https://github.com/Jean-Christian-Cirstea created https://github.com/llvm/llvm-project/pull/187940
Before this commit, [[maybe_unused]] on private fields was ignored. In conjunction with `-Wunused-private-field`, false warnings were emitted by clang. This commit fixes this by checking if an unused private field is annotated with [[maybe_unused]]. >From 346e1697e661bee1624a3a58701bde4c11bc7c73 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jean-Christian=20C=C3=8ERSTEA?= <[email protected]> Date: Sun, 22 Mar 2026 17:48:37 +0200 Subject: [PATCH] [Clang] Honour [[maybe_unused]] on private fields MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Before this commit, [[maybe_unused]] on private fields was ignored. In conjunction with `-Wunused-private-field`, false warnings were emitted by clang. This commit fixes this by checking if an unused private field is annotated with [[maybe_unused]]. Signed-off-by: Jean-Christian CÎRSTEA <[email protected]> --- clang/lib/Sema/Sema.cpp | 2 +- .../test/SemaCXX/warn-maybe-unused-private-field.cpp | 11 +++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) create mode 100644 clang/test/SemaCXX/warn-maybe-unused-private-field.cpp diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp index 3065b5e1e66d3..201a2714fd8a3 100644 --- a/clang/lib/Sema/Sema.cpp +++ b/clang/lib/Sema/Sema.cpp @@ -1610,7 +1610,7 @@ void Sema::ActOnEndOfTranslationUnit() { RecordCompleteMap MNCComplete; for (const NamedDecl *D : UnusedPrivateFields) { const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext()); - if (RD && !RD->isUnion() && + if (RD && !RD->isUnion() && !RD->hasAttr<UnusedAttr>() && IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) { Diag(D->getLocation(), diag::warn_unused_private_field) << D->getDeclName(); diff --git a/clang/test/SemaCXX/warn-maybe-unused-private-field.cpp b/clang/test/SemaCXX/warn-maybe-unused-private-field.cpp new file mode 100644 index 0000000000000..505c950a9fb81 --- /dev/null +++ b/clang/test/SemaCXX/warn-maybe-unused-private-field.cpp @@ -0,0 +1,11 @@ +// RUN: %clang_cc1 -fsyntax-only -Wunused-private-field -verify -std=c++17 %s +// RUN: %clang_cc1 -fsyntax-only -Wunused-private-field -verify -std=c++20 %s +// RUN: %clang_cc1 -fsyntax-only -Wunused-private-field -verify -std=c++23 %s + +class MyClass { + // Marking an unused field with [[maybe_unused]] shouldn't result in a + // warning + [[maybe_unused]] + unsigned field1; + signed field2; // expected-warning{{private field 'field2' is not used}} +}; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
