[clang][extract-api] Add Objective-C Category support

Add (partial) support for Objective-C category records in ExtractAPI.
The current ExtractAPI collects everything for an Objective-C category,
but not fully serialized in the SymbolGraphSerializer. Categories
extending external interfaces are disgarded during serialization, and
categories extending known interfaces are merged (all members surfaced)
into the interfaces.

Differential Revision: https://reviews.llvm.org/D122774

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/lib/ExtractAPI/DeclarationFragments.cpp b/clang/lib/ExtractAPI/DeclarationFragments.cpp
index 4e0e8da..fa28fad 100644
--- a/clang/lib/ExtractAPI/DeclarationFragments.cpp
+++ b/clang/lib/ExtractAPI/DeclarationFragments.cpp
@@ -526,6 +526,25 @@ DeclarationFragmentsBuilder::getFragmentsForMacro(StringRef Name,
   return Fragments;
 }
 
+DeclarationFragments DeclarationFragmentsBuilder::getFragmentsForObjCCategory(
+    const ObjCCategoryDecl *Category) {
+  DeclarationFragments Fragments;
+
+  SmallString<128> InterfaceUSR;
+  index::generateUSRForDecl(Category->getClassInterface(), InterfaceUSR);
+
+  Fragments.append("@interface", DeclarationFragments::FragmentKind::Keyword)
+      .appendSpace()
+      .append(Category->getClassInterface()->getName(),
+              DeclarationFragments::FragmentKind::TypeIdentifier, InterfaceUSR)
+      .append(" (", DeclarationFragments::FragmentKind::Text)
+      .append(Category->getName(),
+              DeclarationFragments::FragmentKind::Identifier)
+      .append(")", DeclarationFragments::FragmentKind::Text);
+
+  return Fragments;
+}
+
 DeclarationFragments DeclarationFragmentsBuilder::getFragmentsForObjCInterface(
     const ObjCInterfaceDecl *Interface) {
   DeclarationFragments Fragments;