[APINotes] Add support for SWIFT_RETURED_AS_UNRETAINED

Author: fahadnayyar

clang/include/clang/APINotes/Types.h

@@ -737,6 +737,7 @@ class TagInfo : public CommonTypeInfo {
   std::optional<std::string> SwiftImportAs;
   std::optional<std::string> SwiftRetainOp;
   std::optional<std::string> SwiftReleaseOp;
+  std::optional<std::string> SwiftDefaultOwnership;
 
   /// The Swift protocol that this type should be automatically conformed to.
   std::optional<std::string> SwiftConformance;
@@ -786,6 +787,8 @@ class TagInfo : public CommonTypeInfo {
       SwiftRetainOp = RHS.SwiftRetainOp;
     if (!SwiftReleaseOp)
       SwiftReleaseOp = RHS.SwiftReleaseOp;
+    if (!SwiftDefaultOwnership)
+      SwiftDefaultOwnership = RHS.SwiftDefaultOwnership;
 
     if (!SwiftConformance)
       SwiftConformance = RHS.SwiftConformance;
@@ -815,6 +818,7 @@ inline bool operator==(const TagInfo &LHS, const TagInfo &RHS) {
          LHS.SwiftImportAs == RHS.SwiftImportAs &&
          LHS.SwiftRetainOp == RHS.SwiftRetainOp &&
          LHS.SwiftReleaseOp == RHS.SwiftReleaseOp &&
+         LHS.SwiftDefaultOwnership == RHS.SwiftDefaultOwnership &&
          LHS.SwiftConformance == RHS.SwiftConformance &&
          LHS.isFlagEnum() == RHS.isFlagEnum() &&
          LHS.isSwiftCopyable() == RHS.isSwiftCopyable() &&

clang/lib/APINotes/APINotesReader.cpp

@@ -624,6 +624,13 @@ class TagTableInfo
                                         ReleaseOpLength - 1);
       Data += ReleaseOpLength - 1;
     }
+    unsigned DefaultOwnershipLength =
+        endian::readNext<uint16_t, llvm::endianness::little>(Data);
+    if (DefaultOwnershipLength > 0) {
+      Info.SwiftDefaultOwnership = std::string(
+          reinterpret_cast<const char *>(Data), DefaultOwnershipLength - 1);
+      Data += DefaultOwnershipLength - 1;
+    }
     if (unsigned ConformanceLength =
             endian::readNext<uint16_t, llvm::endianness::little>(Data)) {
       Info.SwiftConformance = std::string(reinterpret_cast<const char *>(Data),

clang/lib/APINotes/APINotesWriter.cpp

@@ -1274,6 +1274,7 @@ class TagTableInfo : public CommonTypeTableInfo<TagTableInfo, TagInfo> {
     return 2 + (TI.SwiftImportAs ? TI.SwiftImportAs->size() : 0) +
            2 + (TI.SwiftRetainOp ? TI.SwiftRetainOp->size() : 0) +
            2 + (TI.SwiftReleaseOp ? TI.SwiftReleaseOp->size() : 0) +
+           2 + (TI.SwiftDefaultOwnership ? TI.SwiftDefaultOwnership->size() : 0) +
            2 + (TI.SwiftConformance ? TI.SwiftConformance->size() : 0) +
            3 + getCommonTypeInfoSize(TI);
     // clang-format on
@@ -1322,6 +1323,12 @@ class TagTableInfo : public CommonTypeTableInfo<TagTableInfo, TagInfo> {
     } else {
       writer.write<uint16_t>(0);
     }
+    if (auto DefaultOwnership = TI.SwiftDefaultOwnership) {
+      writer.write<uint16_t>(DefaultOwnership->size() + 1);
+      OS.write(DefaultOwnership->c_str(), DefaultOwnership->size());
+    } else {
+      writer.write<uint16_t>(0);
+    }
     if (auto Conformance = TI.SwiftConformance) {
       writer.write<uint16_t>(Conformance->size() + 1);
       OS.write(Conformance->c_str(), Conformance->size());

clang/lib/APINotes/APINotesYAMLCompiler.cpp

@@ -460,6 +460,7 @@ struct Tag {
   std::optional<std::string> SwiftImportAs;
   std::optional<std::string> SwiftRetainOp;
   std::optional<std::string> SwiftReleaseOp;
+  std::optional<std::string> SwiftDefaultOwnership;
   std::optional<std::string> SwiftConformance;
   std::optional<EnumExtensibilityKind> EnumExtensibility;
   std::optional<bool> FlagEnum;
@@ -500,6 +501,7 @@ template <> struct MappingTraits<Tag> {
     IO.mapOptional("SwiftImportAs", T.SwiftImportAs);
     IO.mapOptional("SwiftReleaseOp", T.SwiftReleaseOp);
     IO.mapOptional("SwiftRetainOp", T.SwiftRetainOp);
+    IO.mapOptional("SwiftDefaultOwnership", T.SwiftDefaultOwnership);
     IO.mapOptional("SwiftConformsTo", T.SwiftConformance);
     IO.mapOptional("EnumExtensibility", T.EnumExtensibility);
     IO.mapOptional("FlagEnum", T.FlagEnum);
@@ -990,6 +992,8 @@ class YAMLConverter {
       TI.SwiftReleaseOp = T.SwiftReleaseOp;
     if (T.SwiftConformance)
       TI.SwiftConformance = T.SwiftConformance;
+    if (T.SwiftDefaultOwnership)
+      TI.SwiftDefaultOwnership = T.SwiftDefaultOwnership;
 
     if (T.SwiftCopyable)
       TI.setSwiftCopyable(T.SwiftCopyable);

clang/lib/Sema/SemaAPINotes.cpp

@@ -643,6 +643,9 @@ static void ProcessAPINotes(Sema &S, TagDecl *D, const api_notes::TagInfo &Info,
   if (auto ReleaseOp = Info.SwiftReleaseOp)
     D->addAttr(
         SwiftAttrAttr::Create(S.Context, "release:" + ReleaseOp.value()));
+  if (auto DefaultOwnership = Info.SwiftDefaultOwnership)
+    D->addAttr(SwiftAttrAttr::Create(
+        S.Context, "returned_as_" + DefaultOwnership.value() + "_by_default"));
 
   if (auto ConformsTo = Info.SwiftConformance)
     D->addAttr(

clang/test/APINotes/Inputs/Headers/SwiftImportAs.apinotes

@@ -14,6 +14,11 @@ Tags:
   SwiftReleaseOp: RCRelease
   SwiftRetainOp: RCRetain
   SwiftConformsTo: MySwiftModule.MySwiftRefCountedProtocol
+- Name: RefCountedTypeWithDefaultConvention
+  SwiftImportAs: reference
+  SwiftReleaseOp: release
+  SwiftRetainOp: retain
+  SwiftDefaultOwnership: unretained
 - Name: NonCopyableType
   SwiftCopyable: false
   SwiftConformsTo: MySwiftModule.MySwiftNonCopyableProtocol

clang/test/APINotes/Inputs/Headers/SwiftImportAs.h

@@ -19,3 +19,7 @@ struct CopyableType { int value; };
 
 struct NonEscapableType { int value; };
 struct EscapableType { int value; };
+
+struct RefCountedTypeWithDefaultConvention {};
+inline void retain(RefCountedType *x) {}
+inline void release(RefCountedType *x) {}

clang/test/APINotes/swift-import-as.cpp

@@ -2,6 +2,7 @@
 // RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -fsyntax-only -I %S/Inputs/Headers %s -x c++
 // RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -I %S/Inputs/Headers %s -x c++ -ast-dump -ast-dump-filter ImmortalRefType | FileCheck -check-prefix=CHECK-IMMORTAL %s
 // RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -I %S/Inputs/Headers %s -x c++ -ast-dump -ast-dump-filter RefCountedType | FileCheck -check-prefix=CHECK-REF-COUNTED %s
+// RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -I %S/Inputs/Headers %s -x c++ -ast-dump -ast-dump-filter RefCountedTypeWithDefaultConvention | FileCheck -check-prefix=CHECK-REF-COUNTED-DEFAULT %s
 // RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -I %S/Inputs/Headers %s -x c++ -ast-dump -ast-dump-filter NonCopyableType | FileCheck -check-prefix=CHECK-NON-COPYABLE %s
 // RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -I %S/Inputs/Headers %s -x c++ -ast-dump -ast-dump-filter CopyableType | FileCheck -check-prefix=CHECK-COPYABLE %s
 // RUN: %clang_cc1 -fmodules -fblocks -fimplicit-module-maps -fmodules-cache-path=%t/ModulesCache -fdisable-module-hash -fapinotes-modules -I %S/Inputs/Headers %s -x c++ -ast-dump -ast-dump-filter NonEscapableType | FileCheck -check-prefix=CHECK-NON-ESCAPABLE %s
@@ -26,6 +27,13 @@
 // CHECK-REF-COUNTED: SwiftAttrAttr {{.+}} <<invalid sloc>> "release:RCRelease"
 // CHECK-REF-COUNTED: SwiftAttrAttr {{.+}} <<invalid sloc>> "conforms_to:MySwiftModule.MySwiftRefCountedProtocol"
 
+// CHECK-REF-COUNTED-DEFAULT: Dumping RefCountedTypeWithDefaultConvention:
+// CHECK-REF-COUNTED-DEFAULT-NEXT: CXXRecordDecl {{.+}} imported in SwiftImportAs {{.+}} struct RefCountedTypeWithDefaultConvention
+// CHECK-REF-COUNTED-DEFAULT: SwiftAttrAttr {{.+}} <<invalid sloc>> "import_reference"
+// CHECK-REF-COUNTED-DEFAULT: SwiftAttrAttr {{.+}} <<invalid sloc>> "retain:retain"
+// CHECK-REF-COUNTED-DEFAULT: SwiftAttrAttr {{.+}} <<invalid sloc>> "release:release"
+// CHECK-REF-COUNTED-DEFAULT: SwiftAttrAttr {{.+}} <<invalid sloc>> "returned_as_unretained_by_default"
+
 // CHECK-NON-COPYABLE: Dumping NonCopyableType:
 // CHECK-NON-COPYABLE-NEXT: CXXRecordDecl {{.+}} imported in SwiftImportAs {{.+}} struct NonCopyableType
 // CHECK-NON-COPYABLE: SwiftAttrAttr {{.+}} <<invalid sloc>> "conforms_to:MySwiftModule.MySwiftNonCopyableProtocol"