[clang][ExtractAPI] Add support for Objective-C categories

Differential Revision: https://reviews.llvm.org/D152770

1 files changed, 65 insertions, 13 deletions

diff --git a/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp b/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
index c9fbf0d..7783035 100644
--- a/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
+++ b/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
@@ -328,7 +328,13 @@ serializeDeclarationFragments(const DeclarationFragments &DF) {
 ///     Objective-C methods). Can be used as sub-headings for documentation.
 Object serializeNames(const APIRecord &Record) {
   Object Names;
-  Names["title"] = Record.Name;
+  if (auto *CategoryRecord =
+          dyn_cast_or_null<const ObjCCategoryRecord>(&Record))
+    Names["title"] =
+        (CategoryRecord->Interface.Name + " (" + Record.Name + ")").str();
+  else
+    Names["title"] = Record.Name;
+
   serializeArray(Names, "subHeading",
                  serializeDeclarationFragments(Record.SubHeading));
   DeclarationFragments NavigatorFragments;
@@ -432,9 +438,12 @@ Object serializeSymbolKind(APIRecord::RecordKind RK, Language Lang) {
     Kind["displayName"] = "Class";
     break;
   case APIRecord::RK_ObjCCategory:
-    // We don't serialize out standalone Objective-C category symbols yet.
-    llvm_unreachable("Serializing standalone Objective-C category symbols is "
-                     "not supported.");
+    Kind["identifier"] = AddLangPrefix("class.extension");
+    Kind["displayName"] = "Class Extension";
+    break;
+  case APIRecord::RK_ObjCCategoryModule:
+    Kind["identifier"] = AddLangPrefix("module.extension");
+    Kind["displayName"] = "Module Extension";
     break;
   case APIRecord::RK_ObjCProtocol:
     Kind["identifier"] = AddLangPrefix("protocol");
@@ -563,14 +572,16 @@ bool generatePathComponents(
     if (!ParentRecord)
       ParentRecord = API.findRecordForUSR(CurrentParent->ParentUSR);
 
-    // If the parent is a category then we need to pretend this belongs to the
-    // associated interface.
+    // If the parent is a category extended from internal module then we need to
+    // pretend this belongs to the associated interface.
     if (auto *CategoryRecord =
             dyn_cast_or_null<ObjCCategoryRecord>(ParentRecord)) {
-      ParentRecord = API.findRecordForUSR(CategoryRecord->Interface.USR);
-      CurrentParentComponent = PathComponent(CategoryRecord->Interface.USR,
-                                             CategoryRecord->Interface.Name,
-                                             APIRecord::RK_ObjCInterface);
+      if (!CategoryRecord->IsFromExternalModule) {
+        ParentRecord = API.findRecordForUSR(CategoryRecord->Interface.USR);
+        CurrentParentComponent = PathComponent(CategoryRecord->Interface.USR,
+                                               CategoryRecord->Interface.Name,
+                                               APIRecord::RK_ObjCInterface);
+      }
     }
 
     // The parent record doesn't exist which means the symbol shouldn't be
@@ -709,6 +720,8 @@ StringRef SymbolGraphSerializer::getRelationshipString(RelationshipKind Kind) {
     return "inheritsFrom";
   case RelationshipKind::ConformsTo:
     return "conformsTo";
+  case RelationshipKind::ExtensionTo:
+    return "extensionTo";
   }
   llvm_unreachable("Unhandled relationship kind");
 }
@@ -820,6 +833,45 @@ void SymbolGraphSerializer::visitObjCContainerRecord(
   }
 }
 
+void SymbolGraphSerializer::visitObjCCategoryRecord(
+    const ObjCCategoryRecord &Record) {
+  if (!Record.IsFromExternalModule)
+    return;
+
+  // Check if the current Category' parent has been visited before, if so skip.
+  if (!(visitedCategories.contains(Record.Interface.Name) > 0)) {
+    visitedCategories.insert(Record.Interface.Name);
+    Object Obj;
+    serializeObject(Obj, "identifier",
+                    serializeIdentifier(Record, API.getLanguage()));
+    serializeObject(Obj, "kind",
+                    serializeSymbolKind(APIRecord::RK_ObjCCategoryModule,
+                                        API.getLanguage()));
+    Obj["accessLevel"] = "public";
+    Symbols.emplace_back(std::move(Obj));
+  }
+
+  Object Relationship;
+  Relationship["source"] = Record.USR;
+  Relationship["target"] = Record.Interface.USR;
+  Relationship["targetFallback"] = Record.Interface.Name;
+  Relationship["kind"] = getRelationshipString(RelationshipKind::ExtensionTo);
+  Relationships.emplace_back(std::move(Relationship));
+
+  auto ObjCCategory = serializeAPIRecord(Record);
+
+  if (!ObjCCategory)
+    return;
+
+  Symbols.emplace_back(std::move(*ObjCCategory));
+  serializeMembers(Record, Record.Methods);
+  serializeMembers(Record, Record.Properties);
+
+  // Surface the protocols of the category to the interface.
+  for (const auto &Protocol : Record.Protocols)
+    serializeRelationship(RelationshipKind::ConformsTo, Record, Protocol);
+}
+
 void SymbolGraphSerializer::visitMacroDefinitionRecord(
     const MacroDefinitionRecord &Record) {
   auto Macro = serializeAPIRecord(Record);
@@ -858,6 +910,9 @@ void SymbolGraphSerializer::serializeSingleRecord(const APIRecord *Record) {
   case APIRecord::RK_ObjCProtocol:
     visitObjCContainerRecord(*cast<ObjCProtocolRecord>(Record));
     break;
+  case APIRecord::RK_ObjCCategory:
+    visitObjCCategoryRecord(*cast<ObjCCategoryRecord>(Record));
+    break;
   case APIRecord::RK_MacroDefinition:
     visitMacroDefinitionRecord(*cast<MacroDefinitionRecord>(Record));
     break;
@@ -926,9 +981,6 @@ SymbolGraphSerializer::serializeSingleSymbolSGF(StringRef USR,
   if (!Record)
     return {};
 
-  if (isa<ObjCCategoryRecord>(Record))
-    return {};
-
   Object Root;
   APIIgnoresList EmptyIgnores;
   SymbolGraphSerializer Serializer(API, EmptyIgnores,