10 #include "../utils/Matchers.h" 11 #include "clang/AST/ASTContext.h" 12 #include "clang/ASTMatchers/ASTMatchFinder.h" 20 MisplacedWideningCastCheck::MisplacedWideningCastCheck(
23 CheckImplicitCasts(Options.get(
"CheckImplicitCasts", false)) {}
27 Options.
store(Opts,
"CheckImplicitCasts", CheckImplicitCasts);
32 expr(anyOf(binaryOperator(
33 anyOf(hasOperatorName(
"+"), hasOperatorName(
"-"),
34 hasOperatorName(
"*"), hasOperatorName(
"<<"))),
35 unaryOperator(hasOperatorName(
"~"))),
39 const auto ExplicitCast = explicitCastExpr(hasDestinationType(isInteger()),
40 has(ignoringParenImpCasts(Calc)));
41 const auto ImplicitCast =
42 implicitCastExpr(hasImplicitDestinationType(isInteger()),
43 has(ignoringParenImpCasts(Calc)));
44 const auto Cast = expr(anyOf(ExplicitCast, ImplicitCast)).bind(
"Cast");
46 Finder->addMatcher(varDecl(hasInitializer(Cast)),
this);
47 Finder->addMatcher(returnStmt(hasReturnValue(Cast)),
this);
48 Finder->addMatcher(callExpr(hasAnyArgument(Cast)),
this);
49 Finder->addMatcher(binaryOperator(hasOperatorName(
"="), hasRHS(Cast)),
this);
51 binaryOperator(matchers::isComparisonOperator(), hasEitherOperand(Cast)),
57 E = E->IgnoreParenImpCasts();
59 if (
const auto *Bop = dyn_cast<BinaryOperator>(E)) {
62 if (Bop->getOpcode() == BO_Mul)
63 return LHSWidth + RHSWidth;
64 if (Bop->getOpcode() == BO_Add)
65 return std::max(LHSWidth, RHSWidth) + 1;
66 if (Bop->getOpcode() == BO_Rem) {
68 if (Bop->getRHS()->EvaluateAsInt(Result, Context))
69 return Result.Val.getInt().getActiveBits();
70 }
else if (Bop->getOpcode() == BO_Shl) {
72 if (Bop->getRHS()->EvaluateAsInt(Result, Context)) {
76 return LHSWidth + Result.Val.getInt().getExtValue();
82 }
else if (
const auto *Uop = dyn_cast<UnaryOperator>(E)) {
84 if (Uop->getOpcode() == UO_Not)
87 QualType T = Uop->getType();
88 return T->isIntegerType() ? Context.getIntWidth(T) : 1024U;
89 }
else if (
const auto *I = dyn_cast<IntegerLiteral>(E)) {
90 return I->getValue().getActiveBits();
93 return Context.getIntWidth(E->getType());
98 case BuiltinType::UChar:
100 case BuiltinType::SChar:
102 case BuiltinType::Char_U:
104 case BuiltinType::Char_S:
106 case BuiltinType::UShort:
108 case BuiltinType::Short:
110 case BuiltinType::UInt:
112 case BuiltinType::Int:
114 case BuiltinType::ULong:
116 case BuiltinType::Long:
118 case BuiltinType::ULongLong:
120 case BuiltinType::LongLong:
122 case BuiltinType::UInt128:
124 case BuiltinType::Int128:
133 case BuiltinType::UChar:
135 case BuiltinType::SChar:
137 case BuiltinType::Char_U:
139 case BuiltinType::Char_S:
141 case BuiltinType::Char16:
143 case BuiltinType::Char32:
152 case BuiltinType::UChar:
154 case BuiltinType::SChar:
156 case BuiltinType::Char_U:
158 case BuiltinType::Char_S:
160 case BuiltinType::WChar_U:
162 case BuiltinType::WChar_S:
170 int FirstSize, SecondSize;
173 return FirstSize > SecondSize;
176 return FirstSize > SecondSize;
179 return FirstSize > SecondSize;
184 const auto *Cast = Result.Nodes.getNodeAs<CastExpr>(
"Cast");
185 if (!CheckImplicitCasts && isa<ImplicitCastExpr>(Cast))
187 if (Cast->getBeginLoc().isMacroID())
190 const auto *Calc = Result.Nodes.getNodeAs<Expr>(
"Calc");
191 if (Calc->getBeginLoc().isMacroID())
194 if (Cast->isTypeDependent() || Cast->isValueDependent() ||
195 Calc->isTypeDependent() || Calc->isValueDependent())
198 ASTContext &Context = *Result.Context;
200 QualType CastType = Cast->getType();
201 QualType CalcType = Calc->getType();
204 if (Context.getIntWidth(CastType) < Context.getIntWidth(CalcType))
210 if (Context.getIntWidth(CastType) == Context.getIntWidth(CalcType)) {
211 const auto *CastBuiltinType =
212 dyn_cast<BuiltinType>(CastType->getUnqualifiedDesugaredType());
213 const auto *CalcBuiltinType =
214 dyn_cast<BuiltinType>(CalcType->getUnqualifiedDesugaredType());
215 if (!CastBuiltinType || !CalcBuiltinType)
217 if (!
isFirstWider(CastBuiltinType->getKind(), CalcBuiltinType->getKind()))
226 diag(Cast->getBeginLoc(),
"either cast from %0 to %1 is ineffective, or " 227 "there is loss of precision before the conversion")
228 << CalcType << CastType;
static int relativeIntSizes(BuiltinType::Kind Kind)
static int relativeCharSizesW(BuiltinType::Kind Kind)
static unsigned getMaxCalculationWidth(const ASTContext &Context, const Expr *E)
Base class for all clang-tidy checks.
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
static int relativeCharSizes(BuiltinType::Kind Kind)
static bool isFirstWider(BuiltinType::Kind First, BuiltinType::Kind Second)
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
static constexpr llvm::StringLiteral Name
std::map< std::string, std::string > OptionMap
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check's name.