[libcxx-commits] [libcxx] [libc++] Implements the new FTM header test generator. (PR #134542)

[Louis Dionne via libcxx-commits]

================
@@ -2161,12 +2218,21 @@ class FeatureTestMacros:
 
     # The JSON data structure.
     __data = None
-
-    def __init__(self, filename: str):
+    # The headers not available in libc++.
+    #
+    # This could be detected based on FTM status, however that gives some odd
+    # results. For example, at the moment __cpp_lib_constexpr_cmath is not
+    # implemented, which flags `<cstdlib>` as not implemented. The availablilty
+    # of headers in maintained for the C++ Standard Libarary modules.
----------------
ldionne wrote:

```suggestion
    # implemented, which flags `<cstdlib>` as not implemented. The availability
    # of headers is maintained for the C++ Standard Library modules.
```

https://github.com/llvm/llvm-project/pull/134542