diff options
Diffstat (limited to 'compiler/src/dotty')
4 files changed, 31 insertions, 5 deletions
diff --git a/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala b/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala index 1fffe6841..7f44af486 100644 --- a/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala +++ b/compiler/src/dotty/tools/dotc/sbt/ExtractAPI.scala @@ -6,6 +6,7 @@ import core._, core.Decorators._ import Annotations._, Contexts._, Flags._, Phases._, Trees._, Types._, Symbols._ import Names._, NameOps._, StdNames._ import typer.Inliner +import typer.ErrorReporting.cyclicErrorMsg import dotty.tools.io.Path import java.io.PrintWriter @@ -190,7 +191,16 @@ private class ExtractAPICollector(implicit val ctx: Context) extends ThunkHolder def apiClassStructure(csym: ClassSymbol): api.Structure = { val cinfo = csym.classInfo - val bases = linearizedAncestorTypes(cinfo) + val bases = + try linearizedAncestorTypes(cinfo) + catch { + case ex: CyclicReference => + // See neg/i1750a for an example where a cyclic error can arise. + // The root cause in this example is an illegal "override" of an inner trait + ctx.error(cyclicErrorMsg(ex), csym.pos) + defn.ObjectType :: Nil + } + val apiBases = bases.map(apiType) // Synthetic methods that are always present do not affect the API diff --git a/compiler/src/dotty/tools/dotc/transform/OverridingPairs.scala b/compiler/src/dotty/tools/dotc/transform/OverridingPairs.scala index 650a03054..1f1f371a6 100644 --- a/compiler/src/dotty/tools/dotc/transform/OverridingPairs.scala +++ b/compiler/src/dotty/tools/dotc/transform/OverridingPairs.scala @@ -6,6 +6,7 @@ import Flags._, Symbols._, Contexts._, Types._, Scopes._, Decorators._ import util.HashSet import collection.mutable import collection.immutable.BitSet +import typer.ErrorReporting.cyclicErrorMsg import scala.annotation.tailrec /** A module that can produce a kind of iterator (`Cursor`), @@ -122,10 +123,18 @@ object OverridingPairs { if (nextEntry ne null) { nextEntry = decls.lookupNextEntry(nextEntry) if (nextEntry ne null) { - overridden = nextEntry.sym - if (overriding.owner != overridden.owner && matches(overriding, overridden)) { - visited += overridden - if (!hasCommonParentAsSubclass(overriding.owner, overridden.owner)) return + try { + overridden = nextEntry.sym + if (overriding.owner != overridden.owner && matches(overriding, overridden)) { + visited += overridden + if (!hasCommonParentAsSubclass(overriding.owner, overridden.owner)) return + } + } + catch { + case ex: CyclicReference => + // See neg/i1750a for an example where a cyclic error can arise. + // The root cause in this example is an illegal "override" of an inner trait + ctx.error(cyclicErrorMsg(ex), base.pos) } } else { curEntry = curEntry.prev diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala index 41d9f9572..321c275d7 100644 --- a/compiler/src/dotty/tools/dotc/typer/Checking.scala +++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala @@ -338,6 +338,11 @@ object Checking { checkNoConflict(Final, Sealed) checkNoConflict(Private, Protected) checkNoConflict(Abstract, Override) + if (sym.isType && !sym.is(Deferred)) + for (cls <- sym.allOverriddenSymbols.filter(_.isClass)) { + fail(i"$sym cannot have the same name as ${cls.showLocated} -- class definitions cannot be overridden") + sym.setFlag(Private) // break the overriding relationship by making sym Private + } } /** Check the type signature of the symbol `M` defined by `tree` does not refer diff --git a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala index 3192546cd..e113399c5 100644 --- a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala +++ b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala @@ -289,6 +289,8 @@ object RefChecks { if (!isOverrideAccessOK) { overrideAccessError() } else if (other.isClass) { + // direct overrides were already checked on completion (see Checking.chckWellFormed) + // the test here catches indirect overriddes between two inherited base types. overrideError("cannot be used here - class definitions cannot be overridden") } else if (!other.is(Deferred) && member.isClass) { overrideError("cannot be used here - classes can only override abstract types") |