Print Sendable conformances for clang types

include/swift/AST/PrintOptions.h

@@ -235,6 +235,10 @@ struct PrintOptions {
   /// Whether to print unavailable parts of the AST.
   bool SkipUnavailable = false;
 
+  /// Whether to print synthesized extensions created by '@_nonSendable', even
+  /// if SkipImplicit or SkipUnavailable is set.
+  bool AlwaysPrintNonSendableExtensions = true;
+
   bool SkipSwiftPrivateClangDecls = false;
 
   /// Whether to skip internal stdlib declarations.
@@ -667,6 +671,7 @@ struct PrintOptions {
     PO.ShouldQualifyNestedDeclarations = QualifyNestedDeclarations::TypesOnly;
     PO.PrintParameterSpecifiers = true;
     PO.SkipImplicit = true;
+    PO.AlwaysPrintNonSendableExtensions = false;
     PO.AlwaysTryPrintParameterLabels = true;
     return PO;
   }

lib/AST/ASTPrinter.cpp

@@ -1769,6 +1769,24 @@ bool ShouldPrintChecker::shouldPrint(const Pattern *P,
   return ShouldPrint;
 }
 
+bool isNonSendableExtension(const Decl *D) {
+  ASTContext &ctx = D->getASTContext();
+
+  const ExtensionDecl *ED = dyn_cast<ExtensionDecl>(D);
+  if (!ED || !ED->getAttrs().isUnavailable(ctx))
+    return false;
+
+  auto nonSendable =
+      ED->getExtendedNominal()->getAttrs().getEffectiveSendableAttr();
+  if (!isa_and_nonnull<NonSendableAttr>(nonSendable))
+    return false;
+
+  // GetImplicitSendableRequest::evaluate() creates its extension with the
+  // attribute's AtLoc, so this is a good way to quickly check if the extension
+  // was synthesized for an '@_nonSendable' attribute.
+  return ED->getLocFromSource() == nonSendable->AtLoc;
+}
+
 bool ShouldPrintChecker::shouldPrint(const Decl *D,
                                      const PrintOptions &Options) {
   #if SWIFT_BUILD_ONLY_SYNTAXPARSERLIB
@@ -1791,15 +1809,18 @@ bool ShouldPrintChecker::shouldPrint(const Decl *D,
     return false;
   }
 
-  if (Options.SkipImplicit && D->isImplicit()) {
-    const auto &IgnoreList = Options.TreatAsExplicitDeclList;
-    if (std::find(IgnoreList.begin(), IgnoreList.end(), D) == IgnoreList.end())
+  // Optionally skip these checks for extensions synthesized for '@_nonSendable'
+  if (!Options.AlwaysPrintNonSendableExtensions || !isNonSendableExtension(D)) {
+    if (Options.SkipImplicit && D->isImplicit()) {
+      const auto &IgnoreList = Options.TreatAsExplicitDeclList;
+      if (!llvm::is_contained(IgnoreList, D))
         return false;
-  }
+    }
 
-  if (Options.SkipUnavailable &&
-      D->getAttrs().isUnavailable(D->getASTContext()))
-    return false;
+    if (Options.SkipUnavailable &&
+        D->getAttrs().isUnavailable(D->getASTContext()))
+      return false;
+  }
 
   if (Options.ExplodeEnumCaseDecls) {
     if (isa<EnumElementDecl>(D))

lib/AST/Module.cpp

@@ -909,6 +909,28 @@ SourceFile::getExternalRawLocsForDecl(const Decl *D) const {
 void ModuleDecl::getDisplayDecls(SmallVectorImpl<Decl*> &Results) const {
   // FIXME: Should this do extra access control filtering?
   FORWARD(getDisplayDecls, (Results));
+
+  // Force Sendable on all types, which might synthesize some extensions.
+  // FIXME: We can remove this if @_nonSendable stops creating extensions.
+  for (auto result : Results) {
+    if (auto NTD = dyn_cast<NominalTypeDecl>(result))
+      (void)swift::isSendableType(const_cast<ModuleDecl *>(this),
+                                  NTD->getDeclaredInterfaceType());
+  }
+
+  // Re-add anything from synthesized file units...
+  auto oldCutoff = Results.size();
+  for (auto file : getFiles())
+    if (auto synthFile = dyn_cast<SynthesizedFileUnit>(file))
+      synthFile->getDisplayDecls(Results);
+
+  // And then remove anything that was already in the results.
+  auto oldResults = makeArrayRef(Results).take_front(oldCutoff);
+  auto uniqueEnd = std::remove_if(Results.begin() + oldCutoff, Results.end(),
+                                   [&](auto result) {
+    return llvm::is_contained(oldResults, result);
+  });
+  Results.erase(uniqueEnd, Results.end());
 }
 
 ProtocolConformanceRef

lib/Sema/TypeCheckConcurrency.cpp

@@ -4004,6 +4004,8 @@ NormalProtocolConformance *GetImplicitSendableRequest::evaluate(
       auto inherits = ctx.AllocateCopy(makeArrayRef(
           InheritedEntry(TypeLoc::withoutLoc(proto->getDeclaredInterfaceType()),
                          /*isUnchecked*/true)));
+      // If you change the use of AtLoc in the ExtensionDecl, make sure you
+      // update isNonSendableExtension() in ASTPrinter.
       auto extension = ExtensionDecl::create(ctx, attrMakingUnavailable->AtLoc,
                                              nullptr, inherits,
                                              nominal->getModuleScopeContext(),

test/IDE/print_objc_concurrency_interface.swift

@@ -23,10 +23,17 @@ import _Concurrency
 // CHECK-SAME: @unchecked Sendable
 
 // CHECK-LABEL: class NonSendableClass
+// CHECK: @available(*, unavailable)
+// CHECK-NEXT: extension NonSendableClass : @unchecked Sendable {
 
 // CHECK-LABEL: class AuditedSendable :
 // CHECK-SAME: @unchecked Sendable
 
 // CHECK-LABEL: class AuditedNonSendable
+// CHECK: @available(*, unavailable)
+// CHECK-NEXT: extension AuditedNonSendable : @unchecked Sendable {
 
 // CHECK-LABEL: class AuditedBoth
+// CHECK: @available(*, unavailable)
+// CHECK-NEXT: extension AuditedBoth : @unchecked Sendable {
+

test/Serialization/Recovery/private-conformances.swift

@@ -10,7 +10,7 @@
 // RUN: %target-swift-frontend -emit-module -DPROTOCOL_LIB -DAFTER %s -module-name protocol_lib -emit-module-path %t/protocol_lib.swiftmodule
 
 // The conforming library's types should still deserialize.
-// RUN: %target-swift-ide-test -print-module -source-filename %s -module-to-print conforms_lib -I %t | %FileCheck %s
+// RUN: %target-swift-ide-test -print-module -source-filename %s -module-to-print conforms_lib -I %t -allow-compiler-errors | %FileCheck %s
 
 // Protocols that use a missing protocol have to disappear (see the FileCheck
 // lines).