blob: 489a0cd717c3c521024becfffaa03ff60da336c7 [file] [log] [blame]
/* PR c/102103 - missing warning comparing array address to null
{ dg-do compile }
{ dg-options "-Wall" } */
typedef __INTPTR_TYPE__ intptr_t;
typedef __INTPTR_TYPE__ uintptr_t;
extern char *ax[], *a2[][2];
void T (int);
void test_ax_plus_eq_0 (int i)
{
// Verify that casts to intptr_t suppress the warning.
T ((intptr_t)(ax + 0) == 0);
T ((uintptr_t)(ax + 1) == 0);
T (ax + 0 == 0); // { dg-warning "-Waddress" }
T (&ax[0] == 0); // { dg-warning "-Waddress" }
T (ax - 1 == 0); // { dg-warning "-Waddress" }
T (0 == &ax[-1]); // { dg-warning "-Waddress" }
T ((void *)(&ax[0] + 2) == 0); // { dg-warning "-Waddress" }
T (&ax[0] + 2 == 0); // { dg-warning "-Waddress" }
T (ax + 3 == 0); // { dg-warning "-Waddress" }
T (0 == &ax[-4]); // { dg-warning "-Waddress" }
T (ax - i == 0); // { dg-warning "-Waddress" }
T (&ax[i] == 0); // { dg-warning "-Waddress" }
T (0 == &ax[1] + i); // { dg-warning "-Waddress" }
}
void test_a2_plus_eq_0 (int i)
{
// Verify that casts to intptr_t suppress the warning.
T ((intptr_t)(a2 + 0) == 0);
T ((uintptr_t)(a2 + 1) == 0);
T (a2 + 0 == 0); // { dg-warning "-Waddress" }
// Verify that a cast to another pointer type doesn't suppress it.
T ((void*)(a2 + 0) == 0); // { dg-warning "-Waddress" }
T ((char*)a2 + 1 == 0); // { dg-warning "-Waddress" }
T (&a2[0] == 0); // { dg-warning "-Waddress" }
T (a2 - 1 == 0); // { dg-warning "-Waddress" }
T (0 == &a2[-1]); // { dg-warning "-Waddress" }
T (a2 + 2 == 0); // { dg-warning "-Waddress" }
T (0 == &a2[-2]); // { dg-warning "-Waddress" }
T (a2 - i == 0); // { dg-warning "-Waddress" }
T (&a2[i] == 0); // { dg-warning "-Waddress" }
}
// Exercise a pointer.
void test_p_plus_eq_0 (int *p, int i)
{
/* P + 0 and equivalently &P[0] are invalid for a null P but they're
folded to p before the warning has a chance to trigger. */
T (p + 0 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (&p[0] == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (p - 1 == 0); // { dg-warning "-Waddress" }
T (0 == &p[-1]); // { dg-warning "-Waddress" }
T (p + 2 == 0); // { dg-warning "-Waddress" }
T (0 == &p[-2]); // { dg-warning "-Waddress" }
T (p - i == 0); // { dg-warning "-Waddress" }
T (&p[i] == 0); // { dg-warning "-Waddress" }
}
// Exercise pointer to array.
void test_pa_plus_eq_0 (int (*p)[], int (*p2)[][2], int i)
{
// The array pointer may be null.
T (*p == 0);
/* &**P is equivalent to *P and might be the result od macro expansion.
Verify it doesn't cause a warning. */
T (&**p == 0);
/* *P + 0 is invalid but folded to *P before the warning has a chance
to trigger. */
T (*p + 0 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (&(*p)[0] == 0); // { dg-warning "-Waddress" }
T (*p - 1 == 0); // { dg-warning "-Waddress" }
T (0 == &(*p)[-1]); // { dg-warning "-Waddress" }
T (*p + 2 == 0); // { dg-warning "-Waddress" }
T (0 == &(*p)[-2]); // { dg-warning "-Waddress" }
T (*p - i == 0); // { dg-warning "-Waddress" }
T (&(*p)[i] == 0); // { dg-warning "-Waddress" }
/* Similar to the above but for a pointer to a two-dimensional array,
referring to the higher-level element (i.e., an array itself). */
T (*p2 == 0);
T (**p2 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (&**p2 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (&***p2 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (&**p2 == 0);
T (*p2 + 0 == 0); // { dg-warning "-Waddress" "pr102555" { xfail *-*-* } }
T (&(*p2)[0] == 0); // { dg-warning "-Waddress" }
T (&(*p2)[0][1] == 0); // { dg-warning "-Waddress" }
T (*p2 - 1 == 0); // { dg-warning "-Waddress" }
T (0 == &(*p2)[-1]); // { dg-warning "-Waddress" }
T (0 == &(*p2)[1][2]); // { dg-warning "-Waddress" }
T (*p2 + 2 == 0); // { dg-warning "-Waddress" }
T (0 == &(*p2)[-2]); // { dg-warning "-Waddress" }
T (*p2 - i == 0); // { dg-warning "-Waddress" }
T (&(*p2)[i] == 0); // { dg-warning "-Waddress" }
}