clang-tools-extra/clang-tidy/cppcoreguidelines/AvoidConstOrRefDataMembersCheck.cpp

   1 //===--- AvoidConstOrRefDataMembersCheck.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 "AvoidConstOrRefDataMembersCheck.h"
  10 #include "clang/AST/ASTContext.h"
  11 #include "clang/ASTMatchers/ASTMatchFinder.h"
  12
  13 using namespace clang::ast_matchers;
  14
  15 namespace clang::tidy::cppcoreguidelines {
  16 namespace {
  17
  18 AST_MATCHER(FieldDecl, isMemberOfLambda) {
  19   return Node.getParent()->isLambda();
  20 }
  21
  22 struct MemberFunctionInfo {
  23   bool Declared{};
  24   bool Deleted{};
  25 };
  26
  27 struct MemberFunctionPairInfo {
  28   MemberFunctionInfo Copy{};
  29   MemberFunctionInfo Move{};
  30 };
  31
  32 MemberFunctionPairInfo getConstructorsInfo(CXXRecordDecl const &Node) {
  33   MemberFunctionPairInfo Constructors{};
  34
  35   for (CXXConstructorDecl const *Ctor : Node.ctors()) {
  36     if (Ctor->isCopyConstructor()) {
  37       Constructors.Copy.Declared = true;
  38       if (Ctor->isDeleted())
  39         Constructors.Copy.Deleted = true;
  40     }
  41     if (Ctor->isMoveConstructor()) {
  42       Constructors.Move.Declared = true;
  43       if (Ctor->isDeleted())
  44         Constructors.Move.Deleted = true;
  45     }
  46   }
  47
  48   return Constructors;
  49 }
  50
  51 MemberFunctionPairInfo getAssignmentsInfo(CXXRecordDecl const &Node) {
  52   MemberFunctionPairInfo Assignments{};
  53
  54   for (CXXMethodDecl const *Method : Node.methods()) {
  55     if (Method->isCopyAssignmentOperator()) {
  56       Assignments.Copy.Declared = true;
  57       if (Method->isDeleted())
  58         Assignments.Copy.Deleted = true;
  59     }
  60
  61     if (Method->isMoveAssignmentOperator()) {
  62       Assignments.Move.Declared = true;
  63       if (Method->isDeleted())
  64         Assignments.Move.Deleted = true;
  65     }
  66   }
  67
  68   return Assignments;
  69 }
  70
  71 AST_MATCHER(CXXRecordDecl, isCopyableOrMovable) {
  72   MemberFunctionPairInfo Constructors = getConstructorsInfo(Node);
  73   MemberFunctionPairInfo Assignments = getAssignmentsInfo(Node);
  74
  75   if (Node.hasSimpleCopyConstructor() ||
  76       (Constructors.Copy.Declared && !Constructors.Copy.Deleted))
  77     return true;
  78   if (Node.hasSimpleMoveConstructor() ||
  79       (Constructors.Move.Declared && !Constructors.Move.Deleted))
  80     return true;
  81   if (Node.hasSimpleCopyAssignment() ||
  82       (Assignments.Copy.Declared && !Assignments.Copy.Deleted))
  83     return true;
  84   if (Node.hasSimpleMoveAssignment() ||
  85       (Assignments.Move.Declared && !Assignments.Move.Deleted))
  86     return true;
  87
  88   return false;
  89 }
  90
  91 } // namespace
  92
  93 void AvoidConstOrRefDataMembersCheck::registerMatchers(MatchFinder *Finder) {
  94   Finder->addMatcher(
  95       fieldDecl(
  96           unless(isMemberOfLambda()),
  97           anyOf(
  98               fieldDecl(hasType(hasCanonicalType(referenceType()))).bind("ref"),
  99               fieldDecl(hasType(qualType(isConstQualified()))).bind("const")),
 100           hasDeclContext(cxxRecordDecl(isCopyableOrMovable()))),
 101       this);
 102 }
 103
 104 void AvoidConstOrRefDataMembersCheck::check(
 105     const MatchFinder::MatchResult &Result) {
 106   if (const auto *MatchedDecl = Result.Nodes.getNodeAs<FieldDecl>("ref"))
 107     diag(MatchedDecl->getLocation(), "member %0 of type %1 is a reference")
 108         << MatchedDecl << MatchedDecl->getType();
 109   if (const auto *MatchedDecl = Result.Nodes.getNodeAs<FieldDecl>("const"))
 110     diag(MatchedDecl->getLocation(), "member %0 of type %1 is const qualified")
 111         << MatchedDecl << MatchedDecl->getType();
 112 }
 113
 114 } // namespace clang::tidy::cppcoreguidelines