[ASTPrinter] Simplify archetype printing by visiting the interface type.

lib/AST/ASTPrinter.cpp

@@ -6289,8 +6289,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
 
   void visitOpenedArchetypeType(OpenedArchetypeType *T) {
     if (auto parent = T->getParent()) {
-      visitParentType(parent);
-      printArchetypeCommon(T, getAbstractTypeParamDecl(T));
+      printArchetypeCommon(T);
       return;
     }
 
@@ -6299,8 +6298,20 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
     visit(T->getExistentialType());
   }
 
-  void printArchetypeCommon(ArchetypeType *T,
-                            const AbstractTypeParamDecl *Decl) {
+  void printDependentMember(DependentMemberType *T) {
+    if (auto *const Assoc = T->getAssocType()) {
+      if (Options.ProtocolQualifiedDependentMemberTypes) {
+        Printer << "[";
+        Printer.printName(Assoc->getProtocol()->getName());
+        Printer << "]";
+      }
+      Printer.printTypeRef(T, Assoc, T->getName());
+    } else {
+      Printer.printName(T->getName());
+    }
+  }
+
+  void printArchetypeCommon(ArchetypeType *T) {
     if (Options.AlternativeTypeNames) {
       auto found = Options.AlternativeTypeNames->find(T->getCanonicalType());
       if (found != Options.AlternativeTypeNames->end()) {
@@ -6309,36 +6320,22 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
       }
     }
 
-    const auto Name = T->getName();
-    if (Name.empty()) {
-      Printer << "<anonymous>";
-    } else if (Decl) {
-      Printer.printTypeRef(T, Decl, Name);
+    auto interfaceType = T->getInterfaceType();
+    if (auto *dependentMember = interfaceType->getAs<DependentMemberType>()) {
+      visitParentType(T->getParent());
+      printDependentMember(dependentMember);
     } else {
-      Printer.printName(Name);
+      visit(interfaceType);
     }
   }
 
-  static AbstractTypeParamDecl *getAbstractTypeParamDecl(ArchetypeType *T) {
-    if (auto gp = T->getInterfaceType()->getAs<GenericTypeParamType>()) {
-      return gp->getDecl();
-    }
-
-    auto depMemTy = T->getInterfaceType()->castTo<DependentMemberType>();
-    return depMemTy->getAssocType();
-  }
-
   void visitPrimaryArchetypeType(PrimaryArchetypeType *T) {
-    if (auto parent = T->getParent())
-      visitParentType(parent);
-
-    printArchetypeCommon(T, getAbstractTypeParamDecl(T));
+    printArchetypeCommon(T);
   }
 
   void visitOpaqueTypeArchetypeType(OpaqueTypeArchetypeType *T) {
     if (auto parent = T->getParent()) {
-      visitParentType(parent);
-      printArchetypeCommon(T, getAbstractTypeParamDecl(T));
+      printArchetypeCommon(T);
       return;
     }
 
@@ -6415,9 +6412,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
   }
 
   void visitSequenceArchetypeType(SequenceArchetypeType *T) {
-    if (auto parent = T->getParent())
-      visitParentType(parent);
-    printArchetypeCommon(T, getAbstractTypeParamDecl(T));
+    printArchetypeCommon(T);
   }
 
   void visitGenericTypeParamType(GenericTypeParamType *T) {
@@ -6475,16 +6470,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
 
   void visitDependentMemberType(DependentMemberType *T) {
     visitParentType(T->getBase());
-    if (auto *const Assoc = T->getAssocType()) {
-      if (Options.ProtocolQualifiedDependentMemberTypes) {
-        Printer << "[";
-        Printer.printName(Assoc->getProtocol()->getName());
-        Printer << "]";
-      }
-      Printer.printTypeRef(T, Assoc, T->getName());
-    } else {
-      Printer.printName(T->getName());
-    }
+    printDependentMember(T);
   }
 
 #define REF_STORAGE(Name, name, ...) \

lib/AST/Type.cpp

@@ -6242,6 +6242,12 @@ bool TypeBase::hasSimpleTypeRepr() const {
   case TypeKind::OpenedArchetype:
     return false;
 
+  case TypeKind::PrimaryArchetype: {
+    auto archetype = cast<const PrimaryArchetypeType>(this);
+    auto interface = archetype->getInterfaceType();
+    return interface->hasSimpleTypeRepr();
+  }
+
   case TypeKind::ProtocolComposition: {
     // 'Any', 'AnyObject' and single protocol compositions are simple
     auto composition = cast<const ProtocolCompositionType>(this);

test/Generics/opaque_archetype_concrete_requirement.swift

@@ -30,7 +30,7 @@ struct DefinesOpaqueP1 : P {
 struct ConcreteHasP<T : P1, TT : P2, TU> {}
 
 // CHECK-LABEL: ExtensionDecl line={{.*}} base=ConcreteHasP
-// CHECK-NEXT: Generic signature: <T, TT, TU where T == some P1, TT == (some P1).T, TU == (some P1).U>
+// CHECK-NEXT: Generic signature: <T, TT, TU where T == some P1, TT == (some P1).[P1]T, TU == (some P1).[P1]U>
 extension ConcreteHasP where T == DefinesOpaqueP1.T, TT == T.T, TU == T.U {
   func checkSameType1(_ t: TT) -> DefinesOpaqueP1.T.T { return t }
   func checkSameType2(_ u: TU) -> DefinesOpaqueP1.T.U { return u }
@@ -47,7 +47,7 @@ protocol HasP {
 }
 
 // CHECK-LABEL: ExtensionDecl line={{.*}} base=HasP
-// CHECK-NEXT: Generic signature: <Self where Self : HasP, Self.[HasP]T == some P1, Self.[HasP]U == G<(some P1).T>>
+// CHECK-NEXT: Generic signature: <Self where Self : HasP, Self.[HasP]T == some P1, Self.[HasP]U == G<(some P1).[P1]T>>
 extension HasP where T == DefinesOpaqueP1.T, U == G<T.T> {
   func checkSameType1(_ t: T.T) -> DefinesOpaqueP1.T.T { return t }
   func checkSameType2(_ u: T.U) -> DefinesOpaqueP1.T.U { return u }

test/type/opaque_parameters.swift

@@ -6,6 +6,7 @@ protocol Q {
   associatedtype A: P & Equatable
 
   func f() -> A
+  func takesA(_: A)
 }
 
 extension Int: P { }
@@ -16,17 +17,24 @@ extension Array: Q where Element: P, Element: Equatable {
   func f() -> Element {
     return first!
   }
+
+  func takesA(_: Element) {}
 }
 
 extension Set: Q where Element: P, Element: Equatable { // expected-warning {{redundant conformance constraint 'Element' : 'Equatable'}}
   func f() -> Element {
     return first!
   }
+
+  func takesA(_: Element) {}
 }
 
 // expected-note@+2{{where 'some Q' = 'Int'}}
 // expected-note@+1{{in call to function 'takesQ'}}
 func takesQ(_ q: some Q) -> Bool {
+  // expected-error@+1 {{cannot convert value of type 'Int' to expected argument type '(some Q).A'}}
+  q.takesA(1)
+
   return q.f() == q.f()
 }