From a5bd7b1ac13716175d275f679bb79bdf586f3df2 Mon Sep 17 00:00:00 2001
From: Lucian Popescu <lucian.popescu@tecnico.ulisboa.pt>
Date: Mon, 12 Oct 2026 09:40:32 +0100
Subject: [PATCH] Delete abstract_structs_

---
 cpp2rust/converter/converter.cpp                 | 4 +---
 cpp2rust/converter/converter.h                   | 1 -
 cpp2rust/converter/converter_lib.cpp             | 7 +++++++
 cpp2rust/converter/converter_lib.h               | 2 ++
 cpp2rust/converter/models/converter_refcount.cpp | 6 +++---
 5 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/cpp2rust/converter/converter.cpp b/cpp2rust/converter/converter.cpp
index dc59f0d05..426ab23f4 100644
--- a/cpp2rust/converter/converter.cpp
+++ b/cpp2rust/converter/converter.cpp
@@ -30,7 +30,6 @@ std::unordered_map<std::string, std::string> Converter::inner_structs_;
 std::unordered_set<std::string> Converter::decl_ids_;
 std::unordered_set<std::string> Converter::globals_;
 std::vector<std::string> Converter::global_inits_;
-std::unordered_set<std::string> Converter::abstract_structs_;
 Converter::RecordIndex Converter::record_decls_;
 std::map<std::string, Converter::DeferredBlock> Converter::virtual_methods_;
 
@@ -318,7 +317,7 @@ bool Converter::VisitPointerType(clang::PointerType *type) {
   auto pointee_type = type->getPointeeType();
   StrCat(pointee_type.isConstQualified() ? "*const" : "*mut");
   if (pointee_type->isRecordType() &&
-      abstract_structs_.contains(GetID(pointee_type->getAsRecordDecl()))) {
+      IsAbstractUserClass(pointee_type->getAsRecordDecl())) {
     StrCat(keyword::kDyn);
   }
   return Convert(pointee_type);
@@ -4629,7 +4628,6 @@ pub fn main() {{
 }
 
 void Converter::ConvertAbstractClass(clang::CXXRecordDecl *decl) {
-  ENSURE(abstract_structs_.insert(GetID(decl)).second);
   auto trait_name = GetRecordName(decl);
   auto access_specifier_as_string = AccessSpecifierAsString(decl->getAccess());
   auto signature = std::format("{} {} trait {}", access_specifier_as_string,
diff --git a/cpp2rust/converter/converter.h b/cpp2rust/converter/converter.h
index 7d9e7b75d..bd3773230 100644
--- a/cpp2rust/converter/converter.h
+++ b/cpp2rust/converter/converter.h
@@ -952,7 +952,6 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
   };
 
   static std::unordered_set<std::string> decl_ids_;
-  static std::unordered_set<std::string> abstract_structs_;
 
   class RecordIndex {
   public:
diff --git a/cpp2rust/converter/converter_lib.cpp b/cpp2rust/converter/converter_lib.cpp
index 8cbacc4eb..01ed8b0c2 100644
--- a/cpp2rust/converter/converter_lib.cpp
+++ b/cpp2rust/converter/converter_lib.cpp
@@ -301,6 +301,13 @@ bool IsUserDefinedDecl(const clang::Decl *decl) {
          !src_mgr.isInSystemMacro(src_loc);
 }
 
+bool IsAbstractUserClass(const clang::RecordDecl *decl) {
+  auto cxx = llvm::dyn_cast<clang::CXXRecordDecl>(decl);
+  auto definition = cxx ? cxx->getDefinition() : nullptr;
+  return definition && IsUserDefinedDecl(definition) &&
+         definition->isAbstract();
+}
+
 bool RefersToUserDefinedDecl(const clang::Expr *expr) {
   expr = expr->IgnoreParenImpCasts();
   const clang::Decl *decl = nullptr;
diff --git a/cpp2rust/converter/converter_lib.h b/cpp2rust/converter/converter_lib.h
index ccbbe8dc3..00405427a 100644
--- a/cpp2rust/converter/converter_lib.h
+++ b/cpp2rust/converter/converter_lib.h
@@ -66,6 +66,8 @@ bool IsCodeUnitStringLiteral(const clang::StringLiteral *expr);
 
 bool IsUserDefinedDecl(const clang::Decl *decl);
 
+bool IsAbstractUserClass(const clang::RecordDecl *decl);
+
 bool RefersToUserDefinedDecl(const clang::Expr *expr);
 
 bool IsUnsignedArithOp(const clang::BinaryOperator *expr);
diff --git a/cpp2rust/converter/models/converter_refcount.cpp b/cpp2rust/converter/models/converter_refcount.cpp
index a9172bc13..3a47ff7ea 100644
--- a/cpp2rust/converter/models/converter_refcount.cpp
+++ b/cpp2rust/converter/models/converter_refcount.cpp
@@ -341,7 +341,7 @@ bool ConverterRefCount::VisitPointerType(clang::PointerType *type) {
   PushConversionKind push2(*this, ConversionKind::FullRefCount,
                            pointee_is_array);
   if (pointee_type->isRecordType() &&
-      abstract_structs_.contains(GetID(pointee_type->getAsRecordDecl()))) {
+      IsAbstractUserClass(pointee_type->getAsRecordDecl())) {
     StrCat("PtrDyn<dyn");
   } else {
     StrCat("Ptr<");
@@ -1507,7 +1507,7 @@ bool ConverterRefCount::VisitImplicitCastExpr(clang::ImplicitCastExpr *expr) {
       auto ptype = clang::dyn_cast<clang::PointerType>(expr->getType());
       auto pointee_type = ptype->getPointeeType()->getAsCXXRecordDecl();
 
-      if (pointee_type && abstract_structs_.contains(GetID(pointee_type))) {
+      if (pointee_type && IsAbstractUserClass(pointee_type)) {
         PushConversionKind push(*this, ConversionKind::Unboxed);
         StrCat(std::format("{}.to_dyn::<{}>(|w| w)",
                            ToString(sub_expr->IgnoreCasts()),
@@ -3222,7 +3222,7 @@ void ConverterRefCount::ConvertArrow(clang::Expr *expr) {
     auto pointee_type = expr->getType()->getPointeeType();
     // Virtual methods, which take &mut self, are called through PtrDyn.
     if (auto *record = pointee_type->getAsRecordDecl();
-        isLValue() && record && abstract_structs_.contains(GetID(record))) {
+        isLValue() && record && IsAbstractUserClass(record)) {
       StrCat(std::format("(*{}.upgrade().deref_mut())", ToString(expr)));
       SetValueFreshness(pointee_type);
       return;