[Lldb-commits] [lldb] [lldb] Tolerate multiple compile units with the same DWO ID (PR #100577)

[Pavel Labath via lldb-commits]

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@@ -97,12 +97,14 @@ void DWARFUnit::ExtractUnitDIEIfNeeded() {
         *m_dwo_id, m_first_die.GetOffset()));
     return; // Can't fetch the compile unit from the dwo file.
   }
-  // If the skeleton compile unit gets its unit DIE parsed first, then this
-  // will fill in the DWO file's back pointer to this skeleton compile unit.
-  // If the DWO files get parsed on their own first the skeleton back link
-  // can be done manually in DWARFUnit::GetSkeletonCompileUnit() which will
-  // do a reverse lookup and cache the result.
-  dwo_cu->SetSkeletonUnit(this);
+
+  // Link the DWO unit to this object, if it hasn't been linked already (this
+  // can happen when we have an index, and the DWO unit is parsed first).
+  if (!dwo_cu->LinkToSkeletonUnit(*this)) {
+    SetDwoError(Status::createWithFormat(
+        "multiple compile units with Dwo ID {0:x16}", *m_dwo_id));
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labath wrote:

Sounds good. With #100375, I think the only way this can show up is with old compiler versions. New versions should no longer generate identical hashes even in these cases (of course, it's still possible to create a hash collision deliberately, but accidental ones should not be happening).

https://github.com/llvm/llvm-project/pull/100577