void NamespaceCommentCheck::registerMatchers(MatchFinder *Finder) {
  // Only register the matchers for C++; the functionality currently does not
  // provide any benefit to other languages, despite being benign.
  if (getLangOpts().CPlusPlus)
    Finder->addMatcher(namespaceDecl().bind("namespace"), this);
}
void ProTypeConstCastCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  Finder->addMatcher(cxxConstCastExpr().bind("cast"), this);
}
void UseOverrideCheck::registerMatchers(MatchFinder *Finder) {
  // Only register the matcher for C++11.
  if (getLangOpts().CPlusPlus11)
    Finder->addMatcher(cxxMethodDecl(isOverride()).bind("method"), this);
}
void UseOverrideCheck::check(const MatchFinder::MatchResult &Result) {
  const auto *Method = Result.Nodes.getNodeAs<FunctionDecl>("method");
  const SourceManager &Sources = *Result.SourceManager;

  assert(Method != nullptr);
  if (Method->getInstantiatedFromMemberFunction() != nullptr)
    Method = Method->getInstantiatedFromMemberFunction();

  if (Method->isImplicit() || Method->getLocation().isMacroID() ||
      Method->isOutOfLine())
    return;

  bool HasVirtual = Method->isVirtualAsWritten();
  bool HasOverride = Method->getAttr<OverrideAttr>();
  bool HasFinal = Method->getAttr<FinalAttr>();

  bool OnlyVirtualSpecified = HasVirtual && !HasOverride && !HasFinal;
  unsigned KeywordCount = HasVirtual + HasOverride + HasFinal;

  if (!OnlyVirtualSpecified && KeywordCount == 1)
    return; // Nothing to do.

  std::string Message;

  if (OnlyVirtualSpecified) {
    Message =
        "prefer using 'override' or (rarely) 'final' instead of 'virtual'";
  } else if (KeywordCount == 0) {
    Message = "annotate this function with 'override' or (rarely) 'final'";
  } else {
    StringRef Redundant =
        HasVirtual ? (HasOverride && HasFinal ? "'virtual' and 'override' are"
                                              : "'virtual' is")
                   : "'override' is";
    StringRef Correct = HasFinal ? "'final'" : "'override'";

    Message = (llvm::Twine(Redundant) +
               " redundant since the function is already declared " + Correct)
                  .str();
  }

  DiagnosticBuilder Diag = diag(Method->getLocation(), Message);

  CharSourceRange FileRange = Lexer::makeFileCharRange(
      CharSourceRange::getTokenRange(Method->getSourceRange()), Sources,
      getLangOpts());

  if (!FileRange.isValid())
    return;

  // FIXME: Instead of re-lexing and looking for specific macros such as
  // 'ABSTRACT', properly store the location of 'virtual' and '= 0' in each
  // FunctionDecl.
  SmallVector<Token, 16> Tokens = ParseTokens(FileRange, Result);

  // Add 'override' on inline declarations that don't already have it.
  if (!HasFinal && !HasOverride) {
    SourceLocation InsertLoc;
    StringRef ReplacementText = "override ";
    SourceLocation MethodLoc = Method->getLocation();

    for (Token T : Tokens) {
      if (T.is(tok::kw___attribute) &&
          !Sources.isBeforeInTranslationUnit(T.getLocation(), MethodLoc)) {
        InsertLoc = T.getLocation();
        break;
      }
    }

    if (Method->hasAttrs()) {
      for (const clang::Attr *A : Method->getAttrs()) {
        if (!A->isImplicit() && !A->isInherited()) {
          SourceLocation Loc =
              Sources.getExpansionLoc(A->getRange().getBegin());
          if ((!InsertLoc.isValid() ||
               Sources.isBeforeInTranslationUnit(Loc, InsertLoc)) &&
              !Sources.isBeforeInTranslationUnit(Loc, MethodLoc))
            InsertLoc = Loc;
        }
      }
    }

    if (InsertLoc.isInvalid() && Method->doesThisDeclarationHaveABody() &&
        Method->getBody() && !Method->isDefaulted()) {
      // For methods with inline definition, add the override keyword at the
      // end of the declaration of the function, but prefer to put it on the
      // same line as the declaration if the beginning brace for the start of
      // the body falls on the next line.
      Token LastNonCommentToken;
      for (Token T : Tokens) {
        if (!T.is(tok::comment)) {
          LastNonCommentToken = T;
        }
      }
      InsertLoc = LastNonCommentToken.getEndLoc();
      ReplacementText = " override";
    }

    if (!InsertLoc.isValid()) {
      // For declarations marked with "= 0" or "= [default|delete]", the end
      // location will point until after those markings. Therefore, the override
      // keyword shouldn't be inserted at the end, but before the '='.
      if (Tokens.size() > 2 && (GetText(Tokens.back(), Sources) == "0" ||
                                Tokens.back().is(tok::kw_default) ||
                                Tokens.back().is(tok::kw_delete)) &&
          GetText(Tokens[Tokens.size() - 2], Sources) == "=") {
        InsertLoc = Tokens[Tokens.size() - 2].getLocation();
        // Check if we need to insert a space.
        if ((Tokens[Tokens.size() - 2].getFlags() & Token::LeadingSpace) == 0)
          ReplacementText = " override ";
      } else if (GetText(Tokens.back(), Sources) == "ABSTRACT") {
        InsertLoc = Tokens.back().getLocation();
      }
    }

    if (!InsertLoc.isValid()) {
      InsertLoc = FileRange.getEnd();
      ReplacementText = " override";
    }
    Diag << FixItHint::CreateInsertion(InsertLoc, ReplacementText);
  }

  if (HasFinal && HasOverride) {
    SourceLocation OverrideLoc = Method->getAttr<OverrideAttr>()->getLocation();
    Diag << FixItHint::CreateRemoval(
        CharSourceRange::getTokenRange(OverrideLoc, OverrideLoc));
  }

  if (HasVirtual) {
    for (Token Tok : Tokens) {
      if (Tok.is(tok::kw_virtual)) {
        Diag << FixItHint::CreateRemoval(CharSourceRange::getTokenRange(
            Tok.getLocation(), Tok.getLocation()));
        break;
      }
    }
  }
}
void UnaryStaticAssertCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus17)
    return;

  Finder->addMatcher(staticAssertDecl().bind("static_assert"), this);
}
void UpgradeDurationConversionsCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus)
    return;

  // For the arithmetic calls, we match only the uses of the templated operators
  // where the template parameter is not a built-in type. This means the
  // instantiation makes use of an available user defined conversion to
  // `int64_t`.
  //
  // The implementation of these templates will be updated to fail SFINAE for
  // non-integral types. We match them to suggest an explicit cast.

  // Match expressions like `a *= b` and `a /= b` where `a` has type
  // `absl::Duration` and `b` is not of a built-in type.
  Finder->addMatcher(
      cxxOperatorCallExpr(
          argumentCountIs(2),
          hasArgument(
              0, expr(hasType(cxxRecordDecl(hasName("::absl::Duration"))))),
          hasArgument(1, expr().bind("arg")),
          callee(functionDecl(
              hasParent(functionTemplateDecl()),
              unless(hasTemplateArgument(0, refersToType(builtinType()))),
              hasAnyName("operator*=", "operator/=")))),
      this);

  // Match expressions like `a.operator*=(b)` and `a.operator/=(b)` where `a`
  // has type `absl::Duration` and `b` is not of a built-in type.
  Finder->addMatcher(
      cxxMemberCallExpr(
          callee(cxxMethodDecl(
              ofClass(cxxRecordDecl(hasName("::absl::Duration"))),
              hasParent(functionTemplateDecl()),
              unless(hasTemplateArgument(0, refersToType(builtinType()))),
              hasAnyName("operator*=", "operator/="))),
          argumentCountIs(1), hasArgument(0, expr().bind("arg"))),
      this);

  // Match expressions like `a * b`, `a / b`, `operator*(a, b)`, and
  // `operator/(a, b)` where `a` has type `absl::Duration` and `b` is not of a
  // built-in type.
  Finder->addMatcher(
      callExpr(callee(functionDecl(
                   hasParent(functionTemplateDecl()),
                   unless(hasTemplateArgument(0, refersToType(builtinType()))),
                   hasAnyName("::absl::operator*", "::absl::operator/"))),
               argumentCountIs(2),
               hasArgument(0, expr(hasType(
                                  cxxRecordDecl(hasName("::absl::Duration"))))),
               hasArgument(1, expr().bind("arg"))),
      this);

  // Match expressions like `a * b` and `operator*(a, b)` where `a` is not of a
  // built-in type and `b` has type `absl::Duration`.
  Finder->addMatcher(
      callExpr(callee(functionDecl(
                   hasParent(functionTemplateDecl()),
                   unless(hasTemplateArgument(0, refersToType(builtinType()))),
                   hasName("::absl::operator*"))),
               argumentCountIs(2), hasArgument(0, expr().bind("arg")),
               hasArgument(1, expr(hasType(cxxRecordDecl(
                                  hasName("::absl::Duration")))))),
      this);

  // For the factory functions, we match only the non-templated overloads that
  // take an `int64_t` parameter. Within these calls, we care about implicit
  // casts through a user defined conversion to `int64_t`.
  //
  // The factory functions will be updated to be templated and SFINAE on whether
  // the template parameter is an integral type. This complements the already
  // existing templated overloads that only accept floating point types.

  // Match calls like:
  //   `absl::Nanoseconds(x)`
  //   `absl::Microseconds(x)`
  //   `absl::Milliseconds(x)`
  //   `absl::Seconds(x)`
  //   `absl::Minutes(x)`
  //   `absl::Hours(x)`
  // where `x` is not of a built-in type.
  Finder->addMatcher(
      implicitCastExpr(
          anyOf(hasCastKind(CK_UserDefinedConversion),
                has(implicitCastExpr(hasCastKind(CK_UserDefinedConversion)))),
          hasParent(callExpr(
              callee(functionDecl(DurationFactoryFunction(),
                  unless(hasParent(functionTemplateDecl())))),
              hasArgument(0, expr().bind("arg"))))),
      this);
}
void ContainerSizeEmptyCheck::check(const MatchFinder::MatchResult &Result) {
  const auto *MemberCall =
      Result.Nodes.getNodeAs<CXXMemberCallExpr>("SizeCallExpr");
  const auto *BinaryOp = Result.Nodes.getNodeAs<BinaryOperator>("SizeBinaryOp");
  const auto *E = Result.Nodes.getNodeAs<Expr>("STLObject");
  FixItHint Hint;
  std::string ReplacementText =
      Lexer::getSourceText(CharSourceRange::getTokenRange(E->getSourceRange()),
                           *Result.SourceManager, getLangOpts());
  if (E->getType()->isPointerType())
    ReplacementText += "->empty()";
  else
    ReplacementText += ".empty()";

  if (BinaryOp) { // Determine the correct transformation.
    bool Negation = false;
    const bool ContainerIsLHS =
        !llvm::isa<IntegerLiteral>(BinaryOp->getLHS()->IgnoreImpCasts());
    const auto OpCode = BinaryOp->getOpcode();
    uint64_t Value = 0;
    if (ContainerIsLHS) {
      if (const auto *Literal = llvm::dyn_cast<IntegerLiteral>(
              BinaryOp->getRHS()->IgnoreImpCasts()))
        Value = Literal->getValue().getLimitedValue();
      else
        return;
    } else {
      Value =
          llvm::dyn_cast<IntegerLiteral>(BinaryOp->getLHS()->IgnoreImpCasts())
              ->getValue()
              .getLimitedValue();
    }

    // Constant that is not handled.
    if (Value > 1)
      return;

    if (Value == 1 && (OpCode == BinaryOperatorKind::BO_EQ ||
                       OpCode == BinaryOperatorKind::BO_NE))
      return;

    // Always true, no warnings for that.
    if ((OpCode == BinaryOperatorKind::BO_GE && Value == 0 && ContainerIsLHS) ||
        (OpCode == BinaryOperatorKind::BO_LE && Value == 0 && !ContainerIsLHS))
      return;

    // Do not warn for size > 1, 1 < size, size <= 1, 1 >= size.
    if (Value == 1) {
      if ((OpCode == BinaryOperatorKind::BO_GT && ContainerIsLHS) ||
          (OpCode == BinaryOperatorKind::BO_LT && !ContainerIsLHS))
        return;
      if ((OpCode == BinaryOperatorKind::BO_LE && ContainerIsLHS) ||
          (OpCode == BinaryOperatorKind::BO_GE && !ContainerIsLHS))
        return;
    }

    if (OpCode == BinaryOperatorKind::BO_NE && Value == 0)
      Negation = true;
    if ((OpCode == BinaryOperatorKind::BO_GT ||
         OpCode == BinaryOperatorKind::BO_GE) &&
        ContainerIsLHS)
      Negation = true;
    if ((OpCode == BinaryOperatorKind::BO_LT ||
         OpCode == BinaryOperatorKind::BO_LE) &&
        !ContainerIsLHS)
      Negation = true;

    if (Negation)
      ReplacementText = "!" + ReplacementText;
    Hint = FixItHint::CreateReplacement(BinaryOp->getSourceRange(),
                                        ReplacementText);

  } else {
    // If there is a conversion above the size call to bool, it is safe to just
    // replace size with empty.
    if (const auto *UnaryOp =
            Result.Nodes.getNodeAs<UnaryOperator>("NegOnSize"))
      Hint = FixItHint::CreateReplacement(UnaryOp->getSourceRange(),
                                          ReplacementText);
    else
      Hint = FixItHint::CreateReplacement(MemberCall->getSourceRange(),
                                          "!" + ReplacementText);
  }

  diag(MemberCall->getLocStart(), "the 'empty' method should be used to check "
                                  "for emptiness instead of 'size'")
      << Hint;

  const auto *Container = Result.Nodes.getNodeAs<NamedDecl>("container");
  const auto *Empty = Result.Nodes.getNodeAs<FunctionDecl>("empty");

  diag(Empty->getLocation(), "method %0::empty() defined here",
       DiagnosticIDs::Note)
      << Container;
}
void ProTypeCstyleCastCheck::check(const MatchFinder::MatchResult &Result) {
  const auto *MatchedCast = Result.Nodes.getNodeAs<CStyleCastExpr>("cast");

  if (MatchedCast->getCastKind() == CK_BitCast ||
      MatchedCast->getCastKind() == CK_LValueBitCast ||
      MatchedCast->getCastKind() == CK_IntegralToPointer ||
      MatchedCast->getCastKind() == CK_PointerToIntegral ||
      MatchedCast->getCastKind() == CK_ReinterpretMemberPointer) {
    diag(MatchedCast->getLocStart(),
         "do not use C-style cast to convert between unrelated types");
    return;
  }

  QualType SourceType = MatchedCast->getSubExpr()->getType();

  if (MatchedCast->getCastKind() == CK_BaseToDerived) {
    const auto *SourceDecl = SourceType->getPointeeCXXRecordDecl();
    if (!SourceDecl) // The cast is from object to reference.
      SourceDecl = SourceType->getAsCXXRecordDecl();
    if (!SourceDecl)
      return;

    if (SourceDecl->isPolymorphic()) {
      // Leave type spelling exactly as it was (unlike
      // getTypeAsWritten().getAsString() which would spell enum types 'enum
      // X').
      StringRef DestTypeString = Lexer::getSourceText(
          CharSourceRange::getTokenRange(
              MatchedCast->getLParenLoc().getLocWithOffset(1),
              MatchedCast->getRParenLoc().getLocWithOffset(-1)),
          *Result.SourceManager, getLangOpts());

      auto diag_builder = diag(
          MatchedCast->getLocStart(),
          "do not use C-style cast to downcast from a base to a derived class; "
          "use dynamic_cast instead");

      const Expr *SubExpr =
          MatchedCast->getSubExprAsWritten()->IgnoreImpCasts();
      std::string CastText = ("dynamic_cast<" + DestTypeString + ">").str();
      if (!isa<ParenExpr>(SubExpr)) {
        CastText.push_back('(');
        diag_builder << FixItHint::CreateInsertion(
            Lexer::getLocForEndOfToken(SubExpr->getLocEnd(), 0,
                                       *Result.SourceManager, getLangOpts()),
            ")");
      }
      auto ParenRange = CharSourceRange::getTokenRange(
          MatchedCast->getLParenLoc(), MatchedCast->getRParenLoc());
      diag_builder << FixItHint::CreateReplacement(ParenRange, CastText);
    } else {
      diag(
          MatchedCast->getLocStart(),
          "do not use C-style cast to downcast from a base to a derived class");
    }
    return;
  }

  if (MatchedCast->getCastKind() == CK_NoOp &&
      needsConstCast(SourceType, MatchedCast->getType())) {
    diag(MatchedCast->getLocStart(),
         "do not use C-style cast to cast away constness");
  }
}
void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) {
  const auto *CastExpr = Result.Nodes.getNodeAs<CStyleCastExpr>("cast");

  // Ignore casts in macros.
  if (CastExpr->getExprLoc().isMacroID())
    return;

  // Casting to void is an idiomatic way to mute "unused variable" and similar
  // warnings.
  if (CastExpr->getCastKind() == CK_ToVoid)
    return;

  auto isFunction = [](QualType T) {
    T = T.getCanonicalType().getNonReferenceType();
    return T->isFunctionType() || T->isFunctionPointerType() ||
           T->isMemberFunctionPointerType();
  };

  const QualType DestTypeAsWritten =
      CastExpr->getTypeAsWritten().getUnqualifiedType();
  const QualType SourceTypeAsWritten =
      CastExpr->getSubExprAsWritten()->getType().getUnqualifiedType();
  const QualType SourceType = SourceTypeAsWritten.getCanonicalType();
  const QualType DestType = DestTypeAsWritten.getCanonicalType();

  auto ReplaceRange = CharSourceRange::getCharRange(
      CastExpr->getLParenLoc(), CastExpr->getSubExprAsWritten()->getBeginLoc());

  bool FnToFnCast =
      isFunction(SourceTypeAsWritten) && isFunction(DestTypeAsWritten);

  if (CastExpr->getCastKind() == CK_NoOp && !FnToFnCast) {
    // Function pointer/reference casts may be needed to resolve ambiguities in
    // case of overloaded functions, so detection of redundant casts is trickier
    // in this case. Don't emit "redundant cast" warnings for function
    // pointer/reference types.
    if (SourceTypeAsWritten == DestTypeAsWritten) {
      diag(CastExpr->getBeginLoc(), "redundant cast to the same type")
          << FixItHint::CreateRemoval(ReplaceRange);
      return;
    }
  }

  // The rest of this check is only relevant to C++.
  // We also disable it for Objective-C++.
  if (!getLangOpts().CPlusPlus || getLangOpts().ObjC1 || getLangOpts().ObjC2)
    return;
  // Ignore code inside extern "C" {} blocks.
  if (!match(expr(hasAncestor(linkageSpecDecl())), *CastExpr, *Result.Context)
           .empty())
    return;
  // Ignore code in .c files and headers included from them, even if they are
  // compiled as C++.
  if (getCurrentMainFile().endswith(".c"))
    return;

  SourceManager &SM = *Result.SourceManager;

  // Ignore code in .c files #included in other files (which shouldn't be done,
  // but people still do this for test and other purposes).
  if (SM.getFilename(SM.getSpellingLoc(CastExpr->getBeginLoc())).endswith(".c"))
    return;

  // Leave type spelling exactly as it was (unlike
  // getTypeAsWritten().getAsString() which would spell enum types 'enum X').
  StringRef DestTypeString =
      Lexer::getSourceText(CharSourceRange::getTokenRange(
                               CastExpr->getLParenLoc().getLocWithOffset(1),
                               CastExpr->getRParenLoc().getLocWithOffset(-1)),
                           SM, getLangOpts());

  auto Diag =
      diag(CastExpr->getBeginLoc(), "C-style casts are discouraged; use %0");

  auto ReplaceWithCast = [&](std::string CastText) {
    const Expr *SubExpr = CastExpr->getSubExprAsWritten()->IgnoreImpCasts();
    if (!isa<ParenExpr>(SubExpr)) {
      CastText.push_back('(');
      Diag << FixItHint::CreateInsertion(
          Lexer::getLocForEndOfToken(SubExpr->getEndLoc(), 0, SM,
                                     getLangOpts()),
          ")");
    }
    Diag << FixItHint::CreateReplacement(ReplaceRange, CastText);
  };
  auto ReplaceWithNamedCast = [&](StringRef CastType) {
    Diag << CastType;
    ReplaceWithCast((CastType + "<" + DestTypeString + ">").str());
  };

  // Suggest appropriate C++ cast. See [expr.cast] for cast notation semantics.
  switch (CastExpr->getCastKind()) {
  case CK_FunctionToPointerDecay:
    ReplaceWithNamedCast("static_cast");
    return;
  case CK_ConstructorConversion:
    if (!CastExpr->getTypeAsWritten().hasQualifiers() &&
        DestTypeAsWritten->isRecordType() &&
        !DestTypeAsWritten->isElaboratedTypeSpecifier()) {
      Diag << "constructor call syntax";
      // FIXME: Validate DestTypeString, maybe.
      ReplaceWithCast(DestTypeString.str());
    } else {
      ReplaceWithNamedCast("static_cast");
    }
    return;
  case CK_NoOp:
    if (FnToFnCast) {
      ReplaceWithNamedCast("static_cast");
      return;
    }
    if (SourceType == DestType) {
      Diag << "static_cast (if needed, the cast may be redundant)";
      ReplaceWithCast(("static_cast<" + DestTypeString + ">").str());
      return;
    }
    if (needsConstCast(SourceType, DestType) &&
        pointedUnqualifiedTypesAreEqual(SourceType, DestType)) {
      ReplaceWithNamedCast("const_cast");
      return;
    }
    if (DestType->isReferenceType()) {
      QualType Dest = DestType.getNonReferenceType();
      QualType Source = SourceType.getNonReferenceType();
      if (Source == Dest.withConst() ||
          SourceType.getNonReferenceType() == DestType.getNonReferenceType()) {
        ReplaceWithNamedCast("const_cast");
        return;
      }
      break;
    }
  // FALLTHROUGH
  case clang::CK_IntegralCast:
    // Convert integral and no-op casts between builtin types and enums to
    // static_cast. A cast from enum to integer may be unnecessary, but it's
    // still retained.
    if ((SourceType->isBuiltinType() || SourceType->isEnumeralType()) &&
        (DestType->isBuiltinType() || DestType->isEnumeralType())) {
      ReplaceWithNamedCast("static_cast");
      return;
    }
    break;
  case CK_BitCast:
    // FIXME: Suggest const_cast<...>(reinterpret_cast<...>(...)) replacement.
    if (!needsConstCast(SourceType, DestType)) {
      if (SourceType->isVoidPointerType())
        ReplaceWithNamedCast("static_cast");
      else
        ReplaceWithNamedCast("reinterpret_cast");
      return;
    }
    break;
  default:
    break;
  }

  Diag << "static_cast/const_cast/reinterpret_cast";
}
void UseUsingCheck::registerMatchers(MatchFinder *Finder) {
  if (!getLangOpts().CPlusPlus11)
    return;
  Finder->addMatcher(typedefDecl().bind("typedef"), this);
}
void ExplicitConstructorCheck::check(const MatchFinder::MatchResult &Result) {
  constexpr char WarningMessage[] =
      "%0 must be marked explicit to avoid unintentional implicit conversions";

  if (const auto *Conversion =
      Result.Nodes.getNodeAs<CXXConversionDecl>("conversion")) {
    if (Conversion->isOutOfLine())
      return;
    SourceLocation Loc = Conversion->getLocation();
    // Ignore all macros until we learn to ignore specific ones (e.g. used in
    // gmock to define matchers).
    if (Loc.isMacroID())
      return;
    diag(Loc, WarningMessage)
        << Conversion << FixItHint::CreateInsertion(Loc, "explicit ");
    return;
  }

  const auto *Ctor = Result.Nodes.getNodeAs<CXXConstructorDecl>("ctor");
  if (Ctor->isOutOfLine() || Ctor->getNumParams() == 0 ||
      Ctor->getMinRequiredArguments() > 1)
    return;

  bool takesInitializerList = isStdInitializerList(
      Ctor->getParamDecl(0)->getType().getNonReferenceType());
  if (Ctor->isExplicit() &&
      (Ctor->isCopyOrMoveConstructor() || takesInitializerList)) {
    auto isKWExplicit = [](const Token &Tok) {
      return Tok.is(tok::raw_identifier) &&
             Tok.getRawIdentifier() == "explicit";
    };
    SourceRange ExplicitTokenRange =
        FindToken(*Result.SourceManager, getLangOpts(),
                  Ctor->getOuterLocStart(), Ctor->getEndLoc(), isKWExplicit);
    StringRef ConstructorDescription;
    if (Ctor->isMoveConstructor())
      ConstructorDescription = "move";
    else if (Ctor->isCopyConstructor())
      ConstructorDescription = "copy";
    else
      ConstructorDescription = "initializer-list";

    auto Diag = diag(Ctor->getLocation(),
                     "%0 constructor should not be declared explicit")
                << ConstructorDescription;
    if (ExplicitTokenRange.isValid()) {
      Diag << FixItHint::CreateRemoval(
          CharSourceRange::getCharRange(ExplicitTokenRange));
    }
    return;
  }

  if (Ctor->isExplicit() || Ctor->isCopyOrMoveConstructor() ||
      takesInitializerList)
    return;

  bool SingleArgument =
      Ctor->getNumParams() == 1 && !Ctor->getParamDecl(0)->isParameterPack();
  SourceLocation Loc = Ctor->getLocation();
  diag(Loc, WarningMessage)
      << (SingleArgument
              ? "single-argument constructors"
              : "constructors that are callable with a single argument")
      << FixItHint::CreateInsertion(Loc, "explicit ");
}