From: Andrea Corallo <akrl@sdf.org>
To: Alan Mackenzie <acm@muc.de>
Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org
Subject: Re: Correct byte compiler error/warning positions. The solution!
Date: Wed, 15 Dec 2021 09:33:45 +0000 [thread overview]
Message-ID: <xjfilvqrz46.fsf@ma.sdf.org> (raw)
In-Reply-To: <YbiqS1v+6upfUwrr@ACM> (Alan Mackenzie's message of "Tue, 14 Dec 2021 14:29:31 +0000")
Alan Mackenzie <acm@muc.de> writes:
> Hello, Andrea.
>
> On Sat, Dec 04, 2021 at 19:22:02 +0000, Andrea Corallo wrote:
>> Alan Mackenzie <acm@muc.de> writes:
>
> [ .... ]
>
>> Hi Alan,
>
>> > For extending emit_EQ, I've got the following embryonic scheme:
>
>> > 1/- Import the C variable symbols_with_pos_enabled:
>
>> > gcc_jit_lvalue *syms_with_pos_enabled =
>> > gcc_jit_context_new_global
>> > (comp.ctxt, NULL,
>> > GCC_JIT_GLOBAL_IMPORTED,
>> > gcc_jit_get_type (comp.ctxt, GCC_JIT_TYPE_BOOL),
>> > "symbols_with_pos_enabled");
>
>> Yep something like. PS We already have 'comp.bool_type' to use.
>
> [ .... ]
>
>> > Can you let me know what you think of this approach, please? That is,
>> > before I put a lot of work into it. Is it broadly a good way of doing
>> > the job?
>
>> I think it could be a good idea but I believe there's no need to use
>> macros here, we could have just functions return rvalues no?
>
> Yes, no macros needed. :-)
>
>> I'm not a big fan of C macros and I try not to use them whem possible.
>
> [ .... ]
>
> I have a problem at the moment, which could be a big problem. How do I
> refer to a Lisp variable from jit generated code?
>
> In particular, I need read-access to symbols-with-pos-enabled, or more
> precisely to globals.f_symbols_with_pos_enabled.
>
> The gcc jit product seems to go out of its way to make such access as
> difficult as possible. There is a way to get an integer out of "C space"
> into the jit mechanism, but this cannot be cast to a pointer type, and
> there is no similar mechanism to get a pointer out of C space. In fact,
> gcc jit seems to restrict the language it supports to the equivalent of
> Pascal, and makes pointer arithmetic impossible.
>
> I tried declaring "globals" as a global variable to be imported into jit
> space, but the loader doesn't know about "globals".
>
> So, how can I get access to globals.f_symbols_with_pos_enabled?
>
> Thanks in advance!
Hi Alan,
I think the way should be done is that one declare in the .eln a global
variable as a (bool *), say 'f_symbols_with_pos_enabled_ref'. Then
during eln load time we set into that the correct address of
'globals.f_symbols_with_pos_enabled' so it can be used as
'*f_symbols_with_pos_enabled_ref' by the generated code.
We do something very similar for the Emacs global var 'current_thread'.
In the eln we have a global variable named "current_thread_reloc" where
we store the address of 'current_thread'. You can see we set this value
during eln load in 'load_comp_unit'.
Just grep CURRENT_THREAD_RELOC_SYM and you should find the relevant
pieces of code you are interested in.
Best Regards
Andrea
next prev parent reply other threads:[~2021-12-15 9:33 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-26 19:56 Correct byte compiler error/warning positions. The solution! Alan Mackenzie
2021-11-27 5:53 ` Eli Zaretskii
2021-11-27 9:31 ` Alan Mackenzie
2021-11-27 10:07 ` Eli Zaretskii
2021-11-27 10:33 ` Alan Mackenzie
2021-11-27 10:51 ` Eli Zaretskii
2021-11-27 23:05 ` Alan Mackenzie
2021-11-28 7:25 ` Eli Zaretskii
2021-11-29 11:50 ` Alan Mackenzie
2021-11-29 12:45 ` Eli Zaretskii
2021-11-29 19:39 ` Alan Mackenzie
2021-12-01 15:58 ` Alan Mackenzie
2021-12-01 16:49 ` Eli Zaretskii
2021-12-01 16:58 ` Alan Mackenzie
2021-12-01 17:04 ` Lars Ingebrigtsen
2021-12-01 17:21 ` Alan Mackenzie
2021-12-01 17:38 ` Lars Ingebrigtsen
2021-12-01 20:28 ` Alan Mackenzie
2021-12-01 17:08 ` Eli Zaretskii
2021-12-01 17:12 ` Alan Mackenzie
2021-12-01 17:53 ` Andrea Corallo
2021-12-01 17:57 ` Eli Zaretskii
2021-12-02 11:21 ` Alan Mackenzie
2021-12-02 16:31 ` Andrea Corallo
2021-12-02 20:35 ` Alan Mackenzie
2021-12-03 21:05 ` Alan Mackenzie
2021-12-04 19:22 ` Andrea Corallo
2021-12-04 19:39 ` Eli Zaretskii
2021-12-04 19:55 ` Andrea Corallo
2021-12-04 19:58 ` Eli Zaretskii
2021-12-04 20:06 ` Andrea Corallo
2021-12-14 14:29 ` Alan Mackenzie
2021-12-15 9:33 ` Andrea Corallo [this message]
2021-12-17 11:54 ` Alan Mackenzie
2021-12-20 8:24 ` Andrea Corallo
2021-12-21 17:48 ` Alan Mackenzie
2021-11-29 13:24 ` Robert Pluim
2021-11-29 19:16 ` Alan Mackenzie
2021-11-30 9:52 ` Robert Pluim
2021-11-28 20:15 ` Andrea Corallo
2021-12-01 16:18 ` Andrea Corallo
2021-12-01 16:46 ` Alan Mackenzie
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xjfilvqrz46.fsf@ma.sdf.org \
--to=akrl@sdf.org \
--cc=acm@muc.de \
--cc=eliz@gnu.org \
--cc=emacs-devel@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).