support inlined local defs

Author: bishabosha

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

@@ -334,14 +334,16 @@ class ExtractSemanticDB extends Phase:
        *  the same starting position have the same index.
        */
       def localIdx(sym: Symbol)(using Context): Int =
+        def startPos(sym: Symbol) =
+          if sym.span.exists then sym.span.start else -1
         def computeLocalIdx(): Int =
-          symsAtOffset(sym.span.start).find(_.name == sym.name) match
+          symsAtOffset(startPos(sym)).find(_.name == sym.name) match
             case Some(other) => localIdx(other)
             case None =>
               val idx = nextLocalIdx
               nextLocalIdx += 1
               locals(sym) = idx
-              symsAtOffset(sym.span.start) += sym
+              symsAtOffset(startPos(sym)) += sym
               idx
         locals.getOrElseUpdate(sym, computeLocalIdx())
 

tests/pos-custom-args/semanticdb/inline-unapply/App_2.scala

@@ -0,0 +1,12 @@
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    0 match
+      case Succ(n) => ???
+      case _ =>
+
+    2 match
+      case Succ(n) => assert(n == 1)
+  }
+
+}

tests/pos-custom-args/semanticdb/inline-unapply/Macro_1.scala

@@ -0,0 +1,8 @@
+import scala.quoted._
+
+object Succ:
+
+  inline def unapply(n: Int): Option[Int] = ${ impl('n) }
+
+  private def impl(n: Expr[Int])(using QuoteContext): Expr[Option[Int]] =
+    '{ if $n == 0 then None else Some($n - 1)}