suppressing repetitive warnings

Author: willerf

compiler/src/dotty/tools/dotc/transform/init/Objects.scala

@@ -1734,16 +1734,24 @@ object Objects:
       if cls.isAllOf(Flags.JavaInterface) then Bottom
       else evalType(tref.prefix, thisV, klass, elideObjectAccess = cls.isStatic)
 
+  val mutateErrorSet: mutable.Set[(ClassSymbol, ClassSymbol)] = mutable.Set.empty
   def errorMutateOtherStaticObject(currentObj: ClassSymbol, otherObj: ClassSymbol)(using Trace, Context) =
-    val msg =
-      s"Mutating ${otherObj.show} during initialization of ${currentObj.show}.\n" +
-      "Mutating other static objects during the initialization of one static object is forbidden. " + Trace.show
+    if mutateErrorSet.contains((currentObj, otherObj)) then ()
+    else
+      mutateErrorSet += ((currentObj, otherObj))
+      val msg =
+        s"Mutating ${otherObj.show} during initialization of ${currentObj.show}.\n" +
+        "Mutating other static objects during the initialization of one static object is forbidden. " + Trace.show
 
-    report.warning(msg, Trace.position)
+      report.warning(msg, Trace.position)
 
+  val readErrorSet: mutable.Set[(ClassSymbol, ClassSymbol)] = mutable.Set.empty
   def errorReadOtherStaticObject(currentObj: ClassSymbol, otherObj: ClassSymbol)(using Trace, Context) =
-    val msg =
-      "Reading mutable state of " + otherObj.show + " during initialization of " + currentObj.show + ".\n" +
-      "Reading mutable state of other static objects is forbidden as it breaks initialization-time irrelevance. " + Trace.show
+    if readErrorSet.contains((currentObj, otherObj)) then ()
+    else
+      readErrorSet += ((currentObj, otherObj))
+      val msg =
+        "Reading mutable state of " + otherObj.show + " during initialization of " + currentObj.show + ".\n" +
+        "Reading mutable state of other static objects is forbidden as it breaks initialization-time irrelevance. " + Trace.show
 
-    report.warning(msg, Trace.position)
+      report.warning(msg, Trace.position)