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, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 Received: from nue.mailmanlists.eu (nue.mailmanlists.eu [IPv6:2a01:4f8:1c0c:6b10::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id EA53F1F405 for ; Wed, 24 Jan 2024 09:46:29 +0000 (UTC) Authentication-Results: dcvr.yhbt.net; dkim=pass (1024-bit key; secure) header.d=ml.ruby-lang.org header.i=@ml.ruby-lang.org header.a=rsa-sha256 header.s=mail header.b=FcGCnNqD; 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=neXO7jJ3; dkim-atps=neutral Received: from nue.mailmanlists.eu (localhost [127.0.0.1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 2C1DC81F08; Wed, 24 Jan 2024 09:46:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1706089584; bh=+lLTa7JRzn2Quo1EmMB5kDlflL1u/dMI9p02kVsQtpM=; 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=FcGCnNqDS4uFsrW8Af+rXShTj82Thy7iqVQfQNSgH6xgkbIZsyHB8zgHzn+orhntT KEHwmRCsQ6q4Ciio2JQO0KrY4RRishCme5i5eCCoPOHsmk82iBAZw14qhYs9vbRN6s BQS74zfSy46zuBKdC0O5ayDyYDXTJt3fg3MR9mB4= Received: from csnrwnwx.outbound-mail.sendgrid.net (csnrwnwx.outbound-mail.sendgrid.net [198.37.146.154]) by nue.mailmanlists.eu (Postfix) with ESMTPS id A1E0B81DC4 for ; Wed, 24 Jan 2024 09:46:21 +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=neXO7jJ3; dkim-atps=neutral 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=2Q2XonugwvMY/boM164GfBXnIGf5p6R6Or4Gt3OGGKY=; b=neXO7jJ3zc9PJqjok+d76WONUWDOgF29pTmaXEaSNpXmexdJqN3UVSg6EmeEXVeiggOg w935MCAOBGkmYBzC2qaPJ0DEUx12B72vdwudM2p8WqcCFLRi/bBahs84rgcD44qUPePJcP 4wxpcJijPQVv9RXSqvyZD3UYfM3Rw1IzLvcIKr5WYH8woO/TBhvUEc5Q3IUws8tujXMOdd zvZ98Qj5L+XfRkCCLaHQMGXfuBrRtts4wbBVgCbtepkQPVWS6MNFSYQwUbH7PVrKS/pMM/ 3MMpWg0LUi3wXPwGV0lri3u/WDnUwfuYY+Eo507XRQfFJkqrhQvkKwCnBcDPMqlg== Received: by filterdrecv-58bfc74dd6-r8bz2 with SMTP id filterdrecv-58bfc74dd6-r8bz2-1-65B0DC6B-1E 2024-01-24 09:46:19.680518591 +0000 UTC m=+68326.333143008 Received: from herokuapp.com (unknown) by geopod-ismtpd-2 (SG) with ESMTP id Hr4qAu2nSoKOQfeI_WsMQw for ; Wed, 24 Jan 2024 09:46:19.641 +0000 (UTC) Date: Wed, 24 Jan 2024 09:46:19 +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-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: 92955 X-SG-EID: =?us-ascii?Q?Dq8GNIcVqP8cs5uR+EIAabfg3LE9XdC6dZ5KYNrMpf6VzBWG6HqArcu5raQjXL?= =?us-ascii?Q?IGTFdxKHUt7++67+KD54pNYXheirMcsUIf3sdgF?= =?us-ascii?Q?Riq06gaKqIGhrb0+3=2FQdqGgujLbQbS1eLKkb6Is?= =?us-ascii?Q?22IcHKXpv0MCp8qkc2jknwLeuMVB3sljdJNKhLb?= =?us-ascii?Q?LMNCutZgTpSOGYx1l5yo2991SMy5pXmecqTLg4=2F?= =?us-ascii?Q?CGRMwMcQU13+OkeGU0KwEUGyu2ZcOjirsb7=2F8GC?= =?us-ascii?Q?GIZlSEMo5Ow4zwD4GaVHw=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: b/2+PoftWZ6GuOu3b0IycA== Message-ID-Hash: EWQ7OCQIL4XAC3Z76YBDSBFBYXXCNSBD X-Message-ID-Hash: EWQ7OCQIL4XAC3Z76YBDSBFBYXXCNSBD 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: 3.3.3 Precedence: list Reply-To: Ruby developers Subject: [ruby-core:116398] [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). > but because standardrb doesn't enforce it (and many folks have been defaulting to that), I've seen several codebases not consistently using the pragma. Yes, I didn't extend on my motivations for bringing this now, but It's in big part influenced by `standardrb` and some other communities starting to discourage the use of frozen string literals. I suspect many people are starting to be fed up with that magic comment and we probably reached peak usage of it. ---------------------------------------- Feature #20205: Enable `frozen_string_literal` by default https://bugs.ruby-lang.org/issues/20205#change-106420 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### 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/postorius/lists/ruby-core.ml.ruby-lang.org/