On Tue, Feb 14, 2017 at 10:05:04AM -0500, Nathan Sidwell wrote:
> On 02/13/2017 10:46 AM, Jakub Jelinek wrote:
> > Hi!
> >
> > I'd like to ping a couple of patches:
>
> > - C++ P1 PR79288 - wrong default TLS model for __thread static data members
> > http://gcc.gnu.org/ml/gcc-patches/2017-01/msg02349.html
>
> This is ok, but don't you think the changelog is misleading? In your
> description you say it needs DECL_EXTERNAL set, but the changelog says
> 'inline', which isn't something static member vars have (although I can see
> how it's involved in DECL_EXTERNAL setting).
It is something static member vars can have (explicitly or implicitly).
In 6.x we had:
/* Even if there is an in-class initialization, DECL
is considered undefined until an out-of-class
definition is provided. */
DECL_EXTERNAL (decl) = 1;
if (thread_p)
{
CP_DECL_THREAD_LOCAL_P (decl) = true;
if (!processing_template_decl)
set_decl_tls_model (decl, decl_default_tls_model (decl));
if (declspecs->gnu_thread_keyword_p)
SET_DECL_GNU_TLS_P (decl);
}
...
With the addition of C++17 inline vars I changed that to:
if (thread_p)
{
CP_DECL_THREAD_LOCAL_P (decl) = true;
if (!processing_template_decl)
set_decl_tls_model (decl, decl_default_tls_model (decl));
if (declspecs->gnu_thread_keyword_p)
SET_DECL_GNU_TLS_P (decl);
}
...
if (inlinep)
mark_inline_variable (decl);
if (!DECL_VAR_DECLARED_INLINE_P (decl)
&& !(cxx_dialect >= cxx1z && constexpr_p))
/* Even if there is an in-class initialization, DECL
is considered undefined until an out-of-class
definition is provided, unless this is an inline
variable. */
DECL_EXTERNAL (decl) = 1;
because inline static data members, explicit or implicit, really shouldn't
be marked DECL_EXTERNAL, they have in-class definition rather than a mere
declaration.
The patch just changes that back to:
...
if (inlinep)
mark_inline_variable (decl);
if (!DECL_VAR_DECLARED_INLINE_P (decl)
&& !(cxx_dialect >= cxx1z && constexpr_p))
/* Even if there is an in-class initialization, DECL
is considered undefined until an out-of-class
definition is provided, unless this is an inline
variable. */
DECL_EXTERNAL (decl) = 1;
if (thread_p)
{
CP_DECL_THREAD_LOCAL_P (decl) = true;
if (!processing_template_decl)
set_decl_tls_model (decl, decl_default_tls_model (decl));
if (declspecs->gnu_thread_keyword_p)
SET_DECL_GNU_TLS_P (decl);
}
Jakub
