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
59
60
61
62
63
64
65
66
67
68
69
70
|
/* PR c++/66555 */
/* { dg-do compile } */
/* { dg-options "-Wtautological-compare" } */
#define X 5
#define Y 5
#define A a
enum { U };
void
fn1 (int a, int *p)
{
if (a > a); /* { dg-warning "self-comparison always evaluates to false" } */
if (a < a); /* { dg-warning "self-comparison always evaluates to false" } */
if (a >= a); /* { dg-warning "self-comparison always evaluates to true" } */
if (a <= a); /* { dg-warning "self-comparison always evaluates to true" } */
if (a == a); /* { dg-warning "self-comparison always evaluates to true" } */
if (a != a); /* { dg-warning "self-comparison always evaluates to false" } */
if (A == A); /* { dg-warning "self-comparison always evaluates to true" } */
if ((unsigned) a != (unsigned) a);
if ((a + 1) <= (a + 1)); /* { dg-warning "self-comparison always evaluates to true" } */
if (1 ? a == a : 0); /* { dg-warning "self-comparison always evaluates to true" } */
if (fn1 == fn1); /* { dg-warning "self-comparison always evaluates to true" } */
if (*p == *p); /* { dg-warning "self-comparison always evaluates to true" } */
volatile int v = 5;
if (v == v);
if (v != v);
}
void
fn2 (int a)
{
if (sizeof (int) >= 4);
if (sizeof (char) != 1);
if (sizeof (long) != sizeof (long long));
if (0 < sizeof (short));
if (5 != 5);
if (X > 5);
if (X == X);
if (3 + 4 == 6 + 1);
if ((unsigned) a != (unsigned long) a);
if (U == U);
if (U > 0);
}
void
fn3 (int i, int j)
{
static int a[16];
static int b[8][8];
if (a[5] == a[5]);
if (a[X] != a[Y]);
if (a[X] != a[X]);
if (a[i] == a[i]); /* { dg-warning "self-comparison always evaluates to true" } */
if (b[5][5] == b[5][5]);
if (b[X][Y] >= b[Y][X]);
if (b[X][X] == b[Y][Y]);
if (b[i][j] != b[i][j]); /* { dg-warning "self-comparison always evaluates to false" } */
if (b[i][Y] < b[i][X]);
if (b[X][j] < b[X][j]);
if ((a[i] + 4) == (4 + a[i])); /* { dg-warning "self-comparison always evaluates to true" } */
}
int
fn4 (int x, int y)
{
return x > x ? 1 : 0; /* { dg-warning "self-comparison always evaluates to false" } */
}
|
