[compiler-rt] [TySan] Fix false positives with derived classes (PR #126260)

[via llvm-commits]

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@@ -102,20 +102,8 @@ static tysan_type_descriptor *getRootTD(tysan_type_descriptor *TD) {
   return RootTD;
 }
 
-static bool isAliasingLegalUp(tysan_type_descriptor *TDA,
-                              tysan_type_descriptor *TDB, int TDAOffset) {
-  // Walk up the tree starting with TDA to see if we reach TDB.
-  uptr OffsetA = 0, OffsetB = 0;
-  if (TDB->Tag == TYSAN_MEMBER_TD) {
-    OffsetB = TDB->Member.Offset;
-    TDB = TDB->Member.Base;
-  }
-
-  if (TDA->Tag == TYSAN_MEMBER_TD) {
-    OffsetA = TDA->Member.Offset - TDAOffset;
-    TDA = TDA->Member.Base;
-  }
-
+bool walkAliasTree(tysan_type_descriptor *TDA, tysan_type_descriptor *TDB,
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gbMattN wrote:

Ah, was too liberal in my git reset --hard's I think 😅

https://github.com/llvm/llvm-project/pull/126260