From 91365356bdcc7aa2525d871c12f35320a805a37a Mon Sep 17 00:00:00 2001 From: William Vinnicombe Date: Thu, 26 Oct 2023 13:50:38 +0100 Subject: [PATCH] py: libcamera: Improve python binding installation The existing meson.build file installs the bindings to a manually constructed directory that is not included in the Python path in most distributions. For instance, on a Debian 12 system, the modules is intalled in /usr/lib/x86_64-linux-gnu/python3.11/site-packages/, while the Python interpreter looks for site packages in /usr/lib/python3/dist-packages/. It also always builds the bindings using the system Python, as it searches for the Python library using the standard dependency() function. This prevents build the Python bindings for a different interpreter version without changing the system default interpreter. Modify the build process to use the meson python module to build the Python bindings targets, so it installs them to the correct directories for Python. This also allows specifying a different target Python interpreter through the '[binaries]' section of a meson native file. The behaviour is not changed for cross-compilation, as the meson python module has known issues in that case. Signed-off-by: William Vinnicombe Co-developed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart Reviewed-by: Tomi Valkeinen --- src/py/libcamera/meson.build | 41 ++++++++++++++++++++++++------------ src/py/meson.build | 13 +++++++++++- test/py/meson.build | 3 --- 3 files changed, 40 insertions(+), 17 deletions(-) diff --git a/src/py/libcamera/meson.build b/src/py/libcamera/meson.build index 33ab6579..fe22ffd2 100644 --- a/src/py/libcamera/meson.build +++ b/src/py/libcamera/meson.build @@ -57,16 +57,35 @@ pycamera_args = [ '-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT', ] -destdir = get_option('libdir') / ('python' + py3_dep.version()) / 'site-packages' / 'libcamera' +if meson.is_cross_build() + # Meson doesn't correctly support cross-compilation through the python + # module. There's work in progress to fix this, based on PEP 739 + # (https://github.com/mesonbuild/meson/pull/14657). While waiting for this + # to become available, work around the issue by using shared_module(). + destdir = get_option('libdir') / ('python' + py3_dep.version()) / 'site-packages' / 'libcamera' -pycamera = shared_module('_libcamera', - pycamera_sources, - install : true, - install_dir : destdir, - install_tag : 'python-runtime', - name_prefix : '', - dependencies : pycamera_deps, - cpp_args : pycamera_args) + pycamera = shared_module('_libcamera', + pycamera_sources, + install : true, + install_dir : destdir, + install_tag : 'python-runtime', + name_prefix : '', + dependencies : pycamera_deps, + cpp_args : pycamera_args) + install_data(['__init__.py'], + install_dir : destdir, + install_tag : 'python-runtime') +else + pycamera = py3.extension_module('_libcamera', + pycamera_sources, + install : true, + subdir : 'libcamera', + dependencies : pycamera_deps, + cpp_args : pycamera_args) + py3.install_sources(['__init__.py'], + subdir : 'libcamera', + pure : false) +endif # Create symlinks from the build dir to the source dir so that we can use the # Python module directly from the build dir. @@ -79,10 +98,6 @@ run_command('ln', '-fsrT', meson.current_source_dir() / 'utils', meson.current_build_dir() / 'utils', check : true) -install_data(['__init__.py'], - install_dir : destdir, - install_tag : 'python-runtime') - # \todo Generate stubs when building. See https://peps.python.org/pep-0484/#stub-files # Note: Depends on pybind11-stubgen. To generate pylibcamera stubs: # $ PYTHONPATH=build/src/py pybind11-stubgen --no-setup-py -o build/src/py libcamera diff --git a/src/py/meson.build b/src/py/meson.build index 92280697..24102f83 100644 --- a/src/py/meson.build +++ b/src/py/meson.build @@ -1,6 +1,17 @@ # SPDX-License-Identifier: CC0-1.0 -py3_dep = dependency('python3', required : get_option('pycamera')) +if meson.is_cross_build() + py3_dep = dependency('python3', required : get_option('pycamera')) +else + py3 = import('python').find_installation('python3', required : get_option('pycamera')) + if not py3.found() + pycamera_enabled = false + subdir_done() + endif + + py3_dep = py3.dependency(required : get_option('pycamera')) +endif + pybind11_dep = dependency('pybind11', required : get_option('pycamera')) pycamera_enabled = py3_dep.found() and pybind11_dep.found() diff --git a/test/py/meson.build b/test/py/meson.build index b922e857..d014aac4 100644 --- a/test/py/meson.build +++ b/test/py/meson.build @@ -15,9 +15,6 @@ endif py_env = environment() -pymod = import('python') -py3 = pymod.find_installation('python3') - pypathdir = meson.project_build_root() / 'src' / 'py' py_env.append('PYTHONPATH', pypathdir)