1 //===--- MissingHashCheck.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 "MissingHashCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 
13 using namespace clang::ast_matchers;
14 
15 namespace clang {
16 namespace tidy {
17 namespace objc {
18 
19 namespace {
20 
21 AST_MATCHER_P(ObjCImplementationDecl, hasInterface,
22               ast_matchers::internal::Matcher<ObjCInterfaceDecl>, Base) {
23   const ObjCInterfaceDecl *InterfaceDecl = Node.getClassInterface();
24   return Base.matches(*InterfaceDecl, Finder, Builder);
25 }
26 
27 AST_MATCHER_P(ObjCContainerDecl, hasInstanceMethod,
28               ast_matchers::internal::Matcher<ObjCMethodDecl>, Base) {
29   // Check each instance method against the provided matcher.
30   for (const auto *I : Node.instance_methods()) {
31     if (Base.matches(*I, Finder, Builder))
32       return true;
33   }
34   return false;
35 }
36 
37 } // namespace
38 
39 void MissingHashCheck::registerMatchers(MatchFinder *Finder) {
40   Finder->addMatcher(
41       objcMethodDecl(
42           hasName("isEqual:"), isInstanceMethod(),
43           hasDeclContext(objcImplementationDecl(
44                              hasInterface(isDirectlyDerivedFrom("NSObject")),
45                              unless(hasInstanceMethod(hasName("hash"))))
46                              .bind("impl"))),
47       this);
48 }
49 
50 void MissingHashCheck::check(const MatchFinder::MatchResult &Result) {
51   const auto *ID = Result.Nodes.getNodeAs<ObjCImplementationDecl>("impl");
52   diag(ID->getLocation(), "%0 implements -isEqual: without implementing -hash")
53       << ID;
54 }
55 
56 } // namespace objc
57 } // namespace tidy
58 } // namespace clang
59