[gn build] Make write_cmake_config.py check that each key passed is unique

I got that wrong once while locally while working on check-llvm.

Reviewed as part of https://reviews.llvm.org/D56195

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350394 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/utils/gn/build/write_cmake_config.py b/utils/gn/build/write_cmake_config.py
index 7fa853d41471ec2cee55d88ba52f03efd756b8f9..0f476542ef6759f6153848fb3c0dddbe08bcbfe4 100755 (executable)
--- a/utils/gn/build/write_cmake_config.py
+++ b/utils/gn/build/write_cmake_config.py
@@ -53,6 +53,9 @@ def main():
     values = {}
     for value in args.values:
         key, val = value.split('=', 1)
+        if key in values:
+            print('duplicate key "%s" in args' % key, file=sys.stderr)
+            return 1
         values[key] = val.replace('\\n', '\n')
     unused_values = set(values.keys())