https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119328
Bug ID: 119328
Summary: ICE on generic lambda with defaulted parameter in
requires clause
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: ---
https://godbolt.org/z/jn16q96jv
```cpp
int x = 0;
int main() {
[](auto x) requires requires { []<int = 0>(int = x) {}(); } {}(0);
}
```
```
Using built-in specs.
COLLECT_GCC=/opt/compiler-explorer/gcc-snapshot/bin/g++
Target: x86_64-linux-gnu
Configured with: ../gcc-trunk-20250317/configure
--prefix=/opt/compiler-explorer/gcc-build/staging
--enable-libstdcxx-backtrace=yes --build=x86_64-linux-gnu
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--enable-ld=yes --enable-gold=yes --enable-libstdcxx-debug
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Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.1 20250317 (experimental)
(Compiler-Explorer-Build-gcc-a3ead22b42de8ddeeb869df2fa9cbdae7af5204d-binutils-2.42)
COLLECT_GCC_OPTIONS='-fdiagnostics-color=always' '-g' '-o' '/app/output.s'
'-masm=intel' '-fno-verbose-asm' '-S' '-std=c++20' '-v' '-freport-bug'
'-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' '/app/'
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GNU C++20
(Compiler-Explorer-Build-gcc-a3ead22b42de8ddeeb869df2fa9cbdae7af5204d-binutils-2.42)
version 15.0.1 20250317 (experimental) (x86_64-linux-gnu)
compiled by GNU C version 11.4.0, GMP version 6.2.1, MPFR version
4.1.0, MPC version 1.2.1, isl version isl-0.24-GMP
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
ignoring nonexistent directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../x86_64-linux-gnu/include"
ignoring duplicate directory
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ignoring duplicate directory
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ignoring duplicate directory
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ignoring duplicate directory
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ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring duplicate directory
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ignoring duplicate directory
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ignoring nonexistent directory
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#include "..." search starts here:
#include <...> search starts here:
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/x86_64-linux-gnu
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/backward
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/include
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/include-fixed/x86_64-linux-gnu
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/include-fixed
/usr/local/include
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../include
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
Compiler executable checksum: 7eb22631251594d4e511620990a18033
<source>: In substitution of 'template<class auto:1> main()::<lambda(auto:1)>
[with auto:1 = int]':
<source>:4:64: required from here
4 | [](auto x) requires requires { []<int = 0>(int = x) {}(); }
{}(0);
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
<source>:4:63: internal compiler error: in tsubst_expr, at cp/pt.cc:21910
4 | [](auto x) requires requires { []<int = 0>(int = x) {}(); }
{}(0);
| ~~~~~~~~~~~~~~~~~~~~~~~^~
0x2913db5 diagnostic_context::diagnostic_impl(rich_location*,
diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag
(*) [1], diagnostic_t)
???:0
0x292add6 internal_error(char const*, ...)
???:0
0xaccc40 fancy_abort(char const*, int, char const*)
???:0
0xd33b14 tsubst_default_argument(tree_node*, int, tree_node*, tree_node*, int)
???:0
0xaec972 convert_default_arg(tree_node*, tree_node*, tree_node*, int, int)
???:0
0xb087d3 build_op_call(tree_node*, vec<tree_node*, va_gc, vl_embed>**, int)
???:0
0xd6df75 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
???:0
0xb547d6 tsubst_requires_expr(tree_node*, tree_node*, int, tree_node*)
???:0
0xb56248 constraints_satisfied_p(tree_node*, tree_node*)
???:0
0xd4d1c3 fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node*
const*, unsigned int, tree_node*, unification_kind_t, int, conversion**, bool,
bool)
???:0
0xb081b2 build_op_call(tree_node*, vec<tree_node*, va_gc, vl_embed>**, int)
???:0
0xd6df75 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
???:0
0xcee07b c_parse_file()
???:0
0xe4f519 c_common_parse_file()
???:0
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Preprocessed source stored into /tmp/cch1P5Fe.out file, please attach this to
your bugreport.
Compiler returned: 1
```
