Adjust assertions and errors to be more relaxed under --from-tasty compilation (Mode.ReadPositions)

Author: WojciechMazur

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -1012,12 +1012,12 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
       else cpy.PackageDef(tree)(pid, slicedStats) :: Nil
     case tdef: TypeDef =>
       val sym = tdef.symbol
-      assert(sym.isClass || ctx.tolerateErrorsForBestEffort)
+      assert(sym.isClass || ctx.tolerateErrorsForBestEffort || ctx.mode.is(Mode.ReadPositions))
       if (cls == sym || cls == sym.linkedClass) tdef :: Nil
       else Nil
     case vdef: ValDef =>
       val sym = vdef.symbol
-      assert(sym.is(Module) || ctx.tolerateErrorsForBestEffort)
+      assert(sym.is(Module) || ctx.tolerateErrorsForBestEffort || ctx.mode.is(Mode.ReadPositions))
       if (cls == sym.companionClass || cls == sym.moduleClass) vdef :: Nil
       else Nil
     case tree =>

compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala

@@ -113,7 +113,7 @@ object CheckCaptures:
         if refSym.isType && !refSym.info.derivesFrom(defn.Caps_CapSet) then
           report.error(em"$elem is not a legal element of a capture set", ann.srcPos)
       case ref: CoreCapability =>
-        if !ref.isTrackableRef && !ref.isCapRef then
+        if !ref.isTrackableRef && !ref.isCapRef && !ctx.mode.is(Mode.ReadPositions) then
           report.error(em"$elem cannot be tracked since it is not a parameter or local value", ann.srcPos)
       case ReachCapability(ref) =>
         check(ref)

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

@@ -2053,7 +2053,7 @@ object SymDenotations {
         case p :: parents1 =>
           p.classSymbol match {
             case pcls: ClassSymbol => builder.addAll(pcls.baseClasses)
-            case _ => assert(isRefinementClass || p.isError || ctx.mode.is(Mode.Interactive) || ctx.tolerateErrorsForBestEffort, s"$this has non-class parent: $p")
+            case _ => assert(isRefinementClass || p.isError || ctx.mode.is(Mode.Interactive) || ctx.tolerateErrorsForBestEffort || ctx.mode.is(Mode.ReadPositions), s"$this has non-class parent: $p")
           }
           traverse(parents1)
         case nil =>

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

@@ -1687,7 +1687,7 @@ trait Checking {
       val tname = sym.targetName
       if tname != sym.name then
         val preExisting = ctx.effectiveScope.lookup(tname)
-        if preExisting.exists || seen.contains(tname) then
+        if (preExisting.exists || seen.contains(tname)) && !ctx.mode.is(Mode.ReadPositions) then
           report.error(em"@targetName annotation ${'"'}$tname${'"'} clashes with other definition in same scope", stat.srcPos)
         if stat.isDef then seen += tname
 

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

@@ -1098,7 +1098,7 @@ trait Implicits:
   def inferImplicit(pt: Type, argument: Tree, span: Span, ignored: Set[Symbol] = Set.empty)(using Context): SearchResult = ctx.profiler.onImplicitSearch(pt):
     trace(s"search implicit ${pt.show}, arg = ${argument.show}: ${argument.tpe.show}", implicits, show = true) {
       record("inferImplicit")
-      assert(ctx.phase.allowsImplicitSearch,
+      assert(ctx.phase.allowsImplicitSearch || ctx.mode.is(Mode.ReadPositions),
         if (argument.isEmpty) i"missing implicit parameter of type $pt after typer at phase ${ctx.phase}"
         else i"type error: ${argument.tpe} does not conform to $pt${err.whyNoMatchStr(argument.tpe, pt)}")
 

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

@@ -3287,7 +3287,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
           selfType.member(decl.name).symbol.filter(other => other.isClass && other.owner != cls)
         decls.iterator.filter(_.isType).foldLeft(false) { (foundRedef, decl) =>
           val other = memberInSelfButNotThis(decl)
-          if (other.exists) {
+          if (other.exists && !ctx.mode.is(Mode.ReadPositions)) {
             val msg = CannotHaveSameNameAs(decl, other, CannotHaveSameNameAs.DefinedInSelf(self))
             report.error(msg, decl.srcPos)
           }