CI: ensure DSO only package isn't purelib

.github/workflows/build.yml

@@ -99,6 +99,19 @@ jobs:
           python setup.py -v build_ext -i
           (cd src && python -m dsodemo.cli)
           cd ..
+      - name: Test Example DSO only
+        shell: bash
+        run: |
+          set -x
+          cd example
+          python setup.py clean -a
+          git clean -fdx .
+          rm -f dist/*.whl
+          python setup-dso-only.py -v bdist_wheel
+          python -m wheel unpack -d junk dist/*.whl
+          find junk
+          ls junk/*/*.dist-info/WHEEL
+          ! ls junk/*/*/purelib
 
   manylinux:
     runs-on: ubuntu-latest

example/setup-dso-only.py

+#!/usr/bin/env python
+
+from setuptools_dso import DSO, Extension, setup
+from setuptools_dso.probe import ProbeToolchain
+
+def define_DSOs(cmd):
+    # 'cmd' is instance of distutils Command with attributes:
+    # 'build_lib', 'build_temp', 'inplace', 'distribution', etc.
+
+    # example of inspecting the target toolchain.
+    # could be used to alter source list, macro definitions, or compiler flags.
+    probe = ProbeToolchain()
+    assert probe.try_compile('#include <stdlib.h>')
+    assert not probe.try_compile('intentionally invalid syntax')
+    assert probe.check_include('stdlib.h')
+    assert not probe.check_include('no-such-header.h')
+    assert probe.sizeof('short')==2
+    assert probe.check_symbol('RAND_MAX', headers=['stdlib.h'])
+    assert probe.check_symbol('abort', headers=['stdlib.h'])
+    assert not probe.check_symbol('intentionally_undeclared_symbol', headers=['stdlib.h'])
+
+    dso = DSO('dsodemo.lib.demo', ['src/foo.c', 'src/bar.cpp'],
+        define_macros = [('BUILD_FOO', None)],
+        # demonstrate passing other compiler flags, either conditionally or not.
+        # these are not actually used.
+        extra_compile_args = ['-DALL'],
+        lang_compile_args = {
+            'c':['-DISC'],
+            'c++':['-DISCXX'],
+        },
+        # demonstrate how to set an SONAME.
+        # eg. on linux the result will be two files:
+        #   dsodemo/lib/libdemo.so
+        #   dsodemo/lib/libdemo.so.1.0
+        soversion='1.0',
+    )
+
+    return [dso]
+
+ext = Extension('dsodemo.ext.dtest', ['src/extension.cpp'],
+    dsos=['dsodemo.lib.demo'],
+)
+
+setup(
+    name='dsodemo',
+    version="0.1",
+    # 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'},
+    # 'x_dsos' may be None, a list of DSO instances,
+    # or a callable returning a list of DSOs.
+    #x_dsos = [dso],
+    x_dsos = define_DSOs,
+)