By Alvin Alexander. Last updated: January 26, 2021
Just so I can find this again easily when I need it, here’s a copy of the ScalaSettings.scala file from the Scala 3 (nee Dotty) project:
package dotty.tools.dotc
package config
import dotty.tools.dotc.core.Contexts._
import dotty.tools.io.{ Directory, PlainDirectory, AbstractFile, JDK9Reflectors }
import PathResolver.Defaults
import rewrites.Rewrites
import Settings.Setting
/** Settings shared by compiler and scala3doc */
trait CommonScalaSettings { self: Settings.SettingGroup =>
protected def defaultClasspath: String = sys.env.getOrElse("CLASSPATH", ".")
/** Path related settings */
val bootclasspath: Setting[String] = PathSetting("-bootclasspath", "Override location of bootstrap class files.", Defaults.scalaBootClassPath, aliases = List("--boot-class-path"))
val extdirs: Setting[String] = PathSetting("-extdirs", "Override location of installed extensions.", Defaults.scalaExtDirs, aliases = List("--extension-directories"))
val javabootclasspath: Setting[String] = PathSetting("-javabootclasspath", "Override java boot classpath.", Defaults.javaBootClassPath, aliases = List("--java-boot-class-path"))
val javaextdirs: Setting[String] = PathSetting("-javaextdirs", "Override java extdirs classpath.", Defaults.javaExtDirs, aliases = List("--java-extension-directories"))
val sourcepath: Setting[String] = PathSetting("-sourcepath", "Specify location(s) of source files.", Defaults.scalaSourcePath, aliases = List("--source-path"))
val sourceroot: Setting[String] = PathSetting("-sourceroot", "Specify workspace root directory.", ".")
val classpath: Setting[String] = PathSetting("-classpath", "Specify where to find user class files.", defaultClasspath, aliases = List("-cp", "--class-path"))
val outputDir: Setting[AbstractFile] = OutputSetting("-d", "directory|jar", "Destination for generated classfiles.",
new PlainDirectory(Directory(".")))
val color: Setting[String] = ChoiceSetting("-color", "mode", "Colored output", List("always", "never"/*, "auto"*/), "always"/* "auto"*/, aliases = List("--color"))
val verbose: Setting[Boolean] = BooleanSetting("-verbose", "Output messages about what the compiler is doing.", aliases = List("--verbose"))
val version: Setting[Boolean] = BooleanSetting("-version", "Print product version and exit.", aliases = List("--version"))
val pageWidth: Setting[Int] = IntSetting("-pagewidth", "Set page width", 80, aliases = List("--page-width"))
val silentWarnings: Setting[Boolean] = BooleanSetting("-nowarn", "Silence all warnings.", aliases = List("--no-warnings"))
/** Other settings */
val encoding: Setting[String] = StringSetting("-encoding", "encoding", "Specify character encoding used by source files.", Properties.sourceEncoding, aliases = List("--encoding"))
val usejavacp: Setting[Boolean] = BooleanSetting("-usejavacp", "Utilize the java.class.path in classpath resolution.", aliases = List("--use-java-class-path"))
/** Plugin-related setting */
val plugin: Setting[List[String]] = MultiStringSetting ("-Xplugin", "paths", "Load a plugin from each classpath.")
val disable: Setting[List[String]] = MultiStringSetting ("-Xplugin-disable", "plugin", "Disable plugins by name.")
val require: Setting[List[String]] = MultiStringSetting ("-Xplugin-require", "plugin", "Abort if a named plugin is not loaded.")
val showPlugins: Setting[Boolean] = BooleanSetting ("-Xplugin-list", "Print a synopsis of loaded plugins.")
val pluginsDir: Setting[String] = StringSetting ("-Xpluginsdir", "path", "Path to search for plugin archives.", Defaults.scalaPluginPath)
val pluginOptions: Setting[List[String]] = MultiStringSetting ("-P", "plugin:opt", "Pass an option to a plugin, e.g. -P:<plugin>:<opt>")
/** Doctool specific settings */
val siteRoot: Setting[String] = StringSetting(
"-siteroot",
"site root",
"A directory containing static files from which to generate documentation.",
"./docs"
)
val projectName: Setting[String] = StringSetting (
"-project",
"project title",
"The name of the project.",
""
)
val projectVersion: Setting[String] = StringSetting (
"-project-version",
"project version",
"The current version of your project.",
""
)
val projectLogo: Setting[String] = StringSetting(
"-project-logo",
"project logo filename",
"The file that contains the project's logo (in /images).",
""
)
}
class ScalaSettings extends Settings.SettingGroup with CommonScalaSettings {
private val minTargetVersion = 8
private val maxTargetVersion = 15
private def supportedTargetVersions: List[String] =
(minTargetVersion to maxTargetVersion).toList.map(_.toString)
protected def supportedReleaseVersions: List[String] =
if scala.util.Properties.isJavaAtLeast("9") then
val jdkVersion = JDK9Reflectors.runtimeVersionMajor(JDK9Reflectors.runtimeVersion()).intValue()
val maxVersion = Math.min(jdkVersion, maxTargetVersion)
(minTargetVersion to maxVersion).toList.map(_.toString)
else List()
/** Path related settings */
val semanticdbTarget: Setting[String] = PathSetting("-semanticdb-target", "Specify an alternative output directory for SemanticDB files.", "")
val deprecation: Setting[Boolean] = BooleanSetting("-deprecation", "Emit warning and location for usages of deprecated APIs.", aliases = List("--deprecation"))
val explainTypes: Setting[Boolean] = BooleanSetting("-explain-types", "Explain type errors in more detail.", aliases = List("--explain-types"))
val explain: Setting[Boolean] = BooleanSetting("-explain", "Explain errors in more detail.", aliases = List("--explain"))
val feature: Setting[Boolean] = BooleanSetting("-feature", "Emit warning and location for usages of features that should be imported explicitly.", aliases = List("--feature"))
val help: Setting[Boolean] = BooleanSetting("-help", "Print a synopsis of standard options.", aliases = List("--help"))
val release: Setting[String] = ChoiceSetting("-release", "release", "Compile code with classes specific to the given version of the Java platform available on the classpath and emit bytecode for this version.", supportedReleaseVersions, "", aliases = List("--release"))
val source: Setting[String] = ChoiceSetting("-source", "source version", "source version", List("3.0", "3.1", "3.0-migration", "3.1-migration"), "3.0", aliases = List("--source"))
val scalajs: Setting[Boolean] = BooleanSetting("-scalajs", "Compile in Scala.js mode (requires scalajs-library.jar on the classpath).", aliases = List("--scalajs"))
val unchecked: Setting[Boolean] = BooleanSetting("-unchecked", "Enable additional warnings where generated code depends on assumptions.", aliases = List("--unchecked"))
val uniqid: Setting[Boolean] = BooleanSetting("-uniqid", "Uniquely tag all identifiers in debugging output.", aliases = List("--unique-id"))
val language: Setting[List[String]] = MultiStringSetting("-language", "feature", "Enable one or more language features.", aliases = List("--language"))
val rewrite: Setting[Option[Rewrites]] = OptionSetting[Rewrites]("-rewrite", "When used in conjunction with a `...-migration` source version, rewrites sources to migrate to new version.", aliases = List("--rewrite"))
val fromTasty: Setting[Boolean] = BooleanSetting("-from-tasty", "Compile classes from tasty files. The arguments are .tasty or .jar files.", aliases = List("--from-tasty"))
val newSyntax: Setting[Boolean] = BooleanSetting("-new-syntax", "Require `then` and `do` in control expressions.")
val oldSyntax: Setting[Boolean] = BooleanSetting("-old-syntax", "Require `(...)` around conditions.")
val indent: Setting[Boolean] = BooleanSetting("-indent", "Together with -rewrite, remove {...} syntax when possible due to significant indentation.")
val noindent: Setting[Boolean] = BooleanSetting("-noindent", "Require classical {...} syntax, indentation is not significant.")
val YindentColons: Setting[Boolean] = BooleanSetting("-Yindent-colons", "Allow colons at ends-of-lines to start indentation blocks.")
/** Decompiler settings */
val printTasty: Setting[Boolean] = BooleanSetting("-print-tasty", "Prints the raw tasty.", aliases = List("--print-tasty"))
val printLines: Setting[Boolean] = BooleanSetting("-print-lines", "Show source code line numbers.", aliases = List("--print-lines"))
/** Scala.js-related settings */
val scalajsGenStaticForwardersForNonTopLevelObjects: Setting[Boolean] = BooleanSetting("-scalajs-genStaticForwardersForNonTopLevelObjects", "Generate static forwarders even for non-top-level objects (Scala.js only)")
val scalajsMapSourceURI: Setting[List[String]] = MultiStringSetting("-scalajs-mapSourceURI", "uri1[->uri2]", "rebases source URIs from uri1 to uri2 (or to a relative URI) for source maps (Scala.js only)")
/** -X "Advanced" settings */
val Xhelp: Setting[Boolean] = BooleanSetting("-X", "Print a synopsis of advanced options.")
val XnoForwarders: Setting[Boolean] = BooleanSetting("-Xno-forwarders", "Do not generate static forwarders in mirror classes.")
val XmaxInlines: Setting[Int] = IntSetting("-Xmax-inlines", "Maximal number of successive inlines.", 32)
val XmaxInlinedTrees: Setting[Int] = IntSetting("-Xmax-inlined-trees", "Maximal number of inlined trees.", 2_000_000)
val Xmigration: Setting[ScalaVersion] = VersionSetting("-Xmigration", "Warn about constructs whose behavior may have changed since version.")
val Xprint: Setting[List[String]] = PhasesSetting("-Xprint", "Print out program after")
val XprintTypes: Setting[Boolean] = BooleanSetting("-Xprint-types", "Print tree types (debugging option).")
val XprintDiff: Setting[Boolean] = BooleanSetting("-Xprint-diff", "Print changed parts of the tree since last print.")
val XprintDiffDel: Setting[Boolean] = BooleanSetting("-Xprint-diff-del", "Print changed parts of the tree since last print including deleted parts.")
val XprintInline: Setting[Boolean] = BooleanSetting("-Xprint-inline", "Show where inlined code comes from.")
val XprintSuspension: Setting[Boolean] = BooleanSetting("-Xprint-suspension", "Show when code is suspended until macros are compiled.")
val Xprompt: Setting[Boolean] = BooleanSetting("-Xprompt", "Display a prompt after each error (debugging option).")
val XshowPhases: Setting[Boolean] = BooleanSetting("-Xshow-phases", "Print all compiler phases.")
val XreplDisableDisplay: Setting[Boolean] = BooleanSetting("-Xrepl-disable-display", "Do not display definitions in REPL.")
val XfatalWarnings: Setting[Boolean] = BooleanSetting("-Xfatal-warnings", "Fail the compilation if there are any warnings.")
val XverifySignatures: Setting[Boolean] = BooleanSetting("-Xverify-signatures", "Verify generic signatures in generated bytecode.")
val XignoreScala2Macros: Setting[Boolean] = BooleanSetting("-Xignore-scala2-macros", "Ignore errors when compiling code that calls Scala2 macros, these will fail at runtime.")
val XimportSuggestionTimeout: Setting[Int] = IntSetting("-Ximport-suggestion-timeout", "Timeout (in ms) for searching for import suggestions when errors are reported.", 8000)
val Xsemanticdb: Setting[Boolean] = BooleanSetting("-Xsemanticdb", "Store information in SemanticDB.", aliases = List("-Ysemanticdb"))
val Xtarget: Setting[String] = ChoiceSetting("-Xtarget", "target", "Emit bytecode for the specified version of the Java platform. This might produce bytecode that will break at runtime. When on JDK 9+, consider -release as a safer alternative.", supportedTargetVersions, "", aliases = List("--Xtarget"))
val XmixinForceForwarders = ChoiceSetting(
name = "-Xmixin-force-forwarders",
helpArg = "mode",
descr = "Generate forwarder methods in classes inhering concrete methods from traits.",
choices = List("true", "junit", "false"),
default = "true")
object mixinForwarderChoices {
def isTruthy(using Context) = XmixinForceForwarders.value == "true"
def isAtLeastJunit(using Context) = isTruthy || XmixinForceForwarders.value == "junit"
}
/** -Y "Private" settings */
val Yhelp: Setting[Boolean] = BooleanSetting("-Y", "Print a synopsis of private options.")
val Ycheck: Setting[List[String]] = PhasesSetting("-Ycheck", "Check the tree at the end of")
val YcheckMods: Setting[Boolean] = BooleanSetting("-Ycheck-mods", "Check that symbols and their defining trees have modifiers in sync.")
val Ydebug: Setting[Boolean] = BooleanSetting("-Ydebug", "Increase the quantity of debugging output.")
val YdebugTrace: Setting[Boolean] = BooleanSetting("-Ydebug-trace", "Trace core operations.")
val YdebugFlags: Setting[Boolean] = BooleanSetting("-Ydebug-flags", "Print all flags of definitions.")
val YdebugMissingRefs: Setting[Boolean] = BooleanSetting("-Ydebug-missing-refs", "Print a stacktrace when a required symbol is missing.")
val YdebugNames: Setting[Boolean] = BooleanSetting("-Ydebug-names", "Show internal representation of names.")
val YdebugPos: Setting[Boolean] = BooleanSetting("-Ydebug-pos", "Show full source positions including spans.")
val YdebugTreeWithId: Setting[Int] = IntSetting("-Ydebug-tree-with-id", "Print the stack trace when the tree with the given id is created.", Int.MinValue)
val YdebugTypeError: Setting[Boolean] = BooleanSetting("-Ydebug-type-error", "Print the stack trace when a TypeError is caught", false)
val YdebugError: Setting[Boolean] = BooleanSetting("-Ydebug-error", "Print the stack trace when any error is caught.", false)
val YtermConflict: Setting[String] = ChoiceSetting("-Yresolve-term-conflict", "strategy", "Resolve term conflicts", List("package", "object", "error"), "error")
val Ylog: Setting[List[String]] = PhasesSetting("-Ylog", "Log operations during")
val YlogClasspath: Setting[Boolean] = BooleanSetting("-Ylog-classpath", "Output information about what classpath is being applied.")
val YdisableFlatCpCaching: Setting[Boolean] = BooleanSetting("-YdisableFlatCpCaching", "Do not cache flat classpath representation of classpath elements from jars across compiler instances.")
val Yscala2Unpickler: Setting[String] = StringSetting("-Yscala2-unpickler", "", "Control where we may get Scala 2 symbols from. This is either \"always\", \"never\", or a classpath.", "always")
val YnoImports: Setting[Boolean] = BooleanSetting("-Yno-imports", "Compile without importing scala.*, java.lang.*, or Predef.")
val YnoGenericSig: Setting[Boolean] = BooleanSetting("-Yno-generic-signatures", "Suppress generation of generic signatures for Java.")
val YnoPredef: Setting[Boolean] = BooleanSetting("-Yno-predef", "Compile without importing Predef.")
val Yskip: Setting[List[String]] = PhasesSetting("-Yskip", "Skip")
val Ydumpclasses: Setting[String] = StringSetting("-Ydump-classes", "dir", "Dump the generated bytecode to .class files (useful for reflective compilation that utilizes in-memory classloaders).", "")
val YstopAfter: Setting[List[String]] = PhasesSetting("-Ystop-after", "Stop after", aliases = List("-stop")) // backward compat
val YstopBefore: Setting[List[String]] = PhasesSetting("-Ystop-before", "Stop before") // stop before erasure as long as we have not debugged it fully
val YshowSuppressedErrors: Setting[Boolean] = BooleanSetting("-Yshow-suppressed-errors", "Also show follow-on errors and warnings that are normally suppressed.")
val YdetailedStats: Setting[Boolean] = BooleanSetting("-Ydetailed-stats", "Show detailed internal compiler stats (needs Stats.enabled to be set to true).")
val YkindProjector: Setting[Boolean] = BooleanSetting("-Ykind-projector", "Allow `*` as wildcard to be compatible with kind projector.")
val YprintPos: Setting[Boolean] = BooleanSetting("-Yprint-pos", "Show tree positions.")
val YprintPosSyms: Setting[Boolean] = BooleanSetting("-Yprint-pos-syms", "Show symbol definitions positions.")
val YnoDeepSubtypes: Setting[Boolean] = BooleanSetting("-Yno-deep-subtypes", "Throw an exception on deep subtyping call stacks.")
val YnoPatmatOpt: Setting[Boolean] = BooleanSetting("-Yno-patmat-opt", "Disable all pattern matching optimizations.")
val YplainPrinter: Setting[Boolean] = BooleanSetting("-Yplain-printer", "Pretty-print using a plain printer.")
val YprintSyms: Setting[Boolean] = BooleanSetting("-Yprint-syms", "When printing trees print info in symbols instead of corresponding info in trees.")
val YprintDebug: Setting[Boolean] = BooleanSetting("-Yprint-debug", "When printing trees, print some extra information useful for debugging.")
val YprintDebugOwners: Setting[Boolean] = BooleanSetting("-Yprint-debug-owners", "When printing trees, print owners of definitions.")
val YshowPrintErrors: Setting[Boolean] = BooleanSetting("-Yshow-print-errors", "Don't suppress exceptions thrown during tree printing.")
val YtestPickler: Setting[Boolean] = BooleanSetting("-Ytest-pickler", "Self-test for pickling functionality; should be used with -Ystop-after:pickler.")
val YcheckReentrant: Setting[Boolean] = BooleanSetting("-Ycheck-reentrant", "Check that compiled program does not contain vars that can be accessed from a global root.")
val YdropComments: Setting[Boolean] = BooleanSetting("-Ydrop-comments", "Drop comments when scanning source files.")
val YcookComments: Setting[Boolean] = BooleanSetting("-Ycook-comments", "Cook the comments (type check `@usecase`, etc.)")
val YforceSbtPhases: Setting[Boolean] = BooleanSetting("-Yforce-sbt-phases", "Run the phases used by sbt for incremental compilation (ExtractDependencies and ExtractAPI) even if the compiler is ran outside of sbt, for debugging.")
val YdumpSbtInc: Setting[Boolean] = BooleanSetting("-Ydump-sbt-inc", "For every compiled foo.scala, output the API representation and dependencies used for sbt incremental compilation in foo.inc, implies -Yforce-sbt-phases.")
val YcheckAllPatmat: Setting[Boolean] = BooleanSetting("-Ycheck-all-patmat", "Check exhaustivity and redundancy of all pattern matching (used for testing the algorithm).")
val YretainTrees: Setting[Boolean] = BooleanSetting("-Yretain-trees", "Retain trees for top-level classes, accessible from ClassSymbol#tree")
val YshowTreeIds: Setting[Boolean] = BooleanSetting("-Yshow-tree-ids", "Uniquely tag all tree nodes in debugging output.")
val YfromTastyIgnoreList: Setting[List[String]] = MultiStringSetting("-Yfrom-tasty-ignore-list", "file", "List of `tasty` files in jar files that will not be loaded when using -from-tasty")
val YprofileEnabled: Setting[Boolean] = BooleanSetting("-Yprofile-enabled", "Enable profiling.")
val YprofileDestination: Setting[String] = StringSetting("-Yprofile-destination", "file", "Where to send profiling output - specify a file, default is to the console.", "")
//.withPostSetHook( _ => YprofileEnabled.value = true )
val YprofileExternalTool: Setting[List[String]] = PhasesSetting("-Yprofile-external-tool", "Enable profiling for a phase using an external tool hook. Generally only useful for a single phase.", "typer")
//.withPostSetHook( _ => YprofileEnabled.value = true )
val YprofileRunGcBetweenPhases: Setting[List[String]] = PhasesSetting("-Yprofile-run-gc", "Run a GC between phases - this allows heap size to be accurate at the expense of more time. Specify a list of phases, or *", "_")
//.withPostSetHook( _ => YprofileEnabled.value = true )
// Extremely experimental language features
val YnoKindPolymorphism: Setting[Boolean] = BooleanSetting("-Yno-kind-polymorphism", "Disable kind polymorphism.")
val YexplicitNulls: Setting[Boolean] = BooleanSetting("-Yexplicit-nulls", "Make reference types non-nullable. Nullable types can be expressed with unions: e.g. String|Null.")
val YerasedTerms: Setting[Boolean] = BooleanSetting("-Yerased-terms", "Allows the use of erased terms.")
val YcheckInit: Setting[Boolean] = BooleanSetting("-Ycheck-init", "Check initialization of objects")
val YrequireTargetName: Setting[Boolean] = BooleanSetting("-Yrequire-targetName", "Warn if an operator is defined without a @targetName annotation")
val YunsoundMatchTypes: Setting[Boolean] = BooleanSetting("-Yunsound-match-types", "Use unsound match type reduction algorithm.")
/** Area-specific debug output */
val YexplainLowlevel: Setting[Boolean] = BooleanSetting("-Yexplain-lowlevel", "When explaining type errors, show types at a lower level.")
val YnoDoubleBindings: Setting[Boolean] = BooleanSetting("-Yno-double-bindings", "Assert no namedtype is bound twice (should be enabled only if program is error-free).")
val YshowVarBounds: Setting[Boolean] = BooleanSetting("-Yshow-var-bounds", "Print type variables with their bounds.")
val YnoDecodeStacktraces: Setting[Boolean] = BooleanSetting("-Yno-decode-stacktraces", "Show raw StackOverflow stacktraces, instead of decoding them into triggering operations.")
val Yinstrument: Setting[Boolean] = BooleanSetting("-Yinstrument", "Add instrumentation code that counts allocations and closure creations.")
val YinstrumentDefs: Setting[Boolean] = BooleanSetting("-Yinstrument-defs", "Add instrumentation code that counts method calls; needs -Yinstrument to be set, too.")
/** Dottydoc specific settings that are not used in scala3doc */
val docSnapshot: Setting[Boolean] = BooleanSetting("-doc-snapshot", "Generate a documentation snapshot for the current Dotty version")
val projectUrl: Setting[String] = StringSetting (
"-project-url",
"project repository homepage",
"The source repository of your project.",
""
)
val wikiSyntax: Setting[Boolean] = BooleanSetting("-Xwiki-syntax", "Retains the Scala2 behavior of using Wiki Syntax in Scaladoc.")
}
I had to find this again today when I was trying to understand the scalacOptions that are available in sbt’s build.sbt file, specifically trying to understand what source:3.1 means:
scalacOptions ++= Seq( "-deprecation", // emit warning and location for usages of deprecated APIs "-explain", // explain errors in more detail "-explain-types", // explain type errors in more detail "-feature", // emit warning and location for usages of features that should be imported explicitly "-indent", // allow significant indentation. "-new-syntax", // require `then` and `do` in control expressions. "-print-lines", // show source code line numbers. "-unchecked", // enable additional warnings where generated code depends on assumptions "-Ykind-projector", // allow `*` as wildcard to be compatible with kind projector "-Xfatal-warnings", // fail the compilation if there are any warnings "-Xmigration", // warn about constructs whose behavior may have changed since version "-source:3.1" )
The original and up-to-date file can be found here on Github.
