Viewing file:  Wstringop-overflow-34.c (5.99 KB) -rw-r--r--
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/* PR middle-end/95353 - spurious -Wstringop-overflow writing to a trailing
array plus offset
{ dg-do compile }
{ dg-options "-O2 -Wall" } */
typedef __SIZE_TYPE__ size_t;
struct S0 { char n, a[0]; };
void s0_nowarn_cstidx (struct S0 *p)
{
char *q = p->a;
q[1] = __LINE__;
q[9] = __LINE__;
}
void s0_nowarn_cstoff_cstidx (struct S0 *p)
{
char *q = p->a + 1;
q[1] = __LINE__;
q[9] = __LINE__;
}
void s0_nowarn_varoff_cstdix (struct S0 *p, int i)
{
char *q = p->a + i;
q[1] = __LINE__; // { dg-bogus "\\\[-Wstringop-overflow" }
q[9] = __LINE__; // { dg-bogus "\\\[-Wstringop-overflow" }
}
void s0_nowarn_cstoff_varidx (struct S0 *p, int i)
{
char *q = p->a + 1;
q[i] = __LINE__;
}
void s0_nowarn_varoff_varidx (struct S0 *p, int i, int j)
{
char *q = p->a + i;
q[j] = __LINE__; // { dg-bogus "\\\[-Wstringop-overflow" }
}
/* Accesses past the end of a trailing array with one element is
discouraged but still reluctantly not diagnosed. This should
change. */
struct S1 { char n, a[1]; };
void s1_nowarn_cstidx (struct S1 *p)
{
char *q = p->a;
q[1] = __LINE__;
q[9] = __LINE__;
}
void s1_nowarn_cstoff_cstidx (struct S1 *p)
{
char *q = p->a + 1;
q[1] = __LINE__;
q[9] = __LINE__;
}
void s1_nowarn_varoff_cstdix (struct S1 *p, int i)
{
char *q = p->a + i;
q[1] = __LINE__; // { dg-bogus "\\\[-Wstringop-overflow" }
q[9] = __LINE__; // { dg-bogus "\\\[-Wstringop-overflow" }
}
void s1_nowarn_cstoff_varidx (struct S1 *p, int i)
{
char *q = p->a + 1;
q[i] = __LINE__;
}
void s1_nowarn_varoff_varidx (struct S1 *p, int i, int j)
{
char *q = p->a + i;
q[j] = __LINE__;
}
/* Accesses past the end of a trailing array with more than one
element should be diagnosed but aren't yet because the MEM_REF
makes the out-of-bounds accesses indistinguishable from valid
ones to subsequent elements of the array pointed by P. */
struct S2 { char n, a[2]; };
void s2_warn_cstidx (struct S2 *p)
{
char *q = p->a;
/* The following invalid store is represented as
MEM[(char *)p_1(D) + 3B] = __LINE__;
which is indistinguishable from the valid
q = &p[1].n; q[0] = __LINE__;
*/
q[2] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
void s2_warn_cstoff_cstidx (struct S2 *p)
{
char *q = p->a + 1;
q[1] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
void s2_warn_varoff_cstdix (struct S2 *p, int i)
{
char *q = p->a + i;
q[2] = __LINE__; // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
}
void s2_warn_cstoff_varidx (struct S2 *p, int i)
{
char *q = p->a + 1;
q[i] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
void s2_warn_varoff_varidx (struct S2 *p, int i, int j)
{
char *q = p->a + i;
q[j] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
/* Verify that none of these triggers a bogus warning (not tested
elsewhere but triggered during bootstrap). */
void s2_nowarn_varidx_int (struct S2 *p, int i)
{
extern struct S2 s2;
extern struct S2 s2a[];
s2.a[i - 1] = __LINE__;
s2.a[i] = __LINE__;
s2.a[i + 1] = __LINE__;
s2a[i].a[i - 1] = __LINE__;
s2a[i].a[i] = __LINE__;
s2a[i].a[i + 1] = __LINE__;
p[i].a[i - 1] = __LINE__;
p[i].a[i] = __LINE__;
p[i].a[i + 1] = __LINE__;
char *q = p->a;
q[i - 1] = __LINE__;
q[i] = __LINE__;
q[i + 1] = __LINE__;
}
/* Same as above but with a size_t index in range [1, SIZE_MAX]. */
void* s2_nowarn_varidx_size (struct S2 *p, size_t i, size_t j)
{
extern struct S2 s2;
extern struct S2 s2a[];
struct S2 *ps2 = __builtin_malloc (3 * sizeof *ps2);
s2.a[i - 1] = __LINE__;
s2.a[i] = __LINE__;
s2.a[i + 1] = __LINE__;
s2a[i].a[i - 1] = __LINE__;
s2a[i].a[i] = __LINE__;
s2a[i].a[i + 1] = __LINE__;
p[i].a[i - 1] = __LINE__;
p[i].a[i] = __LINE__;
p[i].a[i + 1] = __LINE__;
ps2->a[i - 1] = __LINE__;
ps2->a[i] = __LINE__;
ps2->a[i + 1] = __LINE__;
char *q = p->a;
q[i - 1] = __LINE__;
q[i] = __LINE__;
q[i + 1] = __LINE__;
if (j == 0)
return ps2;
s2.a[j - 1] = __LINE__;
s2.a[j] = __LINE__;
s2.a[j + 1] = __LINE__;
s2a[j].a[j - 1] = __LINE__;
s2a[j].a[j] = __LINE__;
s2a[j].a[j + 1] = __LINE__;
p[j].a[j - 1] = __LINE__;
p[j].a[j] = __LINE__;
p[j].a[j + 1] = __LINE__;
ps2->a[j - 1] = __LINE__;
ps2->a[j] = __LINE__;
ps2->a[j + 1] = __LINE__;
q = p->a;
q[j - 1] = __LINE__;
q[j] = __LINE__;
q[j + 1] = __LINE__;
return ps2;
}
/* Verify that accesses to an interior zero-length array are diagnosed. */
struct Si0 { char c, a[0], d; };
void si0_warn_cstidx (struct Si0 *p)
{
// These are indistinguishable from valid accesses to p->d:
// MEM[(char *)p_1(D) + 1B] = 0;
char *q = p->a;
q[1] = __LINE__; // { dg-warning "writing 1 byte into a region of size 0" "pr?????" { xfail *-*-* } }
q[9] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
void si0_warn_cstoff_cstidx (struct Si0 *p)
{
// Like those above, these too are indistinguishable from valid accesses
// to p->d.
char *q = p->a + 1;
q[1] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
q[9] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
void si0_warn_varoff_cstdix (struct Si0 *p, int i)
{
char *q = p->a + i;
q[1] = __LINE__; // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
q[9] = __LINE__; // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
}
void si0_warn_cstoff_varidx (struct Si0 *p, int i)
{
char *q = p->a + 1;
q[i] = __LINE__; // { dg-warning "\\\[-Wstringop-overflow" "pr?????" { xfail *-*-* } }
}
void si0_warn_varoff_varidx (struct Si0 *p, int i, int j)
{
char *q = p->a + i;
q[j] = __LINE__; // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" }
}
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