https://github.com/usx95 updated 
https://github.com/llvm/llvm-project/pull/207520

>From 52d55b077adf8aa69536328ac5f34c058dc794d5 Mon Sep 17 00:00:00 2001
From: Utkarsh Saxena <[email protected]>
Date: Sat, 4 Jul 2026 16:25:06 +0000
Subject: [PATCH] [LifetimeSafety] Support field-sensitivity in lifetime
 tracking

This patch enables field-sensitivity when tracking lifetimes of nested objects.

- FactsGenerator now generates `PathElement::getField` for `MemberExpr` 
accesses, mapping fields to loans.
- LoanPropagation now propagates field paths along flow facts, appending fields 
to base loans.
- Removes false-positive warnings in `invalidations.cpp` where modifications to 
one field were incorrectly reported as invalidating iterators/pointers to 
another field.
- Adds comprehensive unit tests checking nested field access and placeholder 
fields.

TAG=agy
CONV=2cfd8d00-18d7-4a03-8d78-2aba2f9a8f23
---
 .../Analysis/Analyses/LifetimeSafety/Facts.h  |  24 ++++
 .../Analysis/Analyses/LifetimeSafety/Loans.h  |  31 +++++
 clang/lib/Analysis/LifetimeSafety/Dataflow.h  |   8 +-
 clang/lib/Analysis/LifetimeSafety/Facts.cpp   |  24 ++++
 .../LifetimeSafety/FactsGenerator.cpp         |  11 +-
 .../LifetimeSafety/LoanPropagation.cpp        |  84 +++++++++++---
 clang/lib/Analysis/LifetimeSafety/Loans.cpp   |  32 +++++
 .../Sema/LifetimeSafety/invalidations.cpp     |  90 +++++++++++++--
 .../unittests/Analysis/LifetimeSafetyTest.cpp | 109 ++++++++++++------
 9 files changed, 348 insertions(+), 65 deletions(-)

diff --git a/clang/include/clang/Analysis/Analyses/LifetimeSafety/Facts.h 
b/clang/include/clang/Analysis/Analyses/LifetimeSafety/Facts.h
index 8dccccc0f2257..b826e4a979db7 100644
--- a/clang/include/clang/Analysis/Analyses/LifetimeSafety/Facts.h
+++ b/clang/include/clang/Analysis/Analyses/LifetimeSafety/Facts.h
@@ -48,6 +48,11 @@ class Fact {
     /// it. Otherwise, the source's loan set is merged into the destination's
     /// loan set.
     OriginFlow,
+    /// Loans held by the source origin are projected (their access paths are 
extended
+    /// by a path element) and then flowed into the destination origin.
+    /// Example: if `obj` holds loan `{x}`, `p = obj.field` projects `{x}` 
with `field`
+    /// to `{x.field}` and flows it to `p`.
+    Projection,
     /// An origin is used (eg. appears as l-value expression like DeclRefExpr).
     Use,
     /// An origin that is moved (e.g., passed to an rvalue reference 
parameter).
@@ -160,6 +165,25 @@ class OriginFlowFact : public Fact {
             const LoanPropagationAnalysis *LPA = nullptr) const override;
 };
 
+class ProjectionFact : public Fact {
+  OriginID OID;
+  PathElement Element;
+
+public:
+  static bool classof(const Fact *F) {
+    return F->getKind() == Kind::Projection;
+  }
+
+  ProjectionFact(OriginID OID, PathElement Element)
+      : Fact(Kind::Projection), OID(OID), Element(Element) {}
+
+  OriginID getOriginID() const { return OID; }
+  PathElement getPathElement() const { return Element; }
+
+  void dump(llvm::raw_ostream &OS, const LoanManager &, const OriginManager 
&OM,
+            const LoanPropagationAnalysis *LPA = nullptr) const override;
+};
+
 /// Represents that an origin escapes the current scope through various means.
 /// This is the base class for different escape scenarios.
 class OriginEscapesFact : public Fact {
diff --git a/clang/include/clang/Analysis/Analyses/LifetimeSafety/Loans.h 
b/clang/include/clang/Analysis/Analyses/LifetimeSafety/Loans.h
index c20af392a705f..6d512fa4df1ef 100644
--- a/clang/include/clang/Analysis/Analyses/LifetimeSafety/Loans.h
+++ b/clang/include/clang/Analysis/Analyses/LifetimeSafety/Loans.h
@@ -206,6 +206,7 @@ class Loan {
 
 /// Manages the creation, storage and retrieval of loans.
 class LoanManager {
+  using ExtensionCacheKey = std::pair<LoanID, PathElement>;
 
 public:
   LoanManager() = default;
@@ -221,6 +222,17 @@ class LoanManager {
   const PlaceholderBase *getOrCreatePlaceholderBase(const ParmVarDecl *PVD);
   const PlaceholderBase *getOrCreatePlaceholderBase(const CXXMethodDecl *MD);
 
+  /// Gets or creates a loan by extending BaseLoanID with Element.
+  /// Caches the result to ensure convergence in LoanPropagation.
+  Loan *getOrCreateExtendedLoan(LoanID BaseLoanID, PathElement Element);
+
+  /// Finds the base loan IDs that could have been extended to produce
+  /// ExtendedLoanID.
+  llvm::SmallVector<LoanID, 2> getBaseLoans(LoanID ExtendedLoanID,
+                                            PathElement Element) const;
+
+
+
   const Loan *getLoan(LoanID ID) const {
     assert(ID.Value < AllLoans.size());
     return AllLoans[ID.Value];
@@ -234,6 +246,12 @@ class LoanManager {
   LoanID NextLoanID{0};
 
   llvm::FoldingSet<PlaceholderBase> PlaceholderBases;
+  /// Cache for extended loans. Maps (BaseLoanID, PathElement) to the extended
+  /// loan. Ensures that extending the same loan with the same path element
+  /// always returns the same loan object, which is necessary for dataflow
+  /// analysis convergence.
+  llvm::DenseMap<ExtensionCacheKey, Loan *> ExtensionCache;
+
 
   /// TODO(opt): Profile and evaluate the usefullness of small buffer
   /// optimisation.
@@ -242,4 +260,17 @@ class LoanManager {
 };
 } // namespace clang::lifetimes::internal
 
+namespace llvm {
+template <> struct DenseMapInfo<clang::lifetimes::internal::PathElement> {
+  using PathElement = clang::lifetimes::internal::PathElement;
+  static unsigned getHashValue(const PathElement &Val) {
+    return llvm::hash_combine(Val.isInterior(), Val.getFieldDecl());
+  }
+  static bool isEqual(const PathElement &LHS, const PathElement &RHS) {
+    return LHS == RHS;
+  }
+};
+} // namespace llvm
+
+
 #endif // LLVM_CLANG_ANALYSIS_ANALYSES_LIFETIMESAFETY_LOANS_H
diff --git a/clang/lib/Analysis/LifetimeSafety/Dataflow.h 
b/clang/lib/Analysis/LifetimeSafety/Dataflow.h
index fc3049c8bec84..c3a60f9b881f9 100644
--- a/clang/lib/Analysis/LifetimeSafety/Dataflow.h
+++ b/clang/lib/Analysis/LifetimeSafety/Dataflow.h
@@ -60,9 +60,6 @@ class DataflowAnalysis {
   using Base = DataflowAnalysis<Derived, Lattice, Dir>;
 
 private:
-  const CFG &Cfg;
-  AnalysisDeclContext &AC;
-
   /// The dataflow state before a basic block is processed.
   llvm::DenseMap<const CFGBlock *, Lattice> InStates;
   /// The dataflow state after a basic block is processed.
@@ -75,6 +72,8 @@ class DataflowAnalysis {
   static constexpr bool isForward() { return Dir == Direction::Forward; }
 
 protected:
+  const CFG &Cfg;
+  AnalysisDeclContext &AC;
   FactManager &FactMgr;
 
   explicit DataflowAnalysis(const CFG &Cfg, AnalysisDeclContext &AC,
@@ -170,6 +169,8 @@ class DataflowAnalysis {
       return D->transfer(In, *F->getAs<ExpireFact>());
     case Fact::Kind::OriginFlow:
       return D->transfer(In, *F->getAs<OriginFlowFact>());
+    case Fact::Kind::Projection:
+      return D->transfer(In, *F->getAs<ProjectionFact>());
     case Fact::Kind::MovedOrigin:
       return D->transfer(In, *F->getAs<MovedOriginFact>());
     case Fact::Kind::OriginEscapes:
@@ -190,6 +191,7 @@ class DataflowAnalysis {
   Lattice transfer(Lattice In, const IssueFact &) { return In; }
   Lattice transfer(Lattice In, const ExpireFact &) { return In; }
   Lattice transfer(Lattice In, const OriginFlowFact &) { return In; }
+  Lattice transfer(Lattice In, const ProjectionFact &) { return In; }
   Lattice transfer(Lattice In, const MovedOriginFact &) { return In; }
   Lattice transfer(Lattice In, const OriginEscapesFact &) { return In; }
   Lattice transfer(Lattice In, const UseFact &) { return In; }
diff --git a/clang/lib/Analysis/LifetimeSafety/Facts.cpp 
b/clang/lib/Analysis/LifetimeSafety/Facts.cpp
index 15b666fbdf7ca..ffe8bba906ad4 100644
--- a/clang/lib/Analysis/LifetimeSafety/Facts.cpp
+++ b/clang/lib/Analysis/LifetimeSafety/Facts.cpp
@@ -66,6 +66,30 @@ void OriginFlowFact::dump(llvm::raw_ostream &OS, const 
LoanManager &LM,
   OS << "\n";
 }
 
+void ProjectionFact::dump(llvm::raw_ostream &OS, const LoanManager &LM,
+                          const OriginManager &OM,
+                          const LoanPropagationAnalysis *LPA) const {
+  OS << "Projection: \n";
+  OS << "\tOrigin: ";
+  OM.dump(getOriginID(), OS);
+  if (LPA) {
+    LoanSet Loans = LPA->getLoans(getOriginID(), this);
+    if (Loans.isEmpty())
+      OS << " has no loans";
+    else {
+      OS << " has loans to { ";
+      for (LoanID LID : Loans) {
+        LM.getLoan(LID)->getAccessPath().dump(OS);
+        OS << " ";
+      }
+      OS << "}";
+    }
+  }
+  OS << "\n\tElement: ";
+  getPathElement().dump(OS);
+  OS << "\n";
+}
+
 void MovedOriginFact::dump(llvm::raw_ostream &OS, const LoanManager &,
                            const OriginManager &OM,
                            const LoanPropagationAnalysis *) const {
diff --git a/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp 
b/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp
index 95872d32adfb6..d07e7857b209a 100644
--- a/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp
+++ b/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp
@@ -274,17 +274,18 @@ void FactsGenerator::VisitCXXMemberCallExpr(const 
CXXMemberCallExpr *MCE) {
 
 void FactsGenerator::VisitMemberExpr(const MemberExpr *ME) {
   auto *MD = ME->getMemberDecl();
-  if (isa<FieldDecl>(MD) && doesDeclHaveStorage(MD)) {
+  if (auto *FD = dyn_cast<FieldDecl>(MD); FD && doesDeclHaveStorage(FD)) {
     assert(ME->isGLValue() && "Field member should be GL value");
     OriginList *Dst = getOriginsList(*ME);
     assert(Dst && "Field member should have an origin list as it is GL value");
     OriginList *Src = getOriginsList(*ME->getBase());
     assert(Src && "Base expression should be a pointer/reference type");
-    // The field's glvalue (outermost origin) holds the same loans as the base
-    // expression.
+    // Flow loans from base to field, extending each loan's path with the 
field.
+    // E.g., if base has loan to `obj`, field gets loan to `obj.field`.
     CurrentBlockFacts.push_back(FactMgr.createFact<OriginFlowFact>(
-        Dst->getOuterOriginID(), Src->getOuterOriginID(),
-        /*Kill=*/true));
+        Dst->getOuterOriginID(), Src->getOuterOriginID(), /*KillDest=*/true));
+    CurrentBlockFacts.push_back(FactMgr.createFact<ProjectionFact>(
+        Dst->getOuterOriginID(), PathElement::getField(FD)));
   }
 }
 
diff --git a/clang/lib/Analysis/LifetimeSafety/LoanPropagation.cpp 
b/clang/lib/Analysis/LifetimeSafety/LoanPropagation.cpp
index a67b1b3c0f826..65492625c3027 100644
--- a/clang/lib/Analysis/LifetimeSafety/LoanPropagation.cpp
+++ b/clang/lib/Analysis/LifetimeSafety/LoanPropagation.cpp
@@ -58,6 +58,11 @@ static llvm::BitVector computePersistentOrigins(const 
FactManager &FactMgr,
         CheckOrigin(OF->getSrcOriginID());
         break;
       }
+      case Fact::Kind::Projection: {
+        const auto *PF = F->getAs<ProjectionFact>();
+        CheckOrigin(PF->getOriginID());
+        break;
+      }
       case Fact::Kind::Use:
         for (const OriginList *Cur = F->getAs<UseFact>()->getUsedOrigins(); 
Cur;
              Cur = Cur->peelOuterOrigin())
@@ -180,14 +185,28 @@ class AnalysisImpl
     OriginID DestOID = F.getDestOriginID();
     OriginID SrcOID = F.getSrcOriginID();
 
+    LoanSet SrcLoans = getLoans(In, SrcOID);
     LoanSet DestLoans =
         F.getKillDest() ? LoanSetFactory.getEmptySet() : getLoans(In, DestOID);
-    LoanSet SrcLoans = getLoans(In, SrcOID);
     LoanSet MergedLoans = utils::join(DestLoans, SrcLoans, LoanSetFactory);
 
     return setLoans(In, DestOID, MergedLoans);
   }
 
+  /// A projection projects the loans currently held by the origin in-place.
+  Lattice transfer(Lattice In, const ProjectionFact &F) {
+    OriginID OID = F.getOriginID();
+    LoanSet Loans = getLoans(In, OID);
+    LoanSet ProjectedLoans = LoanSetFactory.getEmptySet();
+    PathElement Element = F.getPathElement();
+    for (LoanID LID : Loans) {
+      Loan *ExtendedLoan =
+          FactMgr.getLoanMgr().getOrCreateExtendedLoan(LID, Element);
+      ProjectedLoans = LoanSetFactory.add(ProjectedLoans, 
ExtendedLoan->getID());
+    }
+    return setLoans(In, OID, ProjectedLoans);
+  }
+
   Lattice transfer(Lattice In, const KillOriginFact &F) {
     return setLoans(In, F.getKilledOrigin(), LoanSetFactory.getEmptySet());
   }
@@ -208,31 +227,68 @@ class AnalysisImpl
     assert(getLoans(StartOID, StartPoint).contains(TargetLoan) &&
            "TargetLoan must be present in the StartOID at the StartPoint");
 
+    LoanID CurrLoanID = TargetLoan;
     OriginID CurrOID = StartOID;
     llvm::SmallVector<OriginID> OriginFlowChain;
     llvm::ArrayRef<const Fact *> Facts = 
FactMgr.getBlockContaining(StartPoint);
     const auto *StartIt = llvm::find(Facts, StartPoint);
     assert(StartIt != Facts.end());
 
+    const CFGBlock *B = nullptr;
+    for (const CFGBlock *Block : Cfg) {
+      if (FactMgr.getFacts(Block).data() == Facts.data()) {
+        B = Block;
+        break;
+      }
+    }
+    assert(B && "Could not find CFGBlock containing StartPoint");
+
+    auto GetStateBefore = [&](const Fact *F) -> Lattice {
+      auto It = llvm::find(Facts, F);
+      assert(It != Facts.end());
+      if (It == Facts.begin()) {
+        auto InState = getInState(B);
+        assert(InState);
+        return *InState;
+      }
+      return getState(*(It - 1));
+    };
+
     for (const Fact *F :
          llvm::reverse(llvm::make_range(Facts.begin(), StartIt))) {
-      if (const auto *IF = F->getAs<IssueFact>())
-        if (IF->getLoanID() == TargetLoan) {
+      if (const auto *IF = F->getAs<IssueFact>()) {
+        if (IF->getLoanID() == CurrLoanID) {
           assert(IF->getOriginID() == CurrOID);
           return OriginFlowChain;
         }
+      }
 
-      const auto *OFF = F->getAs<OriginFlowFact>();
-      if (!OFF)
-        continue;
-      if (OFF->getDestOriginID() != CurrOID)
-        continue;
-
-      const OriginID SrcOriginID = OFF->getSrcOriginID();
-      if (!getLoans(SrcOriginID, OFF).contains(TargetLoan))
-        continue;
-      OriginFlowChain.push_back(SrcOriginID);
-      CurrOID = SrcOriginID;
+      if (const auto *OFF = F->getAs<OriginFlowFact>()) {
+        if (OFF->getDestOriginID() == CurrOID) {
+          OriginID SrcOriginID = OFF->getSrcOriginID();
+          if (getLoans(SrcOriginID, OFF).contains(CurrLoanID)) {
+            CurrOID = SrcOriginID;
+            OriginFlowChain.push_back(SrcOriginID);
+          }
+        }
+      } else if (const auto *PF = F->getAs<ProjectionFact>()) {
+        if (PF->getOriginID() == CurrOID) {
+          PathElement Element = PF->getPathElement();
+          auto Candidates =
+              FactMgr.getLoanMgr().getBaseLoans(CurrLoanID, Element);
+          std::optional<LoanID> NextLoanID;
+          Lattice StateBefore = GetStateBefore(PF);
+          for (LoanID Candidate : Candidates) {
+            if (getLoans(StateBefore, CurrOID).contains(Candidate)) {
+              NextLoanID = Candidate;
+              break;
+            }
+          }
+          if (NextLoanID) {
+            CurrLoanID = *NextLoanID;
+          }
+        }
+      }
     }
 
     // FIXME: Ideally, this return is unreachable and should be an assert
diff --git a/clang/lib/Analysis/LifetimeSafety/Loans.cpp 
b/clang/lib/Analysis/LifetimeSafety/Loans.cpp
index 3c90ed85831ca..9692b5ff33f48 100644
--- a/clang/lib/Analysis/LifetimeSafety/Loans.cpp
+++ b/clang/lib/Analysis/LifetimeSafety/Loans.cpp
@@ -64,4 +64,36 @@ LoanManager::getOrCreatePlaceholderBase(const CXXMethodDecl 
*MD) {
   PlaceholderBases.InsertNode(NewPB, InsertPos);
   return NewPB;
 }
+
+Loan *LoanManager::getOrCreateExtendedLoan(LoanID BaseLoanID,
+                                           PathElement Element) {
+
+  ExtensionCacheKey Key = {BaseLoanID, Element};
+  auto It = ExtensionCache.find(Key);
+  if (It != ExtensionCache.end())
+    return It->second;
+  const auto *BaseLoan = getLoan(BaseLoanID);
+  // TODO: Polish comment: Do not add interior access if the base loan path
+  // already contains that at the end.
+  if (Element.isInterior() &&
+      !BaseLoan->getAccessPath().getElements().empty() &&
+      BaseLoan->getAccessPath().getElements().back().isInterior())
+    return ExtensionCache[Key] = const_cast<Loan *>(BaseLoan);
+
+  AccessPath ExtendedPath(BaseLoan->getAccessPath(), Element);
+  return ExtensionCache[Key] =
+             createLoan(ExtendedPath, BaseLoan->getIssueExpr());
+}
+
+llvm::SmallVector<LoanID, 2>
+LoanManager::getBaseLoans(LoanID ExtendedLoanID, PathElement Element) const {
+  llvm::SmallVector<LoanID, 2> Result;
+  for (const auto &Entry : ExtensionCache) {
+    if (Entry.second->getID() == ExtendedLoanID &&
+        Entry.first.second == Element) {
+      Result.push_back(Entry.first.first);
+    }
+  }
+  return Result;
+}
 } // namespace clang::lifetimes::internal
diff --git a/clang/test/Sema/LifetimeSafety/invalidations.cpp 
b/clang/test/Sema/LifetimeSafety/invalidations.cpp
index be1acc6bc7fbc..1572e78a27e14 100644
--- a/clang/test/Sema/LifetimeSafety/invalidations.cpp
+++ b/clang/test/Sema/LifetimeSafety/invalidations.cpp
@@ -485,13 +485,12 @@ void ConditionalFieldInvalidatesIterator(bool flag) {
     (flag ? s.strings1 : s.strings2).push_back("1");
     *it;
 }
-// FIXME: Requires field-sensitive AccessPaths to fix.
 void Invalidate1Use2ViaRefIsOk() {
     S s;
-    auto it = s.strings2.begin(); // expected-warning {{local variable 's' is 
later invalidated}}
+    auto it = s.strings2.begin();
     auto& strings1 = s.strings1;
-    strings1.push_back("1");      // expected-note {{local variable 's' is 
invalidated here}}
-    *it;                          // expected-note {{later used here}}
+    strings1.push_back("1");      // OK
+    *it;
 }
 void Invalidate1UseSIsOk() {
   S s;
@@ -894,12 +893,11 @@ struct StringOwner {
   std::string s, t;
 };
 
-// FIXME: False-positive
 void member_destructor_invalidates_pointer() {
   StringOwner owner = {"42", "43"};
-  const char *p = owner.s.data(); // expected-warning {{local variable 'owner' 
is later invalidated}}
-  owner.t.~basic_string();        // expected-note {{local variable 'owner' is 
invalidated here}}
-  (void)*p;                       // expected-note {{later used here}}
+  const char *p = owner.s.data();
+  owner.t.~basic_string();        // OK
+  (void)*p;
 }
 
 } // namespace explicit_destructor
@@ -937,3 +935,79 @@ void invalid_after_ternary_reset(bool flag) {
 }
 
 } // namespace unique_ptr_invalidation
+
+namespace DeepFieldNesting {
+struct Level3 {
+  std::vector<std::string> vec;
+  int x;
+};
+struct Level2 {
+  Level3 inner3_1;
+  Level3 inner3_2;
+};
+struct Level1 {
+  Level2 inner2_1;
+  Level2 inner2_2;
+};
+
+// Modifying sibling at Level 3: OK
+void SiblingLevel3Ok() {
+  Level1 obj;
+  auto it = obj.inner2_1.inner3_1.vec.begin();
+  obj.inner2_1.inner3_2.vec.push_back("1"); 
+  *it; 
+}
+
+// Modifying sibling at Level 2: OK
+void SiblingLevel2Ok() {
+  Level1 obj;
+  auto it = obj.inner2_1.inner3_1.vec.begin();
+  obj.inner2_2.inner3_1.vec.push_back("1");
+  *it;
+}
+
+// Modifying sibling non-container field at Level 3: OK
+void SiblingFieldLevel3Ok() {
+  Level1 obj;
+  auto it = obj.inner2_1.inner3_1.vec.begin();
+  obj.inner2_1.inner3_1.x = 42;
+  *it;
+}
+
+// Modifying parent structure after use: OK
+void ParentModifiedAfterUseOk() {
+  Level1 obj;
+  auto it = obj.inner2_1.inner3_1.vec.begin();
+  *it; // Use here
+  Level3 new_val;
+  obj.inner2_1.inner3_1 = new_val; // OK, because 'it' is no longer used!
+}
+
+// Pointers with sibling modification: OK
+void PointerSiblingLevel3Ok(Level1* ptr) {
+  auto it = ptr->inner2_1.inner3_1.vec.begin();
+  ptr->inner2_1.inner3_2.vec.push_back("1"); // OK
+  *it;
+}
+
+// References with sibling modification: OK
+void ReferenceSiblingLevel3Ok(Level1& ref) {
+  auto it = ref.inner2_1.inner3_1.vec.begin();
+  ref.inner2_1.inner3_2.vec.push_back("1"); // OK
+  *it;
+}
+} // namespace DeepFieldNesting
+
+namespace StructFieldDisambiguation {
+struct S {
+  std::vector<int> v;
+  int x;
+};
+
+void TestStructVsField(S& s) {
+  int* px = &s.x;
+  s.v.push_back(1); // Invalidates s.v.* (interior), but must NOT invalidate 
s.x
+  *px = 42;         // OK
+}
+} // namespace StructFieldDisambiguation
+
diff --git a/clang/unittests/Analysis/LifetimeSafetyTest.cpp 
b/clang/unittests/Analysis/LifetimeSafetyTest.cpp
index 78b7449958140..e13b8f88cb834 100644
--- a/clang/unittests/Analysis/LifetimeSafetyTest.cpp
+++ b/clang/unittests/Analysis/LifetimeSafetyTest.cpp
@@ -12,6 +12,7 @@
 #include "clang/Analysis/Analyses/LifetimeSafety/Loans.h"
 #include "clang/Testing/TestAST.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/Support/raw_ostream.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include <optional>
@@ -136,11 +137,16 @@ class LifetimeTestHelper {
   }
 
   bool isLoanToATemporary(LoanID LID) {
-    return Analysis.getFactManager()
-               .getLoanMgr()
-               .getLoan(LID)
-               ->getAccessPath()
-               .getAsMaterializeTemporaryExpr() != nullptr;
+    const Loan *L = Analysis.getFactManager().getLoanMgr().getLoan(LID);
+    return L->getAccessPath().getAsMaterializeTemporaryExpr() != nullptr;
+  }
+
+  std::string getAccessPathString(LoanID LID) {
+    const Loan *L = Analysis.getFactManager().getLoanMgr().getLoan(LID);
+    std::string S;
+    llvm::raw_string_ostream OS(S);
+    L->getAccessPath().dump(OS);
+    return S;
   }
 
   // Gets the set of loans that are live at the given program point. A loan is
@@ -287,7 +293,7 @@ class OriginsInfo {
 /// variable expected to be the source of a loan.
 /// \param Annotation A string identifying the program point (created with
 /// POINT()) where the check should be performed.
-MATCHER_P2(HasLoansToImpl, LoanVars, Annotation, "") {
+MATCHER_P2(HasLoansToImpl, LoanPathStrs, Annotation, "") {
   const OriginInfo &Info = arg;
   std::optional<OriginID> OIDOpt = 
Info.Helper.getOriginForDecl(Info.OriginVar);
   if (!OIDOpt) {
@@ -303,36 +309,12 @@ MATCHER_P2(HasLoansToImpl, LoanVars, Annotation, "") {
                      << Annotation << "'";
     return false;
   }
-  std::vector<LoanID> ActualLoans(ActualLoansSetOpt->begin(),
-                                  ActualLoansSetOpt->end());
-
-  std::vector<LoanID> ExpectedLoans;
-  for (const auto &LoanVar : LoanVars) {
-    std::vector<LoanID> ExpectedLIDs = Info.Helper.getLoansForVar(LoanVar);
-    if (ExpectedLIDs.empty()) {
-      *result_listener << "could not find loan for var '" << LoanVar << "'";
-      return false;
-    }
-    ExpectedLoans.insert(ExpectedLoans.end(), ExpectedLIDs.begin(),
-                         ExpectedLIDs.end());
-  }
-  std::sort(ExpectedLoans.begin(), ExpectedLoans.end());
-  std::sort(ActualLoans.begin(), ActualLoans.end());
-  if (ExpectedLoans != ActualLoans) {
-    *result_listener << "Expected: {";
-    for (const auto &LoanID : ExpectedLoans) {
-      *result_listener << LoanID.Value << ", ";
-    }
-    *result_listener << "} Actual: {";
-    for (const auto &LoanID : ActualLoans) {
-      *result_listener << LoanID.Value << ", ";
-    }
-    *result_listener << "}";
-    return false;
-  }
+  std::vector<std::string> ActualLoanPaths;
+  for (LoanID LID : *ActualLoansSetOpt)
+    ActualLoanPaths.push_back(Info.Helper.getAccessPathString(LID));
 
-  return ExplainMatchResult(UnorderedElementsAreArray(ExpectedLoans),
-                            ActualLoans, result_listener);
+  return ExplainMatchResult(UnorderedElementsAreArray(LoanPathStrs),
+                            ActualLoanPaths, result_listener);
 }
 
 enum class LivenessKindFilter { Maybe, Must, All };
@@ -1213,6 +1195,63 @@ TEST_F(LifetimeAnalysisTest, 
LifetimeboundConversionOperator) {
   EXPECT_THAT(Origin("v"), HasLoansTo({"owner"}, "p1"));
 }
 
+TEST_F(LifetimeAnalysisTest, NestedFieldAccess) {
+  SetupTest(R"(
+    struct Inner { int val; };
+    struct Outer { Inner f; };
+    void target() {
+        Outer o;
+        Outer *p = &o;
+        int* p1 = &o.f.val;
+        POINT(a);
+        int* p2 = &p->f.val;
+        POINT(b);
+    }
+  )");
+  EXPECT_THAT(Origin("p1"), HasLoansTo({"o.f.val"}, "a"));
+  EXPECT_THAT(Origin("p2"), HasLoansTo({"o.f.val"}, "b"));
+}
+
+TEST_F(LifetimeAnalysisTest, PlaceholderParamField) {
+  SetupTest(R"(
+    struct S { int val; };
+    void target(S* p) {
+      int* p1 = &p->val;
+      POINT(a);
+    }
+  )");
+  EXPECT_THAT(Origin("p1"), HasLoansTo({"$p.val"}, "a"));
+}
+
+TEST_F(LifetimeAnalysisTest, PlaceholderThisField) {
+  SetupTest(R"(
+    struct S {
+      int f;
+      void target() {
+        int* p1 = &f;
+        POINT(a);
+      }
+    };
+  )");
+  EXPECT_THAT(Origin("p1"), HasLoansTo({"$this.f"}, "a"));
+}
+
+TEST_F(LifetimeAnalysisTest, PlaceholderThisNestedField) {
+  SetupTest(R"(
+    struct S1 {
+      int f;
+    };
+    struct S {
+      S1 s1;
+      void target() {
+        int* p1 = &s1.f;
+        POINT(a);
+      }
+    };
+  )");
+  EXPECT_THAT(Origin("p1"), HasLoansTo({"$this.s1.f"}, "a"));
+}
+
 TEST_F(LifetimeAnalysisTest, LivenessDeadPointer) {
   SetupTest(R"(
     void target() {

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