add setuptools_dso.runtime

.gitignore

@@ -9,4 +9,4 @@ build/
 /env/
 *.egg-info/
 
-*_dso.py
+*_dsoinfo.py

example/setup.py

@@ -28,6 +28,8 @@ setup(
     # setup/build time dependencies listed in pyproject.toml
     # cf. PEP 518
     #setup_requires = ['setuptools_dso'],
+    # also need at runtime for DSO filename lookup since demo uses ctypes
+    install_requires = ['setuptools_dso'],
     packages=['dsodemo', 'dsodemo.ext', 'dsodemo.lib'],
     package_dir={'': 'src'},
     ext_modules = [ext],

example/src/dsodemo/cli.py

@@ -3,14 +3,15 @@ from __future__ import print_function
 
 import ctypes
 
+from setuptools_dso import find_dso
+
 from .ext import dtest
-from .lib import demo_dsoinfo
 
 def main():
     print(dtest.foo())
     print(dtest.bar())
     # ctypes.RTLD_GLOBAL ensures we don't load a second instance.
-    demolib = ctypes.CDLL(demo_dsoinfo.sofilename, ctypes.RTLD_GLOBAL)
+    demolib = ctypes.CDLL(find_dso('dsodemo.lib.demo', so=True), ctypes.RTLD_GLOBAL)
     myvar = ctypes.c_int.in_dll(demolib, 'myvar')
     dtest.check_myvar(ctypes.addressof(myvar))
 

example/src/dsodemo/ext/__init__.py

-# import calls os.add_dll_directory() on windows
-from ..lib import demo_dsoinfo
+from setuptools_dso import dylink_prepare_dso
+dylink_prepare_dso('..lib.demo')

src/setuptools_dso/__init__.py

@@ -4,6 +4,7 @@ from __future__ import print_function
 import os
 from setuptools import setup as _setup
 from .dsocmd import DSO, Extension, build_dso, build_ext, bdist_egg
+from .runtime import dylink_prepare_dso, find_dso
 
 from setuptools.command.install import install
 
@@ -14,6 +15,8 @@ __all__ = (
     'build_ext',
     'bdist_egg',
     'setup',
+    'dylink_prepare_dso',
+    'find_dso',
 )
 
 def setup(**kws):

src/setuptools_dso/dsocmd.py

@@ -413,34 +413,20 @@ class build_dso(dso2libmixin, Command):
                     textwrap.dedent(
                         """
                     # generated by setuptools_dso
-                    import sys, os
+                    import os
 
-                    # on windows, extend DLL search path to include
-                    # the directory containing this file
-                    def fixpath():
-                        libdir = os.path.dirname(__file__)
-
-                        if hasattr(os, 'add_dll_directory'): # py >= 3.8
-                            os.add_dll_directory(libdir)
-
-                        elif sys.platform == "win32":
-                            path = os.environ.get('PATH', '').split(os.pathsep)
-                            path.append(libdir)
-                            os.environ['PATH'] = os.pathsep.join(path)
-
-                    fixpath()
-                    del fixpath
-
-                    dsoname = {dsoname!r}
+                    dsoname = {dso.name!r}
                     libname = {libname!r}
                     soname = {soname!r}
+                    depends = {dso.dsos!r}
                     dir = os.path.dirname(__file__)
                     filename = os.path.join(dir, libname)
                     sofilename = os.path.join(dir, soname)
                     del dir
+                    del os
                     __all__ = ("dsoname", "libname", "soname", "filename", "sofilename")
                     """
-                    ).format(dsoname=dso.name,
+                    ).format(dso=dso,
                              libname=self._name2libname(dso),
                              soname=self._name2libname(dso, so=True))
                 )

src/setuptools_dso/runtime.py

+"""
+Tools for interacting with packages containing DSOs w/ dsoinfo modules
+as built with setuptools_dso >= 2 
+"""
+
+from __future__ import print_function
+
+import os
+import sys
+import logging
+import inspect
+from importlib import import_module
+from collections import OrderedDict
+
+__all__ = (
+    'dylink_prepare_dso',
+    'find_dso',
+    'import_dsoinfo',
+)
+
+_log = logging.getLogger(__name__)
+
+# shadow DSO runtime search path to avoid duplication.
+# Only effective on windows.
+_dso_dirs = set()
+
+def add_dso_directory(path):
+    path = os.path.normpath(path)
+
+    # strictly speaking, only needed on windows.
+    # we enforce on all targets for consistency.
+    if not os.path.isabs(path):
+        raise ValueError('DSO search pathes must be absolute: {0!r}'.format(path))
+
+    elif path in _dso_dirs:
+        return
+
+    elif hasattr(os, 'add_dll_directory'): # py >= 3.8
+        os.add_dll_directory(path)
+
+    elif sys.platform == "win32":
+        paths = os.environ.get('PATH', '').split(os.pathsep)
+        paths.append(path)
+        os.environ['PATH'] = os.pathsep.join(paths)
+
+    _log.debug('Extend DSO search path to {0!r}'.format(path))
+    _dso_dirs.add(path)
+
+def _dso2info(dso):
+    """Return mangled name of DSO info module.
+    
+    eg. 'my.pkg.libs.adso' -> 'my.pkg.libs.adso_dsoinfo'
+    """
+    parts = dso.split('.')
+    parts[-1] = '{}_dsoinfo'.format(parts[-1])
+    return '.'.join(parts)
+
+def _auto_pkg():
+    # look 2 frames down in the call stack
+    caller_frame = inspect.stack()[2][0]
+    caller_mod = inspect.getmodule(caller_frame)
+    return caller_mod.__name__
+
+def import_dsoinfo(dso, package=None):
+    """Import and return info module for the named DSO
+
+    :param str dso: DSO name string (eg. 'my.pkg.libs.adso').
+    :param str package: Package name to resolve relative imports.  cf. importlib.import_module
+    :returns: Info module
+    """
+    if package is None:
+        package = _auto_pkg()
+    return import_module(_dso2info(dso), package=package)
+
+def dylink_prepare_dso(dso, package=None):
+    """Take steps necessary to allow the named DSO to be loaded implicitly.
+
+    eg. On Windows, call `os.add_dll_directory()` as neeeded.
+
+    :param str dso: DSO name string (eg. 'my.pkg.libs.adso').
+    :param str package: Package name to resolve relative imports.  cf. importlib.import_module
+    :returns: Info module for the named DSO
+    """
+    if package is None:
+        package = _auto_pkg()
+    todo, found = [dso], OrderedDict()
+
+    # recursively walk dependencies
+    while todo:
+        working = todo.pop(0)
+        info = import_dsoinfo(working, package=package)
+        found[working] = info
+        # libdir must be absolute, but __file__ may be relative if imported via $PWD
+        libdir = os.path.join(os.getcwd(), os.path.dirname(info.__file__))
+        add_dso_directory(libdir)
+        todo.extend([t for t in info.depends if t not in found])
+
+    return next(iter(found.values())) # first value
+
+def find_dso(dso, package=None, so=True):
+    """Lookup DSO file name.  eg. for use with ctypes
+
+    :param str dso: DSO name string (eg. 'my.pkg.libs.adso').
+    :param str package: Package name to resolve relative imports.  cf. importlib.import_module
+    :param bool so: When True (default) return SO qualified name.
+                    eg. "libblah.so.0" vs. "libblah.so".
+                    No effect on Windows.
+    :returns: Absolute path string of DSO file.
+
+    eg.
+
+    >>> fname = setuptools_dso.find_dso('my.pkg.libs.adso')
+    >>> lib = ctypes.CDLL(fname, , ctypes.RTLD_GLOBAL)
+    """
+    if package is None:
+        package = _auto_pkg()
+    mod = dylink_prepare_dso(dso, package=package)
+    return mod.sofilename if so else mod.filename
+
+
+
+def cli_info(args):
+    mod = import_dsoinfo(args.dso)
+    if args.var:
+        print(getattr(mod, args.var))
+    else:
+        for var in dir(mod):
+            if not var.startswith('_'):
+                print('{} = {!r}'.format(var, getattr(mod, var)))
+
+def getargs():
+    from argparse import ArgumentParser
+    P = ArgumentParser()
+    P.add_argument('-v', '--debug', dest='level', default=logging.INFO,
+                    action='store_const', const=logging.DEBUG)
+    SP = P.add_subparsers()
+    S = SP.add_parser('info')
+    S.add_argument('dso')
+    S.add_argument('var', nargs='?')
+    S.set_defaults(func=cli_info)
+
+    return P
+
+def main():
+    args = getargs().parse_args()
+    logging.basicConfig(level=args.level)
+    logging.debug('PYTHONPATH=')
+    for ent in sys.path:
+        logging.debug('  '+ent)
+    args.func(args)
+
+if __name__=='__main__':
+    main()