Move blackbox macro expansion to ReifyQuotes

compiler/src/dotty/tools/dotc/core/Flags.scala

@@ -350,6 +350,9 @@ object Flags {
   /** An opaque type alias or a class containing one */
   val (Opaque @ _, _, _) = newFlags(43, "opaque")
 
+  /** An transparent inline method */
+  val (_, Transparent @ _, _) = newFlags(44, "transparent")
+
 
   // ------------ Flags following this one are not pickled ----------------------------------
 
@@ -426,7 +429,7 @@ object Flags {
     CommonSourceModifierFlags.toTypeFlags | Abstract | Sealed | Opaque | Open
 
   val TermSourceModifierFlags: FlagSet =
-    CommonSourceModifierFlags.toTermFlags | Inline | AbsOverride | Lazy | Erased
+    CommonSourceModifierFlags.toTermFlags | Inline | AbsOverride | Lazy | Erased | Transparent
 
   /** Flags representing modifiers that can appear in trees */
   val ModifierFlags: FlagSet =
@@ -443,7 +446,7 @@ object Flags {
     Scala2SpecialFlags, MutableOrOpen, Opaque, Touched, JavaStatic,
     OuterOrCovariant, LabelOrContravariant, CaseAccessor,
     Extension, NonMember, Implicit, Given, Permanent, Synthetic,
-    SuperParamAliasOrScala2x, Inline, Macro)
+    SuperParamAliasOrScala2x, Inline, Macro, Transparent)
 
   /** Flags that are not (re)set when completing the denotation, or, if symbol is
    *  a top-level class or object, when completing the denotation once the class

compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala

@@ -699,6 +699,7 @@ class TreePickler(pickler: TastyPickler) {
       if (flags.is(ParamAccessor)) writeModTag(PARAMsetter)
       if (flags.is(SuperParamAlias)) writeModTag(PARAMalias)
       if (flags.is(Exported)) writeModTag(EXPORTED)
+      if (flags.is(Transparent)) writeModTag(TRANSPARENT)
       assert(!(flags.is(Label)))
     }
     else {

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -635,6 +635,7 @@ class TreeUnpickler(reader: TastyReader,
           case INLINE => addFlag(Inline)
           case INLINEPROXY => addFlag(InlineProxy)
           case MACRO => addFlag(Macro)
+          case TRANSPARENT => addFlag(Transparent)
           case OPAQUE => addFlag(Opaque)
           case STATIC => addFlag(JavaStatic)
           case OBJECT => addFlag(Module)

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

@@ -195,8 +195,7 @@ class ReifyQuotes extends MacroTransform {
           case splice: Select => cpy.Select(splice)(body1, splice.name)
         }
       }
-      else {
-        assert(level == 1, "unexpected top splice outside quote")
+      else if (level == 1) {
         val (body1, quotes) = nested(isQuote = false).splitSplice(body)(spliceContext)
         val tpe = outer.embedded.getHoleType(body, splice)
         val hole = makeHole(splice.isTerm, body1, quotes, tpe).withSpan(splice.span)
@@ -206,6 +205,10 @@ class ReifyQuotes extends MacroTransform {
         // For example we can have a lifted tree containing the LHS of an assignment (see tests/run-with-compiler/quote-var.scala).
         if (splice.isType || outer.embedded.isLiftedSymbol(body.symbol)) hole
         else Inlined(EmptyTree, Nil, hole).withSpan(splice.span)
+      } else {
+        assert(level == 0, "unexpected splice insiced top splice")
+        val newBody = Inliner.expandMacro(body, splice.span)
+        transform(newBody)
       }
 
     /** Transforms the contents of a nested splice

compiler/src/dotty/tools/dotc/typer/Inliner.scala

@@ -325,6 +325,27 @@ object Inliner {
       val errors = compileForErrors(tree, false)
       packErrors(errors)
   }
+
+  def expandMacro(body: Tree, span: Span)(implicit ctx: Context) = {
+    assert(level == 0)
+    val inlinedFrom = enclosingInlineds.last
+    val ctx1 = tastyreflect.MacroExpansion.context(inlinedFrom)
+
+    val evaluatedSplice = inContext(tastyreflect.MacroExpansion.context(inlinedFrom)) {
+      Splicer.splice(body, inlinedFrom.sourcePos, MacroClassLoader.fromContext)
+    }
+
+    val inlinedNormailizer = new TreeMap {
+      override def transform(tree: tpd.Tree)(implicit ctx: Context): tpd.Tree = tree match {
+        case Inlined(EmptyTree, Nil, expr) if enclosingInlineds.isEmpty => transform(expr)
+        case _ => super.transform(tree)
+      }
+    }
+    val normalizedSplice = inlinedNormailizer.transform(evaluatedSplice)
+    if (normalizedSplice.isEmpty) normalizedSplice
+    else normalizedSplice.withSpan(span)
+  }
+
 }
 
 /** Produces an inlined version of `call` via its `inlined` method.
@@ -1233,7 +1254,14 @@ class Inliner(call: tpd.Tree, rhsToInline: tpd.Tree)(using Context) {
         case res: Apply if res.symbol == defn.InternalQuoted_exprSplice
                         && level == 0
                         && !suppressInline =>
-          expandMacro(res.args.head, tree.span)
+          val body = res.args.head
+          checkMacroDependencies(body, call.sourcePos)
+          if call.symbol.is(Transparent) then
+            expandMacro(res.args.head, tree.span)
+          else
+            // Blackbox macros expanded later in ReifyQuotes
+            ctx.compilationUnit.needsStaging = true
+            res
         case res => res
       }
 
@@ -1391,31 +1419,16 @@ class Inliner(call: tpd.Tree, rhsToInline: tpd.Tree)(using Context) {
     }
   }
 
-  private def expandMacro(body: Tree, span: Span)(using Context) = {
+  private def checkMacroDependencies(body: Tree, callPos: SourcePosition)(implicit ctx: Context): Unit = {
     assert(level == 0)
-    val inlinedFrom = enclosingInlineds.last
     val dependencies = macroDependencies(body)
-
     if dependencies.nonEmpty && !ctx.reporter.errorsReported then
       for sym <- dependencies do
         if ctx.compilationUnit.source.file == sym.associatedFile then
-          ctx.error(em"Cannot call macro $sym defined in the same source file", call.sourcePos)
+          ctx.error(em"Cannot call macro $sym defined in the same source file", callPos)
         if (ctx.settings.XprintSuspension.value)
-          ctx.echo(i"suspension triggered by macro call to ${sym.showLocated} in ${sym.associatedFile}", call.sourcePos)
+          ctx.echo(i"suspension triggered by macro call to ${sym.showLocated} in ${sym.associatedFile}", callPos)
       ctx.compilationUnit.suspend() // this throws a SuspendException
-
-    val evaluatedSplice = inContext(tastyreflect.MacroExpansion.context(inlinedFrom)) {
-      Splicer.splice(body, inlinedFrom.sourcePos, MacroClassLoader.fromContext)
-    }
-    val inlinedNormailizer = new TreeMap {
-      override def transform(tree: tpd.Tree)(using Context): tpd.Tree = tree match {
-        case Inlined(EmptyTree, Nil, expr) if enclosingInlineds.isEmpty => transform(expr)
-        case _ => super.transform(tree)
-      }
-    }
-    val normalizedSplice = inlinedNormailizer.transform(evaluatedSplice)
-    if (normalizedSplice.isEmpty) normalizedSplice
-    else normalizedSplice.withSpan(span)
   }
 
   /** Return the set of symbols that are referred at level -1 by the tree and defined in the current run.

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1917,6 +1917,9 @@ class Typer extends Namer
 
     if (sym.isInlineMethod)
       val rhsToInline = PrepareInlineable.wrapRHS(ddef, tpt1, rhs1)
+      rhsToInline match
+        case _: Typed =>
+        case _ => sym.setFlag(Transparent) // FIXME Tag whitebox macros (do it in desugar)
       PrepareInlineable.registerInlineInfo(sym, rhsToInline)
 
     if (sym.isConstructor && !sym.isPrimaryConstructor) {

tasty/src/dotty/tools/tasty/TastyFormat.scala

@@ -185,6 +185,7 @@ Standard-Section: "ASTs" TopLevelStat*
                   OPAQUE                                                           -- opaque, also used for classes containing opaque aliases
                   INLINE                                                           -- inline
                   MACRO                                                            -- Inline method containing toplevel splices
+                  TRANSPARENT                                                      -- Transparent inline method
                   INLINEPROXY                                                      -- Symbol of binding with an argument to an inline method as rhs (TODO: do we still need this?)
                   STATIC                                                           -- Mapped to static Java member
                   OBJECT                                                           -- An object or its class
@@ -254,7 +255,7 @@ Standard Section: "Comments" Comment*
 object TastyFormat {
 
   final val header: Array[Int] = Array(0x5C, 0xA1, 0xAB, 0x1F)
-  val MajorVersion: Int = 23
+  val MajorVersion: Int = 24
   val MinorVersion: Int = 0
 
   /** Tags used to serialize names, should update [[nameTagToString]] if a new constant is added */
@@ -351,16 +352,17 @@ object TastyFormat {
   final val HASDEFAULT = 31
   final val STABLE = 32
   final val MACRO = 33
-  final val ERASED = 34
-  final val OPAQUE = 35
-  final val EXTENSION = 36
-  final val GIVEN = 37
-  final val PARAMsetter = 38
-  final val EXPORTED = 39
-  final val OPEN = 40
-  final val PARAMEND = 41
-  final val PARAMalias = 42
-  final val SUPERTRAIT = 43
+  final val TRANSPARENT = 34
+  final val ERASED = 35
+  final val OPAQUE = 36
+  final val EXTENSION = 37
+  final val GIVEN = 38
+  final val PARAMsetter = 39
+  final val EXPORTED = 40
+  final val OPEN = 41
+  final val PARAMEND = 42
+  final val PARAMalias = 43
+  final val SUPERTRAIT = 44
 
   // Cat. 2:    tag Nat
 
@@ -500,6 +502,7 @@ object TastyFormat {
        | INLINE
        | INLINEPROXY
        | MACRO
+       | TRANSPARENT
        | OPAQUE
        | STATIC
        | OBJECT
@@ -561,6 +564,7 @@ object TastyFormat {
     case INLINE => "INLINE"
     case INLINEPROXY => "INLINEPROXY"
     case MACRO => "MACRO"
+    case TRANSPARENT => "TRANSPARENT"
     case OPAQUE => "OPAQUE"
     case STATIC => "STATIC"
     case OBJECT => "OBJECT"

tests/neg-macros/i6530.scala

@@ -1,4 +1,7 @@
 object Macros {
   inline def q : Int = ${ '[ Int ] } // error
   val x : Int = 1 + q // error
+
+  transparent inline def q2: Int = ${ '[ Int ] } // error
+  val y : Int = 1 + q2 // error
 }

tests/run-custom-args/Yretain-trees/tasty-definitions-3.check

@@ -1,3 +1,3 @@
-DefDef("foo", Nil, Nil, Inferred(), None)
-ValDef("bar", Inferred(), None)
+DefDef("foo", Nil, Nil, TypeIdent("Int"), Some(Apply(Select(Literal(Constant(1)), "+"), List(Literal(Constant(2))))))
+ValDef("bar", TypeIdent("Int"), Some(Apply(Select(Literal(Constant(2)), "+"), List(Literal(Constant(3))))))
 Bind("x", Ident("_"))

tests/run-custom-args/Yretain-trees/tasty-extractors-owners.check

@@ -1,5 +1,5 @@
 foo
-ValDef("macro", Inferred(), None)
+DefDef("main", Nil, List(List(ValDef("args", Applied(TypeIdent("Array"), List(TypeIdent("String"))), None))), TypeIdent("Unit"), Some(Block(Nil, Inlined(Some(Projection(Inferred(), "Macros$")), Nil, Typed(Apply(TypeApply(Ident("exprSplice"), List(Inferred())), List(Block(List(DefDef("$anonfun", Nil, List(List(ValDef("evidence$1", Inferred(), None))), Inferred(), Some(Apply(Apply(TypeApply(Ident("impl"), List(Inferred())), List(Apply(Select(Apply(TypeApply(Ident("exprQuote"), List(Inferred())), List(Inlined(None, Nil, Block(List(DefDef("foo", Nil, Nil, Inferred(), Some(Block(List(DefDef("bar", Nil, Nil, Inferred(), Some(Literal(Constant(1)))), ValDef("bar2", Inferred(), Some(Literal(Constant(2))))), Typed(Ident("bar"), Inferred())))), ValDef("foo2", Inferred(), Some(Block(List(DefDef("baz", Nil, Nil, Inferred(), Some(Literal(Constant(3)))), ValDef("baz2", Inferred(), Some(Literal(Constant(4))))), Typed(Ident("baz"), Inferred())))), ClassDef("A", DefDef("<init>", Nil, List(Nil), Inferred(), None), List(Apply(Select(New(Inferred()), "<init>"), Nil)), Nil, None, List(TypeDef("B", TypeIdent("Int")), DefDef("b", Nil, Nil, Inferred(), Some(Literal(Constant(5)))), ValDef("b2", Inferred(), Some(Literal(Constant(6))))))), Literal(Constant(())))))), "apply"), List(Ident("evidence$1"))))), List(Ident("evidence$1")))))), Closure(Ident("$anonfun"), None)))), TypeIdent("Unit"))))))
 
 bar
 DefDef("foo", Nil, Nil, Inferred(), None)
@@ -8,7 +8,7 @@ bar2
 DefDef("foo", Nil, Nil, Inferred(), None)
 
 foo2
-ValDef("macro", Inferred(), None)
+DefDef("main", Nil, List(List(ValDef("args", Applied(TypeIdent("Array"), List(TypeIdent("String"))), None))), TypeIdent("Unit"), Some(Block(Nil, Inlined(Some(Projection(Inferred(), "Macros$")), Nil, Typed(Apply(TypeApply(Ident("exprSplice"), List(Inferred())), List(Block(List(DefDef("$anonfun", Nil, List(List(ValDef("evidence$1", Inferred(), None))), Inferred(), Some(Apply(Apply(TypeApply(Ident("impl"), List(Inferred())), List(Apply(Select(Apply(TypeApply(Ident("exprQuote"), List(Inferred())), List(Inlined(None, Nil, Block(List(DefDef("foo", Nil, Nil, Inferred(), Some(Block(List(DefDef("bar", Nil, Nil, Inferred(), Some(Literal(Constant(1)))), ValDef("bar2", Inferred(), Some(Literal(Constant(2))))), Typed(Ident("bar"), Inferred())))), ValDef("foo2", Inferred(), Some(Block(List(DefDef("baz", Nil, Nil, Inferred(), Some(Literal(Constant(3)))), ValDef("baz2", Inferred(), Some(Literal(Constant(4))))), Typed(Ident("baz"), Inferred())))), ClassDef("A", DefDef("<init>", Nil, List(Nil), Inferred(), None), List(Apply(Select(New(Inferred()), "<init>"), Nil)), Nil, None, List(TypeDef("B", TypeIdent("Int")), DefDef("b", Nil, Nil, Inferred(), Some(Literal(Constant(5)))), ValDef("b2", Inferred(), Some(Literal(Constant(6))))))), Literal(Constant(())))))), "apply"), List(Ident("evidence$1"))))), List(Ident("evidence$1")))))), Closure(Ident("$anonfun"), None)))), TypeIdent("Unit"))))))
 
 baz
 ValDef("foo2", Inferred(), None)

tests/run-custom-args/Yretain-trees/tasty-load-tree-2.check

@@ -1,2 +1,2 @@
-DefDef("foo", Nil, Nil, Inferred(), None)
-ValDef("bar", Inferred(), None)
+DefDef("foo", Nil, Nil, TypeIdent("Int"), Some(Apply(Select(Literal(Constant(1)), "+"), List(Literal(Constant(2))))))
+ValDef("bar", TypeIdent("Int"), Some(Apply(Select(Literal(Constant(2)), "+"), List(Literal(Constant(3))))))

tests/run-macros/box/Macro_1.scala

@@ -0,0 +1,11 @@
+import scala.quoted._
+
+object Macros {
+
+  inline def blackbox: Int = ${one}
+
+  transparent inline def whitebox: Int = ${one}
+
+  private def one(using QuoteContext): Expr[Int] = Expr(1)
+
+}

tests/run-macros/box/Test_2.scala

@@ -0,0 +1,12 @@
+import scala.quoted._
+import Macros._
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val a: Int = blackbox
+    val b: 1 = whitebox
+
+    assert(a == 1)
+    assert(b == 1)
+  }
+}

tests/run-macros/reflect-inline/assert_1.scala

@@ -1,13 +1,13 @@
 import scala.quoted._
 
 object api {
-  inline def (inline x: String) stripMargin: String =
+  transparent inline def (inline x: String) stripMargin: String =
     ${ stripImpl('x) }
 
   private def stripImpl(x: Expr[String])(using qctx: QuoteContext): Expr[String] =
     Expr(augmentString(x.unliftOrError).stripMargin)
 
-  inline def typeChecks(inline x: String): Boolean =
+  transparent inline def typeChecks(inline x: String): Boolean =
     ${ typeChecksImpl('{scala.compiletime.testing.typeChecks(x)}) }
 
   private def typeChecksImpl(b: Expr[Boolean])(using qctx: QuoteContext): Expr[Boolean] = {