Merge pull request scala#12844 from dotty-staging/unpickle-param-cycle

TreeUnpickler: fix cycle involving param accessor
keynmol · Jun 18, 2021 · f003711 · f003711
2 parents b48b2c1 + 712d53b
commit f003711
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
@@ -885,7 +885,12 @@ class TreeUnpickler(reader: TastyReader,
       }
       goto(end)
       setSpan(start, tree)
-      if (!sym.isType) // Only terms might have leaky aliases, see the documentation of `checkNoPrivateLeaks`
+
+      // Dealias any non-accessible type alias in the type of `sym`. This can be
+      // skipped for types (see `checkNoPrivateLeaks` for why) as well as for
+      // param accessors since they can't refer to an inaccesible type member of
+      // the class.
+      if !sym.isType && !sym.is(ParamAccessor) then
         sym.info = ta.avoidPrivateLeaks(sym)
 
       if (ctx.settings.YreadComments.value) {

diff --git a/tests/pos/i12834.scala b/tests/pos/i12834.scala
@@ -0,0 +1,2 @@
+class A(val ref: Option[B])
+class B extends A(None)
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		class A(val ref: Option[B])
		class B extends A(None)