1  /* PR middle-end/91458 - inconsistent warning for writing past the end
       2     of an array member
       3     { dg-do compile }
       4     { dg-options "-O2 -fno-tree-vectorize -Wall -Wno-array-bounds -fno-ipa-icf" } */
       5  
       6  void sink (void*);
       7  
       8  // Exercise trailing one-element array members.
       9  
      10  struct A1
      11  {
      12    char n;
      13    char a[1];                    // { dg-message "destination object" "note" }
      14  };
      15  
      16  // Verify warning for access to a definition with an initializer that doesn't
      17  // initialize the one-element array member.
      18  struct A1 a1__ = { 0 };
      19  
      20  void ga1__ (void)
      21  {
      22    a1__.a[0] = 0;
      23    a1__.a[1] = 1;                 // { dg-warning "\\\[-Wstringop-overflow" }
      24    a1__.a[2] = 2;                 // { dg-warning "\\\[-Wstringop-overflow" }
      25  
      26    struct A1 a = { 1 };
      27    a.a[0] = 0;
      28    a.a[1] = 1;                    // { dg-warning "\\\[-Wstringop-overflow" }
      29    a.a[2] = 2;                    // { dg-warning "\\\[-Wstringop-overflow" }
      30    sink (&a);
      31  }
      32  
      33  // Verify warning for access to a definition with an initializer that
      34  // initializes the one-element array member to empty.
      35  struct A1 a1_0 = { 0, { } };
      36  
      37  void ga1_0_ (void)
      38  {
      39    a1_0.a[0] = 0;
      40    a1_0.a[1] = 1;                // { dg-warning "\\\[-Wstringop-overflow" }
      41    a1_0.a[2] = 2;                // { dg-warning "\\\[-Wstringop-overflow" }
      42  
      43    struct A1 a = { 1, { } };
      44    a.a[0] = 0;
      45    a.a[1] = 1;                   // { dg-warning "\\\[-Wstringop-overflow" }
      46    a.a[2] = 2;                   // { dg-warning "\\\[-Wstringop-overflow" }
      47    sink (&a);
      48  }
      49  
      50  // Verify warning for access to a definition with an initializer that
      51  // initializes the one-element array member.
      52  struct A1 a1_1 = { 0, { 1 } };
      53  
      54  void ga1_1 (void)
      55  {
      56    a1_1.a[0] = 0;
      57    a1_1.a[1] = 1;                // { dg-warning "\\\[-Wstringop-overflow" }
      58    a1_1.a[2] = 2;                // { dg-warning "\\\[-Wstringop-overflow" }
      59  
      60    struct A1 a = { 0, { 1 } };
      61    a.a[0] = 0;
      62    a.a[1] = 1;                   // { dg-warning "\\\[-Wstringop-overflow" }
      63    a.a[2] = 2;                   // { dg-warning "\\\[-Wstringop-overflow" }
      64    sink (&a);
      65  }
      66  
      67  // Exercise interior one-element array members (verify they're not
      68  // treated as trailing.
      69  
      70  struct A1i
      71  {
      72    char n;
      73    char a[1];                    // { dg-message "destination object" }
      74    char x;
      75  };
      76  
      77  // Verify warning for access to a definition with an initializer that doesn't
      78  // initialize the one-element array member.
      79  struct A1i a1i__ = { 0 };
      80  
      81  void ga1i__ (void)
      82  {
      83    a1i__.a[0] = 0;
      84    a1i__.a[1] = 1;                // { dg-warning "\\\[-Wstringop-overflow" }
      85    a1i__.a[2] = 2;                // { dg-warning "\\\[-Wstringop-overflow" }
      86  
      87    struct A1i a = { 0 };
      88    a.a[0] = 0;
      89    a.a[1] = 1;                    // { dg-warning "\\\[-Wstringop-overflow" }
      90    a.a[2] = 2;                    // { dg-warning "\\\[-Wstringop-overflow" }
      91    sink (&a);
      92  }
      93  
      94  // Verify warning for access to a definition with an initializer that
      95  // initializes the one-element array member to empty.
      96  struct A1 a1i_0 = { 0, { } };
      97  
      98  void ga1i_0_ (void)
      99  {
     100    a1i_0.a[0] = 0;
     101    a1i_0.a[1] = 1;               // { dg-warning "\\\[-Wstringop-overflow" }
     102    a1i_0.a[2] = 2;               // { dg-warning "\\\[-Wstringop-overflow" }
     103  
     104    struct A1 a = { 0, { } };
     105    a.a[0] = 0;
     106    a.a[1] = 1;                   // { dg-warning "\\\[-Wstringop-overflow" }
     107    a.a[2] = 2;                   // { dg-warning "\\\[-Wstringop-overflow" }
     108    sink (&a);
     109  }
     110  
     111  // Verify warning for access to a definition with an initializer that
     112  // initializes the one-element array member.
     113  struct A1 a1i_1 = { 0, { 1 } };
     114  
     115  void ga1i_1 (void)
     116  {
     117    a1i_1.a[0] = 0;
     118    a1i_1.a[1] = 1;               // { dg-warning "\\\[-Wstringop-overflow" }
     119    a1i_1.a[2] = 2;               // { dg-warning "\\\[-Wstringop-overflow" }
     120  
     121    struct A1 a = { 0, { 1 } };
     122    a.a[0] = 1;
     123    a.a[1] = 2;                   // { dg-warning "\\\[-Wstringop-overflow" }
     124    a.a[2] = 3;                   // { dg-warning "\\\[-Wstringop-overflow" }
     125    sink (&a);
     126  }