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/* PR middle-end/103215 - bogus -Wstringop-overflow with two pointers with
different offsets each
Test for accesses into distinct arrays through pointers with different
offsets each.
If/when -Wstringop-overflow is enhanced to issue "maybe" kinds of
warnings some of the accesses here will trigger those and will need
updating.
{ dg-do compile }
{ dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
#define NOIPA __attribute__ ((noipa))
void sink (int[1]);
#define A(p, off) sink (p + off)
extern int a4[4], a8[8];
NOIPA void a4_p1_a8_p3 (int i)
{
int *a4_p1 = a4 + 1;
int *a8_p3 = a8 + 3;
int *q = i ? a4_p1 : a8_p3;
A (q, -4); // { dg-warning "-Wstringop-overflow" }
/* Because -3 is a valid offset into a8 but not a4, q must point
to the former and so subscripts between -3 and +4 refer to its
elements. */
A (q, -3); A (q, -2); A (q, -1); A (q, 0);
A (q, 1); A (q, 2); A (q, 3); A (q, 4);
A (q, 5); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
/* Both of the following are definitely out of bounds but the first isn't
diagnosed because the code conservatively merges the offsets into A4
and A8. */
A (q, 7); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void a4_p1_a8_p5 (int i)
{
int *a4_p1 = a4 + 1;
int *a8_p5 = a8 + 5;
int *q = i ? a4_p1 : a8_p5;
A (q, -6); // { dg-warning "-Wstringop-overflow" }
/* Similarly to the above, because -5 is a valid offset into a8 but
not a4, q must point to the former and so subscripts between -5
and +2 refer to its elements. */
A (q, -5); A (q, -4); A (q, -3); A (q, -2);
A (q, -1); A (q, 0); A (q, 1); A (q, 2);
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void a4_p1_a8_p7 (int i)
{
int *a4_p1 = a4 + 1;
int *a8_p7 = a8 + 7;
int *q = i ? a4_p1 : a8_p7;
A (q, -8); // { dg-warning "-Wstringop-overflow" }
A (q, -7); A (q, -6); A (q, -5); A (q, -4);
A (q, -3); A (q, -2); A (q, -1); A (q, 0);
/* Since -7 is valid, q must point to a8 and the last valid subscript
must be 0. */
A (q, 1); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 2); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void mp_1_a4_p1_a8_p7 (int i, int j)
{
int *a4_p1 = a4 + 1;
int *a8_p7 = a8 + 7;
int *p = i ? a4_p1 : a8_p7;
int *q = j ? p + 1 : p - 1;
A (q, -9); // { dg-warning "-Wstringop-overflow" }
/* q points either to a8 + [6, 8] or a4 + [0, 2]. */
A (q, -8); A (q, -7); A (q, -6); A (q, -5);
A (q, -4); A (q, -3); A (q, -2); A (q, -1);
/* Since all the above are valid, q must point to a8 + 8. But as
mentioned above, the warning for each subscript is independent
of prior subscripts into the same object so the access below
aren't diagnosed. */
A (q, 0); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 1); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 2); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 4); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 8); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void mp1_a4_p1_a8_p5 (int i, int j)
{
int *a4_p1 = a4 + 1;
int *a8_p5 = a8 + 5;
int *p = i ? a4_p1 : a8_p5;
int *q = j ? p + 1 : p - 1;
// q is assumed to point to a8 + 6
A (q, -7); // { dg-warning "-Wstringop-overflow" }
A (q, -6); A (q, -5); A (q, -4); A (q, -3);
A (q, -2); A (q, -1); A (q, 0); A (q, 1);
/* Even though the above accesses rule it out, q is now assumed
to point to either a4 + [0, 2] or a8 + [4, 5]. */
A (q, 2);
/* q is now assumed to point tp a4. Given that, only the first store
is valid. */
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 4); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 5); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 6); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 8); // { dg-warning "-Wstringop-overflow" }
}
NOIPA void mp1_a4_p1_a8_p4 (int i, int j)
{
int *a4_p1 = a4 + 1;
int *a8_p4 = a8 + 4;
int *p = i ? a4_p1 : a8_p4;
int *q = j ? p + 1 : p - 1;
// q is assumed to point to a8 + 5
A (q, -6); // { dg-warning "-Wstringop-overflow" }
A (q, -5);
A (q, -4);
A (q, -3);
A (q, -2);
A (q, -1);
A (q, 0);
A (q, 1);
A (q, 2);
/* Even though the above accesses rule it out, q is now assumed
to point tp a4. Given that, only the first store is valid. */
A (q, 3); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 4); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 5); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 6); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 7); // { dg-warning "-Wstringop-overflow" "pr??????" { xfail *-*-* } }
A (q, 8); // { dg-warning "-Wstringop-overflow" }
}
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