🎨 Reorganize QDMI Codebase

bindings/fomac/fomac.cpp

@@ -10,7 +10,7 @@
 
 #include "fomac/FoMaC.hpp"
 
-#include "qdmi/Driver.hpp"
+#include "../../include/mqt-core/qdmi/driver/Driver.hpp"
 
 #include <nanobind/nanobind.h>
 #include <nanobind/operators.h>

bindings/na/register_fomac.cpp

@@ -10,7 +10,7 @@
 
 #include "fomac/FoMaC.hpp"
 #include "na/fomac/Device.hpp"
-#include "qdmi/na/Generator.hpp"
+#include "qdmi/devices/na/Generator.hpp"
 
 #include <nanobind/nanobind.h>
 #include <nanobind/operators.h>

include/mqt-core/fomac/FoMaC.hpp

@@ -10,7 +10,7 @@
 
 #pragma once
 
-#include "qdmi/Common.hpp"
+#include "../qdmi/devices/common/Common.hpp"
 
 #include <algorithm>
 #include <complex>

include/mqt-core/na/fomac/Device.hpp

@@ -11,7 +11,7 @@
 #pragma once
 
 #include "fomac/FoMaC.hpp"
-#include "qdmi/na/Generator.hpp"
+#include "qdmi/devices/na/Generator.hpp"
 
 // NOLINTNEXTLINE(misc-include-cleaner)
 #include <nlohmann/json.hpp>

include/mqt-core/qdmi/Common.hpp → include/mqt-core/qdmi/devices/common/Common.hpp

@@ -19,9 +19,35 @@
 #include <string>
 
 namespace qdmi {
+template <class Concrete> class Singleton {
+protected:
+  /// @brief Protected constructor to enforce the singleton pattern.
+  Singleton() = default;
+
+public:
+  // Default move constructor and move assignment operator.
+  Singleton(Singleton&&) = default;
+  Singleton& operator=(Singleton&&) = default;
+  // Delete copy constructor and assignment operator to enforce singleton.
+  Singleton(const Singleton&) = delete;
+  Singleton& operator=(const Singleton&) = delete;
+
+  /// @brief Destructor for the Device class.
+  virtual ~Singleton() = default;
+
+  /// @returns the singleton instance of the Device class.
+  [[nodiscard]] static auto get() -> Concrete& {
+    // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+    static auto* instance = new Concrete();
+    // The instance is intentionally leaked to avoid static deinitialization
+    // issues (cf. static (de)initialization order fiasco)
+    return *instance;
+  }
+};
+
 /**
  * @brief Function used to mark unreachable code
- * @details Uses compiler specific extensions if possible. Even if no extension
+ * @details Uses compiler-specific extensions if possible. Even if no extension
  * is used, undefined behavior is still raised by an empty function body and the
  * noreturn attribute.
  */

include/mqt-core/qdmi/dd/Device.hpp → include/mqt-core/qdmi/devices/dd/Device.hpp

@@ -26,12 +26,15 @@
 #include <map>
 #include <memory>
 #include <mutex>
+#include <qdmi/devices/common/Common.hpp>
 #include <random>
 #include <string>
 #include <unordered_map>
 
 namespace qdmi::dd {
-class Device final {
+class Device final : public Singleton<Device> {
+  friend Singleton;
+
   /// Provides access to the device name.
   std::string name_;
 
@@ -64,18 +67,8 @@ class Device final {
   Device();
 
 public:
-  // Default move constructor and move assignment operator.
-  Device(Device&&) = delete;
-  Device& operator=(Device&&) = delete;
-  // Delete copy constructor and assignment operator to enforce singleton.
-  Device(const Device&) = delete;
-  Device& operator=(const Device&) = delete;
-
   /// @brief Destructor for the Device class.
-  ~Device() = default;
-
-  /// @returns the singleton instance of the Device class.
-  [[nodiscard]] static auto get() -> Device&;
+  ~Device() override = default;
 
   /**
    * @brief Allocates a new device session.

include/mqt-core/qdmi/na/Device.hpp → include/mqt-core/qdmi/devices/na/Device.hpp

@@ -20,14 +20,17 @@
 #include <cstdint>
 #include <memory>
 #include <optional>
+#include <qdmi/devices/common/Common.hpp>
 #include <string>
 #include <unordered_map>
 #include <utility>
 #include <variant>
 #include <vector>
 
 namespace qdmi::na {
-class Device final {
+class Device final : public Singleton<Device> {
+  friend Singleton;
+
   /// @brief Provides access to the device name.
   std::string name_;
 
@@ -69,18 +72,8 @@ class Device final {
   Device();
 
 public:
-  // Default move constructor and move assignment operator.
-  Device(Device&&) = default;
-  Device& operator=(Device&&) = default;
-  // Delete copy constructor and assignment operator to enforce singleton.
-  Device(const Device&) = delete;
-  Device& operator=(const Device&) = delete;
-
   /// @brief Destructor for the Device class.
-  ~Device() = default;
-
-  /// @returns the singleton instance of the Device class.
-  [[nodiscard]] static auto get() -> Device&;
+  ~Device() override = default;
 
   /**
    * @brief Allocates a new device session.

include/mqt-core/qdmi/sc/Device.hpp → include/mqt-core/qdmi/devices/sc/Device.hpp

@@ -19,14 +19,17 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <qdmi/devices/common/Common.hpp>
 #include <string>
 #include <unordered_map>
 #include <utility>
 #include <variant>
 #include <vector>
 
 namespace qdmi::sc {
-class Device final {
+class Device final : public Singleton<Device> {
+  friend Singleton;
+
   /// @brief Provides access to the device name.
   std::string name_;
 
@@ -51,18 +54,8 @@ class Device final {
   Device();
 
 public:
-  // Delete move constructor and move assignment operator.
-  Device(Device&&) = delete;
-  Device& operator=(Device&&) = delete;
-  // Delete copy constructor and assignment operator to enforce singleton.
-  Device(const Device&) = delete;
-  Device& operator=(const Device&) = delete;
-
   /// @brief Destructor for the Device class.
-  ~Device();
-
-  /// @returns the singleton instance of the Device class.
-  [[nodiscard]] static auto get() -> Device&;
+  ~Device() override;
 
   /**
    * @brief Allocates a new device session.

src/fomac/FoMaC.cpp

@@ -10,7 +10,7 @@
 
 #include "fomac/FoMaC.hpp"
 
-#include "qdmi/Common.hpp"
+#include "../../include/mqt-core/qdmi/devices/common/Common.hpp"
 
 #include <algorithm>
 #include <complex>

src/na/fomac/Device.cpp

@@ -12,7 +12,7 @@
 
 #include "fomac/FoMaC.hpp"
 #include "ir/Definitions.hpp"
-#include "qdmi/na/Generator.hpp"
+#include "qdmi/devices/na/Generator.hpp"
 
 #include <algorithm>
 #include <array>

src/qdmi/CMakeLists.txt

@@ -6,56 +6,8 @@
 #
 # Licensed under the MIT License
 
-set(TARGET_NAME ${MQT_CORE_TARGET_NAME}-qdmi-common)
-
-if(NOT TARGET ${TARGET_NAME})
-  # Add common library
-  add_mqt_core_library(${TARGET_NAME} ALIAS_NAME QDMICommon)
-
-  # Add sources to target
-  target_sources(${TARGET_NAME} PRIVATE Common.cpp)
-
-  # Add headers using file sets
-  target_sources(${TARGET_NAME} PUBLIC FILE_SET HEADERS BASE_DIRS ${MQT_CORE_INCLUDE_BUILD_DIR}
-                                       FILES ${MQT_CORE_INCLUDE_BUILD_DIR}/qdmi/Common.hpp)
-
-  # Add link libraries
-  target_link_libraries(
-    ${TARGET_NAME}
-    PUBLIC qdmi::qdmi
-    PRIVATE qdmi::qdmi_project_warnings)
-
-  # add to list of MQT core targets
-  list(APPEND MQT_CORE_TARGETS ${TARGET_NAME})
-endif()
-
-add_subdirectory(dd)
-add_subdirectory(sc)
-add_subdirectory(na)
-
-set(TARGET_NAME ${MQT_CORE_TARGET_NAME}-qdmi-driver)
-
-if(NOT TARGET ${TARGET_NAME})
-  # Add driver library
-  add_mqt_core_library(${TARGET_NAME} ALIAS_NAME QDMIDriver)
-
-  # Add sources to target
-  target_sources(${TARGET_NAME} PRIVATE Driver.cpp)
-
-  # Add headers using file sets
-  target_sources(${TARGET_NAME} PUBLIC FILE_SET HEADERS BASE_DIRS ${MQT_CORE_INCLUDE_BUILD_DIR}
-                                       FILES ${MQT_CORE_INCLUDE_BUILD_DIR}/qdmi/Driver.hpp)
-
-  # Add link libraries
-  target_link_libraries(
-    ${TARGET_NAME}
-    PUBLIC qdmi::qdmi MQT::CoreQDMICommon
-    PRIVATE MQT::CoreQDMINaDevice MQT::CoreQDMIScDevice MQT::CoreQDMI_DDSIM_Device
-            qdmi::qdmi_project_warnings spdlog::spdlog ${CMAKE_DL_LIBS})
-
-  # add to list of MQT core targets
-  list(APPEND MQT_CORE_TARGETS ${TARGET_NAME})
-endif()
+add_subdirectory(devices)
+add_subdirectory(driver)
 
 set(MQT_CORE_TARGETS
     ${MQT_CORE_TARGETS}

src/qdmi/devices/CMakeLists.txt

@@ -0,0 +1,16 @@
+# Copyright (c) 2023 - 2026 Chair for Design Automation, TUM
+# Copyright (c) 2025 - 2026 Munich Quantum Software Company GmbH
+# All rights reserved.
+#
+# SPDX-License-Identifier: MIT
+#
+# Licensed under the MIT License
+
+add_subdirectory(common)
+add_subdirectory(dd)
+add_subdirectory(sc)
+add_subdirectory(na)
+
+set(MQT_CORE_TARGETS
+    ${MQT_CORE_TARGETS}
+    PARENT_SCOPE)

src/qdmi/devices/common/CMakeLists.txt

@@ -0,0 +1,35 @@
+# Copyright (c) 2023 - 2026 Chair for Design Automation, TUM
+# Copyright (c) 2025 - 2026 Munich Quantum Software Company GmbH
+# All rights reserved.
+#
+# SPDX-License-Identifier: MIT
+#
+# Licensed under the MIT License
+
+set(TARGET_NAME ${MQT_CORE_TARGET_NAME}-qdmi-common)
+
+if(NOT TARGET ${TARGET_NAME})
+  # Add common library
+  add_mqt_core_library(${TARGET_NAME} ALIAS_NAME QDMICommon)
+
+  # Add sources to target
+  target_sources(${TARGET_NAME} PRIVATE Common.cpp)
+
+  # Add headers using file sets
+  target_sources(
+    ${TARGET_NAME} PUBLIC FILE_SET HEADERS BASE_DIRS ${MQT_CORE_INCLUDE_BUILD_DIR} FILES
+                          ${MQT_CORE_INCLUDE_BUILD_DIR}/qdmi/devices/common/Common.hpp)
+
+  # Add link libraries
+  target_link_libraries(
+    ${TARGET_NAME}
+    PUBLIC qdmi::qdmi
+    PRIVATE qdmi::qdmi_project_warnings)
+
+  # add to list of MQT core targets
+  list(APPEND MQT_CORE_TARGETS ${TARGET_NAME})
+endif()
+
+set(MQT_CORE_TARGETS
+    ${MQT_CORE_TARGETS}
+    PARENT_SCOPE)

src/qdmi/Common.cpp → src/qdmi/devices/common/Common.cpp

@@ -12,7 +12,7 @@
 /// @brief Common definitions and utilities for working with QDMI in C++.
 /// @note This file will be upstreamed to the QDMI core library in the future.
 
-#include "qdmi/Common.hpp"
+#include "qdmi/devices/common/Common.hpp"
 
 #include <iostream>
 #include <qdmi/constants.h>

src/qdmi/dd/CMakeLists.txt → src/qdmi/devices/dd/CMakeLists.txt

@@ -34,7 +34,7 @@ if(NOT TARGET ${TARGET_NAME})
            ${MQT_CORE_INCLUDE_BUILD_DIR}
            ${CMAKE_CURRENT_BINARY_DIR}/include
            FILES
-           ${MQT_CORE_INCLUDE_BUILD_DIR}/qdmi/dd/Device.hpp
+           ${MQT_CORE_INCLUDE_BUILD_DIR}/qdmi/devices/dd/Device.hpp
            ${QDMI_HDRS})
 
   # Add link libraries
@@ -48,9 +48,7 @@ if(NOT TARGET ${TARGET_NAME})
   set_target_properties(${TARGET_NAME} PROPERTIES POSITION_INDEPENDENT_CODE ON)
 
   # Add to list of MQT Core targets
-  set(MQT_CORE_TARGETS
-      ${MQT_CORE_TARGETS} ${TARGET_NAME}
-      PARENT_SCOPE)
+  list(APPEND MQT_CORE_TARGETS ${TARGET_NAME})
 
   # Make QDMI version available
   target_compile_definitions(${TARGET_NAME} PRIVATE QDMI_VERSION="${QDMI_VERSION}")
@@ -59,3 +57,7 @@ if(NOT TARGET ${TARGET_NAME})
   # in the tests
   add_library(qdmi::mqt_ddsim_device ALIAS ${TARGET_NAME})
 endif()
+
+set(MQT_CORE_TARGETS
+    ${MQT_CORE_TARGETS}
+    PARENT_SCOPE)

src/qdmi/dd/Device.cpp → src/qdmi/devices/dd/Device.cpp

@@ -12,7 +12,7 @@
  * @brief The MQT QDMI device implementation for its DD-based simulator.
  */
 
-#include "qdmi/dd/Device.hpp"
+#include "qdmi/devices/dd/Device.hpp"
 
 #include "circuit_optimizer/CircuitOptimizer.hpp"
 #include "dd/DDDefinitions.hpp"
@@ -22,7 +22,7 @@
 #include "ir/QuantumComputation.hpp"
 #include "mqt_ddsim_qdmi/device.h"
 #include "qasm3/Importer.hpp"
-#include "qdmi/Common.hpp"
+#include "qdmi/devices/common/Common.hpp"
 
 #include <algorithm>
 #include <array>
@@ -149,13 +149,6 @@ namespace qdmi::dd {
 Device::Device()
     : name_("MQT Core DDSIM QDMI Device"),
       qubitsNum_(std::numeric_limits<::dd::Qubit>::max()) {}
-auto Device::get() -> Device& {
-  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
-  static auto* instance = new Device();
-  // The instance is intentionally leaked to avoid static deinitialization
-  // issues (cf. static (de)initialization order fiasco)
-  return *instance;
-}
 auto Device::sessionAlloc(MQT_DDSIM_QDMI_Device_Session* session)
     -> QDMI_STATUS {
   if (session == nullptr) {

src/qdmi/na/App.cpp → src/qdmi/devices/na/App.cpp

@@ -8,7 +8,7 @@
  * Licensed under the MIT License
  */
 
-#include "qdmi/na/Generator.hpp"
+#include "qdmi/devices/na/Generator.hpp"
 
 #include <cstddef>
 #include <cstdint>