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 B37731F44D for ; Wed, 17 Apr 2024 11:08:00 +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=ZnyH4kCl; 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=PFJpid6H; dkim-atps=neutral Received: from nue.mailmanlists.eu (localhost [127.0.0.1]) by nue.mailmanlists.eu (Postfix) with ESMTP id 66F0C843CE; Wed, 17 Apr 2024 11:07:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ml.ruby-lang.org; s=mail; t=1713352071; bh=bIXSNnjzfYFLWE6p+6eUpr32fr1mBMInk0ZlXICjIbg=; 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=ZnyH4kClP4l2meUnHSD8pWbpFpsJTrP+jHxbcLA2keO+bm/koTIi0Pyw/KxvchrQ5 lBX65+6YJ9XphB+t++NtusDt4VNfM0DXpdEPdk2tUZ+OsclZxzoLr2mrbIWzyPlrm7 WTt3hSG2LImqM/N1CcIWWiGxLMHn2NXM5wW+hdTc= Received: from s.wrqvtbkv.outbound-mail.sendgrid.net (s.wrqvtbkv.outbound-mail.sendgrid.net [149.72.123.24]) by nue.mailmanlists.eu (Postfix) with ESMTPS id 110338439F for ; Wed, 17 Apr 2024 11:07:46 +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=PFJpid6H; 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=uJTftKEd0zGp0TjtfacGdZeMvlM9ezw0r5c22i7dWBo=; b=PFJpid6H+7ag+CCKmRoT5scdpCwq3APfk0fxdNqAhjq5DAGIwGu6odf3J8PkuzS2npAO kkmyx6eyDYM6IMfb9whdYBiXAJ2qHNyOpprY9LVteS/tbF9QJ523lQSStMMdkYic/Z7slB WAoqMnvKPFulYHd2USWss88heqDWeL0TeGpJGX7d7/IG4a2HkaRy1V3JPj6NHxL5cTQ3ky E8yfnq3ezqTcPqeu+kM7gITPzOHCsow13PgxAVG+5BZ0ZQGnvryD8ZhGe5TZ6tEyLwkY4m vZ+xtUyXpMsgdWw7wMnBPKHFfJfBK3GOOF4vO0JVcrp8FBlzjAk5xi6SgS93d9yw== Received: by filterdrecv-54566fd897-jsjjs with SMTP id filterdrecv-54566fd897-jsjjs-1-661FAD82-3 2024-04-17 11:07:46.106479232 +0000 UTC m=+393589.995495457 Received: from herokuapp.com (unknown) by geopod-ismtpd-34 (SG) with ESMTP id jis9I2ovTX-3G1fAuniKBQ for ; Wed, 17 Apr 2024 11:07:46.030 +0000 (UTC) Date: Wed, 17 Apr 2024 11:07:46 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 X-Redmine-Project: ruby-master X-Redmine-Issue-Tracker: Feature X-Redmine-Issue-Id: 15554 X-Redmine-Issue-Author: ko1 X-Redmine-Issue-Assignee: matz X-Redmine-Issue-Priority: Normal X-Redmine-Sender: ko1 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: 94157 X-SG-EID: =?us-ascii?Q?u001=2EbATEdfk2zDVGkqEmBpIo5H4n7Ev5v4PGlIEIJ8FEzfCkvwlGMFn=2FTmv+l?= =?us-ascii?Q?pwPr17bEITdo5x64lhfcVhbF8MZb5XqHMA4z3DR?= =?us-ascii?Q?vZAecv0oJnW5zLBHR+tM78eD0HIYWnnnIumuvl=2F?= =?us-ascii?Q?=2F4ABEM7clTscumxxngG2OOMKrepb0SIl+RJhmdh?= =?us-ascii?Q?1jrbV4OEW0cbzM00NX0dU8BrnJx1jHdh6A+=2FLmc?= =?us-ascii?Q?oh02Z+uVbc74C=2FSzpaMSOd4m7jrw5h6WtCoy+3o?= =?us-ascii?Q?F698feIB33cG8sH=2Ft16o35WKmA=3D=3D?= To: ruby-core@ml.ruby-lang.org X-Entity-ID: u001.I8uzylDtAfgbeCOeLBYDww== Message-ID-Hash: 4ZQYZP6TYU6ACSSFBKO3CDLA6PZXOAPG X-Message-ID-Hash: 4ZQYZP6TYU6ACSSFBKO3CDLA6PZXOAPG 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:117561] [Ruby master Feature#15554] warn/error passing a block to a method which never use a block List-Id: Ruby developers Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: "ko1 (Koichi Sasada) via ruby-core" Cc: "ko1 (Koichi Sasada)" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Issue #15554 has been updated by ko1 (Koichi Sasada). Matz hesitates to force to put `&_` (or other tricks) for duck typing methods, so I try to skip warning if a `foo` uses block, any other `foo` doesn't warn this warning even if it doesn't use a block. ```ruby class C0 def f = yield end class C1 < C0 def f = nil end [C0, C1].f{ block } # do not warn on both calls ``` https://github.com/ruby/ruby/pull/10559 ---------------------------------------- Feature #15554: warn/error passing a block to a method which never use a block https://bugs.ruby-lang.org/issues/15554#change-107960 * Author: ko1 (Koichi Sasada) * Status: Closed * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- # Abstract Warn or raise an ArgumentError if block is passed to a method which does not use a block. In other words, detect "block user methods" implicitly and only "block user methods" can accept a block. # Background Sometimes, we pass a block to a method which ignores the passed block accidentally. ``` def my_open(name) open(name) end # user hopes it works as Kernel#open which invokes a block with opened file. my_open(name){|f| important_work_with f } # but simply ignored... ``` To solve this issue, this feature request propose showing warnings or raising an exception on such case. Last developer's meeting, matz proposed `&nil` which declares this method never receive a block. It is explicit, but it is tough to add this `&nil` parameter declaration to all of methods (do you want to add it to `def []=(i, e, &nil)`?). (I agree `&nil` is valuable on some situations) # Spec ## Define "use a block" methods We need to define which method accepts a block and which method does not. * (1) method has a block parameter (`&b`) * (2) method body has `yield' * (3) method body has `super` (ZSUPER in internal terminology) or `super(...)` * (4) method body has singleton method (optional) (1) and (2) is very clear. I need to explain about (3) and (4). (3). `super` (ZSUPER) passes all parameters as arguments. So there is no surprise that which can accept `block`. However `super(...)` also passes a block if no explicit block passing (like `super(){}` or `super(&b)`) are written. I'm not sure we need to continue this strange specification, but to keep compatibility depending this spec, I add this rule. (4). surprisingly, the following code invoke a block: ``` def foo class << Object.new yield end end foo{ p :ok } #=> :ok ``` I'm also not sure we need to keep this spec, but to allow this spec, I added (4) rule. Strictly speaking, it is not required, but we don't keep the link from singleton class ISeq to lexical parent iseq now, so I added it. ## Exceptional cases A method called by `super` doesn`t warn warning even if this method doesn't use a block. The rule (3) can pass blocks easily and there are many methods don`t use a block. So my patch ignores callings by `super`. ## corner cases There are several cases to use block without (1)-(4) rules. ### `Proc.new/proc/lambda` without a block Now it was deprecated in r66772 (commit:9f1fb0a17febc59356d58cef5e98db61a3c03550). Related discussion: [Bug #15539] ### `block_given?` `block_given?` expects block, but I believe we use it with `yield` or a block parameter. If you know the usecase without them, please tell us. ### `yield` in `eval` We can't know `yield` (or (3), (4) rule) in an `eval` evaluating string at calling time. ``` def foo eval('yield`) end foo{} # at calling time, # we can't know the method foo can accept a block or not. ``` So I added a warning to use `yield` in `eval` like that: `test.rb:4: warning: use yield in eval will not be supported in Ruby 3.` Workaround is use a block parameter explicitly. ``` def foo &b eval('b.call') end foo{ p :ok } ``` # Implementation Strategy is: * [compile time] introduce `iseq::has_yield` field and check it if the iseq (or child iseq) contains `yield` (or something) * [calling time] if block is given, check `iseq::has_yield` flag and show warning (or raise an exception) https://gist.github.com/ko1/c9148ad0224bf5befa3cc76ed2220c0b On this patch, now it raises an error to make it easy to detect. It is easy to switch to show the warning. # Evaluation and discussion I tried to avoid ruby's tests. https://gist.github.com/ko1/37483e7940cdc4390bf8eb0001883786 Here is a patch. There are several patterns to avoid warnings. ## tests for `block_given?`, `Proc.new` (and similar) without block Add a dummy block parameter. It is test-specific issue. ## empty `each` Some tests add `each` methods do not `yield`, like: `def each; end`. Maybe test-specific issue, and adding a dummy block parameter. ## Subtyping / duck typing https://github.com/ruby/ruby/blob/c01a5ee85e2d6a7128cccafb143bfa694284ca87/lib/optparse.rb#L698 This `parse` method doesn't use `yield`, but other sub-type's `parse` methods use. ## `super` with `new` method https://gist.github.com/ko1/37483e7940cdc4390bf8eb0001883786#file-tests-patch-L61 This method override `Class#new` method and introduce a hook with block (yield a block in this hook code). https://github.com/ruby/ruby/blob/trunk/lib/rubygems/package/tar_writer.rb#L81 In this method, call `super` and it also passing a block. However, called `initialize` doesn't use a block. ## Change robustness This change reduce robustness for API change. `Delegator` requires to support `__getobj__` for client classes. Now `__getobj__` should accept block but most of `__getobj__` clients do not call given block. https://github.com/ruby/ruby/blob/trunk/lib/delegate.rb#L80 This is because of delegator.rb's API change. https://gist.github.com/ko1/37483e7940cdc4390bf8eb0001883786#file-tests-patch-L86 Nobu says calling block is not required (ignoring a block is no problem) so it is not a bug for delegator client classes. ## Found issues. ``` [ 2945/20449] Rinda::TestRingServer#test_do_reply = 0.00 s 1) Error: Rinda::TestRingServer#test_do_reply: ArgumentError: passing block to the method "with_timeout" (defined at /home/ko1/src/ruby/trunk/test/rinda/test_rinda.rb:787) is never used. /home/ko1/src/ruby/trunk/test/rinda/test_rinda.rb:635:in `test_do_reply' [ 2946/20449] Rinda::TestRingServer#test_do_reply_local = 0.00 s 2) Error: Rinda::TestRingServer#test_do_reply_local: ArgumentError: passing block to the method "with_timeout" (defined at /home/ko1/src/ruby/trunk/test/rinda/test_rinda.rb:787) is never used. /home/ko1/src/ruby/trunk/test/rinda/test_rinda.rb:657:in `test_do_reply_local' [10024/20449] TestGemRequestSetGemDependencyAPI#test_platform_mswin = 0.01 s 3) Error: TestGemRequestSetGemDependencyAPI#test_platform_mswin: ArgumentError: passing block to the method "util_set_arch" (defined at /home/ko1/src/ruby/trunk/lib/rubygems/test_case.rb:1053) is never used. /home/ko1/src/ruby/trunk/test/rubygems/test_gem_request_set_gem_dependency_api.rb:655:in `test_platform_mswin' [10025/20449] TestGemRequestSetGemDependencyAPI#test_platforms = 0.01 s 4) Error: TestGemRequestSetGemDependencyAPI#test_platforms: ArgumentError: passing block to the method "util_set_arch" (defined at /home/ko1/src/ruby/trunk/lib/rubygems/test_case.rb:1053) is never used. /home/ko1/src/ruby/trunk/test/rubygems/test_gem_request_set_gem_dependency_api.rb:711:in `test_platforms' ``` These 4 detection show the problem. `with_timeout` method (used in Rinda test) and `util_set_arch` method (used in Rubygems test) simply ignore the given block. So these tests are simply ignored. I reported them. (https://github.com/rubygems/rubygems/issues/2601) ## raise an error or show a warning? At least, Ruby 2.7 should show warning for this kind of violation with `-w`. How about for Ruby3? -- 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/