https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119346
Bug ID: 119346
Summary: ICE: in tsubst_pack_expansion, at cp/pt.cc:13899
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/hdTaKb7Mv
```cpp
int main() {
[]<int = 0> {
return (..., []<int... x> { x; });
}();
}
```
```
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
--host=x86_64-linux-gnu --target=x86_64-linux-gnu --disable-bootstrap
--enable-multiarch --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --enable-clocale=gnu
--enable-languages=c,c++,fortran,ada,objc,obj-c++,go,d,rust,m2,cobol
--enable-ld=yes --enable-gold=yes --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-linker-build-id --enable-lto
--enable-plugins --enable-threads=posix
--with-pkgversion=Compiler-Explorer-Build-gcc-a3ead22b42de8ddeeb869df2fa9cbdae7af5204d-binutils-2.42
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/'
/opt/compiler-explorer/gcc-trunk-20250317/bin/../libexec/gcc/x86_64-linux-gnu/15.0.1/cc1plus
-quiet -v -imultiarch x86_64-linux-gnu -iprefix
/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/x86_64-linux-gnu/15.0.1/
-D_GNU_SOURCE <source> -quiet -dumpdir /app/ -dumpbase output.cpp -dumpbase-ext
.cpp -masm=intel -mtune=generic -march=x86-64 -g -std=c++20 -version
-fdiagnostics-color=always -fno-verbose-asm -freport-bug -o /app/output.s
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
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1"
ignoring duplicate directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/x86_64-linux-gnu"
ignoring duplicate directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../include/c++/15.0.1/backward"
ignoring duplicate directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/include"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring duplicate directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/include-fixed/x86_64-linux-gnu"
ignoring duplicate directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/include-fixed"
ignoring nonexistent directory
"/opt/compiler-explorer/gcc-trunk-20250317/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/15.0.1/../../../../x86_64-linux-gnu/include"
#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 instantiation of 'main()::<lambda()> [with int <anonymous> = 0]':
<source>:4:3: required from here
2 | []<int = 0> {
| ~~~~~~~~~~~~~
3 | return (..., []<int... x> { x; });
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4 | }();
| ~^~
<source>:3:28: internal compiler error: in tsubst_pack_expansion, at
cp/pt.cc:13899
3 | return (..., []<int... x> { x; });
| ~~~~^~~~~~~~~~~~~~~~~~~~~~
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
0xd188fd instantiate_decl(tree_node*, bool, bool)
???:0
0xbd3673 maybe_instantiate_decl(tree_node*)
???:0
0xbd5327 mark_used(tree_node*, 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
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/ccpI8VPc.out file, please attach this to
your bugreport.
Compiler returned: 1
```
