https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123567
Bug ID: 123567
Summary: [16 Regression] ICE in instantiate_decl, at
cp/pt.cc:28272
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: jirehguo at tju dot edu.cn
Target Milestone: ---
Compiler Explorer: https://godbolt.org/z/3c4Wroebn
The following c++ code crash gcc trunk.
But 13,14,15 with checking is fine.
Code:
```cpp
template <auto =
[] {
class LocalClass {
void test();
};
LocalClass lc;
lc.test();
}>
constexpr bool flag = true;
template <typename> void f() { if constexpr (flag<>) }
int main() { f<int>(); }
```
Stack dump:
```
<source>: In function 'void f()':
<source>:10:54: error: expected primary-expression before '}' token
[-Wtemplate-body]
10 | template <typename> void f() { if constexpr (flag<>) }
| ^
<source>: In instantiation of 'void<lambda()>::LocalClass::test()':
required from 'void f() [with <template-parameter-1-1> = int]'
<source>:7:24:
7 | lc.test();
| ~~~~~~~^~
required from here
<source>:11:20:
11 | int main() { f<int>(); }
| ~~~~~~^~
<source>:7:24: internal compiler error: in instantiate_decl, at cp/pt.cc:28272
7 | lc.test();
| ~~~~~~~^~
0x2926688 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
???:0
0x291b44b internal_error(char const*, ...)
???:0
0xb16d54 fancy_abort(char const*, int, char const*)
???:0
0xc2e0cf mark_used(tree_node*, int)
???:0
0xd81555 tsubst_lambda_expr(tree_node*, tree_node*, int, tree_node*)
???:0
0xd9bce9 tsubst_template_args(tree_node*, tree_node*, int, tree_node*)
???:0
0xdb965d instantiate_decl(tree_node*, bool, bool)
???:0
0xdc306a instantiate_pending_templates(int)
???:0
0xc32a28 c_parse_final_cleanups()
???:0
0xec8f18 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
```
