meson: use new python module

This patch makes the tests pass running uninstalled and installed, with
python2 and python3 on linux, windows and osx.

The main gist is to use the new python-module to do the lifting done
by pythondetector, and with that add support for python2 and windows.

gi/overrides/Gst.py

@@ -566,7 +566,7 @@ def TIME_ARGS(time):
                                   time % Gst.SECOND)
 __all__.append('TIME_ARGS')
 
-from . import _gi_gst
+import _gi_gst
 _gi_gst
 
 # maybe more python and less C some day if core turns a bit more introspection

gi/overrides/meson.build

@@ -2,17 +2,18 @@ pysources = ['Gst.py', 'GstPbutils.py']
 install_data(pysources,
     install_dir: pygi_override_dir)
 
-gstpython = shared_library('_gi_gst',
+gstpython = python.extension_module('_gi_gst',
     sources: ['gstmodule.c'],
-    name_prefix: '',
-    name_suffix: py_so_suffix,
     install: true,
     install_dir : pygi_override_dir,
+    include_directories : [configinc],
     dependencies : [gst_dep, python_dep, pygobject_dep])
 
+gi_overrides_build_dir = meson.current_build_dir()
+
 # Workaround to get uninstalled working.
 foreach source: pysources
-    run_command(python3, '-c', 'import os; os.symlink("@0@/@1@", "@2@/@3@")'.format(
+    run_command(python, '-c', 'import os; os.symlink("@0@/@1@", "@2@/@3@")'.format(
         meson.current_source_dir(), source,
-        meson.current_build_dir(), source))
+        gi_overrides_build_dir, source))
 endforeach

meson.build

@@ -11,6 +11,8 @@ gst_version_major = version_arr[0]
 gst_version_minor = version_arr[1]
 api_version = '@0@.0'.format(gst_version_major)
 
+add_project_arguments('-DHAVE_CONFIG_H', language: 'c')
+
 gst_req = '>= @0@.@1@.0'.format(gst_version_major, gst_version_minor)
 
 gst_dep = dependency('gstreamer-1.0', version : gst_req,
@@ -21,32 +23,32 @@ gmodule_dep = dependency('gmodule-2.0')
 pygobject_dep = dependency('pygobject-3.0', fallback: ['pygobject', 'pygobject_dep'], version : '>= 3.8')
 python_dep = dependency('python3')
 
-python3 = import('python3').find_python()
-pythondetector = find_program('scripts/pythondetector')
+pymod = import('python')
+python = pymod.find_installation(get_option('python'))
+python_dep = python.dependency(required : true)
 
-cres = run_command(pythondetector, '--sosuffix')
-if cres.returncode() != 0
-    error('Could not detect python sosuffix' + cres.stdout() + cres.stderr())
+python_abi_flags = python.get_variable('ABIFLAGS', '')
+pylib_loc = python.get_variable('LIBPL', '')
+if host_machine.system() != 'windows'
+    assert(pylib_loc != '', 'Python dynamic library path could not be determined')
 endif
-py_so_suffix = cres.stdout().strip()
+message('python_abi_flags = @0@'.format(python_abi_flags))
+message('pylib_loc = @0@'.format(pylib_loc))
 
-cres = run_command(pythondetector, '--abiflags')
-if cres.returncode() != 0
-    error('Could not detect python abiflags' + cres.stdout() + cres.stderr())
-endif
-python_abi_flags = cres.stdout().strip()
-
-cres = run_command(pythondetector, '--libloc')
-if cres.returncode() != 0
-    error('Could not detect python library location' + cres.stdout() + cres.stderr())
-endif
-pylib_loc = cres.stdout().strip()
-
-assert(pylib_loc != 'None', 'Python dynamic library path could not be determined')
 pygi_override_dir = get_option('pygi-overrides-dir')
 if pygi_override_dir == ''
-    cres = run_command(pythondetector, '--pygi-overridedir',
-            get_option('prefix'))
+    cres = run_command(python, '-c','''
+import os, sys, gi.overrides
+paths = gi.overrides.__path__
+prefix = os.path.abspath(sys.argv[1])
+for path in paths:
+    path = os.path.abspath(path)
+    if os.path.commonprefix([path, prefix]) == prefix:
+        print(path)
+        exit(0)
+exit(1)
+''', get_option('prefix'))
+
     if cres.returncode() != 0
         error('Could not detect PyGObject overrides location' + cres.stdout() + cres.stderr())
     endif
@@ -55,7 +57,7 @@ if pygi_override_dir == ''
         message(cres.stderr())
     endif
 endif
-message('pygobject overrides directory ' + pygi_override_dir)
+message('pygobject overrides directory = @0@'.format(pygi_override_dir))
 
 pylib_suffix = 'so'
 if host_machine.system() == 'windows'
@@ -81,4 +83,4 @@ subdir('gi')
 subdir('plugin')
 subdir('testsuite')
 
-run_command(python3, '-c', 'import shutil; shutil.copy("hooks/pre-commit.hook", ".git/hooks/pre-commit")')
+run_command(python, '-c', 'import shutil; shutil.copy("hooks/pre-commit.hook", ".git/hooks/pre-commit")')

meson_options.txt

@@ -1,2 +1,4 @@
 option('pygi-overrides-dir', type : 'string', value : '',
         description: 'Path to pygobject overrides directory')
+
+option('python', type : 'string', value : 'python3')

plugin/meson.build

@@ -1,6 +1,5 @@
 gst_elements_shared = shared_library('gstpython',
     ['gstpythonplugin.c'],
-    c_args : '-DHAVE_CONFIG_H -DPY_LIB_LOC=@0@'.format(pylib_loc),
     include_directories : [configinc],
     dependencies : [gst_dep, pygobject_dep, gstbase_dep, python_dep, gmodule_dep],
     install : true,

scripts/pythondetector

@@ -1,84 +0,0 @@
-#!/usr/bin/env python3
-import os
-import platform
-import subprocess
-import sys
-
-from distutils import sysconfig
-
-
-try:
-    sys.path.remove(os.path.abspath(os.path.join(os.path.dirname(os.path.realpath(__file__)),
-                                                 '..')))
-except ValueError:
-    pass
-
-def get_python_abiflags():
-    return sysconfig.get_config_var("ABIFLAGS")
-
-def get_python_libloc():
-    # OSX is a pain. Python as shipped by apple installs libpython in /usr/lib
-    # so we hardcode that. Other systems can use --with-libpython-dir to
-    # override this.
-    if platform.system().lower() == 'darwin':
-        return '/usr/lib'
-
-    pylib_loc = sysconfig.get_config_var("LIBPL")
-    pylib_ldlibrary = sysconfig.get_config_var("LDLIBRARY")
-
-    py_sharedlib = os.path.join(pylib_loc, pylib_ldlibrary)
-    if os.path.exists(py_sharedlib):
-        return pylib_loc
-
-    # Workaround for Fedora
-    pylib_loc = sysconfig.get_config_var("LIBDIR")
-    pylib_ldlibrary = sysconfig.get_config_var("LDLIBRARY")
-
-    py_sharedlib = os.path.join(pylib_loc, pylib_ldlibrary)
-    if os.path.exists(py_sharedlib):
-        return pylib_loc
-
-    return "None"
-
-
-if __name__ == "__main__":
-    if len(sys.argv) > 3:
-        print("At most 2 arguments accepted")
-        exit(1)
-
-    if sys.argv[1] == '--abiflags':
-        print(get_python_abiflags())
-    elif sys.argv[1] == '--sosuffix':
-        get = sysconfig.get_config_var
-        suffix = get("EXT_SUFFIX") or get("SO") or ".so"
-        print(suffix[1:])
-    elif sys.argv[1] == '--pygi-overridedir':
-        prefix = sys.argv[2]
-        version = sys.version_info
-
-        # If we are installing in the same prefix as PyGobject
-        # make sure to install in the right place.
-        import gi.overrides
-
-        try:
-            gi.overrides.__path__.remove(os.path.abspath(os.path.join(
-                os.path.dirname(os.path.realpath(__file__)), '..', 'gi')))
-        except ValueError:
-            pass
-        overrides_path = gi.overrides.__path__[0]
-        if os.path.commonprefix([overrides_path, prefix]) == prefix:
-            print(overrides_path)
-            exit(0)
-
-        # Otherwise follow python's way of install site packages inside
-        # the provided prefix
-        if os.name == 'posix':
-            print(os.path.join(
-                prefix, 'lib', 'python%d.%d' % (version.major, version.minor),
-                'site-packages', 'gi', 'overrides'))
-        else:
-            print(os.path.join(
-                prefix, 'Lib', 'Python%d%d' % (version.major, version.minor),
-                'site-packages', 'gi', 'overrides'))
-    elif sys.argv[1] == '--libloc':
-        print(get_python_libloc())

testsuite/meson.build

@@ -1,4 +1,4 @@
-runtests = find_program('runtests.py')
+runtests = files('runtests.py')
 
 tests = [
     ['Test gst', 'test_gst.py'],
@@ -17,22 +17,19 @@ if not meson.is_subproject()
   endif
 endif
 
-runcmd = run_command(python3, '-c', '''with open("@0@/mesonconfig.py", "w") as f:
+runcmd = run_command(python, '-c', '''with open("@0@/mesonconfig.py", "w") as f:
     f.write("path='@1@'")'''.format(
-  meson.current_source_dir(), join_paths(meson.current_build_dir(), '../')))
+  join_paths(meson.current_build_dir()), join_paths(meson.current_build_dir(), '..')))
 
 if runcmd.returncode() != 0
     error('Could not configure testsuite config file.' + runcmd.stderr())
 endif
 
+gi_dir = join_paths(pygi_override_dir, '..', '..')
+
 foreach i: tests
     test_name = i.get(0)
     env = environment()
-    env.set('GST_PLUGIN_PATH_1_0', meson.build_root())
-    env.set('GST_PLUGIN_SYSTEM_PATH_1_0', '')
-    foreach plugindir: pluginsdirs
-      env.append('GST_PLUGIN_PATH_1_0', plugindir)
-    endforeach
-    env.set('GST_REGISTRY', '@0@/@1@.registry'.format(meson.current_build_dir(), i.get(1)))
-    test(test_name, runtests, args: [i.get(1)], env: env)
+    env.prepend('PYTHONPATH', [gi_dir, gi_overrides_build_dir])
+    test(test_name, python, args: [runtests, i.get(1)], env: env)
 endforeach