https://github.com/Endilll created https://github.com/llvm/llvm-project/pull/87737
This is a follow-up to #81506. Since `__is_layout_compatible()` is a C++ intrinsic (https://github.com/llvm/llvm-project/blob/ff1e72d68d1224271801ff5192a8c14fbd3be83b/clang/include/clang/Basic/TokenKinds.def#L523), I don't think we should define how it interacts with VLA extension unless we have a compelling reason to. Since #81506 was merged after 18 cut-off, we don't have to follow any kind of deprecation process. >From ef24f642ca78d357018d6023fb3d9011f115299b Mon Sep 17 00:00:00 2001 From: Vlad Serebrennikov <serebrennikov.vladis...@gmail.com> Date: Fri, 5 Apr 2024 06:22:35 +0300 Subject: [PATCH] [clang] Reject VLAs in `__is_layout_compatible()` This is a follow-up to #81506. Since `__is_layout_compatible()` is a C++ intrinsic (https://github.com/llvm/llvm-project/blob/ff1e72d68d1224271801ff5192a8c14fbd3be83b/clang/include/clang/Basic/TokenKinds.def#L523), I don't think we should define how it interacts with VLA extension unless we have a compelling reason to. Since #81506 was merged after 18 cut-off, we don't have to follow any kind of deprecation process. --- clang/lib/Sema/SemaExprCXX.cpp | 3 +++ clang/test/SemaCXX/type-traits.cpp | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp index 76bb78aa8b5458..db84f181012268 100644 --- a/clang/lib/Sema/SemaExprCXX.cpp +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -6026,6 +6026,9 @@ static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, return false; } case BTT_IsLayoutCompatible: { + if (LhsT->isVariableArrayType() || RhsT->isVariableArrayType()) + Self.Diag(KeyLoc, diag::err_vla_unsupported) + << 1 << tok::kw___is_layout_compatible; return Self.IsLayoutCompatible(LhsT, RhsT); } default: llvm_unreachable("not a BTT"); diff --git a/clang/test/SemaCXX/type-traits.cpp b/clang/test/SemaCXX/type-traits.cpp index 14ec17989ec7c7..28653e82e5a16e 100644 --- a/clang/test/SemaCXX/type-traits.cpp +++ b/clang/test/SemaCXX/type-traits.cpp @@ -1741,8 +1741,10 @@ void is_layout_compatible(int n) static_assert(!__is_layout_compatible(unsigned char, signed char)); static_assert(__is_layout_compatible(int[], int[])); static_assert(__is_layout_compatible(int[2], int[2])); - static_assert(!__is_layout_compatible(int[n], int[2])); // FIXME: VLAs should be rejected - static_assert(!__is_layout_compatible(int[n], int[n])); // FIXME: VLAs should be rejected + static_assert(!__is_layout_compatible(int[n], int[2])); + // expected-error@-1 {{variable length arrays are not supported for '__is_layout_compatible'}} + static_assert(!__is_layout_compatible(int[n], int[n])); + // expected-error@-1 {{variable length arrays are not supported for '__is_layout_compatible'}} static_assert(__is_layout_compatible(int&, int&)); static_assert(!__is_layout_compatible(int&, char&)); static_assert(__is_layout_compatible(void(int), void(int))); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
