================
@@ -0,0 +1,213 @@
+#include "LifetimeModeling.h"
+#include "clang/AST/Attr.h"
+#include "clang/Analysis/Analyses/LifetimeSafety/LifetimeAnnotations.h"
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace ento;
+
+REGISTER_SET_FACTORY_WITH_PROGRAMSTATE(LifetimeSourceSet, const MemRegion *)
+REGISTER_MAP_WITH_PROGRAMSTATE(LifetimeBoundMap, SVal, LifetimeSourceSet)
+
+namespace {
+
+class LifetimeModeling : public Checker<check::PostCall, check::DeadSymbols> {
+public:
+  void printState(raw_ostream &Out, ProgramStateRef State, const char *NL,
+                  const char *Sep) const override;
+  void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
+  void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
+};
+
+} // namespace
+
+static bool isDanglingStackSource(const MemRegion *Source,
+                                  ProgramStateRef State, CheckerContext &C) {
+  // FIXME: The checker currently handles stack-region sources. Other
+  // region kinds require separate methodology. For example, heap
+  // regions do not go out of scope at the end of a stack frame, so
+  // in order to detect those type of dangling sources the function
+  // needs to be expanded to an event-driven approach as well.
+  if (const auto *StackSpace =
+          Source->getMemorySpaceAs<StackSpaceRegion>(State)) {
+    const StackFrame *SF = StackSpace->getStackFrame();
+    const StackFrame *CurrentSF = C.getStackFrame();
+    if (SF == CurrentSF || !SF->isParentOf(CurrentSF))
+      return true;
+  }
+  return false;
+}
+
+std::vector<const MemRegion *> 
lifetime_modeling::getDanglingRegionsAfterReturn(
+    SVal Val, ProgramStateRef State, CheckerContext &C) {
+  std::vector<const MemRegion *> Regions;
+  if (auto *SourceSet = State->get<LifetimeBoundMap>(Val)) {
+    for (const MemRegion *Region : *SourceSet) {
+      if (isDanglingStackSource(Region, State, C))
+        Regions.push_back(Region);
+    }
+  }
+  return Regions;
+}
+
+static ProgramStateRef bindSource(ProgramStateRef State, SVal RetVal,
+                                  const MemRegion *Source) {
+  LifetimeSourceSet::Factory &F = State->get_context<LifetimeSourceSet>();
+  const LifetimeSourceSet *LSet = State->get<LifetimeBoundMap>(RetVal);
+
+  LifetimeSourceSet Set = LSet ? *LSet : F.getEmptySet();
+  Set = F.add(Set, Source);
+  State = State->set<LifetimeBoundMap>(RetVal, Set);
+  return State;
+}
+
+void LifetimeModeling::checkPostCall(const CallEvent &Call,
+                                     CheckerContext &C) const {
+  ProgramStateRef State = C.getState();
+
+  const auto *FC = dyn_cast<AnyFunctionCall>(&Call);
+  if (!FC)
+    return;
+
+  const FunctionDecl *FD = FC->getDecl();
+  if (!FD)
+    return;
+
+  SVal RetVal = Call.getReturnValue();
+
+  for (const ParmVarDecl *PVD : FD->parameters()) {
+    if (PVD->hasAttr<LifetimeBoundAttr>()) {
+      unsigned Idx = PVD->getFunctionScopeIndex();
+      SVal Arg = Call.getArgSVal(Idx);
+      if (const MemRegion *ArgValRegion = Arg.getAsRegion())
+        State = bindSource(State, RetVal, ArgValRegion);
+    }
+  }
+
+  const auto *IC = dyn_cast<CXXInstanceCall>(&Call);
+  if (IC && lifetimes::implicitObjectParamIsLifetimeBound(FD)) {
+    if (const MemRegion *ThisRegion = IC->getCXXThisVal().getAsRegion())
+      State = bindSource(State, RetVal, ThisRegion);
+  }
+  C.addTransition(State);
+}
+
+void LifetimeModeling::checkDeadSymbols(SymbolReaper &SymReaper,
+                                        CheckerContext &C) const {
+  ProgramStateRef State = C.getState();
+  LifetimeBoundMapTy LBMap = State->get<LifetimeBoundMap>();
+
+  for (SVal Val : llvm::make_first_range(LBMap)) {
+    if (const auto *R = Val.getAsRegion(); R && SymReaper.isLiveRegion(R))
+      continue;
+
+    if (SymbolRef S = Val.getAsSymbol(/*IncludeBaseRegions=*/true);
+        S && SymReaper.isLive(S))
+      continue;
+
+    State = State->remove<LifetimeBoundMap>(Val);
----------------
benedekaibas wrote:

Thank for catching it, forgot to adding it back after the refactor: Done here: 
[3cbe0c7](https://github.com/llvm/llvm-project/pull/205951/commits/3cbe0c7e6ad9ebb387fb2dbf890a57b4d40a58e1)

https://github.com/llvm/llvm-project/pull/205951
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