text: //===--- NoexceptMoveConstructorCheck.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 "NoexceptMoveConstructorCheck.h"
  #include "clang/AST/ASTContext.h"
  #include "clang/ASTMatchers/ASTMatchFinder.h"
  #include "clang/Lex/Lexer.h"
  #include "clang/Tooling/FixIt.h"
  
  using namespace clang::ast_matchers;
  
  namespace clang {
  namespace tidy {
  namespace performance {
  
  void NoexceptMoveConstructorCheck::registerMatchers(MatchFinder *Finder) {
    Finder->addMatcher(
        cxxMethodDecl(anyOf(cxxConstructorDecl(), hasOverloadedOperatorName("=")),
                      unless(isImplicit()), unless(isDeleted()))
            .bind("decl"),
        this);
  }
  
  void NoexceptMoveConstructorCheck::check(
      const MatchFinder::MatchResult &Result) {
    if (const auto *Decl = Result.Nodes.getNodeAs<CXXMethodDecl>("decl")) {
      StringRef MethodType = "assignment operator";
      if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(Decl)) {
        if (!Ctor->isMoveConstructor())
          return;
        MethodType = "constructor";
      } else if (!Decl->isMoveAssignmentOperator()) {
        return;
      }
  
      const auto *ProtoType = Decl->getType()->getAs<FunctionProtoType>();
  
      if (isUnresolvedExceptionSpec(ProtoType->getExceptionSpecType()))
        return;
  
      if (!isNoexceptExceptionSpec(ProtoType->getExceptionSpecType())) {
        auto Diag =
            diag(Decl->getLocation(), "move %0s should be marked noexcept")
            << MethodType;
        // Add FixIt hints.
        SourceManager &SM = *Result.SourceManager;
        assert(Decl->getNumParams() > 0);
        SourceLocation NoexceptLoc = Decl->getParamDecl(Decl->getNumParams() - 1)
                                         ->getSourceRange()
                                         .getEnd();
        if (NoexceptLoc.isValid())
          NoexceptLoc = Lexer::findLocationAfterToken(
              NoexceptLoc, tok::r_paren, SM, Result.Context->getLangOpts(), true);
        if (NoexceptLoc.isValid())
          Diag << FixItHint::CreateInsertion(NoexceptLoc, " noexcept ");
        return;
      }
  
      // Don't complain about nothrow(false), but complain on nothrow(expr)
      // where expr evaluates to false.
      if (ProtoType->canThrow() == CT_Can) {
        Expr *E = ProtoType->getNoexceptExpr();
        E = E->IgnoreImplicit();
        if (!isa<CXXBoolLiteralExpr>(E)) {
          diag(E->getExprLoc(),
               "noexcept specifier on the move %0 evaluates to 'false'")
              << MethodType;
        }
      }
    }
  }
  
  } // namespace performance
  } // namespace tidy
  } // namespace clang
  