https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117792
Bug ID: 117792 Summary: ICE in tsubst_template_args Product: gcc Version: 15.0 URL: https://bugs.linaro.org/show_bug.cgi?id=6058 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: clyon at gcc dot gnu.org Target Milestone: --- As described in https://bugs.linaro.org/show_bug.cgi?id=6058, this short code fragment: ================================== template <const char *fmt, unsigned int fmt_len, typename... Args> static void printf_impl(const char *, Args... args) {} struct Wrapper { template <typename... Args> static void make(Args &&... args) { static const char fmt[] = ""; printf_impl<fmt, 2>(""); } }; int main() { Wrapper::make(); return 0; } ================================== causes GCC to crash on trunk, since gcc-12.1 according to godbolt, and compiles OK with gcc-11.4. It crashes for x86_64, aarch64, arm target at least. The backtrace from godbolt: <source>: In instantiation of 'static void Wrapper::make(Args&& ...) [with Args = {}]': <source>:17:18: required from here 17 | Wrapper::make(); | ~~~~~~~~~~~~~^~ <source>:2:13: internal compiler error: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst, at cp/pt.cc:16467 2 | static void printf_impl(const char *, Args... args) | ^~~~~~~~~~~ 0x28cf075 diagnostic_context::diagnostic_impl(rich_location*, diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag (*) [1], diagnostic_t) ???:0 0x28e5d65 internal_error(char const*, ...) ???:0 0x9a4c09 tree_vec_elt_check_failed(int, int, char const*, int, char const*) ???:0 0xcef624 tsubst_template_args(tree_node*, tree_node*, int, tree_node*) ???:0 0xcd07ad instantiate_decl(tree_node*, bool, bool) ???:0 0xd0ba1b instantiate_pending_templates(int) ???:0 0xb9d23b c_parse_final_cleanups() ???:0 0xe048c8 c_common_parse_file() ???:0