llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Oleksandr T. (a-tarasyuk) <details> <summary>Changes</summary> Fixes #<!-- -->62472 --- Full diff: https://github.com/llvm/llvm-project/pull/120734.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/lib/Sema/SemaDeclCXX.cpp (+26-17) - (modified) clang/test/SemaCXX/warn-unused-private-field.cpp (+13) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index a85ef60b7b58ba..c1d3596140721e 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -707,6 +707,7 @@ Improvements to Clang's diagnostics } - Fix -Wdangling false positives on conditional operators (#120206). +- Clang now diagnoses unused private fields with the ``[[warn_unused]]`` attribute (#GH62472). Improvements to Clang's time-trace ---------------------------------- diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index c5a72cf812ebc9..760ed06fc1b858 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -3307,6 +3307,29 @@ void Sema::CheckShadowInheritedFields(const SourceLocation &Loc, } } +template <typename AttrType> +inline static bool HasAttribute(const QualType &T) { + if (const TagDecl *TD = T->getAsTagDecl()) + return TD->hasAttr<AttrType>(); + if (const TypedefType *TDT = T->getAs<TypedefType>()) + return TDT->getDecl()->hasAttr<AttrType>(); + return false; +} + +inline static bool IsUnusedPrivateField(FieldDecl *FD) { + if (FD->getAccess() == AS_private && FD->getDeclName()) { + QualType FieldType = FD->getType(); + if (HasAttribute<WarnUnusedAttr>(FieldType)) + return true; + + return !FD->isImplicit() && !FD->hasAttr<UnusedAttr>() && + !FD->getParent()->isDependentContext() && + !HasAttribute<UnusedAttr>(FieldType) && + !InitializationHasSideEffects(*FD); + } + return false; +} + NamedDecl * Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D, MultiTemplateParamsArg TemplateParameterLists, @@ -3589,25 +3612,11 @@ Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D, FieldDecl *FD = cast<FieldDecl>(Member); FieldCollector->Add(FD); - if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) { + if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation()) && + IsUnusedPrivateField(FD)) { // Remember all explicit private FieldDecls that have a name, no side // effects and are not part of a dependent type declaration. - - auto DeclHasUnusedAttr = [](const QualType &T) { - if (const TagDecl *TD = T->getAsTagDecl()) - return TD->hasAttr<UnusedAttr>(); - if (const TypedefType *TDT = T->getAs<TypedefType>()) - return TDT->getDecl()->hasAttr<UnusedAttr>(); - return false; - }; - - if (!FD->isImplicit() && FD->getDeclName() && - FD->getAccess() == AS_private && - !FD->hasAttr<UnusedAttr>() && - !FD->getParent()->isDependentContext() && - !DeclHasUnusedAttr(FD->getType()) && - !InitializationHasSideEffects(*FD)) - UnusedPrivateFields.insert(FD); + UnusedPrivateFields.insert(FD); } } diff --git a/clang/test/SemaCXX/warn-unused-private-field.cpp b/clang/test/SemaCXX/warn-unused-private-field.cpp index 0cc6f687f1b35f..93a285b159f740 100644 --- a/clang/test/SemaCXX/warn-unused-private-field.cpp +++ b/clang/test/SemaCXX/warn-unused-private-field.cpp @@ -329,3 +329,16 @@ class C { MaybeUnusedTypedef t; // no-warning }; } + +namespace GH62472 { +class [[gnu::warn_unused]] S { +public: + S(); +}; + +class C { +private: + const int i = 0; // expected-warning {{private field 'i' is not used}} + const S s; // expected-warning {{private field 's' is not used}} +}; +} `````````` </details> https://github.com/llvm/llvm-project/pull/120734 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
