https://github.com/python/cpython/commit/c931d75831e4176b4876875c01e4b989c89... commit: c931d75831e4176b4876875c01e4b989c8915275 branch: main author: Filipe Laíns 🇵🇸 <lains@riseup.net> committer: FFY00 <filipe.lains@gmail.com> date: 2025-01-29T22:47:20Z summary: GH-127178: improve compatibility in `_sysconfig_vars_(...).json` (#128558) files: M Lib/sysconfig/__init__.py M Lib/sysconfig/__main__.py M Lib/test/test_sysconfig.py diff --git a/Lib/sysconfig/__init__.py b/Lib/sysconfig/__init__.py index 3c3c9796ec3307..69f72452c4069a 100644 --- a/Lib/sysconfig/__init__.py +++ b/Lib/sysconfig/__init__.py @@ -116,8 +116,10 @@ def _getuserbase(): if env_base: return env_base - # Emscripten, iOS, tvOS, VxWorks, WASI, and watchOS have no home directories - if sys.platform in {"emscripten", "ios", "tvos", "vxworks", "wasi", "watchos"}: + # Emscripten, iOS, tvOS, VxWorks, WASI, and watchOS have no home directories. + # Use _PYTHON_HOST_PLATFORM to get the correct platform when cross-compiling. + system_name = os.environ.get('_PYTHON_HOST_PLATFORM', sys.platform).split('-')[0] + if system_name in {"emscripten", "ios", "tvos", "vxworks", "wasi", "watchos"}: return None def joinuser(*args): @@ -342,6 +344,18 @@ def get_makefile_filename(): return os.path.join(get_path('stdlib'), config_dir_name, 'Makefile') +def _import_from_directory(path, name): + if name not in sys.modules: + import importlib.machinery + import importlib.util + + spec = importlib.machinery.PathFinder.find_spec(name, [path]) + module = importlib.util.module_from_spec(spec) + spec.loader.exec_module(module) + sys.modules[name] = module + return sys.modules[name] + + def _get_sysconfigdata_name(): multiarch = getattr(sys.implementation, '_multiarch', '') return os.environ.get( @@ -349,27 +363,34 @@ def _get_sysconfigdata_name(): f'_sysconfigdata_{sys.abiflags}_{sys.platform}_{multiarch}', ) -def _init_posix(vars): - """Initialize the module as appropriate for POSIX systems.""" - # _sysconfigdata is generated at build time, see _generate_posix_vars() + +def _get_sysconfigdata(): + import importlib + name = _get_sysconfigdata_name() + path = os.environ.get('_PYTHON_SYSCONFIGDATA_PATH') + module = _import_from_directory(path, name) if path else importlib.import_module(name) - # For cross builds, the path to the target's sysconfigdata must be specified - # so it can be imported. It cannot be in PYTHONPATH, as foreign modules in - # sys.path can cause crashes when loaded by the host interpreter. - # Rely on truthiness as a valueless env variable is still an empty string. - # See OS X note in _generate_posix_vars re _sysconfigdata. - if (path := os.environ.get('_PYTHON_SYSCONFIGDATA_PATH')): - from importlib.machinery import FileFinder, SourceFileLoader, SOURCE_SUFFIXES - from importlib.util import module_from_spec - spec = FileFinder(path, (SourceFileLoader, SOURCE_SUFFIXES)).find_spec(name) - _temp = module_from_spec(spec) - spec.loader.exec_module(_temp) - else: - _temp = __import__(name, globals(), locals(), ['build_time_vars'], 0) - build_time_vars = _temp.build_time_vars + return module.build_time_vars + + +def _installation_is_relocated(): + """Is the Python installation running from a different prefix than what was targetted when building?""" + if os.name != 'posix': + raise NotImplementedError('sysconfig._installation_is_relocated() is currently only supported on POSIX') + + data = _get_sysconfigdata() + return ( + data['prefix'] != getattr(sys, 'base_prefix', '') + or data['exec_prefix'] != getattr(sys, 'base_exec_prefix', '') + ) + + +def _init_posix(vars): + """Initialize the module as appropriate for POSIX systems.""" # GH-126920: Make sure we don't overwrite any of the keys already set - vars.update(build_time_vars | vars) + vars.update(_get_sysconfigdata() | vars) + def _init_non_posix(vars): """Initialize the module as appropriate for NT""" diff --git a/Lib/sysconfig/__main__.py b/Lib/sysconfig/__main__.py index 10728c709e1811..bc2197cfe79402 100644 --- a/Lib/sysconfig/__main__.py +++ b/Lib/sysconfig/__main__.py @@ -232,10 +232,14 @@ def _generate_posix_vars(): print(f'Written {destfile}') + install_vars = get_config_vars() + # Fix config vars to match the values after install (of the default environment) + install_vars['projectbase'] = install_vars['BINDIR'] + install_vars['srcdir'] = install_vars['LIBPL'] # Write a JSON file with the output of sysconfig.get_config_vars jsonfile = os.path.join(pybuilddir, _get_json_data_name()) with open(jsonfile, 'w') as f: - json.dump(get_config_vars(), f, indent=2) + json.dump(install_vars, f, indent=2) print(f'Written {jsonfile}') diff --git a/Lib/test/test_sysconfig.py b/Lib/test/test_sysconfig.py index 1002d90074599a..3950d8888d4c8c 100644 --- a/Lib/test/test_sysconfig.py +++ b/Lib/test/test_sysconfig.py @@ -650,8 +650,21 @@ def test_sysconfigdata_json(self): system_config_vars = get_config_vars() - # Ignore keys in the check - for key in ('projectbase', 'srcdir'): + ignore_keys = set() + # Keys dependent on Python being run outside the build directrory + if sysconfig.is_python_build(): + ignore_keys |= {'srcdir'} + # Keys dependent on the executable location + if os.path.dirname(sys.executable) != system_config_vars['BINDIR']: + ignore_keys |= {'projectbase'} + # Keys dependent on the environment (different inside virtual environments) + if sys.prefix != sys.base_prefix: + ignore_keys |= {'prefix', 'exec_prefix', 'base', 'platbase'} + # Keys dependent on Python being run from the prefix targetted when building (different on relocatable installs) + if sysconfig._installation_is_relocated(): + ignore_keys |= {'prefix', 'exec_prefix', 'base', 'platbase', 'installed_base', 'installed_platbase'} + + for key in ignore_keys: json_config_vars.pop(key) system_config_vars.pop(key)