diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/AST/ExprConstant.cpp | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp index 0f8de63bba..731bddd6b8 100644 --- a/lib/AST/ExprConstant.cpp +++ b/lib/AST/ExprConstant.cpp @@ -45,6 +45,7 @@ #include "clang/Basic/TargetInfo.h" #include "llvm/ADT/SmallString.h" #include <cstring> +#include <functional> using namespace clang; using llvm::APSInt; @@ -4138,6 +4139,23 @@ static bool HasSameBase(const LValue &A, const LValue &B) { A.getLValueFrame() == B.getLValueFrame(); } +/// Perform the given integer operation, which is known to need at most BitWidth +/// bits, and check for overflow in the original type (if that type was not an +/// unsigned type). +template<typename Operation> +static APSInt CheckedIntArithmetic(EvalInfo &Info, const Expr *E, + const APSInt &LHS, const APSInt &RHS, + unsigned BitWidth, Operation Op) { + if (LHS.isUnsigned()) + return Op(LHS, RHS); + + APSInt Value(Op(LHS.extend(BitWidth), RHS.extend(BitWidth)), false); + APSInt Result = Value.trunc(LHS.getBitWidth()); + if (Result.extend(BitWidth) != Value) + HandleOverflow(Info, E, Value, E->getType()); + return Result; +} + bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { if (E->isAssignmentOp()) return Error(E); @@ -4476,9 +4494,18 @@ bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { switch (E->getOpcode()) { default: return Error(E); - case BO_Mul: return Success(LHS * RHS, E); - case BO_Add: return Success(LHS + RHS, E); - case BO_Sub: return Success(LHS - RHS, E); + case BO_Mul: + return Success(CheckedIntArithmetic(Info, E, LHS, RHS, + LHS.getBitWidth() * 2, + std::multiplies<APSInt>()), E); + case BO_Add: + return Success(CheckedIntArithmetic(Info, E, LHS, RHS, + LHS.getBitWidth() + 1, + std::plus<APSInt>()), E); + case BO_Sub: + return Success(CheckedIntArithmetic(Info, E, LHS, RHS, + LHS.getBitWidth() + 1, + std::minus<APSInt>()), E); case BO_And: return Success(LHS & RHS, E); case BO_Xor: return Success(LHS ^ RHS, E); case BO_Or: return Success(LHS | RHS, E); @@ -5078,17 +5105,21 @@ bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { default: return Error(E); case BO_Mul: Result.multiply(RHS, APFloat::rmNearestTiesToEven); - return true; + break; case BO_Add: Result.add(RHS, APFloat::rmNearestTiesToEven); - return true; + break; case BO_Sub: Result.subtract(RHS, APFloat::rmNearestTiesToEven); - return true; + break; case BO_Div: Result.divide(RHS, APFloat::rmNearestTiesToEven); - return true; + break; } + + if (Result.isInfinity() || Result.isNaN()) + CCEDiag(E, diag::note_constexpr_float_arithmetic) << Result.isNaN(); + return true; } bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) { |