https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106125
Bug ID: 106125
Summary: [c++2a] Segmentation fault in constexpr initialization
of static variable
Product: gcc
Version: 10.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mameluc at gmail dot com
Target Milestone: ---
Created attachment 53217
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53217&action=edit
Preprocessed file (compressed)
The following code triggers a segfault. Tested with g++ 10.3.0, -O0 to -O3
/* starts here */
template<typename ... T>
struct DataStructure
{
};
template<size_t N>
struct StringLiteral
{
constexpr StringLiteral (const char (&str)[N])
{
std::copy_n(str, N, value);
}
constexpr auto operator<=>(const StringLiteral&) const = default;
constexpr bool operator==(const StringLiteral&) const = default;
static constexpr auto len = N;
char value[N];
};
////////////////////////////////////////////////////////////////////////
template <StringLiteral Name, typename T>
struct Item
{
constexpr static auto item_name = Name;
T data;
};
////////////////////////////////////////////////////////////////////////
template <StringLiteral Target, typename... Rest>
struct Test
{
static constexpr auto eq = false;
};
template <StringLiteral Target, typename First, typename... Rest>
struct Test<Target, First, Rest...>
{
static constexpr auto eq = (Target == First::item_name) || Test<Target,
Rest...>::eq;
};
////////////////////////////////////////////////////////////////////////
template<typename T, typename ... Rest>
struct DataStructure<T, Rest ...>
{
constexpr DataStructure()
: first()
, rest()
{
// this line!
static_assert(!Test<T::item_name, Rest...>::eq, "repeated id in data
structure");
}
T first;
DataStructure<Rest ... > rest;
};
DataStructure<
Item<"Ident::ZUM", int>,
Item<"Ident::FOO", float>,
Item<"Ident::BAR", float>
> data;
/* ends here */
g++-10 -save-temps -std=c++2a test_segfault.cpp
test_segfault.cpp: In constructor ‘constexpr DataStructure<T, Rest
...>::DataStructure()’:
test_segfault.cpp:58:50: internal compiler error: Segmentation fault
58 | static_assert(!Test<T::item_name, Rest...>::eq, "repeated id in
data structure");
| ^
0x7f3d44ebe08f ???
/build/glibc-SzIz7B/glibc-2.31/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0
0x7f3d44e9f082 __libc_start_main
../csu/libc-start.c:308
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-10/README.Bugs> for instructions.
make: *** [Makefile:2: all] Error 1
//////////////////////////////////////////////////////////////////////////////////////
Compiler info:
Using built-in specs.
COLLECT_GCC=g++-10
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
10.3.0-1ubuntu1~20.04' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-10
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib
--enable-libphobos-checking=release --with-target-system-zlib=auto
--enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib
--with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-10-S4I5Pr/gcc-10-10.3.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-10-S4I5Pr/gcc-10-10.3.0/debian/tmp-gcn/usr,hsa
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-mutex
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.3.0 (Ubuntu 10.3.0-1ubuntu1~20.04)
