tree pargs = template_parms_level_to_args (parm_parms);
- /* PARM, and thus the context in which we are passing ARG to it, may be
- at a deeper level than ARG; when trying to coerce to ARG_PARMS, we
- want to provide the right number of levels, so we reduce the number of
- levels in OUTER_ARGS before prepending them. This is most important
- when ARG is a namespace-scope template, as in alias-decl-ttp2.C.
-
- ARG might also be deeper than PARM (ttp23). In that case, we include
- all of OUTER_ARGS. The missing levels seem potentially problematic,
- but I can't come up with a testcase that breaks. */
- if (int arg_outer_levs = TMPL_PARMS_DEPTH (arg_parms_full) - 1)
- {
- auto x = make_temp_override (TREE_VEC_LENGTH (outer_args));
- if (TMPL_ARGS_DEPTH (outer_args) > arg_outer_levs)
- TREE_VEC_LENGTH (outer_args) = arg_outer_levs;
- pargs = add_to_template_args (outer_args, pargs);
- }
+ /* PARM and ARG might be at different template depths, and we want to
+ pass the right additional levels of args when coercing PARGS to
+ ARG_PARMS in case we need to do any substitution into non-type
+ template parameter types.
+
+ OUTER_ARGS are not the right outer levels in this case, as they are
+ the args we're building up for PARM, and for the coercion we want the
+ args for ARG. If DECL_CONTEXT isn't set for a template template
+ parameter, we can assume that it's in the current scope. In that case
+ we might end up adding more levels than needed, but that shouldn't be
+ a problem; any args we need to refer to are at the right level. */
+ tree ctx = DECL_CONTEXT (arg_tmpl);
+ if (!ctx && DECL_TEMPLATE_TEMPLATE_PARM_P (arg_tmpl))
+ ctx = current_scope ();
+ tree scope_args = NULL_TREE;
+ if (tree tinfo = get_template_info (ctx))
+ scope_args = TI_ARGS (tinfo);
+ pargs = add_to_template_args (scope_args, pargs);
pargs = coerce_template_parms (arg_parms, pargs, NULL_TREE, tf_none);
if (pargs != error_mark_node)