[libcxx-commits] [libcxx] [libc++] Fixes lit portability issues. (PR #72435)

[Louis Dionne via libcxx-commits]

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@@ -29,7 +29,13 @@ def appendToSubstitution(substitutions, key, value):
     return [(k, v + " " + value) if k == key else (k, v) for (k, v) in substitutions]
 
 
-std = getSubstitution("%{cxx_std}", config)
+# External users of the LLVM test suite might not have set the substitutions.
+std = ""
+try:
+    std = getSubstitution("%{cxx_std}", config)
+except:
+    pass
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ldionne wrote:

But still, my point is that folks need to be running the test suite via the normal entry points which includes `params.py`, and I don't think it makes sense to try to support anything else. Otherwise we're bound to break them on a regular basis and that's not good for anyone. @StephanTLavavej Are you folks going through our normal entry point for Lit or do you still maintain your own custom Lit test format?

https://github.com/llvm/llvm-project/pull/72435