123 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "UseTransparentFunctorsCheck.h"10#include "clang/ASTMatchers/ASTMatchFinder.h"11 12using namespace clang::ast_matchers;13 14namespace clang::tidy::modernize {15 16UseTransparentFunctorsCheck::UseTransparentFunctorsCheck(17 StringRef Name, ClangTidyContext *Context)18 : ClangTidyCheck(Name, Context), SafeMode(Options.get("SafeMode", false)) {}19 20void UseTransparentFunctorsCheck::storeOptions(21 ClangTidyOptions::OptionMap &Opts) {22 Options.store(Opts, "SafeMode", SafeMode);23}24 25void UseTransparentFunctorsCheck::registerMatchers(MatchFinder *Finder) {26 const auto TransparentFunctors =27 classTemplateSpecializationDecl(28 unless(hasAnyTemplateArgument(refersToType(voidType()))),29 hasAnyName("::std::plus", "::std::minus", "::std::multiplies",30 "::std::divides", "::std::modulus", "::std::negate",31 "::std::equal_to", "::std::not_equal_to", "::std::greater",32 "::std::less", "::std::greater_equal", "::std::less_equal",33 "::std::logical_and", "::std::logical_or",34 "::std::logical_not", "::std::bit_and", "::std::bit_or",35 "::std::bit_xor", "::std::bit_not"))36 .bind("FunctorClass");37 38 // Non-transparent functor mentioned as a template parameter. FIXIT.39 Finder->addMatcher(40 loc(qualType(hasDeclaration(classTemplateSpecializationDecl(41 unless(hasAnyTemplateArgument(templateArgument(refersToType(42 qualType(pointsTo(qualType(isAnyCharacter()))))))),43 hasAnyTemplateArgument(44 templateArgument(refersToType(qualType(45 hasDeclaration(TransparentFunctors))))46 .bind("Functor"))))))47 .bind("FunctorParentLoc"),48 this);49 50 if (SafeMode)51 return;52 53 // Non-transparent functor constructed. No FIXIT. There is no easy way54 // to rule out the problematic char* vs string case.55 Finder->addMatcher(cxxConstructExpr(hasDeclaration(cxxMethodDecl(56 ofClass(TransparentFunctors))),57 unless(isInTemplateInstantiation()))58 .bind("FuncInst"),59 this);60}61 62static const StringRef Message = "prefer transparent functors '%0<>'";63 64template <typename T> static T getInnerTypeLocAs(TypeLoc Loc) {65 T Result;66 while (Result.isNull() && !Loc.isNull()) {67 Result = Loc.getAs<T>();68 Loc = Loc.getNextTypeLoc();69 }70 return Result;71}72 73void UseTransparentFunctorsCheck::check(74 const MatchFinder::MatchResult &Result) {75 const auto *FuncClass =76 Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>("FunctorClass");77 if (const auto *FuncInst =78 Result.Nodes.getNodeAs<CXXConstructExpr>("FuncInst")) {79 diag(FuncInst->getBeginLoc(), Message) << FuncClass->getName();80 return;81 }82 83 const auto *Functor = Result.Nodes.getNodeAs<TemplateArgument>("Functor");84 const auto FunctorParentLoc =85 Result.Nodes.getNodeAs<TypeLoc>("FunctorParentLoc")86 ->getAs<TemplateSpecializationTypeLoc>();87 88 if (!FunctorParentLoc)89 return;90 91 unsigned ArgNum = 0;92 const auto *FunctorParentType =93 FunctorParentLoc.getType()->castAs<TemplateSpecializationType>();94 for (; ArgNum < FunctorParentType->template_arguments().size(); ++ArgNum) {95 const TemplateArgument &Arg =96 FunctorParentType->template_arguments()[ArgNum];97 if (Arg.getKind() != TemplateArgument::Type)98 continue;99 const QualType ParentArgType = Arg.getAsType();100 if (ParentArgType->isRecordType() &&101 ParentArgType->getAsCXXRecordDecl() ==102 Functor->getAsType()->getAsCXXRecordDecl())103 break;104 }105 // Functor is a default template argument.106 if (ArgNum == FunctorParentType->template_arguments().size())107 return;108 const TemplateArgumentLoc FunctorLoc = FunctorParentLoc.getArgLoc(ArgNum);109 auto FunctorTypeLoc = getInnerTypeLocAs<TemplateSpecializationTypeLoc>(110 FunctorLoc.getTypeSourceInfo()->getTypeLoc());111 if (FunctorTypeLoc.isNull())112 return;113 114 const SourceLocation ReportLoc = FunctorLoc.getLocation();115 if (ReportLoc.isInvalid())116 return;117 diag(ReportLoc, Message) << FuncClass->getName()118 << FixItHint::CreateRemoval(119 FunctorTypeLoc.getArgLoc(0).getSourceRange());120}121 122} // namespace clang::tidy::modernize123