llvm/utils/gn/gn.py

   1 #!/usr/bin/env python3
   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
  21     if sys.platform == "darwin":
  22         return "mac-amd64" if platform.machine() != "arm64" else "mac-arm64"
  23     if platform.machine() not in ("AMD64", "x86_64"):
  24         return None
  25     if sys.platform.startswith("linux"):
  26         return "linux-amd64"
  27     if sys.platform == "win32":
  28         return "windows-amd64"
  29
  30
  31 def print_no_gn(mention_get):
  32     print("gn binary not found in PATH")
  33     if mention_get:
  34         print("run llvm/utils/gn/get.py to download a binary and try again, or")
  35     print("follow https://gn.googlesource.com/gn/#getting-started")
  36     return 1
  37
  38
  39 def main():
  40     # Find real gn executable.
  41     gn = "gn"
  42     if (
  43         subprocess.call(
  44             "gn --version",
  45             stdout=open(os.devnull, "w"),
  46             stderr=subprocess.STDOUT,
  47             shell=True,
  48         )
  49         != 0
  50     ):
  51         # Not on path. See if get.py downloaded a prebuilt binary and run that
  52         # if it's there, or suggest to run get.py if it isn't.
  53         platform = get_platform()
  54         if not platform:
  55             return print_no_gn(mention_get=False)
  56         gn = os.path.join(os.path.dirname(__file__), "bin", platform, "gn")
  57         if not os.path.exists(gn + (".exe" if sys.platform == "win32" else "")):
  58             return print_no_gn(mention_get=True)
  59
  60     # Compute --dotfile= and --root= args to add.
  61     extra_args = []
  62     gn_main_arg = next((x for x in sys.argv[1:] if not x.startswith("-")), None)
  63     if gn_main_arg != "help":  # `gn help` gets confused by the switches.
  64         cwd = os.getcwd()
  65         dotfile = os.path.relpath(os.path.join(THIS_DIR, ".gn"), cwd)
  66         root = os.path.relpath(ROOT_DIR, cwd)
  67         extra_args = ["--dotfile=" + dotfile, "--root=" + root]
  68
  69     # Run GN command with --dotfile= and --root= added.
  70     cmd = [gn] + extra_args + sys.argv[1:]
  71     sys.exit(subprocess.call(cmd))
  72
  73
  74 if __name__ == "__main__":
  75     main()