Re: [Re: new plugin events]

[Richard Guenther <richard dot guenther at gmail dot com>]

On Sun, Nov 8, 2009 at 6:35 PM, Terrence Miller <terrencem@sbcglobal.net> wrote:
> < Forwarded due to missing address>
>
> -------- Original Message --------
> Subject: ? ? ? ?Re: new plugin events
> Date: ? Sun, 08 Nov 2009 18:25:21 +0100
> From: ? Basile STARYNKEVITCH <basile@starynkevitch.net>
> To: ? ? Terrence Miller <terrencem@sbcglobal.net>
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>
> Terrence Miller wrote:
>>
>> I think this debate is missing one important issue. In order to generate a
>> patch to GCC
>> you have to know a lot more about the compiler internals than is required
>> to create
>> a plugin. ?I am doing some casual experimentation with compiler based
>> source browsing
>> and would love to have the DECL event(described below) added to the plugin
>> API.
>> I would prefer to not have to figure where that plugin should be called.
>>
>
> It is perhaps true for the DECL event you are talking about (which I did not
> understood fully), but I won't say that coding a plugin is *in general*
> easier than proposing a patch to core GCC.
>
> My perception is that most *middle* end plugins are working on Gimple and
> other middle-end representations. Usually, they do that by adding a pass in
> the pass machinery. And knowing what pass to add (or replace) is as
> difficult when coding a plugin than when coding a patch to GCC core.
>
> Conversely, I would suspect than many previous patches (which have now bee
> incorporated in GCC core) could have if a plugin machinery have been
> available at their time (which is false since plugin facilities is just
> coming in 4.5 which has not yet been released), first been developped as
> plugins -at least to experiment their viability & interest- and later one
> proposed as a patch.
>
> This is why I believe that plugins will probably -at least for middle-end
> processing- have also the role of GCC branches today, with a very important
> difference. Almost nobody compiles branches today (in the general GCC user
> community - I am not talking of the smaller GCC developper community), and
> it could be the case that some plugins will be used.
>
> For example, as far as I know, no common Linux distribution provides a
> package for any kind of GCC branch. I believe (perhaps I am too optimistic)
> that some Linux distributions will package some few GCC plugins.

You keep re-iterating this (IMHO bogus) argument.  I don't see how a plugin
in development is any different here - nobody will build or distribute it.
OTOH after a branch is mature it will be merged into the GCC core, so it
will be immediately available in distributed GCCs.

Richard.