1  /* Test wrong usage of C23 nullptr.  */
       2  /* { dg-do compile } */
       3  /* { dg-options "-std=c2x -pedantic-errors -Wall -Wextra -Wno-unused-variable" } */
       4  
       5  typedef __typeof__(nullptr) nullptr_t;
       6  
       7  void g (nullptr_t); /* { dg-message "expected .nullptr_t. but argument is of type .int." } */
       8  nullptr_t cmp (void);
       9  
      10  void
      11  test1 (int *p)
      12  {
      13    (void) (p > nullptr); /* { dg-error "ordered comparison" } */
      14    (void) (p >= nullptr); /* { dg-error "ordered comparison" } */
      15    (void) (p < nullptr); /* { dg-error "ordered comparison" } */
      16    (void) (p <= nullptr); /* { dg-error "ordered comparison" } */
      17    (void) (nullptr == 1); /* { dg-error "invalid operands" } */
      18    (void) (1 == nullptr); /* { dg-error "invalid operands" } */
      19    (void) (nullptr != 1); /* { dg-error "invalid operands" } */
      20    (void) (1 != nullptr); /* { dg-error "invalid operands" } */
      21    (void) (1 > nullptr); /* { dg-error "invalid operands" } */
      22  }
      23  
      24  void
      25  test2 (void)
      26  {
      27    const nullptr_t nptr = nullptr;
      28    int p = nullptr; /* { dg-error "incompatible types" } */
      29    float d = nullptr; /* { dg-error "incompatible types" } */
      30    char arr[10] = { nullptr }; /* { dg-error "incompatible types" } */
      31  
      32    /* Unary '+' is not valid for nullptr.  */
      33    +nullptr; /* { dg-error "wrong type argument to unary plus" } */
      34  
      35    g (0.0); /* { dg-error "incompatible type" } */
      36    g (1); /* { dg-error "incompatible type" } */
      37    g ((int) (float) 0.0); /* { dg-error "incompatible type" } */
      38    int i = 42 + nullptr; /* { dg-error "invalid operands" } */
      39  
      40    /* The assignment of an object of type nullptr_t with a value of another
      41       type, other than a null pointer constant, is a constraint
      42       violation.  */
      43    nullptr_t m;
      44    m = 1; /* { dg-error "incompatible types" } */
      45    m = 0.0; /* { dg-error "incompatible types" } */
      46    (void) m;
      47    nullptr_t o = 1; /* { dg-error "incompatible types" } */
      48    (nullptr_t) 0.0; /* { dg-error "conversion" } */
      49    (nullptr_t) (int) (float) 0.0; /* { dg-error "conversion" } */
      50  
      51    switch (nullptr); /* { dg-error "switch quantity not an integer" } */
      52  }
      53  
      54  /* If a second or third operand of type nullptr_t is used that is not a null
      55     pointer constant and the other operand is not a pointer or does not have
      56     itself nullptr_t, a constraint is violated even if that other operand is
      57     a null pointer constant such as 0.  */
      58  void
      59  test3 (_Bool b, int i)
      60  {
      61    const nullptr_t nptr = nullptr;
      62    __auto_type a1 = b ? nptr : i; /* { dg-error "type mismatch" } */
      63    __auto_type a2 = b ? i : nptr; /* { dg-error "type mismatch" } */
      64    __auto_type a3 = b ? nptr : 0; /* { dg-error "type mismatch" } */
      65    __auto_type a4 = b ? 0 : nptr; /* { dg-error "type mismatch" } */
      66    __auto_type a5 = b ? 0 : nullptr; /* { dg-error "type mismatch" } */
      67    __auto_type a6 = b ? nullptr : 0; /* { dg-error "type mismatch" } */
      68  }