[analyzer] Add new Z3 constraint manager backend

Summary: Implement new Z3 constraint manager backend.

Reviewers: zaks.anna, dcoughlin, NoQ, xazax.hun

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D28952

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@299463 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 1634 insertions, 0 deletions

diff --git a/lib/StaticAnalyzer/Core/CMakeLists.txt b/lib/StaticAnalyzer/Core/CMakeLists.txt
index 0b4606ba17..85878f5e96 100644
--- a/lib/StaticAnalyzer/Core/CMakeLists.txt
+++ b/lib/StaticAnalyzer/Core/CMakeLists.txt
@@ -1,5 +1,12 @@
 set(LLVM_LINK_COMPONENTS support)
 
+# Link Z3 if the user wants to build it.
+if(CLANG_ANALYZER_WITH_Z3)
+  set(Z3_LINK_FILES ${Z3_LIBRARIES})
+else()
+  set(Z3_LINK_FILES "")
+endif()
+
 add_clang_library(clangStaticAnalyzerCore
   APSIntType.cpp
   AnalysisManager.cpp
@@ -43,6 +50,7 @@ add_clang_library(clangStaticAnalyzerCore
   Store.cpp
   SubEngine.cpp
   SymbolManager.cpp
+  Z3ConstraintManager.cpp
 
   LINK_LIBS
   clangAST
@@ -50,4 +58,12 @@ add_clang_library(clangStaticAnalyzerCore
   clangBasic
   clangLex
   clangRewrite
+  ${Z3_LINK_FILES}
   )
+
+if(CLANG_ANALYZER_WITH_Z3)
+  target_include_directories(clangStaticAnalyzerCore SYSTEM
+    PRIVATE
+    ${Z3_INCLUDE_DIR}
+    )
+endif()
diff --git a/lib/StaticAnalyzer/Core/Z3ConstraintManager.cpp b/lib/StaticAnalyzer/Core/Z3ConstraintManager.cpp
new file mode 100644
index 0000000000..f9f9057a89
--- /dev/null
+++ b/lib/StaticAnalyzer/Core/Z3ConstraintManager.cpp
@@ -0,0 +1,1618 @@
+//== Z3ConstraintManager.cpp --------------------------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/TargetInfo.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/SimpleConstraintManager.h"
+
+#include "clang/Config/config.h"
+
+using namespace clang;
+using namespace ento;
+
+#if CLANG_ANALYZER_WITH_Z3
+
+#include <z3.h>
+
+// Forward declarations
+namespace {
+class Z3Expr;
+class ConstraintZ3 {};
+} // end anonymous namespace
+
+typedef llvm::ImmutableSet<std::pair<SymbolRef, Z3Expr>> ConstraintZ3Ty;
+
+// Expansion of REGISTER_TRAIT_WITH_PROGRAMSTATE(ConstraintZ3, Z3SetPair)
+namespace clang {
+namespace ento {
+template <>
+struct ProgramStateTrait<ConstraintZ3>
+    : public ProgramStatePartialTrait<ConstraintZ3Ty> {
+  static void *GDMIndex() {
+    static int Index;
+    return &Index;
+  }
+};
+} // end namespace ento
+} // end namespace clang
+
+namespace {
+
+class Z3Config {
+  friend class Z3Context;
+
+  Z3_config Config;
+
+public:
+  Z3Config() : Config(Z3_mk_config()) {
+    // Enable model finding
+    Z3_set_param_value(Config, "model", "true");
+    // Disable proof generation
+    Z3_set_param_value(Config, "proof", "false");
+    // Set timeout to 15000ms = 15s
+    Z3_set_param_value(Config, "timeout", "15000");
+  }
+
+  ~Z3Config() { Z3_del_config(Config); }
+}; // end class Z3Config
+
+class Z3Context {
+  Z3_context ZC_P;
+
+public:
+  static Z3_context ZC;
+
+  Z3Context() : ZC_P(Z3_mk_context_rc(Z3Config().Config)) { ZC = ZC_P; }
+
+  ~Z3Context() {
+    Z3_del_context(ZC);
+    Z3_finalize_memory();
+    ZC_P = nullptr;
+  }
+}; // end class Z3Context
+
+class Z3Sort {
+  friend class Z3Expr;
+
+  Z3_sort Sort;
+
+  Z3Sort() : Sort(nullptr) {}
+  Z3Sort(Z3_sort ZS) : Sort(ZS) {
+    Z3_inc_ref(Z3Context::ZC, reinterpret_cast<Z3_ast>(Sort));
+  }
+
+public:
+  /// Override implicit copy constructor for correct reference counting.
+  Z3Sort(const Z3Sort &Copy) : Sort(Copy.Sort) {
+    Z3_inc_ref(Z3Context::ZC, reinterpret_cast<Z3_ast>(Sort));
+  }
+
+  /// Provide move constructor
+  Z3Sort(Z3Sort &&Move) : Sort(nullptr) { *this = std::move(Move); }
+
+  /// Provide move assignment constructor
+  Z3Sort &operator=(Z3Sort &&Move) {
+    if (this != &Move) {
+      if (Sort)
+        Z3_dec_ref(Z3Context::ZC, reinterpret_cast<Z3_ast>(Sort));
+      Sort = Move.Sort;
+      Move.Sort = nullptr;
+    }
+    return *this;
+  }
+
+  ~Z3Sort() {
+    if (Sort)
+      Z3_dec_ref(Z3Context::ZC, reinterpret_cast<Z3_ast>(Sort));
+  }
+
+  // Return a boolean sort.
+  static Z3Sort getBoolSort() { return Z3Sort(Z3_mk_bool_sort(Z3Context::ZC)); }
+
+  // Return an appropriate bitvector sort for the given bitwidth.
+  static Z3Sort getBitvectorSort(unsigned BitWidth) {
+    return Z3Sort(Z3_mk_bv_sort(Z3Context::ZC, BitWidth));
+  }
+
+  // Return an appropriate floating-point sort for the given bitwidth.
+  static Z3Sort getFloatSort(unsigned BitWidth) {
+    Z3_sort Sort;
+
+    switch (BitWidth) {
+    default:
+      llvm_unreachable("Unsupported floating-point bitwidth!");
+      break;
+    case 16:
+      Sort = Z3_mk_fpa_sort_16(Z3Context::ZC);
+      break;
+    case 32:
+      Sort = Z3_mk_fpa_sort_32(Z3Context::ZC);
+      break;
+    case 64:
+      Sort = Z3_mk_fpa_sort_64(Z3Context::ZC);
+      break;
+    case 128:
+      Sort = Z3_mk_fpa_sort_128(Z3Context::ZC);
+      break;
+    }
+    return Z3Sort(Sort);
+  }
+
+  // Return an appropriate sort for the given AST.
+  static Z3Sort getSort(Z3_ast AST) {
+    return Z3Sort(Z3_get_sort(Z3Context::ZC, AST));
+  }
+
+  Z3_sort_kind getSortKind() const {
+    return Z3_get_sort_kind(Z3Context::ZC, Sort);
+  }
+
+  unsigned getBitvectorSortSize() const {
+    assert(getSortKind() == Z3_BV_SORT && "Not a bitvector sort!");
+    return Z3_get_bv_sort_size(Z3Context::ZC, Sort);
+  }
+
+  unsigned getFloatSortSize() const {
+    assert(getSortKind() == Z3_FLOATING_POINT_SORT &&
+           "Not a floating-point sort!");
+    return Z3_fpa_get_ebits(Z3Context::ZC, Sort) +
+           Z3_fpa_get_sbits(Z3Context::ZC, Sort);
+  }
+
+  bool operator==(const Z3Sort &Other) const {
+    return Z3_is_eq_sort(Z3Context::ZC, Sort, Other.Sort);
+  }
+
+  Z3Sort &operator=(const Z3Sort &Move) {
+    Z3_inc_ref(Z3Context::ZC, reinterpret_cast<Z3_ast>(Move.Sort));
+    Z3_dec_ref(Z3Context::ZC, reinterpret_cast<Z3_ast>(Sort));
+    Sort = Move.Sort;
+    return *this;
+  }
+
+  void print(raw_ostream &OS) const {
+    OS << Z3_sort_to_string(Z3Context::ZC, Sort);
+  }
+
+  LLVM_DUMP_METHOD void dump() const { print(llvm::errs()); }
+}; // end class Z3Sort
+
+class Z3Expr {
+  friend class Z3Model;
+  friend class Z3Solver;
+
+  Z3_ast AST;
+
+  Z3Expr(Z3_ast ZA) : AST(ZA) { Z3_inc_ref(Z3Context::ZC, AST); }
+
+  // Return an appropriate floating-point rounding mode.
+  static Z3Expr getFloatRoundingMode() {
+    // TODO: Don't assume nearest ties to even rounding mode
+    return Z3Expr(Z3_mk_fpa_rne(Z3Context::ZC));
+  }
+
+  // Determine whether two float semantics are equivalent
+  static bool areEquivalent(const llvm::fltSemantics &LHS,
+                            const llvm::fltSemantics &RHS) {
+    return (llvm::APFloat::semanticsPrecision(LHS) ==
+            llvm::APFloat::semanticsPrecision(RHS)) &&
+           (llvm::APFloat::semanticsMinExponent(LHS) ==
+            llvm::APFloat::semanticsMinExponent(RHS)) &&
+           (llvm::APFloat::semanticsMaxExponent(LHS) ==
+            llvm::APFloat::semanticsMaxExponent(RHS)) &&
+           (llvm::APFloat::semanticsSizeInBits(LHS) ==
+            llvm::APFloat::semanticsSizeInBits(RHS));
+  }
+
+public:
+  /// Override implicit copy constructor for correct reference counting.
+  Z3Expr(const Z3Expr &Copy) : AST(Copy.AST) { Z3_inc_ref(Z3Context::ZC, AST); }
+
+  /// Provide move constructor
+  Z3Expr(Z3Expr &&Move) : AST(nullptr) { *this = std::move(Move); }
+
+  /// Provide move assignment constructor
+  Z3Expr &operator=(Z3Expr &&Move) {
+    if (this != &Move) {
+      if (AST)
+        Z3_dec_ref(Z3Context::ZC, AST);
+      AST = Move.AST;
+      Move.AST = nullptr;
+    }
+    return *this;
+  }
+
+  ~Z3Expr() {
+    if (AST)
+      Z3_dec_ref(Z3Context::ZC, AST);
+  }
+
+  /// Get the corresponding IEEE floating-point type for a given bitwidth.
+  static const llvm::fltSemantics &getFloatSemantics(unsigned BitWidth) {
+    switch (BitWidth) {
+    default:
+      llvm_unreachable("Unsupported floating-point semantics!");
+      break;
+    case 16:
+      return llvm::APFloat::IEEEhalf();
+    case 32:
+      return llvm::APFloat::IEEEsingle();
+    case 64:
+      return llvm::APFloat::IEEEdouble();
+    case 128:
+      return llvm::APFloat::IEEEquad();
+    }
+  }
+
+  /// Construct a Z3Expr from a unary operator, given a Z3_context.
+  static Z3Expr fromUnOp(const UnaryOperator::Opcode Op, const Z3Expr &Exp) {
+    Z3_ast AST;
+
+    switch (Op) {
+    default:
+      llvm_unreachable("Unimplemented opcode");
+      break;
+
+    case UO_Minus:
+      AST = Z3_mk_bvneg(Z3Context::ZC, Exp.AST);
+      break;
+
+    case UO_Not:
+      AST = Z3_mk_bvnot(Z3Context::ZC, Exp.AST);
+      break;
+
+    case UO_LNot:
+      AST = Z3_mk_not(Z3Context::ZC, Exp.AST);
+      break;
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a floating-point unary operator, given a
+  /// Z3_context.
+  static Z3Expr fromFloatUnOp(const UnaryOperator::Opcode Op,
+                              const Z3Expr &Exp) {
+    Z3_ast AST;
+
+    switch (Op) {
+    default:
+      llvm_unreachable("Unimplemented opcode");
+      break;
+
+    case UO_Minus:
+      AST = Z3_mk_fpa_neg(Z3Context::ZC, Exp.AST);
+      break;
+
+    case UO_LNot:
+      return Z3Expr::fromUnOp(Op, Exp);
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a n-ary binary operator.
+  static Z3Expr fromNBinOp(const BinaryOperator::Opcode Op,
+                           const std::vector<Z3_ast> &ASTs) {
+    Z3_ast AST;
+
+    switch (Op) {
+    default:
+      llvm_unreachable("Unimplemented opcode");
+      break;
+
+    case BO_LAnd:
+      AST = Z3_mk_and(Z3Context::ZC, ASTs.size(), ASTs.data());
+      break;
+
+    case BO_LOr:
+      AST = Z3_mk_or(Z3Context::ZC, ASTs.size(), ASTs.data());
+      break;
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a binary operator, given a Z3_context.
+  static Z3Expr fromBinOp(const Z3Expr &LHS, const BinaryOperator::Opcode Op,
+                          const Z3Expr &RHS, bool isSigned) {
+    Z3_ast AST;
+
+    assert(Z3Sort::getSort(LHS.AST) == Z3Sort::getSort(RHS.AST) &&
+           "AST's must have the same sort!");
+
+    switch (Op) {
+    default:
+      llvm_unreachable("Unimplemented opcode");
+      break;
+
+    // Multiplicative operators
+    case BO_Mul:
+      AST = Z3_mk_bvmul(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_Div:
+      AST = isSigned ? Z3_mk_bvsdiv(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvudiv(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_Rem:
+      AST = isSigned ? Z3_mk_bvsrem(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvurem(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Additive operators
+    case BO_Add:
+      AST = Z3_mk_bvadd(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_Sub:
+      AST = Z3_mk_bvsub(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Bitwise shift operators
+    case BO_Shl:
+      AST = Z3_mk_bvshl(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_Shr:
+      AST = isSigned ? Z3_mk_bvashr(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvlshr(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Relational operators
+    case BO_LT:
+      AST = isSigned ? Z3_mk_bvslt(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvult(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_GT:
+      AST = isSigned ? Z3_mk_bvsgt(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvugt(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_LE:
+      AST = isSigned ? Z3_mk_bvsle(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvule(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_GE:
+      AST = isSigned ? Z3_mk_bvsge(Z3Context::ZC, LHS.AST, RHS.AST)
+                     : Z3_mk_bvuge(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Equality operators
+    case BO_EQ:
+      AST = Z3_mk_eq(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_NE:
+      return Z3Expr::fromUnOp(UO_LNot,
+                              Z3Expr::fromBinOp(LHS, BO_EQ, RHS, isSigned));
+      break;
+
+    // Bitwise operators
+    case BO_And:
+      AST = Z3_mk_bvand(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_Xor:
+      AST = Z3_mk_bvxor(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_Or:
+      AST = Z3_mk_bvor(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Logical operators
+    case BO_LAnd:
+    case BO_LOr: {
+      std::vector<Z3_ast> Args = {LHS.AST, RHS.AST};
+      return Z3Expr::fromNBinOp(Op, Args);
+    }
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a special floating-point binary operator, given
+  /// a Z3_context.
+  static Z3Expr fromFloatSpecialBinOp(const Z3Expr &LHS,
+                                      const BinaryOperator::Opcode Op,
+                                      const llvm::APFloat::fltCategory &RHS) {
+    Z3_ast AST;
+
+    switch (Op) {
+    default:
+      llvm_unreachable("Unimplemented opcode");
+      break;
+
+    // Equality operators
+    case BO_EQ:
+      switch (RHS) {
+      case llvm::APFloat::fcInfinity:
+        AST = Z3_mk_fpa_is_infinite(Z3Context::ZC, LHS.AST);
+        break;
+      case llvm::APFloat::fcNaN:
+        AST = Z3_mk_fpa_is_nan(Z3Context::ZC, LHS.AST);
+        break;
+      case llvm::APFloat::fcNormal:
+        AST = Z3_mk_fpa_is_normal(Z3Context::ZC, LHS.AST);
+        break;
+      case llvm::APFloat::fcZero:
+        AST = Z3_mk_fpa_is_zero(Z3Context::ZC, LHS.AST);
+        break;
+      }
+      break;
+    case BO_NE:
+      return Z3Expr::fromFloatUnOp(
+          UO_LNot, Z3Expr::fromFloatSpecialBinOp(LHS, BO_EQ, RHS));
+      break;
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a floating-point binary operator, given a
+  /// Z3_context.
+  static Z3Expr fromFloatBinOp(const Z3Expr &LHS,
+                               const BinaryOperator::Opcode Op,
+                               const Z3Expr &RHS) {
+    Z3_ast AST;
+
+    assert(Z3Sort::getSort(LHS.AST) == Z3Sort::getSort(RHS.AST) &&
+           "AST's must have the same sort!");
+
+    switch (Op) {
+    default:
+      llvm_unreachable("Unimplemented opcode");
+      break;
+
+    // Multiplicative operators
+    case BO_Mul: {
+      Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+      AST = Z3_mk_fpa_mul(Z3Context::ZC, RoundingMode.AST, LHS.AST, RHS.AST);
+      break;
+    }
+    case BO_Div: {
+      Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+      AST = Z3_mk_fpa_div(Z3Context::ZC, RoundingMode.AST, LHS.AST, RHS.AST);
+      break;
+    }
+    case BO_Rem:
+      AST = Z3_mk_fpa_rem(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Additive operators
+    case BO_Add: {
+      Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+      AST = Z3_mk_fpa_add(Z3Context::ZC, RoundingMode.AST, LHS.AST, RHS.AST);
+      break;
+    }
+    case BO_Sub: {
+      Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+      AST = Z3_mk_fpa_sub(Z3Context::ZC, RoundingMode.AST, LHS.AST, RHS.AST);
+      break;
+    }
+
+    // Relational operators
+    case BO_LT:
+      AST = Z3_mk_fpa_lt(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_GT:
+      AST = Z3_mk_fpa_gt(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_LE:
+      AST = Z3_mk_fpa_leq(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_GE:
+      AST = Z3_mk_fpa_geq(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+
+    // Equality operators
+    case BO_EQ:
+      AST = Z3_mk_fpa_eq(Z3Context::ZC, LHS.AST, RHS.AST);
+      break;
+    case BO_NE:
+      return Z3Expr::fromFloatUnOp(UO_LNot,
+                                   Z3Expr::fromFloatBinOp(LHS, BO_EQ, RHS));
+      break;
+
+    // Logical operators
+    case BO_LAnd:
+    case BO_LOr:
+      return Z3Expr::fromBinOp(LHS, Op, RHS, false);
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a SymbolData, given a Z3_context.
+  static Z3Expr fromData(const SymbolID ID, bool isBool, bool isFloat,
+                         uint64_t BitWidth) {
+    llvm::Twine Name = "$" + llvm::Twine(ID);
+
+    Z3Sort Sort;
+    if (isBool)
+      Sort = Z3Sort::getBoolSort();
+    else if (isFloat)
+      Sort = Z3Sort::getFloatSort(BitWidth);
+    else
+      Sort = Z3Sort::getBitvectorSort(BitWidth);
+
+    Z3_symbol Symbol = Z3_mk_string_symbol(Z3Context::ZC, Name.str().c_str());
+    Z3_ast AST = Z3_mk_const(Z3Context::ZC, Symbol, Sort.Sort);
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a SymbolCast, given a Z3_context.
+  static Z3Expr fromCast(const Z3Expr &Exp, QualType ToTy, uint64_t ToBitWidth,
+                         QualType FromTy, uint64_t FromBitWidth) {
+    Z3_ast AST;
+
+    if ((FromTy->isIntegralOrEnumerationType() &&
+         ToTy->isIntegralOrEnumerationType()) ||
+        (FromTy->isAnyPointerType() ^ ToTy->isAnyPointerType()) ||
+        (FromTy->isBlockPointerType() ^ ToTy->isBlockPointerType()) ||
+        (FromTy->isReferenceType() ^ ToTy->isReferenceType())) {
+      // Special case: Z3 boolean type is distinct from bitvector type, so
+      // must use if-then-else expression instead of direct cast
+      if (FromTy->isBooleanType()) {
+        assert(ToBitWidth > 0 && "BitWidth must be positive!");
+        Z3Expr Zero = Z3Expr::fromInt("0", ToBitWidth);
+        Z3Expr One = Z3Expr::fromInt("1", ToBitWidth);
+        AST = Z3_mk_ite(Z3Context::ZC, Exp.AST, One.AST, Zero.AST);
+      } else if (ToBitWidth > FromBitWidth) {
+        AST = FromTy->isSignedIntegerOrEnumerationType()
+                  ? Z3_mk_sign_ext(Z3Context::ZC, ToBitWidth - FromBitWidth,
+                                   Exp.AST)
+                  : Z3_mk_zero_ext(Z3Context::ZC, ToBitWidth - FromBitWidth,
+                                   Exp.AST);
+      } else if (ToBitWidth < FromBitWidth) {
+        AST = Z3_mk_extract(Z3Context::ZC, ToBitWidth - 1, 0, Exp.AST);
+      } else {
+        // Both are bitvectors with the same width, ignore the type cast
+        return Exp;
+      }
+    } else if (FromTy->isRealFloatingType() && ToTy->isRealFloatingType()) {
+      if (ToBitWidth != FromBitWidth) {
+        Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+        Z3Sort Sort = Z3Sort::getFloatSort(ToBitWidth);
+        AST = Z3_mk_fpa_to_fp_float(Z3Context::ZC, RoundingMode.AST, Exp.AST,
+                                    Sort.Sort);
+      } else {
+        return Exp;
+      }
+    } else if (FromTy->isIntegralOrEnumerationType() &&
+               ToTy->isRealFloatingType()) {
+      Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+      Z3Sort Sort = Z3Sort::getFloatSort(ToBitWidth);
+      AST = FromTy->isSignedIntegerOrEnumerationType()
+                ? Z3_mk_fpa_to_fp_signed(Z3Context::ZC, RoundingMode.AST,
+                                         Exp.AST, Sort.Sort)
+                : Z3_mk_fpa_to_fp_unsigned(Z3Context::ZC, RoundingMode.AST,
+                                           Exp.AST, Sort.Sort);
+    } else if (FromTy->isRealFloatingType() &&
+               ToTy->isIntegralOrEnumerationType()) {
+      Z3Expr RoundingMode = Z3Expr::getFloatRoundingMode();
+      AST = ToTy->isSignedIntegerOrEnumerationType()
+                ? Z3_mk_fpa_to_sbv(Z3Context::ZC, RoundingMode.AST, Exp.AST,
+                                   ToBitWidth)
+                : Z3_mk_fpa_to_ubv(Z3Context::ZC, RoundingMode.AST, Exp.AST,
+                                   ToBitWidth);
+    } else {
+      llvm_unreachable("Unsupported explicit type cast!");
+    }
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a boolean, given a Z3_context.
+  static Z3Expr fromBoolean(const bool Bool) {
+    Z3_ast AST = Bool ? Z3_mk_true(Z3Context::ZC) : Z3_mk_false(Z3Context::ZC);
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from a finite APFloat, given a Z3_context.
+  static Z3Expr fromAPFloat(const llvm::APFloat &Float) {
+    Z3_ast AST;
+    Z3Sort Sort = Z3Sort::getFloatSort(
+        llvm::APFloat::semanticsSizeInBits(Float.getSemantics()));
+
+    llvm::APSInt Int = llvm::APSInt(Float.bitcastToAPInt(), true);
+    Z3Expr Z3Int = Z3Expr::fromAPSInt(Int);
+    AST = Z3_mk_fpa_to_fp_bv(Z3Context::ZC, Z3Int.AST, Sort.Sort);
+
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from an APSInt, given a Z3_context.
+  static Z3Expr fromAPSInt(const llvm::APSInt &Int) {
+    Z3Sort Sort = Z3Sort::getBitvectorSort(Int.getBitWidth());
+    Z3_ast AST =
+        Z3_mk_numeral(Z3Context::ZC, Int.toString(10).c_str(), Sort.Sort);
+    return Z3Expr(AST);
+  }
+
+  /// Construct a Z3Expr from an integer, given a Z3_context.
+  static Z3Expr fromInt(const char *Int, uint64_t BitWidth) {
+    Z3Sort Sort = Z3Sort::getBitvectorSort(BitWidth);
+    Z3_ast AST = Z3_mk_numeral(Z3Context::ZC, Int, Sort.Sort);
+    return Z3Expr(AST);
+  }
+
+  /// Construct an APFloat from a Z3Expr, given the AST representation
+  static bool toAPFloat(const Z3Sort &Sort, const Z3_ast &AST,
+                        llvm::APFloat &Float, bool useSemantics = true) {
+    assert(Sort.getSortKind() == Z3_FLOATING_POINT_SORT &&
+           "Unsupported sort to floating-point!");
+
+    llvm::APSInt Int(Sort.getFloatSortSize(), true);
+    const llvm::fltSemantics &Semantics =
+        Z3Expr::getFloatSemantics(Sort.getFloatSortSize());
+    Z3Sort BVSort = Z3Sort::getBitvectorSort(Sort.getFloatSortSize());
+    if (!Z3Expr::toAPSInt(BVSort, AST, Int, true)) {
+      return false;
+    }
+
+    if (useSemantics &&
+        !Z3Expr::areEquivalent(Float.getSemantics(), Semantics)) {
+      assert(false && "Floating-point types don't match!");
+      return false;
+    }
+
+    Float = llvm::APFloat(Semantics, Int);
+    return true;
+  }
+
+  /// Construct an APSInt from a Z3Expr, given the AST representation
+  static bool toAPSInt(const Z3Sort &Sort, const Z3_ast &AST, llvm::APSInt &Int,
+                       bool useSemantics = true) {
+    switch (Sort.getSortKind()) {
+    default:
+      llvm_unreachable("Unsupported sort to integer!");
+    case Z3_BV_SORT: {
+      if (useSemantics && Int.getBitWidth() != Sort.getBitvectorSortSize()) {
+        assert(false && "Bitvector types don't match!");
+        return false;
+      }
+
+      uint64_t Value[2];
+      // Force cast because Z3 defines __uint64 to be a unsigned long long
+      // type, which isn't compatible with a unsigned long type, even if they
+      // are the same size.
+      Z3_get_numeral_uint64(Z3Context::ZC, AST,
+                            reinterpret_cast<__uint64 *>(&Value[0]));
+      if (Sort.getBitvectorSortSize() <= 64) {
+        Int = llvm::APSInt(llvm::APInt(Int.getBitWidth(), Value[0]), true);
+      } else if (Sort.getBitvectorSortSize() == 128) {
+        Z3Expr ASTHigh = Z3Expr(Z3_mk_extract(Z3Context::ZC, 127, 64, AST));
+        Z3_get_numeral_uint64(Z3Context::ZC, AST,
+                              reinterpret_cast<__uint64 *>(&Value[1]));
+        Int = llvm::APSInt(llvm::APInt(Int.getBitWidth(), Value), true);
+      } else {
+        assert(false && "Bitwidth not supported!");
+        return false;
+      }
+      return true;
+    }
+    case Z3_BOOL_SORT:
+      if (useSemantics && Int.getBitWidth() < 1) {
+        assert(false && "Boolean type doesn't match!");
+        return false;
+      }
+      Int = llvm::APSInt(
+          llvm::APInt(Int.getBitWidth(),
+                      Z3_get_bool_value(Z3Context::ZC, AST) == Z3_L_TRUE ? 1
+                                                                         : 0),
+          true);
+      return true;
+    }
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    ID.AddInteger(Z3_get_ast_hash(Z3Context::ZC, AST));
+  }
+
+  bool operator<(const Z3Expr &Other) const {
+    llvm::FoldingSetNodeID ID1, ID2;
+    Profile(ID1);
+    Other.Profile(ID2);
+    return ID1 < ID2;
+  }
+
+  /// Comparison of AST equality, not model equivalence.
+  bool operator==(const Z3Expr &Other) const {
+    assert(Z3_is_eq_sort(Z3Context::ZC, Z3_get_sort(Z3Context::ZC, AST),
+                         Z3_get_sort(Z3Context::ZC, Other.AST)) &&
+           "AST's must have the same sort");
+    return Z3_is_eq_ast(Z3Context::ZC, AST, Other.AST);
+  }
+
+  /// Override implicit move constructor for correct reference counting.
+  Z3Expr &operator=(const Z3Expr &Move) {
+    Z3_inc_ref(Z3Context::ZC, Move.AST);
+    Z3_dec_ref(Z3Context::ZC, AST);
+    AST = Move.AST;
+    return *this;
+  }
+
+  void print(raw_ostream &OS) const {
+    OS << Z3_ast_to_string(Z3Context::ZC, AST);
+  }
+
+  LLVM_DUMP_METHOD void dump() const { print(llvm::errs()); }
+}; // end class Z3Expr
+
+class Z3Model {
+  Z3_model Model;
+
+public:
+  Z3Model(Z3_model ZM) : Model(ZM) { Z3_model_inc_ref(Z3Context::ZC, Model); }
+
+  /// Override implicit copy constructor for correct reference counting.
+  Z3Model(const Z3Model &Copy) : Model(Copy.Model) {
+    Z3_model_inc_ref(Z3Context::ZC, Model);
+  }
+
+  /// Provide move constructor
+  Z3Model(Z3Model &&Move) : Model(nullptr) { *this = std::move(Move); }
+
+  /// Provide move assignment constructor
+  Z3Model &operator=(Z3Model &&Move) {
+    if (this != &Move) {
+      if (Model)
+        Z3_model_dec_ref(Z3Context::ZC, Model);
+      Model = Move.Model;
+      Move.Model = nullptr;
+    }
+    return *this;
+  }
+
+  ~Z3Model() {
+    if (Model)
+      Z3_model_dec_ref(Z3Context::ZC, Model);
+  }
+
+  /// Given an expression, extract the value of this operand in the model.
+  bool getInterpretation(const Z3Expr &Exp, llvm::APSInt &Int) const {
+    Z3_func_decl Func =
+        Z3_get_app_decl(Z3Context::ZC, Z3_to_app(Z3Context::ZC, Exp.AST));
+    if (Z3_model_has_interp(Z3Context::ZC, Model, Func) != Z3_L_TRUE)
+      return false;
+
+    Z3_ast Assign = Z3_model_get_const_interp(Z3Context::ZC, Model, Func);
+    Z3Sort Sort = Z3Sort::getSort(Assign);
+    return Z3Expr::toAPSInt(Sort, Assign, Int, true);
+  }
+
+  /// Given an expression, extract the value of this operand in the model.
+  bool getInterpretation(const Z3Expr &Exp, llvm::APFloat &Float) const {
+    Z3_func_decl Func =
+        Z3_get_app_decl(Z3Context::ZC, Z3_to_app(Z3Context::ZC, Exp.AST));
+    if (Z3_model_has_interp(Z3Context::ZC, Model, Func) != Z3_L_TRUE)
+      return false;
+
+    Z3_ast Assign = Z3_model_get_const_interp(Z3Context::ZC, Model, Func);
+    Z3Sort Sort = Z3Sort::getSort(Assign);
+    return Z3Expr::toAPFloat(Sort, Assign, Float, true);
+  }
+
+  void print(raw_ostream &OS) const {
+    OS << Z3_model_to_string(Z3Context::ZC, Model);
+  }
+
+  LLVM_DUMP_METHOD void dump() const { print(llvm::errs()); }
+}; // end class Z3Model
+
+class Z3Solver {
+  friend class Z3ConstraintManager;
+
+  Z3_solver Solver;
+
+  Z3Solver(Z3_solver ZS) : Solver(ZS) {
+    Z3_solver_inc_ref(Z3Context::ZC, Solver);
+  }
+
+public:
+  /// Override implicit copy constructor for correct reference counting.
+  Z3Solver(const Z3Solver &Copy) : Solver(Copy.Solver) {
+    Z3_solver_inc_ref(Z3Context::ZC, Solver);
+  }
+
+  /// Provide move constructor
+  Z3Solver(Z3Solver &&Move) : Solver(nullptr) { *this = std::move(Move); }
+
+  /// Provide move assignment constructor
+  Z3Solver &operator=(Z3Solver &&Move) {
+    if (this != &Move) {
+      if (Solver)
+        Z3_solver_dec_ref(Z3Context::ZC, Solver);
+      Solver = Move.Solver;
+      Move.Solver = nullptr;
+    }
+    return *this;
+  }
+
+  ~Z3Solver() {
+    if (Solver)
+      Z3_solver_dec_ref(Z3Context::ZC, Solver);
+  }
+
+  /// Given a constraint, add it to the solver
+  void addConstraint(const Z3Expr &Exp) {
+    Z3_solver_assert(Z3Context::ZC, Solver, Exp.AST);
+  }
+
+  /// Given a program state, construct the logical conjunction and add it to
+  /// the solver
+  void addStateConstraints(ProgramStateRef State) {
+    // TODO: Don't add all the constraints, only the relevant ones
+    ConstraintZ3Ty CZ = State->get<ConstraintZ3>();
+    ConstraintZ3Ty::iterator I = CZ.begin(), IE = CZ.end();
+
+    // Construct the logical AND of all the constraints
+    if (I != IE) {
+      std::vector<Z3_ast> ASTs;
+
+      while (I != IE)
+        ASTs.push_back(I++->second.AST);
+
+      Z3Expr Conj = Z3Expr::fromNBinOp(BO_LAnd, ASTs);
+      addConstraint(Conj);
+    }
+  }
+
+  /// Check if the constraints are satisfiable
+  Z3_lbool check() { return Z3_solver_check(Z3Context::ZC, Solver); }
+
+  /// Push the current solver state
+  void push() { return Z3_solver_push(Z3Context::ZC, Solver); }
+
+  /// Pop the previous solver state
+  void pop(unsigned NumStates = 1) {
+    assert(Z3_solver_get_num_scopes(Z3Context::ZC, Solver) >= NumStates);
+    return Z3_solver_pop(Z3Context::ZC, Solver, NumStates);
+  }
+
+  /// Get a model from the solver. Caller should check the model is
+  /// satisfiable.
+  Z3Model getModel() {
+    return Z3Model(Z3_solver_get_model(Z3Context::ZC, Solver));
+  }
+
+  /// Reset the solver and remove all constraints.
+  void reset() { Z3_solver_reset(Z3Context::ZC, Solver); }
+}; // end class Z3Solver
+
+void Z3ErrorHandler(Z3_context Context, Z3_error_code Error) {
+  llvm::report_fatal_error("Z3 error: " +
+                           llvm::Twine(Z3_get_error_msg_ex(Context, Error)));
+}
+
+class Z3ConstraintManager : public SimpleConstraintManager {
+  Z3Context Context;
+  mutable Z3Solver Solver;
+
+public:
+  Z3ConstraintManager(SubEngine *SE, SValBuilder &SB)
+      : SimpleConstraintManager(SE, SB),
+        Solver(Z3_mk_simple_solver(Z3Context::ZC)) {
+    Z3_set_error_handler(Z3Context::ZC, Z3ErrorHandler);
+  }
+
+  //===------------------------------------------------------------------===//
+  // Implementation for interface from ConstraintManager.
+  //===------------------------------------------------------------------===//
+
+  bool canReasonAbout(SVal X) const override;
+
+  ConditionTruthVal checkNull(ProgramStateRef State, SymbolRef Sym) override;
+
+  const llvm::APSInt *getSymVal(ProgramStateRef State,
+                                SymbolRef Sym) const override;
+
+  ProgramStateRef removeDeadBindings(ProgramStateRef St,
+                                     SymbolReaper &SymReaper) override;
+
+  void print(ProgramStateRef St, raw_ostream &Out, const char *nl,
+             const char *sep) override;
+
+  //===------------------------------------------------------------------===//
+  // Implementation for interface from SimpleConstraintManager.
+  //===------------------------------------------------------------------===//
+
+  ProgramStateRef assumeSym(ProgramStateRef state, SymbolRef Sym,
+                            bool Assumption) override;
+
+  ProgramStateRef assumeSymInclusiveRange(ProgramStateRef State, SymbolRef Sym,
+                                          const llvm::APSInt &From,
+                                          const llvm::APSInt &To,
+                                          bool InRange) override;
+
+  ProgramStateRef assumeSymUnsupported(ProgramStateRef State, SymbolRef Sym,
+                                       bool Assumption) override;
+
+private:
+  //===------------------------------------------------------------------===//
+  // Internal implementation.
+  //===------------------------------------------------------------------===//
+
+  // Check whether a new model is satisfiable, and update the program state.
+  ProgramStateRef assumeZ3Expr(ProgramStateRef State, SymbolRef Sym,
+                               const Z3Expr &Exp);
+
+  // Generate and check a Z3 model, using the given constraint.
+  Z3_lbool checkZ3Model(ProgramStateRef State, const Z3Expr &Exp) const;
+
+  // Generate a Z3Expr that represents the given symbolic expression.
+  // Sets the hasComparison parameter if the expression has a comparison
+  // operator.
+  // Sets the RetTy parameter to the final return type after promotions and
+  // casts.
+  Z3Expr getZ3Expr(SymbolRef Sym, QualType *RetTy = nullptr,
+                   bool *hasComparison = nullptr) const;
+
+  // Generate a Z3Expr that takes the logical not of an expression.
+  Z3Expr getZ3NotExpr(const Z3Expr &Exp) const;
+
+  // Generate a Z3Expr that compares the expression to zero.
+  Z3Expr getZ3ZeroExpr(const Z3Expr &Exp, QualType RetTy,
+                       bool Assumption) const;
+
+  // Recursive implementation to unpack and generate symbolic expression.
+  // Sets the hasComparison and RetTy parameters. See getZ3Expr().
+  Z3Expr getZ3SymExpr(SymbolRef Sym, QualType *RetTy,
+                      bool *hasComparison) const;
+
+  // Wrapper to generate Z3Expr from SymbolData.
+  Z3Expr getZ3DataExpr(const SymbolID ID, QualType Ty) const;
+
+  // Wrapper to generate Z3Expr from SymbolCast.
+  Z3Expr getZ3CastExpr(const Z3Expr &Exp, QualType FromTy, QualType Ty) const;
+
+  // Wrapper to generate Z3Expr from BinarySymExpr.
+  // Sets the hasComparison and RetTy parameters. See getZ3Expr().
+  Z3Expr getZ3SymBinExpr(const BinarySymExpr *BSE, bool *hasComparison,
+                         QualType *RetTy) const;
+
+  // Wrapper to generate Z3Expr from unpacked binary symbolic expression.
+  // Sets the RetTy parameter. See getZ3Expr().
+  Z3Expr getZ3BinExpr(const Z3Expr &LHS, QualType LTy,
+                      BinaryOperator::Opcode Op, const Z3Expr &RHS,
+                      QualType RTy, QualType *RetTy) const;
+
+  //===------------------------------------------------------------------===//
+  // Helper functions.
+  //===------------------------------------------------------------------===//
+
+  // Recover the QualType of an APSInt.
+  // TODO: Refactor to put elsewhere
+  QualType getAPSIntType(const llvm::APSInt &Int) const;
+
+  // Perform implicit type conversion on binary symbolic expressions.
+  // May modify all input parameters.
+  // TODO: Refactor to use built-in conversion functions
+  void doTypeConversion(Z3Expr &LHS, Z3Expr &RHS, QualType &LTy,
+                        QualType &RTy) const;
+
+  // Perform implicit integer type conversion.
+  // May modify all input parameters.
+  // TODO: Refactor to use Sema::handleIntegerConversion()
+  template <typename T,
+            T(doCast)(const T &, QualType, uint64_t, QualType, uint64_t)>
+  void doIntTypeConversion(T &LHS, QualType &LTy, T &RHS, QualType &RTy) const;
+
+  // Perform implicit floating-point type conversion.
+  // May modify all input parameters.
+  // TODO: Refactor to use Sema::handleFloatConversion()
+  template <typename T,
+            T(doCast)(const T &, QualType, uint64_t, QualType, uint64_t)>
+  void doFloatTypeConversion(T &LHS, QualType &LTy, T &RHS,
+                             QualType &RTy) const;
+
+  // Callback function for doCast parameter on APSInt type.
+  static llvm::APSInt castAPSInt(const llvm::APSInt &V, QualType ToTy,
+                                 uint64_t ToWidth, QualType FromTy,
+                                 uint64_t FromWidth);
+}; // end class Z3ConstraintManager
+
+Z3_context Z3Context::ZC;
+
+} // end anonymous namespace
+
+ProgramStateRef Z3ConstraintManager::assumeSym(ProgramStateRef State,
+                                               SymbolRef Sym, bool Assumption) {
+  QualType RetTy;
+  bool hasComparison;
+
+  Z3Expr Exp = getZ3Expr(Sym, &RetTy, &hasComparison);
+  // Create zero comparison for implicit boolean cast, with reversed assumption
+  if (!hasComparison && !RetTy->isBooleanType())
+    return assumeZ3Expr(State, Sym, getZ3ZeroExpr(Exp, RetTy, !Assumption));
+
+  return assumeZ3Expr(State, Sym, Assumption ? Exp : getZ3NotExpr(Exp));
+}
+
+ProgramStateRef Z3ConstraintManager::assumeSymInclusiveRange(
+    ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
+    const llvm::APSInt &To, bool InRange) {
+  QualType RetTy;
+  // The expression may be casted, so we cannot call getZ3DataExpr() directly
+  Z3Expr Exp = getZ3Expr(Sym, &RetTy);
+
+  assert((getAPSIntType(From) == getAPSIntType(To)) &&
+         "Range values have different types!");
+  QualType RTy = getAPSIntType(From);
+  bool isSignedTy = RetTy->isSignedIntegerOrEnumerationType();
+  Z3Expr FromExp = Z3Expr::fromAPSInt(From);
+  Z3Expr ToExp = Z3Expr::fromAPSInt(To);
+
+  // Construct single (in)equality
+  if (From == To)
+    return assumeZ3Expr(State, Sym,
+                        getZ3BinExpr(Exp, RetTy, InRange ? BO_EQ : BO_NE,
+                                     FromExp, RTy, nullptr));
+
+  // Construct two (in)equalities, and a logical and/or
+  Z3Expr LHS =
+      getZ3BinExpr(Exp, RetTy, InRange ? BO_GE : BO_LT, FromExp, RTy, nullptr);
+  Z3Expr RHS =
+      getZ3BinExpr(Exp, RetTy, InRange ? BO_LE : BO_GT, ToExp, RTy, nullptr);
+  return assumeZ3Expr(
+      State, Sym,
+      Z3Expr::fromBinOp(LHS, InRange ? BO_LAnd : BO_LOr, RHS, isSignedTy));
+}
+
+ProgramStateRef Z3ConstraintManager::assumeSymUnsupported(ProgramStateRef State,
+                                                          SymbolRef Sym,
+                                                          bool Assumption) {
+  // Skip anything that is unsupported
+  return State;
+}
+
+bool Z3ConstraintManager::canReasonAbout(SVal X) const {
+  const TargetInfo &TI = getBasicVals().getContext().getTargetInfo();
+
+  Optional<nonloc::SymbolVal> SymVal = X.getAs<nonloc::SymbolVal>();
+  if (!SymVal)
+    return true;
+
+  const SymExpr *Sym = SymVal->getSymbol();
+  do {
+    QualType Ty = Sym->getType();
+
+    // Complex types are not modeled
+    if (Ty->isComplexType() || Ty->isComplexIntegerType())
+      return false;
+
+    // Non-IEEE 754 floating-point types are not modeled
+    if ((Ty->isSpecificBuiltinType(BuiltinType::LongDouble) &&
+         (&TI.getLongDoubleFormat() == &llvm::APFloat::x87DoubleExtended() ||
+          &TI.getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble())))
+      return false;
+
+    if (isa<SymbolData>(Sym)) {
+      break;
+    } else if (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) {
+      Sym = SC->getOperand();
+    } else if (const BinarySymExpr *BSE = dyn_cast<BinarySymExpr>(Sym)) {
+      if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(BSE)) {
+        Sym = SIE->getLHS();
+      } else if (const IntSymExpr *ISE = dyn_cast<IntSymExpr>(BSE)) {
+        Sym = ISE->getRHS();
+      } else if (const SymSymExpr *SSM = dyn_cast<SymSymExpr>(BSE)) {
+        return canReasonAbout(nonloc::SymbolVal(SSM->getLHS())) &&
+               canReasonAbout(nonloc::SymbolVal(SSM->getRHS()));
+      } else {
+        llvm_unreachable("Unsupported binary expression to reason about!");
+      }
+    } else {
+      llvm_unreachable("Unsupported expression to reason about!");
+    }
+  } while (Sym);
+
+  return true;
+}
+
+ConditionTruthVal Z3ConstraintManager::checkNull(ProgramStateRef State,
+                                                 SymbolRef Sym) {
+  QualType RetTy;
+  // The expression may be casted, so we cannot call getZ3DataExpr() directly
+  Z3Expr VarExp = getZ3Expr(Sym, &RetTy);
+  Z3Expr Exp = getZ3ZeroExpr(VarExp, RetTy, true);
+  // Negate the constraint
+  Z3Expr NotExp = getZ3ZeroExpr(VarExp, RetTy, false);
+
+  Solver.reset();
+  Solver.addStateConstraints(State);
+
+  Solver.push();
+  Solver.addConstraint(Exp);
+  Z3_lbool isSat = Solver.check();
+
+  Solver.pop();
+  Solver.addConstraint(NotExp);
+  Z3_lbool isNotSat = Solver.check();
+
+  // Zero is the only possible solution
+  if (isSat == Z3_L_TRUE && isNotSat == Z3_L_FALSE)
+    return true;
+  // Zero is not a solution
+  else if (isSat == Z3_L_FALSE && isNotSat == Z3_L_TRUE)
+    return false;
+
+  // Zero may be a solution
+  return ConditionTruthVal();
+}
+
+const llvm::APSInt *Z3ConstraintManager::getSymVal(ProgramStateRef State,
+                                                   SymbolRef Sym) const {
+  BasicValueFactory &BV = getBasicVals();
+  ASTContext &Ctx = BV.getContext();
+
+  if (const SymbolData *SD = dyn_cast<SymbolData>(Sym)) {
+    QualType Ty = Sym->getType();
+    assert(!Ty->isRealFloatingType());
+    llvm::APSInt Value(Ctx.getTypeSize(Ty),
+                       !Ty->isSignedIntegerOrEnumerationType());
+
+    Z3Expr Exp = getZ3DataExpr(SD->getSymbolID(), Ty);
+
+    Solver.reset();
+    Solver.addStateConstraints(State);
+
+    // Constraints are unsatisfiable
+    if (Solver.check() != Z3_L_TRUE)
+      return nullptr;
+
+    Z3Model Model = Solver.getModel();
+    // Model does not assign interpretation
+    if (!Model.getInterpretation(Exp, Value))
+      return nullptr;
+
+    // A value has been obtained, check if it is the only value
+    Z3Expr NotExp = Z3Expr::fromBinOp(
+        Exp, BO_NE,
+        Ty->isBooleanType() ? Z3Expr::fromBoolean(Value.getBoolValue())
+                            : Z3Expr::fromAPSInt(Value),
+        false);
+
+    Solver.addConstraint(NotExp);
+    if (Solver.check() == Z3_L_TRUE)
+      return nullptr;
+
+    // This is the only solution, store it
+    return &BV.getValue(Value);
+  } else if (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) {
+    SymbolRef CastSym = SC->getOperand();
+    QualType CastTy = SC->getType();
+    // Skip the void type
+    if (CastTy->isVoidType())
+      return nullptr;
+
+    const llvm::APSInt *Value;
+    if (!(Value = getSymVal(State, CastSym)))
+      return nullptr;
+    return &BV.Convert(SC->getType(), *Value);
+  } else if (const BinarySymExpr *BSE = dyn_cast<BinarySymExpr>(Sym)) {
+    const llvm::APSInt *LHS, *RHS;
+    if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(BSE)) {
+      LHS = getSymVal(State, SIE->getLHS());
+      RHS = &SIE->getRHS();
+    } else if (const IntSymExpr *ISE = dyn_cast<IntSymExpr>(BSE)) {
+      LHS = &ISE->getLHS();
+      RHS = getSymVal(State, ISE->getRHS());
+    } else if (const SymSymExpr *SSM = dyn_cast<SymSymExpr>(BSE)) {
+      // Early termination to avoid expensive call
+      LHS = getSymVal(State, SSM->getLHS());
+      RHS = LHS ? getSymVal(State, SSM->getRHS()) : nullptr;
+    } else {
+      llvm_unreachable("Unsupported binary expression to get symbol value!");
+    }
+
+    if (!LHS || !RHS)
+      return nullptr;
+
+    llvm::APSInt ConvertedLHS = *LHS, ConvertedRHS = *RHS;
+    QualType LTy = getAPSIntType(*LHS), RTy = getAPSIntType(*RHS);
+    doIntTypeConversion<llvm::APSInt, Z3ConstraintManager::castAPSInt>(
+        ConvertedLHS, LTy, ConvertedRHS, RTy);
+    return BV.evalAPSInt(BSE->getOpcode(), ConvertedLHS, ConvertedRHS);
+  }
+
+  llvm_unreachable("Unsupported expression to get symbol value!");
+}
+
+ProgramStateRef
+Z3ConstraintManager::removeDeadBindings(ProgramStateRef State,
+                                        SymbolReaper &SymReaper) {
+  ConstraintZ3Ty CZ = State->get<ConstraintZ3>();
+  ConstraintZ3Ty::Factory &CZFactory = State->get_context<ConstraintZ3>();
+
+  for (ConstraintZ3Ty::iterator I = CZ.begin(), E = CZ.end(); I != E; ++I) {
+    if (SymReaper.maybeDead(I->first))
+      CZ = CZFactory.remove(CZ, *I);
+  }
+
+  return State->set<ConstraintZ3>(CZ);
+}
+
+//===------------------------------------------------------------------===//
+// Internal implementation.
+//===------------------------------------------------------------------===//
+
+ProgramStateRef Z3ConstraintManager::assumeZ3Expr(ProgramStateRef State,
+                                                  SymbolRef Sym,
+                                                  const Z3Expr &Exp) {
+  // Check the model, avoid simplifying AST to save time
+  if (checkZ3Model(State, Exp) == Z3_L_TRUE)
+    return State->add<ConstraintZ3>(std::make_pair(Sym, Exp));
+
+  return nullptr;
+}
+
+Z3_lbool Z3ConstraintManager::checkZ3Model(ProgramStateRef State,
+                                           const Z3Expr &Exp) const {
+  Solver.reset();
+  Solver.addConstraint(Exp);
+  Solver.addStateConstraints(State);
+  return Solver.check();
+}
+
+Z3Expr Z3ConstraintManager::getZ3Expr(SymbolRef Sym, QualType *RetTy,
+                                      bool *hasComparison) const {
+  if (hasComparison) {
+    *hasComparison = false;
+  }
+
+  return getZ3SymExpr(Sym, RetTy, hasComparison);
+}
+
+Z3Expr Z3ConstraintManager::getZ3NotExpr(const Z3Expr &Exp) const {
+  return Z3Expr::fromUnOp(UO_LNot, Exp);
+}
+
+Z3Expr Z3ConstraintManager::getZ3ZeroExpr(const Z3Expr &Exp, QualType Ty,
+                                          bool Assumption) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+  if (Ty->isRealFloatingType()) {
+    llvm::APFloat Zero = llvm::APFloat::getZero(Ctx.getFloatTypeSemantics(Ty));
+    return Z3Expr::fromFloatBinOp(Exp, Assumption ? BO_EQ : BO_NE,
+                                  Z3Expr::fromAPFloat(Zero));
+  } else if (Ty->isIntegralOrEnumerationType() || Ty->isAnyPointerType() ||
+             Ty->isBlockPointerType() || Ty->isReferenceType()) {
+    bool isSigned = Ty->isSignedIntegerOrEnumerationType();
+    // Skip explicit comparison for boolean types
+    if (Ty->isBooleanType())
+      return Assumption ? getZ3NotExpr(Exp) : Exp;
+    return Z3Expr::fromBinOp(Exp, Assumption ? BO_EQ : BO_NE,
+                             Z3Expr::fromInt("0", Ctx.getTypeSize(Ty)),
+                             isSigned);
+  }
+
+  llvm_unreachable("Unsupported type for zero value!");
+}
+
+Z3Expr Z3ConstraintManager::getZ3SymExpr(SymbolRef Sym, QualType *RetTy,
+                                         bool *hasComparison) const {
+  if (const SymbolData *SD = dyn_cast<SymbolData>(Sym)) {
+    if (RetTy)
+      *RetTy = Sym->getType();
+
+    return getZ3DataExpr(SD->getSymbolID(), Sym->getType());
+  } else if (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) {
+    if (RetTy)
+      *RetTy = Sym->getType();
+
+    QualType FromTy;
+    Z3Expr Exp = getZ3SymExpr(SC->getOperand(), &FromTy, hasComparison);
+    // Casting an expression with a comparison invalidates it. Note that this
+    // must occur after the recursive call above.
+    // e.g. (signed char) (x > 0)
+    if (hasComparison)
+      *hasComparison = false;
+    return getZ3CastExpr(Exp, FromTy, Sym->getType());
+  } else if (const BinarySymExpr *BSE = dyn_cast<BinarySymExpr>(Sym)) {
+    Z3Expr Exp = getZ3SymBinExpr(BSE, hasComparison, RetTy);
+    // Set the hasComparison parameter, in post-order traversal order.
+    if (hasComparison)
+      *hasComparison = BinaryOperator::isComparisonOp(BSE->getOpcode());
+    return Exp;
+  }
+
+  llvm_unreachable("Unsupported SymbolRef type!");
+}
+
+Z3Expr Z3ConstraintManager::getZ3DataExpr(const SymbolID ID,
+                                          QualType Ty) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+  return Z3Expr::fromData(ID, Ty->isBooleanType(), Ty->isRealFloatingType(),
+                          Ctx.getTypeSize(Ty));
+}
+
+Z3Expr Z3ConstraintManager::getZ3CastExpr(const Z3Expr &Exp, QualType FromTy,
+                                          QualType ToTy) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+  return Z3Expr::fromCast(Exp, ToTy, Ctx.getTypeSize(ToTy), FromTy,
+                          Ctx.getTypeSize(FromTy));
+}
+
+Z3Expr Z3ConstraintManager::getZ3SymBinExpr(const BinarySymExpr *BSE,
+                                            bool *hasComparison,
+                                            QualType *RetTy) const {
+  QualType LTy, RTy;
+  BinaryOperator::Opcode Op = BSE->getOpcode();
+
+  if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(BSE)) {
+    RTy = getAPSIntType(SIE->getRHS());
+    Z3Expr LHS = getZ3SymExpr(SIE->getLHS(), &LTy, hasComparison);
+    Z3Expr RHS = Z3Expr::fromAPSInt(SIE->getRHS());
+    return getZ3BinExpr(LHS, LTy, Op, RHS, RTy, RetTy);
+  } else if (const IntSymExpr *ISE = dyn_cast<IntSymExpr>(BSE)) {
+    LTy = getAPSIntType(ISE->getLHS());
+    Z3Expr LHS = Z3Expr::fromAPSInt(ISE->getLHS());
+    Z3Expr RHS = getZ3SymExpr(ISE->getRHS(), &RTy, hasComparison);
+    return getZ3BinExpr(LHS, LTy, Op, RHS, RTy, RetTy);
+  } else if (const SymSymExpr *SSM = dyn_cast<SymSymExpr>(BSE)) {
+    Z3Expr LHS = getZ3SymExpr(SSM->getLHS(), &LTy, hasComparison);
+    Z3Expr RHS = getZ3SymExpr(SSM->getRHS(), &RTy, hasComparison);
+    return getZ3BinExpr(LHS, LTy, Op, RHS, RTy, RetTy);
+  } else {
+    llvm_unreachable("Unsupported BinarySymExpr type!");
+  }
+}
+
+Z3Expr Z3ConstraintManager::getZ3BinExpr(const Z3Expr &LHS, QualType LTy,
+                                         BinaryOperator::Opcode Op,
+                                         const Z3Expr &RHS, QualType RTy,
+                                         QualType *RetTy) const {
+  Z3Expr NewLHS = LHS;
+  Z3Expr NewRHS = RHS;
+  doTypeConversion(NewLHS, NewRHS, LTy, RTy);
+  // Update the return type parameter if the output type has changed.
+  if (RetTy) {
+    // A boolean result can be represented as an integer type in C/C++, but at
+    // this point we only care about the Z3 type. Set it as a boolean type to
+    // avoid subsequent Z3 errors.
+    if (BinaryOperator::isComparisonOp(Op) || BinaryOperator::isLogicalOp(Op)) {
+      ASTContext &Ctx = getBasicVals().getContext();
+      *RetTy = Ctx.BoolTy;
+    } else {
+      *RetTy = LTy;
+    }
+
+    // If the two operands are pointers and the operation is a subtraction, the
+    // result is of type ptrdiff_t, which is signed
+    if (LTy->isAnyPointerType() && LTy == RTy && Op == BO_Sub) {
+      ASTContext &Ctx = getBasicVals().getContext();
+      *RetTy = Ctx.getIntTypeForBitwidth(Ctx.getTypeSize(LTy), true);
+    }
+  }
+
+  return LTy->isRealFloatingType()
+             ? Z3Expr::fromFloatBinOp(NewLHS, Op, NewRHS)
+             : Z3Expr::fromBinOp(NewLHS, Op, NewRHS,
+                                 LTy->isSignedIntegerOrEnumerationType());
+}
+
+//===------------------------------------------------------------------===//
+// Helper functions.
+//===------------------------------------------------------------------===//
+
+QualType Z3ConstraintManager::getAPSIntType(const llvm::APSInt &Int) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+  return Ctx.getIntTypeForBitwidth(Int.getBitWidth(), Int.isSigned());
+}
+
+void Z3ConstraintManager::doTypeConversion(Z3Expr &LHS, Z3Expr &RHS,
+                                           QualType &LTy, QualType &RTy) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+
+  // Perform type conversion
+  if (LTy->isIntegralOrEnumerationType() &&
+      RTy->isIntegralOrEnumerationType()) {
+    if (LTy->isArithmeticType() && RTy->isArithmeticType())
+      return doIntTypeConversion<Z3Expr, Z3Expr::fromCast>(LHS, LTy, RHS, RTy);
+  } else if (LTy->isRealFloatingType() || RTy->isRealFloatingType()) {
+    return doFloatTypeConversion<Z3Expr, Z3Expr::fromCast>(LHS, LTy, RHS, RTy);
+  } else if ((LTy->isAnyPointerType() || RTy->isAnyPointerType()) ||
+             (LTy->isBlockPointerType() || RTy->isBlockPointerType()) ||
+             (LTy->isReferenceType() || RTy->isReferenceType())) {
+    // TODO: Refactor to Sema::FindCompositePointerType(), and
+    // Sema::CheckCompareOperands().
+
+    uint64_t LBitWidth = Ctx.getTypeSize(LTy);
+    uint64_t RBitWidth = Ctx.getTypeSize(RTy);
+
+    // Cast the non-pointer type to the pointer type.
+    // TODO: Be more strict about this.
+    if ((LTy->isAnyPointerType() ^ RTy->isAnyPointerType()) ||
+        (LTy->isBlockPointerType() ^ RTy->isBlockPointerType()) ||
+        (LTy->isReferenceType() ^ RTy->isReferenceType())) {
+      if (LTy->isNullPtrType() || LTy->isBlockPointerType() ||
+          LTy->isReferenceType()) {
+        LHS = Z3Expr::fromCast(LHS, RTy, RBitWidth, LTy, LBitWidth);
+        LTy = RTy;
+      } else {
+        RHS = Z3Expr::fromCast(RHS, LTy, LBitWidth, RTy, RBitWidth);
+        RTy = LTy;
+      }
+    }
+
+    // Cast the void pointer type to the non-void pointer type.
+    // For void types, this assumes that the casted value is equal to the value
+    // of the original pointer, and does not account for alignment requirements.
+    if (LTy->isVoidPointerType() ^ RTy->isVoidPointerType()) {
+      assert((Ctx.getTypeSize(LTy) == Ctx.getTypeSize(RTy)) &&
+             "Pointer types have different bitwidths!");
+      if (RTy->isVoidPointerType())
+        RTy = LTy;
+      else
+        LTy = RTy;
+    }
+
+    if (LTy == RTy)
+      return;
+  }
+
+  // Fallback: for the solver, assume that these types don't really matter
+  if ((LTy.getCanonicalType() == RTy.getCanonicalType()) ||
+      (LTy->isObjCObjectPointerType() && RTy->isObjCObjectPointerType())) {
+    LTy = RTy;
+    return;
+  }
+
+  // TODO: Refine behavior for invalid type casts
+}
+
+template <typename T,
+          T(doCast)(const T &, QualType, uint64_t, QualType, uint64_t)>
+void Z3ConstraintManager::doIntTypeConversion(T &LHS, QualType &LTy, T &RHS,
+                                              QualType &RTy) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+
+  uint64_t LBitWidth = Ctx.getTypeSize(LTy);
+  uint64_t RBitWidth = Ctx.getTypeSize(RTy);
+
+  // Always perform integer promotion before checking type equality.
+  // Otherwise, e.g. (bool) a + (bool) b could trigger a backend assertion
+  if (LTy->isPromotableIntegerType()) {
+    QualType NewTy = Ctx.getPromotedIntegerType(LTy);
+    uint64_t NewBitWidth = Ctx.getTypeSize(NewTy);
+    LHS = (*doCast)(LHS, NewTy, NewBitWidth, LTy, LBitWidth);
+    LTy = NewTy;
+    LBitWidth = NewBitWidth;
+  }
+  if (RTy->isPromotableIntegerType()) {
+    QualType NewTy = Ctx.getPromotedIntegerType(RTy);
+    uint64_t NewBitWidth = Ctx.getTypeSize(NewTy);
+    RHS = (*doCast)(RHS, NewTy, NewBitWidth, RTy, RBitWidth);
+    RTy = NewTy;
+    RBitWidth = NewBitWidth;
+  }
+
+  if (LTy == RTy)
+    return;
+
+  // Perform integer type conversion
+  // Note: Safe to skip updating bitwidth because this must terminate
+  bool isLSignedTy = LTy->isSignedIntegerOrEnumerationType();
+  bool isRSignedTy = RTy->isSignedIntegerOrEnumerationType();
+
+  int order = Ctx.getIntegerTypeOrder(LTy, RTy);
+  if (isLSignedTy == isRSignedTy) {
+    // Same signedness; use the higher-ranked type
+    if (order == 1) {
+      RHS = (*doCast)(RHS, LTy, LBitWidth, RTy, RBitWidth);
+      RTy = LTy;
+    } else {
+      LHS = (*doCast)(LHS, RTy, RBitWidth, LTy, LBitWidth);
+      LTy = RTy;
+    }
+  } else if (order != (isLSignedTy ? 1 : -1)) {
+    // The unsigned type has greater than or equal rank to the
+    // signed type, so use the unsigned type
+    if (isRSignedTy) {
+      RHS = (*doCast)(RHS, LTy, LBitWidth, RTy, RBitWidth);
+      RTy = LTy;
+    } else {
+      LHS = (*doCast)(LHS, RTy, RBitWidth, LTy, LBitWidth);
+      LTy = RTy;
+    }
+  } else if (LBitWidth != RBitWidth) {
+    // The two types are different widths; if we are here, that
+    // means the signed type is larger than the unsigned type, so
+    // use the signed type.
+    if (isLSignedTy) {
+      RHS = (*doCast)(RHS, LTy, LBitWidth, RTy, RBitWidth);
+      RTy = LTy;
+    } else {
+      LHS = (*doCast)(LHS, RTy, RBitWidth, LTy, LBitWidth);
+      LTy = RTy;
+    }
+  } else {
+    // The signed type is higher-ranked than the unsigned type,
+    // but isn't actually any bigger (like unsigned int and long
+    // on most 32-bit systems).  Use the unsigned type corresponding
+    // to the signed type.
+    QualType NewTy = Ctx.getCorrespondingUnsignedType(isLSignedTy ? LTy : RTy);
+    RHS = (*doCast)(RHS, LTy, LBitWidth, RTy, RBitWidth);
+    RTy = NewTy;
+    LHS = (*doCast)(LHS, RTy, RBitWidth, LTy, LBitWidth);
+    LTy = NewTy;
+  }
+}
+
+template <typename T,
+          T(doCast)(const T &, QualType, uint64_t, QualType, uint64_t)>
+void Z3ConstraintManager::doFloatTypeConversion(T &LHS, QualType &LTy, T &RHS,
+                                                QualType &RTy) const {
+  ASTContext &Ctx = getBasicVals().getContext();
+
+  uint64_t LBitWidth = Ctx.getTypeSize(LTy);
+  uint64_t RBitWidth = Ctx.getTypeSize(RTy);
+
+  // Perform float-point type promotion
+  if (!LTy->isRealFloatingType()) {
+    LHS = (*doCast)(LHS, RTy, RBitWidth, LTy, LBitWidth);
+    LTy = RTy;
+    LBitWidth = RBitWidth;
+  }
+  if (!RTy->isRealFloatingType()) {
+    RHS = (*doCast)(RHS, LTy, LBitWidth, RTy, RBitWidth);
+    RTy = LTy;
+    RBitWidth = LBitWidth;
+  }
+
+  if (LTy == RTy)
+    return;
+
+  // If we have two real floating types, convert the smaller operand to the
+  // bigger result
+  // Note: Safe to skip updating bitwidth because this must terminate
+  int order = Ctx.getFloatingTypeOrder(LTy, RTy);
+  if (order > 0) {
+    RHS = Z3Expr::fromCast(RHS, LTy, LBitWidth, RTy, RBitWidth);
+    RTy = LTy;
+  } else if (order == 0) {
+    LHS = Z3Expr::fromCast(LHS, RTy, RBitWidth, LTy, LBitWidth);
+    LTy = RTy;
+  } else {
+    llvm_unreachable("Unsupported floating-point type cast!");
+  }
+}
+
+llvm::APSInt Z3ConstraintManager::castAPSInt(const llvm::APSInt &V,
+                                             QualType ToTy, uint64_t ToWidth,
+                                             QualType FromTy,
+                                             uint64_t FromWidth) {
+  APSIntType TargetType(ToWidth, !ToTy->isSignedIntegerOrEnumerationType());
+  return TargetType.convert(V);
+}
+
+//==------------------------------------------------------------------------==/
+// Pretty-printing.
+//==------------------------------------------------------------------------==/
+
+void Z3ConstraintManager::print(ProgramStateRef St, raw_ostream &OS,
+                                const char *nl, const char *sep) {
+
+  ConstraintZ3Ty CZ = St->get<ConstraintZ3>();
+
+  OS << nl << sep << "Constraints:";
+  for (ConstraintZ3Ty::iterator I = CZ.begin(), E = CZ.end(); I != E; ++I) {
+    OS << nl << ' ' << I->first << " : ";
+    I->second.print(OS);
+  }
+  OS << nl;
+}
+
+#endif
+
+std::unique_ptr<ConstraintManager>
+ento::CreateZ3ConstraintManager(ProgramStateManager &StMgr, SubEngine *Eng) {
+#if CLANG_ANALYZER_WITH_Z3
+  return llvm::make_unique<Z3ConstraintManager>(Eng, StMgr.getSValBuilder());
+#else
+  llvm::report_fatal_error("Clang was not compiled with Z3 support!", false);
+  return nullptr;
+#endif
+}