Guard the check under a flag

Author: liufengyun

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -379,6 +379,7 @@ private sealed trait YSettings:
   val YnoKindPolymorphism: Setting[Boolean] = BooleanSetting("-Yno-kind-polymorphism", "Disable kind polymorphism.")
   val YexplicitNulls: Setting[Boolean] = BooleanSetting("-Yexplicit-nulls", "Make reference types non-nullable. Nullable types can be expressed with unions: e.g. String|Null.")
   val YcheckInit: Setting[Boolean] = BooleanSetting("-Ysafe-init", "Ensure safe initialization of objects")
+  val YcheckInitGlobal: Setting[Boolean] = BooleanSetting("-Ysafe-init-global", "Check safe initialization of global objects")
   val YrequireTargetName: Setting[Boolean] = BooleanSetting("-Yrequire-targetName", "Warn if an operator is defined without a @targetName annotation")
   val YrecheckTest: Setting[Boolean] = BooleanSetting("-Yrecheck-test", "Run basic rechecking (internal test only)")
   val YccDebug: Setting[Boolean] = BooleanSetting("-Ycc-debug", "Used in conjunction with captureChecking language import, debug info for captured references")
@@ -396,4 +397,3 @@ private sealed trait YSettings:
 
   val YforceInlineWhileTyping: Setting[Boolean] = BooleanSetting("-Yforce-inline-while-typing", "Make non-transparent inline methods inline when typing. Emulates the old inlining behavior of 3.0.0-M3.")
 end YSettings
-

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

@@ -37,7 +37,9 @@ class Checker extends Phase:
     val classes = traverser.getClasses()
 
     Semantic.checkClasses(classes)(using checkCtx)
-    Objects.checkClasses(classes)(using checkCtx)
+
+    if ctx.settings.YcheckInitGlobal.value then
+      Objects.checkClasses(classes)(using checkCtx)
 
     units