When combining -g1 with -flto we run into the DIE location annotation machinery for globals calling dwarf2out_late_global_decl but not having any early generated DIE for function scope statics. In this process we'd generate a limbo DIE since also the function scope doesn't have any early generated DIE. The limbo handling then tries to force a DIE for the context chain which ultimatively fails and ICEs at the std namespace decl because at -g1 we don't represent that.
The following avoids this situation by making sure to never generate any limbo DIEs from dwarf2out_late_global_decl in the in_lto_p path but instead for function scope globals rely on DIE generation for the function to output a DIE for the local static (which doesn't happen for -g1). I explored a lot of other options to fix this but in the end this seems to be the most spot-on fix with the least risk of unwanted effects. LTO bootstrapped on x86_64-unknown-linux-gnu (running into PR108984), bootstrapped and tested on x86_64-unknown-linux-gnu. OK? Thanks, Richard. PR debug/108772 * dwarf2out.cc (dwarf2out_late_global_decl): Do not generate a DIE for a function scope static when we do not have a DIE for the function already. * g++.dg/lto/pr108772_0.C: New testcase. --- gcc/dwarf2out.cc | 12 ++++++- gcc/testsuite/g++.dg/lto/pr108772_0.C | 46 +++++++++++++++++++++++++++ 2 files changed, 57 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/lto/pr108772_0.C diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc index 1f39df3b1e2..6f457ed4472 100644 --- a/gcc/dwarf2out.cc +++ b/gcc/dwarf2out.cc @@ -27283,7 +27283,17 @@ dwarf2out_late_global_decl (tree decl) was not enabled at compile-time or the target doesn't support the LTO early debug scheme. */ if (! die && in_lto_p) - dwarf2out_decl (decl); + { + /* Avoid relying on the ability to force context DIEs for + local entities. Instead if the function context was not + instantiated yet defer to it producing its local DIEs. + See PR108772. */ + dw_die_ref context_die = comp_unit_die (); + if (local_function_static (decl)) + context_die = lookup_decl_die (DECL_CONTEXT (decl)); + if (context_die) + dwarf2out_decl (decl); + } else if (die) { /* We get called via the symtab code invoking late_global_decl diff --git a/gcc/testsuite/g++.dg/lto/pr108772_0.C b/gcc/testsuite/g++.dg/lto/pr108772_0.C new file mode 100644 index 00000000000..81f15a90a3e --- /dev/null +++ b/gcc/testsuite/g++.dg/lto/pr108772_0.C @@ -0,0 +1,46 @@ +// { dg-lto-do link } +// { dg-require-effective-target shared } +// { dg-require-effective-target fpic } +// { dg-lto-options { "-flto -fPIC -shared -O1 -fimplicit-constexpr -g1" } } +// { dg-extra-ld-options "-shared" } + +namespace std { +struct _Sp_counted_base { + virtual void *_M_get_deleter(const int &); +}; +bool _S_eq(int); +struct _Sp_make_shared_tag { + static const int &_S_ti() { + static constexpr char __tag{}; + return reinterpret_cast<const int &>(__tag); + } +}; +struct _Impl { + _Impl(int); +}; +int _Sp_counted_ptr_inplace___a; +struct _Sp_counted_ptr_inplace : _Sp_counted_base { + _Sp_counted_ptr_inplace() : _M_impl(_Sp_counted_ptr_inplace___a) {} + void *_M_get_deleter(const int &__ti) { + auto __ptr(_M_ptr()); + &__ti == &_Sp_make_shared_tag::_S_ti() || _S_eq(__ti); + return __ptr; + } + int *_M_ptr(); + _Impl _M_impl; +}; +struct __shared_count { + __shared_count(int, int) { _Sp_counted_ptr_inplace(); } +}; +int _M_ptr; +struct __shared_ptr { + template <typename _Alloc> + __shared_ptr(_Alloc __tag) : _M_refcount(_M_ptr, __tag) {} + __shared_count _M_refcount; +}; +int shared_ptr___tag; +struct shared_ptr : __shared_ptr { + shared_ptr() : __shared_ptr(shared_ptr___tag) {} +}; +void ArgEq() { shared_ptr(); } +} // namespace std -- 2.35.3