[patch, fortran] PR 46659 - extend conversion warnings to assignments

[Tobias Burnus]

On 08/15/2011 07:49 PM, Thomas Koenig wrote:
> Am 14.08.2011 22:54, schrieb Tobias Burnus:
>> Thomas Koenig wrote:
>>> the attached patch extends conversion warnings to assignments.
>>> OK for trunk?
>>
>> I get now two warnings for:
>>
>> complex(8), parameter :: z = cmplx (0.5, 0.5)
>> r = z
>> end
>
> The problem is that gfc_check_assign is called twice for this, from
> different code paths

Well, I don't think that this is the problem - the actual warning comes 
from the calling of the same code path:

a) Call to gfc_check_assign_symbol from add_init_expr_to_sym: This does 
not print a warning for "z = cmplx(0.5,0.5)"  (Side note: There is a 
conversion from kind=4 to kind=8)

b) Call from gfc_resolve for "r = z"
b.1) gfc_warning call in gfc_check_assign at expr.c:3228  -- the code 
which you added
b.2) gfc_warning_now call in gfc_convert_type_warn (intrinsic.c:4349), 
which is called from gfc_check_assign (line 3272).

(b.2) is guarded by
       else if (from_ts.type == ts->type
                || (from_ts.type == BT_INTEGER && ts->type == BT_REAL)
                || (from_ts.type == BT_INTEGER && ts->type == BT_COMPLEX)
                || (from_ts.type == BT_REAL && ts->type == BT_COMPLEX))

while (b.1) uses
   if (rvalue->expr_type == EXPR_CONSTANT
&& (lvalue->ts.type == BT_REAL || lvalue->ts.type == BT_COMPLEX)
&& (rvalue->ts.type == BT_REAL || rvalue->ts.type == BT_COMPLEX))

As written, you should consider changing this to, e.g.,

   if (rvalue->expr_type == EXPR_CONSTANT
&& (lvalue->ts.type == BT_REAL || lvalue->ts.type == BT_COMPLEX)
&& (rvalue->ts.type == rvalue->ts.type))

or at least you should exclude rvalue == BT_COMPLX and lvalue == BT_REAL.


Tobias