blob: 7cf5a99cec3a576f973775addfe1a66e739dc626 [file] [log] [blame]
#!/usr/bin/env python3
# Copyright 2023 Google LLC
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# This script runs bazel build [target] [additional_arg] [additional_arg]
# and then copies each of the specified outputs from the bazel-bin output
# folder under the current working directory. This allows GN to shell out
# to Bazel to generate or compile files, but still have them show up where
# GN expects (in the output folder).
# The first argument passed in to this script is the Bazel target.
# subsequent arguments are treated either as Bazel flags (if they start with
# --) or output files to copy (if they do not).
# Output files may contain an equals sign (=), which means the first part is
# the Bazel file to copy and the second part is where to copy it. If omitted,
# the file will go immediately under the GN output directory.
import hashlib
import os
import shutil
import subprocess
import sys
target = sys.argv[1]
outputs = {}
bazel_args = []
for arg in sys.argv[2:]:
if arg.startswith("--"):
if "=" in arg:
# "../../bazel-bin/src/ports/ffi.h=src/core/ffi.h" means to
# copy ../../bazel-bin/src/ports/ffi.h to
# $GN_OUTPUT/src/core/ffi.h
bazel_file, output_path = arg.split("=")
outputs[bazel_file] = output_path
# "../../bazel-bin/src/ports/libstuff.a" means to copy
# ../../bazel-bin/src/ports/libstuff.a to
# $GN_OUTPUT/libstuff.a
outputs[arg] = os.path.basename(arg)
print("Invoking bazelisk from ", os.getcwd())
# Forward the remaining args to the bazel invocation["bazelisk", "build", target ] + bazel_args, check=True)
for bazel_file, output_path in outputs.items():
# GN expects files to be created underneath the output directory from which
# this script is invoked.
expected_output = os.path.join(os.getcwd(), output_path)
if not os.path.exists(expected_output):
shutil.copyfile(bazel_file, expected_output)
os.chmod(expected_output, 0o755)
# GN uses timestamps to determine if it should re-build a file. If the
# two files match (via hash) we should not re-copy the output, which would
# re-trigger subsequent rebuilds.
created_hash = hashlib.sha256(open(bazel_file, 'rb').read()).hexdigest()
existing_hash = hashlib.sha256(open(expected_output, 'rb').read()).hexdigest()
if created_hash != existing_hash:
shutil.copyfile(bazel_file, expected_output)
os.chmod(expected_output, 0o755)