gcc/testsuite/gcc.dg/lvalue-2.c

   1 /* Test diagnostic messages for invalid lvalues and non-modifiable
   2    lvalues.  */
   3 /* Origin: Joseph Myers <jsm@polyomino.org.uk> */
   4 /* { dg-do compile } */
   5 /* { dg-options "" } */
   6
   7 int a, b;
   8
   9 void
  10 f0 (void)
  11 {
  12   (a+b) = 1; /* { dg-error "lvalue required as left operand of assignment" } */
  13   (a+b)++; /* { dg-error "lvalue required as increment operand" } */
  14   ++(a+b); /* { dg-error "lvalue required as increment operand" } */
  15   (a+b)--; /* { dg-error "lvalue required as decrement operand" } */
  16   --(a+b); /* { dg-error "lvalue required as decrement operand" } */
  17   &(a+b); /* { dg-error "lvalue required as unary '&' operand" } */
  18 }
  19
  20 const int c;
  21 const struct { int x; } d;
  22 struct { const int x; } e;
  23 const int *f;
  24
  25 void
  26 f1 (void)
  27 {
  28   c = 1; /* { dg-error "assignment of read-only variable 'c'" } */
  29   d.x = 1; /* { dg-error "assignment of member 'x' in read-only object" } */
  30   e.x = 1; /* { dg-error "assignment of read-only member 'x'" } */
  31   *f = 1; /* { dg-error "assignment of read-only location" } */
  32   c++; /* { dg-error "increment of read-only variable 'c'" } */
  33   d.x++; /* { dg-error "increment of member 'x' in read-only object" } */
  34   e.x++; /* { dg-error "increment of read-only member 'x'" } */
  35   (*f)++; /* { dg-error "increment of read-only location" } */
  36   ++c; /* { dg-error "increment of read-only variable 'c'" } */
  37   ++d.x; /* { dg-error "increment of member 'x' in read-only object" } */
  38   ++e.x; /* { dg-error "increment of read-only member 'x'" } */
  39   ++(*f); /* { dg-error "increment of read-only location" } */
  40   c--; /* { dg-error "decrement of read-only variable 'c'" } */
  41   d.x--; /* { dg-error "decrement of member 'x' in read-only object" } */
  42   e.x--; /* { dg-error "decrement of read-only member 'x'" } */
  43   (*f)--; /* { dg-error "decrement of read-only location" } */
  44   --c; /* { dg-error "decrement of read-only variable 'c'" } */
  45   --d.x; /* { dg-error "decrement of member 'x' in read-only object" } */
  46   --e.x; /* { dg-error "decrement of read-only member 'x'" } */
  47   --(*f); /* { dg-error "decrement of read-only location" } */
  48 }