenedExistential())
     return type;
 
-  const auto sig = root->getASTContext().getOpenedArchetypeSignature(
+  const auto sig = root->getASTContext().getOpenedExistentialSignature(
       root->getExistentialType(), useDC->getGenericSignatureOfContext());
 
   unsigned metatypeDepth = 0;
@@ -4163,7 +4163,7 @@ CanType ProtocolCompositionType::getMinimalCanonicalType(
   // Use generic signature minimization: the requirements of the signature will
   // represent the minimal composition.
   auto sig = useDC->getGenericSignatureOfContext();
-  const auto Sig = Ctx.getOpenedArchetypeSignature(CanTy, sig);
+  const auto Sig = Ctx.getOpenedExistentialSignature(CanTy, sig);
   const auto &Reqs = Sig.getRequirements();
   if (Reqs.size() == 1) {
     return Reqs.front().getSecondType()->getCanonicalType();

lib/IRGen/GenMeta.cpp

@@ -6168,7 +6168,7 @@ irgen::emitExtendedExistentialTypeShape(IRGenModule &IGM,
     }
 
     CanGenericSignature reqSig =
-      IGM.Context.getOpenedArchetypeSignature(existentialType, genSig);
+      IGM.Context.getOpenedExistentialSignature(existentialType, genSig);
 
     CanType typeExpression;
     if (metatypeDepth > 0) {

lib/SILOptimizer/Utils/Existential.cpp

@@ -249,15 +249,15 @@ void ConcreteExistentialInfo::initializeSubstitutionMap(
   // Construct a single-generic-parameter substitution map directly to the
   // ConcreteType with this existential's full list of conformances.
   //
-  // NOTE: getOpenedArchetypeSignature() generates the signature for passing an
+  // NOTE: getOpenedExistentialSignature() generates the signature for passing an
   // opened existential as a generic parameter. No opened archetypes are
   // actually involved here--the API is only used as a convenient way to create
   // a substitution map. Since opened archetypes have different conformances
   // than their corresponding existential, ExistentialConformances needs to be
   // filtered when using it with this (phony) generic signature.
   CanGenericSignature ExistentialSig =
-      M->getASTContext().getOpenedArchetypeSignature(ExistentialType,
-                                                     GenericSignature());
+      M->getASTContext().getOpenedExistentialSignature(ExistentialType,
+                                                       GenericSignature());
   ExistentialSubs = SubstitutionMap::get(
       ExistentialSig, [&](SubstitutableType *type) { return ConcreteType; },
       [&](CanType /*depType*/, Type /*replaceType*/,

lib/Sema/ConstraintSystem.cpp

@@ -1924,8 +1924,8 @@ typeEraseExistentialSelfReferences(
   }
 
   const auto existentialSig =
-      baseTy->getASTContext().getOpenedArchetypeSignature(baseTy,
-                                                          GenericSignature());
+      baseTy->getASTContext().getOpenedExistentialSignature(baseTy,
+                                                            GenericSignature());
 
   unsigned metatypeDepth = 0;
 
@@ -6561,7 +6561,7 @@ static bool doesMemberHaveUnfulfillableConstraintsWithExistentialBase(
 
       return Action::Stop;
     }
-  } isDependentOnSelfWalker(member->getASTContext().getOpenedArchetypeSignature(
+  } isDependentOnSelfWalker(member->getASTContext().getOpenedExistentialSignature(
       baseTy, GenericSignature()));
 
   for (const auto &req : sig.getRequirements()) {