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SI-5361 Avoid cyclic type with malformed refinement

The statement `val x = this` in the refinment type:

    (new {}): {val x = this}

is lazily typechecked, in order to, according to the comment
in `typedRefinment, "avoid cyclic reference errors".

But the approximate type used ends up with:

    Refinment@1(
      parents = [...]
      decls = { val x: Refinement@1 })

This commit eagerly checks that there is no term definitions
in type refinments, rather than delaying this.

This changes the error message for SI-3614.
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1 parent fd57069 commit 327083df40d1854f28c00983aed5734fa6a7e6f9 @retronym retronym committed Dec 4, 2012
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8 src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2710,6 +2710,12 @@ trait Typers extends Modes with Adaptations with Tags {
def typedRefinement(templ: Template) {
val stats = templ.body
namer.enterSyms(stats)
+
+ // This is also checked later in typedStats, but that is too late for SI-5361, so
+ // we eagerly check this here.
+ for (stat <- stats if !treeInfo.isDeclarationOrTypeDef(stat))
+ OnlyDeclarationsError(stat)
+
// need to delay rest of typedRefinement to avoid cyclic reference errors
unit.toCheck += { () =>
val stats1 = typedStats(stats, NoSymbol)
@@ -5068,7 +5074,7 @@ trait Typers extends Modes with Adaptations with Tags {
val self = refinedType(parents1 map (_.tpe), context.enclClass.owner, decls, templ.pos)
newTyper(context.make(templ, self.typeSymbol, decls)).typedRefinement(templ)
templ updateAttachment CompoundTypeTreeOriginalAttachment(parents1, Nil) // stats are set elsewhere
- tree setType self
+ tree setType (if (templ.exists(_.isErroneous)) ErrorType else self) // Being conservative to avoid SI-5361
}
}
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4 test/files/neg/t3614.check
@@ -1,4 +1,4 @@
-t3614.scala:2: error: class type required but AnyRef{def a: Int} found
+t3614.scala:2: error: only declarations allowed here
def v = new ({ def a=0 })
- ^
+ ^
one error found
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4 test/files/neg/t5361.check
@@ -0,0 +1,4 @@
+t5361.scala:2: error: only declarations allowed here
+ val x : { val self = this } = new { self => }
+ ^
+one error found
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3 test/files/neg/t5361.scala
@@ -0,0 +1,3 @@
+class A {
+ val x : { val self = this } = new { self => }
+}

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