Backport "Port pc find references from metals" to LTS (#21144)

Backports #20544 to the LTS branch.

PR submitted by the release tooling.
[skip ci]

presentation-compiler/src/main/dotty/tools/pc/PcDocumentHighlightProvider.scala

@@ -14,7 +14,7 @@ import org.eclipse.lsp4j.DocumentHighlightKind
 final class PcDocumentHighlightProvider(
     driver: InteractiveDriver,
     params: OffsetParams
-) extends PcCollector[DocumentHighlight](driver, params):
+) extends WithSymbolSearchCollector[DocumentHighlight](driver, params):
 
   def collect(
       parent: Option[Tree]

presentation-compiler/src/main/dotty/tools/pc/PcInlineValueProviderImpl.scala

@@ -22,9 +22,9 @@ import dotty.tools.pc.utils.InteractiveEnrichments.*
 import org.eclipse.lsp4j as l
 
 final class PcInlineValueProviderImpl(
-    val driver: InteractiveDriver,
+    driver: InteractiveDriver,
     val params: OffsetParams
-) extends PcCollector[Option[Occurence]](driver, params)
+) extends WithSymbolSearchCollector[Option[Occurence]](driver, params)
     with InlineValueProvider:
 
   val position: l.Position = pos.toLsp.getStart().nn

presentation-compiler/src/main/dotty/tools/pc/PcReferencesProvider.scala

@@ -0,0 +1,67 @@
+package dotty.tools.pc
+
+import scala.language.unsafeNulls
+
+import scala.jdk.CollectionConverters.*
+
+import scala.meta.internal.metals.CompilerOffsetParams
+import scala.meta.pc.ReferencesRequest
+import scala.meta.pc.ReferencesResult
+
+import dotty.tools.dotc.ast.tpd
+import dotty.tools.dotc.ast.tpd.*
+import dotty.tools.dotc.core.Symbols.*
+import dotty.tools.dotc.interactive.InteractiveDriver
+import dotty.tools.dotc.util.SourcePosition
+import org.eclipse.lsp4j
+import org.eclipse.lsp4j.Location
+import dotty.tools.pc.utils.InteractiveEnrichments.*
+import scala.meta.internal.pc.PcReferencesResult
+
+class PcReferencesProvider(
+    driver: InteractiveDriver,
+    request: ReferencesRequest,
+) extends WithCompilationUnit(driver, request.file()) with PcCollector[Option[(String, Option[lsp4j.Range])]]:
+
+  private def soughtSymbols =
+    if(request.offsetOrSymbol().isLeft()) {
+      val offsetParams = CompilerOffsetParams(
+        request.file().uri(),
+        request.file().text(),
+        request.offsetOrSymbol().getLeft()
+      )
+      val symbolSearch = new WithCompilationUnit(driver, offsetParams) with PcSymbolSearch
+      symbolSearch.soughtSymbols.map(_._1)
+    } else {
+      SymbolProvider.compilerSymbol(request.offsetOrSymbol().getRight()).map(symbolAlternatives(_))
+    }
+
+  def collect(parent: Option[Tree])(
+      tree: Tree | EndMarker,
+      toAdjust: SourcePosition,
+      symbol: Option[Symbol],
+  ): Option[(String, Option[lsp4j.Range])] =
+    val (pos, _) = toAdjust.adjust(text)
+    tree match
+      case t: DefTree if !request.includeDefinition() =>
+        val sym = symbol.getOrElse(t.symbol)
+        Some(SemanticdbSymbols.symbolName(sym), None)
+      case t: Tree =>
+        val sym = symbol.getOrElse(t.symbol)
+        Some(SemanticdbSymbols.symbolName(sym), Some(pos.toLsp))
+      case _ => None
+
+  def references(): List[ReferencesResult] =
+    soughtSymbols match
+      case Some(sought) if sought.nonEmpty =>
+        resultWithSought(sought)
+        .flatten
+        .groupMap(_._1) { case (_, optRange) =>
+          optRange.map(new Location(request.file().uri().toString(), _))
+        }
+        .map { case (symbol, locs) =>
+          PcReferencesResult(symbol, locs.flatten.asJava)
+        }
+        .toList
+      case _ => Nil
+end PcReferencesProvider

presentation-compiler/src/main/dotty/tools/pc/PcRenameProvider.scala

@@ -16,7 +16,7 @@ final class PcRenameProvider(
     driver: InteractiveDriver,
     params: OffsetParams,
     name: Option[String]
-) extends PcCollector[l.TextEdit](driver, params):
+) extends WithSymbolSearchCollector[l.TextEdit](driver, params):
   private val forbiddenMethods =
     Set("equals", "hashCode", "unapply", "unary_!", "!")
   def canRenameSymbol(sym: Symbol)(using Context): Boolean =
@@ -25,7 +25,7 @@ final class PcRenameProvider(
         || sym.source.path.isWorksheet)
 
   def prepareRename(): Option[l.Range] =
-    soughtSymbols(path).flatMap((symbols, pos) =>
+    soughtSymbols.flatMap((symbols, pos) =>
       if symbols.forall(canRenameSymbol) then Some(pos.toLsp)
       else None
     )
@@ -42,13 +42,10 @@ final class PcRenameProvider(
     )
   end collect
 
-  def rename(
-  ): List[l.TextEdit] =
-    val (symbols, _) = soughtSymbols(path).getOrElse(Set.empty, pos)
+  def rename(): List[l.TextEdit] =
+    val (symbols, _) = soughtSymbols.getOrElse(Set.empty, pos)
     if symbols.nonEmpty && symbols.forall(canRenameSymbol(_))
-    then
-      val res = result()
-      res
+    then result()
     else Nil
   end rename
 end PcRenameProvider

presentation-compiler/src/main/dotty/tools/pc/PcSemanticTokensProvider.scala

@@ -60,7 +60,7 @@ final class PcSemanticTokensProvider(
         case _ => !df.rhs.isEmpty
     case _ => false
 
-  object Collector extends PcCollector[Option[Node]](driver, params):
+  object Collector extends SimpleCollector[Option[Node]](driver, params):
     override def collect(
         parent: Option[Tree]
     )(tree: Tree | EndMarker, pos: SourcePosition, symbol: Option[Symbol]): Option[Node] =