[llvm-branch-commits] Add pointer field protection feature. (PR #133538)

[Peter Collingbourne via llvm-branch-commits]

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@@ -7538,6 +7538,14 @@ static bool IsEligibleForTrivialRelocation(Sema &SemaRef,
     if (!SemaRef.IsCXXTriviallyRelocatableType(Field->getType()))
       return false;
   }
+
+  // FIXME: PFP should not affect trivial relocatability, instead it should
+  // affect the implementation of std::trivially_relocate. See:
+  // https://discourse.llvm.org/t/rfc-structure-protection-a-family-of-uaf-mitigation-techniques/85555/16?u=pcc
+  if (!SemaRef.Context.arePFPFieldsTriviallyRelocatable(D) &&
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pcc wrote:

Yes, that does look like the right place for now until we have `std::trivially_relocate` fully implemented. I see there is already a call to `BaseElementType.hasAddressDiscriminatedPointerAuth()` in that function.

https://github.com/llvm/llvm-project/pull/133538