Author: Timm Baeder Date: 2025-02-18T15:36:46+01:00 New Revision: 31abb20162a7d035841c9506b1cd18d3ae8df10c
URL: https://github.com/llvm/llvm-project/commit/31abb20162a7d035841c9506b1cd18d3ae8df10c DIFF: https://github.com/llvm/llvm-project/commit/31abb20162a7d035841c9506b1cd18d3ae8df10c.diff LOG: [clang][bytecode] Move bases and virtual bases in moveRecord (#127627) The fixme comment turned out to be true. Added: Modified: clang/lib/AST/ByteCode/Descriptor.cpp clang/test/AST/ByteCode/records.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ByteCode/Descriptor.cpp b/clang/lib/AST/ByteCode/Descriptor.cpp index 319d1690c1cd0..6017f6dd61cb3 100644 --- a/clang/lib/AST/ByteCode/Descriptor.cpp +++ b/clang/lib/AST/ByteCode/Descriptor.cpp @@ -237,8 +237,7 @@ static void moveRecord(Block *B, std::byte *Src, std::byte *Dst, assert(D); assert(D->ElemRecord); - // FIXME: There might be cases where we need to move over the (v)bases as - // well. + // FIXME: Code duplication. for (const auto &F : D->ElemRecord->fields()) { auto FieldOffset = F.Offset; const auto *SrcDesc = @@ -250,6 +249,26 @@ static void moveRecord(Block *B, std::byte *Src, std::byte *Dst, if (auto Fn = F.Desc->MoveFn) Fn(B, Src + FieldOffset, Dst + FieldOffset, F.Desc); } + + for (const auto &Base : D->ElemRecord->bases()) { + auto BaseOffset = Base.Offset; + const auto *SrcDesc = + reinterpret_cast<const InlineDescriptor *>(Src + BaseOffset) - 1; + auto *DestDesc = reinterpret_cast<InlineDescriptor *>(Dst + BaseOffset) - 1; + std::memcpy(DestDesc, SrcDesc, sizeof(InlineDescriptor)); + + if (auto Fn = Base.Desc->MoveFn) + Fn(B, Src + BaseOffset, Dst + BaseOffset, Base.Desc); + } + + for (const auto &VBase : D->ElemRecord->virtual_bases()) { + auto VBaseOffset = VBase.Offset; + const auto *SrcDesc = + reinterpret_cast<const InlineDescriptor *>(Src + VBaseOffset) - 1; + auto *DestDesc = + reinterpret_cast<InlineDescriptor *>(Dst + VBaseOffset) - 1; + std::memcpy(DestDesc, SrcDesc, sizeof(InlineDescriptor)); + } } static BlockCtorFn getCtorPrim(PrimType Type) { diff --git a/clang/test/AST/ByteCode/records.cpp b/clang/test/AST/ByteCode/records.cpp index 3cc3210841e0f..a13f30cd23119 100644 --- a/clang/test/AST/ByteCode/records.cpp +++ b/clang/test/AST/ByteCode/records.cpp @@ -1715,3 +1715,22 @@ namespace IgnoredMemberExpr { }; static_assert(B{}.foo() == 0, ""); } + +#if __cplusplus >= 202002L +namespace DeadUpcast { + struct A {}; + struct B : A{}; + constexpr bool foo() { + + B *pb; + { + B b; + pb = &b; + } + A *pa = pb; + + return true; + } + static_assert(foo(), ""); +} +#endif _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
