uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/development/compilers/llvm/update-git.py

@@ -0,0 +1,92 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i python3 -p python3 nix
+
+import csv
+import fileinput
+import json
+import os
+import re
+import subprocess
+import sys
+
+from codecs import iterdecode
+from datetime import datetime
+from urllib.request import urlopen, Request
+
+
+DEFAULT_NIX = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'git/default.nix')
+
+
+def get_latest_chromium_build():
+    HISTORY_URL = 'https://omahaproxy.appspot.com/history?os=linux'
+    print(f'GET {HISTORY_URL}')
+    with urlopen(HISTORY_URL) as resp:
+        builds = csv.DictReader(iterdecode(resp, 'utf-8'))
+        for build in builds:
+            if build['channel'] != 'dev':
+                continue
+            return build
+
+
+def get_file_revision(revision, file_path):
+    """Fetches the requested Git revision of the given Chromium file."""
+    url = f'https://raw.githubusercontent.com/chromium/chromium/{revision}/{file_path}'
+    with urlopen(url) as http_response:
+        return http_response.read().decode()
+
+
+def get_commit(ref):
+    url = f'https://api.github.com/repos/llvm/llvm-project/commits/{ref}'
+    headers = {'Accept': 'application/vnd.github.v3+json'}
+    request = Request(url, headers=headers)
+    with urlopen(request) as http_response:
+        return json.loads(http_response.read().decode())
+
+
+def get_current_revision():
+    """Get the current revision of llvmPackages_git."""
+    with open(DEFAULT_NIX) as f:
+        for line in f:
+            rev = re.search(r'^  rev = "(.*)";', line)
+            if rev:
+                return rev.group(1)
+    sys.exit(1)
+
+
+def nix_prefetch_url(url, algo='sha256'):
+    """Prefetches the content of the given URL."""
+    print(f'nix-prefetch-url {url}')
+    out = subprocess.check_output(['nix-prefetch-url', '--type', algo, '--unpack', url])
+    return out.decode('utf-8').rstrip()
+
+
+chromium_build = get_latest_chromium_build()
+chromium_version = chromium_build['version']
+print(f'chromiumDev version: {chromium_version}')
+print('Getting LLVM commit...')
+clang_update_script = get_file_revision(chromium_version, 'tools/clang/scripts/update.py')
+clang_revision = re.search(r"^CLANG_REVISION = '(.+)'$", clang_update_script, re.MULTILINE).group(1)
+clang_commit_short = re.search(r"llvmorg-[0-9]+-init-[0-9]+-g([0-9a-f]{8})", clang_revision).group(1)
+release_version = re.search(r"^RELEASE_VERSION = '(.+)'$", clang_update_script, re.MULTILINE).group(1)
+commit = get_commit(clang_commit_short)
+if get_current_revision() == commit["sha"]:
+    print('No new update available.')
+    sys.exit(0)
+date = datetime.fromisoformat(commit['commit']['committer']['date'].rstrip('Z')).date().isoformat()
+version = f'unstable-{date}'
+print('Prefetching source tarball...')
+hash = nix_prefetch_url(f'https://github.com/llvm/llvm-project/archive/{commit["sha"]}.tar.gz')
+print('Updating default.nix...')
+with fileinput.FileInput(DEFAULT_NIX, inplace=True) as f:
+    for line in f:
+        if match := re.search(r'^  rev-version = "unstable-(.+)";', line):
+                old_date = match.group(1)
+        result = re.sub(r'^  release_version = ".+";', f'  release_version = "{release_version}";', line)
+        result = re.sub(r'^  rev = ".*";', f'  rev = "{commit["sha"]}";', result)
+        result = re.sub(r'^  rev-version = ".+";', f'  rev-version = "{version}";', result)
+        result = re.sub(r'^    sha256 = ".+";', f'    sha256 = "{hash}";', result)
+        print(result, end='')
+# Commit the result:
+commit_message = f"llvmPackages_git: {old_date} -> {date}"
+subprocess.run(['git', 'add', DEFAULT_NIX], check=True)
+subprocess.run(['git', 'commit', '--file=-'], input=commit_message.encode(), check=True)