https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65816
Casey Carter <Casey at Carter dot net> changed:
What |Removed |Added
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CC| |Casey at Carter dot net
--- Comment #3 from Casey Carter <Casey at Carter dot net> ---
I ran across an almost identical case, but involving a base subobject which
isn't properly zero-initialized rather than the member subobject case in
comment 1:
void* operator new(decltype(sizeof(int)), void* ptr) {
return ptr;
}
struct item { int data; };
struct collector : item {
collector() = default;
collector(int) {}
};
struct tuple : collector {
tuple() : collector{} {}
};
int main() {
alignas(tuple) unsigned char space[sizeof(tuple)];
for (auto& c : space) c = 0xff;
auto ptr = ::new(&space) tuple;
int& i = static_cast<item&>(*ptr).data;
if (i != 0) __builtin_abort();
}
Default-initialization of `tuple` invokes its constructor, which
value-initializes its `collector` base subobject, which should zero-initialize
`collector`'s `item` base subobject.
