SVal GRSimpleVals::EvalCast(GRExprEngine& Eng, Loc X, QualType T) {
// Casts from pointers -> pointers, just return the lval.
//
// Casts from pointers -> references, just return the lval. These
// can be introduced by the frontend for corner cases, e.g
// casting from va_list* to __builtin_va_list&.
//
assert (!X.isUnknownOrUndef());
if (Loc::IsLocType(T) || T->isReferenceType())
return X;
// FIXME: Handle transparent unions where a value can be "transparently"
// lifted into a union type.
if (T->isUnionType())
return UnknownVal();
assert (T->isIntegerType());
BasicValueFactory& BasicVals = Eng.getBasicVals();
unsigned BitWidth = Eng.getContext().getTypeSize(T);
if (!isa<loc::ConcreteInt>(X))
return nonloc::LocAsInteger::Make(BasicVals, X, BitWidth);
llvm::APSInt V = cast<loc::ConcreteInt>(X).getValue();
V.setIsUnsigned(T->isUnsignedIntegerType() || Loc::IsLocType(T));
V.extOrTrunc(BitWidth);
return nonloc::ConcreteInt(BasicVals.getValue(V));
}
SVal GRSimpleVals::EvalBinOp(GRExprEngine& Eng, const GRState *state,
BinaryOperator::Opcode Op, Loc L, NonLoc R) {
// Special case: 'R' is an integer that has the same width as a pointer and
// we are using the integer location in a comparison. Normally this cannot be
// triggered, but transfer functions like those for OSCommpareAndSwapBarrier32
// can generate comparisons that trigger this code.
// FIXME: Are all locations guaranteed to have pointer width?
if (BinaryOperator::isEqualityOp(Op)) {
if (nonloc::ConcreteInt *RInt = dyn_cast<nonloc::ConcreteInt>(&R)) {
const llvm::APSInt *X = &RInt->getValue();
ASTContext &C = Eng.getContext();
if (C.getTypeSize(C.VoidPtrTy) == X->getBitWidth()) {
// Convert the signedness of the integer (if necessary).
if (X->isSigned())
X = &Eng.getBasicVals().getValue(*X, true);
return EvalBinOp(Eng, Op, L, loc::ConcreteInt(*X));
}
}
}
// Delegate pointer arithmetic to store manager.
return Eng.getStoreManager().EvalBinOp(state, Op, L, R);
}
SVal GRSimpleVals::EvalEquality(GRExprEngine& Eng, Loc L, Loc R, bool isEqual) {
BasicValueFactory& BasicVals = Eng.getBasicVals();
switch (L.getSubKind()) {
default:
assert(false && "EQ/NE not implemented for this Loc.");
return UnknownVal();
case loc::ConcreteIntKind:
if (isa<loc::ConcreteInt>(R)) {
bool b = cast<loc::ConcreteInt>(L).getValue() ==
cast<loc::ConcreteInt>(R).getValue();
// Are we computing '!='? Flip the result.
if (!isEqual)
b = !b;
return NonLoc::MakeIntTruthVal(BasicVals, b);
}
else if (SymbolRef Sym = R.getAsSymbol()) {
const SymIntExpr * SE =
Eng.getSymbolManager().getSymIntExpr(Sym,
isEqual ? BinaryOperator::EQ
: BinaryOperator::NE,
cast<loc::ConcreteInt>(L).getValue(),
Eng.getContext().IntTy);
return nonloc::SymExprVal(SE);
}
break;
case loc::MemRegionKind: {
if (SymbolRef LSym = L.getAsLocSymbol()) {
if (isa<loc::ConcreteInt>(R)) {
const SymIntExpr *SE =
Eng.getSymbolManager().getSymIntExpr(LSym,
isEqual ? BinaryOperator::EQ
: BinaryOperator::NE,
cast<loc::ConcreteInt>(R).getValue(),
Eng.getContext().IntTy);
return nonloc::SymExprVal(SE);
}
}
}
// Fall-through.
case loc::GotoLabelKind:
return NonLoc::MakeIntTruthVal(BasicVals, isEqual ? L == R : L != R);
}
return NonLoc::MakeIntTruthVal(BasicVals, isEqual ? false : true);
}
SVal GRSimpleVals::EvalMinus(GRExprEngine& Eng, UnaryOperator* U, NonLoc X){
switch (X.getSubKind()) {
case nonloc::ConcreteIntKind:
return cast<nonloc::ConcreteInt>(X).EvalMinus(Eng.getBasicVals(), U);
default:
return UnknownVal();
}
}
SVal GRSimpleVals::EvalComplement(GRExprEngine& Eng, NonLoc X) {
switch (X.getSubKind()) {
case nonloc::ConcreteIntKind:
return cast<nonloc::ConcreteInt>(X).EvalComplement(Eng.getBasicVals());
default:
return UnknownVal();
}
}
SVal GRSimpleVals::EvalCast(GRExprEngine& Eng, NonLoc X, QualType T) {
if (!isa<nonloc::ConcreteInt>(X))
return UnknownVal();
bool isLocType = Loc::IsLocType(T);
// Only handle casts from integers to integers.
if (!isLocType && !T->isIntegerType())
return UnknownVal();
BasicValueFactory& BasicVals = Eng.getBasicVals();
llvm::APSInt V = cast<nonloc::ConcreteInt>(X).getValue();
V.setIsUnsigned(T->isUnsignedIntegerType() || Loc::IsLocType(T));
V.extOrTrunc(Eng.getContext().getTypeSize(T));
if (isLocType)
return loc::ConcreteInt(BasicVals.getValue(V));
else
return nonloc::ConcreteInt(BasicVals.getValue(V));
}
SVal GRSimpleVals::DetermEvalBinOpNN(GRExprEngine& Eng,
BinaryOperator::Opcode Op,
NonLoc L, NonLoc R,
QualType T) {
BasicValueFactory& BasicVals = Eng.getBasicVals();
unsigned subkind = L.getSubKind();
while (1) {
switch (subkind) {
default:
return UnknownVal();
case nonloc::LocAsIntegerKind: {
Loc LL = cast<nonloc::LocAsInteger>(L).getLoc();
switch (R.getSubKind()) {
case nonloc::LocAsIntegerKind:
return EvalBinOp(Eng, Op, LL,
cast<nonloc::LocAsInteger>(R).getLoc());
case nonloc::ConcreteIntKind: {
// Transform the integer into a location and compare.
ASTContext& Ctx = Eng.getContext();
llvm::APSInt V = cast<nonloc::ConcreteInt>(R).getValue();
V.setIsUnsigned(true);
V.extOrTrunc(Ctx.getTypeSize(Ctx.VoidPtrTy));
return EvalBinOp(Eng, Op, LL,
loc::ConcreteInt(BasicVals.getValue(V)));
}
default:
switch (Op) {
case BinaryOperator::EQ:
return NonLoc::MakeIntTruthVal(BasicVals, false);
case BinaryOperator::NE:
return NonLoc::MakeIntTruthVal(BasicVals, true);
default:
// This case also handles pointer arithmetic.
return UnknownVal();
}
}
}
case nonloc::SymExprValKind: {
// Logical not?
if (!(Op == BinaryOperator::EQ && R.isZeroConstant()))
return UnknownVal();
const SymExpr &SE=*cast<nonloc::SymExprVal>(L).getSymbolicExpression();
// Only handle ($sym op constant) for now.
if (const SymIntExpr *E = dyn_cast<SymIntExpr>(&SE)) {
BinaryOperator::Opcode Opc = E->getOpcode();
if (Opc < BinaryOperator::LT || Opc > BinaryOperator::NE)
return UnknownVal();
// For comparison operators, translate the constraint by
// changing the opcode.
int idx = (unsigned) Opc - (unsigned) BinaryOperator::LT;
assert (idx >= 0 &&
(unsigned) idx < sizeof(LNotOpMap)/sizeof(unsigned char));
Opc = (BinaryOperator::Opcode) LNotOpMap[idx];
assert(E->getType(Eng.getContext()) == T);
E = Eng.getSymbolManager().getSymIntExpr(E->getLHS(), Opc,
E->getRHS(), T);
return nonloc::SymExprVal(E);
}
return UnknownVal();
}
case nonloc::ConcreteIntKind:
if (isa<nonloc::ConcreteInt>(R)) {
const nonloc::ConcreteInt& L_CI = cast<nonloc::ConcreteInt>(L);
const nonloc::ConcreteInt& R_CI = cast<nonloc::ConcreteInt>(R);
return L_CI.EvalBinOp(BasicVals, Op, R_CI);
}
else {
subkind = R.getSubKind();
NonLoc tmp = R;
R = L;
L = tmp;
// Swap the operators.
switch (Op) {
case BinaryOperator::LT: Op = BinaryOperator::GT; break;
case BinaryOperator::GT: Op = BinaryOperator::LT; break;
case BinaryOperator::LE: Op = BinaryOperator::GE; break;
case BinaryOperator::GE: Op = BinaryOperator::LE; break;
default: break;
}
continue;
}
case nonloc::SymbolValKind:
if (isa<nonloc::ConcreteInt>(R)) {
ValueManager &ValMgr = Eng.getValueManager();
return ValMgr.makeNonLoc(cast<nonloc::SymbolVal>(L).getSymbol(), Op,
cast<nonloc::ConcreteInt>(R).getValue(), T);
}
else
return UnknownVal();
}
}
}
