Small fixes to some warnings/comment typos

interfaces/src/main/java/dotty/tools/dotc/interfaces/SourceFile.java

@@ -1,7 +1,5 @@
 package dotty.tools.dotc.interfaces;
 
-import java.io.File;
-
 /** A source file.
  *
  *  User code should not implement this interface, but it may have to

src/dotty/tools/dotc/ast/Trees.scala

@@ -48,7 +48,7 @@ object Trees {
    *     the existing tree transparently, assigning its `tpe` field,
    *     provided it was `null` before.
    *   - It is impossible to embed untyped trees in typed ones.
-   *   - Typed trees can be embedded untyped ones provided they are rooted
+   *   - Typed trees can be embedded in untyped ones provided they are rooted
    *     in a TypedSplice node.
    *   - Type checking an untyped tree should remove all embedded `TypedSplice`
    *     nodes.
@@ -855,7 +855,7 @@ object Trees {
 
     val cpy: TreeCopier
 
-    /** A class for copying trees. The copy methods avid creating a new tree
+    /** A class for copying trees. The copy methods avoid creating a new tree
      *  If all arguments stay the same.
      *
      * Note: Some of the copy methods take a context.

src/dotty/tools/dotc/transform/TreeTransform.scala

@@ -42,7 +42,7 @@ object TreeTransforms {
    *            the general dispatch overhead as opposed to the concrete work done in transformations. So that leaves us with
    *            0.2sec, or roughly 600M processor cycles.
    *
-   *            Now, to the amount of work that needs to be done. The codebase produces of about 250'000 trees after typechecking.
+   *            Now, to the amount of work that needs to be done. The codebase produces an average of about 250'000 trees after typechecking.
    *            Transformations are likely to make this bigger so let's assume 300K trees on average. We estimate to have about 100
    *            micro-transformations. Let's say 5 transformation groups of 20 micro-transformations each. (by comparison,
    *            scalac has in excess of 20 phases, and most phases do multiple transformations). There are then 30M visits
@@ -208,7 +208,7 @@ object TreeTransforms {
       if (cls.getDeclaredMethods.exists(_.getName == name)) cls != classOf[TreeTransform]
       else hasRedefinedMethod(cls.getSuperclass, name)
 
-    /** Create an index array `next` of size one larger than teh size of `transforms` such that
+    /** Create an index array `next` of size one larger than the size of `transforms` such that
      *  for each index i, `next(i)` is the smallest index j such that
      *
      *  i <= j

src/dotty/tools/dotc/typer/TypeAssigner.scala

@@ -414,7 +414,7 @@ trait TypeAssigner {
 
   def assignType(tree: untpd.SeqLiteral, elems: List[Tree], elemtpt: Tree)(implicit ctx: Context) = {
     val ownType = tree match {
-      case tree: JavaSeqLiteral => defn.ArrayOf(elemtpt.tpe)
+      case tree: untpd.JavaSeqLiteral => defn.ArrayOf(elemtpt.tpe)
       case _ => if (ctx.erasedTypes) defn.SeqType else defn.SeqType.appliedTo(elemtpt.tpe)
     }
     tree.withType(ownType)

src/strawman/collections/CollectionStrawMan4.scala

@@ -216,7 +216,7 @@ object CollectionStrawMan4 {
 
   object ListBuffer extends IterableFactory[ListBuffer] {
     def fromIterable[B](coll: Iterable[B]): ListBuffer[B] = coll match {
-      case pd @ View.Partitioned(partition: View.Partition[B]) =>
+      case pd @ View.Partitioned(partition: View.Partition[B] @unchecked) =>
         partition.distribute(new ListBuffer[B]())
         new ListBuffer[B] ++= pd.forced.get
       case _ =>
@@ -267,7 +267,7 @@ object CollectionStrawMan4 {
         Array.copy(fst.elems, fst.start, elems, 0, fst.length)
         Array.copy(snd.elems, snd.start, elems, fst.length, snd.length)
         new ArrayBuffer(elems, elems.length)
-      case pd @ View.Partitioned(partition: View.Partition[B]) =>
+      case pd @ View.Partitioned(partition: View.Partition[B] @unchecked) =>
         partition.distribute(new ArrayBuffer[B]())
         pd.forced.get.asInstanceOf[ArrayBuffer[B]]
       case c if c.knownLength >= 0 =>

test/test/ContextEscapeDetector.java

@@ -1,6 +1,5 @@
 package test;
 
-import org.junit.runner.Description;
 import org.junit.runner.Result;
 import org.junit.runner.notification.RunListener;
 import org.junit.Assert;
@@ -43,6 +42,7 @@ private static synchronized int contextsAlive() {
         return count;
     }
 
+    @SuppressWarnings("unused")
     private static volatile Object o = null;
 
     private static synchronized void forceGCHeuristic0() {
@@ -59,7 +59,7 @@ private static synchronized void forceGCHeuristic0() {
 
     private static synchronized void forceGCHeuristic1() {
         Object obj = new Object();
-        WeakReference ref = new WeakReference<Object>(obj);
+        WeakReference<Object> ref = new WeakReference<>(obj);
         obj = null;
         while (ref.get() != null) {
             System.gc();
@@ -69,7 +69,7 @@ private static synchronized void forceGCHeuristic1() {
     private static synchronized void forceGCHeuristic2() {
         try {
             Object[] arr = new Object[1024]; // upto 8 GB
-            WeakReference ref = new WeakReference<Object>(arr);
+            WeakReference<Object> ref = new WeakReference<>(arr);
             o = arr; // make sure array isn't optimized away
 
             Runtime runtime = Runtime.getRuntime();