[RFA] Change gdbarch_return_value to take function type instead of return value type

[Andrew Cagney]

Corinna Vinschen wrote:
> On Oct 13 12:15, Corinna Vinschen wrote:
> 
>>No, I won't.  I found that my patch missed the calls of using_struct_return
>>in eval.c.  These calls only happen in case of a OP_OBJC_MSGCALL operation.
>>
>>At line 841 in eval.c, in function evaluate_subexp_standard() I found this:
>>
>>  /* If we found a method with symbol information, check to see
>>     if it returns a struct.  Otherwise assume it doesn't.  */
>>
>>  if (method)
>>    {
>>      [...]
>>      struct_return = using_struct_return (value_type, using_gcc);
>>    }
>>  else if (expect_type != NULL)
>>    {
>>      struct_return = using_struct_return (check_typedef (expect_type), using_gcc);
>>    }
>>
>>While the `if (method)' branch is simple, the `else if' branch can't be
>>solved easily.  evaluate_subexp_standard just gets the expected return type
>>as parameter.
>>
>>Does anybody know how to get around this problem?  For now I can only see
>>one way, redefine gdbarch_return_value to get both, function type and return
>>value type.
> 
> 
> Ok, since I didn't get a reply to this for a week, I take it that nobody
> has a better idea.  I've changed the patch according to my above suggestion.

I believe JimB discussed this with you off list, I might as well summarize.

For the above, just locally construct a function-type from the 
value_type / expect_type and then pass that in (ref make_function_type). 
  That both avoids the need for the extra parameter, and keeps things 
simple and consistent.

Andrew