Greetings All,
I was attempting to fix this bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88395#add_comment
and managed to track it down to expand_concept in constraint.cc.
Seems that we are hitting this case in tsubst_expr for the NULL_TREE:
if (t == NULL_TREE || t == error_mark_node)
return t
and we only check result for error_mark_node. Is error_mark_node
equal to a NULL_TREE or is it something else? If not than it seems
that we should change our check to:
if (result == error_mark_node || result == NULL_TREE)
and it seems that this is also not checked it the other callers so it
should be fixed.
Let me known if I am missing something,
Nick
