https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125851
Bug ID: 125851
Summary: Many C++ test failures with -std=c++29 (ICE in
get_cxx_dialect_name, at cp/name-lookup.cc:7543)
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code, testsuite-fail
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Target Milestone: ---
```
$ g++ gcc/testsuite/g++.dg/warn/Winterference-2.C -std=c++29 -fmodules
gcc/testsuite/g++.dg/warn/Winterference-2.C:12:18: warning: use of
‘std::hardware_destructive_interference_size’ [-Winterference-size]
12 | alignas(std::hardware_destructive_interference_size) int x; // {
dg-warning Winterference-size }
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
gcc/testsuite/g++.dg/warn/Winterference-2.C:12:18: note: its value can vary
between compiler versions or with different ‘-mtune’ or ‘-mcpu’ flags
gcc/testsuite/g++.dg/warn/Winterference-2.C:12:18: note: if this use is part of
a public ABI, change it to instead use a constant variable you define
gcc/testsuite/g++.dg/warn/Winterference-2.C:12:18: note: the default value for
the current CPU tuning is 64 bytes
gcc/testsuite/g++.dg/warn/Winterference-2.C:12:18: note: you can stabilize this
value with ‘--param hardware_destructive_interference_size=64’, or disable this
warning with ‘-Wno-interference-size’
gcc/testsuite/g++.dg/warn/Winterference-2.C:14:1: internal compiler error: in
get_cxx_dialect_name, at cp/name-lookup.cc:7543
14 | }
| ^
0x561d9715097a internal_error(char const*, ...)
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/diagnostic-global-context.cc:787
0x561d97150b1d fancy_abort(char const*, int, char const*)
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/diagnostics/context.cc:1813
0x561d966ed1bf get_cxx_dialect_name(cxx_dialect)
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/cp/name-lookup.cc:7543
0x561d966ed2ee module_state_config::get_dialect()
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/cp/module.cc:17259
0x561d95489c03 module_state_config::module_state_config()
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/cp/module.cc:17228
0x561d95489c03 module_processing_cookie::module_processing_cookie(char*, char*,
int, int)
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/cp/module.cc:23858
0x561d95489c03 finish_module_processing(cpp_reader*)
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/cp/module.cc:23925
0x561d9743c927 c_parse_final_cleanups()
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/cp/decl2.cc:6134
0x561d98041028 c_common_parse_file()
/usr/src/debug/sys-devel/gcc-17.0.9999/gcc-17.0.9999/gcc/c-family/c-opts.cc:1455
/usr/libexec/gcc/x86_64-pc-linux-gnu/17/cc1plus -quiet -D_GNU_SOURCE
gcc/testsuite/g++.dg/warn/Winterference-2.C -quiet -dumpdir a- -dumpbase
Winterference-2.C -dumpbase-ext .C -mtune=generic -march=x86-64
-mtls-dialect=gnu2 -std=c++29 -fmodules -foffload-options=-l_GCC_stdc++
-foffload-options=-l_GCC_m -foffload-options=-fno-stack-protector
-fcf-protection -foffload-options=-fcf-protection=none -o /tmp/ccF8jm5U.s
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://bugs.gentoo.org/> for instructions.
```
```
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/17/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-17.0.9999/work/gcc-17.0.9999/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/17
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/17/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/17
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/17/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/17/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/17/include/g++-v17
--disable-silent-rules --disable-dependency-tracking
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/17/python
--enable-libphobos --enable-objc-gc
--enable-languages=c,c++,d,objc,obj-c++,fortran,ada,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 17.0.9999 p, commit
8cd95414f0988009e664760bda1f7d9feb6bf01a' --with-gcc-major-version-only
--enable-libstdcxx-time --enable-lto --disable-libstdcxx-pch
--enable-linker-build-id --enable-libada --enable-shared --enable-threads=posix
--enable-__cxa_atexit --enable-clocale=gnu --with-tls=gnu2 --enable-multilib
--with-multilib-list=m32,mx32,m64 --disable-fixed-point --with-abi=m64
--enable-targets=all --enable-offload-defaulted
--enable-offload-targets=nvptx-none --enable-libgomp --disable-libssp
--enable-cet --disable-systemtap --enable-valgrind-annotations
--enable-valgrind-interop --disable-vtable-verify --disable-libvtv --with-zstd
--without-isl --enable-default-pie --enable-host-pie --enable-host-bind-now
--enable-default-ssp --disable-fixincludes
--with-gxx-libcxx-include-dir=/usr/include/c++/v1
--with-build-config='bootstrap-O3 bootstrap-lto bootstrap-cet'
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 17.0.0 20260616 (experimental)
9e6ce124e2fcf08e395196590b2952e410227473 (Gentoo 17.0.9999 p, commit
8cd95414f0988009e664760bda1f7d9feb6bf01a)
```
