-YoptTrace takes a package/Class.method parameter

2 files changed, 3 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala
index 7a1dcd9ec6..c1fdb7eb59 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala
@@ -230,7 +230,8 @@ class LocalOpt[BT <: BTypes](val btypes: BT) {
     // for local variables in dead blocks. Maybe that's a bug in the ASM framework.
 
     var currentTrace: String = null
-    def traceIfChanged(optName: String): Unit = if (compilerSettings.YoptTrace.value) {
+    val doTrace = compilerSettings.YoptTrace.isSetByUser && compilerSettings.YoptTrace.value == ownerClassName + "." + method.name
+    def traceIfChanged(optName: String): Unit = if (doTrace) {
       val after = AsmUtils.textify(method)
       if (currentTrace != after) {
         println(s"after $optName")
diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
index d6ca0125ea..20e2c4346f 100644
--- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
@@ -319,7 +319,7 @@ trait ScalaSettings extends AbsScalaSettings
   def YoptWarningNoInlineMissingBytecode            = YoptWarnings.contains(YoptWarningsChoices.noInlineMissingBytecode)
   def YoptWarningNoInlineMissingScalaInlineInfoAttr = YoptWarnings.contains(YoptWarningsChoices.noInlineMissingScalaInlineInfoAttr)
 
-  val YoptTrace = BooleanSetting("-YoptTrace", "trace optimizer progress")
+  val YoptTrace = StringSetting("-YoptTrace", "package/Class.method", "Trace the optimizer progress for a specific method.", "")
 
   private def removalIn212 = "This flag is scheduled for removal in 2.12. If you have a case where you need this flag then please report a bug."