https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101040
Bug ID: 101040
Summary: [11 Regression] Internal compiler error: in
get_or_insert_ctor_field, at cp/constexpr.c:3571
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: git at foonathan dot net
Target Milestone: ---
Minimal repro: https://godbolt.org/z/n71dhjPox
```
// This class has to be empty.
struct empty
{};
// This class has to be empty.
struct single
{
// This member has to be no_unique_address.
[[no_unique_address]] empty obj;
};
// This class has to be empty and derived from single.
struct derived : single
{
// This constructor has to be constexpr and take a forwarding reference.
template <typename Arg>
constexpr derived(Arg&& arg) : single{arg}
{}
};
auto obj = derived{empty{}};
```
Fails on GCC 11.1 and trunk:
```
source>:21:27: in 'constexpr' expansion of 'derived(empty())'
<source>:21:27: internal compiler error: in get_or_insert_ctor_field, at
cp/constexpr.c:3571
21 | auto obj = derived{empty{}};
| ^
0x1d322a9 internal_error(char const*, ...)
???:0
0x71fc09 fancy_abort(char const*, int, char const*)
???:0
0xa58de0 store_init_value(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, int)
???:0
0x818a14 cp_finish_decl(tree_node*, tree_node*, bool, tree_node*, int)
???:0
0x94812d c_parse_file()
???:0
0xacb002 c_common_parse_file()
???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1
```
Works with GCC 10.3.
