https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109018
--- Comment #8 from qingzhe huang <nickhuang99 at hotmail dot com> ---
I gdb a little bit and I feel this issue is fixable. See the comparison of
"unq" and "function" below is not compatible because "function" is
"IDENTIFIER_NODE" and "unq" is "VIEW_CONVERT_EXPR". If we check and convert
"unq", we will find they are matching.
(gdb) info b
Num Type Disp Enb Address What
1 breakpoint keep y 0x0000000000d0bafc in
tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) at
/home/nick/Downloads/gcc-dev/gcc/gcc/cp/pt.cc:20608
breakpoint already hit 1 time
(gdb) l 20608
20603 (function, args, complain, in_decl, true,
20604 integral_constant_expression_p));
20605 if (unq == error_mark_node)
20606 RETURN (error_mark_node);
20607
20608 if (unq != function)
20609 {
20610 char const *const msg
20611 = G_("%qD was not declared in this scope, "
20612 "and no declarations were found by "
(gdb) p IDENTIFIER_POINTER(function)
$16 = 0x7ffff70c42c0 "g"
(gdb) p IDENTIFIER_POINTER(DECL_NAME(TREE_OPERAND(unq,0)))
$17 = 0x7ffff70c42c0 "g"
(gdb) p TREE_CODE(function)
$18 = IDENTIFIER_NODE
(gdb) p TREE_CODE(unq)
$19 = VIEW_CONVERT_EXPR
(gdb)
