.

Author: lihaoyi

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

@@ -325,6 +325,7 @@ private sealed trait XSettings:
   val XprintSuspension: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xprint-suspension", "Show when code is suspended until macros are compiled.")
   val Xprompt: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xprompt", "Display a prompt after each error (debugging option).")
   val XreplDisableDisplay: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xrepl-disable-display", "Do not display definitions in REPL.")
+  val XreplDisableBytecodeInstrumentation: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xrepl-disable-bytecode-instrumentation", "Disable bytecode instrumentation for interrupt handling in REPL.")
   val XverifySignatures: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xverify-signatures", "Verify generic signatures in generated bytecode.")
   val XignoreScala2Macros: Setting[Boolean] = BooleanSetting(AdvancedSetting, "Xignore-scala2-macros", "Ignore errors when compiling code that calls Scala2 macros, these will fail at runtime.")
   val XimportSuggestionTimeout: Setting[Int] = IntSetting(AdvancedSetting, "Ximport-suggestion-timeout", "Timeout (in ms) for searching for import suggestions when errors are reported.", 8000)

compiler/src/dotty/tools/repl/AbstractFileClassLoader.scala

@@ -21,7 +21,7 @@ import dotty.tools.repl.ReplBytecodeInstrumentation
 import java.net.{URL, URLConnection, URLStreamHandler}
 import java.util.Collections
 
-class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader) extends ClassLoader(parent):
+class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader, instrumentBytecode: Boolean = true) extends ClassLoader(parent):
   private def findAbstractFile(name: String) = root.lookupPath(name.split('/').toIndexedSeq, directory = false)
 
   // on JDK 20 the URL constructor we're using is deprecated,
@@ -58,7 +58,7 @@ class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader) exten
 
     // Instrument bytecode for everything except ReplCancel itself to avoid infinite recursion
     val bytes =
-      if name == "dotty.tools.repl.ReplCancel" then originalBytes
+      if !instrumentBytecode || name == "dotty.tools.repl.ReplCancel" then originalBytes
       else ReplBytecodeInstrumentation.instrument(originalBytes)
 
     defineClass(name, bytes, 0, bytes.length)
@@ -72,7 +72,8 @@ class AbstractFileClassLoader(val root: AbstractFile, parent: ClassLoader) exten
       if (is == null) return super.loadClass(name)
 
       try
-        val instrumentedBytes = ReplBytecodeInstrumentation.instrument(is.readAllBytes())
+        val bytes = is.readAllBytes()
+        val instrumentedBytes = if instrumentBytecode then ReplBytecodeInstrumentation.instrument(bytes) else bytes
         defineClass(name, instrumentedBytes, 0, instrumentedBytes.length)
       finally
         is.close()

compiler/src/dotty/tools/repl/Rendering.scala

@@ -72,7 +72,8 @@ private[repl] class Rendering(parentClassLoader: Option[ClassLoader] = None):
         new java.net.URLClassLoader(compilerClasspath.toArray, baseClassLoader)
       }
 
-      myClassLoader = new AbstractFileClassLoader(ctx.settings.outputDir.value, parent)
+      val instrumentBytecode = !ctx.settings.XreplDisableBytecodeInstrumentation.value
+      myClassLoader = new AbstractFileClassLoader(ctx.settings.outputDir.value, parent, instrumentBytecode)
       myClassLoader
     }
 

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -599,8 +599,9 @@ class ReplDriver(settings: Array[String],
             val prevClassLoader = rendering.classLoader()
             val jarClassLoader = fromURLsParallelCapable(
               jarClassPath.asURLs, prevClassLoader)
+            val instrumentBytecode = !ctx.settings.XreplDisableBytecodeInstrumentation.value
             rendering.myClassLoader = new AbstractFileClassLoader(
-              prevOutputDir, jarClassLoader)
+              prevOutputDir, jarClassLoader, instrumentBytecode)
 
             out.println(s"Added '$path' to classpath.")
         } catch {