Package: libstdc++-14-dev
Version: 14-20240330-1
Severity: normal
Tags: upstream
Dear Maintainer,
* What led up to the situation?
Importing multiple module-compiled system headers using compilation commands
like
g++ --std=c++23 -Wall -fmodules-ts -x c++-system-header vector
and importing those compiled system headers in a program results in an
internal compiler error when 'import <memory>;' is also used.
* What exactly did you do (or not do) that was effective (or
ineffective)?
First the system headers where compiled using the abovementioned commad.
Then the compiled headers (like vector.gcm) were made available via the
program's gcm.cache subdirectory. The program was compiled using
g++ --std=c++23 -Wall -fmodules-ts -freport-bug -c main.cc
The following program compiled OK:
import <string>;
import <vector>;
//import <memory>;
int main()
{
std::vector<int> vect;
}
But when activating 'import <memory>;' compilation fails and the compiler
reports an internal compiler error.
There's no internal compiler error when only vector and memory are imported
(i.e., only using these import statements):
import <vector>;
import <memory>;
but once 'import <string>;' is also specified the internal compiler error
results.
* What was the outcome of this action?
The compiler, when importing string, vector, and memory, produced the
following output (shown between the ======== lines):
===================================================================
In file included from /usr/include/c++/14/format:49,
from /usr/include/c++/14/ostream:43,
from /usr/include/c++/14/bits/unique_ptr.h:43,
from /usr/include/c++/14/memory:78,
of module /usr/include/c++/14/memory, imported at main.cc:7:
/usr/include/c++/14/span: In instantiation of ‘constexpr std::span<_Type,
18446744073709551615> std::span<_Type, _Extent>::subspan(size_type, size_type)
const [with _Type = wchar_t; long unsigned int _Extent = 18446744073709551615;
size_type = long unsigned int]’:
/usr/include/c++/14/format:2671:31: required from ‘constexpr std::span<_Type,
18446744073709551615> std::__format::_Sink<_CharT>::_M_unused() const [with
_CharT = wchar_t]’
2671 | { return _M_span.subspan(_M_next - _M_span.begin()); }
| ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/format:2735:13: required from
‘std::__format::_Sink<_CharT>::_Reservation
std::__format::_Sink<_CharT>::_M_reserve(std::size_t) [with _CharT = wchar_t;
std::size_t = long unsigned int]’
2735 | if (__n <= _M_unused().size())
| ^~~~~~~~~
/usr/include/c++/14/format:2733:7: required from here
2733 | _M_reserve(size_t __n)
| ^~~~~~~~~~
/usr/include/c++/14/span:439:49: internal compiler error: in insert, at
cp/module.cc:4929
439 | return {this->data() + __offset, __count};
| ^
0x76cb4f trees_in::insert(tree_node*)
../../src/gcc/cp/module.cc:4929
0x76cb4f trees_in::insert(tree_node*)
../../src/gcc/cp/module.cc:4927
0x100da8a trees_in::add_indirect_tpl_parms(tree_node*)
../../src/gcc/cp/module.cc:7353
0x100dbf0 trees_in::add_indirects(tree_node*)
../../src/gcc/cp/module.cc:7419
0x102c17f trees_in::tree_node(bool)
../../src/gcc/cp/module.cc:9964
0x1032d99 module_state::read_cluster(unsigned int)
../../src/gcc/cp/module.cc:14977
0x103364d module_state::load_section(unsigned int, binding_slot*)
../../src/gcc/cp/module.cc:18477
0x103370e module_state::lazy_load(unsigned int, binding_slot*)
../../src/gcc/cp/module.cc:19161
0x1036afc lazy_load_pendings(tree_node*)
../../src/gcc/cp/module.cc:19262
0x10f8887 lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
../../src/gcc/cp/pt.cc:10030
0x10f9fdf tsubst_aggr_type_1
../../src/gcc/cp/pt.cc:14171
0x10fb182 tsubst(tree_node*, tree_node*, int, tree_node*)
../../src/gcc/cp/pt.cc:16783
0x10fa5eb tsubst(tree_node*, tree_node*, int, tree_node*)
../../src/gcc/cp/pt.cc:16231
0x10ffe94 tsubst_template_args(tree_node*, tree_node*, int, tree_node*)
../../src/gcc/cp/pt.cc:13891
0xf330c2 normalize_concept_check
../../src/gcc/cp/constraint.cc:761
0xf330c2 normalize_atom
../../src/gcc/cp/constraint.cc:816
0xf330c2 normalize_expression
../../src/gcc/cp/constraint.cc:886
0xf33800 normalize_logical_operation
../../src/gcc/cp/constraint.cc:693
0xf337a5 normalize_logical_operation
../../src/gcc/cp/constraint.cc:692
0xf33709 normalize_concept_check
../../src/gcc/cp/constraint.cc:795
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-14/README.Bugs> for instructions.
===================================================================
* What outcome did you expect instead?
I expected that the program would also successfully compile when <vector>,
<string> and <memory> were imported.
As a more extensive test I also compiled the program importing <limits>,
<deque>, <string>, and <vector>: this variant also compiles OK.
Interestingly when importing all these system headers, including <string> the
internal compiler error was again observed. It looks like the combination of
importing <string> and <memory> causes the error.
But on the other hand: the following program, merely defining a std::string
and importing <string> and <memory>, successfully compiles:
import <string>;
import <memory>;
int main()
{
std::string str;
}
-- System Information:
Debian Release: trixie/sid
APT prefers testing
APT policy: (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 6.7.12-amd64 (SMP w/4 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages libstdc++-14-dev depends on:
ii gcc-14-base 14-20240330-1
ii libc6-dev 2.38-13
ii libgcc-14-dev 14-20240330-1
ii libstdc++6 14-20240330-1
libstdc++-14-dev recommends no packages.
Versions of packages libstdc++-14-dev suggests:
pn libstdc++-14-doc <none>
-- no debconf information
