Fix #8325: Add missing span

compiler/src/dotty/tools/dotc/transform/localopt/StringInterpolatorOpt.scala

@@ -101,7 +101,7 @@ class StringInterpolatorOpt extends MiniPhase {
           val elemi = elems.iterator
           var result: Tree = stri.next
           def concat(tree: Tree): Unit = {
-            result = result.select(defn.String_+).appliedTo(tree)
+            result = result.select(defn.String_+).appliedTo(tree).withSpan(tree.span)
           }
           while (elemi.hasNext) {
             concat(elemi.next)

tests/pos-macros/i8325/Macro_1.scala

@@ -0,0 +1,21 @@
+package a
+
+import scala.quoted._
+import scala.quoted.matching._
+
+object A:
+
+  inline def transform[A](inline expr: A): A = ${
+    transformImplExpr('expr)
+  }
+
+  def pure[A](a:A):A = ???
+
+  def transformImplExpr[A:Type](using qctx: QuoteContext)(expr: Expr[A]): Expr[A] = {
+     import qctx.tasty.{given _, _}
+     expr.unseal match {
+         case Inlined(x,y,z) => transformImplExpr(z.seal.asInstanceOf[Expr[A]])
+         case Apply(fun,args) =>  '{  A.pure(${Apply(fun,args).seal.asInstanceOf[Expr[A]]}) }
+         case other => expr
+     }
+  }

tests/pos-macros/i8325/Test_2.scala

@@ -0,0 +1,10 @@
+package a
+
+class Test1 {
+
+   def t1(): Unit = {
+     A.transform(
+       s"a ${1} ${2}")
+  }
+
+}

tests/pos-macros/i8325b/Macro_1.scala

@@ -0,0 +1,22 @@
+package a
+
+import scala.quoted._
+import scala.quoted.matching._
+
+object A:
+
+  inline def transform[A](inline expr: A): A = ${
+    transformImplExpr('expr)
+  }
+
+  def pure[A](a:A):A = ???
+
+  def transformImplExpr[A:Type](using qctx: QuoteContext)(expr: Expr[A]): Expr[A] = {
+     import qctx.tasty.{given _, _}
+     expr.unseal match {
+         case Inlined(x,y,z) => transformImplExpr(z.seal.asInstanceOf[Expr[A]])
+         case r@Apply(fun,args) =>  '{
+              A.pure(${r.seal.asInstanceOf[Expr[A]]}) }
+         case other => expr
+     }
+  }

tests/pos-macros/i8325b/Test_2.scala

@@ -0,0 +1,10 @@
+package a
+
+class Test1 {
+
+   def t1(): Unit = {
+     A.transform(
+       s"a ${1} ${2}")
+  }
+
+}