Check for SVN earlier in clang's update.py script

tools/clang/scripts/update.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """This script is used to download prebuilt clang binaries.
 
 It is also used by package.py to build the prebuilt clang binaries."""
 
 import argparse
@@ skipping 432 matching lines @@
 
   if args.with_android and not os.path.exists(ANDROID_NDK_DIR):
     print 'Android NDK not found at ' + ANDROID_NDK_DIR
     print 'The Android NDK is needed to build a Clang whose -fsanitize=address'
     print 'works on Android. See '
     print 'https://www.chromium.org/developers/how-tos/android-build-instructions'
     print 'for how to install the NDK, or pass --without-android.'
     return 1
 
   DownloadHostGcc(args)
-  AddSvnToPathOnWin()
   AddCMakeToPath()
   AddGnuWinToPath()
 
   DeleteChromeToolsShim()
 
   Checkout('LLVM', LLVM_REPO_URL + '/llvm/trunk', LLVM_DIR)
   Checkout('Clang', LLVM_REPO_URL + '/cfe/trunk', CLANG_DIR)
   if sys.platform != 'darwin':
     Checkout('LLD', LLVM_REPO_URL + '/lld/trunk', LLD_DIR)
   elif os.path.exists(LLD_DIR):
@@ skipping 410 matching lines @@
   if args.lto_gold_plugin and not sys.platform.startswith('linux'):
     print '--lto-gold-plugin is only effective on Linux. Ignoring the option.'
     args.lto_gold_plugin = False
 
   if args.if_needed:
     # TODO(thakis): Can probably remove this and --if-needed altogether.
     if re.search(r'\b(make_clang_dir)=', os.environ.get('GYP_DEFINES', '')):
       print 'Skipping Clang update (make_clang_dir= was set in GYP_DEFINES).'
       return 0
 
+  if (use_head_revision or args.llvm_force_head_revision or

[Reid Kleckner, 2017/03/29 22:10:57]

Do we need both the LLVM_USE_HEAD_REVISION environment variable and the
--llvm-force-head-revision flag?

[Nico, 2017/03/29 23:16:41]

Yes :-( This runs as a hook on bots, and there's no good way to conditionally
pass flags from DEPS. So we need the env var. And requiring people to set env
vars is criminal, so we need the flag. But the implementation should probably be
"if env var set, set flag" and the only look at the flag everywhere else. (Maybe
argparse even has some env reading thing).

+      args.force_local_build):
+    AddSvnToPathOnWin()
+
   global CLANG_REVISION, PACKAGE_VERSION
   if args.print_revision:
     if use_head_revision or args.llvm_force_head_revision:
       print GetSvnRevision(LLVM_DIR)
     else:
       print PACKAGE_VERSION
     return 0
 
   if args.print_clang_version:
     sys.stdout.write(VERSION)
@@ skipping 13 matching lines @@
     args.force_local_build = True
     if 'OS=android' not in os.environ.get('GYP_DEFINES', ''):
       # Only build the Android ASan rt on ToT bots when targetting Android.
       args.with_android = False
 
   return UpdateClang(args)
 
 
 if __name__ == '__main__':
   sys.exit(main())