setup.py: Build using Meson instead of Autotools by default

This requires mostly dropping support for Python 3.5 and 3.6, both of
which are EOL anyway.

Signed-off-by: Simon McVittie <smcv@collabora.com>

7 files changed, 175 insertions, 89 deletions

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e6ae8ec..4fadeac 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -46,15 +46,6 @@ variables:
       - _autotools/*.log
     when: always
 
-build:python3.5:
-  stage: build
-  image: "debian:stretch-slim"
-  variables:
-    ci_suite: stretch
-    dbus_ci_system_python: python3
-  script: *script
-  artifacts: *artifacts
-
 build:python3.7:
   stage: build
   image: "debian:buster-slim"
diff --git a/Makefile.am b/Makefile.am
index 3b00991..3046439 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -39,6 +39,8 @@ EXTRA_DIST = \
 	examples/unix-fd-service.py \
 	meson.build \
 	meson_options.txt \
+	pyproject.toml \
+	setup.cfg \
 	setup.py \
 	test/TestSuitePythonService.service.in \
 	test/compiled.test.in \
diff --git a/NEWS b/NEWS
index fa7f350..d97d381 100644
--- a/NEWS
+++ b/NEWS
@@ -4,17 +4,27 @@ dbus Python Bindings 1.3.0 (UNRELEASED)
 Dependencies:
 
 • Python 3, version 3.5 or later, is required.
-  A security-supported version (currently 3.6 or later) is recommended.
+  An upstream-supported version (currently 3.7 or later) is strongly
+  recommended, and a future version of dbus-python is likely to require
+  Python 3.7 or later.
   Python 2 is no longer supported.
-• Installing from source code can be done with either Autotools or Meson.
-• Installing from PyPI using pip still relies on Autotools for now.
+
+• Installing from source code using Meson requires Python 3.5 or later
+  and Meson 0.56.2 or later. This is now the recommended build system.
+
+• Installing from source code using Autotools requires Python 3.5 or later.
+  The Autotools build system is likely to be removed in a future version.
+
+• Installing from PyPI using pip or from source code via setup.py
+  requires Python 3.7 or later, Meson 0.60.3 or later, meson-python 0.8.1
+  or later, and their dependencies (ninja, patchelf, setuptools, wheel).
 
 API changes:
 
 • dbus.gobject_service, dbus.types.UTF8String and the utf8_strings
   keyword argument were only usable with Python 2, and therefore have
   been removed, along with the rest of the special cases for Python 2.
-  (dbus-python!115; Simon McVittie)
+  (dbus-python!15; Simon McVittie)
 
 Enhancements:
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..3949d8f
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,50 @@
+# Copyright 2022 Collabora Ltd.
+# SPDX-License-Identifier: MIT
+
+[build-system]
+build-backend = 'mesonpy'
+requires = [
+    'meson-python>=0.8.1',
+    'meson>=0.60.0',
+    'ninja',
+    'patchelf',
+    'setuptools',
+    'wheel',
+]
+
+[project]
+name = 'dbus-python'
+license = { text = 'Expat (MIT/X11)' }
+description = 'Python bindings for libdbus'
+maintainers = [
+    { name = 'The D-Bus maintainers', email = 'dbus@lists.freedesktop.org' },
+]
+requires-python = '>=3.7'
+readme = { file = 'README', content-type = 'text/x-rst' }
+keywords = ['dbus', 'D-Bus']
+classifiers = [
+    'Development Status :: 7 - Inactive',
+    'License :: OSI Approved :: MIT License',
+    'Programming Language :: C',
+    'Programming Language :: Python :: 3',
+    'Programming Language :: Python :: Implementation :: CPython',
+    'Topic :: Software Development :: Object Brokering',
+]
+dynamic = [
+    'version'
+]
+
+[project.optional-dependencies]
+doc = [
+    'sphinx',
+    'sphinx_rtd_theme',
+]
+test = [
+    'tap.py',
+]
+
+[project.urls]
+homepage = 'http://www.freedesktop.org/wiki/Software/DBusBindings/#python'
+download = 'http://dbus.freedesktop.org/releases/dbus-python/'
+source = 'https://gitlab.freedesktop.org/dbus/dbus-python/'
+tracker = 'https://gitlab.freedesktop.org/dbus/dbus-python/-/issues'
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..1c5a0cb
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,40 @@
+# Copyright 2022 Collabora Ltd.
+# SPDX-License-Identifier: MIT
+
+[options]
+python_requires = >=3.7
+setup_requires =
+    meson-python>=0.8.1
+    meson>=0.60.3
+    ninja
+    patchelf
+    setuptools
+    wheel
+zip_safe = False
+
+[metadata]
+name = dbus-python
+license = Expat (MIT/X11)
+description = Python bindings for libdbus
+maintainer = The D-Bus maintainers
+maintainer_email = dbus@lists.freedesktop.org
+long_description = file: README
+keywords =
+    dbus
+    D-Bus
+classifiers =
+    Development Status :: 7 - Inactive
+    License :: OSI Approved :: MIT License
+    Programming Language :: C
+    Programming Language :: Python :: 3
+    Programming Language :: Python :: Implementation :: CPython
+    Topic :: Software Development :: Object Brokering
+url = http://www.freedesktop.org/wiki/Software/DBusBindings/#python
+download_url = http://dbus.freedesktop.org/releases/dbus-python/
+
+[options.extras_require]
+doc =
+    sphinx
+    sphinx_rtd_theme
+test =
+    tap.py
diff --git a/setup.py b/setup.py
index cc604f1..6edf234 100755
--- a/setup.py
+++ b/setup.py
@@ -33,41 +33,83 @@ import os
 import subprocess
 import sys
 
+
+if (
+    os.environ.get('DBUS_PYTHON_USE_AUTOTOOLS', '')
+    or sys.version_info < (3, 7)
+):
+    use_autotools = True
+    setup_requires = ['setuptools', 'wheel']
+else:
+    use_autotools = False
+    setup_requires = ['meson>=0.60.0', 'ninja', 'setuptools', 'wheel']
+
 if os.path.exists('.version'):
     version = open('.version').read().strip()
-else:
+elif use_autotools:
     version = subprocess.check_output(['autoconf', '--trace', 'AC_INIT:$2',
         'configure.ac']).decode('utf-8').strip()
+else:
+    with open('meson.build') as reader:
+        for line in reader:
+            if line.strip().replace(' ', '').startswith('version:'):
+                version = line.split(':', 1)[1]
+                version = version.replace(',', '')
+                version = version.replace('"', '')
+                version = version.replace("'", '')
+                break
+        else:
+            raise AssertionError('Cannot find version in meson.build')
 
 class Build(Distribution().get_command_class('build')):
-    """Dummy version of distutils build which runs an Autotools build system
-    instead.
+    """Dummy version of distutils build which runs an Autotools or Meson
+    build system instead.
     """
 
     def run(self):
         srcdir = os.getcwd()
         builddir = os.path.join(srcdir, self.build_temp)
-        configure = os.path.join(srcdir, 'configure')
         mkpath(builddir)
 
-        if not os.path.exists(configure):
-            configure = os.path.join(srcdir, 'autogen.sh')
+        if use_autotools:
+            configure = os.path.join(srcdir, 'configure')
+
+            if not os.path.exists(configure):
+                configure = os.path.join(srcdir, 'autogen.sh')
 
-        subprocess.check_call([
-                configure,
-                '--disable-maintainer-mode',
-                'PYTHON=' + sys.executable,
-                # Put the documentation, etc. out of the way: we only want
-                # the Python code and extensions
-                '--prefix=' + os.path.join(builddir, 'prefix'),
-            ],
-            cwd=builddir)
-        make_args = [
-            'pythondir=' + os.path.join(srcdir, self.build_lib),
-            'pyexecdir=' + os.path.join(srcdir, self.build_lib),
-        ]
-        subprocess.check_call(['make', '-C', builddir] + make_args)
-        subprocess.check_call(['make', '-C', builddir, 'install'] + make_args)
+            subprocess.check_call([
+                    configure,
+                    '--disable-maintainer-mode',
+                    'PYTHON=' + sys.executable,
+                    # Put the documentation, etc. out of the way: we only want
+                    # the Python code and extensions
+                    '--prefix=' + os.path.join(builddir, 'prefix'),
+                ],
+                cwd=builddir)
+            make_args = [
+                'pythondir=' + os.path.join(srcdir, self.build_lib),
+                'pyexecdir=' + os.path.join(srcdir, self.build_lib),
+            ]
+            subprocess.check_call(['make', '-C', builddir] + make_args)
+            subprocess.check_call(['make', '-C', builddir, 'install'] + make_args)
+        else:
+            subprocess.check_call(
+                [
+                    sys.executable,
+                    '-m', 'mesonbuild.mesonmain',
+                    '--prefix=' + os.path.join(builddir, 'prefix'),
+                    '-Ddoc=false',
+                    '-Dinstalled_tests=false',
+                    '-Dpython=' + sys.executable,
+                    '-Dpython.platlibdir=' + os.path.join(srcdir, self.build_lib),
+                    '-Dpython.purelibdir=' + os.path.join(srcdir, self.build_lib),
+                    '-Dtests=false',
+                    srcdir,
+                    builddir,
+                ]
+            )
+            subprocess.check_call(['meson', 'compile', '-C', builddir])
+            subprocess.check_call(['meson', 'install', '-C', builddir])
 
 class BuildExt(Distribution().get_command_class('build_ext')):
     def run(self):
@@ -85,27 +127,13 @@ dbus_glib_bindings = Extension('_dbus_glib_bindings',
 setup(
     name='dbus-python',
     version=version,
-    description='Python bindings for libdbus',
-    long_description=open('README').read(),
-    maintainer='The D-Bus maintainers',
-    maintainer_email='dbus@lists.freedesktop.org',
-    download_url='http://dbus.freedesktop.org/releases/dbus-python/',
-    url='http://www.freedesktop.org/wiki/Software/DBusBindings/#python',
     packages=['dbus'],
     ext_modules=[dbus_bindings, dbus_glib_bindings],
-    license='Expat (MIT/X11)',
-    classifiers=[
-        'Development Status :: 7 - Inactive',
-        'License :: OSI Approved :: MIT License',
-        'Programming Language :: C',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: Implementation :: CPython',
-        'Topic :: Software Development :: Object Brokering',
-    ],
     cmdclass={
         'build': Build,
         'build_py': BuildPy,
         'build_ext': BuildExt,
     },
+    setup_requires=setup_requires,
     tests_require=['tap.py'],
 )
diff --git a/tools/ci-install.sh b/tools/ci-install.sh
index 93c7c4d..ce9864b 100755
--- a/tools/ci-install.sh
+++ b/tools/ci-install.sh
@@ -63,8 +63,6 @@ else
 fi
 
 have_system_meson=
-have_system_sphinx=
-have_system_tappy=
 
 if [ -n "$ci_docker" ]; then
     sed \
@@ -131,21 +129,10 @@ case "$ci_distro" in
                 python3-gi${dbus_ci_system_python_module_suffix} \
                 python3-pip \
                 python3-setuptools \
+                python3-sphinx \
+                python3-sphinx-rtd-theme \
                 python3-tap \
                 ${NULL}
-
-            case "$ci_suite" in
-                (stretch|bionic)
-                    ;;
-
-                (*)
-                    $sudo apt-get -qq -y install \
-                        python3-sphinx \
-                        python3-sphinx-rtd-theme \
-                        ${NULL}
-                    have_system_sphinx=yes
-                    ;;
-            esac
         fi
 
         if [ "$ci_in_docker" = yes ]; then
@@ -157,7 +144,7 @@ case "$ci_distro" in
         fi
 
         case "$ci_suite" in
-            (stretch|bionic|buster|focal|bullseye)
+            (buster|focal|bullseye)
                 $sudo apt-get -qq -y install dbus
                 ;;
 
@@ -167,7 +154,7 @@ case "$ci_distro" in
         esac
 
         case "$ci_suite" in
-            (stretch|bionic|buster|focal)
+            (buster|focal)
                 ;;
 
             (*)
@@ -186,31 +173,9 @@ esac
 if [ -n "$have_system_meson" ]; then
     :
 elif [ -n "${dbus_ci_system_python-}" ]; then
-    case "$ci_suite" in
-        (stretch|xenial|bionic)
-            # 0.56.2 is the last version that supported Python 3.5
-            runuser -u user -- "$dbus_ci_system_python" -m pip install --user meson==0.56.2 ninja
-            ;;
-        (*)
-            runuser -u user -- "$dbus_ci_system_python" -m pip install --user meson ninja
-            ;;
-    esac
+    runuser -u user -- "$dbus_ci_system_python" -m pip install --user meson ninja
 else
     runuser -u user -- pip install meson ninja
 fi
 
-if [ -n "$have_system_sphinx" ]; then
-    :
-elif [ -n "${dbus_ci_system_python-}" ]; then
-    runuser -u user -- "$dbus_ci_system_python" -m pip install --user \
-        sphinx \
-        sphinx_rtd_theme \
-        ${NULL}
-else
-    runuser -u user -- pip install \
-        sphinx \
-        sphinx_rtd_theme \
-        ${NULL}
-fi
-
 # vim:set sw=4 sts=4 et: