clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.cpp

   1 //===--- TrailingReturnCheck.cpp - clang-tidy------------------------------===//
   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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "TrailingReturnCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/ASTMatchers/ASTMatchFinder.h"
  12 #include "clang/ASTMatchers/ASTMatchersInternal.h"
  13
  14 using namespace clang::ast_matchers;
  15
  16 namespace clang {
  17 namespace tidy {
  18 namespace fuchsia {
  19
  20 void TrailingReturnCheck::registerMatchers(MatchFinder *Finder) {
  21   // Functions that have trailing returns are disallowed, except for those
  22   // using decltype specifiers and lambda with otherwise unutterable
  23   // return types.
  24   Finder->addMatcher(
  25       functionDecl(hasTrailingReturn(),
  26                    unless(anyOf(returns(decltypeType()),
  27                                 hasParent(cxxRecordDecl(isLambda())),
  28                                 cxxDeductionGuideDecl())))
  29           .bind("decl"),
  30       this);
  31 }
  32
  33 void TrailingReturnCheck::check(const MatchFinder::MatchResult &Result) {
  34   if (const auto *D = Result.Nodes.getNodeAs<FunctionDecl>("decl"))
  35     diag(D->getBeginLoc(),
  36          "a trailing return type is disallowed for this function declaration");
  37 }
  38
  39 } // namespace fuchsia
  40 } // namespace tidy
  41 } // namespace clang