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

[Oliver Hunt via llvm-commits]

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@@ -541,7 +588,33 @@ struct scan_results
 };
 
 }  // unnamed namespace
+} // extern "C"
+
+namespace {
+// The logical model for casting authenticated function pointers makes
+// it impossible to directly cast them without breaking the authentication,
+// as a result we need this pair of helpers.
+template <typename PtrType>
+[[maybe_unused]] void set_landing_pad_as_ptr(scan_results& results, const PtrType& out) {
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ojhunt wrote:

you did not get a warning when not compiling arm64e support? It's possible trunk clang has fixed this?

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