GTY as attributes

[Basile STARYNKEVITCH]

Taras Glek wrote:
> 
> Would you consider restructuring GTY markers to be more like GCC 
> attributes? 

It could have some advantages, but if I understand what you mean it 
would make sense only on platforms where GCC is compiled by itself. I 
believe that (perhaps unfortunately) the rule is that GCC should be 
compilable by any ISO-C conformant compiler.

> I'm writing code to generate code to convert GCC trees to 
> JavaScript objects for my GCC plugin. Clearly this is similar to what 
> gengtype does. However, I would like to reuse GTY markers without using 
> the gengtype parser. Since I already use the GCC asts, it would be handy 
> if GTYs were just gnu attributes.
> 
> I think it was also be beneficial to do GTYs as gcc attributes for 
> consistency instead of having yet another language extension.
> 
> So far I've defined GTY as
> #define GTY(x) __attribute__((user (#x)))
> 
> Which appears to work for most cases except for numerous cases of
> 
> typedef struct Name GTY(()) {
> };
> 
> These would parse fine as attributes if they were more like
> 
> typedef struct GTY(()) Name  {
> };

Maybe you might patch gengtype to accept such a change, and be able to 
parse the above? Then you only have to (trivially) patch all the files 
so that typedef struct Name GTY(()) is changed to
typedef struct GTY(()) Name


> Would you be willing to accept such a change?
> 
> Another possible benefit of raising GTYs to attribute status would be 
> that other projects could do compile-time reflection similar to what GCC 
> does in a semi-formal way.

This would be interesting (including for my MELT branch)

A more disruptive technique would be to have all the data defined with 
GTY described (perhaps more precisely) elsewhere. I mean to have all the 
GGC handled data described -probably in a different syntax- elsewhere, 
and having all the struct and GGC routines generated otherwise.

Regards
-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
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