1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
// { dg-do run }
#include <algorithm>
#include <testsuite_hooks.h>
// PR libstdc++/108846 std::copy, std::copy_n and std::copy_backward
// on potentially overlapping subobjects
struct B {
B(int i, short j) : i(i), j(j) {}
int i;
short j;
};
struct D : B {
D(int i, short j, short x) : B(i, j), x(x) {}
short x; // Stored in tail padding of B
};
void
test_pr108846()
{
D ddst(1, 2, 3);
D dsrc(4, 5, 6);
B *dst = &ddst;
B *src = &dsrc;
// If this is optimized to memmove it will overwrite tail padding.
std::copy_backward(src, src+1, dst+1);
VERIFY(ddst.x == 3);
}
struct B2 {
B2(int i, short j) : i(i), j(j) {}
B2& operator=(B2& b) { i = b.i; j = b.j; return *this; }
int i;
short j;
};
struct D2 : B2 {
D2(int i, short j, short x) : B2(i, j), x(x) {}
short x; // Stored in tail padding of B2
};
void
test_non_const_copy_assign()
{
D2 ddst(1, 2, 3);
D2 dsrc(4, 5, 6);
B2 *dst = &ddst;
B2 *src = &dsrc;
// Ensure the not-taken trivial copy path works for this type.
std::copy_backward(src, src+1, dst+1);
VERIFY(ddst.x == 3);
}
int main()
{
test_pr108846();
test_non_const_copy_assign();
}
|
