utils/gn/gn.py

   1 #!/usr/bin/env python
   2 """Calls `gn` with the right --dotfile= and --root= arguments for LLVM."""
   3
   4 # GN normally expects a file called '.gn' at the root of the repository.
   5 # Since LLVM's GN build isn't supported, putting that file at the root
   6 # is deemed inappropriate, which requires passing --dotfile= and -root= to GN.
   7 # Since that gets old fast, this script automatically passes these arguments.
   8
   9 import os
  10 import subprocess
  11 import sys
  12
  13
  14 THIS_DIR = os.path.dirname(__file__)
  15 ROOT_DIR = os.path.join(THIS_DIR, '..', '..', '..')
  16
  17
  18 def get_platform():
  19     import platform
  20     if platform.machine() not in ('AMD64', 'x86_64'):
  21         return None
  22     if sys.platform.startswith('linux'):
  23         return 'linux-amd64'
  24     if sys.platform == 'darwin':
  25         return 'mac-amd64'
  26     if sys.platform == 'win32':
  27         return 'windows-amd64'
  28
  29
  30 def print_no_gn(mention_get):
  31     print('gn binary not found in PATH')
  32     if mention_get:
  33         print('run llvm/utils/gn/get.py to download a binary and try again, or')
  34     print('follow https://gn.googlesource.com/gn/#getting-started')
  35     return 1
  36
  37
  38 def main():
  39     # Find real gn executable.
  40     gn = 'gn'
  41     if subprocess.call('gn --version', stdout=open(os.devnull, 'w'),
  42                                        stderr=subprocess.STDOUT,
  43                                        shell=True) != 0:
  44         # Not on path. See if get.py downloaded a prebuilt binary and run that
  45         # if it's there, or suggest to run get.py if it isn't.
  46         platform = get_platform()
  47         if not platform:
  48             return print_no_gn(mention_get=False)
  49         gn = os.path.join(os.path.dirname(__file__), 'bin', platform, 'gn')
  50         if not os.path.exists(gn + ('.exe' if sys.platform == 'win32' else '')):
  51             return print_no_gn(mention_get=True)
  52
  53     # Compute --dotfile= and --root= args to add.
  54     extra_args = []
  55     gn_main_arg = next((x for x in sys.argv[1:] if not x.startswith('-')), None)
  56     if gn_main_arg != 'help':  # `gn help` gets confused by the switches.
  57         cwd = os.getcwd()
  58         dotfile = os.path.relpath(os.path.join(THIS_DIR, '.gn'), cwd)
  59         root = os.path.relpath(ROOT_DIR, cwd)
  60         extra_args = [ '--dotfile=' + dotfile, '--root=' + root ]
  61
  62     # Run GN command with --dotfile= and --root= added.
  63     cmd = [gn] + extra_args + sys.argv[1:]
  64     sys.exit(subprocess.call(cmd))
  65
  66
  67 if __name__ == '__main__':
  68     main()