[nomerge] on 2.12, -release should not set -target

lrytz · lrytz · commit 9648941c3568 · 2022-08-16T10:47:56.000+02:00
diff --git a/src/compiler/scala/tools/nsc/Global.scala b/src/compiler/scala/tools/nsc/Global.scala
@@ -1369,16 +1369,6 @@ class Global(var currentSettings: Settings, reporter0: Reporter)
       settings.userSetSettings filter (_.isDeprecated) foreach { s =>
         runReporting.deprecationWarning(NoPosition, s.name + " is deprecated: " + s.deprecationMessage.get, "", "", "")
       }
-      if (!StandardScalaSettings.SupportedTargetVersions.contains(settings.target.value)) {
-        runReporting.deprecationWarning(
-          NoPosition,
-          settings.target.name + ":" + settings.target.value + " is deprecated and has no effect, setting to " + StandardScalaSettings.DefaultTargetVersion,
-          since = "2.12.16",
-          site = "",
-          origin = ""
-        )
-        settings.target.value = StandardScalaSettings.DefaultTargetVersion
-      }
       settings.conflictWarning.foreach(runReporting.warning(NoPosition, _, WarningCategory.Other, site = ""))
     }
 
diff --git a/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/StandardScalaSettings.scala
@@ -13,7 +13,7 @@
 package scala.tools.nsc
 package settings
 
-import scala.tools.nsc.settings.StandardScalaSettings.{AllTargetVersions, DefaultTargetVersion, SupportedTargetVersions}
+import scala.tools.nsc.settings.StandardScalaSettings._
 import scala.tools.util.PathResolver.Defaults
 import scala.util.Properties.{isJavaAtLeast, javaSpecVersion}
 
@@ -71,15 +71,17 @@ trait StandardScalaSettings { _: MutableSettings =>
       if (releaseValue.map(_.toInt < setting.value.toInt).getOrElse(false))
         errorFn("-release cannot be less than -target")
       if (!setting.deprecationMessage.isDefined)
-        if (SupportedTargetVersions.contains(setting.value))
-          setting.withDeprecationMessage("Use -release instead to compile against the correct platform API.")
-        else {
+        if (setting.value.toInt > MaxSupportedTargetVersion) {
+          setting.withDeprecationMessage(s"Scala 2.12 cannot emit valid class files for targets newer than $MaxSupportedTargetVersion (this is possible with Scala 2.13). Use -release to compile against a specific platform API version.")
+          setting.value = DefaultTargetVersion
+        } else if (setting.value.toInt < MinSupportedTargetVersion) {
           setting.withDeprecationMessage(s"${setting.name}:${setting.value} is deprecated, forcing use of $DefaultTargetVersion")
-          setting.value = DefaultTargetVersion   // triggers this hook
+          setting.value = DefaultTargetVersion
         }
     }
     .withAbbreviation("--target")
-  def targetValue: String = releaseValue.getOrElse(target.value)
+  // Unlike 2.13, don't use `releaseValue.getOrElse(target.value)`, because 2.12 doesn't have a fix for scala-dev#408
+  def targetValue: String = target.value
   val unchecked =      BooleanSetting ("-unchecked", "Enable additional warnings where generated code depends on assumptions. See also -Wconf.") withAbbreviation "--unchecked" withPostSetHook { s =>
     if (s.value) Wconf.tryToSet(List(s"cat=unchecked:w"))
     else Wconf.tryToSet(List(s"cat=unchecked:s"))
@@ -115,9 +117,9 @@ object StandardScalaSettings {
     case SpecificScalaVersion(major, _, _, _) => major
     case _ => 19
   }
+  val MaxSupportedTargetVersion = 8
   val DefaultTargetVersion = "8"
 
   private val AllTargetVersions = (MinTargetVersion to MaxTargetVersion).map(_.toString).toList
-  val SupportedTargetVersions: List[String] = (MinSupportedTargetVersion to MaxTargetVersion).map(_.toString).toList
   val AllPermissibleTargetValues: List[String] = AllTargetVersions.flatMap(v => v :: s"jvm-1.$v" :: s"jvm-$v" :: s"1.$v" :: Nil)
 }
diff --git a/test/files/run/t12543-target.scala b/test/files/run/t12543-target.scala
@@ -0,0 +1,8 @@
+// javaVersion: 11+
+// scalac: -release:11
+
+trait T { val x = 42 }
+class C extends T
+object Test {
+  def main(args: Array[String]): Unit = { new C(); () }
+}
