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The Refchecks tree transformer transforms a nested modules that
overrides a method into a pair of symbols: the module itself, and
an module accessor that matches the overridden symbol.
[[syntax trees at end of typer]] // test1.scala
package <empty> {
abstract trait C2 extends scala.AnyRef {
def O1: Any
};
class C1 extends AnyRef with C2 {
object O1 extends scala.AnyRef
}
}
[[syntax trees at end of refchecks]] // test1.scala
package <empty> {
abstract trait C2 extends scala.AnyRef {
def O1: Any
};
class C1 extends AnyRef with C2 {
object O1 extends scala.AnyRef
@volatile <synthetic> private[this] var O1$module: C1.this.O1.type = _;
<stable> def O1: C1.this.O1.type = {
C1.this.O1$module = new C1.this.O1.type();
C1.this.O1$module
}
}
}
When constructing a TypeRef or SingleType with a prefix and and a symbol,
the factory methods internally use `rebind` to see if the provided symbol
should be replaced with an overriding symbol that is available in that prefix.
Trying this out in the REPL is a bit misleading, because even if you change
phase to `refchecks`, you won't get the desired results because the transform
is not done in an InfoTransformer.
scala> val O1 = typeOf[C1].decl(TermName("O1"))
O1: $r.intp.global.Symbol = object O1
scala> typeRef(typeOf[C2], O1, Nil)
res13: $r.intp.global.Type = C2#O1
scala> res13.asInstanceOf[TypeRef].sym.owner
res14: $r.intp.global.Symbol = class C1
But debugging the test case, we get into `rebind` during an AsSeenFrom
which is where we crashed when `suchThat` encountered the overloaded
module and module accessor symbols:
typeOf[OuterObject.Inner.type].memberType(symbolOf[InnerTrait.Collection])
...
singleTypeAsSeen(OuterTrait.this.Inner.type)
val SingleType(pre, sym) = tp
// pre = OuterTrait.this.type
// sym = OuterTrait.Inner
val pre1 = this(pre) // OuterObject.type
singleType(pre1, sym)
rebind(pre1, sym) // was crashing, now OuterObject.Inner
}
This commit excludes the module symbol from symbol lookup in the prefix in rebind.
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