https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117054
Bug ID: 117054
Summary: ICE on variable template initialized to generic lambda
containing constexpr-if containing instantiation of
template with a NTTP defaulted to a lambda
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: eczbek.void at gmail dot com
Target Milestone: ---
This causes an ICE: https://godbolt.org/z/Ybv4qcsGb
```
template<auto = [] {}>
constexpr bool a = true;
template<typename>
auto foo = [](auto) {
if constexpr (a<>) {}
};
int main() {
foo<int>;
}
```
Using built-in specs.
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End of search list.
Compiler executable checksum: faa0e52a30b61670ea00a9530c696e5b
<source>: In instantiation of 'auto foo<int>':
<source>:10:2: required from here
10 | foo<int>;
| ^~~~~~~~
<source>:6:9: internal compiler error: in extract_locals_r, at cp/pt.cc:13479
6 | if constexpr (a<>) {}
| ^~
0x28530e5 diagnostic_context::diagnostic_impl(rich_location*,
diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag
(*) [1], diagnostic_t)
???:0
0x2866ac5 internal_error(char const*, ...)
???:0
0xa8a5ec fancy_abort(char const*, int, char const*)
???:0
0x175eefc walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
???:0
0x175f112 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
???:0
0xcb447f build_extra_args(tree_node*, tree_node*, int)
???:0
0xcc7cad tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*)
???:0
0xcbf4fd instantiate_decl(tree_node*, bool, bool)
???:0
0xb897a3 maybe_instantiate_decl(tree_node*)
???:0
0xb8b417 mark_used(tree_node*, int)
???:0
0xd2552b finish_id_expression(tree_node*, tree_node*, tree_node*, cp_id_kind*,
bool, bool, bool*, bool, bool, bool, bool, char const**, unsigned int)
???:0
0xc97b3a c_parse_file()
???:0
0xdef6f9 c_common_parse_file()
???:0
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Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Preprocessed source stored into /tmp/cc92XJpz.out file, please attach this to
your bugreport.
Compiler returned: 1
