[llvm] [libcxx] [libc++][hardening] Rework macros for enabling the hardening mode. (PR #70575)

[Louis Dionne via llvm-commits]

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@@ -730,14 +727,14 @@ typedef __char32_t char32_t;
 #    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
 #  endif
 
-#  if _LIBCPP_ENABLE_HARDENED_MODE
+#  if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_FAST
 #    define _LIBCPP_HARDENING_SIG h
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ldionne wrote:

We could change those to be in-line with the new names -- there's no need to keep those stable.

https://github.com/llvm/llvm-project/pull/70575