[WIP] extract comments

Author: Vipul-Cariappa

include/CppInterOp/CppInterOp.h

@@ -375,6 +375,8 @@ CPPINTEROP_API bool IsVariable(TCppScope_t scope);
 /// namespace, variable, or a function).
 CPPINTEROP_API std::string GetName(TCppScope_t klass);
 
+CPPINTEROP_API std::string GetDocString(TCppScope_t scope);
+
 /// This is similar to GetName() function, but besides
 /// the name, it also gets the template arguments.
 CPPINTEROP_API std::string GetCompleteName(TCppScope_t klass);

lib/CppInterOp/CppInterOp.cpp

@@ -12,6 +12,7 @@
 #include "Compatibility.h"
 
 #include "clang/AST/Attrs.inc"
+#include "clang/AST/Comment.h"
 #include "clang/AST/CXXInheritance.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclAccessPair.h"
@@ -613,6 +614,15 @@ bool IsVariable(TCppScope_t scope) {
   return llvm::isa_and_nonnull<clang::VarDecl>(D);
 }
 
+std::string GetDocString(TCppScope_t scope) {
+  auto *D = static_cast<Decl*>(scope);
+  auto &AST = getASTContext(D);
+  const clang::RawComment *Comment = AST.getRawCommentForAnyRedecl(D);
+  if (!Comment)
+    return "";
+  return Comment->getFormattedText(AST.getSourceManager(), AST.getDiagnostics());
+}
+
 std::string GetName(TCppType_t klass) {
   auto* D = (clang::NamedDecl*)klass;