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

tools/clang/scripts/update.py

Index: tools/clang/scripts/update.py
diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
index 3953d672946bb17cc522ae7d2f8eb63d52627682..05dbe71920e10b717878615a57ffa4d3d89291a8 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -450,7 +450,6 @@ def UpdateClang(args):
     return 1
 
   DownloadHostGcc(args)
-  AddSvnToPathOnWin()
   AddCMakeToPath()
   AddGnuWinToPath()
 
@@ -881,6 +880,10 @@ def main():
       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: