3 files changed, 12 insertions, 11 deletions
diff --git a/src/dotty/tools/dotc/Run.scala b/src/dotty/tools/dotc/Run.scala
index c662aabfa..928bf753a 100644
--- a/src/dotty/tools/dotc/Run.scala
+++ b/src/dotty/tools/dotc/Run.scala
@@ -31,7 +31,7 @@ class Run(comp: Compiler)(implicit ctx: Context) {
 
   /** Print summary; return # of errors encountered */
   def printSummary(): Reporter = {
-    Constraint.printMax()
+    ctx.runInfo.printMaxConstraint()
     val r = ctx.typerState.reporter
     r.printSummary
     r
diff --git a/src/dotty/tools/dotc/core/Constraint.scala b/src/dotty/tools/dotc/core/Constraint.scala
index 1df3c6ac5..010601450 100644
--- a/src/dotty/tools/dotc/core/Constraint.scala
+++ b/src/dotty/tools/dotc/core/Constraint.scala
@@ -72,13 +72,9 @@ class Constraint(val myMap: SimpleMap[PolyType, Array[Type]]) extends AnyVal wit
    *  the entries corresponding to `pt` with `entries`.
    */
   private def updateEntries(pt: PolyType, entries: Array[Type])(implicit ctx: Context) : Constraint = {
-    import Constraint._
     val res = new Constraint(myMap.updated(pt, entries))
     if (Config.checkConstraintsNonCyclic) checkNonCyclic(pt, entries)
-    if (res.myMap.size > maxSize) {
-      maxSize = res.myMap.size
-      maxConstraint = res
-    }
+    ctx.runInfo.recordConstraintSize(res)
     res
   }
 
@@ -294,9 +290,14 @@ class Constraint(val myMap: SimpleMap[PolyType, Array[Type]]) extends AnyVal wit
   }
 }
 
-object Constraint {
-  var maxSize = 0
-  var maxConstraint: Constraint = _
-  def printMax()(implicit ctx: Context) =
+trait ConstraintRunInfo { self: RunInfo =>
+  private var maxSize = 0
+  private var maxConstraint: Constraint = _
+  def recordConstraintSize(c: Constraint) =
+    if (c.myMap.size > maxSize) {
+      maxSize = c.myMap.size
+      maxConstraint = c
+    }
+  def printMaxConstraint()(implicit ctx: Context) =
     if (maxSize > 0) println(s"max constraint = ${maxConstraint.show}")
 }
diff --git a/src/dotty/tools/dotc/core/Contexts.scala b/src/dotty/tools/dotc/core/Contexts.scala
index 1d78eaf02..7ffdea1b3 100644
--- a/src/dotty/tools/dotc/core/Contexts.scala
+++ b/src/dotty/tools/dotc/core/Contexts.scala
@@ -486,7 +486,7 @@ object Contexts {
   }
 
   /** Info that changes on each compiler run */
-  class RunInfo(initctx: Context) extends ImplicitRunInfo {
+  class RunInfo(initctx: Context) extends ImplicitRunInfo with ConstraintRunInfo {
     implicit val ctx: Context = initctx
   }