Re: [PATCH 0/6] Conversion of gimple types to C++ inheritance (v3)

[Andrew MacLeod <amacleod@redhat.com>]

On 11/01/2013 05:57 PM, Jakub Jelinek wrote:
> On Fri, Nov 01, 2013 at 05:47:14PM -0400, Andrew MacLeod wrote:
>> On 11/01/2013 05:41 PM, Jakub Jelinek wrote:
>>> On Fri, Nov 01, 2013 at 05:36:34PM -0400, Andrew MacLeod wrote:
>>>>    static inline void
>>>> ! gimple_call_set_lhs (gimple gs, tree lhs)
>>>>    {
>>>> -   GIMPLE_CHECK (gs, GIMPLE_CALL);
> The checking you are removing here.
>
>> What checking?  There ought to be no checking at all in this
>> example...  gimple_build_call_vec returns a gimple_call, and
>> gimple_call_set_lhs()  doesn't have to check anything because it
>> only accepts gimple_call's.. so there is no checking other than the
>> usual "does my parameter match" that the compiler has to do...
> and want to replace it by checking of the types at compile time.
> The problem is that it uglifies the source too much, and, when you
> actually don't have a gimple_call but supposedly a base class of it,

But when you convert all the source base for gimple calls, then you have 
context pretty much everywhere.. you wont be doing it from a base 
class...  at least pretty infrequently.
> I expect you'd do as_a which is not only further uglification, but has
> runtime cost also for --enable-checking=release.
>
> 	
Im not a fan of as_a<> or is_a<> at all.  I really dislike them. They 
should be kept to the barest minimum, or even non existent if 
possible.....   If you need it, you probably need restructured source.  
ie, functions which work with switches on gimple_code() need to be 
restructured... And the end result should look cleaner.

Of course, thats what makes it a big project too :-)

Andrew