Scala 3 遷移指南

編譯器選項查詢表

此表格列出 Scala 2.13 編譯器選項及其在 Scala 3 中的等效選項。有些選項具有跨版本支援，例如 -Vprint。其他選項有近似的等效選項，但名稱不同。許多 Scala 2 選項在 Scala 3 中沒有等效選項，例如用於除錯 Scala 2 巨集的選項。

編譯器選項顯示為說明輸出 scalac -help、scalac -X 等所顯示的內容。這裡顯示了一些別名，但大多數較舊的別名，例如 -Xprint 表示 -Vprint，或 -Ytyper-debug 表示 -Vtyper，都以最新的名稱列出。

選項群組 -V 和 -W 在 Scala 2.13 中引入，用於要求額外診斷輸出的「詳細」選項和要求額外檢查（可能表示程式碼錯誤，也可能不表示錯誤）的「警告」。-Werror 將警告提升為錯誤，而 -Wconf 允許精確控制警告，方法是忽略警告或將其視為錯誤。遷移到 Scala 3 時，-Wconf 的組態字串可能需要調整，因為組態語法和它比對的錯誤訊息不同。

狀態	意義
	Scala 3 中提供。
`<new-name>`	已重新命名為 `<new-name>`。
	尚未提供，但可能在稍後新增。

目前的比較基於 Scala 2.13.10 和 3.3.0。

標準設定

2.13.x	3.3.x
`-Dproperty=value`
`-J<flag>`
`-P:<plugin>:<opt>`
`-V`
`-W`
`-X`
`-Y`
`-bootclasspath`
`-classpath`
`-d`
`-dependencyfile`
`-deprecation`
`-encoding`
`-explaintypes`	`-explain-types`
`-extdirs`
`-feature`
`-g`
`-help`
`-javabootclasspath`
`-javaextdirs`
`-language`
`-no-specialization`
`-nobootcp`
`-nowarn`
`-opt`
`-opt-inline-from`
`-opt-warnings`
`-optimize`
`-print`
`-release`
`-rootdir`
`-sourcepath`
`-target`	`-Xtarget`
`-toolcp`
`-unchecked`
`-uniqid`
`-usejavacp`
`-usemanifestc`
`-verbose`
`-version`

詳細設定

2.13.x	3.3.x
`-Vbrowse:<phases>`
`-Vclasspath`	`-Ylog-classpath`
`-Vdebug`	`-Ydebug`
`-Vdebug-tasty`
`-Vdebug-type-error`
`-Vdoc`
`-Vfree-terms`
`-Vfree-types`
`-Vhot-statistics`
`-Vide`
`-Vimplicit-conversions`
`-Vimplicits`
`-Vimplicits-max-refined`
`-Vimplicits-verbose-tree`
`-Vinline <package/Class.method>`
`-Vlog:<phases>`	`-Ylog:<phases>`
`-Vmacro`
`-Vmacro-lite`
`-Vopt <package/Class.method>`
`-Vpatmat`
`-Vphases`
`-Vpos`
`-Vprint:<phases>`
`-Vprint-args <file>`
`-Vprint-pos`	`-Yprint-pos`
`-Vprint-types`	`-Xprint-types`
`-Vquasiquote`
`-Vreflective-calls`
`-Vreify`
`-Vshow:<phases>`
`-Vshow-class <class>`
`-Vshow-member-pos <output style>`
`-Vshow-object <object>`
`-Vshow-symkinds`
`-Vshow-symowners`
`-Vstatistics <phases>`
`-Vsymbols`
`-Vtype-diffs`
`-Vtyper`

警告設定

2.13.x	3.3.x
`-Wconf`
`-Wdead-code`
`-Werror`
`-Wextra-implicit`
`-Wmacros:<mode>`
`-Wnonunit-if`
`-Wnonunit-statement`
`-Wnumeric-widen`
`-Woctal-literal`
`-Wopt`
`-Wperformance`
`-Wself-implicit`
`-Wunused:<warnings>`
`-Wvalue-discard`

進階設定

2.13.x	3.3.x
`-Xasync`
`-Xcheckinit`	`-Ysafe-init`
`-Xdev`
`-Xdisable-assertions`
`-Xelide-below`
`-Xexperimental`
`-Xfuture`
`-Xgenerate-phase-graph`
`-Xjline`
`-Xlint:deprecation`	`-deprecation`
`-Xlint:<warnings>`
`-Xmacro-settings`
`-Xmain-class`
`-Xmaxerrs`
`-Xmaxwarns`
`-Xmigration`
`-Xmixin-force-forwarders`
`-Xno-forwarders`
`-Xno-patmat-analysis`
`-Xnon-strict-patmat-analysis`
`-Xnojline`
`-Xplugin`
`-Xplugin-disable`
`-Xplugin-list`
`-Xplugin-require`
`-Xpluginsdir`
`-Xprompt`
`-Xreporter`
`-Xresident`
`-Xscript`
`-Xsource`	`-source`
`-Xsource-reader`
`-Xverify`	`-Xverify-signatures`
`-Xxml`

私人設定

2.13.x	3.0.x
`-Ybackend-parallelism`
`-Ybackend-worker-queue`
`-Ybreak-cycles`
`-Ycache-macro-class-loader`
`-Ycache-plugin-class-loader`
`-Ycheck`
`-Ycompact-trees`
`-Ydelambdafy`
`-Ydump-classes`
`-Ygen-asmp`
`-Yimports`
`-Yissue-debug`
`-Yjar-compression-level`
`-YjarFactory`
`-Ymacro-annotations`
`-Ymacro-classpath`
`-Ymacro-expand`
`-Ymacro-global-fresh-names`
`-Yno-completion`
`-Yno-flat-classpath-cache`
`-Yno-generic-signatures`
`-Yno-imports`
`-Yno-predef`
`-Yopt-inline-heuristics`
`-Ypatmat-exhaust-depth`
`-Ypresentation-any-thread`
`-Ypresentation-debug`
`-Ypresentation-delay`
`-Ypresentation-locate-source-file`
`-Ypresentation-log`
`-Ypresentation-replay`
`-Ypresentation-strict`
`-Ypresentation-verbose`
`-Yprint-trees`
`-Yprofile-destination`
`-Yprofile-enabled`
`-Yprofile-external-tool`
`-Yprofile-run-gc`
`-Yprofile-trace`
`-Yrangepos`
`-Yrecursion`
`-Yreify-copypaste`
`-Yrepl-class-based`
`-Yrepl-outdir`
`-Yrepl-use-magic-imports`
`-Yresolve-term-conflict`
`-Yscala3-implicit-resolution`
`-Yscriptrunner`
`-Yskip`
`-Ystop-after`
`-Ystop-before`
`-Ytasty-no-annotations`
`-Ytasty-reader`
`-Ytrack-dependencies`
`-Yvalidate-pos`

編譯器外掛程式

一些有用的 Scala 2.13 編譯器外掛程式現在已發布到編譯器中。你可以使用一些新的原生選項來啟用和設定它們。

Scala.js

2.13.x	3.0.x
`-Xplugin:scalajs-compiler_<version>.jar`	`-scalajs`
`-P:scalajs:genStaticForwardersForNonTopLevelObjects`	`-scalajs-genStaticForwardersForNonTopLevelObjects`
`-P:scalajs:mapSourceURI`	`-scalajs-mapSourceURI`

SemanticDB

2.13.x	3.0.x
`-Xplugin:semanticdb-scalac_<version>.jar`	`-Xsemanticdb`
`-P:semanticdb:targetroot:<path>`	`-semanticdb-target:<path>`

Kind-Projector

2.13.x	3.0.x
`-Xplugin:kind-projector_<version>.jar`	`-Ykind-projector`