On Wed, Feb 17, 2021 at 09:34:34AM -0800, H.J. Lu wrote:
> -fretain-used-symols.
> +/* Add the NAME attribute to *ANODE. */
> +
> +static void
> +add_attribute (tree *anode, int flags, tree name, tree args, tree ns,
> + const bool cxx11_attr_p,
> + const struct attribute_spec *spec)
Why do you need this and can't instead do what decl_attributes does
e.g. for "noipa" attribute?
/* A "noipa" function attribute implies "noinline", "noclone" and "no_icf"
for those targets that support it. */
if (TREE_CODE (*node) == FUNCTION_DECL
&& attributes
&& lookup_attribute ("noipa", attributes) != NULL
&& lookup_attribute_spec (get_identifier ("noipa")))
{
if (lookup_attribute ("noinline", attributes) == NULL)
attributes = tree_cons (get_identifier ("noinline"), NULL, attributes);
if (lookup_attribute ("noclone", attributes) == NULL)
attributes = tree_cons (get_identifier ("noclone"), NULL, attributes);
if (lookup_attribute ("no_icf", attributes) == NULL)
attributes = tree_cons (get_identifier ("no_icf"), NULL, attributes);
}
Of course, for "used" attributes and flag_retain_used_symbols it would need
to be DECL_P, but otherwise pretty much the same thing.
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -2404,6 +2404,10 @@ frerun-loop-opt
> Common Ignore
> Does nothing. Preserved for backward compatibility.
>
> +fretain-used-symols
s/symols/symbols/ - many times in the patch.
> +@item retain
> +@cindex @code{retain} function attribute
> +This attribute is the same as the @code{used} attribute, except
> +for ELF targets that support the GNU or FreeBSD OSABIs, this attribute
I'm not sure "retain" attribute should imply "used", one can always use
__attribute__((used, retain)) if one wants both.
I think it should only imply the GC avoidance and nothing else.
Jakub
