Synchronizing defTree for local variable access

Author: EnzeXing

community-build/community-projects/akka

@@ -357,8 +357,8 @@ object projects:
   lazy val stdLib213 = SbtCommunityProject(
     project       = "stdLib213",
     extraSbtArgs  = List("-Dscala.build.compileWithDotty=true"),
-    sbtTestCommand   = """library/compile""",
-    sbtPublishCommand = """set library/Compile/packageDoc/publishArtifact := false; library/publishLocal""",
+    sbtTestCommand   = """set Global / fatalWarnings := false; library/compile""",
+    sbtPublishCommand = """set Global / fatalWarnings := false; set library/Compile/packageDoc/publishArtifact := false; library/publishLocal""",
     // sbtDocCommand = "library/doc" // Does no compile? No idea :/
   )
 

community-build/src/scala/dotty/communitybuild/projects.scala

@@ -21,6 +21,7 @@ import dotty.tools.dotc.core.Names.Name
 import dotty.tools.dotc.core.NameKinds.ExpandedName
 import dotty.tools.dotc.core.Signature
 import dotty.tools.dotc.core.StdNames._
+import dotty.tools.dotc.core.NameKinds
 import dotty.tools.dotc.core.Symbols._
 import dotty.tools.dotc.core.Types
 import dotty.tools.dotc.core.Types._
@@ -507,7 +508,7 @@ trait BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
      *
      * must-single-thread
      */
-    private def addForwarder(jclass: asm.ClassVisitor, module: Symbol, m: Symbol): Unit = {
+    private def addForwarder(jclass: asm.ClassVisitor, module: Symbol, m: Symbol, isSynthetic: Boolean): Unit = {
       val moduleName     = internalName(module)
       val methodInfo     = module.thisType.memberInfo(m)
       val paramJavaTypes: List[BType] = methodInfo.firstParamTypes map toTypeKind
@@ -518,9 +519,10 @@ trait BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
        *  and we don't know what classes might be subclassing the companion class.  See SI-4827.
        */
       // TODO: evaluate the other flags we might be dropping on the floor here.
-      // TODO: ACC_SYNTHETIC ?
       val flags = GenBCodeOps.PublicStatic | (
         if (m.is(JavaVarargs)) asm.Opcodes.ACC_VARARGS else 0
+      ) | (
+        if (isSynthetic) asm.Opcodes.ACC_SYNTHETIC else 0
       )
 
       // TODO needed? for(ann <- m.annotations) { ann.symbol.initialize }
@@ -595,7 +597,16 @@ trait BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
           report.log(s"No forwarder for non-public member $m")
         else {
           report.log(s"Adding static forwarder for '$m' from $jclassName to '$moduleClass'")
-          addForwarder(jclass, moduleClass, m)
+          // It would be simpler to not generate forwarders for these methods,
+          // but that wouldn't be binary-compatible with Scala 3.0.0, so instead
+          // we generate ACC_SYNTHETIC forwarders so Java compilers ignore them.
+          val isSynthetic =
+            m0.name.is(NameKinds.SyntheticSetterName) ||
+            // Only hide bridges generated at Erasure, mixin forwarders are also
+            // marked as bridge but shouldn't be hidden since they don't have a
+            // non-bridge overload.
+            m0.is(Bridge) && m0.initial.validFor.firstPhaseId == erasurePhase.next.id
+          addForwarder(jclass, moduleClass, m, isSynthetic)
         }
       }
     }

compiler/src/dotty/tools/backend/jvm/BCodeHelpers.scala

@@ -18,6 +18,7 @@ import Decorators._
 import Flags._
 import dotty.tools.dotc.ast.Trees._
 import Names._
+import NameKinds.DefaultGetterName
 import Types._
 import Symbols._
 import Denotations._
@@ -1069,6 +1070,14 @@ class JSCodeGen()(using genCtx: Context) {
       } else if (sym.isJSNativeCtorDefaultParam) {
         // #11592
         None
+      } else if (sym.is(Bridge) && sym.name.is(DefaultGetterName) && currentClassSym.isNonNativeJSClass) {
+        /* #12572 Bridges for default accessors in non-native JS classes must not be emitted,
+         * because they call another default accessor, making their entire body an
+         * <undefined-param> that cannot be eliminated.
+         * Such methods are never called anyway, because they are filtered out in
+         * JSExportsGen.defaultGetterDenot().
+         */
+        None
       } else /*if (sym.isClassConstructor && isHijackedBoxedClass(sym.owner)) {
         None
       } else*/ {

compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala

@@ -774,7 +774,7 @@ final class JSExportsGen(jsCodeGen: JSCodeGen)(using Context) {
     else sym.owner
 
   private def defaultGetterDenot(targetSym: Symbol, sym: Symbol, paramIndex: Int): Denotation =
-    targetSym.info.member(DefaultGetterName(sym.name.asTermName, paramIndex))
+    targetSym.info.memberBasedOnFlags(DefaultGetterName(sym.name.asTermName, paramIndex), excluded = Bridge)
 
   private def defaultGetterDenot(sym: Symbol, paramIndex: Int): Denotation =
     defaultGetterDenot(targetSymForDefaultGetter(sym), sym, paramIndex)

compiler/src/dotty/tools/backend/sjs/JSExportsGen.scala

@@ -963,8 +963,10 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
 
     /** `tree.isInstanceOf[tp]`, with special treatment of singleton types */
     def isInstance(tp: Type)(using Context): Tree = tp.dealias match {
+      case ConstantType(c) if c.tag == StringTag =>
+        singleton(tp).equal(tree)
       case tp: SingletonType =>
-        if (tp.widen.derivesFrom(defn.ObjectClass))
+        if tp.widen.derivesFrom(defn.ObjectClass) then
           tree.ensureConforms(defn.ObjectType).select(defn.Object_eq).appliedTo(singleton(tp))
         else
           singleton(tp).equal(tree)

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -7,7 +7,8 @@ import Settings._
 import core.Contexts._
 import Properties._
 
-import scala.collection.JavaConverters._
+ import scala.PartialFunction.cond
+ import scala.collection.JavaConverters._
 
 trait CliCommand:
 
@@ -107,7 +108,7 @@ trait CliCommand:
           // For now, skip the default values that do not make sense for the end user.
           // For example 'false' for the version command.
           ""
-      s"${formatName(s.name)} ${formatDescription(s.description)}${formatSetting("Default", defaultValue)}${formatSetting("Choices", s.legalChoices)}"
+      s"${formatName(s.name)} ${formatDescription(shortHelp(s))}${formatSetting("Default", defaultValue)}${formatSetting("Choices", s.legalChoices)}"
     ss.map(helpStr).mkString("", "\n", s"\n${formatName("@<file>")} ${formatDescription("A text file containing compiler arguments (options and source files).")}\n")
   end availableOptionsMsg
 
@@ -123,15 +124,30 @@ trait CliCommand:
     prefix + "\n" + availableOptionsMsg(cond)
 
   protected def isStandard(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
-    !isAdvanced(s) && !isPrivate(s)
+    !isVerbose(s) && !isWarning(s) && !isAdvanced(s) && !isPrivate(s) || s.name == "-Werror" || s.name == "-Wconf"
+  protected def isVerbose(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
+    s.name.startsWith("-V") && s.name != "-V"
+  protected def isWarning(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
+    s.name.startsWith("-W") && s.name != "-W" || s.name == "-Xlint"
   protected def isAdvanced(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
     s.name.startsWith("-X") && s.name != "-X"
   protected def isPrivate(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
     s.name.startsWith("-Y") && s.name != "-Y"
+  protected def shortHelp(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): String =
+    s.description.linesIterator.next()
+  protected def isHelping(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
+    cond(s.value) {
+      case ss: List[?] if s.isMultivalue => ss.contains("help")
+      case s: String                     => "help" == s
+    }
 
   /** Messages explaining usage and options */
   protected def usageMessage(using settings: ConcreteSettings)(using SettingsState) =
     createUsageMsg("where possible standard", shouldExplain = false, isStandard)
+  protected def vusageMessage(using settings: ConcreteSettings)(using SettingsState) =
+    createUsageMsg("Possible verbose", shouldExplain = true, isVerbose)
+  protected def wusageMessage(using settings: ConcreteSettings)(using SettingsState) =
+    createUsageMsg("Possible warning", shouldExplain = true, isWarning)
   protected def xusageMessage(using settings: ConcreteSettings)(using SettingsState) =
     createUsageMsg("Possible advanced", shouldExplain = true, isAdvanced)
   protected def yusageMessage(using settings: ConcreteSettings)(using SettingsState) =

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

@@ -14,11 +14,15 @@ abstract class CompilerCommand extends CliCommand:
 
   final def helpMsg(using settings: ScalaSettings)(using SettingsState, Context): String =
     if (settings.help.value) usageMessage
+    else if (settings.Vhelp.value) vusageMessage
+    else if (settings.Whelp.value) wusageMessage
     else if (settings.Xhelp.value) xusageMessage
     else if (settings.Yhelp.value) yusageMessage
     else if (settings.showPlugins.value) ctx.base.pluginDescriptions
     else if (settings.XshowPhases.value) phasesMessage
     else ""
 
   final def isHelpFlag(using settings: ScalaSettings)(using SettingsState): Boolean =
-    Set(settings.help, settings.Xhelp, settings.Yhelp, settings.showPlugins, settings.XshowPhases) exists (_.value)
+    import settings._
+    val flags = Set(help, Vhelp,  Whelp, Xhelp, Yhelp, showPlugins, XshowPhases)
+    flags.exists(_.value) || allSettings.exists(isHelping)

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

@@ -24,7 +24,10 @@ object Config {
   inline val checkConstraintsNonCyclic = false
 
   /** Check that each constraint resulting from a subtype test
-   *  is satisfiable.
+   *  is satisfiable. Also check that a type variable instantiation
+   *  satisfies its constraints.
+   *  Note that this can fail when bad bounds are in scope, like in
+   *  tests/neg/i4721a.scala.
    */
   inline val checkConstraintsSatisfiable = false