Re: [PATCH][gdb/exp] Fix assert when adding ptr to imaginary unit

[Tom de Vries <tdevries@suse.de>]

On 1/29/21 8:10 AM, Tom de Vries wrote:
> On 1/29/21 8:04 AM, Tom de Vries wrote:
>> On 1/28/21 3:08 PM, Tom Tromey wrote:
>>>>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:
>>>
>>> Tom> 2021-01-28  Tom de Vries  <tdevries@suse.de>
>>>
>>> Tom> 	PR exp/27265
>>> Tom> 	* valarith.c (scalar_binop): Don't call complex_binop unless
>>> Tom> 	arguments are either complex or can be casted to complex.
>>>
>>> Thanks for doing this.
>>>
>>> Tom> +  if ((type1->code () == TYPE_CODE_COMPLEX
>>> Tom> +       && (type2->code () == TYPE_CODE_COMPLEX
>>> Tom> +	   || type2->code () == TYPE_CODE_INT
>>> Tom> +	   || type2->code () == TYPE_CODE_FLT))
>>> Tom> +      || ((type2->code () == TYPE_CODE_COMPLEX
>>> Tom> +	   && (type1->code () == TYPE_CODE_COMPLEX
>>> Tom> +	       || type1->code () == TYPE_CODE_INT
>>> Tom> +	       || type1->code () == TYPE_CODE_FLT))))
>>> Tom>      return complex_binop (arg1, arg2, op);
>>>
>>> Maybe it should use is_floating_type || is_integral_type instead?
>>> is_scalar_type sounds like it should be right but does something really
>>> different instead.  That function looks suspect to me.
>>>
>>> This approach would still rule out fixed point.  I'm not sure if that's
>>> ok to do though.
>>>
>>> Also weirdly, is_fixed_point_type looks through TYPE_CODE_RANGE (seems
>>> reasonable) but is_integral_type does not (seems wrong).
>>>
>>
>> I managed to create an example using TYPE_CODE_BOOL that used to work
>> but was broken by this patch, added it to the tests in the patch.
>>
>> I've now gone a different route: instead of trying to narrow down when
>> complex_binop can be called, detect the error situation in complex_bin
>> and throw an error.
>>
>> That avoids speculation about what type is left after promotion.
>> Instead, we just check the type after promotion.
>>
>> WDYT?
> 
> And FWIW, this WIP follow-up patch enables decimal float complex well
> enough to do "print (_Decimal32)0 + 5i".
> 

Filed as PR27350 - Support complex decimal float (
https://sourceware.org/bugzilla/show_bug.cgi?id=27350 ).

Thanks,
- Tom