rules_cc/tools/migration/ctoolchain_comparator.py

128 lines
4.8 KiB
Python

# Copyright 2018 The Bazel Authors. All rights reserved.
#
# 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.
r"""A script that compares 2 CToolchains from proto format.
This script accepts two files in either a CROSSTOOL proto text format or a
CToolchain proto text format. It then locates the CToolchains with the given
toolchain_identifier and checks if the resulting CToolchain objects in Java
are the same.
Example usage:
bazel run \
@rules_cc//tools/migration:ctoolchain_comparator -- \
--before=/path/to/CROSSTOOL1 \
--after=/path/to/CROSSTOOL2 \
--toolchain_identifier=id
"""
import os
from absl import app
from absl import flags
from google.protobuf import text_format
from third_party.com.github.bazelbuild.bazel.src.main.protobuf import crosstool_config_pb2
from tools.migration.ctoolchain_comparator_lib import compare_ctoolchains
flags.DEFINE_string(
"before", None,
("A text proto file containing the relevant CTooclchain before the change, "
"either a CROSSTOOL file or a single CToolchain proto text"))
flags.DEFINE_string(
"after", None,
("A text proto file containing the relevant CToolchain after the change, "
"either a CROSSTOOL file or a single CToolchain proto text"))
flags.DEFINE_string("toolchain_identifier", None,
"The identifier of the CToolchain that is being compared.")
flags.mark_flag_as_required("before")
flags.mark_flag_as_required("after")
def _to_absolute_path(path):
path = os.path.expanduser(path)
if os.path.isabs(path):
return path
else:
if "BUILD_WORKING_DIRECTORY" in os.environ:
return os.path.join(os.environ["BUILD_WORKING_DIRECTORY"], path)
else:
return path
def _find_toolchain(crosstool, toolchain_identifier):
for toolchain in crosstool.toolchain:
if toolchain.toolchain_identifier == toolchain_identifier:
return toolchain
return None
def _read_crosstool_or_ctoolchain_proto(input_file, toolchain_identifier=None):
"""Reads a proto file and finds the CToolchain with the given identifier."""
with open(input_file, "r") as f:
text = f.read()
crosstool_release = crosstool_config_pb2.CrosstoolRelease()
c_toolchain = crosstool_config_pb2.CToolchain()
try:
text_format.Merge(text, crosstool_release)
if toolchain_identifier is None:
print("CROSSTOOL proto needs a 'toolchain_identifier' specified in "
"order to be able to select the right toolchain for comparison.")
return None
toolchain = _find_toolchain(crosstool_release, toolchain_identifier)
if toolchain is None:
print(("Cannot find a CToolchain with an identifier '%s' in CROSSTOOL "
"file") % toolchain_identifier)
return None
return toolchain
except text_format.ParseError as crosstool_error:
try:
text_format.Merge(text, c_toolchain)
if (toolchain_identifier is not None and
c_toolchain.toolchain_identifier != toolchain_identifier):
print(("Expected CToolchain with identifier '%s', got CToolchain with "
"identifier '%s'" % (toolchain_identifier,
c_toolchain.toolchain_identifier)))
return None
return c_toolchain
except text_format.ParseError as toolchain_error:
print(("Error parsing file '%s':" % input_file)) # pylint: disable=superfluous-parens
print("Attempt to parse it as a CROSSTOOL proto:") # pylint: disable=superfluous-parens
print(crosstool_error) # pylint: disable=superfluous-parens
print("Attempt to parse it as a CToolchain proto:") # pylint: disable=superfluous-parens
print(toolchain_error) # pylint: disable=superfluous-parens
return None
def main(unused_argv):
before_file = _to_absolute_path(flags.FLAGS.before)
after_file = _to_absolute_path(flags.FLAGS.after)
toolchain_identifier = flags.FLAGS.toolchain_identifier
toolchain_before = _read_crosstool_or_ctoolchain_proto(
before_file, toolchain_identifier)
toolchain_after = _read_crosstool_or_ctoolchain_proto(after_file,
toolchain_identifier)
if not toolchain_before or not toolchain_after:
print("There was an error getting the required toolchains.")
exit(1)
found_difference = compare_ctoolchains(toolchain_before, toolchain_after)
if found_difference:
exit(1)
if __name__ == "__main__":
app.run(main)