Fix staging using inline methods in quotes

Follow-up of scala#10709

compiler/src/dotty/tools/dotc/transform/Inlining.scala

@@ -0,0 +1,71 @@
+package dotty.tools.dotc
+package transform
+
+import core._
+import Decorators._
+import Flags._
+import Types._
+import Contexts._
+import Symbols._
+import Constants._
+import ast.Trees._
+import ast.{TreeTypeMap, untpd}
+import util.Spans._
+import tasty.TreePickler.Hole
+import SymUtils._
+import NameKinds._
+import dotty.tools.dotc.ast.tpd
+import typer.Implicits.SearchFailureType
+
+import scala.collection.mutable
+import dotty.tools.dotc.core.Annotations._
+import dotty.tools.dotc.core.Names._
+import dotty.tools.dotc.core.StdNames._
+import dotty.tools.dotc.core.StagingContext._
+import dotty.tools.dotc.quoted._
+import dotty.tools.dotc.transform.TreeMapWithStages._
+import dotty.tools.dotc.typer.Inliner
+import dotty.tools.dotc.typer.ImportInfo.withRootImports
+
+import scala.annotation.constructorOnly
+
+/** Inlines all calls to inline methods that are not in an inline method or a quote */
+class Inlining extends MacroTransform {
+  import tpd._
+
+  override def phaseName: String = Inlining.name
+
+  override def allowsImplicitSearch: Boolean = true
+
+  override def checkPostCondition(tree: Tree)(using Context): Unit =
+    tree match {
+      case tree: RefTree if !Inliner.inInlineMethod && StagingContext.level == 0 =>
+        assert(!tree.symbol.isInlineMethod)
+      case _ =>
+    }
+
+  protected def newTransformer(using Context): Transformer = new Transformer {
+    override def transform(tree: tpd.Tree)(using Context): tpd.Tree =
+      tree match
+        case tree: DefTree =>
+          if tree.symbol.is(Inline) then tree
+          else super.transform(tree)
+        case _: Typed | _: Block =>
+          super.transform(tree)
+        case _ if Inliner.isInlineable(tree) && !tree.tpe.widen.isInstanceOf[MethodOrPoly] && StagingContext.level == 0 =>
+          val tree1 = super.transform(tree)
+          val inlined = Inliner.inlineCall(tree1)
+          if tree1 eq inlined then inlined
+          else transform(inlined)
+        case _: TypeApply if tree.symbol.isQuote =>
+          ctx.compilationUnit.needsStaging = true
+          super.transform(tree)
+        case _ =>
+          super.transform(tree)
+
+  }
+}
+
+object Inlining {
+  val name: String = "inlining"
+}

staging/src/scala/quoted/staging/QuoteCompiler.scala

@@ -16,7 +16,7 @@ import dotty.tools.dotc.core.Symbols._
 import dotty.tools.dotc.core.Types.ExprType
 import dotty.tools.dotc.quoted.PickledQuotes
 import dotty.tools.dotc.transform.Splicer.checkEscapedVariables
-import dotty.tools.dotc.transform.PickleQuotes
+import dotty.tools.dotc.transform.{Inlining, PickleQuotes}
 import dotty.tools.dotc.util.Spans.Span
 import dotty.tools.dotc.util.SourceFile
 import dotty.tools.io.{Path, VirtualFile}
@@ -39,7 +39,9 @@ private class QuoteCompiler extends Compiler:
     List(List(new QuotedFrontend))
 
   override protected def picklerPhases: List[List[Phase]] =
-    List(List(new PickleQuotes))
+    List(new Inlining) ::
+    List(new PickleQuotes) ::
+    Nil
 
   override def newRun(implicit ctx: Context): ExprRun =
     reset()

tests/run-staging/i3876-d.check

@@ -1,2 +1,2 @@
 6
-6
+Test.inlineLambda.apply(3)

tests/run-staging/quote-toExprOfTuple.check

@@ -21,3 +21,6 @@
 (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
 (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21)
 (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25)

tests/run-staging/quote-toExprOfTuple.scala

@@ -5,7 +5,7 @@ import scala.quoted.staging._
 object Test {
   given Toolbox = Toolbox.make(getClass.getClassLoader)
   def main(args: Array[String]): Unit = {
-    for (n <- 0 to 22) { // FIXME should go up to 25. This should be fixed in #9984
+    for (n <- 0 to 25) {
       prev = 0
       println(run { Expr.ofTupleFromSeq(Seq.fill(n)('{next})) })
     }