On Sat, Jun 22, 2024 at 8:57 PM Andi Kleen <a...@linux.intel.com> wrote:
>
> It does nothing currently since statement attributes are handled
> directly in the parser.
Is this needed at all? a "'musttail' attribute ignored" diagnostic isn't
much more helpful than "'foo' attribute directive ignored"? Or does
stmt attribute parsing rely on this table as well?
Richard.
> gcc/c-family/ChangeLog:
>
> * c-attribs.cc (handle_musttail_attribute): Add.
> * c-common.h (handle_musttail_attribute): Add.
> ---
> gcc/c-family/c-attribs.cc | 15 +++++++++++++++
> gcc/c-family/c-common.h | 1 +
> 2 files changed, 16 insertions(+)
>
> diff --git a/gcc/c-family/c-attribs.cc b/gcc/c-family/c-attribs.cc
> index f9b229aba7fc..5adc7b775eaf 100644
> --- a/gcc/c-family/c-attribs.cc
> +++ b/gcc/c-family/c-attribs.cc
> @@ -340,6 +340,8 @@ const struct attribute_spec c_common_gnu_attributes[] =
> { "common", 0, 0, true, false, false, false,
> handle_common_attribute,
> attr_common_exclusions },
> + { "musttail", 0, 0, false, false, false,
> + false, handle_musttail_attribute, NULL },
> /* FIXME: logically, noreturn attributes should be listed as
> "false, true, true" and apply to function types. But implementing this
> would require all the places in the compiler that use TREE_THIS_VOLATILE
> @@ -1222,6 +1224,19 @@ handle_common_attribute (tree *node, tree name, tree
> ARG_UNUSED (args),
> return NULL_TREE;
> }
>
> +/* Handle a "musttail" attribute; arguments as in
> + struct attribute_spec.handler. */
> +
> +tree
> +handle_musttail_attribute (tree ARG_UNUSED (*node), tree name, tree
> ARG_UNUSED (args),
> + int ARG_UNUSED (flags), bool *no_add_attrs)
> +{
> + /* Currently only a statement attribute, handled directly in parser. */
> + warning (OPT_Wattributes, "%qE attribute ignored", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> +}
> +
> /* Handle a "noreturn" attribute; arguments as in
> struct attribute_spec.handler. */
>
> diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> index 48c89b603bcd..e84c9c47513b 100644
> --- a/gcc/c-family/c-common.h
> +++ b/gcc/c-family/c-common.h
> @@ -1643,6 +1643,7 @@ extern tree find_tm_attribute (tree);
> extern const struct attribute_spec::exclusions attr_cold_hot_exclusions[];
> extern const struct attribute_spec::exclusions attr_noreturn_exclusions[];
> extern tree handle_noreturn_attribute (tree *, tree, tree, int, bool *);
> +extern tree handle_musttail_attribute (tree *, tree, tree, int, bool *);
> extern bool has_attribute (location_t, tree, tree, tree (*)(tree));
> extern tree build_attr_access_from_parms (tree, bool);
>
> --
> 2.45.2
>
