------- Comment #4 from spark at gcc dot gnu dot org 2008-01-24 18:16 -------
I don't think this can be implemented in the FE,
at least to be really effective.
The more common cases are not really "empty" destructor.
E.g. there's inlining involved:
class Foo
{
public:
virtual ~Foo();
};
Foo::~Foo()
{
}
class Bar : public Foo
{
public:
virtual ~Bar();
};
Bar::~Bar()
{
}
where Foo::~Foo() has to be inlined before we can determine
~Bar() is really empty.
But "emptiness" isn't really how we want to decide eliminating those
but rather the dependence on the vtable itself. e.g.:
extern "C" int printf(const char* s);
class Foo
{
public:
virtual ~Foo();
};
Foo::~Foo()
{
printf("good bye foo\n");
}
class Bar : public Foo
{
public:
virtual ~Bar();
};
Bar::~Bar()
{
printf("good bye bar\n");
}
In this case, there's no need for vtable update inside the destructor
(which is more common).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34949
