https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121893
Bug ID: 121893
Summary: [Modules] ICE when using modules + ranges. regression
in gcc 16.0
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: shyeyian at petalmail dot com
Target Milestone: ---
===== main.cpp =====
import std;
auto func(const std::string& str) {
return str | std::views::reverse;
}
int main ( ) { }
===== version =====
g++ (GCC) 16.0.0 20250910 (experimental)
git = 06628704c611b1a7f788e64b306338c653ad074d
===== command =====
[anonymous@matebook test-gcc]$ /opt/gcc/bin/g++ -std=c++23 -fmodules -c
/opt/gcc/include/c++/16.0.0/bits/std.cc -o std.o
[anonymous@matebook test-gcc]$ /opt/gcc/bin/g++ -std=c++23 -fmodules main.cpp
-o main
In file included from /opt/gcc/include/c++/16.0.0/compare:43,
from /opt/gcc/include/c++/16.0.0/bits/stl_pair.h:65,
from /opt/gcc/include/c++/16.0.0/bits/stl_algobase.h:64,
from /opt/gcc/include/c++/16.0.0/algorithm:62,
from
/opt/gcc/include/c++/16.0.0/x86_64-pc-linux-gnu/bits/stdc++.h:53,
from /opt/gcc/include/c++/16.0.0/bits/std.cc:30,
of module std, imported at main.cpp:1:
/opt/gcc/include/c++/16.0.0/concepts: In substitution of 'template<class _Tp,
class _Up> requires (__adl_swap<_Tp, _Up>) || (same_as<_Tp, _Up>) &&
(is_lvalue_reference_v<_Tp>) && (move_constructible<typename
std::remove_reference<_Tp>::type>) && (assignable_from<_Tp, typename
std::remove_reference<_Tp>::type>) constexpr void
std::ranges::__swap::_Swap::operator()(_Tp&&, _Up&&) const [with _Tp =
std::ranges::ref_view<const std::__cxx11::basic_string<char> >&; _Up =
std::ranges::ref_view<const std::__cxx11::basic_string<char> >&]':
required by substitution of 'template<class _Vp> requires (view<_Vp>) &&
(bidirectional_range<_Vp>) class std::ranges::reverse_view [with _Vp =
std::ranges::ref_view<const std::__cxx11::basic_string<char> >]'
/opt/gcc/include/c++/16.0.0/concepts:259:52:
259 | = requires(_Tp& __a, _Tp& __b) { ranges::swap(__a, __b); };
| ~~~~~~~~~~~~^~~~~~~~~~
required by substitution of 'template<class _Range>
std::ranges::reverse_view(_Range&&) -> reverse_view<views::all_t<_Range> >
[with _Range = const std::__cxx11::basic_string<char>&]'
/opt/gcc/include/c++/16.0.0/ranges:4103:5:
4103 | reverse_view(_Range&&) -> reverse_view<views::all_t<_Range>>;
| ^~~~~~~~~~~~
required by substitution of 'template<class _Range> requires
(viewable_range<_Range>) && ((__is_reverse_view<typename
std::remove_cvref<_Tp>::type>) || (__is_reversible_subrange<typename
std::remove_cvref<_Tp>::type>) || (__can_reverse_view<_Range>)) constexpr auto
std::ranges::views::_Reverse::operator()(_Range&&) const [with _Range = const
std::__cxx11::basic_string<char>&]'
/opt/gcc/include/c++/16.0.0/ranges:4130:17:
4130 | = requires { reverse_view{std::declval<_Range>()}; };
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
required by substitution of 'template<class _Self, class _Range> requires
(__is_range_adaptor_closure<_Self>) && (__adaptor_invocable<_Self, _Range>)
constexpr auto std::ranges::views::__adaptor::operator|(_Range&&, _Self&&)
[with _Self = const std::ranges::views::_Reverse&; _Range = const
std::__cxx11::basic_string<char>&]'
/opt/gcc/include/c++/16.0.0/ranges:934:44:
934 | = requires { std::declval<_Adaptor>()(declval<_Args>()...); };
| ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
required from here
main.cpp:4:30:
4 | return str | std::views::reverse;
| ^~~~~~~
/opt/gcc/include/c++/16.0.0/concepts:200:17: internal compiler error: tree
check: expected function_decl, have using_decl in add_candidates, at
cp/call.cc:6761
200 | swap(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u));
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0x28e1a37 internal_error(char const*, ...)
../../git/gcc/diagnostic-global-context.cc:786
0x9a3707 tree_check_failed(tree_node const*, char const*, int, char const*,
...)
../../git/gcc/tree.cc:9188
0x77c22c tree_check(tree_node*, char const*, int, char const*, tree_code)
../../git/gcc/tree.h:3733
0x77c22c add_candidates
../../git/gcc/cp/call.cc:6761
0xabc280 add_candidates
../../git/gcc/cp/call.cc:5157
0xabc280 perform_overload_resolution
../../git/gcc/cp/call.cc:5174
0xac25f1 build_new_function_call(tree_node*, vec<tree_node*, va_gc,
vl_embed>**, int)
../../git/gcc/cp/call.cc:5275
0xd5a64c finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
../../git/gcc/cp/semantics.cc:3534
0xd0201e tsubst_expr(tree_node*, tree_node*, int, tree_node*)
../../git/gcc/cp/pt.cc:21960
0xb149c8 tsubst_valid_expression_requirement
../../git/gcc/cp/constraint.cc:1346
0xb1c5ef tsubst_simple_requirement
../../git/gcc/cp/constraint.cc:1383
0xb1c5ef tsubst_requirement
../../git/gcc/cp/constraint.cc:1598
0xb1c5ef tsubst_requires_expr
../../git/gcc/cp/constraint.cc:1738
0xb1ccda tsubst_requires_expr(tree_node*, tree_node*, int, tree_node*)
../../git/gcc/cp/constraint.cc:1762
0xcffb2f tsubst_expr(tree_node*, tree_node*, int, tree_node*)
../../git/gcc/cp/pt.cc:22739
0xb1db7a satisfy_atom
../../git/gcc/cp/constraint.cc:2478
0xb1db7a satisfy_constraint_r
../../git/gcc/cp/constraint.cc:2544
0xb1d2b1 satisfy_disjunction
../../git/gcc/cp/constraint.cc:2297
0xb1d2b1 satisfy_constraint_r
../../git/gcc/cp/constraint.cc:2542
0xb1e1d1 satisfy_normalized_constraints
../../git/gcc/cp/constraint.cc:2569
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.
===== additional =====
Above ICE in g++ 16.0, but works in g++ 15.2.
