[compiler-rt] [libcxxabi] [libunwind] [runtimes][PAC] Harden unwinding when possible (#138571) (PR #143230)

[Oliver Hunt via llvm-commits]

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@@ -103,6 +103,52 @@
 #define _LIBCXXABI_DTOR_FUNC
 #endif
 
+#if __has_include(<ptrauth.h>)
+#  include <ptrauth.h>
+#endif
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ojhunt wrote:

So this is something I'm unsure about - there's a lot of checks for the header scattered everywhere but also plenty of places that rely on the feature existing and blindly including the header.

I'm ok putting the ptrauth.h includes unconditionally inside the feature check on the basis that if the header isn't present the ptrauth enabled paths will fail to build

https://github.com/llvm/llvm-project/pull/143230