gcc/testsuite/gcc.dg/Warray-bounds-61.c

   1 /* PR middle-end/94940 - spurious -Warray-bounds for a zero length array
   2    member of union
   3    { dg-do compile }
   4    { dg-options "-O2 -Wall" } */
   5
   6 extern int n;
   7
   8 extern union Ua3_a0 {
   9   int a3[3];
  10   int a2[2];                  // can only alias a3[0 - 2]
  11   int a1[1];                  // can alias all of the union
  12   int a0[0];                  // ditto
  13 } ua3_a0;
  14
  15 void test_ua3_ua0_a0 (int i)
  16 {
  17   ua3_a0.a0[0] = 0;           // { dg-bogus "\\\[-Warray-bounds" }
  18   ua3_a0.a0[1] = 0;           // { dg-bogus "\\\[-Warray-bounds" }
  19   ua3_a0.a0[2] = 0;           // { dg-bogus "\\\[-Warray-bounds" }
  20   ua3_a0.a0[3] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  21   ua3_a0.a0[4] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  22   ua3_a0.a0[i] = 0;           // { dg-bogus "\\\[-Warray-bounds" }
  23
  24   if (i < __LINE__)
  25     i = 5;
  26   ua3_a0.a0[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  27
  28   if (i > -1)
  29     i = -1;
  30   ua3_a0.a0[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  31 }
  32
  33 void test_ua3_ua0_a1 (int i)
  34 {
  35   /* Abusing one-element array members the same way as those of
  36      length zero is discouraged but so far acceted without warnings.
  37      This should change at some point.  */
  38
  39   ua3_a0.a1[0] = 0;
  40   ua3_a0.a1[1] = 0;
  41   ua3_a0.a1[2] = 0;
  42   ua3_a0.a1[3] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  43   ua3_a0.a1[i] = 0;
  44
  45   if (i > -1)
  46     i = -1;
  47   ua3_a0.a1[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  48
  49   if (i < 7)
  50     i = 7;
  51   ua3_a0.a1[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  52 }
  53
  54 void test_ua3_ua0_a2 (int i)
  55 {
  56   ua3_a0.a2[0] = 0;
  57   ua3_a0.a2[1] = 0;
  58   ua3_a0.a2[2] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  59   ua3_a0.a2[i] = 0;
  60
  61   if (i < __LINE__)
  62     i = __LINE__;
  63   ua3_a0.a2[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  64
  65   if (i > -1)
  66     i = -1;
  67   ua3_a0.a2[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  68 }
  69
  70
  71 extern union Ua2_a3 {
  72   int a2[2];                  // can only alias a3[0 - 1]
  73   int a3[3];
  74 } ua2_a3;
  75
  76 void test_ua2_ua3 (int i)
  77 {
  78   ua2_a3.a2[0] = 0;           // { dg-bogus "\\\[-Warray-bounds" }
  79   ua2_a3.a2[1] = 0;           // { dg-bogus "\\\[-Warray-bounds" }
  80   ua2_a3.a2[2] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  81   ua2_a3.a2[i] = 0;
  82
  83   if (i < __LINE__)
  84     i = __LINE__;
  85   ua2_a3.a2[i] = 0;           // { dg-warning "\\\[-Warray-bounds" }
  86 }
  87
  88
  89 extern struct SUa2_a0 {
  90   union Ua2_a0 {
  91     int a2[2];
  92     int a0[0];
  93   } u;
  94 } sua2_a0;
  95
  96 void test_sua2_sua0 (int i)
  97 {
  98   n += sua2_a0.u.a0[0];
  99   n += sua2_a0.u.a0[1];
 100   n += sua2_a0.u.a0[2];       // { dg-warning "\\\[-Warray-bounds" }
 101   n += sua2_a0.u.a0[i];
 102
 103   if (i < __LINE__)
 104     i = __LINE__;
 105   n += sua2_a0.u.a0[i];       // { dg-warning "\\\[-Warray-bounds" }
 106 }
 107
 108 void test_sua2_sua0_ptr (int i)
 109 {
 110   union Ua2_a0 *p = &sua2_a0.u;
 111
 112   n += p->a0[0];
 113   n += p->a0[1];
 114   n += p->a0[2];              // { dg-warning "\\\[-Warray-bounds" }
 115   n += p->a0[i];
 116 }
 117
 118
 119 extern struct SUSa3_a0 {
 120   union USa3_a0 {
 121     struct {
 122       int a3[3];
 123     } s;
 124     int a2[2];                // can alias s.a3[0 - 2]
 125     int a1[1];                // can alias s.a3[0 - 2]
 126     int a0[0];                // can alias s.a3[0]
 127   } u;
 128 } susa3_ua0;
 129
 130 void test_susa3_sua0 (int i, int j)
 131 {
 132   n += susa3_ua0.u.a0[0];
 133   n += susa3_ua0.u.a0[1];
 134   n += susa3_ua0.u.a0[2];
 135   n += susa3_ua0.u.a0[3];     // { dg-warning "\\\[-Warray-bounds" }
 136 }
 137
 138 void test_susa3_sua0_ptr (int i, int j)
 139 {
 140   union USa3_a0 *p = &susa3_ua0.u;
 141   n += p->a0[0];
 142   n += p->a0[1];
 143   n += p->a0[2];
 144   n += p->a0[3];              // { dg-warning "\\\[-Warray-bounds" }
 145 }
 146
 147 void test_susa3_sua1 (int i)
 148 {
 149   n += susa3_ua0.u.a1[0];
 150   n += susa3_ua0.u.a1[1];
 151   n += susa3_ua0.u.a1[2];
 152   n += susa3_ua0.u.a1[3];     // { dg-warning "\\\[-Warray-bounds" }
 153
 154   if (i < __LINE__)
 155     i = __LINE__;
 156   n += susa3_ua0.u.a1[i];     // { dg-warning "\\\[-Warray-bounds" }
 157 }
 158
 159 void test_susa3_sua2 (void)
 160 {
 161   n += susa3_ua0.u.a2[0];
 162   n += susa3_ua0.u.a2[1];
 163   n += susa3_ua0.u.a2[2];     // { dg-warning "\\\[-Warray-bounds" }
 164   n += susa3_ua0.u.a2[3];     // { dg-warning "\\\[-Warray-bounds" }
 165 }
 166
 167
 168 extern struct {
 169   union {
 170     struct {
 171       int a3[3];
 172     } s1;
 173     struct {
 174       int a0[0];
 175     } s2;
 176   } u;
 177 } susa3_usa0;
 178
 179 void test_susi3_susi0 (int i)
 180 {
 181   n += susa3_usa0.u.s2.a0[0];
 182   n += susa3_usa0.u.s2.a0[1];
 183   n += susa3_usa0.u.s2.a0[2];
 184   n += susa3_usa0.u.s2.a0[3]; // { dg-warning "\\\[-Warray-bounds" }
 185   n += susa3_usa0.u.s2.a0[i];
 186
 187   if (i < __LINE__)
 188     i = __LINE__;
 189   n += susa3_usa0.u.s2.a0[i]; // { dg-warning "\\\[-Warray-bounds" }
 190 }