libgolang: Export _runtime internally

Package os will need to access runtime operations to implement IO.

/reviewed-on nexedi/pygolang!17

MANIFEST.in

@@ -5,6 +5,7 @@ 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/runtime/internal.h
 include golang/context.h
 include golang/context.cpp
 include golang/cxx.h

golang/pyx/build.py

@@ -173,6 +173,7 @@ def _with_build_defaults(kw):   # -> (pygo, kw')
     dependv = kw.get('depends', [])[:]
     dependv.extend(['%s/golang/%s' % (pygo, _) for _ in [
         'libgolang.h',
+        'runtime/internal.h',
         'context.h',
         'cxx.h',
         'errors.h',

golang/runtime/internal.h

+#ifndef _NXD_LIBGOLANG_RUNTIME_INTERNAL_H
+#define _NXD_LIBGOLANG_RUNTIME_INTERNAL_H
+
+// Copyright (C) 2021-2022  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.
+
+// Header runtime/internal.h is used internally by libgolang.
+
+#include <golang/libgolang.h>
+
+// golang::internal::
+namespace golang {
+namespace internal {
+
+extern const _libgolang_runtime_ops* _runtime;
+
+}}  // golang::internal::
+
+#endif  // _NXD_LIBGOLANG_RUNTIME_INTERNAL_H

golang/runtime/libgolang.cpp

-// Copyright (C) 2018-2020  Nexedi SA and Contributors.
+// Copyright (C) 2018-2022  Nexedi SA and Contributors.
 //                          Kirill Smelkov <kirr@nexedi.com>
 //
 // This program is free software: you can Use, Study, Modify and Redistribute
@@ -28,6 +28,7 @@
 // - because Cython (currently ?) does not allow to add methods to `cdef struct`.
 
 #include "golang/libgolang.h"
+#include "golang/runtime/internal.h"
 #include "golang/sync.h"
 #include "golang/time.h"
 
@@ -112,7 +113,10 @@ struct Bug : exception {
 // ---- runtime ----
 
 // initially nil to crash if runtime was not initialized
-static const _libgolang_runtime_ops *_runtime = nil;
+namespace internal {
+const _libgolang_runtime_ops *_runtime = nil;
+}
+using internal::_runtime;
 
 void _libgolang_init(const _libgolang_runtime_ops *runtime_ops) {
     if (_runtime != nil) // XXX better check atomically

setup.py

@@ -206,6 +206,7 @@ setup(
                          'golang/time.cpp'],
                         depends = [
                             'golang/libgolang.h',
+                            'golang/runtime/internal.h',
                             'golang/context.h',
                             'golang/cxx.h',
                             'golang/errors.h',