build: add update-gyp script

Co-authored-by: Christian Clauss <cclauss@me.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Christian Clauss <cclauss@me.com>
PR-URL: #2167

update-gyp.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+
+import argparse
+import os
+import shutil
+import subprocess
+import sys
+import tarfile
+import tempfile
+import urllib.request
+
+BASE_URL = "https://github.com/nodejs/gyp-next/archive/"
+CHECKOUT_PATH = os.path.dirname(os.path.realpath(__file__))
+CHECKOUT_GYP_PATH = os.path.join(CHECKOUT_PATH, 'gyp')
+
+parser = argparse.ArgumentParser()
+parser.add_argument("tag", help="gyp tag to update to")
+args = parser.parse_args()
+
+tar_url = BASE_URL + args.tag + ".tar.gz"
+
+changed_files = subprocess.check_output(["git", "diff", "--name-only"]).strip()
+if changed_files:
+  raise Exception("Can't update gyp while you have uncommitted changes in node-gyp")
+
+with tempfile.TemporaryDirectory() as tmp_dir:
+  tar_file = os.path.join(tmp_dir, 'gyp.tar.gz')
+  unzip_target = os.path.join(tmp_dir, 'gyp')
+  with open(tar_file, 'wb') as f:
+    print("Downloading gyp-next@" + args.tag + " into temporary directory...")
+    print("From: " + tar_url)
+    with urllib.request.urlopen(tar_url) as in_file:
+        f.write(in_file.read())
+
+    print("Unzipping...")
+    with tarfile.open(tar_file, "r:gz") as tar_ref:
+      tar_ref.extractall(unzip_target)
+
+    print("Moving to current checkout (" + CHECKOUT_PATH + ")...")
+    if os.path.exists(CHECKOUT_GYP_PATH):
+      shutil.rmtree(CHECKOUT_GYP_PATH)
+    shutil.move(os.path.join(unzip_target, os.listdir(unzip_target)[0]), CHECKOUT_GYP_PATH)
+
+subprocess.check_output(["git", "add", "gyp"], cwd=CHECKOUT_PATH)
+subprocess.check_output(["git", "commit", "-m", "gyp: update gyp to " + args.tag])