https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117107
Bug ID: 117107
Summary: internal compiler error: Segmentation fault at
lookup_decomp_type(tree_node*)
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: yihan4845 at gmail dot com
Target Milestone: ---
Compiler Explorer: https://godbolt.org/z/dMP9rdf1M
The following program:
```cpp
template <typename, typename>
constexpr bool is_same = false;
template <typename T>
constexpr bool is_same<T, T> = true;
struct tuple {
template <unsigned long I>
void check_tuple_like() {
tuple t;
auto [v, r] = t;
(void)[v, r] {
decltype(v);
};
}
int a = 0;
int &b = a;
};
```
will trigger segmentation fault for gcc trunk.
The stack dump:
```
0x285c505 diagnostic_context::diagnostic_impl(rich_location*,
diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag
(*) [1], diagnostic_t)
???:0
0x28702e5 internal_error(char const*, ...)
???:0
0xb796f5 lookup_decomp_type(tree_node*)
???:0
0xd1e956 finish_decltype_type(tree_node*, bool, int)
???:0
0xc989da c_parse_file()
???:0
0xdf0599 c_common_parse_file()
???:0
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1
```
