gen_angle_gn_info_json.py

#!/usr/bin/env python

# Copyright 2018 The ANGLE Project Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# This tool will create a json description of the GN build environment that
# can then be used by gen_angle_android_bp.py to build an Android.bp file for
# the Android Soong build system.
# The input to this tool is a list of GN labels for which to capture the build
# information in json:
#
# Generating angle.json needs to be done from within a Chromium build:
# cd <chromium>/src
# gen_angle_gn_info_json.py //third_party/angle:libGLESv2 //third_party/angle:libEGL
#
# This will output an angle.json that can be copied to the angle directory
# within Android.
#
# Optional arguments:
# --gn_out <file> GN output config to use (e.g., out/Default or out/Debug.)
# --output <file> json file to create, default is angle.json
#

importargparse
importjson
importlogging
importsubprocess
importsys


defget_json_description(gn_out, target_name):
try:
text_desc=subprocess.check_output(['gn', 'desc', '--format=json', gn_out, target_name])
exceptsubprocess.CalledProcessErrorase:
logging.error("e.retcode = %s"%e.returncode)
logging.error("e.cmd = %s"%e.cmd)
logging.error("e.output = %s"%e.output)
try:
json_out=json.loads(text_desc)
exceptValueError:
raiseValueError("Unable to decode JSON\ncmd: %s\noutput:\n%s"% (subprocess.list2cmdline(
 ['gn', 'desc', '--format=json', gn_out, target_name]), text_desc))

returnjson_out


defload_json_deps(desc, gn_out, target_name, all_desc, indent=" "):
"""Extracts dependencies from the given target json description
 and recursively extracts json descriptions.

 desc: json description for target_name that includes dependencies
 gn_out: GN output file with configuration info
 target_name: name of target in desc to lookup deps
 all_desc: dependent descriptions added here
 indent: Print with indent to show recursion depth
 """
target=desc[target_name]
text_descriptions= []
fordepintarget.get('deps', []):
ifdepnotinall_desc:
logging.debug("dep: %s%s"% (indent, dep))
new_desc=get_json_description(gn_out, dep)
all_desc[dep] =new_desc[dep]
load_json_deps(new_desc, gn_out, dep, all_desc, indent+" ")
else:
logging.debug("dup: %s%s"% (indent, dep))


defcreate_build_description(gn_out, targets):
"""Creates the JSON build description by running GN."""

logging.debug("targets = %s"%targets)
json_descriptions= {}
fortargetintargets:
logging.debug("target: %s"% (target))
target_desc=get_json_description(gn_out, target)
if (targetintarget_descandtargetnotinjson_descriptions):
json_descriptions[target] =target_desc[target]
load_json_deps(target_desc, gn_out, target, json_descriptions)
else:
logging.debug("Invalid target: %s"%target)
returnjson_descriptions


defmain():
logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)
parser=argparse.ArgumentParser(
description='Generate json build information from a GN description.')
parser.add_argument(
'--gn_out',
help='GN output config to use (e.g., out/Default or out/Debug.)',
default='out/Default',
 )
parser.add_argument(
'--output',
help='json file to create',
default='angle.json',
 )
parser.add_argument(
'targets',
nargs=argparse.REMAINDER,
help='Targets to include in the json (e.g., "//libEGL")')
args=parser.parse_args()

desc=create_build_description(args.gn_out, args.targets)
fh=open(args.output, "w")
fh.write(json.dumps(desc, indent=4, sort_keys=True))
fh.close()

print("Output written to: %s"%args.output)


if__name__=='__main__':
sys.exit(main())