diff options
Diffstat (limited to 'compilerplugins/clang/unreffun.cxx')
| -rw-r--r-- | compilerplugins/clang/unreffun.cxx | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/compilerplugins/clang/unreffun.cxx b/compilerplugins/clang/unreffun.cxx index bfd48b328300..629e369dadc7 100644 --- a/compilerplugins/clang/unreffun.cxx +++ b/compilerplugins/clang/unreffun.cxx @@ -51,6 +51,19 @@ Decl const * getPreviousNonFriendDecl(Decl const * decl) { } } +bool isSpecialMemberFunction(FunctionDecl const * decl) { + if (auto const ctor = dyn_cast<CXXConstructorDecl>(decl)) { + return ctor->isDefaultConstructor() || ctor->isCopyOrMoveConstructor(); + } + if (isa<CXXDestructorDecl>(decl)) { + return true; + } + if (auto const meth = dyn_cast<CXXMethodDecl>(decl)) { + return meth->isCopyAssignmentOperator() || meth->isMoveAssignmentOperator(); + } + return false; +} + class UnrefFun: public RecursiveASTVisitor<UnrefFun>, public loplugin::Plugin { public: explicit UnrefFun(loplugin::InstantiationData const & data): Plugin(data) {} @@ -141,6 +154,14 @@ bool UnrefFun::VisitFunctionDecl(FunctionDecl const * decl) { { return true; } + if (canon->isExplicitlyDefaulted() && isSpecialMemberFunction(canon)) { + // If a special member function is explicitly defaulted on the first declaration, assume + // that its presence is always due to some interface design consideration, not to explicitly + // request a definition that might be worth to flag as unused (and C++20 may extend + // defaultability beyond special member functions to comparison operators, therefore + // explicitly check here for special member functions only): + return true; + } LinkageInfo info(canon->getLinkageAndVisibility()); if (info.getLinkage() == ExternalLinkage && hasCLanguageLinkageType(canon) && canon->isDefined() |