[clang][ExtractAPI] Fix handling of anonymous TagDecls (#87772)

This changes the handling of anonymous TagDecls to the following rules:
- If the TagDecl is embedded in the declaration for some VarDecl (this
is the only possibility for RecordDecls), then pretend the child decls
belong to the VarDecl
- If it's an EnumDecl proceed as we did previously, i.e., embed it in
the enclosing DeclContext.

Additionally this fixes a few issues with declaration fragments not
consistently including "{ ... }" for anonymous TagDecls. To make testing
these additions easier this patch fixes some text declaration fragments
merging issues and updates tests accordingly.

rdar://121436298

1 files changed, 13 insertions, 4 deletions

diff --git a/clang/lib/ExtractAPI/DeclarationFragments.cpp b/clang/lib/ExtractAPI/DeclarationFragments.cpp
index 0a24312..9bf7950 100644
--- a/clang/lib/ExtractAPI/DeclarationFragments.cpp
+++ b/clang/lib/ExtractAPI/DeclarationFragments.cpp
@@ -396,7 +396,8 @@ DeclarationFragments DeclarationFragmentsBuilder::getFragmentsForType(
     const TagDecl *Decl = TagTy->getDecl();
     // Anonymous decl, skip this fragment.
     if (Decl->getName().empty())
-      return Fragments;
+      return Fragments.append("{ ... }",
+                              DeclarationFragments::FragmentKind::Text);
     SmallString<128> TagUSR;
     clang::index::generateUSRForDecl(Decl, TagUSR);
     return Fragments.append(Decl->getName(),
@@ -743,11 +744,16 @@ DeclarationFragmentsBuilder::getFragmentsForEnum(const EnumDecl *EnumDecl) {
 
   QualType IntegerType = EnumDecl->getIntegerType();
   if (!IntegerType.isNull())
-    Fragments.append(": ", DeclarationFragments::FragmentKind::Text)
+    Fragments.appendSpace()
+        .append(": ", DeclarationFragments::FragmentKind::Text)
         .append(
             getFragmentsForType(IntegerType, EnumDecl->getASTContext(), After))
         .append(std::move(After));
 
+  if (EnumDecl->getName().empty())
+    Fragments.appendSpace().append("{ ... }",
+                                   DeclarationFragments::FragmentKind::Text);
+
   return Fragments.appendSemicolon();
 }
 
@@ -778,9 +784,12 @@ DeclarationFragments DeclarationFragmentsBuilder::getFragmentsForRecordDecl(
   else
     Fragments.append("struct", DeclarationFragments::FragmentKind::Keyword);
 
+  Fragments.appendSpace();
   if (!Record->getName().empty())
-    Fragments.appendSpace().append(
-        Record->getName(), DeclarationFragments::FragmentKind::Identifier);
+    Fragments.append(Record->getName(),
+                     DeclarationFragments::FragmentKind::Identifier);
+  else
+    Fragments.append("{ ... }", DeclarationFragments::FragmentKind::Text);
 
   return Fragments.appendSemicolon();
 }