Merge pull request #12979 from dotty-staging/fix-12949

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

@@ -783,7 +783,7 @@ object desugar {
         DefDef(
           className.toTermName, joinParams(constrTparams, defParamss),
           classTypeRef, creatorExpr)
-          .withMods(companionMods | mods.flags.toTermFlags & GivenOrImplicit | Synthetic | Final)
+          .withMods(companionMods | mods.flags.toTermFlags & GivenOrImplicit | Final)
           .withSpan(cdef.span) :: Nil
       }
 
@@ -809,7 +809,7 @@ object desugar {
             Nil
         }
       }
-      val classMods = if mods.is(Given) then mods &~ Given | Synthetic else mods
+      val classMods = if mods.is(Given) then mods | Synthetic else mods
       cpy.TypeDef(cdef: TypeDef)(
         name = className,
         rhs = cpy.Template(impl)(constr, parents1, clsDerived, self1,

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

@@ -63,7 +63,7 @@ class TreeMapWithImplicits extends tpd.TreeMap {
   private def nestedScopeCtx(defs: List[Tree])(using Context): Context = {
     val nestedCtx = ctx.fresh.setNewScope
     defs foreach {
-      case d: DefTree if d.symbol.isOneOf(GivenOrImplicit) => nestedCtx.enter(d.symbol)
+      case d: DefTree if d.symbol.isOneOf(GivenOrImplicitVal) => nestedCtx.enter(d.symbol)
       case _ =>
     }
     nestedCtx
@@ -74,7 +74,7 @@ class TreeMapWithImplicits extends tpd.TreeMap {
     new TreeTraverser {
       def traverse(tree: Tree)(using Context): Unit = {
         tree match {
-          case d: DefTree if d.symbol.isOneOf(GivenOrImplicit) =>
+          case d: DefTree if d.symbol.isOneOf(GivenOrImplicitVal) =>
             nestedCtx.enter(d.symbol)
           case _ =>
         }

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -13,7 +13,6 @@ import Scopes._
 import Uniques._
 import ast.Trees._
 import ast.untpd
-import Flags.GivenOrImplicit
 import util.{NoSource, SimpleIdentityMap, SourceFile, HashSet, ReusableInstance}
 import typer.{Implicits, ImportInfo, Inliner, SearchHistory, SearchRoot, TypeAssigner, Typer, Nullables}
 import Nullables._

compiler/src/dotty/tools/dotc/core/Flags.scala

@@ -233,7 +233,7 @@ object Flags {
   val (Param @ _, TermParam @ _, TypeParam @ _) = newFlags(8, "<param>")
 
   /** Labeled with `implicit` modifier (implicit value) */
-  val (Implicit @ _, ImplicitTerm @ _, _) = newFlags(9, "implicit")
+  val (Implicit @ _, ImplicitVal @ _, _) = newFlags(9, "implicit")
 
   /** Labeled with `lazy` (a lazy val) / a trait */
   val (LazyOrTrait @ _, Lazy @ _, Trait @ _) = newFlags(10, "lazy", "<trait>")
@@ -321,7 +321,7 @@ object Flags {
   val (Extension @ _, ExtensionMethod @ _, _) = newFlags(28, "<extension>")
 
   /** An inferable (`given`) parameter */
-  val (Given @ _, _, _) = newFlags(29, "given")
+  val (Given @ _, GivenVal @ _,  _) = newFlags(29, "given")
 
   /** Symbol is defined by a Java class */
   val (JavaDefined @ _, JavaDefinedVal @ _, _) = newFlags(30, "<java>")
@@ -568,6 +568,7 @@ object Flags {
   val FinalOrSealed: FlagSet                 = Final | Sealed
   val GivenOrImplicit: FlagSet               = Given | Implicit
   val GivenOrImplicitVal: FlagSet            = GivenOrImplicit.toTermFlags
+  val GivenMethod: FlagSet                   = Given | Method
   val InlineOrProxy: FlagSet                 = Inline | InlineProxy                           // An inline method or inline argument proxy */
   val InlineMethod: FlagSet                  = Inline | Method
   val InlineParam: FlagSet                   = Inline | Param
@@ -600,7 +601,6 @@ object Flags {
   val Scala2Trait: FlagSet                   = Scala2x | Trait
   val SyntheticArtifact: FlagSet             = Synthetic | Artifact
   val SyntheticCase: FlagSet                 = Synthetic | Case
-  val SyntheticGivenMethod: FlagSet          = Synthetic | Given | Method
   val SyntheticModule: FlagSet               = Synthetic | Module
   val SyntheticOpaque: FlagSet               = Synthetic | Opaque
   val SyntheticParam: FlagSet                = Synthetic | Param

compiler/src/dotty/tools/dotc/core/Scopes.scala

@@ -411,7 +411,7 @@ object Scopes {
       var irefs = new mutable.ListBuffer[TermRef]
       var e = lastEntry
       while (e ne null) {
-        if (e.sym.isOneOf(GivenOrImplicit)) {
+        if (e.sym.isOneOf(GivenOrImplicitVal)) {
           val d = e.sym.denot
           irefs += TermRef(NoPrefix, d.symbol.asTerm).withDenot(d)
         }

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -711,6 +711,19 @@ object SymDenotations {
          }
       )
 
+    /** Do this symbol and `cls` represent a pair of a given or implicit method and
+     *  its associated class that were defined by a single definition?
+     *  This can mean one of two things:
+     *   - the method and class are defined in a structural given instance, or
+     *   - the class is an implicit class and the method is its implicit conversion.
+	 */
+    final def isCoDefinedGiven(cls: Symbol)(using Context): Boolean =
+      is(Method) && isOneOf(GivenOrImplicit)
+      && ( is(Synthetic)                 // previous scheme used in 3.0
+         || cls.isOneOf(GivenOrImplicit) // new scheme from 3.1
+         )
+      && name == cls.name.toTermName && owner == cls.owner
+
     /** Is this a denotation of a stable term (or an arbitrary type)?
       * Terms are stable if they are idempotent (as in TreeInfo.Idempotent): that is, they always return the same value,
       * if any.
@@ -2231,7 +2244,7 @@ object SymDenotations {
           if (keepOnly eq implicitFilter)
             if (this.is(Package)) Iterator.empty
               // implicits in package objects are added by the overriding `memberNames` in `PackageClassDenotation`
-            else info.decls.iterator.filter(_.isOneOf(GivenOrImplicit))
+            else info.decls.iterator.filter(_.isOneOf(GivenOrImplicitVal))
           else info.decls.iterator
         for (sym <- ownSyms) maybeAdd(sym.name)
         names

compiler/src/dotty/tools/dotc/core/TypeErrors.scala

@@ -141,7 +141,7 @@ class CyclicReference private (val denot: SymDenotation) extends TypeError {
         }
 
       // Give up and give generic errors.
-      else if (cycleSym.isOneOf(GivenOrImplicit, butNot = Method) && cycleSym.owner.isTerm)
+      else if (cycleSym.isOneOf(GivenOrImplicitVal, butNot = Method) && cycleSym.owner.isTerm)
         CyclicReferenceInvolvingImplicit(cycleSym)
       else
         CyclicReferenceInvolving(denot)

compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala

@@ -722,9 +722,9 @@ class TreePickler(pickler: TastyPickler) {
     if flags.is(Invisible) then writeModTag(INVISIBLE)
     if (flags.is(Erased)) writeModTag(ERASED)
     if (flags.is(Exported)) writeModTag(EXPORTED)
+    if (flags.is(Given)) writeModTag(GIVEN)
+    if (flags.is(Implicit)) writeModTag(IMPLICIT)
     if (isTerm) {
-      if (flags.is(Implicit)) writeModTag(IMPLICIT)
-      if (flags.is(Given)) writeModTag(GIVEN)
       if (flags.is(Lazy, butNot = Module)) writeModTag(LAZY)
       if (flags.is(AbsOverride)) { writeModTag(ABSTRACT); writeModTag(OVERRIDE) }
       if (flags.is(Mutable)) writeModTag(MUTABLE)

compiler/src/dotty/tools/dotc/interactive/Completion.scala

@@ -323,7 +323,7 @@ object Completion {
       val extMethodsFromImplicitScope = extractMemberExtensionMethods(implicitScopeCompanions)
 
       // 4. The reference is of the form r.m and the extension method is defined in some given instance in the implicit scope of the type of r.
-      val givensInImplicitScope = implicitScopeCompanions.flatMap(_.membersBasedOnFlags(required = Given, excluded = EmptyFlags)).map(_.info)
+      val givensInImplicitScope = implicitScopeCompanions.flatMap(_.membersBasedOnFlags(required = GivenVal, excluded = EmptyFlags)).map(_.info)
       val extMethodsFromGivensInImplicitScope = extractMemberExtensionMethods(givensInImplicitScope)
 
       val availableExtMethods = extMethodsFromGivensInImplicitScope ++ extMethodsFromImplicitScope ++ extMethodsFromGivensInScope ++ extMethodsInScope

compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala

@@ -79,6 +79,8 @@ class ExtractSemanticDB extends Phase:
       || sym.isLocalDummy
       || sym.is(Synthetic)
       || sym.isSetter
+      || sym.isOldStyleImplicitConversion(forImplicitClassOnly = true)
+      || sym.owner.isGivenInstanceSummoner
       || excludeDefOrUse(sym)
 
     private def excludeDefOrUse(sym: Symbol)(using Context): Boolean =
@@ -102,6 +104,7 @@ class ExtractSemanticDB extends Phase:
     private def excludeChildren(sym: Symbol)(using Context): Boolean =
       !sym.exists
       || sym.is(Param) && sym.info.bounds.hi.isInstanceOf[Types.HKTypeLambda]
+      || sym.isOldStyleImplicitConversion(forImplicitClassOnly = true)
 
     /** Uses of this symbol where the reference has given span should be excluded from semanticdb */
     private def excludeUse(qualifier: Option[Symbol], sym: Symbol)(using Context): Boolean =

compiler/src/dotty/tools/dotc/semanticdb/Tools.scala

@@ -41,6 +41,11 @@ object Tools:
         document.copy(text = text)
   end loadTextDocument
 
+  def loadTextDocumentUnsafe(scalaAbsolutePath: Path, semanticdbAbsolutePath: Path): TextDocument =
+    val docs = parseTextDocuments(semanticdbAbsolutePath).documents
+    assert(docs.length == 1)
+    docs.head.copy(text = new String(Files.readAllBytes(scalaAbsolutePath), StandardCharsets.UTF_8))
+
   /** Parses SemanticDB text documents from an absolute path to a `*.semanticdb` file. */
   private def parseTextDocuments(path: Path): TextDocuments =
     val bytes = Files.readAllBytes(path) // NOTE: a semanticdb file is a TextDocuments message, not TextDocument

compiler/src/dotty/tools/dotc/transform/SymUtils.scala

@@ -87,6 +87,31 @@ object SymUtils:
 
     def isGenericProduct(using Context): Boolean = whyNotGenericProduct.isEmpty
 
+    /** Is this an old style implicit conversion?
+     *  @param directOnly            only consider explicitly written methods
+     *  @param forImplicitClassOnly  only consider methods generated from implicit classes
+     */
+    def isOldStyleImplicitConversion(directOnly: Boolean = false, forImplicitClassOnly: Boolean = false)(using Context): Boolean =
+      self.is(Implicit) && self.info.stripPoly.match
+        case mt @ MethodType(_ :: Nil) if !mt.isImplicitMethod =>
+          if self.isCoDefinedGiven(mt.finalResultType.typeSymbol)
+          then !directOnly
+          else !forImplicitClassOnly
+        case _ =>
+          false
+
+    /** Is this the method that summons a structural given instance? */
+    def isGivenInstanceSummoner(using Context): Boolean =
+      def isCodefined(info: Type): Boolean = info.stripPoly match
+        case mt: MethodType =>
+          // given summoner can only have contextual params
+          mt.isImplicitMethod && isCodefined(mt.resultType)
+        case mt: ExprType =>
+          isCodefined(mt.resultType)
+        case res =>
+          self.isCoDefinedGiven(res.typeSymbol)
+      self.isAllOf(Given | Method) && isCodefined(self.info)
+
     def useCompanionAsMirror(using Context): Boolean = self.linkedClass.exists && !self.is(Scala2x)
 
     /** Is this a sealed class or trait for which a sum mirror is generated?

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -1631,7 +1631,7 @@ trait Applications extends Compatibility {
     /** Widen the result type of synthetic given methods from the implementation class to the
      *  type that's implemented. Example
      *
-     *      given I[X] as T { ... }
+     *      given I[X]: T with { ... }
      *
      *  This desugars to
      *
@@ -1641,7 +1641,7 @@ trait Applications extends Compatibility {
      *  To compare specificity we should compare with `T`, not with its implementation `I[X]`.
      *  No such widening is performed for given aliases, which are not synthetic. E.g.
      *
-     *      given J[X] as T = rhs
+     *      given J[X]: T = rhs
      *
      *  already has the right result type `T`. Neither is widening performed for given
      *  objects, since these are anyway taken to be more specific than methods
@@ -1652,8 +1652,8 @@ trait Applications extends Compatibility {
         mt.derivedLambdaType(mt.paramNames, mt.paramInfos, widenGiven(mt.resultType, alt))
       case pt: PolyType =>
         pt.derivedLambdaType(pt.paramNames, pt.paramInfos, widenGiven(pt.resultType, alt))
-      case _ =>
-        if (alt.symbol.isAllOf(SyntheticGivenMethod)) tp.widenToParents
+      case rt =>
+        if alt.symbol.isCoDefinedGiven(rt.typeSymbol) then tp.widenToParents
         else tp
     }
 

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -473,7 +473,7 @@ object Checking {
     if (sym.is(Implicit)) {
       if (sym.owner.is(Package))
         fail(TopLevelCantBeImplicit(sym))
-      if (sym.isType)
+      if sym.isType && (!sym.isClass || sym.is(Trait)) then
         fail(TypesAndTraitsCantBeImplicit())
     }
     if sym.is(Transparent) then
@@ -861,22 +861,14 @@ trait Checking {
   /** If `sym` is an old-style implicit conversion, check that implicit conversions are enabled.
    *  @pre  sym.is(GivenOrImplicit)
    */
-  def checkImplicitConversionDefOK(sym: Symbol)(using Context): Unit = {
-    def check(): Unit =
+  def checkImplicitConversionDefOK(sym: Symbol)(using Context): Unit =
+    if sym.isOldStyleImplicitConversion(directOnly = true) then
       checkFeature(
         nme.implicitConversions,
         i"Definition of implicit conversion $sym",
         ctx.owner.topLevelClass,
         sym.srcPos)
 
-    sym.info.stripPoly match {
-      case mt @ MethodType(_ :: Nil)
-      if !mt.isImplicitMethod && !sym.is(Synthetic) => // it's an old-styleconversion
-        check()
-      case _ =>
-    }
-  }
-
   /** If `tree` is an application of a new-style implicit conversion (using the apply
    *  method of a `scala.Conversion` instance), check that implicit conversions are
    *  enabled.

compiler/src/dotty/tools/dotc/typer/ImportInfo.scala

@@ -151,7 +151,7 @@ class ImportInfo(symf: Context ?=> Symbol,
     else
       for
         renamed <- reverseMapping.keys
-        denot <- pre.member(reverseMapping(renamed)).altsWith(_.isOneOf(GivenOrImplicit))
+        denot <- pre.member(reverseMapping(renamed)).altsWith(_.isOneOf(GivenOrImplicitVal))
       yield
         val original = reverseMapping(renamed)
         val ref = TermRef(pre, original, denot)

compiler/src/dotty/tools/dotc/typer/Namer.scala

@@ -241,7 +241,7 @@ class Namer { typer: Typer =>
 
     tree match {
       case tree: TypeDef if tree.isClassDef =>
-        val flags = checkFlags(tree.mods.flags &~ Implicit)
+        val flags = checkFlags(tree.mods.flags)
         val name = checkNoConflict(tree.name, flags.is(Private), tree.span).asTypeName
         val cls =
           createOrRefine[ClassSymbol](tree, name, flags, ctx.owner,

compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala

@@ -326,7 +326,7 @@ trait QuotesAndSplices {
           tdef.symbol.addAnnotation(Annotation(New(ref(defn.QuotedRuntimePatterns_fromAboveAnnot.typeRef)).withSpan(tdef.span)))
         val bindingType = getBinding(tdef.symbol).symbol.typeRef
         val bindingTypeTpe = AppliedType(defn.QuotedTypeClass.typeRef, bindingType :: Nil)
-        val sym = newPatternBoundSymbol(nameOfSyntheticGiven, bindingTypeTpe, tdef.span, flags = ImplicitTerm)(using ctx0)
+        val sym = newPatternBoundSymbol(nameOfSyntheticGiven, bindingTypeTpe, tdef.span, flags = ImplicitVal)(using ctx0)
         buff += Bind(sym, untpd.Ident(nme.WILDCARD).withType(bindingTypeTpe)).withSpan(tdef.span)
         super.transform(tdef)
       }

compiler/test-resources/repl/i1374

@@ -1,5 +1,6 @@
 scala> implicit class Padder(val sb: StringBuilder) extends AnyVal { def pad2(width: Int) = { 1 to width - sb.length foreach { sb append '*' }; sb } }
 // defined class Padder
+def Padder(sb: StringBuilder): Padder
 scala> val greeting = new StringBuilder("Hello, kitteh!")
 val greeting: StringBuilder = Hello, kitteh!
 scala> val a = greeting pad2 20

compiler/test/dotty/tools/dotc/semanticdb/SemanticdbTests.scala

@@ -25,6 +25,30 @@ import dotty.tools.dotc.util.SourceFile
 @main def updateExpect =
   SemanticdbTests().runExpectTest(updateExpectFiles = true)
 
+/** Useful for printing semanticdb metac output for one file
+ *
+ *  @param root the output directory containing semanticdb output,
+ *  only 1 semanticdb file should be present
+ *  @param source the single source file producing the semanticdb
+ */
+@main def metac(root: String, source: String) =
+  val rootSrc = Paths.get(root)
+  val sourceSrc = Paths.get(source)
+  val semanticFile = FileSystems.getDefault.getPathMatcher("glob:**.semanticdb")
+  def inputFile(): Path =
+    val ls = Files.walk(rootSrc.resolve("META-INF").resolve("semanticdb"))
+    val files =
+      try ls.filter(p => semanticFile.matches(p)).collect(Collectors.toList).asScala
+      finally ls.close()
+    require(files.sizeCompare(1) == 0, s"No semanticdb files! $rootSrc")
+    files.head
+  val metacSb: StringBuilder = StringBuilder(5000)
+  val semanticdbPath = inputFile()
+  val doc = Tools.loadTextDocumentUnsafe(sourceSrc.toAbsolutePath, semanticdbPath)
+  Tools.metac(doc, Paths.get(doc.uri))(using metacSb)
+  Files.write(rootSrc.resolve("metac.expect"), metacSb.toString.getBytes(StandardCharsets.UTF_8))
+
+
 @Category(Array(classOf[BootstrappedOnlyTests]))
 class SemanticdbTests:
   val javaFile = FileSystems.getDefault.getPathMatcher("glob:**.java")

tests/pos/i12949.scala

@@ -0,0 +1,19 @@
+object Catch22:
+  trait TC[V]
+  object TC:
+    export Hodor.TC.given
+
+object Hodor:
+  object TC:
+    import Catch22.TC
+    given fromString[V <: String]: TC[V] = ???
+    transparent inline given fromDouble[V <: Double]: TC[V] =
+      new TC[V]:
+        type Out = Double
+    given fromInt[V <: Int]: TC[V] with
+      type Out = Int
+
+object Test:
+  summon[Catch22.TC["hi"]] //works
+  summon[Catch22.TC[7.7]] //works
+  summon[Catch22.TC[1]] //error

tests/semanticdb/expect/InventedNames.expect.scala

@@ -39,4 +39,4 @@ val f/*<-givens::InventedNames$package.f.*/ = given_Float/*->givens::InventedNam
 val g/*<-givens::InventedNames$package.g.*/ = `* *`/*->givens::InventedNames$package.`* *`.*/
 val x/*<-givens::InventedNames$package.x.*/ = given_X/*->givens::InventedNames$package.given_X.*/
 val y/*<-givens::InventedNames$package.y.*/ = given_Y/*->givens::InventedNames$package.given_Y().*/
-val z/*<-givens::InventedNames$package.z.*/ = given_Z_T/*->givens::InventedNames$package.given_Z_T().*/[String/*->scala::Predef.String#*/]
+val z/*<-givens::InventedNames$package.z.*/ = given_Z_T/*->givens::InventedNames$package.given_Z_T().*/[String/*->scala::Predef.String#*/]

tests/semanticdb/expect/InventedNames.scala

@@ -39,4 +39,4 @@ val f = given_Float
 val g = `* *`
 val x = given_X
 val y = given_Y
-val z = given_Z_T[String]
+val z = given_Z_T[String]