build_platform.py

#
# Copyright (C) 2019 The Android Open Source Project
#
# 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.
#

"""build_platform provides various ways of naming the environment we are
building under for the purpose of selecting the correct paths and targets.
"""

import platform

def system() -> str:
    """Returns a canonicalized OS type of the machine executing the script.
    Will be one of 'linux', 'darwin', or 'windows'."""
    sys = platform.system()
    if sys == "Linux":
        return "linux"
    if sys == "Darwin":
        return "darwin"
    if sys == "Windows":
        return "windows"
    raise RuntimeError("Unknown System: " + sys)

def is_linux() -> bool:
    return platform.system() == "Linux"

def is_darwin() -> bool:
    return platform.system() == "Darwin"

def is_windows() -> bool:
    return platform.system() == "Windows"

def prebuilt() -> str:
    """Returns the prebuilt subdirectory for prebuilts which do not use
    subarch specialization."""
    return system() + "-x86"

def prebuilt_full() -> str:
    """Returns the prebuilt subdirectory for prebuilts which have subarch
    specialization available.
    """
    return system() + "-x86_64"

def triple() -> str:
    """Returns the target triple of the build environment."""
    build_os = system()
    if build_os == "linux":
        return "x86_64-unknown-linux-gnu"
    if build_os == "darwin":
        return "x86_64-apple-darwin"
    if build_os == "windows":
        return "x86_64-pc-windows-gnu"
    raise RuntimeError("Unknown OS: " + build_os)

def rpath_origin() -> str:
    """Returns the string used to indicate the root loader context"""
    if is_darwin():
        return "@loader_path"
    else:
        return "$ORIGIN"