Modernize CMake Build System and Python Packaging Integration

.github/workflows/pypi.yml

@@ -0,0 +1,69 @@
+name: Publish wheels to PyPI
+
+on:
+  # allows running workflows manually
+  workflow_dispatch:
+
+  release:
+    types: [published]
+
+jobs:
+  main:
+    name: Build wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            arch: manylinux_x86_64
+          - os: macos-13
+            arch: macosx_x86_64
+          - os: macos-14
+            arch: macosx_arm64
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Build wheels
+        uses: pypa/[email protected]
+        env:
+          CIBW_BUILD: "cp*-${{ matrix.arch }}"
+          CIBW_ARCHS_LINUX: "x86_64"
+          CIBW_MANYLINUX_X86_64_IMAGE: quay.io/pypa/manylinux_2_34_x86_64
+          CIBW_ARCHS_MACOS: "native"
+          CIBW_ENVIRONMENT_MACOS: >
+            MACOSX_DEPLOYMENT_TARGET=${{ matrix.os == 'macos-14' && '14.0' || '13.0' }}
+            DYLD_LIBRARY_PATH=/usr/local/opt/gcc/lib/gcc/current/:$DYLD_LIBRARY_PATH
+            FC=gfortran-14
+          CIBW_BUILD_FRONTEND: "build"
+        with:
+          package-dir: .
+          output-dir: wheelhouse
+          config-file: "{package}/pyproject.toml"
+
+      - name: Upload wheels
+        uses: actions/upload-artifact@v4
+        with:
+          name: vmecpp-wheels-${{ matrix.os }}
+          path: ./wheelhouse/*.whl
+
+  publish:
+    name: Publish wheels to PyPI
+    if: github.event_name == 'release'
+    needs: main
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          path: wheelhouse
+
+      - name: Publish package distributions to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1

.gitignore

@@ -1,2 +1,6 @@
-/bin
-/build
+__pycache__
+*.egg-info
+*.egg
+*.pyc
+build
+dist

cmake/GenerateScript.cmake

@@ -0,0 +1,33 @@
+# Function to generate and install a Python script
+# This function creates a Python script with a specified name, writes content to it, 
+# and installs it to a specified location.
+#
+# Arguments:
+#   SCRIPT_NAME - The name of the script to be generated (e.g., 'my_script').
+
+function(generate_and_install_python_script SCRIPT_NAME)
+    if(SKBUILD)
+        # Strip any leading/trailing whitespace from the script name
+        string(STRIP "${SCRIPT_NAME}" CLEAN_SCRIPT_NAME)
+
+        # Define the output path for the generated script using the cleaned name
+        set(GENERATED_SCRIPT "${CMAKE_BINARY_DIR}/scripts/${CLEAN_SCRIPT_NAME}")
+
+        # Generate the script content directly
+        file(WRITE "${GENERATED_SCRIPT}" "#!/usr/bin/env python3\n\n")
+        file(APPEND "${GENERATED_SCRIPT}" "import os\n")
+        file(APPEND "${GENERATED_SCRIPT}" "import sys\n")
+        file(APPEND "${GENERATED_SCRIPT}" "import sysconfig\n\n")
+        file(APPEND "${GENERATED_SCRIPT}" "if __name__ == '__main__':\n")
+        file(APPEND "${GENERATED_SCRIPT}" "    os.execv(\n")
+        file(APPEND "${GENERATED_SCRIPT}" "        os.path.join(sysconfig.get_path('platlib'), '${SKBUILD_PROJECT_NAME}', '${CMAKE_INSTALL_BINDIR}', '${CLEAN_SCRIPT_NAME}'),\n")
+        file(APPEND "${GENERATED_SCRIPT}" "        sys.argv,\n")
+        file(APPEND "${GENERATED_SCRIPT}" "    )\n")
+
+        # Install the generated script
+        install(
+            PROGRAMS "${GENERATED_SCRIPT}"
+            DESTINATION "${SKBUILD_SCRIPTS_DIR}"
+        )
+    endif()
+endfunction()

njoy/__init__.py

@@ -0,0 +1,7 @@
+from importlib.metadata import version, PackageNotFoundError
+from .paths import *
+
+try:
+    __version__ = version('njoy')
+except PackageNotFoundError:
+    __version__ = "unknown"

njoy/paths.py

@@ -0,0 +1,61 @@
+import os
+import sys
+import glob
+import warnings
+from . import __path__
+
+CORE_BASE_PATH = os.path.join(__path__[0], "core")
+
+if not os.path.exists(CORE_BASE_PATH):
+    import sysconfig
+    CORE_BASE_PATH = os.path.join(sysconfig.get_path("platlib"), "njoy", "core")
+    if not os.path.exists(CORE_BASE_PATH):
+        raise ImportError("NJOY is not installed. Please run 'pip install njoy'.")
+    if os.environ.get("NJOY_DEV_MODE", "0") != "1":
+        warnings.warn(
+            "It seems that NJOY is being run from its source directory. "
+            "This setup is not recommended as it may lead to unexpected behavior, "
+            "such as conflicts between source and installed versions. "
+            "Please run your script from outside the NJOY source tree.",
+            RuntimeWarning
+        )
+
+def get_paths(subdir, pattern="*", recursive=False):
+    """
+    Helper function to return paths that match a given pattern within a subdirectory.
+
+    Args:
+        subdir (str): The subdirectory within the 'core' directory.
+        pattern (str): The pattern to match files or directories.
+        recursive (bool): Whether to search recursively in subdirectories.
+
+    Returns:
+        list: A list of matched paths.
+    """
+    search_pattern = os.path.join(CORE_BASE_PATH, subdir, "**", pattern) if recursive else os.path.join(CORE_BASE_PATH, subdir, pattern)
+    return glob.glob(search_pattern, recursive=recursive)
+
+def get_include_path():
+    """Return includes and include path for NJOY headers."""
+    include = get_paths("include", "*", recursive=True)
+    include_path = get_paths("include", "", recursive=False)
+    return include, include_path
+
+def get_core_libraries():
+    """Return libraries and library paths for NJOY."""
+    lib = [lib_file for lib in ["lib", "lib64"] for lib_file in get_paths(lib, "libNJOY*", recursive=True)]
+    lib_path = [lib_file for lib in ["lib", "lib64"] for lib_file in get_paths(lib, "", recursive=False)]
+    return lib, lib_path
+
+def get_extra_libraries():
+    """Return the extra libraries installed by auditwheel or delocate."""
+    libs_path = os.path.join(__path__[0], ".dylibs") if sys.platform == "darwin" else os.path.normpath(os.path.join(__path__[0], "..", "njoy.libs"))
+    return (glob.glob(os.path.join(libs_path, "*")), libs_path) if os.path.exists(libs_path) else ([], [])
+
+# Setup variables
+include, include_path = get_include_path()
+lib, lib_path = get_core_libraries()
+extra_lib, extra_lib_path = get_extra_libraries()
+
+# Export variables for easy access
+__all__ = ["include", "include_path", "lib", "lib_path", "extra_lib", "extra_lib_path"]

pyproject.toml

@@ -0,0 +1,48 @@
+[build-system]
+requires = ["scikit-build-core", "setuptools-scm"]
+build-backend = "scikit_build_core.build"
+
+[project]
+name = "njoy"
+description = "NJOY is a modular code that processes ENDF nuclear data into libraries for applications, with independent modules communicating via files."
+authors = [{ name = "The NJOY Development Team", email = "[email protected]" }]
+license = { file = "LICENSE" }
+readme = "README.md"
+requires-python = ">=3.8"
+dynamic = ["version"]
+
+keywords = [
+    "Nuclear Data",
+    "ENDF",
+    "Nuclear Engineering",
+    "Nuclear Physics",
+    "Monte Carlo",
+    "Neutron Transport",
+]
+
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Intended Audience :: Developers",
+    "Intended Audience :: End Users/Desktop",
+    "Intended Audience :: Science/Research",
+    "License :: OSI Approved :: BSD 3-Clause License",
+    "Natural Language :: English",
+    "Topic :: Scientific/Engineering",
+    "Programming Language :: Fortran",
+    "Programming Language :: Python :: 3",
+]
+
+[project.urls]
+Homepage = "https://www.njoy21.io/NJOY2016/"
+Documentation = "https://www.njoy21.io/NJOY2016/"
+Repository = "https://github.com/njoy/NJOY2016"
+Issues = "https://github.com/njoy/NJOY2016/issues"
+
+[tool.scikit-build]
+build.verbose = true
+logging.level = "INFO"
+wheel.packages = ["njoy"]
+wheel.install-dir = "njoy"
+metadata.version.provider = "scikit_build_core.metadata.setuptools_scm"
+
+[tool.setuptools_scm]