On Tue, 11 Dec 2012, Jakub Jelinek wrote:
> Hi!
>
> As discussed on IRC, fixing this issue is probably 4.9 material, we have
> some plans, but not for 4.8. What GCC generates is actually not incorrect,
> given __builtin_object_size (x, 1) being a high bound, it is just larger than
> strictly required, but I hope it won't trigger very much on real-world code,
> where it could mean less strict -D_FORTIFY_SOURCE=2 protection.
> The following patch xfails the problematic testcase and instead adds a new
> testcase which tests the same things, but doesn't test interaction of
> different __builtin_object_size calls (for different fields) from the same
> pointer. Tested on x86_64-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2012-12-11 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/54570
> * gcc.dg/builtin-object-size-8.c: Xfail.
> * gcc.dg/builtin-object-size-13.c: New test.
>
> --- gcc/testsuite/gcc.dg/builtin-object-size-8.c.jj 2009-07-20
> 20:41:51.000000000 +0200
> +++ gcc/testsuite/gcc.dg/builtin-object-size-8.c 2012-12-11
> 15:13:59.646748335 +0100
> @@ -1,4 +1,4 @@
> -/* { dg-do run } */
> +/* { dg-do run { xfail *-*-* } } */
> /* { dg-options "-O2" } */
>
> typedef __SIZE_TYPE__ size_t;
> --- gcc/testsuite/gcc.dg/builtin-object-size-13.c.jj 2012-12-11
> 15:10:48.046891600 +0100
> +++ gcc/testsuite/gcc.dg/builtin-object-size-13.c 2012-12-11
> 15:10:24.000000000 +0100
> @@ -0,0 +1,351 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2" } */
> +
> +typedef __SIZE_TYPE__ size_t;
> +extern void *malloc (size_t);
> +extern void free (void *);
> +extern void abort (void);
> +
> +union A
> +{
> + int a1;
> + char a2[3];
> +};
> +
> +union B
> +{
> + long long b1;
> + union A b2;
> +};
> +
> +struct C
> +{
> + int c1;
> + union A c2;
> +};
> +
> +struct D
> +{
> + int d1;
> + union B d2;
> +};
> +
> +union E
> +{
> + struct C e1;
> + char e2[3];
> +};
> +
> +union F
> +{
> + int f1;
> + struct D f2;
> +};
> +
> +struct G
> +{
> + union A g1;
> + char g2;
> +};
> +
> +struct H
> +{
> + int h1;
> + union E h2;
> +};
> +
> +#define T(X, S0, S1) \
> + if (__builtin_object_size (X, 0) != (S0)) \
> + abort (); \
> + if (__builtin_object_size (X, 1) != (S1)) \
> + abort (); \
> + if (__builtin_object_size (X, 2) != (S0)) \
> + abort (); \
> + if (__builtin_object_size (X, 3) != (S1)) \
> + abort ()
> +#define TS(X, S0) T(&X, S0, sizeof (X))
> +#define TA(X, S0, S1) \
> + T(X, S0, S1); T(&X[0], S0, S1); T(&X[1], (S0) - 1, (S1) - 1)
> +#define TF(X, S0) TA(X, S0, S0)
> +
> +int
> +main (void)
> +{
> + size_t s, o, o2;
> +
> + s = sizeof (union A);
> + o = 0;
> + union A *a1 = malloc (s);
> + union A *a2 = malloc (o + 212);
> + TS (a1->a1, s);
> + s = o + 212;
> + TS (a2->a1, s);
> + free (a2);
> + free (a1);
> + s = sizeof (union A);
> + o = 0;
> + a1 = malloc (s);
> + a2 = malloc (o + 212);
> + TF (a1->a2, s);
> + s = o + 212;
> + TF (a2->a2, s);
> + free (a2);
> + free (a1);
> +
> + s = sizeof (union B);
> + o = 0;
> + union B *b1 = malloc (s);
> + union B *b2 = malloc (o + 212);
> + TS (b1->b1, s);
> + s = o + 212;
> + TS (b2->b1, s);
> + free (b2);
> + free (b1);
> + s = sizeof (union B);
> + o = 0;
> + b1 = malloc (s);
> + b2 = malloc (o + 212);
> + TS (b1->b2.a1, s);
> + s = o + 212;
> + TS (b2->b2.a1, s);
> + free (b2);
> + free (b1);
> + s = sizeof (union B);
> + o = 0;
> + b1 = malloc (s);
> + b2 = malloc (o + 212);
> + TF (b1->b2.a2, s);
> + s = o + 212;
> + TF (b2->b2.a2, s);
> + free (b2);
> + free (b1);
> +
> + s = sizeof (struct C);
> + o = __builtin_offsetof (struct C, c2);
> + struct C *c1 = malloc (s);
> + struct C *c2 = malloc (o + 212);
> + TS (c1->c1, s);
> + s = o + 212;
> + TS (c2->c1, s);
> + free (c2);
> + free (c1);
> + s = sizeof (struct C);
> + o = __builtin_offsetof (struct C, c2);
> + c1 = malloc (s);
> + c2 = malloc (o + 212);
> + TS (c1->c2.a1, s - o);
> + s = o + 212;
> + TS (c2->c2.a1, s - o);
> + free (c2);
> + free (c1);
> + s = sizeof (struct C);
> + o = __builtin_offsetof (struct C, c2);
> + c1 = malloc (s);
> + c2 = malloc (o + 212);
> + TF (c1->c2.a2, s - o);
> + s = o + 212;
> + TF (c2->c2.a2, s - o);
> + free (c2);
> + free (c1);
> +
> + s = sizeof (struct D);
> + o = __builtin_offsetof (struct D, d2);
> + struct D *d1 = malloc (s);
> + struct D *d2 = malloc (o + 212);
> + TS (d1->d1, s);
> + s = o + 212;
> + TS (d2->d1, s);
> + free (d2);
> + free (d1);
> + s = sizeof (struct D);
> + o = __builtin_offsetof (struct D, d2);
> + d1 = malloc (s);
> + d2 = malloc (o + 212);
> + TS (d1->d2.b1, s - o);
> + s = o + 212;
> + TS (d2->d2.b1, s - o);
> + free (d2);
> + free (d1);
> + s = sizeof (struct D);
> + o = __builtin_offsetof (struct D, d2);
> + d1 = malloc (s);
> + d2 = malloc (o + 212);
> + TS (d1->d2.b2.a1, s - o);
> + s = o + 212;
> + TS (d2->d2.b2.a1, s - o);
> + free (d2);
> + free (d1);
> + s = sizeof (struct D);
> + o = __builtin_offsetof (struct D, d2);
> + d1 = malloc (s);
> + d2 = malloc (o + 212);
> + TF (d1->d2.b2.a2, s - o);
> + s = o + 212;
> + TF (d2->d2.b2.a2, s - o);
> + free (d2);
> + free (d1);
> +
> + s = sizeof (union E);
> + o = __builtin_offsetof (union E, e1.c2);
> + union E *e1 = malloc (s);
> + union E *e2 = malloc (o + 212);
> + TS (e1->e1.c1, s);
> + s = o + 212;
> + TS (e2->e1.c1, s);
> + free (e2);
> + free (e1);
> + s = sizeof (union E);
> + o = __builtin_offsetof (union E, e1.c2);
> + e1 = malloc (s);
> + e2 = malloc (o + 212);
> + TS (e1->e1.c2.a1, s - o);
> + s = o + 212;
> + TS (e2->e1.c2.a1, s - o);
> + free (e2);
> + free (e1);
> + s = sizeof (union E);
> + o = __builtin_offsetof (union E, e1.c2);
> + e1 = malloc (s);
> + e2 = malloc (o + 212);
> + TF (e1->e1.c2.a2, s - o);
> + s = o + 212;
> + TF (e2->e1.c2.a2, s - o);
> + free (e2);
> + free (e1);
> + s = sizeof (union E);
> + o = __builtin_offsetof (union E, e1.c2);
> + e1 = malloc (s);
> + e2 = malloc (o + 212);
> + TF (e1->e2, s);
> + s = o + 212;
> + TF (e2->e2, s);
> + free (e2);
> + free (e1);
> +
> + s = sizeof (union F);
> + o = __builtin_offsetof (union F, f2.d2);
> + union F *f1 = malloc (s);
> + union F *f2 = malloc (o + 212);
> + TS (f1->f1, s);
> + s = o + 212;
> + TS (f2->f1, s);
> + free (f2);
> + free (f1);
> + s = sizeof (union F);
> + o = __builtin_offsetof (union F, f2.d2);
> + f1 = malloc (s);
> + f2 = malloc (o + 212);
> + TS (f1->f2.d1, s);
> + s = o + 212;
> + TS (f2->f2.d1, s);
> + free (f2);
> + free (f1);
> + s = sizeof (union F);
> + o = __builtin_offsetof (union F, f2.d2);
> + f1 = malloc (s);
> + f2 = malloc (o + 212);
> + TS (f1->f2.d2.b1, s - o);
> + s = o + 212;
> + TS (f2->f2.d2.b1, s - o);
> + free (f2);
> + free (f1);
> + s = sizeof (union F);
> + o = __builtin_offsetof (union F, f2.d2);
> + f1 = malloc (s);
> + f2 = malloc (o + 212);
> + TS (f1->f2.d2.b2.a1, s - o);
> + s = o + 212;
> + TS (f2->f2.d2.b2.a1, s - o);
> + free (f2);
> + free (f1);
> + s = sizeof (union F);
> + o = __builtin_offsetof (union F, f2.d2);
> + f1 = malloc (s);
> + f2 = malloc (o + 212);
> + TF (f1->f2.d2.b2.a2, s - o);
> + s = o + 212;
> + TF (f2->f2.d2.b2.a2, s - o);
> + free (f2);
> + free (f1);
> +
> + s = sizeof (struct G);
> + o = __builtin_offsetof (struct G, g2);
> + struct G *g1 = malloc (s);
> + struct G *g2 = malloc (o + 212);
> + TS (g1->g1.a1, s);
> + s = o + 212;
> + TS (g2->g1.a1, s);
> + free (g2);
> + free (g1);
> + s = sizeof (struct G);
> + o = __builtin_offsetof (struct G, g2);
> + g1 = malloc (s);
> + g2 = malloc (o + 212);
> + TA (g1->g1.a2, s, sizeof (g1->g1.a2));
> + s = o + 212;
> + TA (g2->g1.a2, s, sizeof (g1->g1.a2));
> + free (g2);
> + free (g1);
> + s = sizeof (struct G);
> + o = __builtin_offsetof (struct G, g2);
> + g1 = malloc (s);
> + g2 = malloc (o + 212);
> + TS (g1->g2, s - o);
> + s = o + 212;
> + TS (g2->g2, s - o);
> + free (g2);
> + free (g1);
> +
> + s = sizeof (struct H);
> + o = __builtin_offsetof (struct H, h2);
> + o2 = __builtin_offsetof (struct H, h2.e1.c2);
> + struct H *h1 = malloc (s);
> + struct H *h2 = malloc (o2 + 212);
> + TS (h1->h1, s);
> + s = o2 + 212;
> + TS (h2->h1, s);
> + free (h2);
> + free (h1);
> + s = sizeof (struct H);
> + o = __builtin_offsetof (struct H, h2);
> + o2 = __builtin_offsetof (struct H, h2.e1.c2);
> + h1 = malloc (s);
> + h2 = malloc (o2 + 212);
> + TS (h1->h2.e1.c1, s - o);
> + s = o2 + 212;
> + TS (h2->h2.e1.c1, s - o);
> + free (h2);
> + free (h1);
> + s = sizeof (struct H);
> + o = __builtin_offsetof (struct H, h2);
> + o2 = __builtin_offsetof (struct H, h2.e1.c2);
> + h1 = malloc (s);
> + h2 = malloc (o2 + 212);
> + TS (h1->h2.e1.c2.a1, s - o2);
> + s = o2 + 212;
> + TS (h2->h2.e1.c2.a1, s - o2);
> + free (h2);
> + free (h1);
> + s = sizeof (struct H);
> + o = __builtin_offsetof (struct H, h2);
> + o2 = __builtin_offsetof (struct H, h2.e1.c2);
> + h1 = malloc (s);
> + h2 = malloc (o2 + 212);
> + TA (h1->h2.e1.c2.a2, s - o2, sizeof (h1->h2.e1.c2.a2));
> + s = o2 + 212;
> + TA (h2->h2.e1.c2.a2, s - o2, sizeof (h2->h2.e1.c2.a2));
> + free (h2);
> + free (h1);
> + s = sizeof (struct H);
> + o = __builtin_offsetof (struct H, h2);
> + o2 = __builtin_offsetof (struct H, h2.e1.c2);
> + h1 = malloc (s);
> + h2 = malloc (o2 + 212);
> + TF (h1->h2.e2, s - o);
> + s = o2 + 212;
> + TF (h2->h2.e2, s - o);
> + free (h2);
> + free (h1);
> +
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imend
