https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120949
Bug ID: 120949
Summary: [16 regression] <algorithm> rejected with clang-20.1.7
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Target Milestone: ---
Created attachment 61797
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61797&action=edit
readable.cpp
This is using Holger's example from
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120358#c22.
```
$ clang++ -DQT_NO_DEBUG -std=c++20 -Wall -Wextra -ggdb3 -O3 $(pkg-config --libs
--cflags Qt6Core) readable.cpp && ./a.out
In file included from readable.cpp:3:
In file included from /usr/include/qt6/QtCore/QStringTokenizer:1:
In file included from /usr/include/qt6/QtCore/qstringtokenizer.h:6:
In file included from /usr/include/qt6/QtCore/qnamespace.h:12:
In file included from /usr/include/qt6/QtCore/qglobal.h:49:
In file included from /usr/include/qt6/QtCore/qflags.h:10:
In file included from
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/algorithm:62:
In file included from
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/bits/stl_algobase.h:67:
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/bits/stl_iterator.h:1344:42:
error: an attribute list cannot appear here
1344 | __attribute__((__always_inline__)) _GLIBCXX_NODISCARD
| ^~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/x86_64-pc-linux-gnu/bits/c++config.h:173:29:
note: expanded from macro '_GLIBCXX_NODISCARD'
173 | # define _GLIBCXX_NODISCARD [[__nodiscard__]]
| ^~~~~~~~~~~~~~~~~
In file included from readable.cpp:3:
In file included from /usr/include/qt6/QtCore/QStringTokenizer:1:
In file included from /usr/include/qt6/QtCore/qstringtokenizer.h:6:
In file included from /usr/include/qt6/QtCore/qnamespace.h:12:
In file included from /usr/include/qt6/QtCore/qglobal.h:49:
In file included from /usr/include/qt6/QtCore/qflags.h:10:
In file included from
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/algorithm:62:
In file included from
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/bits/stl_algobase.h:67:
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/bits/stl_iterator.h:1352:42:
error: an attribute list cannot appear here
1352 | __attribute__((__always_inline__)) _GLIBCXX_NODISCARD
| ^~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16/x86_64-pc-linux-gnu/bits/c++config.h:173:29:
note: expanded from macro '_GLIBCXX_NODISCARD'
173 | # define _GLIBCXX_NODISCARD [[__nodiscard__]]
| ^~~~~~~~~~~~~~~~~
2 errors generated.
```
---
```
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/16/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-16.0.9999/work/gcc-16.0.9999/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/16
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/16/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/16
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/16/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/16/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/16/include/g++-v16
--disable-silent-rules --disable-dependency-tracking
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/16/python
--enable-libphobos --enable-objc-gc
--enable-languages=c,c++,d,objc,obj-c++,fortran,ada,cobol,m2,rust
--enable-obsolete --enable-secureplt --disable-werror --with-system-zlib
--enable-nls --without-included-gettext --disable-libunwind-exceptions
--enable-checking=yes,extra,rtl --with-bugurl=https://bugs.gentoo.org/
--with-pkgversion='Gentoo Hardened 16.0.9999 p, commit
9fdf5a30ded9c691d9fcdb787e72f8dd0f111f8a' --with-gcc-major-version-only
--enable-libstdcxx-time --enable-lto --disable-libstdcxx-pch --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
--enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point
--enable-targets=all --enable-offload-defaulted
--enable-offload-targets=nvptx-none --enable-libgomp --disable-libssp
--enable-libada --disable-cet --disable-systemtap --enable-valgrind-annotations
--disable-vtable-verify --disable-libvtv --with-zstd --with-isl
--disable-isl-version-check --enable-default-pie --enable-host-pie
--enable-host-bind-now --enable-default-ssp --disable-fixincludes
--with-gxx-libcxx-include-dir=/usr/include/c++/v1 --enable-linker-build-id
--with-build-config='bootstrap-O3 bootstrap-lto'
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.0 20250704 (experimental)
d6ed12ed5ebac8e50da9defea6af832039782cbf (Gentoo Hardened 16.0.9999 p, commit
9fdf5a30ded9c691d9fcdb787e72f8dd0f111f8a)
```
