https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77316
--- Comment #3 from Roland Dreier <rbd at debian dot org> ---
I managed to simplify the test case a bit by hand. The significant thing seems
to be "decltype(nullptr)" - if I change that to, say, void*, then I don't get
the spurious symbol.
$ cat b.cpp
template <typename _Alloc> class vector {
public:
vector();
vector(const _Alloc &) {}
void operator=(vector) { vector a(get_allocator()); }
_Alloc get_allocator();
};
template <typename>
struct allocator_affinity {};
typedef vector<allocator_affinity<decltype(nullptr)>> addr_list_t;
addr_list_t ad;
void startt() {
ad = addr_list_t();
}
$ g++-5 -std=c++11 -o b.o -c b.cpp
$ objdump -C -t b.o
b.o: file format elf64-x86-64
SYMBOL TABLE:
0000000000000000 l df *ABS* 0000000000000000 b.cpp
0000000000000000 l d .text 0000000000000000 .text
0000000000000000 l d .data 0000000000000000 .data
0000000000000000 l d .bss 0000000000000000 .bss
0000000000000000 l d .text._ZN6vectorI18allocator_affinityIDnEEaSES2_
0000000000000000 .text._ZN6vectorI18allocator_affinityIDnEEaSES2_
0000000000000000 l d .text._ZN6vectorI18allocator_affinityIDnEEC2ERKS1_
0000000000000000 .text._ZN6vectorI18allocator_affinityIDnEEC2ERKS1_
000000000000002f l F .text 000000000000002a
__static_initialization_and_destruction_0(int, int)
0000000000000059 l F .text 0000000000000015 _GLOBAL__sub_I_ad
0000000000000000 l d .init_array 0000000000000000 .init_array
0000000000000000 l d .note.GNU-stack 0000000000000000
.note.GNU-stack
0000000000000000 l d .eh_frame 0000000000000000 .eh_frame
0000000000000000 l .group 0000000000000000
vector<allocator_affinity<decltype(nullptr)>
>::vector(allocator_affinity<decltype(nullptr)> const&)
0000000000000000 l d .comment 0000000000000000 .comment
0000000000000000 l d .group 0000000000000000 .group
0000000000000000 l d .group 0000000000000000 .group
0000000000000000 g O .bss 0000000000000001 ad
0000000000000000 g F .text 000000000000002f startt()
0000000000000000 *UND* 0000000000000000
vector<allocator_affinity<decltype(nullptr)> >::vector()
0000000000000000 w F .text._ZN6vectorI18allocator_affinityIDnEEaSES2_
000000000000002e vector<allocator_affinity<decltype(nullptr)>
>::operator=(vector<allocator_affinity<decltype(nullptr)> >)
0000000000000000 *UND* 0000000000000000
vector<allocator_affinity<decltype(nullptr)> >::get_allocator()
0000000000000000 w F .text._ZN6vectorI18allocator_affinityIDnEEC2ERKS1_
000000000000000f vector<allocator_affinity<decltype(nullptr)>
>::vector(allocator_affinity<decltype(nullptr)> const&)
0000000000000000 w F .text._ZN6vectorI18allocator_affinityIDnEEaSES2_
000000000000002e _ZN6vectorI18allocator_affinityIDnEEaSES3_
0000000000000000 w F .text._ZN6vectorI18allocator_affinityIDnEEC2ERKS1_
000000000000000f vector<allocator_affinity<decltype(nullptr)>
>::vector(allocator_affinity<decltype(nullptr)> const&)
0000000000000000 w F .text._ZN6vectorI18allocator_affinityIDnEEC2ERKS1_
000000000000000f vector<allocator_affinity<decltype(nullptr)>
>::vector(vector<allocator_affinity<decltype(nullptr)> > const&)
0000000000000000 w F .text._ZN6vectorI18allocator_affinityIDnEEC2ERKS1_
000000000000000f vector<allocator_affinity<decltype(nullptr)>
>::vector(vector<allocator_affinity<decltype(nullptr)> > const&)
