⬆️ update mqt-core (#337)

## Description

This PR updates the mqt-core submodule and brings in some further
advancements from #355.
Specifically, it switches to using `FetchContent` for obtaining
`mqt-core`.
Per default, it is pointed to the vendored submodule via an overridable
CMake variable.

## Checklist:

<!---
This checklist serves as a reminder of a couple of things that ensure
your pull request will be merged swiftly.
-->

- [x] The pull request only contains commits that are related to it.
- [x] I have added appropriate tests and documentation.
- [x] I have made sure that all CI jobs on GitHub pass.
- [x] The pull request introduces no new warnings and follows the
project's style guidelines.

Author: burgholzer

.gitmodules

@@ -2,13 +2,3 @@
 	path = extern/mqt-core
 	url = https://github.com/cda-tum/mqt-core.git
     branch = main
-[submodule "extern/taskflow"]
-	path = extern/taskflow
-	url = https://github.com/taskflow/taskflow.git
-	branch = master
-	shallow = true
-[submodule "extern/cxxopts"]
-	path = extern/cxxopts
-	url = https://github.com/jarro2783/cxxopts.git
-	branch = master
-	shallow = true

.pre-commit-config.yaml

@@ -72,6 +72,8 @@ repos:
     hooks:
       - id: cmake-format
         additional_dependencies: [pyyaml]
+        types: [file]
+        files: (\.cmake|CMakeLists.txt)(.in)?$
 
   # Clang-format the C++ part of the code base automatically
   - repo: https://github.com/pre-commit/mirrors-clang-format

CMakeLists.txt

@@ -1,42 +1,34 @@
 # set required cmake version
-cmake_minimum_required(VERSION 3.19...3.27)
+cmake_minimum_required(VERSION 3.19...3.28)
 
 project(
-  ddsim
+  mqt-ddsim
   LANGUAGES CXX
-  DESCRIPTION "MQT DDSIM - A quantum simulator based on decision diagrams")
-
-# check whether `modulename` is correctly cloned in the `extern` directory.
-macro(CHECK_SUBMODULE_PRESENT modulename)
-  if(NOT EXISTS "${PROJECT_SOURCE_DIR}/extern/${modulename}/CMakeLists.txt")
-    message(
-      FATAL_ERROR
-        "${modulename} submodule not cloned properly. \
-        Please run `git submodule update --init --recursive` \
-        from the main project directory")
-  endif()
-endmacro()
-
-check_submodule_present(mqt-core)
-check_submodule_present(taskflow)
+  DESCRIPTION
+    "MQT DDSIM - A quantum circuit simulator based on decision diagrams")
 
 option(BUILD_MQT_DDSIM_TESTS "Also build tests for the MQT DDSIM project" ON)
 option(BUILD_MQT_DDSIM_BINDINGS "Build the MQT DDSIM Python bindings" OFF)
+option(BUILD_MQT_DDSIM_CLI "Build the MQT DDSIM command line interface" ON)
+
 if(BUILD_MQT_DDSIM_BINDINGS)
   # ensure that the BINDINGS option is set
   set(BINDINGS
       ON
-      CACHE BOOL "Enable settings related to Python bindings" FORCE)
-  # cmake-lint: disable=C0103
+      CACHE INTERNAL "Enable settings related to Python bindings")
+  # Some common settings for finding Python
   set(Python_FIND_VIRTUALENV
       FIRST
       CACHE STRING "Give precedence to virtualenvs when searching for Python")
-  # cmake-lint: disable=C0103
+  set(Python_FIND_FRAMEWORK
+      LAST
+      CACHE STRING "Prefer Brew/Conda to Apple framework Python")
   set(Python_ARTIFACTS_INTERACTIVE
       ON
       CACHE
         BOOL
         "Prevent multiple searches for Python and instead cache the results.")
+
   # top-level call to find Python
   find_package(
     Python 3.8 REQUIRED
@@ -46,6 +38,9 @@ endif()
 
 include(cmake/ExternalDependencies.cmake)
 
+# set the include directory for the build tree
+set(MQT_DDSIM_INCLUDE_BUILD_DIR "${CMAKE_CURRENT_SOURCE_DIR}/include")
+
 add_subdirectory(src)
 
 if(BUILD_MQT_DDSIM_TESTS)
@@ -54,7 +49,6 @@ if(BUILD_MQT_DDSIM_TESTS)
   add_subdirectory(test)
 endif()
 
-if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
-  check_submodule_present(cxxopts)
+if(BUILD_MQT_DDSIM_CLI)
   add_subdirectory(apps)
 endif()

apps/CMakeLists.txt

@@ -1,30 +1,16 @@
-add_subdirectory("${PROJECT_SOURCE_DIR}/extern/cxxopts" "extern/cxxopts"
-                 EXCLUDE_FROM_ALL)
-# the following sets the SYSTEM flag for the include dirs of the cxxopts libs to
-# cmake-lint: disable=C0307
-set_target_properties(
-  cxxopts PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES
-                     $<TARGET_PROPERTY:cxxopts,INTERFACE_INCLUDE_DIRECTORIES>)
-
 # macro to add a executable with the given libraries
 macro(ADD_SIM_EXECUTABLE appname)
-  add_executable(${PROJECT_NAME}_${appname}
-                 ${CMAKE_CURRENT_SOURCE_DIR}/${appname}.cpp)
-  target_link_libraries(${PROJECT_NAME}_${appname} PRIVATE ${PROJECT_NAME}
-                                                           ${ARGN})
+  add_executable(mqt-ddsim-${appname} ${appname}.cpp)
+  target_link_libraries(mqt-ddsim-${appname} PRIVATE MQT::DDSim ${ARGN})
 endmacro()
 
-set(THREADS_PREFER_PTHREAD_FLAG ON)
-find_package(Threads)
-link_libraries(Threads::Threads)
-
 add_sim_executable(simple cxxopts::cxxopts)
 add_sim_executable(primebases cxxopts::cxxopts)
 if(Threads_FOUND)
   add_sim_executable(noise_aware cxxopts::cxxopts)
-  target_link_libraries(${PROJECT_NAME}_noise_aware PUBLIC Threads::Threads)
+  target_link_libraries(mqt-ddsim-noise_aware PRIVATE Threads::Threads)
 endif()
-find_package(OpenCV QUIET)
+
 if(OpenCV_FOUND)
   add_sim_executable(frqi cxxopts::cxxopts ${OpenCV_LIBRARIES})
 endif()

cmake/ExternalDependencies.cmake

@@ -3,6 +3,49 @@
 include(FetchContent)
 set(FETCH_PACKAGES "")
 
+if(BUILD_MQT_DDSIM_BINDINGS)
+  if(NOT SKBUILD)
+    # Manually detect the installed pybind11 package.
+    execute_process(
+      COMMAND "${Python_EXECUTABLE}" -m pybind11 --cmakedir
+      OUTPUT_STRIP_TRAILING_WHITESPACE
+      OUTPUT_VARIABLE pybind11_DIR)
+
+    # Add the detected directory to the CMake prefix path.
+    list(APPEND CMAKE_PREFIX_PATH "${pybind11_DIR}")
+  endif()
+
+  # add pybind11 library
+  find_package(pybind11 CONFIG REQUIRED)
+endif()
+
+set(FETCHCONTENT_SOURCE_DIR_MQT-CORE
+    ${PROJECT_SOURCE_DIR}/extern/mqt-core
+    CACHE
+      PATH
+      "Path to the source directory of the mqt-core library. This variable is used by FetchContent to download the library if it is not already available."
+)
+set(MQT_CORE_VERSION
+    2.2.2
+    CACHE STRING "MQT Core version")
+if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.24)
+  FetchContent_Declare(
+    mqt-core
+    GIT_REPOSITORY https://github.com/cda-tum/mqt-core.git
+    GIT_TAG v${MQT_CORE_VERSION}
+    FIND_PACKAGE_ARGS ${MQT_CORE_VERSION})
+  list(APPEND FETCH_PACKAGES mqt-core)
+else()
+  find_package(mqt-core ${MQT_CORE_VERSION} QUIET)
+  if(NOT mqt-core_FOUND)
+    FetchContent_Declare(
+      mqt-core
+      GIT_REPOSITORY https://github.com/cda-tum/mqt-core.git
+      GIT_TAG v${MQT_CORE_VERSION})
+    list(APPEND FETCH_PACKAGES mqt-core)
+  endif()
+endif()
+
 if(BUILD_MQT_DDSIM_TESTS)
   set(gtest_force_shared_crt
       ON
@@ -26,5 +69,75 @@ if(BUILD_MQT_DDSIM_TESTS)
   endif()
 endif()
 
+set(TF_BUILD_TESTS
+    OFF
+    CACHE INTERNAL "")
+set(TF_BUILD_EXAMPLES
+    OFF
+    CACHE INTERNAL "")
+set(TF_BUILD_PROFILER
+    OFF
+    CACHE INTERNAL "")
+set(TF_VERSION
+    3.6.0
+    CACHE STRING "Taskflow version")
+set(TF_URL
+    https://github.com/taskflow/taskflow/archive/refs/tags/v${TF_VERSION}.tar.gz
+)
+if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.24)
+  FetchContent_Declare(taskflow URL ${TF_URL} FIND_PACKAGE_ARGS)
+  list(APPEND FETCH_PACKAGES taskflow)
+else()
+  find_package(taskflow ${TF_VERSION} QUIET)
+  if(NOT taskflow_FOUND)
+    FetchContent_Declare(taskflow URL ${TF_URL})
+    list(APPEND FETCH_PACKAGES taskflow)
+  endif()
+endif()
+
+if(BUILD_MQT_DDSIM_CLI)
+  set(THREADS_PREFER_PTHREAD_FLAG ON)
+  find_package(Threads)
+  link_libraries(Threads::Threads)
+
+  find_package(OpenCV QUIET)
+
+  set(CXXOPTS_VERSION
+      3.1.1
+      CACHE STRING "cxxopts version")
+  set(CXXOPTS_URL
+      https://github.com/jarro2783/cxxopts/archive/refs/tags/v${CXXOPTS_VERSION}.tar.gz
+  )
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.24)
+    FetchContent_Declare(cxxopts URL ${CXXOPTS_URL} FIND_PACKAGE_ARGS
+                                     ${CXXOPTS_VERSION})
+    list(APPEND FETCH_PACKAGES cxxopts)
+  else()
+    find_package(cxxopts ${CXXOPTS_VERSION} QUIET)
+    if(NOT cxxopts_FOUND)
+      FetchContent_Declare(cxxopts URL ${CXXOPTS_URL})
+      list(APPEND FETCH_PACKAGES cxxopts)
+    endif()
+  endif()
+endif()
+
+if(BUILD_MQT_DDSIM_BINDINGS)
+  # add pybind11_json library
+  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.24)
+    FetchContent_Declare(
+      pybind11_json
+      GIT_REPOSITORY https://github.com/pybind/pybind11_json
+      FIND_PACKAGE_ARGS)
+    list(APPEND FETCH_PACKAGES pybind11_json)
+  else()
+    find_package(pybind11_json QUIET)
+    if(NOT pybind11_json_FOUND)
+      FetchContent_Declare(
+        pybind11_json GIT_REPOSITORY https://github.com/pybind/pybind11_json)
+      list(APPEND FETCH_PACKAGES pybind11_json)
+    endif()
+  endif()
+endif()
+
 # Make all declared dependencies available.
 FetchContent_MakeAvailable(${FETCH_PACKAGES})

extern/cxxopts

@@ -12,7 +12,7 @@
 if TYPE_CHECKING:
     from collections.abc import Sequence
 
-nox.options.sessions = ["lint", "pylint", "tests"]
+nox.options.sessions = ["lint", "tests"]
 
 PYTHON_ALL_VERSIONS = ["3.8", "3.9", "3.10", "3.11", "3.12"]
 

extern/mqt-core

@@ -34,12 +34,13 @@ classifiers = [
 ]
 requires-python = ">=3.8"
 dependencies = [
-    "qiskit-terra>=0.22.1"
+    "qiskit[qasm3-import]>=0.45.0"
 ]
 dynamic = ["version"]
 
 [project.optional-dependencies]
 tnflow = [
+    "cotengra",
     "sparse",
     "opt-einsum",
     "quimb",
@@ -63,7 +64,7 @@ docs = [
     "breathe",
     "sphinxext-opengraph",
     "sphinx-autodoc-typehints",
-    "qiskit-terra[visualization]",
+    "qiskit[visualization]",
     "graphviz",
 ]
 dev = ["mqt.ddsim[tnflow, coverage, docs]"]
@@ -79,8 +80,8 @@ Discussions = "https://github.com/cda-tum/mqt-ddsim/discussions"
 # Protect the configuration against future changes in scikit-build-core
 minimum-version = "0.6.1"
 
-# Set the target to build
-cmake.targets = ["pyddsim"]
+# Set the wheel install directory
+wheel.install-dir = "mqt/ddsim"
 
 # Set required CMake and Ninja versions
 cmake.minimum-version = "3.19"
@@ -89,9 +90,6 @@ ninja.minimum-version = "1.10"
 # Setuptools-style build caching in a local directory
 build-dir = "build/{wheel_tag}"
 
-# Build stable ABI wheels for CPython 3.12+
-wheel.py-api = "cp312"
-
 # Explicitly set the package directory
 wheel.packages = ["src/mqt"]
 
@@ -118,7 +116,7 @@ sdist.exclude = [
 [tool.scikit-build.cmake.define]
 BUILD_MQT_DDSIM_TESTS = "OFF"
 BUILD_MQT_DDSIM_BINDINGS = "ON"
-ENABLE_IPO = "ON"
+BUILD_MQT_DDSIM_CLI = "OFF"
 
 
 [tool.check-sdist]
@@ -147,6 +145,7 @@ filterwarnings = [
     "ignore:.*qiskit.utils.algorithm_globals.QiskitAlgorithmGlobals*:DeprecationWarning:qiskit",
     "ignore:.*Building a flow controller with keyword arguments is going to be deprecated*:PendingDeprecationWarning:qiskit",
     "ignore:.*qiskit.extensions module is pending deprecation*:PendingDeprecationWarning:qiskit",
+    'ignore:.*datetime\.datetime\.utcfromtimestamp.*:DeprecationWarning:',
 ]
 
 [tool.coverage]
@@ -257,7 +256,6 @@ build = "cp3*"
 skip = "*-musllinux_*"
 archs = "auto64"
 test-command = "python -c \"from mqt import ddsim\""
-test-skip = "cp312-*"  # Qiskit Terra does not support Python 3.12 yet
 build-frontend = "build"
 
 [tool.cibuildwheel.linux]