Core mojo API for python.

Review URL: https://codereview.chromium.org/377293002

Cr-Commit-Position: refs/heads/master@{#291701}

mojo/BUILD.gn

@@ -13,6 +13,12 @@ group("mojo") {
     "//mojo/services",
     "//mojo/shell:mojo_shell",
   ]
+
+  if (is_linux) {
+    deps += [
+      "//mojo/python",
+    ]
+  }
 }
 
 group("tests") {

mojo/mojo.gyp

@@ -87,6 +87,13 @@
             'mojo_dbus_echo_service',
           ],
         }],
+        ['component != "shared_library" and OS == "linux"', {
+          'dependencies': [
+            'mojo_python_embedder',
+            'mojo_python_system',
+            'mojo_python',
+          ],
+        }],
       ]
     },
     {
@@ -531,5 +538,77 @@
         },
       ],
     }],
+    ['component!="shared_library" and OS=="linux"', {
+      'targets': [
+        {
+          'target_name': 'mojo_python_system',
+          'variables': {
+            'python_base_module': 'mojo',
+            'python_cython_module': 'system',
+          },
+          'sources': [
+            'public/python/mojo/c_core.pxd',
+            'public/python/mojo/system.pyx',
+          ],
+          'dependencies': [
+            'mojo_base.gyp:mojo_system',
+          ],
+          'includes': [ '../third_party/cython/cython_compiler.gypi' ],
+        },
+        {
+          'target_name': 'mojo_python_embedder',
+          'type': 'loadable_module',
+          'variables': {
+            'python_base_module': 'mojo',
+            'python_cython_module': 'embedder',
+          },
+          'sources': [
+            'python/system/mojo/embedder.pyx',
+          ],
+          'dependencies': [
+            'mojo_base.gyp:mojo_system_impl',
+          ],
+          'includes': [ '../third_party/cython/cython_compiler.gypi' ],
+        },
+        {
+          'target_name': 'mojo_python',
+          'type': 'none',
+          'variables': {
+            'python_base_module': 'mojo',
+          },
+          'sources': [
+            'public/python/mojo/__init__.py',
+          ],
+          'dependencies': [
+            'mojo_python_embedder',
+            'mojo_python_system',
+          ],
+          'includes': [ '../third_party/cython/python_module.gypi' ],
+        },
+        {
+          'target_name': 'mojo_python_unittests',
+          'type': 'none',
+          'actions': [
+            {
+              'action_name': 'run_mojo_python_unittests',
+              'inputs': [
+                'python/tests/test_core.py',
+                '<(SHARED_INTERMEDIATE_DIR)/mojo_python_py_module.stamp',
+                '<(PRODUCT_DIR)/python/mojo/__init__.py',
+              ],
+              'outputs': [
+                'none',
+              ],
+              'action': [
+                'python', '<@(_inputs)', '<(PRODUCT_DIR)/python',
+              ],
+            },
+          ],
+          'dependency': [
+            'mojo_python',
+          ],
+        },
+      ],
+    }],
   ],
 }

mojo/public/BUILD.gn

@@ -14,6 +14,12 @@ group("public") {
     "//mojo/public/js/bindings",
   ]
 
+  if (is_linux) {
+    deps += [
+      "//mojo/public/python",
+    ]
+  }
+
   if (is_android) {
     deps += [
       "//mojo/public/java:system",

mojo/public/python/BUILD.gn

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//third_party/cython/rules.gni")
+
+group("python") {
+  deps = [
+    ":base",
+    ":system",
+  ]
+}
+
+python_binary_module("system") {
+  python_base_module = "mojo"
+  sources = [
+    "mojo/c_core.pxd",
+    "mojo/system.pyx",
+  ]
+  deps = [
+    "//mojo/public/c/system",
+    ":base",
+  ]
+}
+
+copy("base") {
+  sources = [
+    "mojo/__init__.py",
+  ]
+  outputs = [
+    "$root_out_dir/python/mojo/__init__.py",
+  ]
+}

mojo/public/python/mojo/__init__.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.

mojo/public/python/mojo/c_core.pxd

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# distutils: language = c++
+
+from cpython.buffer cimport PyBUF_CONTIG
+from cpython.buffer cimport PyBUF_CONTIG_RO
+from cpython.buffer cimport Py_buffer
+from cpython.buffer cimport PyBuffer_FillInfo
+from cpython.buffer cimport PyBuffer_Release
+from cpython.buffer cimport PyObject_GetBuffer
+from cpython.mem cimport PyMem_Malloc, PyMem_Free
+from libc.stdint cimport int32_t, int64_t, uint32_t, uint64_t, uintptr_t
+
+cdef extern from "third_party/cython/python_export.h":
+  pass
+
+cdef extern from "mojo/public/platform/native/system_thunks.h" nogil:
+  cdef struct MojoSystemThunks:
+    pass
+
+cdef extern size_t MojoSetSystemThunks(const MojoSystemThunks* system_thunks)
+
+cdef extern from "mojo/public/c/system/core.h" nogil:
+  # types.h
+  ctypedef int64_t MojoTimeTicks
+
+  ctypedef uint32_t MojoHandle
+  const MojoHandle MOJO_HANDLE_INVALID
+
+  ctypedef int32_t MojoResult
+  const MojoResult MOJO_RESULT_OK
+  const MojoResult MOJO_RESULT_CANCELLED
+  const MojoResult MOJO_RESULT_UNKNOWN
+  const MojoResult MOJO_RESULT_INVALID_ARGUMENT
+  const MojoResult MOJO_RESULT_DEADLINE_EXCEEDED
+  const MojoResult MOJO_RESULT_NOT_FOUND
+  const MojoResult MOJO_RESULT_ALREADY_EXISTS
+  const MojoResult MOJO_RESULT_PERMISSION_DENIED
+  const MojoResult MOJO_RESULT_RESOURCE_EXHAUSTED
+  const MojoResult MOJO_RESULT_FAILED_PRECONDITION
+  const MojoResult MOJO_RESULT_ABORTED
+  const MojoResult MOJO_RESULT_OUT_OF_RANGE
+  const MojoResult MOJO_RESULT_UNIMPLEMENTED
+  const MojoResult MOJO_RESULT_INTERNAL
+  const MojoResult MOJO_RESULT_UNAVAILABLE
+  const MojoResult MOJO_RESULT_DATA_LOSS
+  const MojoResult MOJO_RESULT_BUSY
+  const MojoResult MOJO_RESULT_SHOULD_WAIT
+
+  ctypedef uint64_t MojoDeadline
+  const MojoDeadline MOJO_DEADLINE_INDEFINITE
+
+  ctypedef uint32_t MojoHandleSignals
+  const MojoHandleSignals MOJO_HANDLE_SIGNAL_NONE
+  const MojoHandleSignals MOJO_HANDLE_SIGNAL_READABLE
+  const MojoHandleSignals MOJO_HANDLE_SIGNAL_WRITABLE
+
+  # functions.h
+  MojoTimeTicks MojoGetTimeTicksNow()
+  MojoResult MojoClose(MojoHandle handle)
+  MojoResult MojoWait(MojoHandle handle,
+                      MojoHandleSignals signals,
+                      MojoDeadline deadline)
+  MojoResult MojoWaitMany(const MojoHandle* handles,
+                          const MojoHandleSignals* signals,
+                          uint32_t num_handles,
+                          MojoDeadline deadline)
+
+  # message_pipe.h
+  ctypedef uint32_t MojoCreateMessagePipeOptionsFlags
+  const MojoCreateMessagePipeOptionsFlags MOJO_CREATE_MESSAGE_PIPE_OPTIONS_FLAG_NONE
+
+  ctypedef uint32_t MojoWriteMessageFlags
+  const MojoWriteMessageFlags MOJO_WRITE_MESSAGE_FLAG_NONE
+
+  ctypedef uint32_t MojoReadMessageFlags
+  const MojoReadMessageFlags MOJO_READ_MESSAGE_FLAG_NONE
+  const MojoReadMessageFlags MOJO_READ_MESSAGE_FLAG_MAY_DISCARD
+
+  cdef struct MojoCreateMessagePipeOptions:
+    uint32_t struct_size
+    MojoCreateMessagePipeOptionsFlags flags
+
+  MojoResult MojoCreateMessagePipe(
+      const MojoCreateMessagePipeOptions* options,
+      MojoHandle* message_pipe_handle0,
+      MojoHandle* message_pipe_handle1)
+
+  MojoResult MojoWriteMessage(
+      MojoHandle message_pipe_handle,
+      const void* bytes,
+      uint32_t num_bytes,
+      const MojoHandle* handles,
+      uint32_t num_handles,
+      MojoWriteMessageFlags flags)
+
+  MojoResult MojoReadMessage(
+      MojoHandle message_pipe_handle,
+      void* bytes,
+      uint32_t* num_bytes,
+      MojoHandle* handles,
+      uint32_t* num_handles,
+      MojoReadMessageFlags flags)
+
+  # data_pipe.h
+  ctypedef uint32_t MojoCreateDataPipeOptionsFlags
+  const MojoCreateDataPipeOptionsFlags MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE
+  const MojoCreateDataPipeOptionsFlags MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_MAY_DISCARD
+
+  cdef struct MojoCreateDataPipeOptions:
+    uint32_t struct_size
+    MojoCreateDataPipeOptionsFlags flags
+    uint32_t element_num_bytes
+    uint32_t capacity_num_bytes
+
+  ctypedef uint32_t MojoWriteDataFlags
+
+  const MojoWriteDataFlags MOJO_WRITE_DATA_FLAG_NONE
+  const MojoWriteDataFlags MOJO_WRITE_DATA_FLAG_ALL_OR_NONE
+
+  ctypedef uint32_t MojoReadDataFlags
+
+  const MojoReadDataFlags MOJO_READ_DATA_FLAG_NONE
+  const MojoReadDataFlags MOJO_READ_DATA_FLAG_ALL_OR_NONE
+  const MojoReadDataFlags MOJO_READ_DATA_FLAG_DISCARD
+  const MojoReadDataFlags MOJO_READ_DATA_FLAG_QUERY
+
+  MojoResult MojoCreateDataPipe(
+      const MojoCreateDataPipeOptions* options,
+      MojoHandle* data_pipe_producer_handle,
+      MojoHandle* data_pipe_consumer_handle)
+
+  MojoResult MojoWriteData(
+      MojoHandle data_pipe_producer_handle,
+      const void* elements,
+      uint32_t* num_bytes,
+      MojoWriteDataFlags flags)
+
+  MojoResult MojoBeginWriteData(
+      MojoHandle data_pipe_producer_handle,
+      void** buffer,
+      uint32_t* buffer_num_bytes,
+      MojoWriteDataFlags flags)
+
+  MojoResult MojoEndWriteData(
+      MojoHandle data_pipe_producer_handle,
+      uint32_t num_bytes_written)
+
+  MojoResult MojoReadData(
+      MojoHandle data_pipe_consumer_handle,
+      void* elements,
+      uint32_t* num_bytes,
+      MojoReadDataFlags flags)
+
+  MojoResult MojoBeginReadData(
+      MojoHandle data_pipe_consumer_handle,
+      const void** buffer,
+      uint32_t* buffer_num_bytes,
+      MojoReadDataFlags flags)
+
+  MojoResult MojoEndReadData(
+      MojoHandle data_pipe_consumer_handle,
+      uint32_t num_bytes_read)
+
+  # buffer.h
+  ctypedef uint32_t MojoCreateSharedBufferOptionsFlags
+  const MojoCreateSharedBufferOptionsFlags MOJO_CREATE_SHARED_BUFFER_OPTIONS_FLAG_NONE
+
+  cdef struct MojoCreateSharedBufferOptions:
+    uint32_t struct_size
+    MojoCreateSharedBufferOptionsFlags flags
+
+  ctypedef uint32_t MojoDuplicateBufferHandleOptionsFlags
+  const MojoDuplicateBufferHandleOptionsFlags MOJO_DUPLICATE_BUFFER_HANDLE_OPTIONS_FLAG_NONE
+
+  cdef struct MojoDuplicateBufferHandleOptions:
+    uint32_t struct_size
+    MojoDuplicateBufferHandleOptionsFlags flags
+
+  ctypedef uint32_t MojoMapBufferFlags
+  const MojoMapBufferFlags MOJO_MAP_BUFFER_FLAG_NONE
+
+  MojoResult MojoCreateSharedBuffer(
+      const MojoCreateSharedBufferOptions* options,
+      uint64_t num_bytes,
+      MojoHandle* shared_buffer_handle)
+
+  MojoResult MojoDuplicateBufferHandle(
+      MojoHandle buffer_handle,
+      const MojoDuplicateBufferHandleOptions* options,
+      MojoHandle* new_buffer_handle)
+
+  MojoResult MojoMapBuffer(MojoHandle buffer_handle,
+                           uint64_t offset,
+                           uint64_t num_bytes,
+                           void** buffer,
+                           MojoMapBufferFlags flags)
+
+  MojoResult MojoUnmapBuffer(void* buffer)

mojo/python/BUILD.gn

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//third_party/cython/rules.gni")
+
+group("python") {
+  deps = [
+    ":embedder",
+  ]
+}
+
+group("tests") {
+  deps = [
+    "//mojo/python/tests",
+  ]
+}
+python_binary_module("embedder") {
+  python_base_module = "mojo"
+  sources = [
+    "system/mojo/embedder.pyx",
+  ]
+  deps = [
+    "//mojo/system",
+  ]
+  datadeps = [
+    "//mojo/public/python:system",
+  ]
+}

mojo/python/system/mojo/embedder.pyx

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# distutils: language = c++
+
+from libc.stdint cimport uintptr_t
+
+from mojo import system
+
+cdef extern from "third_party/cython/python_export.h":
+  pass
+
+cdef extern from "base/memory/scoped_ptr.h":
+  cdef cppclass scoped_ptr[T]:
+    scoped_ptr(T*)
+
+cdef extern from "mojo/embedder/platform_support.h" \
+    namespace "mojo::embedder" nogil:
+  cdef cppclass PlatformSupport:
+    pass
+
+cdef extern from "mojo/embedder/simple_platform_support.h" \
+    namespace "mojo::embedder" nogil:
+  cdef cppclass SimplePlatformSupport(PlatformSupport):
+    SimplePlatformSupport()
+
+cdef extern from "mojo/embedder/embedder.h" nogil:
+  cdef void InitCEmbedder "mojo::embedder::Init"(
+      scoped_ptr[PlatformSupport] platform_support)
+
+cdef extern from "mojo/public/platform/native/system_thunks.h" nogil:
+  cdef struct MojoSystemThunks:
+    pass
+  cdef MojoSystemThunks MojoMakeSystemThunks()
+
+def init():
+  InitCEmbedder(scoped_ptr[PlatformSupport](
+      new SimplePlatformSupport()))
+  cdef MojoSystemThunks thunks = MojoMakeSystemThunks()
+  system.set_system_thunks(<uintptr_t>(&thunks))

mojo/python/tests/BUILD.gn

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//third_party/cython/rules.gni")
+
+group("tests") {
+  deps = [
+    ":test_core",
+  ]
+}
+
+action("test_core") {
+  script = "test_core.py"
+  outputs = [
+    "$root_out_dir/no_file",
+  ]
+  inputs = []
+  deps = [
+    "//mojo/public/python:system",
+    "//mojo/python:embedder",
+  ]
+  args = [ rebase_path("$root_out_dir/python", root_build_dir) ]
+}

third_party/cython/cp_python_binary_modules.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import argparse
+import os
+import shutil
+import sys
+
+def touch(fname):
+  if os.path.exists(fname):
+    os.utime(fname, None)
+  else:
+    open(fname, 'a').close()
+
+def main():
+  """Command line utility to copy python binary modules to the correct package
+  hierarchy.
+  """
+  parser = argparse.ArgumentParser(
+      description='Copy python binary modules to the correct package '
+                  'hierarchy.')
+  parser.add_argument('timestamp', help='The timetsamp file.')
+  parser.add_argument('lib_dir', help='The directory containing the modules')
+  parser.add_argument('destination_dir',
+                      help='The destination directory of the module')
+  parser.add_argument('mappings', nargs='+',
+                      help='The mapping from module to library.')
+  opts = parser.parse_args()
+
+  if not os.path.exists(opts.destination_dir):
+    os.makedirs(opts.destination_dir)
+
+  for mapping in opts.mappings:
+    [module, library] = mapping.split('=')
+    shutil.copy(os.path.join(opts.lib_dir, library),
+                os.path.join(opts.destination_dir, module))
+
+  touch(opts.timestamp)
+
+if __name__ == '__main__':
+  main()

third_party/cython/cython_compiler.gypi

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'variables': {
+    'python_flags': '<(DEPTH)/third_party/cython/python_flags.py',
+  },
+  'conditions': [
+    ['OS=="mac"', {
+      'variables': {
+        'module_prefix': '',
+        'module_suffix': '.so',
+      },
+    }, {
+      'variables': {
+        'module_prefix': '<(SHARED_LIB_PREFIX)',
+        'module_suffix': '<(SHARED_LIB_SUFFIX)',
+      },
+    }],
+  ],
+  'type': 'loadable_module',
+  'rules': [
+    {
+      'rule_name': '<(_target_name)_cython_compiler',
+      'extension': 'pyx',
+      'variables': {
+        'cython_compiler': '<(DEPTH)/third_party/cython/src/cython.py',
+      },
+      'inputs': [
+        '<(cython_compiler)',
+      ],
+      'outputs': [
+        '<(SHARED_INTERMEDIATE_DIR)/cython/<(python_base_module)/<(RULE_INPUT_ROOT).cc',
+      ],
+      'action': [
+        'python', '<(cython_compiler)',
+        '--cplus',
+        '-I<(DEPTH)',
+        '-o', '<@(_outputs)',
+        '<(RULE_INPUT_PATH)',
+      ],
+      'message': 'Generating C++ source from <(RULE_INPUT_PATH)',
+      'process_outputs_as_sources': 1,
+    }
+  ],
+  'include_dirs': [
+    '<!@(python <(python_flags) --includes)',
+    '<(DEPTH)',
+  ],
+  'libraries': [
+    '<!@(python <(python_flags) --libraries)',
+  ],
+  'cflags': [
+    '-Wno-unused-function',
+  ],
+  'xcode_settings': {
+    'WARNING_CFLAGS': [ '-Wno-unused-function' ],
+  },
+  'library_dirs': [
+    '<!@(python <(python_flags) --library_dirs)',
+  ],
+  'direct_dependent_settings': {
+    'variables': {
+      'python_binary_modules': [
+        '<(python_cython_module)<(module_suffix)=<(module_prefix)<(_target_name)<(module_suffix)',
+      ],
+    },
+  },
+  'hard_dependency': 1,
+}

third_party/cython/python_export.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#if defined(PyMODINIT_FUNC)
+#undef PyMODINIT_FUNC
+#endif
+
+#if defined(WIN32)
+#define PyMODINIT_FUNC extern "C" __declspec(dllexport) void
+#else
+#define PyMODINIT_FUNC extern "C" __attribute__((visibility("default"))) void
+#endif

third_party/cython/python_flags.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import argparse
+import os
+import sys
+
+from distutils import sysconfig
+from distutils.command import build_ext
+from distutils.dist import Distribution
+from distutils.extension import Extension
+
+def main():
+  """Command line utility to retrieve compilation options for python modules'
+  """
+  parser = argparse.ArgumentParser(
+      description='Retrieves compilation options for python modules.')
+  parser.add_argument('--gn',
+                      help='Returns all values in a format suitable for gn',
+                      action='store_true')
+  parser.add_argument('--libraries', help='Returns libraries',
+                      action='store_true')
+  parser.add_argument('--includes', help='Returns includes',
+                      action='store_true')
+  parser.add_argument('--library_dirs', help='Returns library_dirs',
+                      action='store_true')
+  opts = parser.parse_args()
+
+  ext = Extension('Dummy', [])
+  b = build_ext.build_ext(Distribution())
+  b.initialize_options()
+  b.finalize_options()
+  result = []
+  if opts.libraries:
+    libraries = b.get_libraries(ext)
+    if sys.platform == 'darwin':
+      libraries += [ '-lpython%s' % sys.version[:3] ]
+    result = result + libraries
+  if opts.includes:
+    result = result  + b.include_dirs
+  if opts.library_dirs:
+    if sys.platform == 'darwin':
+      result.append('%s/lib' % sysconfig.get_config_vars('prefix')[0])
+
+  if opts.gn:
+    for x in result:
+      print x
+  else:
+    print ''.join(['"%s"' % x for x in result])
+
+if __name__ == '__main__':
+  main()

third_party/cython/python_module.gypi

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'variables': {
+    'python_binary_modules%': [],
+    'python_module_destination': '<(PRODUCT_DIR)/python/<(python_base_module)',
+    'cp': '<(DEPTH)/third_party/cython/cp_python_binary_modules.py',
+    'timestamp': '<(SHARED_INTERMEDIATE_DIR)/<(_target_name)_py_module.stamp',
+  },
+  'rules': [
+    {
+      'rule_name': '<(_target_name)_cp_python',
+      'extension': 'py',
+      'inputs': [
+        '<(DEPTH)/build/cp.py',
+      ],
+      'outputs': [
+        '<(python_module_destination)/<(RULE_INPUT_NAME)',
+      ],
+      'action': [
+        'python',
+        '<@(_inputs)',
+        '<(RULE_INPUT_PATH)',
+        '<@(_outputs)',
+      ],
+      'message': 'Moving <(RULE_INPUT_PATH) to its destination',
+    }
+  ],
+  'actions': [
+    {
+      'action_name': '<(_target_name)_move_to_python_modules',
+      'inputs': [
+        '<(cp)',
+      ],
+      'outputs': [
+        '<(timestamp)',
+      ],
+      'action': [
+        'python',
+        '<(cp)',
+        '<(timestamp)',
+        '<(PRODUCT_DIR)',
+        '<(python_module_destination)',
+        '>@(python_binary_modules)',
+      ],
+    },
+  ],
+  'hard_dependency': 1,
+}

third_party/cython/rules.gni

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+template("python_binary_module") {
+  # Only available on linux for now.
+  assert(is_linux)
+  assert(defined(invoker.sources))
+  assert(defined(invoker.python_base_module))
+
+  cython_root = "//third_party/cython"
+  cython_script = "$cython_root/src/cython.py"
+  cython_output = "${target_out_dir}/${target_name}.cc"
+
+  generator_target_name = target_name + "_cython_compiler"
+  shared_library_name = target_name + "_shared_library"
+  config_name = target_name + "_python_config"
+
+  if (is_linux) {
+    shared_library_prefix = "lib"
+    shared_library_suffix = ".so"
+    python_module_suffix = ".so"
+  }
+
+  target_visibility = [
+    ":$generator_target_name",
+    ":$shared_library_name",
+    ":$target_name",
+  ]
+
+  action(generator_target_name) {
+    visibility = target_visibility
+    script = cython_script
+    sources = invoker.sources
+    outputs = [ cython_output ]
+    args = [
+      "--cplus",
+      "-I", rebase_path("//", root_build_dir),
+      "-o", rebase_path(cython_output, root_build_dir),
+    ] + rebase_path(sources, root_build_dir)
+  }
+
+  config(config_name) {
+    visibility = target_visibility
+    python_flags = "//third_party/cython/python_flags.py"
+    include_dirs = exec_script(python_flags,
+                               [ "--gn", "--includes" ],
+                               "list lines")
+    libs = exec_script(python_flags,
+                       [ "--gn", "--libraries" ],
+                       "list lines")
+    lib_dirs = exec_script(python_flags,
+                           [ "--gn", "--library_dirs" ],
+                           "list lines")
+  }
+
+  shared_library(shared_library_name) {
+    visibility = target_visibility
+    deps = [
+      ":$generator_target_name",
+    ]
+    if (defined(invoker.deps)) {
+      deps += invoker.deps
+    }
+    if (defined(invoker.datadeps)) {
+      datadeps = invoker.datadeps
+    }
+    sources = [ cython_output ]
+    configs += [ ":$config_name" ]
+  }
+
+  copy(target_name) {
+    python_base_module = invoker.python_base_module
+    sources = [
+      "$root_out_dir/${shared_library_prefix}${shared_library_name}${shared_library_suffix}"
+    ]
+    outputs = [
+      "$root_out_dir/python/$python_base_module/${target_name}${python_module_suffix}"
+    ]
+    deps = [
+      ":$shared_library_name"
+    ]
+  }
+}