depot_tools/detect_host_arch.py

#!/usr/bin/env python3
# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Outputs host CPU architecture in format recognized by gyp."""

from __future__ import print_function

import platform
import re

def HostArch():
  """Returns the host architecture with a predictable string."""
  host_arch = platform.machine().lower()
  host_processor = platform.processor().lower()

  # Convert machine type to format recognized by gyp.
  if re.match(r'i.86', host_arch) or host_arch == 'i86pc':
    host_arch = 'x86'
  elif host_arch in ['x86_64', 'amd64']:
    host_arch = 'x64'
  elif host_arch == 'arm64' or host_arch.startswith('aarch64'):
    host_arch = 'arm64'
  elif host_arch.startswith('arm'):
    host_arch = 'arm'
  elif host_arch.startswith('mips64'):
    host_arch = 'mips64'
  elif host_arch.startswith('mips'):
    host_arch = 'mips'
  elif host_arch.startswith('ppc') or host_processor == 'powerpc':
    host_arch = 'ppc'
  elif host_arch.startswith('s390'):
    host_arch = 's390'
  elif host_arch.startswith('riscv'):
    host_arch = 'riscv64'

  if host_arch == 'arm64':
    host_platform = platform.architecture()
    if len(host_platform) > 1:
      if host_platform[1].lower() == 'windowspe':
        # Special case for Windows on Arm: windows-386 packages no longer work
        # so use the x64 emulation (this restricts us to Windows 11). Python
        # 32-bit returns the host_arch as arm64, 64-bit does not.
        return 'x64'

  # platform.machine is based on running kernel. It's possible to use 64-bit
  # kernel with 32-bit userland, e.g. to give linker slightly more memory.
  # Distinguish between different userland bitness by querying
  # the python binary.
  if host_arch == 'x64' and platform.architecture()[0] == '32bit':
    host_arch = 'x86'
  if host_arch == 'arm64' and platform.architecture()[0] == '32bit':
    host_arch = 'arm'

  return host_arch

def DoMain(_):
  """Hook to be called from gyp without starting a separate python
  interpreter."""
  return HostArch()

if __name__ == '__main__':
  print(DoMain([]))