APSIntType::RangeTestResultKind
APSIntType::testInRange(const llvm::APSInt &Value,
bool AllowSignConversions) const {
// Negative numbers cannot be losslessly converted to unsigned type.
if (IsUnsigned && !AllowSignConversions &&
Value.isSigned() && Value.isNegative())
return RTR_Below;
unsigned MinBits;
if (AllowSignConversions) {
if (Value.isSigned() && !IsUnsigned)
MinBits = Value.getMinSignedBits();
else
MinBits = Value.getActiveBits();
} else {
// Signed integers can be converted to signed integers of the same width
// or (if positive) unsigned integers with one fewer bit.
// Unsigned integers can be converted to unsigned integers of the same width
// or signed integers with one more bit.
if (Value.isSigned())
MinBits = Value.getMinSignedBits() - IsUnsigned;
else
MinBits = Value.getActiveBits() + !IsUnsigned;
}
if (MinBits <= BitWidth)
return RTR_Within;
if (Value.isSigned() && Value.isNegative())
return RTR_Below;
else
return RTR_Above;
}
/// \brief Determine if two APSInts have the same value, zero- or sign-extending
/// as needed.
static bool IsSameValue(const llvm::APSInt &I1, const llvm::APSInt &I2) {
if (I1.getBitWidth() == I2.getBitWidth() && I1.isSigned() == I2.isSigned())
return I1 == I2;
// Check for a bit-width mismatch.
if (I1.getBitWidth() > I2.getBitWidth())
return IsSameValue(I1, I2.extend(I1.getBitWidth()));
else if (I2.getBitWidth() > I1.getBitWidth())
return IsSameValue(I1.extend(I2.getBitWidth()), I2);
// We have a signedness mismatch. Turn the signed value into an unsigned
// value.
if (I1.isSigned()) {
if (I1.isNegative())
return false;
return llvm::APSInt(I1, true) == I2;
}
if (I2.isNegative())
return false;
return I1 == llvm::APSInt(I2, true);
}
bool LiteralAnalyser::checkRange(QualType TLeft, const Expr* Right, clang::SourceLocation Loc, llvm::APSInt Result) {
// TODO refactor with check()
const QualType QT = TLeft.getCanonicalType();
int availableWidth = 0;
if (QT.isBuiltinType()) {
const BuiltinType* TL = cast<BuiltinType>(QT);
if (!TL->isInteger()) {
// TODO floats
return false;
}
availableWidth = TL->getIntegerWidth();
} else {
QT.dump();
assert(0 && "todo");
}
const Limit* L = getLimit(availableWidth);
assert(Result.isSigned() && "TEMP FOR NOW");
int64_t value = Result.getSExtValue();
bool overflow = false;
if (Result.isNegative()) {
const int64_t limit = L->minVal;
if (value < limit) overflow = true;
} else {
const int64_t limit = (int64_t)L->maxVal;
if (value > limit) overflow = true;
}
//fprintf(stderr, "VAL=%lld width=%d signed=%d\n", value, availableWidth, Result.isSigned());
if (overflow) {
SmallString<20> ss;
Result.toString(ss, 10, true);
StringBuilder buf1;
TLeft->DiagName(buf1);
if (Right) {
Diags.Report(Right->getLocStart(), diag::err_literal_outofbounds)
<< buf1 << L->minStr << L->maxStr << ss << Right->getSourceRange();
} else {
Diags.Report(Loc, diag::err_literal_outofbounds)
<< buf1 << L->minStr << L->maxStr << ss;
}
return false;
}
return true;
}
SVal SimpleSValBuilder::MakeSymIntVal(const SymExpr *LHS,
BinaryOperator::Opcode op,
const llvm::APSInt &RHS,
QualType resultTy) {
bool isIdempotent = false;
// Check for a few special cases with known reductions first.
switch (op) {
default:
// We can't reduce this case; just treat it normally.
break;
case BO_Mul:
// a*0 and a*1
if (RHS == 0)
return makeIntVal(0, resultTy);
else if (RHS == 1)
isIdempotent = true;
break;
case BO_Div:
// a/0 and a/1
if (RHS == 0)
// This is also handled elsewhere.
return UndefinedVal();
else if (RHS == 1)
isIdempotent = true;
break;
case BO_Rem:
// a%0 and a%1
if (RHS == 0)
// This is also handled elsewhere.
return UndefinedVal();
else if (RHS == 1)
return makeIntVal(0, resultTy);
break;
case BO_Add:
case BO_Sub:
case BO_Shl:
case BO_Shr:
case BO_Xor:
// a+0, a-0, a<<0, a>>0, a^0
if (RHS == 0)
isIdempotent = true;
break;
case BO_And:
// a&0 and a&(~0)
if (RHS == 0)
return makeIntVal(0, resultTy);
else if (RHS.isAllOnesValue())
isIdempotent = true;
break;
case BO_Or:
// a|0 and a|(~0)
if (RHS == 0)
isIdempotent = true;
else if (RHS.isAllOnesValue()) {
const llvm::APSInt &Result = BasicVals.Convert(resultTy, RHS);
return nonloc::ConcreteInt(Result);
}
break;
}
// Idempotent ops (like a*1) can still change the type of an expression.
// Wrap the LHS up in a NonLoc again and let evalCastFromNonLoc do the
// dirty work.
if (isIdempotent)
return evalCastFromNonLoc(nonloc::SymbolVal(LHS), resultTy);
// If we reach this point, the expression cannot be simplified.
// Make a SymbolVal for the entire expression, after converting the RHS.
const llvm::APSInt *ConvertedRHS = &RHS;
if (BinaryOperator::isComparisonOp(op)) {
// We're looking for a type big enough to compare the symbolic value
// with the given constant.
// FIXME: This is an approximation of Sema::UsualArithmeticConversions.
ASTContext &Ctx = getContext();
QualType SymbolType = LHS->getType();
uint64_t ValWidth = RHS.getBitWidth();
uint64_t TypeWidth = Ctx.getTypeSize(SymbolType);
if (ValWidth < TypeWidth) {
// If the value is too small, extend it.
ConvertedRHS = &BasicVals.Convert(SymbolType, RHS);
} else if (ValWidth == TypeWidth) {
// If the value is signed but the symbol is unsigned, do the comparison
// in unsigned space. [C99 6.3.1.8]
// (For the opposite case, the value is already unsigned.)
if (RHS.isSigned() && !SymbolType->isSignedIntegerOrEnumerationType())
ConvertedRHS = &BasicVals.Convert(SymbolType, RHS);
}
} else
ConvertedRHS = &BasicVals.Convert(resultTy, RHS);
return makeNonLoc(LHS, op, *ConvertedRHS, resultTy);
}