diff options
Diffstat (limited to 'python/google/protobuf/internal/api_implementation.py')
-rwxr-xr-x | python/google/protobuf/internal/api_implementation.py | 38 |
1 files changed, 28 insertions, 10 deletions
diff --git a/python/google/protobuf/internal/api_implementation.py b/python/google/protobuf/internal/api_implementation.py index f7926c16..8ba4357c 100755 --- a/python/google/protobuf/internal/api_implementation.py +++ b/python/google/protobuf/internal/api_implementation.py @@ -40,14 +40,33 @@ try: # The compile-time constants in the _api_implementation module can be used to # switch to a certain implementation of the Python API at build time. _api_version = _api_implementation.api_version - del _api_implementation + _proto_extension_modules_exist_in_build = True except ImportError: - _api_version = 0 + _api_version = -1 # Unspecified by compiler flags. + _proto_extension_modules_exist_in_build = False + +if _api_version == 1: + raise ValueError('api_version=1 is no longer supported.') +if _api_version < 0: # Still unspecified? + try: + # The presence of this module in a build allows the proto implementation to + # be upgraded merely via build deps rather than a compiler flag or the + # runtime environment variable. + # pylint: disable=g-import-not-at-top + from google.protobuf import _use_fast_cpp_protos + # Work around a known issue in the classic bootstrap .par import hook. + if not _use_fast_cpp_protos: + raise ImportError('_use_fast_cpp_protos import succeeded but was None') + del _use_fast_cpp_protos + _api_version = 2 + except ImportError: + if _proto_extension_modules_exist_in_build: + if sys.version_info[0] >= 3: # Python 3 defaults to C++ impl v2. + _api_version = 2 + # TODO(b/17427486): Make Python 2 default to C++ impl v2. _default_implementation_type = ( - 'python' if _api_version == 0 else 'cpp') -_default_version_str = ( - '1' if _api_version <= 1 else '2') + 'python' if _api_version <= 0 else 'cpp') # This environment variable can be used to switch to a certain implementation # of the Python API, overriding the compile-time constants in the @@ -64,13 +83,12 @@ if _implementation_type != 'python': # _api_implementation module. Right now only 1 and 2 are valid values. Any other # value will be ignored. _implementation_version_str = os.getenv( - 'PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION', - _default_version_str) + 'PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION', '2') -if _implementation_version_str not in ('1', '2'): +if _implementation_version_str != '2': raise ValueError( - "unsupported PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION: '" + - _implementation_version_str + "' (supported versions: 1, 2)" + 'unsupported PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION: "' + + _implementation_version_str + '" (supported versions: 2)' ) _implementation_version = int(_implementation_version_str) |