Index: include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
===================================================================
--- include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
+++ include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
@@ -198,9 +198,11 @@
   DefinedOrUnknownSVal getDerivedRegionValueSymbolVal(
       SymbolRef parentSymbol, const TypedValueRegion *region);
 
-  DefinedSVal getMetadataSymbolVal(
-      const void *symbolTag, const MemRegion *region,
-      const Expr *expr, QualType type, unsigned count);
+  DefinedSVal getMetadataSymbolVal(const void *symbolTag,
+                                   const MemRegion *region,
+                                   const Expr *expr, QualType type,
+                                   const LocationContext *LCtx,
+                                   unsigned count);
 
   DefinedSVal getFunctionPointer(const FunctionDecl *func);
   
Index: include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
===================================================================
--- include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
+++ include/clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h
@@ -184,15 +184,18 @@
   const MemRegion* R;
   const Stmt *S;
   QualType T;
+  const LocationContext *LCtx;
   unsigned Count;
   const void *Tag;
 public:
   SymbolMetadata(SymbolID sym, const MemRegion* r, const Stmt *s, QualType t,
-                 unsigned count, const void *tag)
-  : SymbolData(SymbolMetadataKind, sym), R(r), S(s), T(t), Count(count), Tag(tag) {}
+                 const LocationContext *LCtx, unsigned count, const void *tag)
+  : SymbolData(SymbolMetadataKind, sym), R(r), S(s), T(t), LCtx(LCtx),
+    Count(count), Tag(tag) {}
 
   const MemRegion *getRegion() const { return R; }
   const Stmt *getStmt() const { return S; }
+  const LocationContext *getLocationContext() const { return LCtx; }
   unsigned getCount() const { return Count; }
   const void *getTag() const { return Tag; }
 
@@ -201,18 +204,19 @@
   void dumpToStream(raw_ostream &os) const override;
 
   static void Profile(llvm::FoldingSetNodeID& profile, const MemRegion *R,
-                      const Stmt *S, QualType T, unsigned Count,
-                      const void *Tag) {
+                      const Stmt *S, QualType T, const LocationContext *LCtx,
+                      unsigned Count, const void *Tag) {
     profile.AddInteger((unsigned) SymbolMetadataKind);
     profile.AddPointer(R);
     profile.AddPointer(S);
     profile.Add(T);
+    profile.AddPointer(LCtx);
     profile.AddInteger(Count);
     profile.AddPointer(Tag);
   }
 
   void Profile(llvm::FoldingSetNodeID& profile) override {
-    Profile(profile, R, S, T, Count, Tag);
+    Profile(profile, R, S, T, LCtx, Count, Tag);
   }
 
   // Implement isa<T> support.
@@ -433,7 +437,9 @@
   /// VisitCount can be used to differentiate regions corresponding to
   /// different loop iterations, thus, making the symbol path-dependent.
   const SymbolMetadata *getMetadataSymbol(const MemRegion *R, const Stmt *S,
-                                          QualType T, unsigned VisitCount,
+                                          QualType T,
+                                          const LocationContext *LCtx,
+                                          unsigned VisitCount,
                                           const void *SymbolTag = nullptr);
 
   const SymbolCast* getCastSymbol(const SymExpr *Operand,
Index: lib/StaticAnalyzer/Checkers/CStringChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -686,6 +686,7 @@
   QualType sizeTy = svalBuilder.getContext().getSizeType();
   SVal strLength = svalBuilder.getMetadataSymbolVal(CStringChecker::getTag(),
                                                     MR, Ex, sizeTy,
+                                                    C.getLocationContext(),
                                                     C.blockCount());
 
   if (!hypothetical) {
Index: lib/StaticAnalyzer/Core/SValBuilder.cpp
===================================================================
--- lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ lib/StaticAnalyzer/Core/SValBuilder.cpp
@@ -182,11 +182,12 @@
 DefinedSVal SValBuilder::getMetadataSymbolVal(const void *symbolTag,
                                               const MemRegion *region,
                                               const Expr *expr, QualType type,
+                                              const LocationContext *LCtx,
                                               unsigned count) {
   assert(SymbolManager::canSymbolicate(type) && "Invalid metadata symbol type");
 
   SymbolRef sym =
-      SymMgr.getMetadataSymbol(region, expr, type, count, symbolTag);
+      SymMgr.getMetadataSymbol(region, expr, type, LCtx, count, symbolTag);
 
   if (Loc::isLocType(type))
     return loc::MemRegionVal(MemMgr.getSymbolicRegion(sym));
Index: lib/StaticAnalyzer/Core/SymbolManager.cpp
===================================================================
--- lib/StaticAnalyzer/Core/SymbolManager.cpp
+++ lib/StaticAnalyzer/Core/SymbolManager.cpp
@@ -216,17 +216,18 @@
   return cast<SymbolExtent>(SD);
 }
 
-const SymbolMetadata*
+const SymbolMetadata *
 SymbolManager::getMetadataSymbol(const MemRegion* R, const Stmt *S, QualType T,
+                                 const LocationContext *LCtx,
                                  unsigned Count, const void *SymbolTag) {
 
   llvm::FoldingSetNodeID profile;
-  SymbolMetadata::Profile(profile, R, S, T, Count, SymbolTag);
+  SymbolMetadata::Profile(profile, R, S, T, LCtx, Count, SymbolTag);
   void *InsertPos;
   SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
   if (!SD) {
     SD = (SymExpr*) BPAlloc.Allocate<SymbolMetadata>();
-    new (SD) SymbolMetadata(SymbolCounter, R, S, T, Count, SymbolTag);
+    new (SD) SymbolMetadata(SymbolCounter, R, S, T, LCtx, Count, SymbolTag);
     DataSet.InsertNode(SD, InsertPos);
     ++SymbolCounter;
   }
Index: test/Analysis/string.c
===================================================================
--- test/Analysis/string.c
+++ test/Analysis/string.c
@@ -154,6 +154,23 @@
   clang_analyzer_eval(strlen(x) < 5); // expected-warning{{FALSE}}
 }
 
+
+size_t strlenWrapper(const char *str) {
+  return strlen(str);
+}
+
+extern void invalidate(char *s);
+
+void testStrlenCallee() {
+  char str[42];
+  invalidate(str);
+  size_t lenBefore = strlenWrapper(str);
+  invalidate(str);
+  size_t lenAfter = strlenWrapper(str);
+  clang_analyzer_eval(lenBefore == lenAfter); // expected-warning{{UNKNOWN}}
+}
+
+
 //===----------------------------------------------------------------------===
 // strnlen()
 //===----------------------------------------------------------------------===