[libcxx-commits] [libcxx] [libcxxabi] [libc++] Clean up and update deployment target features (PR #96312)

[via libcxx-commits]

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@@ -690,12 +686,12 @@ def check_gdb(cfg):
 # a libc++ flavor that enables availability markup. Similarly, a test could fail when
 # run against the system library of an older version of FreeBSD, even though FreeBSD
 # doesn't provide availability markup at the time of writing this.
-for version in ("11", "12", "13", "14", "15", "16", "17", "18", "19"):
+for version in ("9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19"):
     DEFAULT_FEATURES.append(
         Feature(
             name="using-built-library-before-llvm-{}".format(version),
-            when=lambda cfg: BooleanExpression.evaluate(
-                "stdlib=system && _target-before-llvm-{}".format(version),
+            when=lambda cfg, v=version: BooleanExpression.evaluate(
+                "stdlib=system && !_target-has-llvm-{}".format(v),
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h-vetinari wrote:

I don't know this can work for `using-built-library-before-llvm-{18,19}` (which are being used), since `_target-has-llvm-{18,19}` are undefined. Presumably an unknown quantity is always false? That seems fragile IMO 

https://github.com/llvm/llvm-project/pull/96312