1 //===--- TriviallyDestructibleCheck.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 "TriviallyDestructibleCheck.h"
10 #include "../utils/LexerUtils.h"
11 #include "../utils/Matchers.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14 
15 using namespace clang::ast_matchers;
16 using namespace clang::ast_matchers::internal;
17 using namespace clang::tidy::matchers;
18 
19 namespace clang {
20 namespace tidy {
21 namespace performance {
22 
23 namespace {
24 
AST_MATCHER(Decl,isFirstDecl)25 AST_MATCHER(Decl, isFirstDecl) { return Node.isFirstDecl(); }
26 
AST_MATCHER_P(CXXRecordDecl,hasBase,Matcher<QualType>,InnerMatcher)27 AST_MATCHER_P(CXXRecordDecl, hasBase, Matcher<QualType>, InnerMatcher) {
28   for (const CXXBaseSpecifier &BaseSpec : Node.bases()) {
29     QualType BaseType = BaseSpec.getType();
30     if (InnerMatcher.matches(BaseType, Finder, Builder))
31       return true;
32   }
33   return false;
34 }
35 
36 } // namespace
37 
registerMatchers(MatchFinder * Finder)38 void TriviallyDestructibleCheck::registerMatchers(MatchFinder *Finder) {
39   Finder->addMatcher(
40       cxxDestructorDecl(
41           isDefaulted(),
42           unless(anyOf(isFirstDecl(), isVirtual(),
43                        ofClass(cxxRecordDecl(
44                            anyOf(hasBase(unless(isTriviallyDestructible())),
45                                  has(fieldDecl(unless(
46                                      hasType(isTriviallyDestructible()))))))))))
47           .bind("decl"),
48       this);
49 }
50 
check(const MatchFinder::MatchResult & Result)51 void TriviallyDestructibleCheck::check(const MatchFinder::MatchResult &Result) {
52   const auto *MatchedDecl = Result.Nodes.getNodeAs<CXXDestructorDecl>("decl");
53 
54   // Get locations of both first and out-of-line declarations.
55   SourceManager &SM = *Result.SourceManager;
56   const auto *FirstDecl = cast<CXXMethodDecl>(MatchedDecl->getFirstDecl());
57   const SourceLocation FirstDeclEnd = utils::lexer::findNextTerminator(
58       FirstDecl->getEndLoc(), SM, getLangOpts());
59   const CharSourceRange SecondDeclRange = CharSourceRange::getTokenRange(
60       MatchedDecl->getBeginLoc(),
61       utils::lexer::findNextTerminator(MatchedDecl->getEndLoc(), SM,
62                                        getLangOpts()));
63   if (FirstDeclEnd.isInvalid() || SecondDeclRange.isInvalid())
64     return;
65 
66   // Report diagnostic.
67   diag(FirstDecl->getLocation(),
68        "class %0 can be made trivially destructible by defaulting the "
69        "destructor on its first declaration")
70       << FirstDecl->getParent()
71       << FixItHint::CreateInsertion(FirstDeclEnd, " = default")
72       << FixItHint::CreateRemoval(SecondDeclRange);
73   diag(MatchedDecl->getLocation(), "destructor definition is here",
74        DiagnosticIDs::Note);
75 }
76 
77 } // namespace performance
78 } // namespace tidy
79 } // namespace clang
80