[clang] [LifetimeSafety] Catch intra-method lifetime_capture_by(this) dangles (PR #204630)

[via cfe-commits]

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@@ -858,6 +858,13 @@ void FactsGenerator::handleExitBlock() {
             FactMgr.createFact<GlobalEscapeFact>(O.ID, VD));
       }
     }
+
+  // A borrow captured via [[clang::lifetime_capture_by(this)]] flows into the
+  // never-expiring `this` origin, so it is not otherwise live at the captured
+  // local's expiry. Keep `this` live at exit so the dangle is caught.
+  if (auto ThisOrigins = FactMgr.getOriginMgr().getThisOrigins())
+    EscapesInCurrentBlock.push_back(FactMgr.createFact<ThisEscapeFact>(
+        (*ThisOrigins)->getOuterOriginID(), AC.getDecl()->getEndLoc()));
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NeKon69 wrote:

Ohhh.... Thank you, the naming makes sense now!

https://github.com/llvm/llvm-project/pull/204630