Merge branch 'main' into export-diagnostics

Author: tanishiking

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

@@ -372,7 +372,7 @@ object projects:
     sbtTestCommand = """set deriving/scalacOptions -= "-Xfatal-warnings"; set typeable/scalacOptions -= "-Xfatal-warnings"; test""",
       // selectively disable -Xfatal-warnings due to deprecations
     sbtDocCommand = forceDoc("typeable", "deriving", "data"),
-    scalacOptions = Nil // disable -Ysafe-init, due to -Xfatal-warnings
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"), // due to -Xfatal-warnings
   )
 
   lazy val xmlInterpolator = SbtCommunityProject(
@@ -682,7 +682,7 @@ object projects:
     sbtTestCommand = "runCommunityBuild",
     sbtPublishCommand = "publishLocal",
     dependencies = List(scalatest),
-    scalacOptions = List("-language:implicitConversions"), // disabled -Ysafe-init, due to bug in macro
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Xcheck-macros") :+ "-language:implicitConversions", // disabled -Xcheck-macros, due to bug in macro
   )
 
   lazy val onnxScala = SbtCommunityProject(

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

@@ -30,6 +30,7 @@ import scala.tools.asm
 import scala.tools.asm.tree._
 import tpd._
 import dotty.tools.io.AbstractFile
+import dotty.tools.dotc.util
 import dotty.tools.dotc.util.NoSourcePosition
 
 
@@ -106,7 +107,7 @@ class CodeGen(val int: DottyBackendInterface, val primitives: DottyPrimitives)(
   }
 
   // Creates a callback that will be evaluated in PostProcessor after creating a file
-  private def onFileCreated(cls: ClassNode, claszSymbol: Symbol, sourceFile: interfaces.SourceFile): AbstractFile => Unit = clsFile => {
+  private def onFileCreated(cls: ClassNode, claszSymbol: Symbol, sourceFile: util.SourceFile): AbstractFile => Unit = clsFile => {
     val (fullClassName, isLocal) = atPhase(sbtExtractDependenciesPhase) {
       (ExtractDependencies.classNameAsString(claszSymbol), claszSymbol.isLocal)
     }
@@ -115,12 +116,9 @@ class CodeGen(val int: DottyBackendInterface, val primitives: DottyPrimitives)(
     if (ctx.compilerCallback != null)
       ctx.compilerCallback.onClassGenerated(sourceFile, convertAbstractFile(clsFile), className)
 
-    if (ctx.sbtCallback != null) {
-      val jSourceFile = sourceFile.jfile.orElse(null)
-      val cb = ctx.sbtCallback
-      if (isLocal) cb.generatedLocalClass(jSourceFile, clsFile.file)
-      else cb.generatedNonLocalClass(jSourceFile, clsFile.file, className, fullClassName)
-    }
+    ctx.withIncCallback: cb =>
+      if (isLocal) cb.generatedLocalClass(sourceFile, clsFile.jpath)
+      else cb.generatedNonLocalClass(sourceFile, clsFile.jpath, className, fullClassName)
   }
 
   /** Convert a `dotty.tools.io.AbstractFile` into a

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

@@ -7,7 +7,7 @@ import util.Spans._, Types._, Contexts._, Constants._, Names._, NameOps._, Flags
 import Symbols._, StdNames._, Trees._, ContextOps._
 import Decorators._, transform.SymUtils._
 import Annotations.Annotation
-import NameKinds.{UniqueName, EvidenceParamName, DefaultGetterName, WildcardParamName}
+import NameKinds.{UniqueName, ContextBoundParamName, ContextFunctionParamName, DefaultGetterName, WildcardParamName}
 import typer.{Namer, Checking}
 import util.{Property, SourceFile, SourcePosition, Chars}
 import config.Feature.{sourceVersion, migrateTo3, enabled}
@@ -203,10 +203,14 @@ object desugar {
     else vdef1
   end valDef
 
-  def makeImplicitParameters(tpts: List[Tree], implicitFlag: FlagSet, forPrimaryConstructor: Boolean = false)(using Context): List[ValDef] =
-    for (tpt <- tpts) yield {
+  def makeImplicitParameters(
+      tpts: List[Tree], implicitFlag: FlagSet,
+      mkParamName: () => TermName,
+      forPrimaryConstructor: Boolean = false
+  )(using Context): List[ValDef] =
+    for (tpt, i) <- tpts.zipWithIndex yield {
        val paramFlags: FlagSet = if (forPrimaryConstructor) LocalParamAccessor else Param
-       val epname = EvidenceParamName.fresh()
+       val epname = mkParamName()
        ValDef(epname, tpt, EmptyTree).withFlags(paramFlags | implicitFlag)
     }
 
@@ -240,17 +244,27 @@ object desugar {
     val DefDef(_, paramss, tpt, rhs) = meth
     val evidenceParamBuf = ListBuffer[ValDef]()
 
+    var seenContextBounds: Int = 0
     def desugarContextBounds(rhs: Tree): Tree = rhs match
       case ContextBounds(tbounds, cxbounds) =>
         val iflag = if sourceVersion.isAtLeast(`future`) then Given else Implicit
         evidenceParamBuf ++= makeImplicitParameters(
-          cxbounds, iflag, forPrimaryConstructor = isPrimaryConstructor)
+          cxbounds, iflag,
+          // Just like with `makeSyntheticParameter` on nameless parameters of
+          // using clauses, we only need names that are unique among the
+          // parameters of the method since shadowing does not affect
+          // implicit resolution in Scala 3.
+          mkParamName = () =>
+            val index = seenContextBounds + 1 // Start at 1 like FreshNameCreator.
+            val ret = ContextBoundParamName(EmptyTermName, index)
+            seenContextBounds += 1
+            ret,
+          forPrimaryConstructor = isPrimaryConstructor)
         tbounds
       case LambdaTypeTree(tparams, body) =>
         cpy.LambdaTypeTree(rhs)(tparams, desugarContextBounds(body))
       case _ =>
         rhs
-
     val paramssNoContextBounds =
       mapParamss(paramss) {
         tparam => cpy.TypeDef(tparam)(rhs = desugarContextBounds(tparam.rhs))
@@ -381,11 +395,14 @@ object desugar {
     tree match
       case untpd.Block(stats, expr) =>
         val (untpdTypeVariables, otherStats) = stats.span {
-          case tdef @ untpd.TypeDef(name, _) => name.isVarPattern
+          case tdef @ untpd.TypeDef(name, _) => !tdef.isBackquoted && name.isVarPattern
           case _ => false
         }
+        val untpdCaseTypeVariables = untpdTypeVariables.asInstanceOf[List[untpd.TypeDef]].map {
+          tdef => tdef.withMods(tdef.mods | Case)
+        }
         val pattern = if otherStats.isEmpty then expr else untpd.cpy.Block(tree)(otherStats, expr)
-        (untpdTypeVariables.asInstanceOf[List[untpd.TypeDef]], pattern)
+        (untpdCaseTypeVariables, pattern)
       case _ =>
         (Nil, tree)
 
@@ -406,11 +423,11 @@ object desugar {
             meth.paramss :+ evidenceParams
         cpy.DefDef(meth)(paramss = paramss1)
 
-  /** The implicit evidence parameters of `meth`, as generated by `desugar.defDef` */
+  /** The parameters generated from the contextual bounds of `meth`, as generated by `desugar.defDef` */
   private def evidenceParams(meth: DefDef)(using Context): List[ValDef] =
     meth.paramss.reverse match {
       case ValDefs(vparams @ (vparam :: _)) :: _ if vparam.mods.isOneOf(GivenOrImplicit) =>
-        vparams.takeWhile(_.name.is(EvidenceParamName))
+        vparams.takeWhile(_.name.is(ContextBoundParamName))
       case _ =>
         Nil
     }
@@ -1014,7 +1031,7 @@ object desugar {
    *  if the type has a pattern variable name
    */
   def quotedPatternTypeDef(tree: TypeDef)(using Context): TypeDef = {
-    assert(ctx.mode.is(Mode.QuotedPattern))
+    assert(ctx.mode.isQuotedPattern)
     if tree.name.isVarPattern && !tree.isBackquoted then
       val patternTypeAnnot = New(ref(defn.QuotedRuntimePatterns_patternTypeAnnot.typeRef)).withSpan(tree.span)
       val mods = tree.mods.withAddedAnnotation(patternTypeAnnot)
@@ -1083,19 +1100,21 @@ object desugar {
    */
   def makePolyFunctionType(tree: PolyFunction)(using Context): RefinedTypeTree =
     val PolyFunction(tparams: List[untpd.TypeDef] @unchecked, fun @ untpd.Function(vparamTypes, res)) = tree: @unchecked
-    val funFlags = fun match
+    val paramFlags = fun match
       case fun: FunctionWithMods =>
-        fun.mods.flags
-      case _ => EmptyFlags
+        // TODO: make use of this in the desugaring when pureFuns is enabled.
+        // val isImpure = funFlags.is(Impure)
 
-    // TODO: make use of this in the desugaring when pureFuns is enabled.
-    // val isImpure = funFlags.is(Impure)
+        // Function flags to be propagated to each parameter in the desugared method type.
+        val givenFlag = fun.mods.flags.toTermFlags & Given
+        fun.erasedParams.map(isErased => if isErased then givenFlag | Erased else givenFlag)
+      case _ =>
+        vparamTypes.map(_ => EmptyFlags)
 
-    // Function flags to be propagated to each parameter in the desugared method type.
-    val paramFlags = funFlags.toTermFlags & Given
-    val vparams = vparamTypes.zipWithIndex.map:
-      case (p: ValDef, _) => p.withAddedFlags(paramFlags)
-      case (p, n) => makeSyntheticParameter(n + 1, p).withAddedFlags(paramFlags)
+    val vparams = vparamTypes.lazyZip(paramFlags).zipWithIndex.map {
+      case ((p: ValDef, paramFlags), n) => p.withAddedFlags(paramFlags)
+      case ((p, paramFlags), n) => makeSyntheticParameter(n + 1, p).withAddedFlags(paramFlags)
+    }.toList
 
     RefinedTypeTree(ref(defn.PolyFunctionType), List(
        DefDef(nme.apply, tparams :: vparams :: Nil, res, EmptyTree).withFlags(Synthetic)
@@ -1363,7 +1382,7 @@ object desugar {
       case tree: ValDef => valDef(tree)
       case tree: TypeDef =>
         if (tree.isClassDef) classDef(tree)
-        else if (ctx.mode.is(Mode.QuotedPattern)) quotedPatternTypeDef(tree)
+        else if (ctx.mode.isQuotedPattern) quotedPatternTypeDef(tree)
         else tree
       case tree: DefDef =>
         if (tree.name.isConstructorName) tree // was already handled by enclosing classDef
@@ -1585,7 +1604,7 @@ object desugar {
 
   def makeContextualFunction(formals: List[Tree], body: Tree, erasedParams: List[Boolean])(using Context): Function = {
     val mods = Given
-    val params = makeImplicitParameters(formals, mods)
+    val params = makeImplicitParameters(formals, mods, mkParamName = () => ContextFunctionParamName.fresh())
     FunctionWithMods(params, body, Modifiers(mods), erasedParams)
   }
 

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

@@ -15,6 +15,12 @@ import config.Feature
 private val Captures: Key[CaptureSet] = Key()
 private val BoxedType: Key[BoxedTypeCache] = Key()
 
+/** Switch whether unpickled function types and byname types should be mapped to
+ *  impure types. With the new gradual typing using Fluid capture sets, this should
+ *  be no longer needed. Also, it has bad interactions with pickling tests.
+ */
+private val adaptUnpickledFunctionTypes = false
+
 /** The arguments of a @retains or @retainsByName annotation */
 private[cc] def retainedElems(tree: Tree)(using Context): List[Tree] = tree match
   case Apply(_, Typed(SeqLiteral(elems, _), _) :: Nil) => elems
@@ -49,7 +55,7 @@ extension (tree: Tree)
    *  a by name parameter type, turning the latter into an impure by name parameter type.
    */
   def adaptByNameArgUnderPureFuns(using Context): Tree =
-    if Feature.pureFunsEnabledSomewhere then
+    if adaptUnpickledFunctionTypes && Feature.pureFunsEnabledSomewhere then
       val rbn = defn.RetainsByNameAnnot
       Annotated(tree,
         New(rbn.typeRef).select(rbn.primaryConstructor).appliedTo(
@@ -145,7 +151,7 @@ extension (tp: Type)
    */
   def adaptFunctionTypeUnderPureFuns(using Context): Type = tp match
     case AppliedType(fn, args)
-    if Feature.pureFunsEnabledSomewhere && defn.isFunctionClass(fn.typeSymbol) =>
+    if adaptUnpickledFunctionTypes && Feature.pureFunsEnabledSomewhere && defn.isFunctionClass(fn.typeSymbol) =>
       val fname = fn.typeSymbol.name
       defn.FunctionType(
         fname.functionArity,

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

@@ -356,6 +356,20 @@ object CaptureSet:
     override def toString = elems.toString
   end Const
 
+  /** A special capture set that gets added to the types of symbols that were not
+   *  themselves capture checked, in order to admit arbitrary corresponding capture
+   *  sets in subcapturing comparisons. Similar to platform types for explicit
+   *  nulls, this provides more lenient checking against compilation units that
+   *  were not yet compiled with capture checking on.
+   */
+  object Fluid extends Const(emptySet):
+    override def isAlwaysEmpty = false
+    override def addNewElems(elems: Refs, origin: CaptureSet)(using Context, VarState) = CompareResult.OK
+    override def accountsFor(x: CaptureRef)(using Context): Boolean = true
+    override def mightAccountFor(x: CaptureRef)(using Context): Boolean = true
+    override def toString = "<fluid>"
+  end Fluid
+
   /** The subclass of captureset variables with given initial elements */
   class Var(initialElems: Refs = emptySet) extends CaptureSet:
 
@@ -863,7 +877,7 @@ object CaptureSet:
         case CapturingType(parent, refs) =>
           recur(parent) ++ refs
         case tpd @ RefinedType(parent, _, rinfo: MethodType)
-        if followResult && defn.isFunctionType(tpd) =>
+        if followResult && defn.isFunctionNType(tpd) =>
           ofType(parent, followResult = false)                 // pick up capture set from parent type
           ++ (recur(rinfo.resType)                             // add capture set of result
           -- CaptureSet(rinfo.paramRefs.filter(_.isTracked)*)) // but disregard bound parameters

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

@@ -290,14 +290,46 @@ class CheckCaptures extends Recheck, SymTransformer:
     def includeCallCaptures(sym: Symbol, pos: SrcPos)(using Context): Unit =
       if sym.exists && curEnv.isOpen then markFree(capturedVars(sym), pos)
 
+    private def handleBackwardsCompat(tp: Type, sym: Symbol, initialVariance: Int = 1)(using Context): Type =
+      val fluidify = new TypeMap with IdempotentCaptRefMap:
+        variance = initialVariance
+        def apply(t: Type): Type = t match
+          case t: MethodType =>
+            mapOver(t)
+          case t: TypeLambda =>
+            t.derivedLambdaType(resType = this(t.resType))
+          case CapturingType(_, _) =>
+            t
+          case _ =>
+            val t1  = t match
+              case t @ RefinedType(parent, rname, rinfo: MethodType) if defn.isFunctionType(t) =>
+                t.derivedRefinedType(parent, rname, this(rinfo))
+              case _ =>
+                mapOver(t)
+            if variance > 0 then t1
+            else Setup.decorate(t1, Function.const(CaptureSet.Fluid))
+
+      def isPreCC(sym: Symbol): Boolean =
+        sym.isTerm && sym.maybeOwner.isClass
+        && !sym.owner.is(CaptureChecked)
+        && !defn.isFunctionSymbol(sym.owner)
+
+      if isPreCC(sym) then
+        val tpw = tp.widen
+        val fluidTp = fluidify(tpw)
+        if fluidTp eq tpw then tp
+        else fluidTp.showing(i"fluid for ${sym.showLocated}, ${sym.is(JavaDefined)}: $tp --> $result", capt)
+      else tp
+    end handleBackwardsCompat
+
     override def recheckIdent(tree: Ident)(using Context): Type =
       if tree.symbol.is(Method) then
         if tree.symbol.info.isParameterless then
           // there won't be an apply; need to include call captures now
           includeCallCaptures(tree.symbol, tree.srcPos)
       else
         markFree(tree.symbol, tree.srcPos)
-      super.recheckIdent(tree)
+      handleBackwardsCompat(super.recheckIdent(tree), tree.symbol)
 
     /** A specialized implementation of the selection rule.
      *
@@ -327,7 +359,7 @@ class CheckCaptures extends Recheck, SymTransformer:
       val selType = recheckSelection(tree, qualType, name, disambiguate)
       val selCs = selType.widen.captureSet
       if selCs.isAlwaysEmpty || selType.widen.isBoxedCapturing || qualType.isBoxedCapturing then
-        selType
+        handleBackwardsCompat(selType, tree.symbol)
       else
         val qualCs = qualType.captureSet
         capt.println(i"pick one of $qualType, ${selType.widen}, $qualCs, $selCs in $tree")
@@ -362,7 +394,16 @@ class CheckCaptures extends Recheck, SymTransformer:
         val argType0 = f(recheckStart(arg, pt))
         val argType = super.recheckFinish(argType0, arg, pt)
         super.recheckFinish(argType, tree, pt)
-      if meth == defn.Caps_unsafeBox then
+
+      if meth == defn.Caps_unsafeAssumePure then
+        val arg :: Nil = tree.args: @unchecked
+        val argType0 = recheck(arg, pt.capturing(CaptureSet.universal))
+        val argType =
+          if argType0.captureSet.isAlwaysEmpty then argType0
+          else argType0.widen.stripCapturing
+        capt.println(i"rechecking $arg with ${pt.capturing(CaptureSet.universal)}: $argType")
+        super.recheckFinish(argType, tree, pt)
+      else if meth == defn.Caps_unsafeBox then
         mapArgUsing(_.forceBoxStatus(true))
       else if meth == defn.Caps_unsafeUnbox then
         mapArgUsing(_.forceBoxStatus(false))
@@ -662,8 +703,10 @@ class CheckCaptures extends Recheck, SymTransformer:
     /** Turn `expected` into a dependent function when `actual` is dependent. */
     private def alignDependentFunction(expected: Type, actual: Type)(using Context): Type =
       def recur(expected: Type): Type = expected.dealias match
-        case expected @ CapturingType(eparent, refs) =>
-          CapturingType(recur(eparent), refs, boxed = expected.isBoxed)
+        case expected0 @ CapturingType(eparent, refs) =>
+          val eparent1 = recur(eparent)
+          if eparent1 eq eparent then expected
+          else CapturingType(eparent1, refs, boxed = expected0.isBoxed)
         case expected @ defn.FunctionOf(args, resultType, isContextual)
           if defn.isNonRefinedFunction(expected) && defn.isFunctionNType(actual) && !defn.isNonRefinedFunction(actual) =>
           val expected1 = toDepFun(args, resultType, isContextual)
@@ -883,7 +926,7 @@ class CheckCaptures extends Recheck, SymTransformer:
     *  But maybe we can then elide the check during the RefChecks phase under captureChecking?
     */
     def checkOverrides = new TreeTraverser:
-      class OverridingPairsCheckerCC(clazz: ClassSymbol, self: Type, srcPos: SrcPos)(using Context) extends OverridingPairsChecker(clazz, self) {
+      class OverridingPairsCheckerCC(clazz: ClassSymbol, self: Type, srcPos: SrcPos)(using Context) extends OverridingPairsChecker(clazz, self):
         /** Check subtype with box adaptation.
         *  This function is passed to RefChecks to check the compatibility of overriding pairs.
         *  @param sym  symbol of the field definition that is being checked
@@ -905,7 +948,11 @@ class CheckCaptures extends Recheck, SymTransformer:
                 case _ => adapted
             finally curEnv = saved
           actual1 frozen_<:< expected1
-      }
+
+        override def adjustInfo(tp: Type, member: Symbol)(using Context): Type =
+          handleBackwardsCompat(tp, member, initialVariance = 0)
+            //.showing(i"adjust $other: $tp --> $result")
+      end OverridingPairsCheckerCC
 
       def traverse(t: Tree)(using Context) =
         t match