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

[Anatoly Trosinenko via llvm-commits]

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@@ -30,6 +30,45 @@ EXCEPTION_DISPOSITION _GCC_specific_handler(PEXCEPTION_RECORD, void *, PCONTEXT,
                                             _Unwind_Personality_Fn);
 #endif
 
+#if __has_feature(ptrauth_qualifier)
+#include <ptrauth.h>
+#if __has_feature(ptrauth_restricted_intptr_qualifier)
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atrosinenko wrote:

I wonder if the expected versions of compilers are explicitly documented somewhere. I glanced through llvm's libunwind docs and found nothing about the expected compilers - whether it should be buildable by the very same version of Clang built from the same commit of the monorepo? any Clang not older `v<major>.<minor>`? recent GCC versions as well? Furthermore, this PR additionally spans compiler-rt builtins, sanitizers and libc++ libraries.

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