SI-7783 Don't issue deprecation warnings for inferred TypeTrees

Deprecation checks in RefChecks were looking into all TypeTrees
to find references to deprecated type aliases. However, when the
compiler infers a type argument or type of a member it creates
a TypeTree (with a null original) that was also leading to warnings.

I ran into this problem often when upgrading a build from SBT 0.12
to 0.13: a plugin I was using used the deprecated type alias, and I
suffered transitively when I used methods from its API.

This commit disables the checks for inferred TypeTree-s.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 83afb3a728..081f7a8696 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1515,7 +1515,11 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
 
     private def checkTypeRef(tp: Type, tree: Tree, skipBounds: Boolean) = tp match {
       case TypeRef(pre, sym, args) =>
-        checkDeprecated(sym, tree.pos)
+        tree match {
+          case tt: TypeTree if tt.original == null => // SI-7783 don't warn about inferred types
+          case _ =>
+            checkDeprecated(sym, tree.pos)
+        }
         if(sym.isJavaDefined)
           sym.typeParams foreach (_.cookJavaRawInfo())
         if (!tp.isHigherKinded && !skipBounds)