clang-tools  14.0.0git
UnconventionalAssignOperatorCheck.cpp
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1 //===--- UnconventionalAssignOperatorCheck.cpp - clang-tidy -----*- C++ -*-===//
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 
10 #include "clang/ASTMatchers/ASTMatchFinder.h"
11 #include "clang/ASTMatchers/ASTMatchers.h"
12 
13 using namespace clang::ast_matchers;
14 
15 namespace clang {
16 namespace tidy {
17 namespace misc {
18 
19 void UnconventionalAssignOperatorCheck::registerMatchers(
20  ast_matchers::MatchFinder *Finder) {
21  const auto HasGoodReturnType = cxxMethodDecl(returns(lValueReferenceType(
22  pointee(unless(isConstQualified()),
23  anyOf(autoType(), hasDeclaration(equalsBoundNode("class")))))));
24 
25  const auto IsSelf = qualType(
26  anyOf(hasDeclaration(equalsBoundNode("class")),
27  referenceType(pointee(hasDeclaration(equalsBoundNode("class"))))));
28  const auto IsAssign =
29  cxxMethodDecl(unless(anyOf(isDeleted(), isPrivate(), isImplicit())),
30  hasName("operator="), ofClass(recordDecl().bind("class")))
31  .bind("method");
32  const auto IsSelfAssign =
33  cxxMethodDecl(IsAssign, hasParameter(0, parmVarDecl(hasType(IsSelf))))
34  .bind("method");
35 
36  Finder->addMatcher(
37  cxxMethodDecl(IsAssign, unless(HasGoodReturnType)).bind("ReturnType"),
38  this);
39 
40  const auto BadSelf = referenceType(
41  anyOf(lValueReferenceType(pointee(unless(isConstQualified()))),
42  rValueReferenceType(pointee(isConstQualified()))));
43 
44  Finder->addMatcher(
45  cxxMethodDecl(IsSelfAssign,
46  hasParameter(0, parmVarDecl(hasType(BadSelf))))
47  .bind("ArgumentType"),
48  this);
49 
50  Finder->addMatcher(
51  cxxMethodDecl(IsSelfAssign, anyOf(isConst(), isVirtual())).bind("cv"),
52  this);
53 
54  const auto IsBadReturnStatement = returnStmt(unless(has(ignoringParenImpCasts(
55  anyOf(unaryOperator(hasOperatorName("*"), hasUnaryOperand(cxxThisExpr())),
56  cxxOperatorCallExpr(argumentCountIs(1),
57  callee(unresolvedLookupExpr()),
58  hasArgument(0, cxxThisExpr())),
59  cxxOperatorCallExpr(
60  hasOverloadedOperatorName("="),
61  hasArgument(
62  0, unaryOperator(hasOperatorName("*"),
63  hasUnaryOperand(cxxThisExpr())))))))));
64  const auto IsGoodAssign = cxxMethodDecl(IsAssign, HasGoodReturnType);
65 
66  Finder->addMatcher(returnStmt(IsBadReturnStatement, forFunction(IsGoodAssign))
67  .bind("returnStmt"),
68  this);
69 }
70 
72  const MatchFinder::MatchResult &Result) {
73  if (const auto *RetStmt = Result.Nodes.getNodeAs<ReturnStmt>("returnStmt")) {
74  diag(RetStmt->getBeginLoc(), "operator=() should always return '*this'");
75  } else {
76  const auto *Method = Result.Nodes.getNodeAs<CXXMethodDecl>("method");
77  if (Result.Nodes.getNodeAs<CXXMethodDecl>("ReturnType"))
78  diag(Method->getBeginLoc(), "operator=() should return '%0&'")
79  << Method->getParent()->getName();
80  if (Result.Nodes.getNodeAs<CXXMethodDecl>("ArgumentType"))
81  diag(Method->getBeginLoc(),
82  "operator=() should take '%0 const&'%select{|, '%0&&'}1 or '%0'")
83  << Method->getParent()->getName() << getLangOpts().CPlusPlus11;
84  if (Result.Nodes.getNodeAs<CXXMethodDecl>("cv"))
85  diag(Method->getBeginLoc(),
86  "operator=() should not be marked '%select{const|virtual}0'")
87  << !Method->isConst();
88  }
89 }
90 
91 } // namespace misc
92 } // namespace tidy
93 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::clangd::check
bool check(llvm::StringRef File, llvm::function_ref< bool(const Position &)> ShouldCheckLine, const ThreadsafeFS &TFS, const ClangdLSPServer::Options &Opts, bool EnableCodeCompletion)
Definition: Check.cpp:259
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
UnconventionalAssignOperatorCheck.h