pyx.build: Provide DSO that should be used to build DSOs that use/link-to libgolang

Providing pygolang-specific DSO is needed because using just
setuptools_dso.DSO in external project will result in that e.g.
"<golang/libgolang.h>" won't be found.

MANIFEST.in

@@ -4,6 +4,7 @@ include golang/runtime/libgolang.cpp
 include golang/runtime/libpyxruntime.cpp
 include golang/pyx/runtime.h
 include golang/pyx/runtime.cpp
+include golang/pyx/testprog/golang_dso_user/dsouser/dso.cpp
 include golang/context.h
 include golang/context.cpp
 include golang/cxx.h

golang/pyx/build.py

@@ -119,15 +119,23 @@ def setup(**kw):
     finally:
         setuptools_dso.build_ext = _
 
-# Extension should be used to build extensions that use pygolang.
+# DSO should be used to build DSOs that use libgolang.
 #
 # For example:
 #
 #   setup(
 #       ...
-#       ext_modules = [Extension('mypkg.mymod', ['mypkg/mymod.pyx'])],
+#       x_dsos = [DSO('mypkg.mydso', ['mypkg/mydso.cpp'])],
 #   )
-def Extension(name, sources, **kw):
+def DSO(name, sources, **kw):
+    _, kw = _with_build_defaults(kw)
+    dso = setuptools_dso.DSO(name, sources, **kw)
+    return dso
+
+
+# _with_build_defaults returns copy of kw amended with build options common for
+# both DSO and Extension.
+def _with_build_defaults(kw):   # -> (pygo, kw')
     # find pygolang root
     gopkg = _findpkg("golang")
     pygo  = dirname(gopkg.path) # .../pygolang/golang -> .../pygolang
@@ -160,31 +168,50 @@ def Extension(name, sources, **kw):
     _[0:0] = ccdefault              # if another e.g. -std=... was already there -
     kw['extra_compile_args'] = _    # - it will override us
 
-    # some depends to workaround a bit lack of proper dependency tracking in
-    # setuptools/distutils.
+    # some C-level depends to workaround a bit lack of proper dependency
+    # tracking in setuptools/distutils.
     dependv = kw.get('depends', [])[:]
     dependv.append('%s/golang/libgolang.h'  % pygo)
+    dependv.append('%s/golang/context.h'    % pygo)
+    dependv.append('%s/golang/cxx.h'        % pygo)
+    dependv.append('%s/golang/errors.h'     % pygo)
+    dependv.append('%s/golang/fmt.h'        % pygo)
+    dependv.append('%s/golang/strings.h'    % pygo)
+    dependv.append('%s/golang/sync.h'       % pygo)
+    dependv.append('%s/golang/time.h'       % pygo)
+    dependv.append('%s/golang/pyx/runtime.h'    % pygo)
+    kw['depends'] = dependv
+
+    return pygo, kw
+
+
+# Extension should be used to build extensions that use pygolang.
+#
+# For example:
+#
+#   setup(
+#       ...
+#       ext_modules = [Extension('mypkg.mymod', ['mypkg/mymod.pyx'])],
+#   )
+def Extension(name, sources, **kw):
+    pygo, kw = _with_build_defaults(kw)
+
+    # some pyx-level depends to workaround a bit lack of proper dependency
+    # tracking in setuptools/distutils.
+    dependv = kw.get('depends', [])[:]
     dependv.append('%s/golang/_golang.pxd'  % pygo)
     dependv.append('%s/golang/__init__.pxd' % pygo)
-    dependv.append('%s/golang/context.h'    % pygo)
     dependv.append('%s/golang/context.pxd'  % pygo)
     dependv.append('%s/golang/_context.pxd' % pygo)
-    dependv.append('%s/golang/cxx.h'        % pygo)
     dependv.append('%s/golang/cxx.pxd'      % pygo)
-    dependv.append('%s/golang/errors.h'     % pygo)
     dependv.append('%s/golang/errors.pxd'   % pygo)
     dependv.append('%s/golang/_errors.pxd'  % pygo)
-    dependv.append('%s/golang/fmt.h'        % pygo)
     dependv.append('%s/golang/fmt.pxd'      % pygo)
-    dependv.append('%s/golang/strings.h'    % pygo)
     dependv.append('%s/golang/strings.pxd'  % pygo)
-    dependv.append('%s/golang/sync.h'       % pygo)
     dependv.append('%s/golang/sync.pxd'     % pygo)
     dependv.append('%s/golang/_sync.pxd'    % pygo)
-    dependv.append('%s/golang/time.h'       % pygo)
     dependv.append('%s/golang/time.pxd'     % pygo)
     dependv.append('%s/golang/_time.pxd'    % pygo)
-    dependv.append('%s/golang/pyx/runtime.h'    % pygo)
     dependv.append('%s/golang/pyx/runtime.pxd'  % pygo)
     kw['depends'] = dependv
 

golang/pyx/build_test.py

@@ -41,6 +41,20 @@ def test_pyx_build():
     assert _ == b"test.pyx: OK\n"
 
 
+# verify that we can build/run external dso that uses libgolang.
+def test_dso_build():
+    dsouser = testprog + "/golang_dso_user"
+    pyrun(["setup.py", "build_dso", "-i"], cwd=dsouser)
+    pyrun(["setup.py", "build_ext", "-i"], cwd=dsouser)
+
+    # run built test.
+    _ = pyout(["-c",
+        # XXX `import golang` is a hack - see test_pyx_build for details.
+        "import golang;" +
+        "from dsouser import test; test.main()"], cwd=dsouser)
+    assert _ == b"dso.cpp: OK\n"
+
+
 # verify that custom classes can be used via cmdclass
 def test_pyx_build_cmdclass():
     _ = pyout(["cmdclass_custom.py", "build_ext"], cwd=testprog)

golang/pyx/testprog/golang_dso_user/dsouser/.gitignore

+/test.cpp

golang/pyx/testprog/golang_dso_user/dsouser/dso.cpp

+// Copyright (C) 2019  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+// Small library that uses a bit of libgolang features, mainly to verify
+// that external project can build against libgolang.
+
+#include <golang/libgolang.h>
+using namespace golang;
+
+#include <stdio.h>
+
+void dsotest() {
+    chan<int> ch = makechan<int>();
+    ch.close();
+
+    printf("dso.cpp: OK\n");
+}

golang/pyx/testprog/golang_dso_user/dsouser/test.pyx

+# cython: language_level=2
+#
+# Copyright (C) 2019  Nexedi SA and Contributors.
+#                     Kirill Smelkov <kirr@nexedi.com>
+#
+# This program is free software: you can Use, Study, Modify and Redistribute
+# it under the terms of the GNU General Public License version 3, or (at your
+# option) any later version, as published by the Free Software Foundation.
+#
+# You can also Link and Combine this program with other software covered by
+# the terms of any of the Free Software licenses or any of the Open Source
+# Initiative approved licenses and Convey the resulting work. Corresponding
+# source of such a combination shall include the source code for all other
+# software used.
+#
+# This program is distributed WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See COPYING file for full licensing terms.
+# See https://www.nexedi.com/licensing for rationale and options.
+
+# Small test driver that calls dso.so .
+
+cdef extern from * nogil:
+    """
+    void dsotest();
+    """
+    void dsotest()
+
+def main():
+    dsotest()

golang/pyx/testprog/golang_dso_user/pyproject.toml

+[build-system]
+requires = ["pygolang[pyx.build]"]

golang/pyx/testprog/golang_dso_user/setup.py

+# Copyright (C) 2019  Nexedi SA and Contributors.
+#                     Kirill Smelkov <kirr@nexedi.com>
+#
+# This program is free software: you can Use, Study, Modify and Redistribute
+# it under the terms of the GNU General Public License version 3, or (at your
+# option) any later version, as published by the Free Software Foundation.
+#
+# You can also Link and Combine this program with other software covered by
+# the terms of any of the Free Software licenses or any of the Open Source
+# Initiative approved licenses and Convey the resulting work. Corresponding
+# source of such a combination shall include the source code for all other
+# software used.
+#
+# This program is distributed WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+#
+# See COPYING file for full licensing terms.
+# See https://www.nexedi.com/licensing for rationale and options.
+"""Demo package that links to and uses libgolang from a DSO."""
+
+from golang.pyx.build import setup, DSO, Extension
+
+setup(
+    name        = 'golang_dso_user',
+    description = 'test project that uses libgolang from a dso',
+
+    x_dsos      = [DSO('dsouser.dso', ['dsouser/dso.cpp'])],
+    ext_modules = [Extension('dsouser.test',
+                    ['dsouser/test.pyx'],
+                    dsos = ['dsouser.dso'])],
+)