gcc/testsuite/gcc.dg/Warray-bounds-92.c

   1 /* PR middle-end/103215 - bogus -Warray-bounds with two pointers with
   2    different offsets each
   3    Test for accesses into distinct arrays through pointers with different
   4    offsets each.
   5
   6    If/when -Warray-bounds is enhanced to issue "maybe" kinds of warnings
   7    some of the accesses here will trigger those and will need updating.
   8
   9    { dg-do compile }
  10    { dg-options "-O2 -Wall -ftrack-macro-expansion=0" } */
  11
  12 #define NOIPA __attribute__ ((noipa))
  13
  14 #define A(p, off) ((p)[off] = __COUNTER__)
  15
  16 extern int a4[4], a8[8];
  17
  18
  19 NOIPA void a4_p1_a8_p3 (int i)
  20 {
  21   int *a4_p1 = a4 + 1;
  22   int *a8_p3 = a8 + 3;
  23   int *q = i ? a4_p1 : a8_p3;
  24   A (q, -4);      // { dg-warning "-Warray-bounds" }
  25   /* Because -3 is a valid offset into a8 but not a4, q must point
  26      to the former and so subscripts between -3 and +4 refer to its
  27      elements.  */
  28   A (q, -3); A (q, -2); A (q, -1); A (q, 0);
  29   A (q,  1); A (q,  2); A (q,  3); A (q, 4);
  30   A (q, 5);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  31   /* Both of the following are definitely out of bounds but the first isn't
  32      diagnosed because the code conservatively merges the offsets into A4
  33      and A8.  */
  34   A (q, 7);       // { dg-warning "-Warray-bounds" }
  35 }
  36
  37
  38 NOIPA void a4_p1_a8_p5 (int i)
  39 {
  40   int *a4_p1 = a4 + 1;
  41   int *a8_p5 = a8 + 5;
  42   int *q = i ? a4_p1 : a8_p5;
  43   A (q, -6);     // { dg-warning "-Warray-bounds" }
  44   /* Similarly to the above, because -5 is a valid offset into a8 but
  45      not a4, q must point to the former and so subscripts between -5
  46      and +2 refer to its elements.  */
  47   A (q, -5); A (q, -4); A (q, -3); A (q, -2);
  48   A (q, -1); A (q,  0); A (q,  1); A (q,  2);
  49   A (q, 3);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  50   A (q, 7);       // { dg-warning "-Warray-bounds" }
  51 }
  52
  53
  54 NOIPA void a4_p1_a8_p7 (int i)
  55 {
  56   int *a4_p1 = a4 + 1;
  57   int *a8_p7 = a8 + 7;
  58   int *q = i ? a4_p1 : a8_p7;
  59   A (q, -8);     // { dg-warning "-Warray-bounds" }
  60   A (q, -7); A (q, -6); A (q, -5); A (q, -4);
  61   A (q, -3); A (q, -2); A (q, -1); A (q,  0);
  62   /* Since -7 is valid, q must point to a8 and the last valid subscript
  63      must be 0.  */
  64   A (q, 1);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  65   A (q, 2);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  66   A (q, 3);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  67   A (q, 7);       // { dg-warning "-Warray-bounds" }
  68 }
  69
  70
  71 NOIPA void mp_1_a4_p1_a8_p7 (int i, int j)
  72 {
  73   int *a4_p1 = a4 + 1;
  74   int *a8_p7 = a8 + 7;
  75   int *p = i ? a4_p1 : a8_p7;
  76   int *q = j ? p + 1 : p - 1;
  77
  78   A (q, -9);      // { dg-warning "-Warray-bounds" }
  79
  80   /* q points either to a8 + [6, 8] or a4 + [0, 2].  */
  81   A (q, -8); A (q, -7); A (q, -6); A (q, -5);
  82   A (q, -4); A (q, -3); A (q, -2); A (q, -1);
  83
  84   /* Since all the above are valid, q must point to a8 + 8. But as
  85      mentioned above, the warning for each subscript is independent
  86      of prior subscripts into the same object so the access below
  87      aren't diagnosed.  */
  88   A (q, 0);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  89   A (q, 1);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  90   A (q, 2);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  91   A (q, 3);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  92   A (q, 4);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
  93   A (q, 8);       // { dg-warning "-Warray-bounds" }
  94 }
  95
  96
  97 NOIPA void mp1_a4_p1_a8_p5 (int i, int j)
  98 {
  99   int *a4_p1 = a4 + 1;
 100   int *a8_p5 = a8 + 5;
 101   int *p = i ? a4_p1 : a8_p5;
 102
 103   int *q = j ? p + 1 : p - 1;
 104
 105   // q is assumed to point to a8 + 6
 106   A (q, -7);      // { dg-warning "-Warray-bounds" }
 107   A (q, -6); A (q, -5); A (q, -4); A (q, -3);
 108   A (q, -2); A (q, -1); A (q,  0); A (q,  1);
 109   /* Even though the above accesses rule it out, q is now assumed
 110      to point to either a4 + [0, 2] or a8 + [4, 5].  */
 111   A (q, 2);
 112   /* q is now assumed to point tp a4.  Given that, only the first store
 113      is valid.  */
 114   A (q, 3);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 115   A (q, 4);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 116   A (q, 5);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 117   A (q, 6);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 118   A (q, 7);       // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 119   A (q, 8);       // { dg-warning "-Warray-bounds" }
 120 }
 121
 122
 123 NOIPA void mp1_a4_p1_a8_p4 (int i, int j)
 124 {
 125   int *a4_p1 = a4 + 1;
 126   int *a8_p4 = a8 + 4;
 127   int *p = i ? a4_p1 : a8_p4;
 128
 129   int *q = j ? p + 1 : p - 1;
 130
 131   // q is assumed to point to a8 + 5
 132   A (q, -6);      // { dg-warning "-Warray-bounds" }
 133   A (q, -5);
 134   A (q, -4);
 135   A (q, -3);
 136   A (q, -2);
 137   A (q, -1);
 138   A (q,  0);
 139   A (q,  1);
 140   A (q,  2);
 141   /* Even though the above accesses rule it out, q is now assumed
 142      to point tp a4.  Given that, only the first store is valid.  */
 143   A (q,  3);      // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 144   A (q,  4);      // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 145   A (q,  5);      // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 146   A (q,  6);      // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 147   A (q,  7);      // { dg-warning "-Warray-bounds" "pr??????" { xfail *-*-* } }
 148   A (q,  8);      // { dg-warning "-Warray-bounds" }
 149 }