xref: /llvm-project/llvm/utils/gn/get.py (revision b71edfaa4ec3c998aadb35255ce2f60bba2940b0)
1#!/usr/bin/env python3
2"""Downloads a prebuilt gn binary to a place where gn.py can find it."""
3
4import io
5import os
6import sys
7import urllib.request
8import zipfile
9
10
11def download_and_unpack(url, output_dir, gn):
12    """Download an archive from url and extract gn from it into output_dir."""
13    print("downloading %s ..." % url, end="")
14    sys.stdout.flush()
15    data = urllib.request.urlopen(url).read()
16    print(" done")
17    zipfile.ZipFile(io.BytesIO(data)).extract(gn, path=output_dir)
18
19
20def set_executable_bit(path):
21    mode = os.stat(path).st_mode
22    mode |= (mode & 0o444) >> 2  # Copy R bits to X.
23    os.chmod(path, mode)  # No-op on Windows.
24
25
26def get_platform():
27    import platform
28
29    if sys.platform == "darwin":
30        return "mac-amd64" if platform.machine() != "arm64" else "mac-arm64"
31    if platform.machine() not in ("AMD64", "x86_64"):
32        return None
33    if sys.platform.startswith("linux"):
34        return "linux-amd64"
35    if sys.platform == "win32":
36        return "windows-amd64"
37
38
39def main():
40    platform = get_platform()
41    if not platform:
42        print("no prebuilt binary for", sys.platform)
43        print("build it yourself with:")
44        print("  rm -rf /tmp/gn &&")
45        print("  pushd /tmp && git clone https://gn.googlesource.com/gn &&")
46        print("  cd gn && build/gen.py && ninja -C out gn && popd &&")
47        print("  cp /tmp/gn/out/gn somewhere/on/PATH")
48        return 1
49    dirname = os.path.join(os.path.dirname(__file__), "bin", platform)
50    if not os.path.exists(dirname):
51        os.makedirs(dirname)
52
53    url = "https://chrome-infra-packages.appspot.com/dl/gn/gn/%s/+/latest"
54    gn = "gn" + (".exe" if sys.platform == "win32" else "")
55    if platform == "mac-arm64":  # For https://openradar.appspot.com/FB8914243
56        try:
57            os.remove(os.path.join(dirname, gn))
58        except OSError:
59            pass
60    download_and_unpack(url % platform, dirname, gn)
61    set_executable_bit(os.path.join(dirname, gn))
62
63
64if __name__ == "__main__":
65    sys.exit(main())
66