[APINotes] Support SwiftImportAs for C++ structs

This upstreams a few Clang API Notes attributes that were recently added
downstream in the Apple fork
(swiftlang#7386).

Author: egorzhdan

clang/include/clang/APINotes/Types.h

@@ -660,6 +660,10 @@ class TagInfo : public CommonTypeInfo {
   unsigned IsFlagEnum : 1;
 
 public:
+  std::optional<std::string> SwiftImportAs;
+  std::optional<std::string> SwiftRetainOp;
+  std::optional<std::string> SwiftReleaseOp;
+
   std::optional<EnumExtensibilityKind> EnumExtensibility;
 
   TagInfo() : HasFlagEnum(0), IsFlagEnum(0) {}
@@ -677,6 +681,13 @@ class TagInfo : public CommonTypeInfo {
   TagInfo &operator|=(const TagInfo &RHS) {
     static_cast<CommonTypeInfo &>(*this) |= RHS;
 
+    if (!SwiftImportAs)
+      SwiftImportAs = RHS.SwiftImportAs;
+    if (!SwiftRetainOp)
+      SwiftRetainOp = RHS.SwiftRetainOp;
+    if (!SwiftReleaseOp)
+      SwiftReleaseOp = RHS.SwiftReleaseOp;
+
     if (!HasFlagEnum)
       setFlagEnum(RHS.isFlagEnum());
 
@@ -693,6 +704,9 @@ class TagInfo : public CommonTypeInfo {
 
 inline bool operator==(const TagInfo &LHS, const TagInfo &RHS) {
   return static_cast<const CommonTypeInfo &>(LHS) == RHS &&
+         LHS.SwiftImportAs == RHS.SwiftImportAs &&
+         LHS.SwiftRetainOp == RHS.SwiftRetainOp &&
+         LHS.SwiftReleaseOp == RHS.SwiftReleaseOp &&
          LHS.isFlagEnum() == RHS.isFlagEnum() &&
          LHS.EnumExtensibility == RHS.EnumExtensibility;
 }

clang/lib/APINotes/APINotesFormat.h

@@ -24,7 +24,7 @@ const uint16_t VERSION_MAJOR = 0;
 /// API notes file minor version number.
 ///
 /// When the format changes IN ANY WAY, this number should be incremented.
-const uint16_t VERSION_MINOR = 24; // EnumExtensibility + FlagEnum
+const uint16_t VERSION_MINOR = 25; // SwiftImportAs
 
 using IdentifierID = llvm::PointerEmbeddedInt<unsigned, 31>;
 using IdentifierIDField = llvm::BCVBR<16>;

clang/lib/APINotes/APINotesWriter.cpp

@@ -1124,7 +1124,10 @@ class CommonTypeTableInfo
 class TagTableInfo : public CommonTypeTableInfo<TagTableInfo, TagInfo> {
 public:
   unsigned getUnversionedInfoSize(const TagInfo &TI) {
-    return 1 + getCommonTypeInfoSize(TI);
+    return 2 + (TI.SwiftImportAs ? TI.SwiftImportAs->size() : 0) +
+           2 + (TI.SwiftRetainOp ? TI.SwiftRetainOp->size() : 0) +
+           2 + (TI.SwiftReleaseOp ? TI.SwiftReleaseOp->size() : 0) +
+           1 + getCommonTypeInfoSize(TI);
   }
 
   void emitUnversionedInfo(raw_ostream &OS, const TagInfo &TI) {
@@ -1142,6 +1145,25 @@ class TagTableInfo : public CommonTypeTableInfo<TagTableInfo, TagInfo> {
 
     writer.write<uint8_t>(Flags);
 
+    if (auto ImportAs = TI.SwiftImportAs) {
+      writer.write<uint16_t>(ImportAs->size() + 1);
+      OS.write(ImportAs->c_str(), ImportAs->size());
+    } else {
+      writer.write<uint16_t>(0);
+    }
+    if (auto RetainOp = TI.SwiftRetainOp) {
+      writer.write<uint16_t>(RetainOp->size() + 1);
+      OS.write(RetainOp->c_str(), RetainOp->size());
+    } else {
+      writer.write<uint16_t>(0);
+    }
+    if (auto ReleaseOp = TI.SwiftReleaseOp) {
+      writer.write<uint16_t>(ReleaseOp->size() + 1);
+      OS.write(ReleaseOp->c_str(), ReleaseOp->size());
+    } else {
+      writer.write<uint16_t>(0);
+    }
+
     emitCommonTypeInfo(OS, TI);
   }
 };

clang/lib/APINotes/APINotesYAMLCompiler.cpp

@@ -410,6 +410,9 @@ struct Tag {
   std::optional<bool> SwiftPrivate;
   std::optional<StringRef> SwiftBridge;
   std::optional<StringRef> NSErrorDomain;
+  std::optional<std::string> SwiftImportAs;
+  std::optional<std::string> SwiftRetainOp;
+  std::optional<std::string> SwiftReleaseOp;
   std::optional<EnumExtensibilityKind> EnumExtensibility;
   std::optional<bool> FlagEnum;
   std::optional<EnumConvenienceAliasKind> EnumConvenienceKind;
@@ -440,6 +443,9 @@ template <> struct MappingTraits<Tag> {
     IO.mapOptional("SwiftName", T.SwiftName, StringRef(""));
     IO.mapOptional("SwiftBridge", T.SwiftBridge);
     IO.mapOptional("NSErrorDomain", T.NSErrorDomain);
+    IO.mapOptional("SwiftImportAs", T.SwiftImportAs);
+    IO.mapOptional("SwiftReleaseOp", T.SwiftReleaseOp);
+    IO.mapOptional("SwiftRetainOp", T.SwiftRetainOp);
     IO.mapOptional("EnumExtensibility", T.EnumExtensibility);
     IO.mapOptional("FlagEnum", T.FlagEnum);
     IO.mapOptional("EnumKind", T.EnumConvenienceKind);