support.py

# Copyright 2016 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os
import os.path
import shutil
import sys
import tempfile

from distutils import errors

import commands

C_PYTHON_DEV = """
#include <Python.h>
int main(int argc, char **argv) { return 0; }
"""
C_PYTHON_DEV_ERROR_MESSAGE = """
Could not find <Python.h>. This could mean the following:
 * You're on Ubuntu and haven't run `apt-get install <PY_REPR>-dev`.
 * You're on RHEL/Fedora and haven't run `yum install <PY_REPR>-devel` or
 `dnf install <PY_REPR>-devel` (make sure you also have redhat-rpm-config
 installed)
 * You're on Mac OS X and the usual Python framework was somehow corrupted
 (check your environment variables or try re-installing?)
 * You're on Windows and your Python installation was somehow corrupted
 (check your environment variables or try re-installing?)
"""
if sys.version_info[0] == 2:
 PYTHON_REPRESENTATION = 'python'
elif sys.version_info[0] == 3:
 PYTHON_REPRESENTATION = 'python3'
else:
 raise NotImplementedError('Unsupported Python version: %s' % sys.version)

C_CHECKS = {
 C_PYTHON_DEV:
 C_PYTHON_DEV_ERROR_MESSAGE.replace('<PY_REPR>', PYTHON_REPRESENTATION),
}


def _compile(compiler, source_string):
 tempdir = tempfile.mkdtemp()
 cpath = os.path.join(tempdir, 'a.c')
 with open(cpath, 'w') as cfile:
 cfile.write(source_string)
 try:
 compiler.compile([cpath])
 except errors.CompileError as error:
 return error
 finally:
 shutil.rmtree(tempdir)


def _expect_compile(compiler, source_string, error_message):
 if _compile(compiler, source_string) is not None:
 sys.stderr.write(error_message)
 raise commands.CommandError(
 "Diagnostics found a compilation environment issue:\n{}".format(
 error_message))


def diagnose_compile_error(build_ext, error):
 """Attempt to diagnose an error during compilation."""
 for c_check, message in C_CHECKS.items():
 _expect_compile(build_ext.compiler, c_check, message)
 python_sources = [
 source for source in build_ext.get_source_files()
 if source.startswith('./src/python') and source.endswith('c')
 ]
 for source in python_sources:
 if not os.path.isfile(source):
 raise commands.CommandError((
 "Diagnostics found a missing Python extension source file:\n{}\n\n"
 "This is usually because the Cython sources haven't been transpiled "
 "into C yet and you're building from source.\n"
 "Try setting the environment variable "
 "`GRPC_PYTHON_BUILD_WITH_CYTHON=1` when invoking `setup.py` or "
 "when using `pip`, e.g.:\n\n"
 "pip install -rrequirements.txt\n"
 "GRPC_PYTHON_BUILD_WITH_CYTHON=1 pip install .").format(source))


def diagnose_attribute_error(build_ext, error):
 if any('_needs_stub' in arg for arg in error.args):
 raise commands.CommandError(
 "We expect a missing `_needs_stub` attribute from older versions of "
 "setuptools. Consider upgrading setuptools.")


_ERROR_DIAGNOSES = {
 errors.CompileError: diagnose_compile_error,
 AttributeError: diagnose_attribute_error,
}


def diagnose_build_ext_error(build_ext, error, formatted):
 diagnostic = _ERROR_DIAGNOSES.get(type(error))
 if diagnostic is None:
 raise commands.CommandError(
 "\n\nWe could not diagnose your build failure. If you are unable to "
 "proceed, please file an issue at http://www.github.com/grpc/grpc "
 "with `[Python install]` in the title; please attach the whole log "
 "(including everything that may have appeared above the Python "
 "backtrace).\n\n{}".format(formatted))
 else:
 diagnostic(build_ext, error)