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diff --git a/lib/StaticAnalyzer/Core/RangedConstraintManager.cpp b/lib/StaticAnalyzer/Core/RangedConstraintManager.cpp
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+++ b/lib/StaticAnalyzer/Core/RangedConstraintManager.cpp
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+//== RangedConstraintManager.cpp --------------------------------*- 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 RangedConstraintManager, a class that provides a
+//  range-based constraint manager interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RangedConstraintManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
+
+namespace clang {
+
+namespace ento {
+
+RangedConstraintManager::~RangedConstraintManager() {}
+
+ProgramStateRef RangedConstraintManager::assumeSym(ProgramStateRef State,
+                                                   SymbolRef Sym,
+                                                   bool Assumption) {
+  // Handle SymbolData.
+  if (isa<SymbolData>(Sym)) {
+    return assumeSymUnsupported(State, Sym, Assumption);
+
+    // Handle symbolic expression.
+  } else if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(Sym)) {
+    // We can only simplify expressions whose RHS is an integer.
+
+    BinaryOperator::Opcode op = SIE->getOpcode();
+    if (BinaryOperator::isComparisonOp(op)) {
+      if (!Assumption)
+        op = BinaryOperator::negateComparisonOp(op);
+
+      return assumeSymRel(State, SIE->getLHS(), op, SIE->getRHS());
+    }
+
+  } else if (const SymSymExpr *SSE = dyn_cast<SymSymExpr>(Sym)) {
+    // Translate "a != b" to "(b - a) != 0".
+    // We invert the order of the operands as a heuristic for how loop
+    // conditions are usually written ("begin != end") as compared to length
+    // calculations ("end - begin"). The more correct thing to do would be to
+    // canonicalize "a - b" and "b - a", which would allow us to treat
+    // "a != b" and "b != a" the same.
+    SymbolManager &SymMgr = getSymbolManager();
+    BinaryOperator::Opcode Op = SSE->getOpcode();
+    assert(BinaryOperator::isComparisonOp(Op));
+
+    // For now, we only support comparing pointers.
+    assert(Loc::isLocType(SSE->getLHS()->getType()));
+    assert(Loc::isLocType(SSE->getRHS()->getType()));
+    QualType DiffTy = SymMgr.getContext().getPointerDiffType();
+    SymbolRef Subtraction =
+        SymMgr.getSymSymExpr(SSE->getRHS(), BO_Sub, SSE->getLHS(), DiffTy);
+
+    const llvm::APSInt &Zero = getBasicVals().getValue(0, DiffTy);
+    Op = BinaryOperator::reverseComparisonOp(Op);
+    if (!Assumption)
+      Op = BinaryOperator::negateComparisonOp(Op);
+    return assumeSymRel(State, Subtraction, Op, Zero);
+  }
+
+  // If we get here, there's nothing else we can do but treat the symbol as
+  // opaque.
+  return assumeSymUnsupported(State, Sym, Assumption);
+}
+
+ProgramStateRef RangedConstraintManager::assumeSymInclusiveRange(
+    ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
+    const llvm::APSInt &To, bool InRange) {
+  // Get the type used for calculating wraparound.
+  BasicValueFactory &BVF = getBasicVals();
+  APSIntType WraparoundType = BVF.getAPSIntType(Sym->getType());
+
+  llvm::APSInt Adjustment = WraparoundType.getZeroValue();
+  SymbolRef AdjustedSym = Sym;
+  computeAdjustment(AdjustedSym, Adjustment);
+
+  // Convert the right-hand side integer as necessary.
+  APSIntType ComparisonType = std::max(WraparoundType, APSIntType(From));
+  llvm::APSInt ConvertedFrom = ComparisonType.convert(From);
+  llvm::APSInt ConvertedTo = ComparisonType.convert(To);
+
+  // Prefer unsigned comparisons.
+  if (ComparisonType.getBitWidth() == WraparoundType.getBitWidth() &&
+      ComparisonType.isUnsigned() && !WraparoundType.isUnsigned())
+    Adjustment.setIsSigned(false);
+
+  if (InRange)
+    return assumeSymWithinInclusiveRange(State, AdjustedSym, ConvertedFrom,
+                                         ConvertedTo, Adjustment);
+  return assumeSymOutsideInclusiveRange(State, AdjustedSym, ConvertedFrom,
+                                        ConvertedTo, Adjustment);
+}
+
+ProgramStateRef
+RangedConstraintManager::assumeSymUnsupported(ProgramStateRef State,
+                                              SymbolRef Sym, bool Assumption) {
+  BasicValueFactory &BVF = getBasicVals();
+  QualType T = Sym->getType();
+
+  // Non-integer types are not supported.
+  if (!T->isIntegralOrEnumerationType())
+    return State;
+
+  // Reverse the operation and add directly to state.
+  const llvm::APSInt &Zero = BVF.getValue(0, T);
+  if (Assumption)
+    return assumeSymNE(State, Sym, Zero, Zero);
+  else
+    return assumeSymEQ(State, Sym, Zero, Zero);
+}
+
+ProgramStateRef RangedConstraintManager::assumeSymRel(ProgramStateRef State,
+                                                      SymbolRef Sym,
+                                                      BinaryOperator::Opcode Op,
+                                                      const llvm::APSInt &Int) {
+  assert(BinaryOperator::isComparisonOp(Op) &&
+         "Non-comparison ops should be rewritten as comparisons to zero.");
+
+  // Simplification: translate an assume of a constraint of the form
+  // "(exp comparison_op expr) != 0" to true into an assume of
+  // "exp comparison_op expr" to true. (And similarly, an assume of the form
+  // "(exp comparison_op expr) == 0" to true into an assume of
+  // "exp comparison_op expr" to false.)
+  if (Int == 0 && (Op == BO_EQ || Op == BO_NE)) {
+    if (const BinarySymExpr *SE = dyn_cast<BinarySymExpr>(Sym))
+      if (BinaryOperator::isComparisonOp(SE->getOpcode()))
+        return assumeSym(State, Sym, (Op == BO_NE ? true : false));
+  }
+
+  // Get the type used for calculating wraparound.
+  BasicValueFactory &BVF = getBasicVals();
+  APSIntType WraparoundType = BVF.getAPSIntType(Sym->getType());
+
+  // We only handle simple comparisons of the form "$sym == constant"
+  // or "($sym+constant1) == constant2".
+  // The adjustment is "constant1" in the above expression. It's used to
+  // "slide" the solution range around for modular arithmetic. For example,
+  // x < 4 has the solution [0, 3]. x+2 < 4 has the solution [0-2, 3-2], which
+  // in modular arithmetic is [0, 1] U [UINT_MAX-1, UINT_MAX]. It's up to
+  // the subclasses of SimpleConstraintManager to handle the adjustment.
+  llvm::APSInt Adjustment = WraparoundType.getZeroValue();
+  computeAdjustment(Sym, Adjustment);
+
+  // Convert the right-hand side integer as necessary.
+  APSIntType ComparisonType = std::max(WraparoundType, APSIntType(Int));
+  llvm::APSInt ConvertedInt = ComparisonType.convert(Int);
+
+  // Prefer unsigned comparisons.
+  if (ComparisonType.getBitWidth() == WraparoundType.getBitWidth() &&
+      ComparisonType.isUnsigned() && !WraparoundType.isUnsigned())
+    Adjustment.setIsSigned(false);
+
+  switch (Op) {
+  default:
+    llvm_unreachable("invalid operation not caught by assertion above");
+
+  case BO_EQ:
+    return assumeSymEQ(State, Sym, ConvertedInt, Adjustment);
+
+  case BO_NE:
+    return assumeSymNE(State, Sym, ConvertedInt, Adjustment);
+
+  case BO_GT:
+    return assumeSymGT(State, Sym, ConvertedInt, Adjustment);
+
+  case BO_GE:
+    return assumeSymGE(State, Sym, ConvertedInt, Adjustment);
+
+  case BO_LT:
+    return assumeSymLT(State, Sym, ConvertedInt, Adjustment);
+
+  case BO_LE:
+    return assumeSymLE(State, Sym, ConvertedInt, Adjustment);
+  } // end switch
+}
+
+void RangedConstraintManager::computeAdjustment(SymbolRef &Sym,
+                                                llvm::APSInt &Adjustment) {
+  // Is it a "($sym+constant1)" expression?
+  if (const SymIntExpr *SE = dyn_cast<SymIntExpr>(Sym)) {
+    BinaryOperator::Opcode Op = SE->getOpcode();
+    if (Op == BO_Add || Op == BO_Sub) {
+      Sym = SE->getLHS();
+      Adjustment = APSIntType(Adjustment).convert(SE->getRHS());
+
+      // Don't forget to negate the adjustment if it's being subtracted.
+      // This should happen /after/ promotion, in case the value being
+      // subtracted is, say, CHAR_MIN, and the promoted type is 'int'.
+      if (Op == BO_Sub)
+        Adjustment = -Adjustment;
+    }
+  }
+}
+
+} // end of namespace ento
+
+} // end of namespace clang