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=0.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_BL_SPAMCOP_NET,SPF_HELO_PASS, SPF_PASS autolearn=no 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 819891F518 for ; Fri, 24 May 2024 00:02:20 +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=0/F3I/oM; 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=FWRKgEfV; dkim-atps=neutral Received: from nue.mailmanlists.eu (localhost [127.0.0.1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 338968613D; Thu, 23 May 2024 18:00:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1716487244; bh=Wjly1xxXUJpLXqS0yWJ7P+juSTZeL+guJX27kHdcZak=; 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=0/F3I/oMwkDTleZaIU6OcxpKCPPiAKREO+mWJL22Ha4Hkbht3Vu0qZsUgHqAEwBIk 74J2K3JW7VDZyNdHsPUwK+v8WjYVkiY5IysIECs7ocZglCLfQaYdEhprYba0KvT2Bx YLp4kKUB1QqnACdHWlPY3CQdxd0pAeHvQhU9kNcs= Received: from s.wrqvtvvn.outbound-mail.sendgrid.net (s.wrqvtvvn.outbound-mail.sendgrid.net [149.72.120.130]) by nue.mailmanlists.eu (Postfix) with ESMTPS id D25E786127 for ; Thu, 23 May 2024 18:00:40 +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=FWRKgEfV; 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=sD53c9iqXxoGZcTsqLihQ+633NsghG2GyYq7M8ZZtLM=; b=FWRKgEfVzzn/oQKQCTWVpjlKlTDOtJegkINg4tau1U03Q76xhURYuWlcyRVKJC7JJ3Lg obeZ+GOK/WmM2OQ0fmDeI+9oRiCC7tj4Aad2Bz1qvzpY7KMrgm6WLIemlrrJAZY+QWdvgV GFVk1NVQWR+L7IMVj1eAPpWbkc3XZdZFKuChFiUPucof99VZexf6XWWSDyNr+JS4Ft6CVR 7ZiScpaV4Fah5xuQRKVJJ6QbbDjXNqGrczHGQhh4rnSkgWjyCagaAY0rPzkqkg1D6LuhDv f/K0X6rc3mcMtnC3r0+DplR1WvHzVihOzIuOLUfW4iyMy9eV9p80NdqPjyCENakQ== Received: by recvd-6d78dbc954-tm924 with SMTP id recvd-6d78dbc954-tm924-1-664F8447-2E 2024-05-23 18:00:39.600332437 +0000 UTC m=+1966154.614969346 Received: from herokuapp.com (unknown) by geopod-ismtpd-4 (SG) with ESMTP id dT5kj9AxTMu0vI6Hlwob_g for ; Thu, 23 May 2024 18:00:39.594 +0000 (UTC) Date: Thu, 23 May 2024 18:00:39 +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-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: 94587 X-SG-EID: =?us-ascii?Q?u001=2EKmNZ1u3n1vIpO8NNTdp+Q9c0ai7potxbEDLMO7SOJO=2F4KkRUz0d23466m?= =?us-ascii?Q?naiq=2F5fmA4hb60MdRMUAwHZnjIWVFu=2FrqiBOz5c?= =?us-ascii?Q?nOvkBudsSTjshupKL4Ppjd7pgR56ySAZr7fiJBe?= =?us-ascii?Q?XkHTlRjFtHxp0SupcjBGXPHG4Uy5rQd2KiBsoxP?= =?us-ascii?Q?eeLdw7a6gl8ptDIMiJLqoZI6nZvDIKagCXlxfcr?= =?us-ascii?Q?PFECa+HYWmXdiqvn2v0V7YJUuyFfpM7sqoszc1Q?= =?us-ascii?Q?EXbH+p3fjBsQN5Bl5aCeGdqj3w=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: N6R576VKOPPBLCX4KNELY3GQPDMWXBY7 X-Message-ID-Hash: N6R576VKOPPBLCX4KNELY3GQPDMWXBY7 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:117989] [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). I'm still on my way back from Kaigi, so I haven't started working on this. But I had a quick chat with Matz, and it wasn't clear to him that we went with `frozen? -> true`, and he was clear he expects `frozen? -> false`. Also based on the reception I saw of the release notes in various places, it seems to have created quite a bit of confusion. So yes, this will introduce some false positive, which is unfortunate, but I'll definitely change the behavior soon. ---------------------------------------- Feature #20205: Enable `frozen_string_literal` by default https://bugs.ruby-lang.org/issues/20205#change-108413 * Author: byroot (Jean Boussier) * Status: Closed ---------------------------------------- ### 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/