From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on starla X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 Received: from nue.mailmanlists.eu (nue.mailmanlists.eu [94.130.110.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 59E2F1F4CC for ; Tue, 17 Dec 2024 08:45:14 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (1024-bit key; unprotected) header.d=ml.ruby-lang.org header.i=@ml.ruby-lang.org header.a=rsa-sha256 header.s=mail header.b=dxhSXpeb; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ruby-lang.org header.i=@ruby-lang.org header.a=rsa-sha256 header.s=s1 header.b=Q12qPcU1; dkim-atps=neutral DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1734425111; bh=r0SurK6rBJZokUSjHWkFw5SyjnC9kHnHstY+vdfR0mI=; h=Date:References:To:Reply-To:Subject:List-Id:List-Archive: List-Help:List-Owner:List-Post:List-Subscribe:List-Unsubscribe: From:Cc:From; b=dxhSXpebnx7M9yQeuOqm3xWZUwJRAlAKipMbkZQcK/P+bpP92YgLuPrKlKt+jxdAs 7VUW8RRRF5qA/Mm+etUHZDm6/wqGIlFE6fKUlizXZHdagTgUVNH8QFHAiFTWYc2YxJ D4XflLzfjGGc6uhaDWuwJeLNGYVT8tnOeld45klY= Received: from nue.mailmanlists.eu (localhost [IPv6:::1]) by nue.mailmanlists.eu (Postfix) with ESMTP id C74C944DB3 for ; Tue, 17 Dec 2024 08:45:11 +0000 (UTC) Authentication-Results: nue.mailmanlists.eu; dkim=pass (2048-bit key; unprotected) header.d=ruby-lang.org header.i=@ruby-lang.org header.a=rsa-sha256 header.s=s1 header.b=Q12qPcU1; dkim-atps=neutral Received: from s.wfbtzhsw.outbound-mail.sendgrid.net (s.wfbtzhsw.outbound-mail.sendgrid.net [159.183.224.105]) by nue.mailmanlists.eu (Postfix) with ESMTPS id 7D87544C4D for ; Tue, 17 Dec 2024 08:45:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ruby-lang.org; h=from:references:subject:mime-version:content-type: content-transfer-encoding:list-id:to:cc:content-type:from:subject:to; s=s1; bh=ofIknFoILIU4NQec06GY5rmOTE3ln3zYOr6nRZq9e5k=; b=Q12qPcU1sN9owQy5OWdQ9GlDmfGS9dwimqv2gTQgOC0ZgmtPZP6ocPOa7wp6xSTnqqyX eoyEzHE5PLtbVsjQhhOAwgqYXQo0BbuDn2bL8hWXF5Xdka4FchT5Z0CQM1z+QtJJCJCX0L Sj18joW/BAeDnSMUZc1XlF0/BCJQEWXvLpmeW/fOWtg9P2/vZqZ6GqdaG6uubT4fR/fOOf /yJ01I1iLaxmf+q5wp62w8TsniFEBx/XS3K+op4VByFanOqLbLn/87708l2T0DiiTfRWgl HL9FGfqeCvIUS+ehAQkip5PFf+5D4DGZz0xZcHuzgB+HTPRruegqQ8qLOG8F05eA== Received: by recvd-786d47b7ff-h42c6 with SMTP id recvd-786d47b7ff-h42c6-1-67613A13-1C 2024-12-17 08:45:07.579913626 +0000 UTC m=+2805842.773224361 Received: from herokuapp.com (unknown) by geopod-ismtpd-15 (SG) with ESMTP id GSYObLaETuC0u-X9x3xG5w for ; Tue, 17 Dec 2024 08:45:07.532 +0000 (UTC) Date: Tue, 17 Dec 2024 08:45:07 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 20205 X-Redmine-Issue-Author: byroot X-Redmine-Issue-Assignee: matz X-Redmine-Issue-Priority: Normal X-Redmine-Sender: byroot X-Mailer: Redmine X-Redmine-Host: bugs.ruby-lang.org X-Redmine-Site: Ruby Issue Tracking System X-Auto-Response-Suppress: All Auto-Submitted: auto-generated X-Redmine-MailingListIntegration-Message-Ids: 96952 X-SG-EID: =?us-ascii?Q?u001=2EKmNZ1u3n1vIpO8NNTdp+Q9c0ai7potxbEDLMO7SOJO=2F4KkRUz0d23466m?= =?us-ascii?Q?naiq=2F5fmA4hb60MdRMUAwHZnjIWVFu=2FrqiBOz5c?= =?us-ascii?Q?nOvkBudsSThLiZ6DsL0zO+dGMDuZM1bo1mF9R6r?= =?us-ascii?Q?f4Z+0j+GsC7XDVxCstJ3KhKgFQ2Tsyp1CQVIJ1L?= =?us-ascii?Q?cxAwjYnFnETXj2+UWdkpbOlQ+Z1dw5lKUrIFVOv?= =?us-ascii?Q?y=2FTWrPx1rrHU9ehRRQM9RYuUgHwuDbtcrS7UfC1?= =?us-ascii?Q?etvsuhu8Y3TrVYycazHkDtfKlQ=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: WSQX5C3A4MFG6UEMI5GO4RW3U22NLSGQ X-Message-ID-Hash: WSQX5C3A4MFG6UEMI5GO4RW3U22NLSGQ X-MailFrom: bounces+313651-b711-ruby-core=ml.ruby-lang.org@em5188.ruby-lang.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.9 Precedence: list Reply-To: Ruby developers Subject: [ruby-core:120275] [Ruby master Feature#20205] Enable `frozen_string_literal` by default List-Id: Ruby developers Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: "byroot (Jean Boussier) via ruby-core" Cc: "byroot (Jean Boussier)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Issue #20205 has been updated by byroot (Jean Boussier). Note that you don't necessarily need to set `# frozen_string_literal: true` to be compatible. Lots of code is compatible without the comment just by the virtue of not mutating literals, and some other code is compatible because it sets `#frozen_string_literal: false`. ---------------------------------------- Feature #20205: Enable `frozen_string_literal` by default https://bugs.ruby-lang.org/issues/20205#change-111042 * Author: byroot (Jean Boussier) * Status: Closed * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- ### Context The `frozen_string_literal: true` pragma was introduced in Ruby 2.3, and as far as I'm aware the plan was initially to make it the default for Ruby 3.0, but this plan was abandoned because it would be too much of a breaking change without any real further notice. According to Matz, he still wishes to enable `frozen_string_literal` by default in the future, but a reasonable migration plan is required. The main issue is backward compatibility, flipping the switch immediately would break a lot of code, so there must be some deprecation period. The usual the path forward for this kind of change is to emit deprecation warnings one of multiple versions in advance. One example of that was the Ruby 2.7 keyword argument deprecation. It was quite verbose, and some users were initially annoyed, but I think the community pulled through it and I don't seem to hear much about it anymore. So for frozen string literals, the first step would be to start warning when a string that would be frozen in the future is mutated. ### Deprecation Warning Implementation I implemented a quick proof of concept with @etienne in https://github.com/Shopify/ruby/pull/549 In short: - Files with `# frozen_string_literal: true` or `# frozen_string_literal: false` don't change in behavior at all. - Files with no `# frozen_string_literal` comment are compiled to use `putchilledstring` opcode instead of regular `putstring`. - This opcode mark the string with a user flag, when these strings are mutated, a warning is issued. Currently the proof of concept issue the warning at the mutation location, which in some case can make locating where the string was allocated a bit hard. But it is possible to improve it so the message also include the location at which the literal string was allocated, and learning from the keyword argument warning experience, we can record which warnings were already issued to avoid spamming users with duplicated warnings. As currently implemented, there is almost no overhead. If we modify the implementation to record the literal location, we'd incur a small memory overhead for each literal string in a file without an explicit `frozen_string_literal` pragma. But I believe we could do it in a way that has no overhead if `Warning[:deprecated] = false`. ### Timeline The migration would happen in 3 steps, each step can potentially last multiple releases. e.g. `R0` could be `3.4`, `R1` be `3.7` and `R2` be `4.0`. I don't have a strong opinion on the pace. - Release `R0`: introduce the deprecation warning (only if deprecation warnings enabled). - Release `R1`: make the deprecation warning show up regardless of verbosity level. - Release `R2`: make string literals frozen by default. ### Impact Given that `rubocop` is quite popular in the community and it has enforced the usage of `# frozen_string_literal: true` for years now, I suspect a large part of the actively maintained codebases in the wild wouldn't see any warnings. And with recent versions of `minitest` enabling deprecation warnings by default (and [potentially RSpec too](https://github.com/rspec/rspec-core/issues/2867)), the few that didn't migrate will likely be made compatible quickly. The real problem of course are the less actively developed libraries and applications. For such cases, any codebase can remain compatible by setting `RUBYOPT="--disable=frozen_string_literal"`, and so even after `R2` release. The flag would never be removed any legacy codebase can continue upgrading Ruby without changing a single line of cod by just flipping this flag. ### Workflow for library maintainers As a library maintainer, fixing the deprecation warnings can be as simple as prepending `# frozen_string_literal: false` at the top of all their source files, and this will keep working forever. Alternatively they can of course make their code compatible with frozen string literals. Code that is frozen string literal compatible doesn't need to explicitly declare it. Only code that need it turned of need to do so. ### Workflow for application owners For application owners, the workflow is the same than for libraries. However if they depend on a gem that hasn't updated, or that they can't upgrade it, they can run their application with `RUBYOPT="--disable=frozen_string_literal"` and it will keep working forever. Any user running into an incompatibility issue can set `RUBYOPT="--disable=frozen_string_literal"` forever, even in `4.x`, the only thing changing is the default value. And any application for which all dependencies have been made fully frozen string literal compatible can set `RUBYOPT="--enable=frozen_string_literal"` and start immediately removing magic comment from their codebase. -- https://bugs.ruby-lang.org/ ______________________________________________ ruby-core mailing list -- ruby-core@ml.ruby-lang.org To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/