http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60336
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|va_start corrupts 6-th |empty struct value is
|argument in case of empty |passed differently in C and
|type used before the format |C++
|string |
--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Andrew Pinski from comment #3)
> (In reply to H.J. Lu from comment #2)
> > Should g++ put pass the empty struct on stack?
>
> It is a target bug if it is passing on the stack. Note in C++, the size of
> the struct is 1 while in C, the size is 0.
Can someone try this on non-x86 targets?
[hjl@gnu-6 pr60336]$ cat x.ii
struct dummy { };
struct foo
{
int i1;
int i2;
int i3;
int i4;
int i5;
};
extern "C" void fun(struct dummy, struct foo);
int main()
{
struct dummy d;
struct foo f = { -1, -2, -3, -4, -5 };
fun(d, f);
return 0;
}
[hjl@gnu-6 pr60336]$ cat fun.i
struct dummy { };
struct foo
{
int i1;
int i2;
int i3;
int i4;
int i5;
};
void fun(struct dummy d, struct foo f)
{
if (f.i1 != -1)
__builtin_abort();
}
[hjl@gnu-6 pr60336]$ gcc -c fun.i
[hjl@gnu-6 pr60336]$ gcc -c x.ii
[hjl@gnu-6 pr60336]$ g++ fun.o x.o
[hjl@gnu-6 pr60336]$ ./a.out
Aborted
[hjl@gnu-6 pr60336]$
Is this test valid? BTW, clang works fine on x86.
