Exclude implicit class conversions in SemanticDB

Conversions generated for implicit classes were synthetic before,
now they need to be excluded separately.

Author: odersky

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

@@ -79,6 +79,7 @@ class ExtractSemanticDB extends Phase:
       || sym.isLocalDummy
       || sym.is(Synthetic)
       || sym.isSetter
+      || sym.isOldStyleImplicitConversion(forImplicitClassOnly = true)
       || excludeDefOrUse(sym)
 
     private def excludeDefOrUse(sym: Symbol)(using Context): Boolean =
@@ -102,6 +103,7 @@ 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/transform/SymUtils.scala

@@ -87,6 +87,19 @@ object SymUtils:
 
     def isGenericProduct(using Context): Boolean = whyNotGenericProduct.isEmpty
 
+    /** Is this the 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
+
     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/Checking.scala

@@ -861,23 +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.isCoDefinedGiven(mt.finalResultType.typeSymbol) =>
-        // it's an old-style conversion
-        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.

tests/semanticdb/expect/InventedNames.expect.scala

@@ -25,7 +25,7 @@ given X/*->givens::X#*/ with
 given (using X/*->givens::X#*/): Y/*->givens::Y#*/ with
   def doY/*<-givens::InventedNames$package.given_Y#doY().*/ = "7"
 
-given [T/*<-givens::InventedNames$package.given_Z_T#[T]*/]: Z/*->givens::Z#*/[T/*->givens::InventedNames$package.given_Z_T#[T]*/] with
+given [T/*<-givens::InventedNames$package.given_Z_T#[T]*//*<-givens::InventedNames$package.given_Z_T().[T]*/]: Z/*->givens::Z#*/[T/*->givens::InventedNames$package.given_Z_T#[T]*/] with
   def doZ/*<-givens::InventedNames$package.given_Z_T#doZ().*/: List/*->scala::package.List#*/[T/*->givens::InventedNames$package.given_Z_T#[T]*/] = Nil/*->scala::package.Nil.*/
 
 

tests/semanticdb/metac.expect

@@ -1678,7 +1678,7 @@ Uri => InventedNames.scala
 Text => empty
 Language => Scala
 Symbols => 45 entries
-Occurrences => 61 entries
+Occurrences => 62 entries
 
 Symbols:
 givens/InventedNames$package. => final package object givens extends Object { self: givens.type => +24 decls }
@@ -1761,6 +1761,7 @@ Occurrences:
 [24:17..24:18): Y -> givens/Y#
 [25:6..25:9): doY <- givens/InventedNames$package.given_Y#doY().
 [27:7..27:8): T <- givens/InventedNames$package.given_Z_T#[T]
+[27:7..27:8): T <- givens/InventedNames$package.given_Z_T().[T]
 [27:11..27:12): Z -> givens/Z#
 [27:13..27:14): T -> givens/InventedNames$package.given_Z_T#[T]
 [28:6..28:9): doZ <- givens/InventedNames$package.given_Z_T#doZ().