Fix #12128: Add test

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

@@ -11,15 +11,14 @@ import ast.untpd
 /** Operations that are shared between Namer and TreeUnpickler */
 object NamerOps:
 
-  /** The given type, unless `sym` is a constructor, in which case the
-   *  type of the constructed instance is returned
+  /** The type of the constructed instance is returned
+   *
+   *  @param ctor the constructor
    */
-  def effectiveResultType(sym: Symbol, paramss: List[List[Symbol]], givenTp: Type)(using Context): Type =
-    if sym.name == nme.CONSTRUCTOR then
-      paramss match
-        case TypeSymbols(tparams) :: _ => sym.owner.typeRef.appliedTo(tparams.map(_.typeRef))
-        case _ => sym.owner.typeRef
-    else givenTp
+  def effectiveResultType(ctor: Symbol, paramss: List[List[Symbol]])(using Context): Type =
+    paramss match
+      case TypeSymbols(tparams) :: _ => ctor.owner.typeRef.appliedTo(tparams.map(_.typeRef))
+      case _ => ctor.owner.typeRef
 
   /** if isConstructor, make sure it has one leading non-implicit parameter list */
   def normalizeIfConstructor(paramss: List[List[Symbol]], isConstructor: Boolean)(using Context): List[List[Symbol]] =

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

@@ -332,6 +332,7 @@ class TreePickler(pickler: TastyPickler) {
 
   def pickleDef(tag: Int, mdef: MemberDef, tpt: Tree, rhs: Tree = EmptyTree, pickleParams: => Unit = ())(using Context): Unit = {
     val sym = mdef.symbol
+
     assert(symRefs(sym) == NoAddr, sym)
     registerDef(sym)
     writeByte(tag)

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

@@ -831,7 +831,11 @@ class TreeUnpickler(reader: TastyReader,
           val tpt = readTpt()(using localCtx)
           val paramss = normalizeIfConstructor(
               paramDefss.nestedMap(_.symbol), name == nme.CONSTRUCTOR)
-          val resType = effectiveResultType(sym, paramss, tpt.tpe)
+          val resType =
+            if name == nme.CONSTRUCTOR then
+              effectiveResultType(sym, paramss)
+            else
+              tpt.tpe
           sym.info = methodType(paramss, resType)
           DefDef(paramDefss, tpt)
         case VALDEF =>

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

@@ -91,7 +91,7 @@ class TreeChecker extends Phase with SymTransformer {
     // until erasure, see the comment above `Compiler#phases`.
     if (ctx.phaseId <= erasurePhase.id) {
       val initial = symd.initial
-      assert(symd.signature == initial.signature,
+      assert(symd == initial || symd.signature == initial.signature,
         i"""Signature of ${sym.showLocated} changed at phase ${ctx.base.fusedContaining(ctx.phase.prev)}
            |Initial info: ${initial.info}
            |Initial sig : ${initial.signature}

compiler/src/dotty/tools/dotc/transform/init/Semantic.scala

@@ -830,6 +830,7 @@ class Semantic {
 
       // follow constructor
       if cls.hasSource then
+        printer.println("init super class " + cls.show)
         val res2 = thisV.call(ctor, superType = NoType, source)(using ctx, trace.add(source))
         errorBuffer ++= res2.errors
 

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

@@ -1680,7 +1680,7 @@ class Namer { typer: Typer =>
     if (isConstructor) {
       // set result type tree to unit, but take the current class as result type of the symbol
       typedAheadType(ddef.tpt, defn.UnitType)
-      wrapMethType(effectiveResultType(sym, paramSymss, NoType))
+      wrapMethType(effectiveResultType(sym, paramSymss))
     }
     else valOrDefDefSig(ddef, sym, paramSymss, wrapMethType)
   }

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -325,6 +325,27 @@ class CompilationTests {
     compileFilesInDir("tests/init/neg", options).checkExpectedErrors()
     compileFilesInDir("tests/init/pos", options).checkCompile()
     compileFilesInDir("tests/init/crash", options.without("-Xfatal-warnings")).checkCompile()
+
+    // The regression test for i12128 has some atypical classpath requirements.
+    // The test consists of three files: (a) Reflect_1  (b) Macro_2  (c) Test_3
+    // which must be compiled separately. In addition:
+    //   - the output from (a) must be on the classpath while compiling (b)
+    //   - the output from (b) must be on the classpath while compiling (c)
+    //   - the output from (a) _must not_ be on the classpath while compiling (c)
+    locally {
+      val i12128Group = TestGroup("checkInit/i12128")
+      val i12128Options = options.without("-Xfatal-warnings")
+      val outDir1 = defaultOutputDir + i12128Group + "/Reflect_1/i12128/Reflect_1"
+      val outDir2 = defaultOutputDir + i12128Group + "/Macro_2/i12128/Macro_2"
+
+      val tests = List(
+        compileFile("tests/init/special/i12128/Reflect_1.scala", i12128Options)(i12128Group),
+        compileFile("tests/init/special/i12128/Macro_2.scala", i12128Options.withClasspath(outDir1))(i12128Group),
+        compileFile("tests/init/special/i12128/Test_3.scala", options.withClasspath(outDir2))(i12128Group)
+      ).map(_.keepOutput.checkCompile())
+
+      tests.foreach(_.delete())
+    }
   }
 }
 

tests/init/special/i12128/Macro_2.scala

@@ -0,0 +1,21 @@
+import scala.quoted._
+import scala.language.experimental.macros
+
+class Location(val line: Int)
+
+object MacroCompat {
+  trait LocationMacro {
+    inline implicit def generate: Location = ${ locationImpl() }
+    implicit def generate: Location = macro MacroCompatScala2.locationImpl
+  }
+
+  def locationImpl()(using Quotes): Expr[Location] = '{ new Location(${Expr(0)}) }
+}
+
+object MacroCompatScala2 {
+  def locationImpl(c: Context): c.Tree = {
+    import c.universe._
+    val line = Literal(Constant(c.enclosingPosition.line))
+    New(c.mirror.staticClass(classOf[Location].getName()), line)
+  }
+}

tests/init/special/i12128/Reflect_1.scala

@@ -0,0 +1,30 @@
+trait Context: // Dummy scala.reflect.macros.Context
+  type Tree = universe.Tree
+  val universe: Universe
+
+  trait Universe {
+    type Tree >: Null <: AnyRef with TreeApi
+    type Literal >: Null <: LiteralApi with TermTree
+    type TermTree >: Null <: TermTreeApi with Tree
+
+    trait TermTreeApi extends TreeApi { this: TermTree => }
+    trait LiteralApi extends TermTreeApi { this: Literal => }
+    trait TreeApi extends Product { this: Tree => }
+
+    type Constant
+
+    type Type
+
+    def Literal(const: Constant): Tree
+    def Constant(i: Int): Constant
+    def New(tpe: Type, arg: Tree): Tree
+  }
+
+  def enclosingPosition: Position
+
+  trait Mirror {
+    def staticClass(name: String): universe.Type
+  }
+  val mirror: Mirror
+
+class Position(val line: Int)

tests/init/special/i12128/Test_3.scala

@@ -0,0 +1 @@
+object Test extends MacroCompat.LocationMacro