On Sat, Mar 18, 2023 at 08:39:45AM -0400, Jason Merrill wrote:
> On 3/17/23 13:51, Jakub Jelinek wrote:
> > The following two testcases are miscompiled, because we keep TREE_READONLY
> > on the vars even when they are (possibly) dynamically initialized by a TLS
> > wrapper function. Normally cp_finish_decl drops TREE_READONLY from vars
> > which need dynamic initialization, but for TLS we do this kind of
> > initialization upon every access to those variables.
>
> Why not handle this case in cp_finish_decl, too? That is, add
> DECL_THREAD_LOCAL_P to the TREE_STATIC check in
The patch is mostly about DECL_EXTERNAL cases, the others are supposedly
handled by the var_definition_p code there (or at least I assumed;
testcases certainly test only DECL_EXTERNAL).
I guess it could be done in cp_finish_decl, maybe better next to the
/* A reference will be modified here, as it is initialized. */
if (! DECL_EXTERNAL (decl)
&& TREE_READONLY (decl)
&& TYPE_REF_P (type))
{
was_readonly = 1;
TREE_READONLY (decl) = 0;
}
spot, but we'd need to export the decl2.cc helpers for it,
because not all DECL_THREAD_LOCAL_P vars need to be treated that way.
if (VAR_P (decl)
&& CP_DECL_THREAD_LOCAL_P (decl)
&& var_needs_tls_wrapper (decl)
&& (!DECL_EXTERNAL (decl) || flag_extern_tls_init))
TREE_READONLY (decl) = 0;
where var_needs_tls_wrapper would need to be exported from decl2.cc.
Though, var_needs_tls_wrapper -> var_defined_without_dynamic_init
needs
DECL_NONTRIVIALLY_INITIALIZED_P/DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P,
so perhaps that is accurate only closer to the end of cp_finish_decl?
Jakub
