https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108042
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2022-12-11
Ever confirmed|0 |1
CC| |hubicka at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Target Milestone|--- |10.5
Status|UNCONFIRMED |WAITING
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
t2.c:1:6: warning: 'weakref' attribute should be accompanied with an 'alias'
attribute [-Wattributes]
1 | void KNOWNNOTOBEAFUNCTION(void) __attribute__((weakref));
| ^~~~~~~~~~~~~~~~~~~~
did you want to use __attribute__((weak)) here? I think this works as
designed.
Note handle_weakref_attribute has
/* The idea here is that `weakref("name")' mutates into `weakref,
alias("name")', and weakref without arguments, in turn,
implicitly adds weak. */
if (args)
{
attr = tree_cons (get_identifier ("alias"), args, attr);
attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr);
*no_add_attrs = true;
decl_attributes (node, attr, flags);
}
else
{
if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node)))
error_at (DECL_SOURCE_LOCATION (*node),
"%qE attribute must appear before %qs attribute",
name, "alias");
/* Can't call declare_weak because it wants this to be TREE_PUBLIC,
and that isn't supported; and because it wants to add it to
the list of weak decls, which isn't helpful. */
DECL_WEAK (*node) = 1;
but then process_common_attributes does
tree weakref = lookup_attribute ("weakref", DECL_ATTRIBUTES (decl));
if (weakref && !lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
{
warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wattributes,
"%<weakref%> attribute should be accompanied with"
" an %<alias%> attribute");
DECL_WEAK (decl) = 0;
DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
DECL_ATTRIBUTES (decl));
}
this diagnostic does not match the documentation which gives the plain
'weakref' semantics of 'weak'.
