https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100588
Bug ID: 100588
Summary: Destroying delete shouldn't be called if constructor
throws
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: richardpku at gmail dot com
Target Milestone: ---
Consider this program:
#include <cstdio>
#include <new>
class A {
public:
A() { throw 42; }
~A() { puts("A::~A"); }
void operator delete(void* p) {
puts("regular delete invoked");
::operator delete(p);
}
void operator delete(A* p, std::destroying_delete_t) {
puts("destroying delete invoked");
p->~A();
::operator delete(p);
}
};
int main() {
try {
new A;
} catch (int) {
}
}
Output compiled with GCC:
destroying delete invoked
A::~A
Output compiled with Clang:
regular delete invoked
I believe clang has the correct behavior.
A destroying delete function is expected to invoke the destructor explicitly.
As a result, the current GCC implementation would indirectly invoke the
destructor on an instance that wasn't successfully constructed, which obviously
isn't the intended behavior.
It is even worse if class A has a base class, in which case the destructor of
the base class is called twice if an exception is thrown in A's constructor.
