Migration build system to Meson

.github/workflows/build.yml

@@ -22,7 +22,7 @@ jobs:
             core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
             core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           submodules: true
 
@@ -60,118 +60,41 @@ jobs:
   Build-mac:
     runs-on: macos-latest
     steps:
-      - name: Export GitHub Actions cache environment variables
-        uses: actions/github-script@v7
-        with:
-          script: |
-            core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
-            core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
-
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           submodules: true
 
-      - name: Install system-wide build tools
-        shell: bash
-        # Install
-        #   mono: NuGet requires a dotnet runtime
-        #   ninja: Build system
-        #   llvm: Just for clang-tidy. Need to add to path.
-        # Just add clang-tidy to path, not all of LLVM clang.
-        run: |
-          brew install mono ninja llvm
-          ln -s $(brew --prefix llvm)/bin/clang-tidy /usr/local/bin/clang-tidy
-          brew install autoconf autoconf-archive automake libtool
+      - name: Install dependencies
+        run: brew install meson ninja fftw armadillo googletest google-benchmark pybind11
 
-      - name: Setup VCPKG
-        shell: bash
-        run: |
-          cd ${{ github.workspace }}
-          git clone https://github.com/microsoft/vcpkg
-          ${{ github.workspace }}/vcpkg/bootstrap-vcpkg.sh
+      - name: Meson setup
+        run: meson setup builddir --buildtype=release
 
-      - name: Add NuGet sources
-        shell: bash
-        env:
-          gh_packages_secret: ${{ secrets.GH_PACKAGES_TOKEN }}
-        if: ${{ env.gh_packages_secret != '' }}
-        run: |
-          mono `${{ env.VCPKG_EXE }} fetch nuget | tail -n 1` \
-            sources add \
-            -Source "${{ env.FEED_URL }}" \
-            -StorePasswordInClearText \
-            -Name GitHubPackages \
-            -UserName "${{ env.USERNAME }}" \
-            -Password "${{ secrets.GH_PACKAGES_TOKEN }}"
-          mono `${{ env.VCPKG_EXE }} fetch nuget | tail -n 1` \
-            setapikey "${{ secrets.GH_PACKAGES_TOKEN }}" \
-            -Source "${{ env.FEED_URL }}"
+      - name: Build
+        run: meson compile -C builddir
 
-      - name: CMake configure
-        shell: bash
-        run: cmake --preset clang
-
-      - name: CMake build
-        shell: bash
-        run: cmake --build --preset clang-release
-
-      - name: CTest
-        shell: bash
-        run: ctest --output-on-failure --test-dir build/clang/test/
+      - name: Test
+        run: meson test -C builddir --print-errorlogs
 
   Build-linux:
     runs-on: ubuntu-24.04
     steps:
-      - name: Export GitHub Actions cache environment variables
-        uses: actions/github-script@v7
-        with:
-          script: |
-            core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
-            core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
-
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           submodules: true
 
-      - name: Install system dependencies
-        shell: bash
+      - name: Install dependencies
         run: |
           sudo apt-get update
-          sudo apt-get install -y mono-devel ninja-build pkg-config cmake clang clang-tidy
-
-      - name: Setup VCPKG
-        shell: bash
-        run: |
-          cd ${{ github.workspace }}
-          git clone https://github.com/microsoft/vcpkg
-          ${{ github.workspace }}/vcpkg/bootstrap-vcpkg.sh
+          sudo apt-get install -y meson ninja-build pkg-config clang \
+            libfftw3-dev libarmadillo-dev libgtest-dev libbenchmark-dev \
+            pybind11-dev
 
-      - name: Add NuGet sources
-        shell: bash
-        env:
-          gh_packages_secret: ${{ secrets.GH_PACKAGES_TOKEN }}
-        if: ${{ env.gh_packages_secret != '' }}
-        run: |
-          # Use nuget via mono (since mono is not pre-installed on ubuntu, and vcpkg fetches the Windows nuget binary)
-          mono `${{ env.VCPKG_EXE }} fetch nuget | tail -n 1` \
-            sources add \
-            -Source "${{ env.FEED_URL }}" \
-            -StorePasswordInClearText \
-            -Name GitHubPackages \
-            -UserName "${{ env.USERNAME }}" \
-            -Password "${{ secrets.GH_PACKAGES_TOKEN }}"
-          mono `${{ env.VCPKG_EXE }} fetch nuget | tail -n 1` \
-            setapikey "${{ secrets.GH_PACKAGES_TOKEN }}" \
-            -Source "${{ env.FEED_URL }}"
+      - name: Meson setup
+        run: CC=clang CXX=clang++ meson setup builddir --buildtype=release
 
-      - name: CMake configure
-        shell: bash
-        run: cmake --preset clang
-
-      - name: CMake build
-        shell: bash
-        run: cmake --build --preset clang-release
+      - name: Build
+        run: meson compile -C builddir
 
-      - name: CTest
-        shell: bash
-        run: ctest --output-on-failure --test-dir build/clang/test/
+      - name: Test
+        run: meson test -C builddir --print-errorlogs

.gitignore

@@ -13,7 +13,7 @@ __pycache__/
 
 # Distribution / packaging
 .Python
-build/
+build*/
 develop-eggs/
 dist/
 downloads/

.vscode/settings.json

@@ -1 +1,3 @@
-{}
+{
+    "C_Cpp.default.configurationProvider": "mesonbuild.mesonbuild",
+}

benchmark/meson.build

@@ -0,0 +1,9 @@
+benchmark_dep = dependency('benchmark')
+armadillo_dep = dependency('armadillo')
+
+executable('bench_fftconv',
+  'bench_fftconv.cpp',
+  'bench_hilbert.cpp',
+  include_directories : fftconv_inc,
+  dependencies : [fftw3_dep, fftw3f_dep, benchmark_dep, armadillo_dep],
+)

include/fftconv/fftconv.hpp

@@ -8,10 +8,8 @@
 #include <complex>
 #include <fftconv/aligned_vector.hpp>
 #include <fftconv/fftw.hpp>
-#include <memory>
 #include <span>
 #include <type_traits>
-#include <unordered_map>
 
 // NOLINTBEGIN(*-reinterpret-cast, *-const-cast, *-pointer-arithmetic)
 
@@ -386,13 +384,12 @@ struct FFTConvEngine : public fftw::cache_mixin<FFTConvEngine<T, PlannerFlag>> {
 
     const size_t fft_size = buf.real.size();
     const size_t step_size = fft_size - (k.size() - 1);
+    const T fct = static_cast<T>(1. / fft_size);
 
     // forward fft of kernel and save to complex2
     internal::copy_to_padded_buffer<T>(k, buf.real);
     forward.execute_dft_r2c(buf.real_ptr(), buf.cx2_ptr());
 
-    const auto fct = static_cast<T>(1. / fft_size);
-
     if constexpr (Mode == ConvMode::Full) {
       assert(a.size() + k.size() - 1 == out.size());
 
@@ -450,7 +447,7 @@ struct FFTConvEngine : public fftw::cache_mixin<FFTConvEngine<T, PlannerFlag>> {
 //    * Cache fftw_plan
 //    * Reuse buffers (no malloc on second call to the same convolution size)
 // https://en.wikipedia.org/w/index.php?title=Convolution#Fast_convolution_algorithms
-template <Floating T, ConvMode Mode = ConvMode::Same,
+template <Floating T, ConvMode Mode = ConvMode::Full,
           int PlannerFlag = FFTW_ESTIMATE>
 void convolve_fftw(const std::span<const T> input,
                    const std::span<const T> kernel, std::span<T> output) {
@@ -471,7 +468,7 @@ For "Same" mode, output_size == input_size
 2. convolve with kernel using fft of length N.
 3. add blocks together
  */
-template <Floating T, ConvMode Mode = ConvMode::Same,
+template <Floating T, ConvMode Mode = ConvMode::Full,
           int PlannerFlag = FFTW_ESTIMATE>
 void oaconvolve_fftw(std::span<const T> input, std::span<const T> kernel,
                      std::span<T> output) {

include/fftconv/fftw.hpp

@@ -7,8 +7,8 @@ A C++ FFTW wrapper
 #include <complex>
 #include <cstdlib>
 #include <fftw3.h>
-#include <span>
 #include <memory>
+#include <span>
 #include <type_traits>
 #include <unordered_map>
 
@@ -20,7 +20,8 @@ A C++ FFTW wrapper
 #include <arm_neon.h>
 #endif
 
-// NOLINTBEGIN(*-pointer-arithmetic, *-macro-usage, *-const-cast)
+// NOLINTBEGIN(*-pointer-arithmetic, *-macro-usage, *-const-cast,
+// *-math-missing-parenthesis)
 
 namespace fftw {
 
@@ -31,8 +32,10 @@ struct WisdomSetup {
   explicit WisdomSetup(bool threadSafe) {
     static bool callSetup = true;
     if (threadSafe && callSetup) {
+#if defined FFTW_HAVE_THREADS
       fftw_make_planner_thread_safe();
       fftwf_make_planner_thread_safe();
+#endif
       callSetup = false;
     }
     fftw_import_wisdom_from_filename(".fftw_wisdom");
@@ -625,7 +628,7 @@ Helper functions
 out[i] += in[i] * fct
  */
 template <typename T>
-inline void normalize_add(T *out, T *in, size_t len, T fct) {
+inline void normalize_add(T *out, const T *in, size_t len, T fct) {
   for (size_t i = 0; i < len; ++i) {
     out[i] += in[i] * fct;
   }
@@ -637,9 +640,7 @@ out[i] += in[i] * fct
 template <typename T>
 inline void normalize_add(std::span<T> out, std::span<const T> in, T fct) {
   const auto len = std::min(out.size(), in.size());
-  for (size_t i = 0; i < len; ++i) {
-    out[i] += in[i] * fct;
-  }
+  normalize_add<T>(out.data(), in.data(), len, fct);
 }
 
 /**
@@ -925,4 +926,5 @@ void scale_imag_and_magnitude(T const *real, T const *imag, T fct, size_t n,
 
 } // namespace fftw
 
-// NOLINTEND(*-pointer-arithmetic, *-macro-usage, *-const-cast)
+// NOLINTEND(*-pointer-arithmetic, *-macro-usage, *-const-cast,
+// *-math-missing-parenthesis)

include/fftconv/hilbert.hpp

@@ -5,7 +5,8 @@
 #include <fftconv/fftw.hpp>
 #include <span>
 
-// NOLINTBEGIN(*-pointer-arithmetic, *-magic-numbers)
+// NOLINTBEGIN(*-pointer-arithmetic, *-magic-numbers,
+// *-math-missing-parenthesis)
 
 namespace fftconv {
 
@@ -15,19 +16,19 @@ Uses FFTW's r2c transform
 */
 template <fftw::Floating T>
 void hilbert(const std::span<const T> x, const std::span<T> env) {
-  const auto n = x.size();
+  const size_t n = x.size();
   assert(n > 0);
   assert(x.size() == env.size());
 
   fftw::EngineR2C1D<T> &engine = fftw::EngineR2C1D<T>::get(n);
   fftw::R2CBuffer<T> &buf = engine.buf;
 
-  if (isSIMDAligned<64>(x.data())) {
+  if (isSIMDAligned<32>(x.data())) {
     // Avoid a copy
     engine.forward(x.data(), buf.out);
   } else {
     // Copy input to real buffer
-    for (int i = 0; i < n; ++i) {
+    for (size_t i = 0; i < n; ++i) {
       buf.in[i] = x[i];
     }
 
@@ -36,8 +37,8 @@ void hilbert(const std::span<const T> x, const std::span<T> env) {
   }
 
   // Multiply by 1j (skip DC and Nyquist)
-  const auto cx_size = n / 2 + 1;
-  for (auto i = 0; i < cx_size; ++i) {
+  const size_t cx_size = n / 2 + 1;
+  for (size_t i = 0; i < cx_size; ++i) {
     // Skip DC (0 Hz) and Nyquist (n/2 Hz when n is even)
     if (i == 0 || (n % 2 == 0 && i == cx_size - 1)) {
       buf.out[i][0] = 0.0;
@@ -56,7 +57,7 @@ void hilbert(const std::span<const T> x, const std::span<T> env) {
   // Take the abs of the analytic signal
   const T fct = static_cast<T>(1. / n);
 
-  for (auto i = 0; i < n; ++i) {
+  for (size_t i = 0; i < n; ++i) {
     const auto real = x[i];
     const auto imag = buf.in[i] * fct;
     env[i] = std::sqrt(real * real + imag * imag);
@@ -182,4 +183,4 @@ void hilbert(const std::span<const T> x, const std::span<T> env) {
 
 } // namespace fftconv
 
-// NOLINTEND(*-pointer-arithmetic, *-magic-numbers)
+// NOLINTEND(*-pointer-arithmetic, *-magic-numbers, *-math-missing-parenthesis)

meson.build

@@ -0,0 +1,13 @@
+project('fftconv', 'c', 'cpp',
+  version : '0.5.1',
+  default_options : ['cpp_std=c++20', 'warning_level=2'],
+)
+
+fftconv_inc = include_directories('include')
+
+fftw3_dep = dependency('fftw3')
+fftw3f_dep = dependency('fftw3f')
+
+subdir('test')
+subdir('benchmark')
+subdir('py')

py/meson.build

@@ -0,0 +1,18 @@
+py = import('python').find_installation(pure: false)
+pybind11_dep = dependency('pybind11')
+
+py.extension_module(
+  '_pyfftconv',
+  'main.cpp',
+  include_directories: fftconv_inc,
+  dependencies: [fftw3_dep, fftw3f_dep, pybind11_dep],
+  install: true,
+  subdir: 'pyfftconv',
+)
+
+py.install_sources(
+  'pyfftconv/__init__.py',
+  'pyfftconv/__init__.pyi',
+  'pyfftconv/_pyfftconv.pyi',
+  subdir: 'pyfftconv',
+)

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
-requires = ["scikit-build-core>=0.10", "pybind11"]
-build-backend = "scikit_build_core.build"
+requires = ["meson-python", "pybind11"]
+build-backend = "mesonpy"
 
 [project]
 name = "pyfftconv"
@@ -16,20 +16,3 @@ classifiers = [
 
 [project.urls]
 homepage = "https://github.com/kwsp/fftconv"
-
-[tool.scikit-build]
-minimum-version = "build-system.requires"
-logging.level = "INFO"
-
-cmake.version = ">=3.20"
-cmake.args = [
-    "--preset=clang",
-    "-GNinja",        # -GNinja overrides the "Ninja Multi-Config" defined in the preset
-]
-cmake.build-type = "Release"
-cmake.source-dir = "."
-
-build.verbose = true
-build.targets = ["_pyfftconv"]
-
-wheel.packages = ["py/pyfftconv"]