llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: None (mahtohappy) <details> <summary>Changes</summary> --- Full diff: https://github.com/llvm/llvm-project/pull/81056.diff 4 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+2) - (modified) clang/lib/Sema/SemaDeclCXX.cpp (+19) - (modified) clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp (+3) - (added) clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp (+18) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 52a48c750fe55..1d278fe032d26 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -150,6 +150,8 @@ Improvements to Clang's diagnostics - Clang now diagnoses member template declarations with multiple declarators. - Clang now diagnoses use of the ``template`` keyword after declarative nested name specifiers. +- Clang now diagnoses constexpr constructor for not initializing atleast one member +- Fixes(`#46689 Constexpr constructor not initializing a union member is not diagnosed`) Improvements to Clang's time-trace ---------------------------------- diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index ab8a967b06a45..940d407be808a 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -2393,6 +2393,25 @@ static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl, Kind)) return false; } + } else if (!Constructor->isDelegatingConstructor()) { + for (const Decl *decl : RD->decls()) { + if (const auto *inner = dyn_cast<CXXRecordDecl>(decl)) { + if (inner->isUnion()) { + if (Constructor->getNumCtorInitializers() == 0 && + RD->hasVariantMembers()) { + if (Kind == Sema::CheckConstexprKind::Diagnose) { + SemaRef.Diag( + Dcl->getLocation(), + SemaRef.getLangOpts().CPlusPlus20 + ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init + : diag::ext_constexpr_union_ctor_no_init); + } else if (!SemaRef.getLangOpts().CPlusPlus20) { + return false; + } + } + } + } + } } } else { if (ReturnStmts.empty()) { diff --git a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp index f1f677ebfcd34..0d9b4d740a7c1 100644 --- a/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp +++ b/clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p4.cpp @@ -224,6 +224,9 @@ struct TemplateInit { }; // FIXME: This is ill-formed (no diagnostic required). We should diagnose it. constexpr TemplateInit() {} // desired-error {{must initialize all members}} +#ifndef CXX2A + // expected-error@226 {{constexpr union constructor that does not initialize any member is a C++20 extension}} +#endif }; template<typename T> struct TemplateInit2 { Literal l; diff --git a/clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp b/clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp new file mode 100644 index 0000000000000..1300641f28f1c --- /dev/null +++ b/clang/test/SemaCXX/constexpr-union-temp-ctor-cxx.cpp @@ -0,0 +1,18 @@ +// RUN: %clang_cc1 -std=c++14 -verify -fcxx-exceptions -Werror=c++14-extensions -Werror=c++20-extensions %s + +template <class> struct C { + union { + int i; + }; + constexpr C() {} // expected-error {{constexpr union constructor that does not initialize any member is a C++20 extension}} +}; +constexpr C<int> c; + +template <class> class D { + union { + int i; + }; +public: + constexpr D() {} // expected-error {{constexpr union constructor that does not initialize any member is a C++20 extension}} +}; +constexpr D<int> d; \ No newline at end of file `````````` </details> https://github.com/llvm/llvm-project/pull/81056 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
