Don't print conformance attributes redundantly in -preserve-types-as-written.

Since we no longer remove these attributes from the AttributedTypeRepr,
if we print based on the TypeRepr, we'll print them twice.  The best
solution is to only print the attributes based on the inheritance clause
if we're not printing the type based on the TypeRepr.

Fixes rdar://122965951.

Author: rjmccall

lib/AST/ASTPrinter.cpp

@@ -887,8 +887,10 @@ class PrintAST : public ASTVisitor<PrintAST> {
     printTransformedTypeWithOptions(T, Options);
   }
 
-  void printTypeLocWithOptions(const TypeLoc &TL, const PrintOptions &options) {
+  void printTypeLocWithOptions(const TypeLoc &TL, const PrintOptions &options,
+      std::optional<llvm::function_ref<void()>> printBeforeType = std::nullopt) {
     if (CurrentType && TL.getType()) {
+      if (printBeforeType) (*printBeforeType)();
       printTransformedTypeWithOptions(TL.getType(), options);
       return;
     }
@@ -901,11 +903,21 @@ class PrintAST : public ASTVisitor<PrintAST> {
       return;
     }
 
+    if (printBeforeType) (*printBeforeType)();
     TL.getType().print(Printer, options);
   }
 
   void printTypeLoc(const TypeLoc &TL) { printTypeLocWithOptions(TL, Options); }
 
+  /// Print a TypeLoc.  If we decide to print based on the type, rather than
+  /// based on the TypeRepr, call the given function before printing the type;
+  /// this is useful if there are attributes in the TypeRepr which don't end
+  /// up being part of the type, such as `@unchecked` in inheritance clauses.
+  void printTypeLoc(const TypeLoc &TL,
+                    llvm::function_ref<void()> printBeforeType) {
+    printTypeLocWithOptions(TL, Options, printBeforeType);
+  }
+
   void printTypeLocForImplicitlyUnwrappedOptional(TypeLoc TL, bool IUO) {
     PrintOptions options = Options;
     options.PrintOptionalAsImplicitlyUnwrapped = IUO;
@@ -2710,15 +2722,15 @@ void PrintAST::printInherited(const Decl *decl) {
   Printer << ": ";
 
   interleave(TypesToPrint, [&](InheritedEntry inherited) {
-    if (inherited.isUnchecked())
-      Printer << "@unchecked ";
-    if (inherited.isRetroactive() &&
-        !llvm::is_contained(Options.ExcludeAttrList, TypeAttrKind::Retroactive))
-      Printer << "@retroactive ";
-    if (inherited.isPreconcurrency())
-      Printer << "@preconcurrency ";
-
-    printTypeLoc(inherited);
+    printTypeLoc(inherited, [&] {
+      if (inherited.isUnchecked())
+        Printer << "@unchecked ";
+      if (inherited.isRetroactive() &&
+          !llvm::is_contained(Options.ExcludeAttrList, TypeAttrKind::Retroactive))
+        Printer << "@retroactive ";
+      if (inherited.isPreconcurrency())
+        Printer << "@preconcurrency ";
+    });
   }, [&]() {
     Printer << ", ";
   });

test/ModuleInterface/concurrency.swift

@@ -43,6 +43,10 @@ public struct InferredPreconcurrencyMainActor: PreconcurrencyMainProtocol {
   public func requirement() {}
 }
 
+// rdar://122965951
+public struct UncheckedSendable: @unchecked Sendable {}
+extension UnsafePointer : @retroactive @unchecked Sendable {}
+
 // RUN: %target-typecheck-verify-swift -enable-experimental-concurrency -I %t
 
 #else
@@ -54,7 +58,7 @@ func callFn() async {
 }
 #endif
 
-// RUN: %FileCheck %s < %t/Library.swiftinterface
+// RUN: %FileCheck --check-prefix=CHECK --check-prefix=CHECK-TYPECHECKED %s < %t/Library.swiftinterface
 // CHECK: // swift-module-flags:{{.*}} -enable-experimental-concurrency
 // CHECK: public func fn() async
 // CHECK: public func reasyncFn(_: () async -> ()) reasync
@@ -77,7 +81,12 @@ func callFn() async {
 // CHECK-NEXT:   @_Concurrency.MainActor @preconcurrency public func requirement()
 // CHECK-NEXT: }
 
+// CHECK-TYPECHECKED: public struct UncheckedSendable : @unchecked Swift.Sendable
+// CHECK-ASWRITTEN: public struct UncheckedSendable : @unchecked Sendable
+
+// CHECK-TYPECHECKED: extension Swift.UnsafePointer : @unchecked @retroactive Swift.Sendable
+// CHECK-ASWRITTEN: extension UnsafePointer : @retroactive @unchecked Sendable
 
 // RUN: %target-swift-emit-module-interface(%t/LibraryPreserveTypesAsWritten.swiftinterface) %s -enable-experimental-concurrency -DLIBRARY -module-name LibraryPreserveTypesAsWritten -module-interface-preserve-types-as-written
 // RUN: %target-swift-typecheck-module-from-interface(%t/LibraryPreserveTypesAsWritten.swiftinterface) -enable-experimental-concurrency
-// RUN: %FileCheck %s < %t/LibraryPreserveTypesAsWritten.swiftinterface
+// RUN: %FileCheck --check-prefix=CHECK --check-prefix=CHECK-ASWRITTEN %s < %t/LibraryPreserveTypesAsWritten.swiftinterface