Merge branch 'main' into feature/preview

.github/workflows/ci.yaml

@@ -630,7 +630,10 @@ jobs:
         - ${{ github.workspace }}/../../cache/general:/root/.cache
     strategy:
       matrix:
-        branch: [main, lts-3.3]
+        series: [
+          {repository: scala/scala3, branch: main}, # Scala Next nightly
+          {repository: scala/scala3-lts, branch: lts-3.3} # Scala LTS nightly
+        ]
     needs: [test_non_bootstrapped, test, mima, community_build_a, community_build_b, community_build_c, test_sbt, test_java8]
     if: "(github.event_name == 'schedule' || github.event_name == 'workflow_dispatch') && github.repository == 'scala/scala3'"
     env:
@@ -660,7 +663,8 @@ jobs:
       - name: Git Checkout
         uses: actions/checkout@v4
         with:
-          ref: ${{ matrix.branch }}
+          repository: ${{ matrix.series.repository }}
+          ref: ${{ matrix.series.branch }}
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -832,7 +836,7 @@ jobs:
           sha256sum "${msiInstaller}" > "${msiInstaller}.sha256"
 
       - name: Install GH CLI
-        uses: dev-hanz-ops/[email protected].0
+        uses: dev-hanz-ops/[email protected].1
         with:
           gh-cli-version: 2.59.0
 

.github/workflows/lts-backport.yaml

@@ -15,7 +15,7 @@ jobs:
         with:
           fetch-depth: 0
       - uses: coursier/cache-action@v6
-      - uses: VirtusLab/[email protected].1
+      - uses: VirtusLab/[email protected].2
       - run: scala-cli ./project/scripts/addToBackportingProject.scala -- ${{ github.sha }}
         env:
           GRAPHQL_API_TOKEN: ${{ secrets.GRAPHQL_API_TOKEN }}

.github/workflows/spec.yml

@@ -49,7 +49,7 @@ jobs:
         env:
           USER_FOR_TEST: ${{ secrets.SPEC_DEPLOY_USER }}
         if: ${{ env.USER_FOR_TEST != '' }}
-        uses: burnett01/[email protected].1
+        uses: burnett01/[email protected].2
         with:
           switches: -rzv
           path: docs/_spec/_site/

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

@@ -818,7 +818,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
 
       methSymbol  = dd.symbol
       jMethodName = methSymbol.javaSimpleName
-      returnType  = asmMethodType(dd.symbol).returnType
+      returnType  = asmMethodType(methSymbol).returnType
       isMethSymStaticCtor = methSymbol.isStaticConstructor
 
       resetMethodBookkeeping(dd)
@@ -915,7 +915,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
             for (p <- params) { emitLocalVarScope(p.symbol, veryFirstProgramPoint, onePastLastProgramPoint, force = true) }
           }
 
-          if (isMethSymStaticCtor) { appendToStaticCtor(dd) }
+          if (isMethSymStaticCtor) { appendToStaticCtor() }
         } // end of emitNormalMethodBody()
 
         lineNumber(rhs)
@@ -936,7 +936,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
      *
      *  TODO document, explain interplay with `fabricateStaticInitAndroid()`
      */
-    private def appendToStaticCtor(dd: DefDef): Unit = {
+    private def appendToStaticCtor(): Unit = {
 
       def insertBefore(
             location: asm.tree.AbstractInsnNode,

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

@@ -12,10 +12,10 @@ import java.util.zip.{CRC32, Deflater, ZipEntry, ZipOutputStream}
 
 import dotty.tools.dotc.core.Contexts.*
 import dotty.tools.dotc.core.Decorators.em
+import dotty.tools.dotc.util.chaining.*
 import dotty.tools.io.{AbstractFile, PlainFile, VirtualFile}
 import dotty.tools.io.PlainFile.toPlainFile
 import BTypes.InternalName
-import scala.util.chaining.*
 import dotty.tools.io.JarArchive
 
 import scala.language.unsafeNulls

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -7,9 +7,8 @@ import typer.{TyperPhase, RefChecks}
 import parsing.Parser
 import Phases.Phase
 import transform.*
-import dotty.tools.backend
 import backend.jvm.{CollectSuperCalls, GenBCode}
-import localopt.StringInterpolatorOpt
+import localopt.{StringInterpolatorOpt, DropForMap}
 
 /** The central class of the dotc compiler. The job of a compiler is to create
  *  runs, which process given `phases` in a given `rootContext`.
@@ -34,8 +33,7 @@ class Compiler {
   protected def frontendPhases: List[List[Phase]] =
     List(new Parser) ::             // Compiler frontend: scanner, parser
     List(new TyperPhase) ::         // Compiler frontend: namer, typer
-    List(new CheckUnused.PostTyper) :: // Check for unused elements
-    List(new CheckShadowing) :: // Check shadowing elements
+    List(CheckUnused.PostTyper(), CheckShadowing()) :: // Check for unused, shadowed elements
     List(new YCheckPositions) ::    // YCheck positions
     List(new sbt.ExtractDependencies) :: // Sends information on classes' dependencies to sbt via callbacks
     List(new semanticdb.ExtractSemanticDB.ExtractSemanticInfo) :: // Extract info into .semanticdb files
@@ -51,10 +49,10 @@ class Compiler {
     List(new sbt.ExtractAPI) ::     // Sends a representation of the API of classes to sbt via callbacks
     List(new Inlining) ::           // Inline and execute macros
     List(new PostInlining) ::       // Add mirror support for inlined code
-    List(new CheckUnused.PostInlining) ::  // Check for unused elements
     List(new Staging) ::            // Check staging levels and heal staged types
     List(new Splicing) ::           // Replace level 1 splices with holes
     List(new PickleQuotes) ::       // Turn quoted trees into explicit run-time data structures
+    List(new CheckUnused.PostInlining) ::  // Check for unused elements
     Nil
 
   /** Phases dealing with the transformation from pickled trees to backend trees */
@@ -70,7 +68,8 @@ class Compiler {
          new InlineVals,             // Check right hand-sides of an `inline val`s
          new ExpandSAMs,             // Expand single abstract method closures to anonymous classes
          new ElimRepeated,           // Rewrite vararg parameters and arguments
-         new RefChecks) ::           // Various checks mostly related to abstract members and overriding
+         new RefChecks,              // Various checks mostly related to abstract members and overriding
+         new DropForMap) ::          // Drop unused trailing map calls in for comprehensions
     List(new semanticdb.ExtractSemanticDB.AppendDiagnostics) :: // Attach warnings to extracted SemanticDB and write to .semanticdb file
     List(new init.Checker) ::        // Check initialization of objects
     List(new ProtectedAccessors,     // Add accessors for protected members

compiler/src/dotty/tools/dotc/Run.scala

@@ -38,6 +38,7 @@ import Run.Progress
 import scala.compiletime.uninitialized
 import dotty.tools.dotc.transform.MegaPhase
 import dotty.tools.dotc.transform.Pickler.AsyncTastyHolder
+import java.util.{Timer, TimerTask}
 
 /** A compiler run. Exports various methods to compile source files */
 class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with ConstraintRunInfo {
@@ -382,7 +383,7 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
         initializeAsyncTasty()
       else () => {}
 
-    runPhases(allPhases = fusedPhases)(using runCtx)
+    showProgress(runPhases(allPhases = fusedPhases)(using runCtx))
     cancelAsyncTasty()
 
     ctx.reporter.finalizeReporting()
@@ -433,6 +434,26 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
       process()(using unitCtx)
     }
 
+  /** If set to true, prints every 10 seconds the files currently being compiled.
+   *  Turn this flag on if you want to find out which test among many takes more time
+   *  to compile than the others or causes an infinite loop in the compiler.
+   */
+  private inline val debugPrintProgress = false
+
+  /** Period between progress reports, in ms */
+  private inline val printProgressPeriod = 10000
+
+  /** Shows progress if debugPrintProgress is true */
+  private def showProgress(proc: => Unit)(using Context): Unit =
+    if !debugPrintProgress then proc
+    else
+      val watchdog = new TimerTask:
+        def run() = println(i"[compiling $units]")
+      try
+        new Timer().schedule(watchdog, printProgressPeriod, printProgressPeriod)
+        proc
+      finally watchdog.cancel()
+
   private sealed trait PrintedTree
   private /*final*/ case class SomePrintedTree(phase: String, tree: String) extends PrintedTree
   private object NoPrintedTree extends PrintedTree

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

@@ -47,6 +47,14 @@ object desugar {
    */
   val UntupledParam: Property.Key[Unit] = Property.StickyKey()
 
+  /** An attachment key to indicate that a ValDef originated from a pattern.
+   */
+  val PatternVar: Property.Key[Unit] = Property.StickyKey()
+
+  /** An attachment key for Trees originating in for-comprehension, such as tupling of assignments.
+   */
+  val ForArtifact: Property.Key[Unit] = Property.StickyKey()
+
   /** An attachment key to indicate that a ValDef is an evidence parameter
    *  for a context bound.
    */
@@ -56,6 +64,11 @@ object desugar {
    */
   val PolyFunctionApply: Property.Key[Unit] = Property.StickyKey()
 
+  /** An attachment key to indicate that an Apply is created as a last `map`
+   *  scall in a for-comprehension.
+   */
+  val TrailingForMap: Property.Key[Unit] = Property.StickyKey()
+
   /** What static check should be applied to a Match? */
   enum MatchCheck {
     case None, Exhaustive, IrrefutablePatDef, IrrefutableGenFrom
@@ -410,6 +423,7 @@ object desugar {
           .withMods(Modifiers(
             meth.mods.flags & (AccessFlags | Synthetic) | (vparam.mods.flags & Inline),
             meth.mods.privateWithin))
+          .withSpan(vparam.rhs.span)
         val rest = defaultGetters(vparams :: paramss1, n + 1)
         if vparam.rhs.isEmpty then rest else defaultGetter :: rest
       case _ :: paramss1 =>  // skip empty parameter lists and type parameters
@@ -859,7 +873,7 @@ object desugar {
       val nu = vparamss.foldLeft(makeNew(classTypeRef)) { (nu, vparams) =>
         val app = Apply(nu, vparams.map(refOfDef))
         vparams match {
-          case vparam :: _ if vparam.mods.is(Given) || vparam.name.is(ContextBoundParamName) =>
+          case vparam :: _ if vparam.mods.isOneOf(GivenOrImplicit) || vparam.name.is(ContextBoundParamName) =>
             app.setApplyKind(ApplyKind.Using)
           case _ => app
         }
@@ -1507,7 +1521,7 @@ object desugar {
       val matchExpr =
         if (tupleOptimizable) rhs
         else
-          val caseDef = CaseDef(pat, EmptyTree, makeTuple(ids))
+          val caseDef = CaseDef(pat, EmptyTree, makeTuple(ids).withAttachment(ForArtifact, ()))
           Match(makeSelector(rhs, MatchCheck.IrrefutablePatDef), caseDef :: Nil)
       vars match {
         case Nil if !mods.is(Lazy) =>
@@ -1537,6 +1551,7 @@ object desugar {
                   ValDef(named.name.asTermName, tpt, selector(n))
                     .withMods(mods)
                     .withSpan(named.span)
+                    .withAttachment(PatternVar, ())
                 )
           flatTree(firstDef :: restDefs)
       }
@@ -1922,6 +1937,7 @@ object desugar {
     val vdef = ValDef(named.name.asTermName, tpt, rhs)
       .withMods(mods)
       .withSpan(original.span.withPoint(named.span.start))
+      .withAttachment(PatternVar, ())
     val mayNeedSetter = valDef(vdef)
     mayNeedSetter
   }
@@ -1956,14 +1972,8 @@ object desugar {
      *
      *  3.
      *
-     *    for (P <- G) yield P  ==>  G
-     *
-     *  If betterFors is enabled, P is a variable or a tuple of variables and G is not a withFilter.
-     *
      *    for (P <- G) yield E  ==>  G.map (P => E)
      *
-     *    Otherwise
-     *
      *  4.
      *
      *    for (P_1 <- G_1; P_2 <- G_2; ...) ...
@@ -2136,14 +2146,20 @@ object desugar {
           case (Tuple(ts1), Tuple(ts2)) => ts1.corresponds(ts2)(deepEquals)
           case _ => false
 
+      def markTrailingMap(aply: Apply, gen: GenFrom, selectName: TermName): Unit =
+        if betterForsEnabled
+          && selectName == mapName
+          && gen.checkMode != GenCheckMode.Filtered // results of withFilter have the wrong type
+          && (deepEquals(gen.pat, body) || deepEquals(body, Tuple(Nil)))
+        then
+          aply.putAttachment(TrailingForMap, ())
+
       enums match {
         case Nil if betterForsEnabled => body
         case (gen: GenFrom) :: Nil =>
-          if betterForsEnabled
-            && gen.checkMode != GenCheckMode.Filtered // results of withFilter have the wrong type
-            && deepEquals(gen.pat, body)
-          then gen.expr  // avoid a redundant map with identity
-          else Apply(rhsSelect(gen, mapName), makeLambda(gen, body))
+          val aply = Apply(rhsSelect(gen, mapName), makeLambda(gen, body))
+          markTrailingMap(aply, gen, mapName)
+          aply
         case (gen: GenFrom) :: (rest @ (GenFrom(_, _, _) :: _)) =>
           val cont = makeFor(mapName, flatMapName, rest, body)
           Apply(rhsSelect(gen, flatMapName), makeLambda(gen, cont))
@@ -2154,7 +2170,9 @@ object desugar {
           val selectName =
             if rest.exists(_.isInstanceOf[GenFrom]) then flatMapName
             else mapName
-          Apply(rhsSelect(gen, selectName), makeLambda(gen, cont))
+          val aply = Apply(rhsSelect(gen, selectName), makeLambda(gen, cont))
+          markTrailingMap(aply, gen, selectName)
+          aply
         case (gen: GenFrom) :: (rest @ GenAlias(_, _) :: _) =>
           val (valeqs, rest1) = rest.span(_.isInstanceOf[GenAlias])
           val pats = valeqs map { case GenAlias(pat, _) => pat }
@@ -2167,7 +2185,7 @@ object desugar {
               case _ => Modifiers()
             makePatDef(valeq, mods, defpat, rhs)
           }
-          val rhs1 = makeFor(nme.map, nme.flatMap, GenFrom(defpat0, gen.expr, gen.checkMode) :: Nil, Block(pdefs, makeTuple(id0 :: ids)))
+          val rhs1 = makeFor(nme.map, nme.flatMap, GenFrom(defpat0, gen.expr, gen.checkMode) :: Nil, Block(pdefs, makeTuple(id0 :: ids).withAttachment(ForArtifact, ())))
           val allpats = gen.pat :: pats
           val vfrom1 = GenFrom(makeTuple(allpats), rhs1, GenCheckMode.Ignore)
           makeFor(mapName, flatMapName, vfrom1 :: rest1, body)

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

@@ -98,17 +98,17 @@ object MainProxies {
       val body = Try(call, handler :: Nil, EmptyTree)
       val mainArg = ValDef(nme.args, TypeTree(defn.ArrayType.appliedTo(defn.StringType)), EmptyTree)
         .withFlags(Param)
-      /** Replace typed `Ident`s that have been typed with a TypeSplice with the reference to the symbol.
-       *  The annotations will be retype-checked in another scope that may not have the same imports.
+
+      /** This context is used to create the `TypeSplices` wrapping annotations
+       *  below. These should have `mainFun` as their owner (and not the
+       *  enclosing package class that we would get otherwise) so that
+       *  subsequent owner changes (for example in `Typer.typedTypedSplice`) are
+       *  correct. See #22364 and associated tests.
        */
-      def insertTypeSplices = new TreeMap {
-          override def transform(tree: Tree)(using Context): Tree = tree match
-            case tree: tpd.Ident @unchecked => TypedSplice(tree)
-            case tree => super.transform(tree)
-      }
+      val annotsCtx = ctx.fresh.setOwner(mainFun)
       val annots = mainFun.annotations
         .filterNot(_.matches(defn.MainAnnot))
-        .map(annot => insertTypeSplices.transform(annot.tree))
+        .map(annot => TypedSplice(annot.tree)(using annotsCtx))
       val mainMeth = DefDef(nme.main, (mainArg :: Nil) :: Nil, TypeTree(defn.UnitType), body)
         .withFlags(JavaStatic | Synthetic)
         .withAnnotations(annots)

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

@@ -466,6 +466,8 @@ trait UntypedTreeInfo extends TreeInfo[Untyped] { self: Trees.Instance[Untyped]
    */
   private def defKind(tree: Tree)(using Context): FlagSet = unsplice(tree) match {
     case EmptyTree | _: Import => NoInitsInterface
+    case tree: TypeDef if ctx.settings.YcompileScala2Library.value =>
+      if (tree.isClassDef) EmptyFlags else NoInitsInterface
     case tree: TypeDef => if (tree.isClassDef) NoInits else NoInitsInterface
     case tree: DefDef =>
       if tree.unforcedRhs == EmptyTree
@@ -477,6 +479,8 @@ trait UntypedTreeInfo extends TreeInfo[Untyped] { self: Trees.Instance[Untyped]
         NoInitsInterface
       else if tree.mods.is(Given) && tree.paramss.isEmpty then
         EmptyFlags // might become a lazy val: TODO: check whether we need to suppress NoInits once we have new lazy val impl
+      else if ctx.settings.YcompileScala2Library.value then
+        EmptyFlags
       else
         NoInits
     case tree: ValDef => if (tree.unforcedRhs == EmptyTree) NoInitsInterface else EmptyFlags

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

@@ -461,8 +461,11 @@ object Trees {
         else if qualifier.span.exists && qualifier.span.start > span.point then // right associative
           val realName = name.stripModuleClassSuffix.lastPart
           Span(span.start, span.start + realName.length, point)
-        else
-          Span(point, span.end, point)
+        else if span.pointMayBeIncorrect then
+          val realName = name.stripModuleClassSuffix.lastPart
+          val probablyPoint = span.end - realName.length
+          Span(probablyPoint, span.end, probablyPoint)
+        else Span(point, span.end, point)
       else span
   }
 

compiler/src/dotty/tools/dotc/cc/Setup.scala

@@ -570,7 +570,7 @@ class Setup extends PreRecheck, SymTransformer, SetupAPI:
               // For example, `(x: T, y: x.f.type) => Unit`. In this case, when we
               // substitute `x.f.type`, `x` becomes a `TermParamRef`. But the new method
               // type is still under initialization and `paramInfos` is still `null`,
-              // so the new `NamedType` will not have a denoation.
+              // so the new `NamedType` will not have a denotation.
               def adaptedInfo(psym: Symbol, info: mt.PInfo): mt.PInfo = mt.companion match
                 case mtc: MethodTypeCompanion => mtc.adaptParamInfo(psym, info).asInstanceOf[mt.PInfo]
                 case _ => info

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

@@ -7,7 +7,7 @@ import Settings.*
 import core.Contexts.*
 import printing.Highlighting
 
-import scala.util.chaining.given
+import dotty.tools.dotc.util.chaining.*
 import scala.PartialFunction.cond
 
 trait CliCommand: