This is a little different. It's not an empty structural type, it's a children with zero size, that has an implicit representation (swift uses tagged bits to represent cases in an enumeration, hence IRGen says the size of the type is zero). I don't think there's any equivalent of this in C++, but I might be wrong, so I'll give this a try, but no promises I'll succeed.
-- Davide On Tue, Oct 23, 2018 at 2:21 AM Raphael Isemann via lldb-commits <lldb-commits@lists.llvm.org> wrote: > > You maybe able to add a test for that in C++: Clang types can have 0 > size, the padding from 0 to 1 happens in the CodeGen IIRC. See also > this bug: https://bugs.llvm.org/show_bug.cgi?id=31612 > > - Raphael > Am Di., 23. Okt. 2018 um 02:33 Uhr schrieb Davide Italiano via > lldb-commits <lldb-commits@lists.llvm.org>: > > > > Author: davide > > Date: Mon Oct 22 17:31:46 2018 > > New Revision: 344982 > > > > URL: http://llvm.org/viewvc/llvm-project?rev=344982&view=rev > > Log: > > [ValueObject] Stop assuming types are non-zero sized. > > > > Some backends might violate this assumption. No test case > > upstream unfortunately as this is not the case with C++, > > but I'm going to add a test in swift language support. > > > > <rdar://problem/40962410> > > > > Modified: > > lldb/trunk/source/Core/ValueObjectConstResultImpl.cpp > > > > Modified: lldb/trunk/source/Core/ValueObjectConstResultImpl.cpp > > URL: > > http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Core/ValueObjectConstResultImpl.cpp?rev=344982&r1=344981&r2=344982&view=diff > > ============================================================================== > > --- lldb/trunk/source/Core/ValueObjectConstResultImpl.cpp (original) > > +++ lldb/trunk/source/Core/ValueObjectConstResultImpl.cpp Mon Oct 22 > > 17:31:46 2018 > > @@ -77,7 +77,13 @@ ValueObject *ValueObjectConstResultImpl: > > ignore_array_bounds, child_name_str, child_byte_size, > > child_byte_offset, > > child_bitfield_bit_size, child_bitfield_bit_offset, > > child_is_base_class, > > child_is_deref_of_parent, m_impl_backend, language_flags); > > - if (child_compiler_type && child_byte_size) { > > + > > + // One might think we should check that the size of the children > > + // is always strictly positive, hence we could avoid creating a > > + // ValueObject if that's not the case, but it turns out there > > + // are languages out there which allow zero-size types with > > + // children (e.g. Swift). > > + if (child_compiler_type) { > > if (synthetic_index) > > child_byte_offset += child_byte_size * synthetic_index; > > > > > > > > _______________________________________________ > > lldb-commits mailing list > > lldb-commits@lists.llvm.org > > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits > _______________________________________________ > lldb-commits mailing list > lldb-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
