Move build system to meson-python

.flake8

@@ -41,7 +41,9 @@ per-file-ignores =
     mkl_fft/interfaces/scipy_fft.py: F401
     mkl_fft/interfaces/numpy_fft.py: F401
 
-exclude = _vendored/conv_template.py
+exclude =
+    _vendored/conv_template.py
+    _vendored/process_src_template.py
 
 filename = *.py, *.pyx, *.pxi, *.pxd
 max_line_length = 80

.github/AGENTS.md

@@ -6,7 +6,8 @@ CI/CD workflows and repo automation.
 - `conda-package.yml` — Intel channel conda build/test pipeline
 - `conda-package-cf.yml` — conda-forge-oriented build/test pipeline
 - `build-with-clang.yml` — clang compatibility checks
-- `build_pip.yaml` — wheel build pipeline
+- `build_pip.yml` — editable pip build pipeline
+- `build-with-standard-clang.yml` — standard clang compatibility checks
 - `pre-commit.yml` — lint/format checks
 - `openssf-scorecard.yml` — security scanning
 

.github/copilot-instructions.md

@@ -34,7 +34,7 @@ Higher-precedence file overrides lower-precedence context.
   - `pytest mkl_fft/tests`
 
 ## Source-of-truth files
-- Build/config: `pyproject.toml`, `setup.py`
+- Build/config: `pyproject.toml`, `meson.build`
 - Dependencies: `pyproject.toml`, `conda-recipe/meta.yaml`, `conda-recipe-cf/meta.yaml`
 - CI: `.github/workflows/*.{yml,yaml}`
 - API: `mkl_fft/__init__.py`, `mkl_fft/interfaces/*.py`, `mkl_fft/_pydfti.pyx` (interface wrappers are integration/patch entry points)

.github/workflows/build-with-clang.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         python: ["3.10", "3.11", "3.12", "3.13", "3.14"]
-        numpy_version: ["numpy'>=2'"]
+        numpy_version: ["'numpy>=2'"]
 
     env:
       ONEAPI_ROOT: /opt/intel/oneapi
@@ -37,10 +37,9 @@ jobs:
           sudo add-apt-repository "deb https://apt.repos.intel.com/oneapi all main"
           sudo apt-get update
 
-      - name: Install Intel OneAPI
+      - name: Install Intel oneAPI
         run: |
           sudo apt-get install intel-oneapi-compiler-dpcpp-cpp
-          sudo apt-get install intel-oneapi-tbb
           sudo apt-get install intel-oneapi-mkl-devel
 
       - name: Setup Python
@@ -56,7 +55,7 @@ jobs:
 
       - name: Install mkl_fft dependencies
         run: |
-          pip install cython setuptools">=77"
+          pip install meson-python ninja cython cmake
           pip install ${{ matrix.numpy_version }}
 
       - name: List oneAPI folder content
@@ -73,5 +72,6 @@ jobs:
       - name: Run mkl_fft tests
         run: |
           source ${{ env.ONEAPI_ROOT }}/setvars.sh
-          pip install scipy mkl-service pytest
+          pip install scipy pytest
+          pip install mkl-service --no-deps
           pytest -s -v --pyargs mkl_fft

.github/workflows/build-with-standard-clang.yml

@@ -0,0 +1,64 @@
+name: Build project with standard clang compiler
+
+on:
+  pull_request:
+  push:
+    branches: [master]
+
+permissions: read-all
+
+jobs:
+  build-with-standard-clang:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        python: ["3.10", "3.11", "3.12", "3.13", "3.14"]
+        numpy_version: ["'numpy>=2'"]
+
+    env:
+      COMPILER_ROOT: /usr/bin
+
+    defaults:
+      run:
+        shell: bash -el {0}
+
+    steps:
+      - name: Cancel Previous Runs
+        uses: styfle/cancel-workflow-action@3155a141048f8f89c06b4cdae32e7853e97536bc # 0.13.0
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Install Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang
+
+      - name: Setup Python
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        with:
+          python-version: ${{ matrix.python }}
+          architecture: x64
+
+      - name: Checkout repo
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 0
+
+      - name: Install mkl_fft dependencies
+        run: |
+          pip install meson-python ninja cmake cython mkl-devel
+          pip install ${{ matrix.numpy_version }}
+
+      - name: Build mkl_fft
+        run: |
+          export CC=${{ env.COMPILER_ROOT }}/clang
+          pip install . --no-build-isolation --no-deps --verbose
+
+      - name: Run mkl_fft tests
+        run: |
+          pip install pytest mkl-service scipy
+          # mkl_fft cannot be installed in editable mode, we need
+          # to change directory before importing it and running tests
+          cd ..
+          python -m pytest -sv --pyargs mkl_fft

.github/workflows/build_pip.yaml → .github/workflows/build_pip.yml

@@ -8,11 +8,6 @@ on:
 
 permissions: read-all
 
-env:
-  PACKAGE_NAME: mkl_fft
-  MODULE_NAME: mkl_fft
-  TEST_ENV_NAME: test_mkl_fft
-
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -26,11 +21,6 @@ jobs:
         use_pre: ["", "--pre"]
 
     steps:
-      - name: Install jq
-        shell: bash -l {0}
-        run: |
-          sudo apt-get install jq
-
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           fetch-depth: 0
@@ -48,10 +38,8 @@ jobs:
 
       - name: Build conda package
         run: |
-          pip install --no-cache-dir cython setuptools
+          pip install --no-cache-dir meson-python ninja cmake cython
           pip install --no-cache-dir numpy ${{ matrix.use_pre }}
-          echo "CONDA_PREFFIX is '${CONDA_PREFIX}'"
-          export MKLROOT=${CONDA_PREFIX}
           pip install -e ".[test]" --no-build-isolation --verbose
           pip list
           python -m pytest -v mkl_fft/tests

.github/workflows/conda-package-cf.yml

@@ -76,6 +76,19 @@ jobs:
             "${CHANNELS[@]}" \
             conda-recipe-cf
 
+      - name: Check llvm-openmp linkage
+        run: |
+          # Install built package into a fresh env to inspect linkage
+          conda index /usr/share/miniconda/conda-bld
+          conda create -n check_linkage \
+              -c /usr/share/miniconda/conda-bld -c conda-forge --override-channels \
+              "$PACKAGE_NAME" python=${{ matrix.python }} -y
+          ENV=/usr/share/miniconda/envs/check_linkage
+          echo "--- llvm-openmp symlinks ---"
+          ls -la "$ENV/lib/libgomp"* "$ENV/lib/libiomp5"* "$ENV/lib/libomp.so" || true
+          echo "--- _pydfti omp linkage ---"
+          ldd "$ENV/lib/python${{ matrix.python }}/site-packages/mkl_fft/_pydfti"*.so | grep omp
+
       - name: Upload artifact
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
@@ -210,6 +223,20 @@ jobs:
         run: |
           conda build --no-test --python ${{ matrix.python }} --numpy ${{ matrix.numpy }} -c conda-forge --override-channels conda-recipe-cf
 
+      - name: Check llvm-openmp linkage
+        shell: bash -l {0}
+        run: |
+          CONDA_BLD="$CONDA/conda-bld"
+          conda index "$CONDA_BLD"
+          conda create -n check_linkage \
+              -c "$CONDA_BLD" -c conda-forge --override-channels \
+              "$PACKAGE_NAME" python=${{ matrix.python }} numpy -y
+          ENV="$CONDA/envs/check_linkage"
+          echo "--- llvm-openmp DLLs ---"
+          ls -la "$ENV/Library/bin/libiomp5md.dll" "$ENV/Library/bin/libomp.dll" || true
+          echo "--- import check ---"
+          cd "$TEMP" && "$ENV/python" -c "import mkl_fft; print('import OK')"
+
       - name: Store conda paths as envs
         shell: bash -l {0}
         run: |

.github/workflows/conda-package.yml

@@ -61,6 +61,11 @@ jobs:
       - name: Add conda to system path
         run: echo "$CONDA"/bin >> "$GITHUB_PATH"
 
+      - name: Store conda paths as envs
+        run: |
+          echo "CONDA_BLD=/usr/share/miniconda/conda-bld/linux-64/" >> "$GITHUB_ENV"
+          echo "WHEELS_OUTPUT_FOLDER=$GITHUB_WORKSPACE/" >> "$GITHUB_ENV"
+
       - name: Update conda
         run: |
           conda update -n base --all
@@ -92,7 +97,13 @@ jobs:
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
           name: ${{ env.PACKAGE_NAME }} ${{ runner.os }} Python ${{ matrix.python }}
-          path: /usr/share/miniconda/conda-bld/linux-64/${{ env.PACKAGE_NAME }}-*.conda
+          path: ${{ env.CONDA_BLD }}${{ env.PACKAGE_NAME }}-*.conda
+
+      - name: Upload wheels artifact
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: ${{ env.PACKAGE_NAME }} ${{ runner.os }} Wheels Python ${{ matrix.python }}
+          path: ${{ env.WHEELS_OUTPUT_FOLDER }}${{ env.PACKAGE_NAME }}-*.whl
 
   test_linux:
     needs: build_linux
@@ -239,6 +250,7 @@ jobs:
         shell: bash -l {0}
         run: |
           echo "CONDA_BLD=$CONDA/conda-bld/win-64/" | tr "\\\\" '/' >> "$GITHUB_ENV"
+          echo "WHEELS_OUTPUT_FOLDER=$GITHUB_WORKSPACE\\" >> "$GITHUB_ENV"
 
       - name: Show Conda info
         run: |
@@ -258,6 +270,12 @@ jobs:
           name: ${{ env.PACKAGE_NAME }} ${{ runner.os }} Python ${{ matrix.python }}
           path: ${{ env.CONDA_BLD }}${{ env.PACKAGE_NAME }}-*.conda
 
+      - name: Upload wheels artifact
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: ${{ env.PACKAGE_NAME }} ${{ runner.os }} Wheels Python ${{ matrix.python }}
+          path: ${{ env.WHEELS_OUTPUT_FOLDER }}${{ env.PACKAGE_NAME }}-*.whl
+
   test_windows:
     needs: build_windows
     runs-on:  ${{ matrix.runner }}

AGENTS.md

@@ -16,8 +16,8 @@ It provides accelerated FFT transforms while aiming to preserve upstream API beh
 - **Packaging:** `conda-recipe/`, `conda-recipe-cf/`
 
 ## Build/runtime basics
-- Build system: `pyproject.toml` + `setup.py`
-- Build deps: `cython`, `numpy`, `mkl-devel`
+- Build system: `pyproject.toml` + `meson.build`
+- Build deps: `cython`, `numpy`, `mkl-devel`, `meson-python`, `cmake`, `ninja`
 - Runtime deps: `numpy`, `mkl-service`
 
 ## Development guardrails
@@ -28,7 +28,7 @@ It provides accelerated FFT transforms while aiming to preserve upstream API beh
 - Avoid hardcoding mutable versions/matrices/channels in docs.
 
 ## Where truth lives
-- Build/config: `pyproject.toml`, `setup.py`
+- Build/config: `pyproject.toml`, `meson.build`
 - Dependencies: `pyproject.toml`, `conda-recipe*/meta.yaml`
 - CI/workflows: `.github/workflows/*.{yml,yaml}`
 - Public API: `mkl_fft/__init__.py`, `mkl_fft/interfaces/` (including wrapper/patch adapter modules)

README.md

@@ -1,5 +1,5 @@
 [![Conda package](https://github.com/IntelPython/mkl_fft/actions/workflows/conda-package.yml/badge.svg)](https://github.com/IntelPython/mkl_fft/actions/workflows/conda-package.yml)
-[![Editable build using pip and pre-release NumPy](https://github.com/IntelPython/mkl_fft/actions/workflows/build_pip.yaml/badge.svg)](https://github.com/IntelPython/mkl_fft/actions/workflows/build_pip.yaml)
+[![Editable build using pip and pre-release NumPy](https://github.com/IntelPython/mkl_fft/actions/workflows/build_pip.yml/badge.svg)](https://github.com/IntelPython/mkl_fft/actions/workflows/build_pip.yml)
 [![Conda package with conda-forge channel only](https://github.com/IntelPython/mkl_fft/actions/workflows/conda-package-cf.yml/badge.svg)](https://github.com/IntelPython/mkl_fft/actions/workflows/conda-package-cf.yml)
 [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/IntelPython/mkl_fft/badge)](https://securityscorecards.dev/viewer/?uri=github.com/IntelPython/mkl_fft)
 
@@ -139,25 +139,28 @@ with mkl_fft.mkl_fft():
 ---
 # Building from source
 
-To build `mkl_fft` from sources on Linux with Intel® oneMKL:
-  - create a virtual environment: `python3 -m venv fft_env`
-  - activate the environment: `source fft_env/bin/activate`
-  - install a recent version of oneMKL, if necessary
-  - execute `source /path_to_oneapi/mkl/latest/env/vars.sh`
-  - `git clone https://github.com/IntelPython/mkl_fft.git mkl_fft`
-  - `cd mkl_fft`
-  - `python -m pip install .`
-  - `pip install scipy` (optional: for using `mkl_fft.interface.scipy_fft` module)
-  - `cd ..`
-  - `python -c "import mkl_fft"`
-
-To build `mkl_fft` from sources on Linux with conda follow these steps:
-  - `conda create -n fft_env python=3.12 mkl-devel`
-  - `conda activate fft_env`
-  - `export MKLROOT=$CONDA_PREFIX`
-  - `git clone https://github.com/IntelPython/mkl_fft.git mkl_fft`
-  - `cd mkl_fft`
-  - `python -m pip install .`
-  - `conda install scipy` (optional: for using `mkl_fft.interface.scipy_fft` module)
-  - `cd ..`
-  - `python -c "import mkl_fft"`
+A C compiler, Intel® oneAPI Math Kernel Library (oneMKL), and NumPy are required
+to build `mkl_fft` from source.
+
+Executing
+```sh
+python -m pip install .
+```
+will pull in the required build dependencies, including `mkl` and `numpy`, and build `mkl_fft`.
+
+If you already have `mkl` and `numpy` installed (from your system or a conda environment)
+and want to reuse them instead of pulling fresh copies into an isolated build, first
+install the build dependencies:
+```sh
+pip install meson-python cmake ninja cython numpy mkl-devel
+```
+
+then build against the existing installation with:
+```sh
+python -m pip install --no-build-isolation --no-deps .
+```
+
+Optionally, install `scipy` to use the `mkl_fft.interfaces.scipy_fft` module:
+```sh
+pip install scipy
+```

_vendored/README.md

@@ -1,5 +1,3 @@
 ## Vendored files
 
-File `conv_template.py` is copied from NumPy's numpy/distutils folder, since
-`numpy.distutils` is absent from the installation layout starting with
-Python 3.12
+Files `conv_template.py` and `process_src_template.py` are copied from NumPy's numpy/numpy/_build_utils folder