From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Finalizing 'inhibit-automatic-native-compilation' Date: Sat, 28 Jan 2023 13:00:48 -0500 Message-ID: References: <837cx8cey0.fsf@gnu.org> <83357vauh5.fsf@gnu.org> <837cx6a8me.fsf@gnu.org> <83357ua6ja.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="12021"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: emacs-devel@gnu.org, akrl@sdf.org, larsi@gnus.org, rlb@defaultvalue.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jan 28 19:01:40 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pLpWF-0002wn-AW for ged-emacs-devel@m.gmane-mx.org; Sat, 28 Jan 2023 19:01:39 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pLpVd-0004IN-IB; Sat, 28 Jan 2023 13:01:01 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pLpVX-0004I0-LY for emacs-devel@gnu.org; Sat, 28 Jan 2023 13:00:55 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pLpVV-0005Lg-G0; Sat, 28 Jan 2023 13:00:55 -0500 Original-Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 8EA60441053; Sat, 28 Jan 2023 13:00:51 -0500 (EST) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id D3646441010; Sat, 28 Jan 2023 13:00:49 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1674928849; bh=ox+qAJDXKT4ICjejzLO/0gPM0GX7EoEOWMu4FIKWr24=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=nU+GPC4n74k1UboWxY+aFwSxWvahZIhC0wz4eWQWV+/ucinRDUSJ9iLztpU108zPf /2kv8Eskjeb59S/a4AbDdwAUFHQ9SHmaCBBKX5oDTFTi5PFH2356IhJdL8ZHvO1bEk /OcVya93xdg7wk71uRVhMsgnXmRDu4HWt41ql/B9NM2JAjR7p8UYxcPo4OUGBe0Jzt PhDknPVWprVWaCbUc0fjPuwHc3ELqwx/SsK35yVGLD18Iy8SWFVTXAYe+78Sh7C4ym DzYS3oHKtA3pRHVKNnoN4RUVNuCeuE7w8uk+JQONuSvpIM+ntlIEXQm91bcUeZ26K/ nRyMjgtcs2brg== Original-Received: from pastel (unknown [45.72.216.69]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 6EF32123031; Sat, 28 Jan 2023 13:00:49 -0500 (EST) In-Reply-To: <83357ua6ja.fsf@gnu.org> (Eli Zaretskii's message of "Sat, 28 Jan 2023 19:54:49 +0200") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:302726 Archived-At: >> And we do have a solution: pregenerate the trampolines. > So you are saying that the "prevent writing trampolines" part of > inhibit-automatic-native-compilation is not needed? I'm saying it's only needed temporarily, until we fix our compilation system so trampolines are pregenerated. >> >> No: what I'm suggesting is to pregenerate the trampolines before we know >> >> if we'll need them (a bit like `make trampolines`), but to place them >> >> alongside the code that might need it, so there's no additional "small" >> >> files containing nothing but a trampoline. Instead we add tiny chunks >> >> of code (the trampolines) to other `.eln` files and we do it at a time >> >> where we know we have GCC at hand. >> > What do you mean by "alongside"? The code which needs trampolines is >> > the code which advises primitives, and that is written in C. Where >> > would "alongside" be in that case? >> >> We need trampolines because we call (from .eln files) some functions via >> >> (...) >> >> instead of looking at the function cell of a symbol, checking what kind >> of Lisp_Object it holds, etc... >> >> When an advice is installed (i.e. when the function cell of the symbol >> is modified), we need to update the `functionvar` so it points to >> a trampoline which does the dance of "looking at the function cell of >> a symbol, checking what kind of Lisp_Object it holds, etc...". >> >> So, we could pregenerate the trampoline and store it directly inside the >> subr that's originally stored in the symbol's function cell. >> So instead of (comp-subr-trampoline-install SUBR) having to generate the >> trampoline, it would find it in one of the fields of the subr struct. > > Thanks, but I don't see how that answers my question. Unless by > "inside the subr" you mean we should change the implementation of > defsubr? If so, this is definitely not for Emacs 29, and we should > discuss it separately. My question about what to do with trampolines > was about Emacs 29. I'm definitely talking about a post-Emacs-29 solution here, yes. Stefan