virtual SVal EvalComplement(NonLoc val);
virtual SVal EvalBinOpNN(const GRState *state, BinaryOperator::Opcode op,
NonLoc lhs, NonLoc rhs, QualType resultTy);
- virtual SVal EvalBinOpLL(BinaryOperator::Opcode op, Loc lhs, Loc rhs,
- QualType resultTy);
+ virtual SVal EvalBinOpLL(const GRState *state, BinaryOperator::Opcode op,
+ Loc lhs, Loc rhs, QualType resultTy);
virtual SVal EvalBinOpLN(const GRState *state, BinaryOperator::Opcode op,
Loc lhs, NonLoc rhs, QualType resultTy);
}
}
-// Equality operators for Locs.
-// FIXME: All this logic will be revamped when we have MemRegion::getLocation()
-// implemented.
-
-static SVal EvalEquality(ValueManager &ValMgr, Loc lhs, Loc rhs, bool isEqual,
- QualType resultTy) {
-
- switch (lhs.getSubKind()) {
- default:
- assert(false && "EQ/NE not implemented for this Loc.");
- return UnknownVal();
-
- case loc::ConcreteIntKind: {
- if (SymbolRef rSym = rhs.getAsSymbol())
- return ValMgr.makeNonLoc(rSym,
- isEqual ? BinaryOperator::EQ
- : BinaryOperator::NE,
- cast<loc::ConcreteInt>(lhs).getValue(),
- resultTy);
- break;
- }
- case loc::MemRegionKind: {
- if (SymbolRef lSym = lhs.getAsLocSymbol()) {
- if (isa<loc::ConcreteInt>(rhs)) {
- return ValMgr.makeNonLoc(lSym,
- isEqual ? BinaryOperator::EQ
- : BinaryOperator::NE,
- cast<loc::ConcreteInt>(rhs).getValue(),
- resultTy);
- }
- }
- break;
- }
-
- case loc::GotoLabelKind:
- break;
+static BinaryOperator::Opcode ReverseComparison(BinaryOperator::Opcode op) {
+ switch (op) {
+ default:
+ assert(false && "Invalid opcode.");
+ case BinaryOperator::LT: return BinaryOperator::GT;
+ case BinaryOperator::GT: return BinaryOperator::LT;
+ case BinaryOperator::LE: return BinaryOperator::GE;
+ case BinaryOperator::GE: return BinaryOperator::LE;
+ case BinaryOperator::EQ:
+ case BinaryOperator::NE:
+ return op;
}
-
- return ValMgr.makeTruthVal(isEqual ? lhs == rhs : lhs != rhs, resultTy);
}
SVal SimpleSValuator::MakeSymIntVal(const SymExpr *LHS,
Loc lhsL = cast<nonloc::LocAsInteger>(lhs).getLoc();
switch (rhs.getSubKind()) {
case nonloc::LocAsIntegerKind:
- return EvalBinOpLL(op, lhsL, cast<nonloc::LocAsInteger>(rhs).getLoc(),
+ return EvalBinOpLL(state, op, lhsL,
+ cast<nonloc::LocAsInteger>(rhs).getLoc(),
resultTy);
case nonloc::ConcreteIntKind: {
// Transform the integer into a location and compare.
llvm::APSInt i = cast<nonloc::ConcreteInt>(rhs).getValue();
i.setIsUnsigned(true);
i.extOrTrunc(Ctx.getTypeSize(Ctx.VoidPtrTy));
- return EvalBinOpLL(op, lhsL, ValMgr.makeLoc(i), resultTy);
+ return EvalBinOpLL(state, op, lhsL, ValMgr.makeLoc(i), resultTy);
}
default:
switch (op) {
lhs = tmp;
switch (op) {
- case BinaryOperator::LT: op = BinaryOperator::GT; continue;
- case BinaryOperator::GT: op = BinaryOperator::LT; continue;
- case BinaryOperator::LE: op = BinaryOperator::GE; continue;
- case BinaryOperator::GE: op = BinaryOperator::LE; continue;
+ case BinaryOperator::LT:
+ case BinaryOperator::GT:
+ case BinaryOperator::LE:
+ case BinaryOperator::GE:
+ op = ReverseComparison(op);
+ continue;
case BinaryOperator::EQ:
case BinaryOperator::NE:
case BinaryOperator::Add:
}
}
-SVal SimpleSValuator::EvalBinOpLL(BinaryOperator::Opcode op, Loc lhs, Loc rhs,
+// FIXME: all this logic will change if/when we have MemRegion::getLocation().
+SVal SimpleSValuator::EvalBinOpLL(const GRState *state,
+ BinaryOperator::Opcode op,
+ Loc lhs, Loc rhs,
QualType resultTy) {
- switch (op) {
+ // Only comparisons and subtractions are valid operations on two pointers.
+ // See [C99 6.5.5 through 6.5.14] or [C++0x 5.6 through 5.15].
+ assert(BinaryOperator::isComparisonOp(op) || op == BinaryOperator::Sub);
+
+ // Special cases for when both sides are identical.
+ if (lhs == rhs) {
+ switch (op) {
default:
+ assert(false && "Unimplemented operation for two identical values");
return UnknownVal();
+ case BinaryOperator::Sub:
+ return ValMgr.makeZeroVal(resultTy);
case BinaryOperator::EQ:
+ case BinaryOperator::LE:
+ case BinaryOperator::GE:
+ return ValMgr.makeTruthVal(true, resultTy);
case BinaryOperator::NE:
- return EvalEquality(ValMgr, lhs, rhs, op == BinaryOperator::EQ, resultTy);
case BinaryOperator::LT:
case BinaryOperator::GT:
- // FIXME: Generalize. For now, just handle the trivial case where
- // the two locations are identical.
- if (lhs == rhs)
+ return ValMgr.makeTruthVal(false, resultTy);
+ }
+ }
+
+ switch (lhs.getSubKind()) {
+ default:
+ assert(false && "Ordering not implemented for this Loc.");
+ return UnknownVal();
+
+ case loc::GotoLabelKind:
+ // The only thing we know about labels is that they're non-null.
+ if (rhs.isZeroConstant()) {
+ switch (op) {
+ default:
+ break;
+ case BinaryOperator::Sub:
+ return EvalCastL(lhs, resultTy);
+ case BinaryOperator::EQ:
+ case BinaryOperator::LE:
+ case BinaryOperator::LT:
+ return ValMgr.makeTruthVal(false, resultTy);
+ case BinaryOperator::NE:
+ case BinaryOperator::GT:
+ case BinaryOperator::GE:
+ return ValMgr.makeTruthVal(true, resultTy);
+ }
+ }
+ // There may be two labels for the same location, and a function region may
+ // have the same address as a label at the start of the function (depending
+ // on the ABI).
+ // FIXME: we can probably do a comparison against other MemRegions, though.
+ // FIXME: is there a way to tell if two labels refer to the same location?
+ return UnknownVal();
+
+ case loc::ConcreteIntKind: {
+ // If one of the operands is a symbol and the other is a constant,
+ // build an expression for use by the constraint manager.
+ if (SymbolRef rSym = rhs.getAsLocSymbol()) {
+ // We can only build expressions with symbols on the left,
+ // so we need a reversible operator.
+ if (!BinaryOperator::isComparisonOp(op))
+ return UnknownVal();
+
+ const llvm::APSInt &lVal = cast<loc::ConcreteInt>(lhs).getValue();
+ return ValMgr.makeNonLoc(rSym, ReverseComparison(op), lVal, resultTy);
+ }
+
+ // If both operands are constants, just perform the operation.
+ if (loc::ConcreteInt *rInt = dyn_cast<loc::ConcreteInt>(&rhs)) {
+ BasicValueFactory &BVF = ValMgr.getBasicValueFactory();
+ SVal ResultVal = cast<loc::ConcreteInt>(lhs).EvalBinOp(BVF, op, *rInt);
+ if (Loc *Result = dyn_cast<Loc>(&ResultVal))
+ return EvalCastL(*Result, resultTy);
+ else
+ return UnknownVal();
+ }
+
+ // Special case comparisons against NULL.
+ // This must come after the test if the RHS is a symbol, which is used to
+ // build constraints. The address of any non-symbolic region is guaranteed
+ // to be non-NULL, as is any label.
+ assert(isa<loc::MemRegionVal>(rhs) || isa<loc::GotoLabel>(rhs));
+ if (lhs.isZeroConstant()) {
+ switch (op) {
+ default:
+ break;
+ case BinaryOperator::EQ:
+ case BinaryOperator::GT:
+ case BinaryOperator::GE:
+ return ValMgr.makeTruthVal(false, resultTy);
+ case BinaryOperator::NE:
+ case BinaryOperator::LT:
+ case BinaryOperator::LE:
+ return ValMgr.makeTruthVal(true, resultTy);
+ }
+ }
+
+ // Comparing an arbitrary integer to a region or label address is
+ // completely unknowable.
+ return UnknownVal();
+ }
+ case loc::MemRegionKind: {
+ if (loc::ConcreteInt *rInt = dyn_cast<loc::ConcreteInt>(&rhs)) {
+ // If one of the operands is a symbol and the other is a constant,
+ // build an expression for use by the constraint manager.
+ if (SymbolRef lSym = lhs.getAsLocSymbol())
+ return MakeSymIntVal(lSym, op, rInt->getValue(), resultTy);
+
+ // Special case comparisons to NULL.
+ // This must come after the test if the LHS is a symbol, which is used to
+ // build constraints. The address of any non-symbolic region is guaranteed
+ // to be non-NULL.
+ if (rInt->isZeroConstant()) {
+ switch (op) {
+ default:
+ break;
+ case BinaryOperator::Sub:
+ return EvalCastL(lhs, resultTy);
+ case BinaryOperator::EQ:
+ case BinaryOperator::LT:
+ case BinaryOperator::LE:
+ return ValMgr.makeTruthVal(false, resultTy);
+ case BinaryOperator::NE:
+ case BinaryOperator::GT:
+ case BinaryOperator::GE:
+ return ValMgr.makeTruthVal(true, resultTy);
+ }
+ }
+
+ // Comparing a region to an arbitrary integer is completely unknowable.
+ return UnknownVal();
+ }
+
+ // Get both values as regions, if possible.
+ const MemRegion *LeftMR = lhs.getAsRegion();
+ assert(LeftMR && "MemRegionKind SVal doesn't have a region!");
+
+ const MemRegion *RightMR = rhs.getAsRegion();
+ if (!RightMR)
+ // The RHS is probably a label, which in theory could address a region.
+ // FIXME: we can probably make a more useful statement about non-code
+ // regions, though.
+ return UnknownVal();
+
+ // If both values wrap regions, see if they're from different base regions.
+ const MemRegion *LeftBase = LeftMR->getBaseRegion();
+ const MemRegion *RightBase = RightMR->getBaseRegion();
+ if (LeftBase != RightBase &&
+ !isa<SymbolicRegion>(LeftBase) && !isa<SymbolicRegion>(RightBase)) {
+ switch (op) {
+ default:
+ return UnknownVal();
+ case BinaryOperator::EQ:
return ValMgr.makeTruthVal(false, resultTy);
+ case BinaryOperator::NE:
+ return ValMgr.makeTruthVal(true, resultTy);
+ }
+ }
+
+ // The two regions are from the same base region. See if they're both a
+ // type of region we know how to compare.
+
+ // FIXME: If/when there is a getAsRawOffset() for FieldRegions, this
+ // ElementRegion path and the FieldRegion path below should be unified.
+ if (const ElementRegion *LeftER = dyn_cast<ElementRegion>(LeftMR)) {
+ // First see if the right region is also an ElementRegion.
+ const ElementRegion *RightER = dyn_cast<ElementRegion>(RightMR);
+ if (!RightER)
+ return UnknownVal();
+
+ // Next, see if the two ERs have the same super-region and matching types.
+ // FIXME: This should do something useful even if the types don't match,
+ // though if both indexes are constant the RegionRawOffset path will
+ // give the correct answer.
+ if (LeftER->getSuperRegion() == RightER->getSuperRegion() &&
+ LeftER->getElementType() == RightER->getElementType()) {
+ // Get the left index and cast it to the correct type.
+ // If the index is unknown or undefined, bail out here.
+ SVal LeftIndexVal = LeftER->getIndex();
+ NonLoc *LeftIndex = dyn_cast<NonLoc>(&LeftIndexVal);
+ if (!LeftIndex)
+ return UnknownVal();
+ LeftIndexVal = EvalCastNL(*LeftIndex, resultTy);
+ LeftIndex = dyn_cast<NonLoc>(&LeftIndexVal);
+ if (!LeftIndex)
+ return UnknownVal();
+
+ // Do the same for the right index.
+ SVal RightIndexVal = RightER->getIndex();
+ NonLoc *RightIndex = dyn_cast<NonLoc>(&RightIndexVal);
+ if (!RightIndex)
+ return UnknownVal();
+ RightIndexVal = EvalCastNL(*RightIndex, resultTy);
+ RightIndex = dyn_cast<NonLoc>(&RightIndexVal);
+ if (!RightIndex)
+ return UnknownVal();
+
+ // Actually perform the operation.
+ // EvalBinOpNN expects the two indexes to already be the right type.
+ return EvalBinOpNN(state, op, *LeftIndex, *RightIndex, resultTy);
+ }
+
+ // If the element indexes aren't comparable, see if the raw offsets are.
+ RegionRawOffset LeftOffset = LeftER->getAsRawOffset();
+ RegionRawOffset RightOffset = RightER->getAsRawOffset();
+
+ if (LeftOffset.getRegion() != NULL &&
+ LeftOffset.getRegion() == RightOffset.getRegion()) {
+ int64_t left = LeftOffset.getByteOffset();
+ int64_t right = RightOffset.getByteOffset();
+
+ switch (op) {
+ default:
+ return UnknownVal();
+ case BinaryOperator::LT:
+ return ValMgr.makeTruthVal(left < right, resultTy);
+ case BinaryOperator::GT:
+ return ValMgr.makeTruthVal(left > right, resultTy);
+ case BinaryOperator::LE:
+ return ValMgr.makeTruthVal(left <= right, resultTy);
+ case BinaryOperator::GE:
+ return ValMgr.makeTruthVal(left >= right, resultTy);
+ case BinaryOperator::EQ:
+ return ValMgr.makeTruthVal(left == right, resultTy);
+ case BinaryOperator::NE:
+ return ValMgr.makeTruthVal(left != right, resultTy);
+ }
+ }
+
+ // If we get here, we have no way of comparing the ElementRegions.
return UnknownVal();
+ }
+
+ // See if both regions are fields of the same structure.
+ // FIXME: This doesn't handle nesting, inheritance, or Objective-C ivars.
+ if (const FieldRegion *LeftFR = dyn_cast<FieldRegion>(LeftMR)) {
+ // Only comparisons are meaningful here!
+ if (!BinaryOperator::isComparisonOp(op))
+ return UnknownVal();
+
+ // First see if the right region is also a FieldRegion.
+ const FieldRegion *RightFR = dyn_cast<FieldRegion>(RightMR);
+ if (!RightFR)
+ return UnknownVal();
+
+ // Next, see if the two FRs have the same super-region.
+ // FIXME: This doesn't handle casts yet, and simply stripping the casts
+ // doesn't help.
+ if (LeftFR->getSuperRegion() != RightFR->getSuperRegion())
+ return UnknownVal();
+
+ const FieldDecl *LeftFD = LeftFR->getDecl();
+ const FieldDecl *RightFD = RightFR->getDecl();
+ const RecordDecl *RD = LeftFD->getParent();
+
+ // Make sure the two FRs are from the same kind of record. Just in case!
+ // FIXME: This is probably where inheritance would be a problem.
+ if (RD != RightFD->getParent())
+ return UnknownVal();
+
+ // We know for sure that the two fields are not the same, since that
+ // would have given us the same SVal.
+ if (op == BinaryOperator::EQ)
+ return ValMgr.makeTruthVal(false, resultTy);
+ if (op == BinaryOperator::NE)
+ return ValMgr.makeTruthVal(true, resultTy);
+
+ // Iterate through the fields and see which one comes first.
+ // [C99 6.7.2.1.13] "Within a structure object, the non-bit-field
+ // members and the units in which bit-fields reside have addresses that
+ // increase in the order in which they are declared."
+ bool leftFirst = (op == BinaryOperator::LT || op == BinaryOperator::LE);
+ for (RecordDecl::field_iterator I = RD->field_begin(),
+ E = RD->field_end(); I!=E; ++I) {
+ if (*I == LeftFD)
+ return ValMgr.makeTruthVal(leftFirst, resultTy);
+ if (*I == RightFD)
+ return ValMgr.makeTruthVal(!leftFirst, resultTy);
+ }
+
+ assert(false && "Fields not found in parent record's definition");
+ }
+
+ // If we get here, we have no way of comparing the regions.
+ return UnknownVal();
+ }
}
}
// 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 (BinaryOperator::isComparisonOp(op)) {
if (nonloc::ConcreteInt *rhsInt = dyn_cast<nonloc::ConcreteInt>(&rhs)) {
const llvm::APSInt *x = &rhsInt->getValue();
ASTContext &ctx = ValMgr.getContext();
if (x->isSigned())
x = &ValMgr.getBasicValueFactory().getValue(*x, true);
- return EvalBinOpLL(op, lhs, loc::ConcreteInt(*x), resultTy);
+ return EvalBinOpLL(state, op, lhs, loc::ConcreteInt(*x), resultTy);
}
}
}
projects / clang / commitdiff