Ignore resetting if preferPrevious

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -365,7 +365,7 @@ private sealed trait XSettings:
 
   /** Pipeline compilation options */
   val XjavaTasty: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xjava-tasty", "Pickler phase should compute TASTy for .java defined symbols for use by build tools", aliases = List("-Xpickle-java", "-Yjava-tasty", "-Ypickle-java"), preferPrevious = true)
-  val XearlyTastyOutput: Setting[AbstractFile] = OutputSetting(AdvancedSetting, "Xearly-tasty-output", "directory|jar", "Destination to write generated .tasty files to for use in pipelined compilation.", NoAbstractFile, aliases = List("-Xpickle-write", "-Yearly-tasty-output", "-Ypickle-write"), preferPrevious = true)
+  val XearlyTastyOutput: Setting[AbstractFile] = OutputSetting(AdvancedSetting, "Xearly-tasty-output", "directory|jar", "Destination to write generated .tasty files to for use in pipelined compilation.", NoAbstractFile, aliases = List("-Xpickle-write", "-Yearly-tasty-output", "-Ypickle-write"), ignoreInvalidArgs = true, preferPrevious = true)
   val XallowOutlineFromTasty: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xallow-outline-from-tasty", "Allow outline TASTy to be loaded with the -from-tasty option.", aliases = List("-Yallow-outline-from-tasty"))
 
   val XmixinForceForwarders = ChoiceSetting(

compiler/src/dotty/tools/dotc/config/Settings.scala

@@ -267,7 +267,9 @@ object Settings:
             else return missingArg
           def doSet(arg: String, args: List[String]) =
             ct match
-            case _ if preferPrevious && changed => state.warn(s"Ignoring update of option $name", args)
+            case _ if preferPrevious && changed =>
+              if ignoreInvalidArgs then state.shifted(args)
+              else state.warn(s"Ignoring update of option $name", args)
             case ListTag => setMultivalue(arg, args)
             case StringTag => setString(arg, args)
             case OutputTag => setOutput(arg, args)
@@ -476,8 +478,8 @@ object Settings:
     def MultiStringSetting(category: SettingCategory, name: String, helpArg: String, descr: String, default: List[String] = Nil, aliases: List[SettingAlias] = Nil, deprecation: Option[Deprecation] = None): Setting[List[String]] =
       publish(Setting(category, prependName(name), descr, default, helpArg, aliases = aliases, deprecation = deprecation))
 
-    def OutputSetting(category: SettingCategory, name: String, helpArg: String, descr: String, default: AbstractFile, aliases: List[SettingAlias] = Nil, preferPrevious: Boolean = false, deprecation: Option[Deprecation] = None): Setting[AbstractFile] =
-      publish(Setting(category, prependName(name), descr, default, helpArg, aliases = aliases, preferPrevious = preferPrevious, deprecation = deprecation))
+    def OutputSetting(category: SettingCategory, name: String, helpArg: String, descr: String, default: AbstractFile, aliases: List[SettingAlias] = Nil, preferPrevious: Boolean = false, deprecation: Option[Deprecation] = None, ignoreInvalidArgs: Boolean = false): Setting[AbstractFile] =
+      publish(Setting(category, prependName(name), descr, default, helpArg, aliases = aliases, preferPrevious = preferPrevious, deprecation = deprecation, ignoreInvalidArgs = ignoreInvalidArgs))
 
     def PathSetting(category: SettingCategory, name: String, descr: String, default: String, aliases: List[SettingAlias] = Nil, deprecation: Option[Deprecation] = None): Setting[String] =
       publish(Setting(category, prependName(name), descr, default, aliases = aliases, deprecation = deprecation))

compiler/test/dotty/tools/dotc/SettingsTests.scala

@@ -14,6 +14,7 @@ import dotty.tools.vulpix.TestConfiguration.mkClasspath
 import dotty.tools.io.PlainDirectory
 import dotty.tools.io.Directory
 import dotty.tools.dotc.config.ScalaVersion
+import io.PlainFile, PlainFile.*
 
 import java.nio.file.*, Files.*
 
@@ -253,8 +254,6 @@ class SettingsTests:
     assertTrue(summary.warnings.forall(_.contains("updated")))
 
   @Test def `dir option also warns`: Unit =
-    import java.nio.file.Paths
-    import io.PlainFile, PlainFile.*
     val abc: PlainFile = Paths.get("a", "b", "c").toPlainFile
     object Settings extends SettingGroup:
       val option = OutputSetting(RootSetting, "option", "out", "A file", Paths.get("a", "b", "c").toPlainFile)
@@ -474,6 +473,25 @@ class SettingsTests:
     assertThrows[AssertionError](_.getMessage.contains("replaced by")):
       flag
 
+  @Test def `Ignored setting shifts args`: Unit =
+    object Settings extends SettingGroup:
+      val foo = BooleanSetting(RootSetting, "foo", "foo", ignoreInvalidArgs = true, preferPrevious = true)
+      val bar = BooleanSetting(RootSetting, "bar", "bar")
+      val baz = OutputSetting(RootSetting, "out", "dir", "A file", default = Paths.get("out", "baz").toPlainFile,
+        ignoreInvalidArgs = true, preferPrevious = true)
+    import Settings.*
+    Using.resource(createTempDirectory("testDir")): dir =>
+      val out = createDirectory(dir.resolve("x"))
+      val args = List("-out", out.toString, "-out", s"$dir/y", "-foo:true", "-foo:false", "-bar:true")
+      val summary = processArguments(args, processAll = true)
+      assertTrue(summary.errors.mkString(","), summary.errors.isEmpty)
+      assertEquals(1, summary.warnings.size)
+      assertEquals("Ignoring conflicting value for Boolean flag -foo", summary.warnings.head)
+      assertEquals(1L, Files.list(dir).count) // second -out is ignored, no dir/y exists
+      withProcessedArgs(summary):
+        assertTrue(foo.value)
+        assertTrue(bar.value)
+
   // use the supplied summary for evaluating settings
   private def withProcessedArgs(summary: ArgsSummary)(f: SettingsState ?=> Unit) = f(using summary.sstate)
 

compiler/test/dotty/tools/dotc/config/ScalaSettingsTests.scala

@@ -3,6 +3,7 @@ package config
 
 import CommandLineParser.tokenize
 import Settings._
+import dotty.tools.Useables.given
 import dotty.tools.dotc.config.ScalaSettingCategories._
 import org.junit.Test
 import org.junit.Assert._
@@ -317,4 +318,23 @@ class ScalaSettingsTests:
     assertEquals("Option -Xfatal-warnings is a deprecated alias: use -Werror instead", result.warnings.head)
     assertEquals(0, result.errors.length)
 
+  // see sbt-test/pipelining/pipelining-test/test
+  @Test def `-Xearly-tasty-output preferPrevious does not warn on change of value`: Unit =
+    val settings = ScalaSettings
+    val conf = Using.resource(Files.createTempDirectory("testDir")): dir =>
+      val args = List("-Ypickle-write", s"$dir/foo.jar", "-Ypickle-write", s"$dir/bar.jar")
+      val argSummary = ArgsSummary(settings.defaultState, args, errors = Nil, warnings = Nil)
+      settings.processArguments(argSummary, processAll = true, skipped = Nil)
+    assert(conf.warnings.isEmpty, s"WARN: ${conf.warnings}")
+    assert(conf.errors.isEmpty, s"ERROR: ${conf.errors}")
+
+  @Test def `-Xjava-tasty preferPrevious warns on change of value`: Unit =
+    val settings = ScalaSettings
+    val args = List("-Xjava-tasty", "-Xjava-tasty:false")
+    val argSummary = ArgsSummary(settings.defaultState, args, errors = Nil, warnings = Nil)
+    val conf = settings.processArguments(argSummary, processAll = true, skipped = Nil)
+    assertEquals(s"Warnings [${conf.warnings}]", 1, conf.warnings.size)
+    assertEquals("Ignoring conflicting value for Boolean flag -Xjava-tasty", conf.warnings.head)
+    assert(conf.errors.isEmpty, s"ERROR: ${conf.errors}")
+
 end ScalaSettingsTests