A simpler implementation of init checker

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

@@ -26,6 +26,8 @@ class Checker extends MiniPhase {
   // cache of class summary
   private val cache = new Cache
 
+  private val semantic = new Semantic
+
   override val runsAfter = Set(Pickler.name)
 
   override def isEnabled(using Context): Boolean =
@@ -57,7 +59,14 @@ class Checker extends MiniPhase {
         env = Env(ctx.withOwner(cls), cache)
       )
 
-      Checking.checkClassBody(tree)
+      // Checking.checkClassBody(tree)
+
+      import semantic._
+      val tpl = tree.rhs.asInstanceOf[Template]
+      val thisRef = ThisRef(cls)
+      val heap = Objekt(cls, fields = mutable.Map.empty)
+      val res = eval(tpl, thisRef, cls)(using heap, ctx, Vector.empty)
+      res.errors.foreach(_.issue)
     }
 
     tree

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

@@ -321,7 +321,6 @@ object Checking {
       val f = denot.symbol
       if !f.isOneOf(excludedFlags) && f.hasSource then
         buffer += Promote(FieldReturn(warm, f)(source))(source)
-        buffer += FieldAccess(warm, f)(source)
     }
 
     classRef.membersBasedOnFlags(Flags.Method, Flags.Deferred).foreach { denot =>
@@ -342,7 +341,7 @@ object Checking {
     for (eff <- buffer.toList) {
       val errs = check(eff)
       if !errs.isEmpty then
-        return UnsafePromotion(warm, eff.source, state.path, errs.toList).toErrors
+        return UnsafePromotion(eff.source, state.path, errs.toList).toErrors
     }
     Errors.empty
 
@@ -355,7 +354,7 @@ object Checking {
           Errors.empty
         else pot match {
           case pot: ThisRef =>
-              PromoteThis(pot, eff.source, state.path).toErrors
+              PromoteThis(eff.source, state.path).toErrors
 
           case _: Cold =>
             PromoteCold(eff.source, state.path).toErrors
@@ -374,7 +373,7 @@ object Checking {
             }
 
             if (errs1.nonEmpty || errs2.nonEmpty)
-              UnsafePromotion(pot, eff.source, state.path, errs1 ++ errs2).toErrors
+              UnsafePromotion(eff.source, state.path, errs1 ++ errs2).toErrors
             else
               Errors.empty
 

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

@@ -12,7 +12,7 @@ import Types._, Symbols._, Contexts._
 import Effects._, Potentials._
 
 object Errors {
-  type Errors = List[Error]
+  type Errors = Seq[Error]
   val empty: Errors = Nil
 
   def show(errs: Errors)(using Context): String =
@@ -70,12 +70,12 @@ object Errors {
   }
 
   /** Promote `this` under initialization to fully-initialized */
-  case class PromoteThis(pot: ThisRef, source: Tree, trace: Vector[Tree]) extends Error {
+  case class PromoteThis(source: Tree, trace: Vector[Tree]) extends Error {
     def show(using Context): String = "Promote the value under initialization to fully-initialized."
   }
 
   /** Promote `this` under initialization to fully-initialized */
-  case class PromoteWarm(pot: Warm, source: Tree, trace: Vector[Tree]) extends Error {
+  case class PromoteWarm(source: Tree, trace: Vector[Tree]) extends Error {
     def show(using Context): String =
       "Promoting the value under initialization to fully-initialized."
   }
@@ -98,11 +98,12 @@ object Errors {
 
   case class CallUnknown(meth: Symbol, source: Tree, trace: Vector[Tree]) extends Error {
     def show(using Context): String =
-      "Calling the external method " + meth.show + " may cause initialization errors" + "."
+      val prefix = if meth.is(Flags.Method) then "Calling the external method " else "Accessing the external field"
+      prefix + meth.show + " may cause initialization errors" + "."
   }
 
   /** Promote a value under initialization to fully-initialized */
-  case class UnsafePromotion(pot: Potential, source: Tree, trace: Vector[Tree], errors: Errors) extends Error {
+  case class UnsafePromotion(source: Tree, trace: Vector[Tree], errors: Errors) extends Error {
     assert(errors.nonEmpty)
 
     override def issue(using Context): Unit =