https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115616
Bug ID: 115616
Summary: Friend-injecting a template function causes an ICE if
you inject after trying to instantiate that function
Product: gcc
Version: 14.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: iamsupermouse at mail dot ru
Target Milestone: ---
The following causes an internal compiler error in GCC 14 and trunk:
https://gcc.godbolt.org/z/z9PWhWvzh
Same bug in Clang: https://github.com/llvm/llvm-project/issues/96485
MSVC compiles this successfully and calls `bar<10,20>()`.
template <int X, int Y> void bar() {}
template <typename T>
struct Reader
{
template <int X>
friend void foo(Reader<T>);
};
template <typename T, int Y>
struct Writer
{
template <int X>
friend void foo(Reader<T>) {bar<X, Y>();}
};
int main()
{
foo<10>(Reader<int>{});
Writer<int, 20>{};
}
GCC says: (this is trunk, v14 just says "segmentation fault")
<source>: In instantiation of 'void foo(Reader<T>) [with int X = 10; T =
int; int Y = <missing>]':
<source>:19:12: required from here
19 | foo<10>(Reader<int>{});
| ~~~~~~~^~~~~~~~~~~~~~~
<source>:14:33: internal compiler error: tree check: accessed elt 2 of
'tree_vec' with 1 elts in tsubst, at cp/pt.cc:16362
14 | friend void foo(Reader<T>) {bar<X, Y>();}
| ^~~~~~~~~
0x26cfe8c internal_error(char const*, ...)
???:0
0x97a4bb tree_vec_elt_check_failed(int, int, char const*, int, char const*)
???:0
0xcbc689 tsubst_template_args(tree_node*, tree_node*, int, tree_node*)
???:0
0xcabce3 instantiate_decl(tree_node*, bool, bool)
???:0
0xcd625b instantiate_pending_templates(int)
???:0
0xb6e830 c_parse_final_cleanups()
???:0
0xdcad68 c_common_parse_file()
???:0
