Move from Pybind11 to nanobind

.github/workflows/ci-arch.yml

@@ -3,6 +3,8 @@ name: CI - ArchLinux
 on:
   push:
   pull_request:
+    paths-ignore:
+      - CHANGELOG.md
 
 jobs:
   build-with-arch:
@@ -14,7 +16,7 @@ jobs:
 
     - uses: actions/checkout@v4
       with:
-        submodules: true
+        submodules: recursive
 
     - run: cmake -B build -S . -DBUILD_PYTHON_INTERFACE=ON
     - run: cmake --build build

.github/workflows/ci-linux-osx-win-conda.yml

@@ -3,6 +3,8 @@ name: CI - Linux/OSX/Windows - Conda
 on:
   push:
   pull_request:
+    paths-ignore:
+      - CHANGELOG.md
 
 jobs:
   build-with-conda:
@@ -29,10 +31,6 @@ jobs:
             compiler: clang-cl
           - name: windows-latest
             os: windows-latest
-          - name: macos-latest
-            os: macos-latest
-            build_type: Release
-            cxx_std: 14
           - name: macos-latest
             os: macos-latest
             build_type: Debug
@@ -55,7 +53,9 @@ jobs:
             continue_on_error: false
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
 
     - uses: conda-incubator/setup-miniconda@v2
       if: matrix.os != 'macos-14'
@@ -80,7 +80,7 @@ jobs:
         # Workaround for https://github.com/conda-incubator/setup-miniconda/issues/186
         conda config --remove channels defaults
         # Compilation related dependencies
-        mamba install cmake compilers make pkg-config doxygen ninja graphviz
+        mamba install cmake compilers make pkg-config doxygen ninja graphviz typing_extensions
         # Main dependencies
         mamba install eigen simde
         # Test dependencies

.github/workflows/ci-linux-ros.yml

@@ -1,5 +1,9 @@
 name: CI - Linux - ROS
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+    paths-ignore:
+      - CHANGELOG.md
 
 jobs:
   CI:

.github/workflows/gh-pages.yml

@@ -8,7 +8,9 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
 
       - uses: conda-incubator/setup-miniconda@v2
         with:

.github/workflows/release-linux.yml

@@ -2,6 +2,8 @@ name: Release on PyPI [Linux]
 
 on:
   pull_request:
+    paths-ignore:
+      - CHANGELOG.md
   release:
     types:
       - published
@@ -33,9 +35,9 @@ jobs:
             build: "cp312-manylinux*"
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
-          submodules: 'true'
+          submodules: recursive
       - uses: actions/setup-python@v4
         with:
           python-version: "3.10"

.github/workflows/release-osx-win.yml

@@ -2,6 +2,8 @@ name: Release on PyPI [Windows, Mac]
 
 on:
   pull_request:
+    paths-ignore:
+      - CHANGELOG.md
   release:
     types:
       - published
@@ -21,7 +23,7 @@ jobs:
             toolset: v143
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
 
@@ -57,7 +59,7 @@ jobs:
         run: |
           # Workaround for https://github.com/conda-incubator/setup-miniconda/issues/186
           conda config --remove channels defaults
-          mamba install doxygen graphviz eigen simde cmake compilers
+          mamba install doxygen graphviz eigen simde cmake compilers typing_extensions
 
       - name: Print environment [Conda]
         if: contains(matrix.os, 'macos') || contains(matrix.os, 'windows')

.gitmodules

@@ -1,6 +1,6 @@
-[submodule "external/pybind11"]
-	path = bindings/python/external/pybind11
-	url = https://github.com/pybind/pybind11
+[submodule "bindings/python/external/nanobind"]
+	path = bindings/python/external/nanobind
+	url = https://github.com/wjakob/nanobind
 [submodule "cmake-module"]
 	path = cmake-module
 	url = https://github.com/jrl-umi3218/jrl-cmakemodules.git

CHANGELOG.md

@@ -6,15 +6,23 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
 
+### Added
+
+* Stub files for Python bindings, using [nanobind's native support](https://nanobind.readthedocs.io/en/latest/typing.html#stub-generation) ([#340](https://github.com/Simple-Robotics/proxsuite/pull/340))
+
+### Changed
+
+* Change Python bindings to use nanobind instead of pybind11 ([#340](https://github.com/Simple-Robotics/proxsuite/pull/340))
+
 ## [0.6.7] - 2024-08-27
 
 ### Added
 * Fix mu update function for PrimalLDLT backend ([#349](https://github.com/Simple-Robotics/proxsuite/pull/349))
 * Allow use of installed pybind11, cereal and jrl-cmakemodules via cmake
 * Add compatibility with jrl-cmakemodules workspace ([#339](https://github.com/Simple-Robotics/proxsuite/pull/339))
-* Specifically mention that timings are in microseconds ([#340](https://github.com/Simple-Robotics/proxsuite/pull/340))
-* Fix cereal include directory in cmake ([#340](https://github.com/Simple-Robotics/proxsuite/pull/340))
-* Extend doc with hint for conda installation from source ([#340](https://github.com/Simple-Robotics/proxsuite/pull/340))
+* Specifically mention that timings are in microseconds ([#342](https://github.com/Simple-Robotics/proxsuite/pull/342))
+* Fix cereal include directory in cmake ([#342](https://github.com/Simple-Robotics/proxsuite/pull/342))
+* Extend doc with hint for conda installation from source ([#342](https://github.com/Simple-Robotics/proxsuite/pull/342))
 
 ### Fixed
 * Fix inequality constraints return in QPLayer ([#343](https://github.com/Simple-Robotics/proxsuite/pull/343))

bindings/python/CMakeLists.txt

@@ -1,11 +1,18 @@
 if(UNIX)
-  set(PYTHON_COMPONENTS Development.Module)
+  set(PYTHON_COMPONENTS Interpreter Development.Module)
 endif()
 
 include(${JRL_CMAKE_MODULES}/python.cmake)
 include(${JRL_CMAKE_MODULES}/python-helpers.cmake)
 
-findpython(REQUIRED Development.Module)
+option(GENERATE_PYTHON_STUBS "Generate Python stubs" OFF)
+
+findpython(REQUIRED)
+set(Python_INCLUDE_DIRS ${Python3_INCLUDE_DIRS})
+# Nanobind expects these targets instead of Python3::*
+# https://github.com/jrl-umi3218/jrl-cmakemodules/issues/708
+add_library(Python::Module ALIAS Python3::Module)
+add_executable(Python::Interpreter ALIAS Python3::Interpreter)
 
 if(IS_ABSOLUTE ${PYTHON_SITELIB})
   set(${PYWRAP}_INSTALL_DIR ${PYTHON_SITELIB}/${PROJECT_NAME})
@@ -14,11 +21,21 @@ else()
       ${CMAKE_INSTALL_PREFIX}/${PYTHON_SITELIB}/${PROJECT_NAME})
 endif()
 
-find_package(pybind11 CONFIG)
-if(NOT pybind11_FOUND)
-  file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/external/pybind11)
-  add_subdirectory(external/pybind11
-                   ${CMAKE_CURRENT_BINARY_DIR}/external/pybind11)
+cmake_policy(PUSH)
+cmake_policy(SET CMP0074 NEW)
+# Detect the installed nanobind package and import it into CMake
+execute_process(
+  COMMAND "${Python_EXECUTABLE}" -m nanobind --cmake_dir
+  OUTPUT_STRIP_TRAILING_WHITESPACE
+  OUTPUT_VARIABLE nanobind_ROOT)
+find_package(nanobind CONFIG)
+cmake_policy(POP)
+if(NOT nanobind_FOUND)
+  file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/external/nanobind)
+  add_subdirectory(external/nanobind
+                   ${CMAKE_CURRENT_BINARY_DIR}/external/nanobind)
+else()
+  message(STATUS "Found installed nanobind.")
 endif()
 
 add_custom_target(${PROJECT_NAME}_python)
@@ -29,14 +46,12 @@ file(GLOB_RECURSE PYWRAP_SOURCES ${CMAKE_CURRENT_LIST_DIR}/src/*.cpp)
 
 # Add simd feature detectors for current intel CPU
 if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "(x86)|(X86)|(amd64)|(AMD64)")
-  python3_add_library(instructionset MODULE helpers/instruction-set.cpp)
+  nanobind_add_module(instructionset helpers/instruction-set.cpp)
   add_dependencies(${PROJECT_NAME}_python instructionset)
-  target_link_libraries(instructionset PRIVATE proxsuite pybind11::module)
+  target_link_libraries(instructionset PRIVATE proxsuite)
   set_target_properties(
     instructionset
     PROPERTIES OUTPUT_NAME instructionset
-               PREFIX ""
-               SUFFIX ${PYTHON_EXT_SUFFIX}
                LIBRARY_OUTPUT_DIRECTORY
                "${PROJECT_BINARY_DIR}/bindings/python/${PROJECT_NAME}"
                LIBRARY_OUTPUT_DIRECTORY_RELEASE
@@ -58,6 +73,20 @@ if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "(x86)|(X86)|(amd64)|(AMD64)")
     TARGETS instructionset
     EXPORT ${TARGETS_EXPORT_NAME}
     DESTINATION ${${PYWRAP}_INSTALL_DIR})
+  if(GENERATE_PYTHON_STUBS)
+    nanobind_add_stub(
+      instructionset_stub
+      MODULE
+      instructionset
+      OUTPUT
+      instructionset.pyi
+      PYTHON_PATH
+      $<TARGET_FILE_DIR:instructionset>
+      DEPENDS
+      instructionset)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/instructionset.pyi
+            DESTINATION ${${PYWRAP}_INSTALL_DIR})
+  endif()
 endif()
 
 function(list_filter list regular_expression dest_list)
@@ -72,12 +101,12 @@ function(list_filter list regular_expression dest_list)
 endfunction(list_filter)
 
 function(CREATE_PYTHON_TARGET target_name COMPILE_OPTIONS dependencies)
-  python3_add_library(${target_name} MODULE ${PYWRAP_SOURCES} ${PYWRAP_HEADERS})
+  nanobind_add_module(${target_name} ${PYWRAP_SOURCES} ${PYWRAP_HEADERS})
   add_dependencies(${PROJECT_NAME}_python ${target_name})
 
-  target_link_libraries(${target_name} PUBLIC ${dependencies} pybind11::module)
+  target_link_libraries(${target_name} PUBLIC ${dependencies})
   target_compile_options(${target_name} PRIVATE ${COMPILE_OPTIONS})
-  target_link_libraries(${target_name} PRIVATE proxsuite pybind11::module)
+  target_link_libraries(${target_name} PRIVATE proxsuite)
   target_compile_definitions(${target_name}
                              PRIVATE PYTHON_MODULE_NAME=${target_name})
 
@@ -104,8 +133,6 @@ function(CREATE_PYTHON_TARGET target_name COMPILE_OPTIONS dependencies)
   set_target_properties(
     ${target_name}
     PROPERTIES OUTPUT_NAME ${target_name}
-               PREFIX ""
-               SUFFIX ${PYTHON_EXT_SUFFIX}
                LIBRARY_OUTPUT_DIRECTORY
                "${PROJECT_BINARY_DIR}/bindings/python/${PROJECT_NAME}"
                LIBRARY_OUTPUT_DIRECTORY_RELEASE
@@ -126,6 +153,20 @@ function(CREATE_PYTHON_TARGET target_name COMPILE_OPTIONS dependencies)
   endif()
 
   install(TARGETS ${target_name} DESTINATION ${${PYWRAP}_INSTALL_DIR})
+  if(GENERATE_PYTHON_STUBS)
+    nanobind_add_stub(
+      ${target_name}_stub
+      MODULE
+      ${target_name}
+      OUTPUT
+      ${target_name}.pyi
+      PYTHON_PATH
+      $<TARGET_FILE_DIR:${target_name}>
+      DEPENDS
+      ${target_name})
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${target_name}.pyi
+            DESTINATION ${${PYWRAP}_INSTALL_DIR})
+  endif()
 endfunction()
 
 if(CMAKE_CXX_COMPILER_ID MATCHES MSVC)

bindings/python/helpers/instruction-set.cpp

@@ -1,16 +1,17 @@
 //
-// Copyright (c) 2022 INRIA
+// Copyright (c) 2022-2024 INRIA
 //
 
-#include <pybind11/pybind11.h>
+#include <nanobind/nanobind.h>
+#include <nanobind/stl/string.h>
 
 #include <proxsuite/helpers/instruction-set.hpp>
 
 namespace proxsuite {
 namespace helpers {
 namespace python {
 
-PYBIND11_MODULE(instructionset, m)
+NB_MODULE(instructionset, m)
 {
   m.doc() = R"pbdoc(
         CPU info library