xref: /llvm-project/clang-tools-extra/clang-tidy/fuchsia/TrailingReturnCheck.cpp (revision 7d2ea6c422d3f5712b7253407005e1a465a76946)
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::tidy::fuchsia {
17 
registerMatchers(MatchFinder * Finder)18 void TrailingReturnCheck::registerMatchers(MatchFinder *Finder) {
19   // Functions that have trailing returns are disallowed, except for those
20   // using decltype specifiers and lambda with otherwise unutterable
21   // return types.
22   Finder->addMatcher(
23       functionDecl(hasTrailingReturn(),
24                    unless(anyOf(returns(decltypeType()),
25                                 hasParent(cxxRecordDecl(isLambda())),
26                                 cxxDeductionGuideDecl())))
27           .bind("decl"),
28       this);
29 }
30 
check(const MatchFinder::MatchResult & Result)31 void TrailingReturnCheck::check(const MatchFinder::MatchResult &Result) {
32   if (const auto *D = Result.Nodes.getNodeAs<FunctionDecl>("decl"))
33     diag(D->getBeginLoc(),
34          "a trailing return type is disallowed for this function declaration");
35 }
36 
37 } // namespace clang::tidy::fuchsia
38