https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116807
Bug ID: 116807
Summary: About c++ 20 module,chrono header file
Product: gcc
Version: 14.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: wxy_it at 163 dot com
Target Milestone: ---
Created attachment 59173
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=59173&action=edit
the code for reproduction
When both module A and module B include the <chrono> header in the global
module, and module A imports module B, it will cause a bug.
I tried modifying the "auto" at line 2631 of
/usr/local/include/c++/14.2.0/format to the actual type
"_Sink<_CharT>::_Reservation", which can fix the bug.
The attached file contains the code for reproduction. I used CMake for the
build, and the runtime environment is the gcc:14.2.0-bookworm Docker image,
with the image ID 5b2fe0643fc9.
[main] Building folder: /root/workspace/module_test/build
[build] Starting build
[proc] Executing command: /root/cmake-3.30.3-linux-x86_64/bin/cmake --build
/root/workspace/module_test/build --config Debug --target all --
[build] [1/7 14% :: 0.039] Scanning /root/workspace/module_test/a.cpp for CXX
dependencies
[build] [2/7 28% :: 0.041] Generating CXX dyndep file
CMakeFiles/demo.dir/CXX.dd
[build] [3/4 75% :: 0.347] Building CXX object CMakeFiles/demo.dir/a.cpp.o
[build] FAILED: CMakeFiles/demo.dir/a.cpp.o
[build] /usr/local/bin/g++ -g -std=gnu++20 -MD -MT
CMakeFiles/demo.dir/a.cpp.o -MF CMakeFiles/demo.dir/a.cpp.o.d -fmodules-ts
-fmodule-mapper=CMakeFiles/demo.dir/a.cpp.o.modmap -MD -fdeps-format=p1689r5 -x
c++ -o CMakeFiles/demo.dir/a.cpp.o -c /root/workspace/module_test/a.cpp
[build] In file included from
/usr/local/include/c++/14.2.0/bits/chrono_io.h:39,
[build] from /usr/local/include/c++/14.2.0/chrono:3360,
[build] from /root/workspace/module_test/a.ixx:3,
[build] of module ModuleA, imported at /root/workspace/module_test/a.cpp:6:
[build] /usr/local/include/c++/14.2.0/bits/basic_string.tcc: In substitution of
'template<class _Tp> constexpr typename std::remove_reference<_Tp>::type&&
std::move(_Tp&&) [with _Tp = std::__cxx11::to_string(int)::<lambda(char*,
std::size_t)>&]':
[build] /usr/local/include/c++/14.2.0/bits/basic_string.tcc:602:27: required
from 'constexpr void std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::__resize_and_overwrite(size_type, _Operation) [with _Operation =
std::__cxx11::to_string(int)::<lambda(char*, std::size_t)>; _CharT = char;
_Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type =
long unsigned int]'
[build] 602 | auto __r = std::move(__op)(__p + 0, __n + 0);
[build] | ~~~~~~~~~^~~~~~
[build] /usr/local/include/c++/14.2.0/bits/basic_string.h:4249:33: required
from here
[build] 4249 | __str.__resize_and_overwrite(__neg + __len, [=](char* __p,
size_t __n) {
[build] |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[build] 4250 | __p[0] = '-';
[build] | ~~~~~~~~~~~~~
[build] 4251 | __detail::__to_chars_10_impl(__p + (int)__neg, __len,
__uval);
[build] |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[build] 4252 | return __n;
[build] | ~~~~~~~~~~~
[build] 4253 | });
[build] | ~~
[build] /usr/local/include/c++/14.2.0/format:2632:7: error: conflicting global
module declaration 'auto
std::__format::_Sink_iter@ModuleB<_CharT>::_M_reserve(std::size_t) const [with
_CharT = char; std::size_t = long unsigned int]'
[build] 2632 | _M_reserve(size_t __n) const
[build] | ^~~~~~~~~~
[build] In file included from
/usr/local/include/c++/14.2.0/bits/chrono_io.h:39,
[build] from /usr/local/include/c++/14.2.0/chrono:3360,
[build] from /root/workspace/module_test/b.ixx:3,
[build] of module ModuleB, imported at /root/workspace/module_test/a.ixx:6,
[build] of module ModuleA, imported at /root/workspace/module_test/a.cpp:6:
[build] /usr/local/include/c++/14.2.0/format:2632:7: note: existing declaration
'auto std::__format::_Sink_iter@ModuleB<_CharT>::_M_reserve(std::size_t) const
[with _CharT = char; std::size_t = long unsigned int]'
[build] 2632 | _M_reserve(size_t __n) const
[build] | ^~~~~~~~~~
[build] In file included from /usr/local/include/c++/14.2.0/string:55,
[build] from
/usr/local/include/c++/14.2.0/bits/locale_classes.h:40,
[build] from /usr/local/include/c++/14.2.0/bits/ios_base.h:41,
[build] from /usr/local/include/c++/14.2.0/ios:44,
[build] from /usr/local/include/c++/14.2.0/ostream:40,
[build] from /usr/local/include/c++/14.2.0/iostream:41,
[build] from /root/workspace/module_test/a.cpp:3:
[build] /usr/local/include/c++/14.2.0/bits/basic_string.tcc:602:27: note:
during load of pendings for 'std::move'
[build] 602 | auto __r = std::move(__op)(__p + 0, __n + 0);
[build] | ~~~~~~~~~^~~~~~
[build] ninja: build stopped: subcommand failed.
[proc] The command: /root/cmake-3.30.3-linux-x86_64/bin/cmake --build
/root/workspace/module_test/build --config Debug --target all -- exited with
code: 1
