Make `-release` more useful, deprecate `-target`, align with Scala 3 #9982

som-snytt · 2022-03-26T07:53:24Z

Why `-release`?

Use -release to specify the minimum JVM version that your code requires. This can be version 8 or higher, but is typically an LTS (Long Term Support) version such as -release 8, -release 11, or -release 17.

The compiler will compile your code with the Java standard library for the specified version, and it will output class files for that version (that is, that can only even be classloaded by that JVM version or higher).

Using -release allows you to decouple the JVM version on which your code is built from the minimum JVM version on which it runs. For example, you might specify -release 8 so your users are free to use 8, but you yourself can use 11 or 17 at build time (locally, or in CI).

What has changed?

-release already existed in earlier Scala versions, but it only controlled the Java standard library version, not the bytecode version (which was controlled by -target).

The old -target option is now deprecated, because -release now includes -target's behavior.

-java-output-version is now supported as an alias for -release.

Motivation

Improves ergonomics and avoids accidental misuse, since now only -release is needed, whereas before two flags were needed.

Aligns -releases behavior on Scala 2 with its behavior on Scala 3.

Fixes scala/bug#12543.

src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala

som-snytt · 2022-03-28T15:31:41Z

The test is missing. It said -release 8 which would have failed. It must be sitting on a different branch.

edit: #9981

som-snytt · 2022-03-28T19:43:22Z

I would like to take a moment to thank Travis for actually showing me the exception, looking at you, Jenkins.

Caused by: java.lang.NumberFormatException: For input string: "1.8"

oh, yeah.

som-snytt · 2022-03-28T20:05:50Z

oh right, that thing where CI settings differ from "home" settings even if I bootstrapped publishLocal etc etc etc.

[error] /home/travis/build/scala/scala/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala:103:38: match may not be exhaustive.

[error] It would fail on the following inputs: AnyScalaVersion, NoScalaVersion

[error]   val MaxTargetVersion = ScalaVersion(javaSpecVersion) match {

som-snytt · 2022-03-28T20:13:35Z

Re-rebuilt under 8 and confirmed -help shows

  -release:<release>           Compile for a version of the Java API and target class file. ([8])

and also compiled my 8-averse test file.

I wonder if "metaverse" is a contraction of "meta-averse"?

som-snytt · 2022-03-30T16:30:24Z

The glitch at 06d85a5

!!  1 - presentation/t12308                       [output differs]
% diff /home/jenkins/workspace/scala-2.13.x-validate-main/test/files/presentation/t12308.check /home/jenkins/workspace/scala-2.13.x-validate-main/test/files/presentation/t12308-presentation.log
@@ -46,5 +46,4 @@ askType at Foo.scala(4,37)
 [response] askTypeAt (4,37)
 1
 ================================================================================
-Problem(RangePosition(t12308/src/Foo.scala, 67, 67, 72),A try without a catch or finally is equivalent to putting its body in a block; no exceptions are handled.,1)
-Problem(RangePosition(t12308/src/Foo.scala, 109, 109, 114),A try without a catch or finally is equivalent to putting its body in a block; no exceptions are handled.,1)

som-snytt · 2022-03-30T16:41:26Z

That commit passes locally, so pushing rebase.

dwijnand · 2022-04-20T15:41:38Z

We might drop -scala-output-version, so let's wait on aligning things here.

som-snytt · 2022-04-20T16:02:36Z

Noting that the -scala-output-version is just an alias.

Edit: -java-output-version. The other option is not optionable on Scala 2.

som-snytt · 2022-04-22T18:01:44Z

Rebased and commented out the Scala 3 aliases so that there can be no objection to this PR.

som-snytt · 2022-09-01T00:29:11Z

@SethTisue also 🤞 Sorry I am so lame, I wish I had the gift for all the things you do.

SethTisue · 2022-09-01T00:31:31Z

I'm helpless without someone else's draft to revise! No joke.

som-snytt · 2022-09-01T00:32:19Z

OK here's a draft 🍺

xuwei-k · 2022-09-21T08:01:41Z

[2.13.9] Can't reference sun. package classes with -release option bug#12643 🤔

He-Pin · 2022-10-11T08:28:12Z

@som-snytt @SethTisue Will this been backport to 2.12.x? thanks.

som-snytt · 2022-10-11T08:36:13Z

@He-Pin Yes, but #10109

He-Pin · 2022-10-11T13:03:50Z

Thank you @som-snytt

Also changing sbt compiler option -target to -release as the former got deprecated with scala/scala#9982

rtyley · 2023-12-21T14:52:31Z

src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala

+        //target.value = setting.value  // this would trigger deprecation
+      }
+      .withAbbreviation("--release")
+      // .withAbbreviation("-java-output-version")


In Scala 3, -java-output-version is the preferred flag name (with the alias of -release still permitted) - would it be reasonable to uncomment this line, and allow Scala 2.13 to use -java-output-version as well?

I believe we'd accept a PR that did that — at least I can't think why not

Because the dotty project is really bad at choosing option names.

(to be clear: not suggesting we make it canonical in Scala 2, just an accepted alternative)

see also -Xunchecked-java-output-version. I didn't want to encourage them (the folks inventing these names). I came close to enabling them (the alt names) on this PR.

I believe we'd accept a PR that did that — at least I can't think why not

Thanks! Opened with #10654.

Because the dotty project is really bad at choosing option names.

This comment reminded me of my favourite video on software development, the 2012 talk by Andrew Dupont How to Argue About Code (sadly, as it's 'Not Yet Rated' on Vimeo, you have to login to view it in UK & EU, but at least after that there's no ads).

Regarding the option name, for myself, when I'm trying to help junior devs understand that if they want to run their code on Java 11, they need to specify -java-output-version 11, the conversation is a little easier than it is if I say -release 11. The first name, because it includes 'java', is more self-explanatory. The junior dev is aware of Scala and Java, but doesn't automatically realise that when Scala says -release, it's referring to a Java-related concern.

Following on from #9982 and discussion in https://github.com/scala/scala/pull/9982/files#r1434172490, this change enables `-java-output-version` as an alternative name for the `-release` flag in Scala 2, as in Scala 3 `-java-output-version` is the preferred flag name (see scala/scala3#14606 ), with the alias of `-release` still permitted. Correspondingly, `-Xunchecked-java-output-version` is also included as an alternative for `-target`, though note use of this flag is discouraged in favour of `-java-output-version`/`-release` for Java 9 and above.

…` instead of `-target` ### What changes were proposed in this pull request? This pr makes the following changes to allow Spark to build with `-release` instead of `-target`: 1. Use `MethodHandle` instead of direct calls to `sun.security.action.GetBooleanAction` and `sun.util.calendar.ZoneInfo`, because they are not `exports` APIs. 2. `Channels.newReader` is used instead of ``,StreamDecoder.forDecoder because `StreamDecoder.forDecoder` is also not `exports` APIs. ```java public static Reader newReader(ReadableByteChannel ch, CharsetDecoder dec, int minBufferCap) { Objects.requireNonNull(ch, "ch"); return StreamDecoder.forDecoder(ch, dec.reset(), minBufferCap); } ``` 3. Adjusted the import of `java.io._` in `yarn/Client.scala` to fix the compilation error: ``` Error: ] /home/runner/work/spark/spark/resource-managers/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala:20: object FileSystem is not a member of package java.io ``` 4. Replaced `-target` with `-release` in `pom.xml` and `SparkBuild.scala`, and removed the `-source` option, because using `-release` is sufficient. 5. Upgrade `scala-maven-plugin` from 4.7.1 to 4.8.1 to fix the error `[ERROR] -release cannot be less than -target` when executing `build/mvn clean install -DskipTests -Djava.version=21` ### Why are the changes needed? After Scala 2.13.9, the compile option `-target` has been deprecated, it is recommended to use `-release`: - scala/scala#9982 ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? Pass GitHub Actions ### Was this patch authored or co-authored using generative AI tooling? No Closes #45716 from LuciferYang/scala-maven-plugin-491. Authored-by: yangjie01 <yangjie01@baidu.com> Signed-off-by: Dongjoon Hyun <dhyun@apple.com>

…` instead of `-target` ### What changes were proposed in this pull request? This pr makes the following changes to allow Spark to build with `-release` instead of `-target`: 1. Use `MethodHandle` instead of direct calls to `sun.security.action.GetBooleanAction` and `sun.util.calendar.ZoneInfo`, because they are not `exports` APIs. 2. `Channels.newReader` is used instead of ``,StreamDecoder.forDecoder because `StreamDecoder.forDecoder` is also not `exports` APIs. ```java public static Reader newReader(ReadableByteChannel ch, CharsetDecoder dec, int minBufferCap) { Objects.requireNonNull(ch, "ch"); return StreamDecoder.forDecoder(ch, dec.reset(), minBufferCap); } ``` 3. Adjusted the import of `java.io._` in `yarn/Client.scala` to fix the compilation error: ``` Error: ] /home/runner/work/spark/spark/resource-managers/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala:20: object FileSystem is not a member of package java.io ``` 4. Replaced `-target` with `-release` in `pom.xml` and `SparkBuild.scala`, and removed the `-source` option, because using `-release` is sufficient. 5. Upgrade `scala-maven-plugin` from 4.7.1 to 4.8.1 to fix the error `[ERROR] -release cannot be less than -target` when executing `build/mvn clean install -DskipTests -Djava.version=21` ### Why are the changes needed? After Scala 2.13.9, the compile option `-target` has been deprecated, it is recommended to use `-release`: - scala/scala#9982 ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? Pass GitHub Actions ### Was this patch authored or co-authored using generative AI tooling? No Closes apache#45716 from LuciferYang/scala-maven-plugin-491. Authored-by: yangjie01 <yangjie01@baidu.com> Signed-off-by: Dongjoon Hyun <dhyun@apple.com>

scala-jenkins added this to the 2.13.9 milestone Mar 26, 2022

prolativ reviewed Mar 28, 2022

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som-snytt force-pushed the issue/12543 branch from f84aa78 to 4421fa8 Compare March 28, 2022 19:53

som-snytt force-pushed the issue/12543 branch from 4421fa8 to 2b3fb4c Compare March 28, 2022 20:14

SethTisue added the release-notes worth highlighting in next release notes label Mar 29, 2022

som-snytt force-pushed the issue/12543 branch from 2b3fb4c to 0a3a478 Compare March 29, 2022 17:53

som-snytt force-pushed the issue/12543 branch from 0a3a478 to 3b14c5d Compare March 30, 2022 16:41

This was referenced Mar 31, 2022

-Yimports documentation entry gives invalid format scala/docs.scala-lang#2155

Open

Update release and target options scala/docs.scala-lang#2014

Closed

armanbilge mentioned this pull request Apr 3, 2022

-release and friends renamed in Scala 3.1.2 typelevel/sbt-typelevel#205

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dwijnand marked this pull request as draft April 20, 2022 15:40

som-snytt mentioned this pull request Apr 22, 2022

Support JDK 19 #10001

Merged

som-snytt added 4 commits April 22, 2022 10:58

Align -release with Scala 3

3e6dbae

Use colon arg uniformly

db388d4

Add Scala 3 aliases, limit release, adjust target

cc60058

Revert Scala 3 aliases

4b3b050

som-snytt force-pushed the issue/12543 branch from 3b14c5d to 4b3b050 Compare April 22, 2022 17:59

som-snytt changed the title ~~Align -release with Scala 3~~ Make -release more useful, deprecate -target Apr 22, 2022

som-snytt marked this pull request as ready for review April 22, 2022 18:17

som-snytt mentioned this pull request May 8, 2022

Scalac can't generate 55(jvm11) bytecode version scala/bug#12588

Closed

SethTisue mentioned this pull request Sep 1, 2022

Always emit Java 8 bytecode on 2.12, regardless of -release; deprecate -target #10109

Merged

SethTisue changed the title ~~Make -release more useful, deprecate -target, align with Scala 3~~ Make -release more useful, deprecate -target, align with Scala 3 Sep 1, 2022

bjaglin mentioned this pull request Sep 20, 2022

scala 2.13.9 scalacenter/scalafix#1676

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This was referenced Sep 30, 2022

Is the documentation about the "-release" compiler flag correct? scala/docs.scala-lang#2569

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Explain why to use -target -release etc scala/docs.scala-lang#2308

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ybasket mentioned this pull request Sep 30, 2022

Update dependencies, add Scala Native support for circe integration, add jsoniter-scala integration gnieh/geo-scala#7

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vlushn mentioned this pull request Oct 3, 2022

bad option '-target:16' was ignored when compiling scala code with Scala3 library gradle/gradle#20180

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armanbilge mentioned this pull request Oct 8, 2022

Do not use deprecated -target option on 2.13.9+ typelevel/sbt-typelevel#385

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He-Pin mentioned this pull request Oct 11, 2022

=sbt Bump Scala version to 2.12.17 & 2.13.10, sbt to 1.7.2 akka/akka#31648

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LuciferYang mentioned this pull request Nov 10, 2022

[DONT'MERGE] Unify the version of scala-maven-plugin used by hadoop-2 and hadoop-3 profile apache/spark#38591

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ioannakok added a commit to guardian/frontend that referenced this pull request Nov 25, 2022

Upgrade to Scala 2.13.10

8405bfc

Also changing sbt compiler option -target to -release as the former got deprecated with scala/scala#9982

ioannakok mentioned this pull request Nov 25, 2022

Upgrade to Scala 2.13.10 guardian/frontend#25717

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dejan2609 mentioned this pull request Feb 21, 2023

Java/Scala build with no explicit toolchain: build fails with Gradle 8.0.1 / Scala 2.13 gradle/gradle#23962

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BalmungSan mentioned this pull request Mar 21, 2023

Update Scala versions apache/pekko#258

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amousset mentioned this pull request May 5, 2023

Fixes #22733: Build webapp on java 17 Normation/rudder#4791

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mdedetrich mentioned this pull request Jun 18, 2023

Use release 8 scalac flag to allow building on JDK11+ apache/pekko-http#187

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rtyley mentioned this pull request Aug 8, 2023

Use Java 11 guardian/typerighter#401

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rtyley mentioned this pull request Jan 8, 2024

Allow -java-output-version flag, matching Scala 3 #10654

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LuciferYang mentioned this pull request Mar 29, 2024

[SPARK-47645][BUILD][CORE][SQL][YARN] Make Spark build with -release instead of -target apache/spark#45716

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Make `-release` more useful, deprecate `-target`, align with Scala 3 #9982

Make `-release` more useful, deprecate `-target`, align with Scala 3 #9982

som-snytt commented Mar 26, 2022 •

edited by SethTisue

som-snytt commented Mar 28, 2022 •

edited

som-snytt commented Mar 28, 2022

som-snytt commented Mar 28, 2022

som-snytt commented Mar 28, 2022

som-snytt commented Mar 30, 2022

som-snytt commented Mar 30, 2022

dwijnand commented Apr 20, 2022

som-snytt commented Apr 20, 2022 •

edited

som-snytt commented Apr 22, 2022

som-snytt commented Sep 1, 2022

SethTisue commented Sep 1, 2022

som-snytt commented Sep 1, 2022

xuwei-k commented Sep 21, 2022

He-Pin commented Oct 11, 2022

som-snytt commented Oct 11, 2022

He-Pin commented Oct 11, 2022

rtyley Dec 21, 2023

SethTisue Jan 8, 2024

som-snytt Jan 8, 2024

SethTisue Jan 8, 2024

som-snytt Jan 8, 2024

rtyley Jan 8, 2024

Make -release more useful, deprecate -target, align with Scala 3 #9982

Make -release more useful, deprecate -target, align with Scala 3 #9982

Conversation

som-snytt commented Mar 26, 2022 • edited by SethTisue

Why -release?

What has changed?

Motivation

som-snytt commented Mar 28, 2022 • edited

som-snytt commented Mar 28, 2022

som-snytt commented Mar 28, 2022

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som-snytt commented Apr 20, 2022 • edited

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Make `-release` more useful, deprecate `-target`, align with Scala 3 #9982

Make `-release` more useful, deprecate `-target`, align with Scala 3 #9982

som-snytt commented Mar 26, 2022 •

edited by SethTisue

Why `-release`?

som-snytt commented Mar 28, 2022 •

edited

som-snytt commented Apr 20, 2022 •

edited