https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85386
Bug ID: 85386
Summary: ICE when applying noexcept operator to default
constructor
Product: gcc
Version: 7.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: andysem at mail dot ru
Target Milestone: ---
Created attachment 43923
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43923&action=edit
A testcase that shows the problem.
The following testcase causes ICE:
template< typename T >
class allocator
{
};
template< typename T >
struct is_ebo_possible
{
static constexpr bool value = true;
};
template< typename Char, typename Allocator, bool = is_ebo_possible< Allocator
>::value >
struct ebo
{
typedef Allocator allocator_type;
allocator_type m_allocator;
// ebo() noexcept(std::is_nothrow_default_constructible< allocator_type
>::value) = default;
ebo() noexcept(noexcept(allocator_type())) = default;
};
template< typename Char, typename Allocator >
struct ebo< Char, Allocator, true > :
public Allocator
{
typedef Allocator allocator_type;
ebo() noexcept(noexcept(allocator_type())) = default;
};
int main()
{
ebo< char, allocator< char > > m;
return 0;
}
$ g++ -o noexcept_def_ctor_test noexcept_def_ctor_test.cpp
noexcept_def_ctor_test.cpp: In instantiation of ‘ebo<Char, Allocator,
true>::ebo() [with Char = char; Allocator = allocator<char>]’:
noexcept_def_ctor_test.cpp:24:8: required from ‘struct ebo<char,
allocator<char> >’
noexcept_def_ctor_test.cpp:34:36: required from here
noexcept_def_ctor_test.cpp:20:29: internal compiler error: Segmentation fault
ebo() noexcept(noexcept(allocator_type())) = default;
^~~~~~~~~~~~~~~~
This happens with gcc 7.2 but not 6.4. If I replace the noexcept operator with
the is_nothrow_default_constructible trait as in the commented line, ICE
doesn't happen.
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
7.2.0-8ubuntu3.2' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-7
--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 --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --with-target-system-zlib --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 --without-cuda-driver
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 7.2.0 (Ubuntu 7.2.0-8ubuntu3.2)
