[build system] If there's an OVERRIDE, don't guess the current SCM.

This makes automatic checkout work even in situations where the
current repository can't be determined, such as in the case of a 
Git tag.

llvm-svn: 306460

1 files changed, 3 insertions, 0 deletions

diff --git a/lldb/scripts/Xcode/build-llvm.py b/lldb/scripts/Xcode/build-llvm.py
index 36e491ebf06..e2a46de1a16 100755
--- a/lldb/scripts/Xcode/build-llvm.py
+++ b/lldb/scripts/Xcode/build-llvm.py
@@ -43,6 +43,9 @@ def process_repo(r):
     }
 
 def XCODE_REPOSITORIES():
+    override = repo.get_override()
+    if override:
+        return [process_repo(r) for r in override]
     identifier = repo.identifier()
     if identifier == None:
         identifier = "<invalid>" # repo.find will just use the fallback file