diff --git a/lib/Checker/SymbolManager.cpp b/lib/Checker/SymbolManager.cpp
new file mode 100644
index 0000000..40bdcf6
--- /dev/null
+++ b/lib/Checker/SymbolManager.cpp
@@ -0,0 +1,228 @@
+//== SymbolManager.h - Management of Symbolic Values ------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines SymbolManager, a class that manages symbolic values
+//  created for use by GRExprEngine and related classes.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Checker/PathSensitive/SymbolManager.h"
+#include "clang/Checker/PathSensitive/MemRegion.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+
+void SymExpr::dump() const {
+  dumpToStream(llvm::errs());
+}
+
+static void print(llvm::raw_ostream& os, BinaryOperator::Opcode Op) {
+  switch (Op) {
+    default:
+      assert(false && "operator printing not implemented");
+      break;
+    case BinaryOperator::Mul: os << '*'  ; break;
+    case BinaryOperator::Div: os << '/'  ; break;
+    case BinaryOperator::Rem: os << '%'  ; break;
+    case BinaryOperator::Add: os << '+'  ; break;
+    case BinaryOperator::Sub: os << '-'  ; break;
+    case BinaryOperator::Shl: os << "<<" ; break;
+    case BinaryOperator::Shr: os << ">>" ; break;
+    case BinaryOperator::LT:  os << "<"  ; break;
+    case BinaryOperator::GT:  os << '>'  ; break;
+    case BinaryOperator::LE:  os << "<=" ; break;
+    case BinaryOperator::GE:  os << ">=" ; break;
+    case BinaryOperator::EQ:  os << "==" ; break;
+    case BinaryOperator::NE:  os << "!=" ; break;
+    case BinaryOperator::And: os << '&'  ; break;
+    case BinaryOperator::Xor: os << '^'  ; break;
+    case BinaryOperator::Or:  os << '|'  ; break;
+  }
+}
+
+void SymIntExpr::dumpToStream(llvm::raw_ostream& os) const {
+  os << '(';
+  getLHS()->dumpToStream(os);
+  os << ") ";
+  print(os, getOpcode());
+  os << ' ' << getRHS().getZExtValue();
+  if (getRHS().isUnsigned()) os << 'U';
+}
+
+void SymSymExpr::dumpToStream(llvm::raw_ostream& os) const {
+  os << '(';
+  getLHS()->dumpToStream(os);
+  os << ") ";
+  os << '(';
+  getRHS()->dumpToStream(os);
+  os << ')';
+}
+
+void SymbolConjured::dumpToStream(llvm::raw_ostream& os) const {
+  os << "conj_$" << getSymbolID() << '{' << T.getAsString() << '}';
+}
+
+void SymbolDerived::dumpToStream(llvm::raw_ostream& os) const {
+  os << "derived_$" << getSymbolID() << '{'
+     << getParentSymbol() << ',' << getRegion() << '}';
+}
+
+void SymbolRegionValue::dumpToStream(llvm::raw_ostream& os) const {
+  os << "reg_$" << getSymbolID() << "<" << R << ">";
+}
+
+const SymbolRegionValue*
+SymbolManager::getRegionValueSymbol(const MemRegion* R, QualType T) {
+  llvm::FoldingSetNodeID profile;
+  SymbolRegionValue::Profile(profile, R, T);
+  void* InsertPos;
+  SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
+  if (!SD) {
+    SD = (SymExpr*) BPAlloc.Allocate<SymbolRegionValue>();
+    new (SD) SymbolRegionValue(SymbolCounter, R, T);
+    DataSet.InsertNode(SD, InsertPos);
+    ++SymbolCounter;
+  }
+
+  return cast<SymbolRegionValue>(SD);
+}
+
+const SymbolConjured*
+SymbolManager::getConjuredSymbol(const Stmt* E, QualType T, unsigned Count,
+                                 const void* SymbolTag) {
+
+  llvm::FoldingSetNodeID profile;
+  SymbolConjured::Profile(profile, E, T, Count, SymbolTag);
+  void* InsertPos;
+  SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
+  if (!SD) {
+    SD = (SymExpr*) BPAlloc.Allocate<SymbolConjured>();
+    new (SD) SymbolConjured(SymbolCounter, E, T, Count, SymbolTag);
+    DataSet.InsertNode(SD, InsertPos);
+    ++SymbolCounter;
+  }
+
+  return cast<SymbolConjured>(SD);
+}
+
+const SymbolDerived*
+SymbolManager::getDerivedSymbol(SymbolRef parentSymbol,
+                                const TypedRegion *R) {
+
+  llvm::FoldingSetNodeID profile;
+  SymbolDerived::Profile(profile, parentSymbol, R);
+  void* InsertPos;
+  SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
+  if (!SD) {
+    SD = (SymExpr*) BPAlloc.Allocate<SymbolDerived>();
+    new (SD) SymbolDerived(SymbolCounter, parentSymbol, R);
+    DataSet.InsertNode(SD, InsertPos);
+    ++SymbolCounter;
+  }
+
+  return cast<SymbolDerived>(SD);
+}
+
+const SymIntExpr *SymbolManager::getSymIntExpr(const SymExpr *lhs,
+                                               BinaryOperator::Opcode op,
+                                               const llvm::APSInt& v,
+                                               QualType t) {
+  llvm::FoldingSetNodeID ID;
+  SymIntExpr::Profile(ID, lhs, op, v, t);
+  void *InsertPos;
+  SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
+
+  if (!data) {
+    data = (SymIntExpr*) BPAlloc.Allocate<SymIntExpr>();
+    new (data) SymIntExpr(lhs, op, v, t);
+    DataSet.InsertNode(data, InsertPos);
+  }
+
+  return cast<SymIntExpr>(data);
+}
+
+const SymSymExpr *SymbolManager::getSymSymExpr(const SymExpr *lhs,
+                                               BinaryOperator::Opcode op,
+                                               const SymExpr *rhs,
+                                               QualType t) {
+  llvm::FoldingSetNodeID ID;
+  SymSymExpr::Profile(ID, lhs, op, rhs, t);
+  void *InsertPos;
+  SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
+
+  if (!data) {
+    data = (SymSymExpr*) BPAlloc.Allocate<SymSymExpr>();
+    new (data) SymSymExpr(lhs, op, rhs, t);
+    DataSet.InsertNode(data, InsertPos);
+  }
+
+  return cast<SymSymExpr>(data);
+}
+
+QualType SymbolConjured::getType(ASTContext&) const {
+  return T;
+}
+
+
+QualType SymbolDerived::getType(ASTContext& Ctx) const {
+  return R->getValueType(Ctx);
+}
+
+QualType SymbolRegionValue::getType(ASTContext& C) const {
+  if (!T.isNull())
+    return T;
+
+  if (const TypedRegion* TR = dyn_cast<TypedRegion>(R))
+    return TR->getValueType(C);
+
+  return QualType();
+}
+
+SymbolManager::~SymbolManager() {}
+
+bool SymbolManager::canSymbolicate(QualType T) {
+  return Loc::IsLocType(T) || (T->isIntegerType() && T->isScalarType());
+}
+
+void SymbolReaper::markLive(SymbolRef sym) {
+  TheLiving.insert(sym);
+  TheDead.erase(sym);
+}
+
+bool SymbolReaper::maybeDead(SymbolRef sym) {
+  if (isLive(sym))
+    return false;
+
+  TheDead.insert(sym);
+  return true;
+}
+
+bool SymbolReaper::isLive(SymbolRef sym) {
+  if (TheLiving.count(sym))
+    return true;
+
+  if (const SymbolDerived *derived = dyn_cast<SymbolDerived>(sym)) {
+    if (isLive(derived->getParentSymbol())) {
+      markLive(sym);
+      return true;
+    }
+    return false;
+  }
+
+  // Interogate the symbol.  It may derive from an input value to
+  // the analyzed function/method.
+  return isa<SymbolRegionValue>(sym);
+}
+
+bool SymbolReaper::isLive(const Stmt *Loc, const VarRegion *VR) const {
+  const StackFrameContext *SFC = VR->getStackFrame();
+  return SFC == CurrentStackFrame ? Liveness.isLive(Loc, VR->getDecl()) : true;
+}
+
+SymbolVisitor::~SymbolVisitor() {}