| //===--- NarrowingConversionsCheck.cpp - clang-tidy------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "NarrowingConversionsCheck.h" |
| #include "../utils/OptionsUtils.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/AST/Type.h" |
| #include "clang/ASTMatchers/ASTMatchFinder.h" |
| #include "clang/ASTMatchers/ASTMatchers.h" |
| #include "llvm/ADT/APSInt.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/SmallVector.h" |
| |
| #include <cstdint> |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace cppcoreguidelines { |
| namespace { |
| auto hasAnyListedName(const std::string &Names) { |
| const std::vector<std::string> NameList = |
| utils::options::parseStringList(Names); |
| return hasAnyName(std::vector<StringRef>(NameList.begin(), NameList.end())); |
| } |
| } // namespace |
| |
| NarrowingConversionsCheck::NarrowingConversionsCheck(StringRef Name, |
| ClangTidyContext *Context) |
| : ClangTidyCheck(Name, Context), |
| WarnOnIntegerNarrowingConversion( |
| Options.get("WarnOnIntegerNarrowingConversion", true)), |
| WarnOnFloatingPointNarrowingConversion( |
| Options.get("WarnOnFloatingPointNarrowingConversion", true)), |
| WarnWithinTemplateInstantiation( |
| Options.get("WarnWithinTemplateInstantiation", false)), |
| WarnOnEquivalentBitWidth(Options.get("WarnOnEquivalentBitWidth", true)), |
| IgnoreConversionFromTypes(Options.get("IgnoreConversionFromTypes", "")), |
| PedanticMode(Options.get("PedanticMode", false)) {} |
| |
| void NarrowingConversionsCheck::storeOptions( |
| ClangTidyOptions::OptionMap &Opts) { |
| Options.store(Opts, "WarnOnIntegerNarrowingConversion", |
| WarnOnIntegerNarrowingConversion); |
| Options.store(Opts, "WarnOnFloatingPointNarrowingConversion", |
| WarnOnFloatingPointNarrowingConversion); |
| Options.store(Opts, "WarnWithinTemplateInstantiation", |
| WarnWithinTemplateInstantiation); |
| Options.store(Opts, "WarnOnEquivalentBitWidth", WarnOnEquivalentBitWidth); |
| Options.store(Opts, "IgnoreConversionFromTypes", IgnoreConversionFromTypes); |
| Options.store(Opts, "PedanticMode", PedanticMode); |
| } |
| |
| AST_MATCHER(FieldDecl, hasIntBitwidth) { |
| assert(Node.isBitField()); |
| const ASTContext &Ctx = Node.getASTContext(); |
| unsigned IntBitWidth = Ctx.getIntWidth(Ctx.IntTy); |
| unsigned CurrentBitWidth = Node.getBitWidthValue(Ctx); |
| return IntBitWidth == CurrentBitWidth; |
| } |
| |
| void NarrowingConversionsCheck::registerMatchers(MatchFinder *Finder) { |
| // ceil() and floor() are guaranteed to return integers, even though the type |
| // is not integral. |
| const auto IsCeilFloorCallExpr = expr(callExpr(callee(functionDecl( |
| hasAnyName("::ceil", "::std::ceil", "::floor", "::std::floor"))))); |
| |
| // We may want to exclude other types from the checks, such as `size_type` |
| // and `difference_type`. These are often used to count elements, represented |
| // in 64 bits and assigned to `int`. Rarely are people counting >2B elements. |
| const auto IsConversionFromIgnoredType = |
| hasType(namedDecl(hasAnyListedName(IgnoreConversionFromTypes))); |
| |
| // `IsConversionFromIgnoredType` will ignore narrowing calls from those types, |
| // but not expressions that are promoted to an ignored type as a result of a |
| // binary expression with one of those types. |
| // For example, it will continue to reject: |
| // `int narrowed = int_value + container.size()`. |
| // We attempt to address common incidents of compound expressions with |
| // `IsIgnoredTypeTwoLevelsDeep`, allowing binary expressions that have one |
| // operand of the ignored types and the other operand of another integer type. |
| const auto IsIgnoredTypeTwoLevelsDeep = |
| anyOf(IsConversionFromIgnoredType, |
| binaryOperator(hasOperands(IsConversionFromIgnoredType, |
| hasType(isInteger())))); |
| |
| // Bitfields are special. Due to integral promotion [conv.prom/5] bitfield |
| // member access expressions are frequently wrapped by an implicit cast to |
| // `int` if that type can represent all the values of the bitfield. |
| // |
| // Consider these examples: |
| // struct SmallBitfield { unsigned int id : 4; }; |
| // x.id & 1; (case-1) |
| // x.id & 1u; (case-2) |
| // x.id << 1u; (case-3) |
| // (unsigned)x.id << 1; (case-4) |
| // |
| // Due to the promotion rules, we would get a warning for case-1. It's |
| // debatable how useful this is, but the user at least has a convenient way of |
| // //fixing// it by adding the `u` unsigned-suffix to the literal as |
| // demonstrated by case-2. However, this won't work for shift operators like |
| // the one in case-3. In case of a normal binary operator, both operands |
| // contribute to the result type. However, the type of the shift expression is |
| // the promoted type of the left operand. One could still suppress this |
| // superfluous warning by explicitly casting the bitfield member access as |
| // case-4 demonstrates, but why? The compiler already knew that the value from |
| // the member access should safely fit into an `int`, why do we have this |
| // warning in the first place? So, hereby we suppress this specific scenario. |
| // |
| // Note that the bitshift operation might invoke unspecified/undefined |
| // behavior, but that's another topic, this checker is about detecting |
| // conversion-related defects. |
| // |
| // Example AST for `x.id << 1`: |
| // BinaryOperator 'int' '<<' |
| // |-ImplicitCastExpr 'int' <IntegralCast> |
| // | `-ImplicitCastExpr 'unsigned int' <LValueToRValue> |
| // | `-MemberExpr 'unsigned int' lvalue bitfield .id |
| // | `-DeclRefExpr 'SmallBitfield' lvalue ParmVar 'x' 'SmallBitfield' |
| // `-IntegerLiteral 'int' 1 |
| const auto ImplicitIntWidenedBitfieldValue = implicitCastExpr( |
| hasCastKind(CK_IntegralCast), hasType(asString("int")), |
| has(castExpr(hasCastKind(CK_LValueToRValue), |
| has(ignoringParens(memberExpr(hasDeclaration( |
| fieldDecl(isBitField(), unless(hasIntBitwidth()))))))))); |
| |
| // Casts: |
| // i = 0.5; |
| // void f(int); f(0.5); |
| Finder->addMatcher( |
| traverse(TK_AsIs, implicitCastExpr( |
| hasImplicitDestinationType( |
| hasUnqualifiedDesugaredType(builtinType())), |
| hasSourceExpression(hasType( |
| hasUnqualifiedDesugaredType(builtinType()))), |
| unless(hasSourceExpression(IsCeilFloorCallExpr)), |
| unless(hasParent(castExpr())), |
| WarnWithinTemplateInstantiation |
| ? stmt() |
| : stmt(unless(isInTemplateInstantiation())), |
| IgnoreConversionFromTypes.empty() |
| ? castExpr() |
| : castExpr(unless(hasSourceExpression( |
| IsIgnoredTypeTwoLevelsDeep))), |
| unless(ImplicitIntWidenedBitfieldValue)) |
| .bind("cast")), |
| this); |
| |
| // Binary operators: |
| // i += 0.5; |
| Finder->addMatcher( |
| binaryOperator( |
| isAssignmentOperator(), |
| hasLHS(expr(hasType(hasUnqualifiedDesugaredType(builtinType())))), |
| hasRHS(expr(hasType(hasUnqualifiedDesugaredType(builtinType())))), |
| unless(hasRHS(IsCeilFloorCallExpr)), |
| WarnWithinTemplateInstantiation |
| ? binaryOperator() |
| : binaryOperator(unless(isInTemplateInstantiation())), |
| IgnoreConversionFromTypes.empty() |
| ? binaryOperator() |
| : binaryOperator(unless(hasRHS(IsIgnoredTypeTwoLevelsDeep))), |
| // The `=` case generates an implicit cast |
| // which is covered by the previous matcher. |
| unless(hasOperatorName("="))) |
| .bind("binary_op"), |
| this); |
| } |
| |
| static const BuiltinType *getBuiltinType(const Expr &E) { |
| return E.getType().getCanonicalType().getTypePtr()->getAs<BuiltinType>(); |
| } |
| |
| static QualType getUnqualifiedType(const Expr &E) { |
| return E.getType().getUnqualifiedType(); |
| } |
| |
| static APValue getConstantExprValue(const ASTContext &Ctx, const Expr &E) { |
| if (auto IntegerConstant = E.getIntegerConstantExpr(Ctx)) |
| return APValue(*IntegerConstant); |
| APValue Constant; |
| if (Ctx.getLangOpts().CPlusPlus && E.isCXX11ConstantExpr(Ctx, &Constant)) |
| return Constant; |
| return {}; |
| } |
| |
| static bool getIntegerConstantExprValue(const ASTContext &Context, |
| const Expr &E, llvm::APSInt &Value) { |
| APValue Constant = getConstantExprValue(Context, E); |
| if (!Constant.isInt()) |
| return false; |
| Value = Constant.getInt(); |
| return true; |
| } |
| |
| static bool getFloatingConstantExprValue(const ASTContext &Context, |
| const Expr &E, llvm::APFloat &Value) { |
| APValue Constant = getConstantExprValue(Context, E); |
| if (!Constant.isFloat()) |
| return false; |
| Value = Constant.getFloat(); |
| return true; |
| } |
| |
| namespace { |
| |
| struct IntegerRange { |
| bool contains(const IntegerRange &From) const { |
| return llvm::APSInt::compareValues(Lower, From.Lower) <= 0 && |
| llvm::APSInt::compareValues(Upper, From.Upper) >= 0; |
| } |
| |
| bool contains(const llvm::APSInt &Value) const { |
| return llvm::APSInt::compareValues(Lower, Value) <= 0 && |
| llvm::APSInt::compareValues(Upper, Value) >= 0; |
| } |
| |
| llvm::APSInt Lower; |
| llvm::APSInt Upper; |
| }; |
| |
| } // namespace |
| |
| static IntegerRange createFromType(const ASTContext &Context, |
| const BuiltinType &T) { |
| if (T.isFloatingPoint()) { |
| unsigned PrecisionBits = llvm::APFloatBase::semanticsPrecision( |
| Context.getFloatTypeSemantics(T.desugar())); |
| // Contrary to two's complement integer, floating point values are |
| // symmetric and have the same number of positive and negative values. |
| // The range of valid integers for a floating point value is: |
| // [-2^PrecisionBits, 2^PrecisionBits] |
| |
| // Values are created with PrecisionBits plus two bits: |
| // - One to express the missing negative value of 2's complement |
| // representation. |
| // - One for the sign. |
| llvm::APSInt UpperValue(PrecisionBits + 2, /*isUnsigned*/ false); |
| UpperValue.setBit(PrecisionBits); |
| llvm::APSInt LowerValue(PrecisionBits + 2, /*isUnsigned*/ false); |
| LowerValue.setBit(PrecisionBits); |
| LowerValue.setSignBit(); |
| return {LowerValue, UpperValue}; |
| } |
| assert(T.isInteger() && "Unexpected builtin type"); |
| uint64_t TypeSize = Context.getTypeSize(&T); |
| bool IsUnsignedInteger = T.isUnsignedInteger(); |
| return {llvm::APSInt::getMinValue(TypeSize, IsUnsignedInteger), |
| llvm::APSInt::getMaxValue(TypeSize, IsUnsignedInteger)}; |
| } |
| |
| static bool isWideEnoughToHold(const ASTContext &Context, |
| const BuiltinType &FromType, |
| const BuiltinType &ToType) { |
| IntegerRange FromIntegerRange = createFromType(Context, FromType); |
| IntegerRange ToIntegerRange = createFromType(Context, ToType); |
| return ToIntegerRange.contains(FromIntegerRange); |
| } |
| |
| static bool isWideEnoughToHold(const ASTContext &Context, |
| const llvm::APSInt &IntegerConstant, |
| const BuiltinType &ToType) { |
| IntegerRange ToIntegerRange = createFromType(Context, ToType); |
| return ToIntegerRange.contains(IntegerConstant); |
| } |
| |
| // Returns true iff the floating point constant can be losslessly represented |
| // by an integer in the given destination type. eg. 2.0 can be accurately |
| // represented by an int32_t, but neither 2^33 nor 2.001 can. |
| static bool isFloatExactlyRepresentable(const ASTContext &Context, |
| const llvm::APFloat &FloatConstant, |
| const QualType &DestType) { |
| unsigned DestWidth = Context.getIntWidth(DestType); |
| bool DestSigned = DestType->isSignedIntegerOrEnumerationType(); |
| llvm::APSInt Result = llvm::APSInt(DestWidth, !DestSigned); |
| bool IsExact = false; |
| bool Overflows = FloatConstant.convertToInteger( |
| Result, llvm::APFloat::rmTowardZero, &IsExact) & |
| llvm::APFloat::opInvalidOp; |
| return !Overflows && IsExact; |
| } |
| |
| static llvm::SmallString<64> getValueAsString(const llvm::APSInt &Value, |
| uint64_t HexBits) { |
| llvm::SmallString<64> Str; |
| Value.toString(Str, 10); |
| if (HexBits > 0) { |
| Str.append(" (0x"); |
| llvm::SmallString<32> HexValue; |
| Value.toStringUnsigned(HexValue, 16); |
| for (size_t I = HexValue.size(); I < (HexBits / 4); ++I) |
| Str.append("0"); |
| Str.append(HexValue); |
| Str.append(")"); |
| } |
| return Str; |
| } |
| |
| bool NarrowingConversionsCheck::isWarningInhibitedByEquivalentSize( |
| const ASTContext &Context, const BuiltinType &FromType, |
| const BuiltinType &ToType) const { |
| // With this option, we don't warn on conversions that have equivalent width |
| // in bits. eg. uint32 <-> int32. |
| if (!WarnOnEquivalentBitWidth) { |
| uint64_t FromTypeSize = Context.getTypeSize(&FromType); |
| uint64_t ToTypeSize = Context.getTypeSize(&ToType); |
| if (FromTypeSize == ToTypeSize) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void NarrowingConversionsCheck::diagNarrowType(SourceLocation SourceLoc, |
| const Expr &Lhs, |
| const Expr &Rhs) { |
| diag(SourceLoc, "narrowing conversion from %0 to %1") |
| << getUnqualifiedType(Rhs) << getUnqualifiedType(Lhs); |
| } |
| |
| void NarrowingConversionsCheck::diagNarrowTypeToSignedInt( |
| SourceLocation SourceLoc, const Expr &Lhs, const Expr &Rhs) { |
| diag(SourceLoc, "narrowing conversion from %0 to signed type %1 is " |
| "implementation-defined") |
| << getUnqualifiedType(Rhs) << getUnqualifiedType(Lhs); |
| } |
| |
| void NarrowingConversionsCheck::diagNarrowIntegerConstant( |
| SourceLocation SourceLoc, const Expr &Lhs, const Expr &Rhs, |
| const llvm::APSInt &Value) { |
| diag(SourceLoc, |
| "narrowing conversion from constant value %0 of type %1 to %2") |
| << getValueAsString(Value, /*NoHex*/ 0) << getUnqualifiedType(Rhs) |
| << getUnqualifiedType(Lhs); |
| } |
| |
| void NarrowingConversionsCheck::diagNarrowIntegerConstantToSignedInt( |
| SourceLocation SourceLoc, const Expr &Lhs, const Expr &Rhs, |
| const llvm::APSInt &Value, const uint64_t HexBits) { |
| diag(SourceLoc, "narrowing conversion from constant value %0 of type %1 " |
| "to signed type %2 is implementation-defined") |
| << getValueAsString(Value, HexBits) << getUnqualifiedType(Rhs) |
| << getUnqualifiedType(Lhs); |
| } |
| |
| void NarrowingConversionsCheck::diagNarrowConstant(SourceLocation SourceLoc, |
| const Expr &Lhs, |
| const Expr &Rhs) { |
| diag(SourceLoc, "narrowing conversion from constant %0 to %1") |
| << getUnqualifiedType(Rhs) << getUnqualifiedType(Lhs); |
| } |
| |
| void NarrowingConversionsCheck::diagConstantCast(SourceLocation SourceLoc, |
| const Expr &Lhs, |
| const Expr &Rhs) { |
| diag(SourceLoc, "constant value should be of type of type %0 instead of %1") |
| << getUnqualifiedType(Lhs) << getUnqualifiedType(Rhs); |
| } |
| |
| void NarrowingConversionsCheck::diagNarrowTypeOrConstant( |
| const ASTContext &Context, SourceLocation SourceLoc, const Expr &Lhs, |
| const Expr &Rhs) { |
| APValue Constant = getConstantExprValue(Context, Rhs); |
| if (Constant.isInt()) |
| return diagNarrowIntegerConstant(SourceLoc, Lhs, Rhs, Constant.getInt()); |
| if (Constant.isFloat()) |
| return diagNarrowConstant(SourceLoc, Lhs, Rhs); |
| return diagNarrowType(SourceLoc, Lhs, Rhs); |
| } |
| |
| void NarrowingConversionsCheck::handleIntegralCast(const ASTContext &Context, |
| SourceLocation SourceLoc, |
| const Expr &Lhs, |
| const Expr &Rhs) { |
| if (WarnOnIntegerNarrowingConversion) { |
| const BuiltinType *ToType = getBuiltinType(Lhs); |
| // From [conv.integral]p7.3.8: |
| // Conversions to unsigned integer is well defined so no warning is issued. |
| // "The resulting value is the smallest unsigned value equal to the source |
| // value modulo 2^n where n is the number of bits used to represent the |
| // destination type." |
| if (ToType->isUnsignedInteger()) |
| return; |
| const BuiltinType *FromType = getBuiltinType(Rhs); |
| |
| // With this option, we don't warn on conversions that have equivalent width |
| // in bits. eg. uint32 <-> int32. |
| if (!WarnOnEquivalentBitWidth) { |
| uint64_t FromTypeSize = Context.getTypeSize(FromType); |
| uint64_t ToTypeSize = Context.getTypeSize(ToType); |
| if (FromTypeSize == ToTypeSize) |
| return; |
| } |
| |
| llvm::APSInt IntegerConstant; |
| if (getIntegerConstantExprValue(Context, Rhs, IntegerConstant)) { |
| if (!isWideEnoughToHold(Context, IntegerConstant, *ToType)) |
| diagNarrowIntegerConstantToSignedInt(SourceLoc, Lhs, Rhs, |
| IntegerConstant, |
| Context.getTypeSize(FromType)); |
| return; |
| } |
| if (!isWideEnoughToHold(Context, *FromType, *ToType)) |
| diagNarrowTypeToSignedInt(SourceLoc, Lhs, Rhs); |
| } |
| } |
| |
| void NarrowingConversionsCheck::handleIntegralToBoolean( |
| const ASTContext &Context, SourceLocation SourceLoc, const Expr &Lhs, |
| const Expr &Rhs) { |
| // Conversion from Integral to Bool value is well defined. |
| |
| // We keep this function (even if it is empty) to make sure that |
| // handleImplicitCast and handleBinaryOperator are symmetric in their behavior |
| // and handle the same cases. |
| } |
| |
| void NarrowingConversionsCheck::handleIntegralToFloating( |
| const ASTContext &Context, SourceLocation SourceLoc, const Expr &Lhs, |
| const Expr &Rhs) { |
| const BuiltinType *ToType = getBuiltinType(Lhs); |
| llvm::APSInt IntegerConstant; |
| if (getIntegerConstantExprValue(Context, Rhs, IntegerConstant)) { |
| if (!isWideEnoughToHold(Context, IntegerConstant, *ToType)) |
| diagNarrowIntegerConstant(SourceLoc, Lhs, Rhs, IntegerConstant); |
| return; |
| } |
| |
| const BuiltinType *FromType = getBuiltinType(Rhs); |
| if (isWarningInhibitedByEquivalentSize(Context, *FromType, *ToType)) |
| return; |
| if (!isWideEnoughToHold(Context, *FromType, *ToType)) |
| diagNarrowType(SourceLoc, Lhs, Rhs); |
| } |
| |
| void NarrowingConversionsCheck::handleFloatingToIntegral( |
| const ASTContext &Context, SourceLocation SourceLoc, const Expr &Lhs, |
| const Expr &Rhs) { |
| llvm::APFloat FloatConstant(0.0); |
| if (getFloatingConstantExprValue(Context, Rhs, FloatConstant)) { |
| if (!isFloatExactlyRepresentable(Context, FloatConstant, Lhs.getType())) |
| return diagNarrowConstant(SourceLoc, Lhs, Rhs); |
| |
| if (PedanticMode) |
| return diagConstantCast(SourceLoc, Lhs, Rhs); |
| |
| return; |
| } |
| |
| const BuiltinType *FromType = getBuiltinType(Rhs); |
| const BuiltinType *ToType = getBuiltinType(Lhs); |
| if (isWarningInhibitedByEquivalentSize(Context, *FromType, *ToType)) |
| return; |
| diagNarrowType(SourceLoc, Lhs, Rhs); // Assumed always lossy. |
| } |
| |
| void NarrowingConversionsCheck::handleFloatingToBoolean( |
| const ASTContext &Context, SourceLocation SourceLoc, const Expr &Lhs, |
| const Expr &Rhs) { |
| return diagNarrowTypeOrConstant(Context, SourceLoc, Lhs, Rhs); |
| } |
| |
| void NarrowingConversionsCheck::handleBooleanToSignedIntegral( |
| const ASTContext &Context, SourceLocation SourceLoc, const Expr &Lhs, |
| const Expr &Rhs) { |
| // Conversion from Bool to SignedIntegral value is well defined. |
| |
| // We keep this function (even if it is empty) to make sure that |
| // handleImplicitCast and handleBinaryOperator are symmetric in their behavior |
| // and handle the same cases. |
| } |
| |
| void NarrowingConversionsCheck::handleFloatingCast(const ASTContext &Context, |
| SourceLocation SourceLoc, |
| const Expr &Lhs, |
| const Expr &Rhs) { |
| if (WarnOnFloatingPointNarrowingConversion) { |
| const BuiltinType *ToType = getBuiltinType(Lhs); |
| APValue Constant = getConstantExprValue(Context, Rhs); |
| if (Constant.isFloat()) { |
| // From [dcl.init.list]p7.2: |
| // Floating point constant narrowing only takes place when the value is |
| // not within destination range. We convert the value to the destination |
| // type and check if the resulting value is infinity. |
| llvm::APFloat Tmp = Constant.getFloat(); |
| bool UnusedLosesInfo; |
| Tmp.convert(Context.getFloatTypeSemantics(ToType->desugar()), |
| llvm::APFloatBase::rmNearestTiesToEven, &UnusedLosesInfo); |
| if (Tmp.isInfinity()) |
| diagNarrowConstant(SourceLoc, Lhs, Rhs); |
| return; |
| } |
| const BuiltinType *FromType = getBuiltinType(Rhs); |
| if (ToType->getKind() < FromType->getKind()) |
| diagNarrowType(SourceLoc, Lhs, Rhs); |
| } |
| } |
| |
| void NarrowingConversionsCheck::handleBinaryOperator(const ASTContext &Context, |
| SourceLocation SourceLoc, |
| const Expr &Lhs, |
| const Expr &Rhs) { |
| assert(!Lhs.isInstantiationDependent() && !Rhs.isInstantiationDependent() && |
| "Dependent types must be check before calling this function"); |
| const BuiltinType *LhsType = getBuiltinType(Lhs); |
| const BuiltinType *RhsType = getBuiltinType(Rhs); |
| if (RhsType == nullptr || LhsType == nullptr) |
| return; |
| if (RhsType->getKind() == BuiltinType::Bool && LhsType->isSignedInteger()) |
| return handleBooleanToSignedIntegral(Context, SourceLoc, Lhs, Rhs); |
| if (RhsType->isInteger() && LhsType->getKind() == BuiltinType::Bool) |
| return handleIntegralToBoolean(Context, SourceLoc, Lhs, Rhs); |
| if (RhsType->isInteger() && LhsType->isFloatingPoint()) |
| return handleIntegralToFloating(Context, SourceLoc, Lhs, Rhs); |
| if (RhsType->isInteger() && LhsType->isInteger()) |
| return handleIntegralCast(Context, SourceLoc, Lhs, Rhs); |
| if (RhsType->isFloatingPoint() && LhsType->getKind() == BuiltinType::Bool) |
| return handleFloatingToBoolean(Context, SourceLoc, Lhs, Rhs); |
| if (RhsType->isFloatingPoint() && LhsType->isInteger()) |
| return handleFloatingToIntegral(Context, SourceLoc, Lhs, Rhs); |
| if (RhsType->isFloatingPoint() && LhsType->isFloatingPoint()) |
| return handleFloatingCast(Context, SourceLoc, Lhs, Rhs); |
| } |
| |
| bool NarrowingConversionsCheck::handleConditionalOperator( |
| const ASTContext &Context, const Expr &Lhs, const Expr &Rhs) { |
| if (const auto *CO = llvm::dyn_cast<ConditionalOperator>(&Rhs)) { |
| // We have an expression like so: `output = cond ? lhs : rhs` |
| // From the point of view of narrowing conversion we treat it as two |
| // expressions `output = lhs` and `output = rhs`. |
| handleBinaryOperator(Context, CO->getLHS()->getExprLoc(), Lhs, |
| *CO->getLHS()); |
| handleBinaryOperator(Context, CO->getRHS()->getExprLoc(), Lhs, |
| *CO->getRHS()); |
| return true; |
| } |
| return false; |
| } |
| |
| void NarrowingConversionsCheck::handleImplicitCast( |
| const ASTContext &Context, const ImplicitCastExpr &Cast) { |
| if (Cast.getExprLoc().isMacroID()) |
| return; |
| const Expr &Lhs = Cast; |
| const Expr &Rhs = *Cast.getSubExpr(); |
| if (Lhs.isInstantiationDependent() || Rhs.isInstantiationDependent()) |
| return; |
| if (handleConditionalOperator(Context, Lhs, Rhs)) |
| return; |
| SourceLocation SourceLoc = Lhs.getExprLoc(); |
| switch (Cast.getCastKind()) { |
| case CK_BooleanToSignedIntegral: |
| return handleBooleanToSignedIntegral(Context, SourceLoc, Lhs, Rhs); |
| case CK_IntegralToBoolean: |
| return handleIntegralToBoolean(Context, SourceLoc, Lhs, Rhs); |
| case CK_IntegralToFloating: |
| return handleIntegralToFloating(Context, SourceLoc, Lhs, Rhs); |
| case CK_IntegralCast: |
| return handleIntegralCast(Context, SourceLoc, Lhs, Rhs); |
| case CK_FloatingToBoolean: |
| return handleFloatingToBoolean(Context, SourceLoc, Lhs, Rhs); |
| case CK_FloatingToIntegral: |
| return handleFloatingToIntegral(Context, SourceLoc, Lhs, Rhs); |
| case CK_FloatingCast: |
| return handleFloatingCast(Context, SourceLoc, Lhs, Rhs); |
| default: |
| break; |
| } |
| } |
| |
| void NarrowingConversionsCheck::handleBinaryOperator(const ASTContext &Context, |
| const BinaryOperator &Op) { |
| if (Op.getBeginLoc().isMacroID()) |
| return; |
| const Expr &Lhs = *Op.getLHS(); |
| const Expr &Rhs = *Op.getRHS(); |
| if (Lhs.isInstantiationDependent() || Rhs.isInstantiationDependent()) |
| return; |
| if (handleConditionalOperator(Context, Lhs, Rhs)) |
| return; |
| handleBinaryOperator(Context, Rhs.getBeginLoc(), Lhs, Rhs); |
| } |
| |
| void NarrowingConversionsCheck::check(const MatchFinder::MatchResult &Result) { |
| if (const auto *Op = Result.Nodes.getNodeAs<BinaryOperator>("binary_op")) |
| return handleBinaryOperator(*Result.Context, *Op); |
| if (const auto *Cast = Result.Nodes.getNodeAs<ImplicitCastExpr>("cast")) |
| return handleImplicitCast(*Result.Context, *Cast); |
| llvm_unreachable("must be binary operator or cast expression"); |
| } |
| } // namespace cppcoreguidelines |
| } // namespace tidy |
| } // namespace clang |
