lucic71 · Oct 4, 2026 · Oct 4, 2026 · Oct 4, 2026 · Oct 4, 2026 · Oct 4, 2026
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -219,7 +219,17 @@ add_custom_command(
 )
 
 file(GLOB rule_subdirs CONFIGURE_DEPENDS ${PROJECT_SOURCE_DIR}/rules/*)
+file(GLOB rule_common_headers CONFIGURE_DEPENDS ${PROJECT_SOURCE_DIR}/rules/common/*.h)
+file(GLOB rule_indexer_sources CONFIGURE_DEPENDS
+     ${PROJECT_SOURCE_DIR}/cpp2rust/rule_preprocessing/*
+     ${PROJECT_SOURCE_DIR}/cpp2rust/converter/rules/rules_loader.*)
+set(_common_headers)
+foreach(_header IN LISTS rule_common_headers)
+  list(APPEND _common_headers --common-header=${_header})
+endforeach()
 set(cpp_rules_ir_outputs)
+set(cpp_rules_index_inputs)
+set(cpp_rules_index_outputs ${CMAKE_BINARY_DIR}/rules_index/c.json ${CMAKE_BINARY_DIR}/rules_index/cpp.json)
 set(rust_rules_ir_outputs)
 foreach(_rule_dir IN LISTS rule_subdirs)
   file(GLOB _cpp_srcs ${_rule_dir}/src.c ${_rule_dir}/src.cpp)
@@ -229,7 +239,7 @@ foreach(_rule_dir IN LISTS rule_subdirs)
   get_filename_component(_rule_name ${_rule_dir} NAME)
   set(_out_dir ${RULES_IR_DIR}/${_rule_name})
   set(_cpp_out ${_out_dir}/ir_src.json)
-  set(_cxxflags --cxxflags=-isystem${_rule_dir})
+  set(_cxxflags)
   set(_cxxflags_file)
   if(EXISTS ${_rule_dir}/cxxflags)
     set(_cxxflags_file ${_rule_dir}/cxxflags)
@@ -242,11 +252,15 @@ foreach(_rule_dir IN LISTS rule_subdirs)
     OUTPUT ${_cpp_out}
     COMMAND ${CMAKE_COMMAND} -E make_directory ${_out_dir}
     COMMAND $<TARGET_FILE:cpp-rule-preprocessor> --dir ${_rule_dir} --out ${_cpp_out} ${_cxxflags}
-    DEPENDS ${_cpp_srcs} ${_cxxflags_file} ${PROJECT_SOURCE_DIR}/cpp2rust/cpp_rule_preprocessor.cpp ${RUSTLS_HEADER} ${BROTLI_HEADERS}
+    DEPENDS ${_cpp_srcs} ${_cxxflags_file} ${rule_common_headers} ${PROJECT_SOURCE_DIR}/cpp2rust/rule_preprocessing/cpp_rule_preprocessor.cpp ${RUSTLS_HEADER} ${BROTLI_HEADERS}
     VERBATIM
   )
   list(APPEND cpp_rules_ir_outputs ${_cpp_out})
 
+  if(NOT _rule_name STREQUAL "builtin_types")
+    list(APPEND cpp_rules_index_inputs ${_cpp_srcs} ${_cxxflags_file})
+  endif()
+
   set(_rust_srcs)
   set(_rust_out)
   if(EXISTS ${_rule_dir}/tgt_unsafe.rs)
@@ -277,6 +291,15 @@ endforeach()
 
 add_custom_target("preprocess-cpp-rules" ALL DEPENDS ${cpp_rules_ir_outputs})
 
+add_custom_command(
+  OUTPUT ${cpp_rules_index_outputs}
+  COMMAND $<TARGET_FILE:cpp-rule-indexer> --exclude builtin_types ${_common_headers}
+  DEPENDS ${cpp_rules_index_inputs} ${rule_common_headers} ${rule_indexer_sources} ${RUSTLS_HEADER} ${BROTLI_HEADERS}
+  VERBATIM
+)
+
+add_custom_target("index-cpp-rules" ALL DEPENDS ${cpp_rules_index_outputs})
+
 add_custom_target("preprocess-rust-rules" ALL
                   DEPENDS ${rust_rules_ir_outputs})
 

diff --git a/cpp2rust/CMakeLists.txt b/cpp2rust/CMakeLists.txt
@@ -1,7 +1,8 @@
 file(GLOB_RECURSE CORE_SOURCES "*.cpp")
+file(GLOB RULE_PREPROCESSING_SOURCES "rule_preprocessing/*.cpp")
 list(REMOVE_ITEM CORE_SOURCES
     "${CMAKE_CURRENT_SOURCE_DIR}/cpp2rust.cpp"
-    "${CMAKE_CURRENT_SOURCE_DIR}/cpp_rule_preprocessor.cpp"
+    ${RULE_PREPROCESSING_SOURCES}
 )
 
 add_library(cpp2rust_core STATIC ${CORE_SOURCES})
@@ -17,6 +18,8 @@ target_compile_definitions(cpp2rust_core PUBLIC "-DCLANG_C_COMPILER=\"${CMAKE_C_
 target_compile_definitions(cpp2rust_core PUBLIC "-DCLANG_CXX_COMPILER=\"${CMAKE_CXX_COMPILER}\"")
 target_compile_definitions(cpp2rust_core PUBLIC "-DCLANG_RESOURCE_DIR=\"${LLVM_LIBRARY_DIR}/clang/${LLVM_VERSION_MAJOR}\"")
 target_compile_definitions(cpp2rust_core PUBLIC "-DCOMPAT_INCLUDE_DIR=\"${CMAKE_CURRENT_SOURCE_DIR}/compat\"")
+target_compile_definitions(cpp2rust_core PUBLIC "-DRULES_SRC_DIR=\"${PROJECT_SOURCE_DIR}/rules\"")
+target_compile_definitions(cpp2rust_core PUBLIC "-DRULES_INDEX_DIR=\"${CMAKE_BINARY_DIR}/rules_index\"")
 target_compile_definitions(cpp2rust_core PUBLIC "-DRUST_STABLE_VERSION=\"${RUST_STABLE_VERSION}\"")
 
 if (APPLE)
@@ -34,5 +37,10 @@ target_link_libraries(cpp2rust_core PUBLIC ${llvm_libs})
 add_clang_executable(cpp2rust PARTIAL_SOURCES_INTENDED cpp2rust.cpp)
 target_link_libraries(cpp2rust PRIVATE cpp2rust_core)
 
-add_clang_executable(cpp-rule-preprocessor PARTIAL_SOURCES_INTENDED cpp_rule_preprocessor.cpp)
+add_clang_executable(cpp-rule-preprocessor PARTIAL_SOURCES_INTENDED
+    rule_preprocessing/cpp_rule_preprocessor.cpp)
 target_link_libraries(cpp-rule-preprocessor PRIVATE cpp2rust_core)
+
+add_clang_executable(cpp-rule-indexer PARTIAL_SOURCES_INTENDED
+    rule_preprocessing/cpp_rule_indexer.cpp)
+target_link_libraries(cpp-rule-indexer PRIVATE cpp2rust_core)
diff --git a/cpp2rust/ast_consumer.cpp b/cpp2rust/ast_consumer.cpp
@@ -3,10 +3,16 @@
 
 #include "ast_consumer.h"
 
+#include <llvm/Support/ErrorHandling.h>
+
 #include "converter/converter.h"
 
 namespace cpp2rust {
 void ASTConsumer::HandleTranslationUnit(clang::ASTContext &ctx) {
+  if (CI_.getDiagnostics().hasErrorOccurred()) {
+    llvm::report_fatal_error(
+        "the translation unit and its loaded rules do not compile");
+  }
   auto converter = CreateConverter(rs_code_, ctx, model_, rules_dir_);
   converter->SetSema(CI_.getSema());
   if (first_) {

diff --git a/cpp2rust/converter/converter.cpp b/cpp2rust/converter/converter.cpp
@@ -965,49 +965,7 @@ bool Converter::VisitCXXRecordDecl(clang::CXXRecordDecl *decl) {
 }
 
 void Converter::DefineImplicitMembers(clang::CXXRecordDecl *decl) {
-  clang::Scope tu_scope(nullptr, clang::Scope::DeclScope,
-                        sema_->getDiagnostics());
-  tu_scope.setEntity(ctx_.getTranslationUnitDecl());
-  auto *saved_tu_scope = std::exchange(sema_->TUScope, &tu_scope);
-  sema_->ForceDeclarationOfImplicitMembers(decl);
-  for (auto ctor : decl->ctors()) {
-    if (ctor->isCopyConstructor() && ctor->isImplicit() &&
-        !ctor->doesThisDeclarationHaveABody() && !ctor->isDeleted()) {
-      sema_->DefineImplicitCopyConstructor(decl->getLocation(), ctor);
-    }
-    if (ctor->isMoveConstructor() && !ctor->isUserProvided() &&
-        !ctor->doesThisDeclarationHaveABody() && !ctor->isDeleted() &&
-        !HasDefaultedCopyConstructor(decl)) {
-      sema_->DefineImplicitMoveConstructor(decl->getLocation(), ctor);
-    }
-  }
-  for (auto *method : decl->methods()) {
-    if (method->isMoveAssignmentOperator() && !method->isUserProvided() &&
-        !method->doesThisDeclarationHaveABody() && !method->isDeleted() &&
-        !HasDefaultedCopyAssignment(decl)) {
-      sema_->DefineImplicitMoveAssignment(decl->getLocation(), method);
-    }
-  }
-  auto define_defaulted_comparison = [&](clang::FunctionDecl *fn) {
-    if (!fn || !IsComparisonOperator(fn) || !fn->isDefaulted() ||
-        fn->doesThisDeclarationHaveABody()) {
-      return;
-    }
-#if CLANG_VERSION_MAJOR >= 24
-    auto kind = fn->getDefaultedComparisonKind();
-#else
-    auto kind = sema_->getDefaultedComparisonKind(fn);
-#endif
-    sema_->DefineDefaultedComparison(decl->getLocation(), fn, kind);
-  };
-  for (auto *method : decl->methods()) {
-    define_defaulted_comparison(method);
-  }
-  for (auto *friend_decl : decl->friends()) {
-    define_defaulted_comparison(clang::dyn_cast_or_null<clang::FunctionDecl>(
-        friend_decl->getFriendDecl()));
-  }
-  sema_->TUScope = saved_tu_scope;
+  cpp2rust::DefineImplicitMembers(*sema_, decl);
 }
 
 bool Converter::VisitCXXMethodDecl(clang::CXXMethodDecl *decl) {

diff --git a/cpp2rust/converter/converter_lib.cpp b/cpp2rust/converter/converter_lib.cpp
@@ -3,6 +3,7 @@
 
 #include "converter/converter_lib.h"
 
+#include <clang/AST/DeclFriend.h>
 #include <clang/AST/DeclTemplate.h>
 #include <clang/AST/ExprCXX.h>
 #include <clang/AST/ExprConcepts.h>
@@ -1270,6 +1271,52 @@ bool IsComparisonOperator(const clang::FunctionDecl *fn) {
   }
 }
 
+void DefineImplicitMembers(clang::Sema &sema, clang::CXXRecordDecl *decl) {
+  clang::Scope tu_scope(nullptr, clang::Scope::DeclScope,
+                        sema.getDiagnostics());
+  tu_scope.setEntity(sema.Context.getTranslationUnitDecl());
+  auto *saved_tu_scope = std::exchange(sema.TUScope, &tu_scope);
+  sema.ForceDeclarationOfImplicitMembers(decl);
+  for (auto ctor : decl->ctors()) {
+    if (ctor->isCopyConstructor() && ctor->isImplicit() &&
+        !ctor->doesThisDeclarationHaveABody() && !ctor->isDeleted()) {
+      sema.DefineImplicitCopyConstructor(decl->getLocation(), ctor);
+    }
+    if (ctor->isMoveConstructor() && !ctor->isUserProvided() &&
+        !ctor->doesThisDeclarationHaveABody() && !ctor->isDeleted() &&
+        !HasDefaultedCopyConstructor(decl)) {
+      sema.DefineImplicitMoveConstructor(decl->getLocation(), ctor);
+    }
+  }
+  for (auto *method : decl->methods()) {
+    if (method->isMoveAssignmentOperator() && !method->isUserProvided() &&
+        !method->doesThisDeclarationHaveABody() && !method->isDeleted() &&
+        !HasDefaultedCopyAssignment(decl)) {
+      sema.DefineImplicitMoveAssignment(decl->getLocation(), method);
+    }
+  }
+  auto define_defaulted_comparison = [&](clang::FunctionDecl *fn) {
+    if (!fn || !IsComparisonOperator(fn) || !fn->isDefaulted() ||
+        fn->doesThisDeclarationHaveABody()) {
+      return;
+    }
+#if CLANG_VERSION_MAJOR >= 24
+    auto kind = fn->getDefaultedComparisonKind();
+#else
+    auto kind = sema.getDefaultedComparisonKind(fn);
+#endif
+    sema.DefineDefaultedComparison(decl->getLocation(), fn, kind);
+  };
+  for (auto *method : decl->methods()) {
+    define_defaulted_comparison(method);
+  }
+  for (auto *friend_decl : decl->friends()) {
+    define_defaulted_comparison(clang::dyn_cast_or_null<clang::FunctionDecl>(
+        friend_decl->getFriendDecl()));
+  }
+  sema.TUScope = saved_tu_scope;
+}
+
 bool IsEmittableMethod(clang::CXXMethodDecl *method) {
   if (method->isDeleted()) {
     return false;

diff --git a/cpp2rust/converter/converter_lib.h b/cpp2rust/converter/converter_lib.h
@@ -126,6 +126,9 @@ bool IsConvertibleCXXRecordDecl(const clang::CXXRecordDecl *decl);
 bool IsConvertibleCXXMethodDecl(const clang::CXXMethodDecl *decl);
 
 bool IsComparisonOperator(const clang::FunctionDecl *fn);
+
+void DefineImplicitMembers(clang::Sema &sema, clang::CXXRecordDecl *decl);
+
 bool IsEmittableMethod(clang::CXXMethodDecl *method);
 
 bool IsMethodOnPtr(const clang::CXXMethodDecl *method);

diff --git a/cpp2rust/converter/printer.cpp b/cpp2rust/converter/printer.cpp
@@ -134,7 +134,20 @@ std::string ToString(clang::ASTContext &ctx, clang::QualType qual_type,
     }
     if (const auto *typedef_type = t->getAs<clang::TypedefType>()) {
       if (t.getCanonicalType()->isBuiltinType()) {
-        return typedef_type->getDecl()->getNameAsString();
+        auto decl = typedef_type->getDecl();
+        if (auto record =
+                clang::dyn_cast<clang::RecordDecl>(decl->getDeclContext());
+            record && !record->isDependentContext()) {
+          return ToString(ctx, ctx.getCanonicalTagType(record)) +
+                 "::" + decl->getNameAsString();
+        }
+        if (decl->getDeclContext()->getRedeclContext()->isNamespace()) {
+          std::string name;
+          llvm::raw_string_ostream os(name);
+          decl->printQualifiedName(os, getPrintPolicy(ctx));
+          return name;
+        }
+        return decl->getNameAsString();
       }
     } else if (const auto *predef = t->getAs<clang::PredefinedSugarType>()) {
       return predef->getIdentifier()->getName().str();