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fuchsia / third_party / swift-clang / 62e2a1cff0cffd48650f0249da958e755d09e9a0 / . / lib / StaticAnalyzer / Core / Z3ConstraintManager.cpp
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//== 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
}