avoid blacklisting scala.Predef and scala.StringContext

Simply check if prefix of a select has a range that is visible

Author: bishabosha

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

@@ -175,8 +175,6 @@ class ExtractSemanticDB extends Phase {
 
     private def blacklistPrefix(sym: Symbol)(given Context): Boolean =
       sym.is(Package)
-      || sym == defn.ScalaPredefModule
-      || sym == defn.StringContextModule
 
     private def (sym: Symbol) isAnonymous(given Context): Boolean =
       sym.isAnonymousClass
@@ -244,16 +242,17 @@ class ExtractSemanticDB extends Phase {
           if tree.name != nme.WILDCARD && !excludeUseStrict(tree.symbol, tree.span) then
             registerUse(tree.symbol, tree.span)
         case tree: Select =>
+          val qualSpan = tree.qualifier.span
           if !excludeUseStrict(tree.symbol, tree.span) then
             val end = tree.span.end
-            val limit = tree.qualifier.span.end
+            val limit = qualSpan.end
             val start =
               if limit < end then
                 val len = tree.name.toString.length
                 if source.content()(end - 1) == '`' then end - len - 1 else end - len
               else limit
             registerUse(tree.symbol, Span(start max limit, end))
-          if !blacklistPrefix(tree.qualifier.symbol) then
+          if !blacklistPrefix(tree.qualifier.symbol) && qualSpan.exists && qualSpan.start != qualSpan.end then
             traverseChildren(tree)
         case tree: Import =>
           if tree.span.exists && tree.span.start != tree.span.end then

tests/semanticdb/Advanced.expect.scala

@@ -26,7 +26,7 @@ object Test/*<<=advanced.Test.*/ {
   val s2/*<<=advanced.Test.s2.*/ = s/*=>>advanced.Test.s.*/.s2/*=>>advanced.Structural#s2().*/
   val s2x/*<<=advanced.Test.s2x.*/ = /*=>>scala.reflect.Selectable.reflectiveSelectable().*/s/*=>>advanced.Test.s.*/.s2/*=>>advanced.Structural#s2().*//*=>>scala.Selectable#selectDynamic().*/.x
   val s3/*<<=advanced.Test.s3.*/ = s/*=>>advanced.Test.s.*/.s3/*=>>advanced.Structural#s3().*/
-  val s3x/*<<=advanced.Test.s3x.*/ = /*=>>scala.reflect.Selectable.reflectiveSelectable().*/s/*=>>advanced.Test.s.*/.s3/*=>>advanced.Structural#s3().*//*=>>scala.Selectable#applyDynamic().*/.m/*=>>scala.reflect.ClassTag.apply().*//*=>>scala.reflect.ClassTag.*//*=>>java.lang.Integer.TYPE.*//*=>>java.lang.Integer.*/(???/*=>>scala.Predef.`???`().*/)
+  val s3x/*<<=advanced.Test.s3x.*/ = /*=>>scala.reflect.Selectable.reflectiveSelectable().*/s/*=>>advanced.Test.s.*/.s3/*=>>advanced.Structural#s3().*//*=>>scala.Selectable#applyDynamic().*/.m/*=>>scala.reflect.ClassTag.apply().*//*=>>java.lang.Integer.TYPE.*/(???/*=>>scala.Predef.`???`().*/)
 
   val e/*<<=advanced.Test.e.*/ = new Wildcards/*=>>advanced.Wildcards#*//*=>>advanced.Wildcards#`<init>`().*/
   val e1/*<<=advanced.Test.e1.*/ = e/*=>>advanced.Test.e.*/.e1/*=>>advanced.Wildcards#e1().*/

tests/semanticdb/Enums.expect.scala

@@ -14,7 +14,7 @@ object Enums/*<<=_empty_.Enums.*/ {
   }
 
   enum Maybe/*<<=_empty_.Enums.Maybe#*/[+A/*<<=_empty_.Enums.Maybe#[A]*/] {
-    /*=>>_empty_.Enums.Maybe#`<init>`().*//*=>>_empty_.Enums.Maybe.Just#[A]*/case Just/*<<=_empty_.Enums.Maybe.Just#*/(value/*<<=_empty_.Enums.Maybe.Just#value.*/: A/*=>>_empty_.Enums.Maybe.Just#`<init>`().[A]*/)
+    /*=>>_empty_.Enums.Maybe#`<init>`().*/case Just/*<<=_empty_.Enums.Maybe.Just#*/(value/*<<=_empty_.Enums.Maybe.Just#value.*/: A/*=>>_empty_.Enums.Maybe.Just#`<init>`().[A]*/)
     /*=>>_empty_.Enums.Maybe#`<init>`().*/case None/*<<=_empty_.Enums.Maybe.None.*/
   }
 

tests/semanticdb/Example.expect.scala

@@ -3,9 +3,9 @@ package example
 import scala.concurrent.Future/*=>>scala.concurrent.Future.*//*=>>scala.concurrent.Future#*/
 
 object Example/*<<=example.Example.*/ { /*=>>example.Example.*/self/*<<=local0*/ =>
-  new /*=>>scala.collection.mutable.Stack.*/scala.collection.mutable.Stack/*=>>scala.collection.mutable.Stack#*/[Int/*=>>scala.Int#*/]/*=>>scala.collection.mutable.Stack#`<init>`(+1).*/()
+  new scala.collection.mutable.Stack/*=>>scala.collection.mutable.Stack#*/[Int/*=>>scala.Int#*/]/*=>>scala.collection.mutable.Stack#`<init>`(+1).*/()
   def main/*<<=example.Example.main().*/(args/*<<=example.Example.main().(args)*/: Array/*=>>scala.Array#*/[String/*=>>scala.Predef.String#*/]): Unit/*=>>scala.Unit#*/ = {
     println/*=>>scala.Predef.println(+1).*/(1)
   }
-  val x/*<<=example.Example.x.*/ = scala.reflect.classTag/*=>>scala.reflect.package.classTag().*/[Int/*=>>scala.Int#*/]/*=>>scala.reflect.ClassTag.apply().*//*=>>scala.reflect.ClassTag.*//*=>>java.lang.Integer.TYPE.*//*=>>java.lang.Integer.*/
+  val x/*<<=example.Example.x.*/ = scala.reflect.classTag/*=>>scala.reflect.package.classTag().*/[Int/*=>>scala.Int#*/]/*=>>scala.reflect.ClassTag.apply().*//*=>>java.lang.Integer.TYPE.*/
 }

tests/semanticdb/Givens.expect.scala

@@ -6,7 +6,7 @@ object Givens/*<<=a.b.Givens.*/
   given :[A](any: A)
     de/*<<=a.b.Givens.given_sayHello_of_A.*//*<<=a.b.Givens.given_sayHello_of_A.sayHello().[A]*//*<<=a.b.Givens.given_sayHello_of_A.sayHello().(any)*//*=>>a.b.Givens.given_sayHello_of_A.sayHello().[A]*/f sayHello/*<<=a.b.Givens.given_sayHello_of_A.sayHello().*/ = s"Hello, I am $any/*=>>a.b.Givens.given_sayHello_of_A.sayHello().(any)*//*=>>scala.StringContext#s().*/"
 
-  val hello1/*<<=a.b.Givens.hello1.*/ = /*=>>a.b.Givens.given_sayHello_of_A.sayHello().*//*=>>a.b.Givens.given_sayHello_of_A.*/1.sayHello
+  val hello1/*<<=a.b.Givens.hello1.*/ = /*=>>a.b.Givens.given_sayHello_of_A.sayHello().*/1.sayHello
 
   trait Monoid/*<<=a.b.Givens.Monoid#*/[A/*<<=a.b.Givens.Monoid#[A]*/]
     def empty/*<<=a.b.Givens.Monoid#empty().*/: A/*=>>a.b.Givens.Monoid#[A]*/

tests/semanticdb/ImplicitConversion.expect.scala

@@ -8,7 +8,7 @@ class ImplicitConversion/*<<=example.ImplicitConversion#*/ {
   ): Int/*=>>scala.Int#*/ = 42
   implicit def newAny2StringAdd/*<<=example.ImplicitConversion#newAny2StringAdd().*/[T/*<<=example.ImplicitConversion#newAny2StringAdd().[T]*/](
       any/*<<=example.ImplicitConversion#newAny2StringAdd().(any)*/: T/*=>>example.ImplicitConversion#newAny2StringAdd().[T]*/
-  ): Predef.any2stringadd/*=>>scala.Predef.any2stringadd#*/[T/*=>>example.ImplicitConversion#newAny2StringAdd().[T]*/] = new Predef.any2stringadd/*=>>scala.Predef.any2stringadd#`<init>`().*/(any/*=>>example.ImplicitConversion#newAny2StringAdd().(any)*/)
+  ): Predef/*=>>scala.Predef.*/.any2stringadd/*=>>scala.Predef.any2stringadd#*/[T/*=>>example.ImplicitConversion#newAny2StringAdd().[T]*/] = new Predef/*=>>scala.Predef.*/.any2stringadd/*=>>scala.Predef.any2stringadd#`<init>`().*/(any/*=>>example.ImplicitConversion#newAny2StringAdd().(any)*/)
   val message/*<<=example.ImplicitConversion#message.*/ = ""
   val number/*<<=example.ImplicitConversion#number.*/ = 42
   val tuple/*<<=example.ImplicitConversion#tuple.*/ = (1, 2)

tests/semanticdb/todo renamed to tests/semanticdb/todo.md

@@ -8,9 +8,9 @@ This todolist is based upon blackbox observation of testcases at this repository
 - [ ] Hide calls to implicit conversions and their arguments
 - [ ] Hide Tuple contructors
 - [x] unescape unicode in names.
-- [x] Hide `scala.Predef` prefix
-- [x] Hide `scala.StringContext`
 - [x] Only traverse prefix of a Select if it is not a package
 - [x] Ensure only methods are counted in overloads
 - [x] Import wildcard needs to have reference to the qualifier
+- [-] ~~Hide `scala.Predef` prefix~~ // same effect acheved by ensuring prefix has a range > 0
+- [-] ~~Hide `scala.StringContext`~~ // same effect acheved by ensuring prefix has a range > 0
 - [-] ~~Hide `Predef.classOf`~~ // won't fix - confirmed as a bug in scalameta