[compiler-rt] TSAN: Report when thread is not live and referenced in pthread (PR #156921)

[Vitaly Buka via llvm-commits]

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@@ -274,6 +274,11 @@ void ThreadRegistry::JoinThread(u32 tid, void *arg) {
     {
       ThreadRegistryLock l(this);
       ThreadContextBase *tctx = threads_[tid];
+
+      if (!tctx) {
+        Report("%s: Tried to join thread %u, but it is not live.", SanitizerToolName, tid);
+      }
+
       CHECK_NE(tctx, 0);
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vitalybuka wrote:

can you move CHECK inside of if(!tctx), just for readablitity
to highlight that they are related

https://github.com/llvm/llvm-project/pull/156921