Weird Regression with 224ee39 (Vec issue)

[seldridge]

I'm getting a weird regression with 224ee39 (checked via bisect), but I haven't been able to get an MWE that actually trips. I have a Vec(Seq.fill(n)(Module(new MyMod).io)) and repeated assignment with more than 4 statements causes the reflection to go nuts.

The exact structure is the following (from ripping out all the extraneous code of an internal version of the original):

class ProcessingElementTableBase(implicit p: Parameters) extends DanaModule()(p) {
  val io = IO(new PETableInterface)

  val pe = Vec(Seq.fill(p(PeTableNumEntries))(Module(new ProcessingElementLearn).io))

  pe(UInt(0)).req.valid := Bool(true)
  pe(UInt(0)).req.valid := Bool(true)
  pe(UInt(0)).req.valid := Bool(true)
  pe(UInt(0)).req.valid := Bool(true)
  // The next line (148) breaks it
  pe(UInt(0)).req.valid := Bool(true)
}

// Line 159 is the "extends" part here
class ProcessingElementTableLearn(implicit p: Parameters)
    extends ProcessingElementTableBase()(p)

java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
	at util.HasGeneratorUtilities$$anonfun$2.apply(GeneratorUtils.scala:47)
	at util.HasGeneratorUtilities$$anonfun$2.apply(GeneratorUtils.scala:44)
	at chisel3.core.Module$.do_apply(Module.scala:29)
	at chisel3.Driver$$anonfun$elaborate$1.apply(Driver.scala:190)
	at chisel3.Driver$$anonfun$elaborate$1.apply(Driver.scala:190)
	at chisel3.internal.Builder$$anonfun$build$1.apply(Builder.scala:194)
	at chisel3.internal.Builder$$anonfun$build$1.apply(Builder.scala:192)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:58)
	at chisel3.internal.Builder$.build(Builder.scala:192)
	at chisel3.Driver$.elaborate(Driver.scala:190)
Caused by: java.lang.reflect.InvocationTargetException
	at sun.reflect.GeneratedConstructorAccessor49.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
	at util.ParameterizedBundle.cloneType(Misc.scala:10)
	at util.ParameterizedBundle.cloneType(Misc.scala:7)
	at chisel3.core.Aggregate.cloneTypeWidth(Aggregate.scala:18)
	at chisel3.core.Aggregate.cloneTypeWidth(Aggregate.scala:17)
	at chisel3.core.Vec$$anonfun$3.apply(Aggregate.scala:69)
	at chisel3.core.Vec$$anonfun$3.apply(Aggregate.scala:69)
	at chisel3.core.Vec.apply(Aggregate.scala:195)
	at dana.ProcessingElementTableBase.<init>(ProcessingElementTable.scala:148)
	at dana.ProcessingElementTableLearn.<init>(ProcessingElementTable.scala:155)
	at dana.Dana$$anonfun$7.apply(Dana.scala:264)
	at dana.Dana$$anonfun$7.apply(Dana.scala:264)
Caused by: java.lang.ClassNotFoundException: sun.reflect.GeneratedConstructorAccessor49
	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:195)
	at chisel3.internal.ErrorLog.chisel3$internal$ErrorLog$$isUserCode$1(Error.scala:53)
	at chisel3.internal.ErrorLog$$anonfun$1.apply(Error.scala:56)
	at chisel3.internal.ErrorLog$$anonfun$1.apply(Error.scala:56)
	at scala.collection.IndexedSeqOptimized$$anonfun$indexWhere$1.apply(IndexedSeqOptimized.scala:204)
	at scala.collection.IndexedSeqOptimized$$anonfun$indexWhere$1.apply(IndexedSeqOptimized.scala:204)
	at scala.collection.IndexedSeqOptimized$class.segmentLength(IndexedSeqOptimized.scala:195)
java.lang.RuntimeException: Nonzero exit code: 1
	at scala.sys.package$.error(package.scala:27)
	at sbt.BuildCommon$$anonfun$toError$1.apply(Defaults.scala:2077)
	at sbt.BuildCommon$$anonfun$toError$1.apply(Defaults.scala:2077)
	at scala.Option.foreach(Option.scala:236)
	at sbt.BuildCommon$class.toError(Defaults.scala:2077)
	at sbt.Defaults$.toError(Defaults.scala:39)
	at sbt.Defaults$$anonfun$runMainTask$1$$anonfun$apply$36$$anonfun$apply$37.apply(Defaults.scala:740)
	at sbt.Defaults$$anonfun$runMainTask$1$$anonfun$apply$36$$anonfun$apply$37.apply(Defaults.scala:738)
	at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
	at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
	at sbt.std.Transform$$anon$4.work(System.scala:63)
	at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:228)
	at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:228)
	at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)

However, since I can't get an equivalent MWE failing in a less cluttered environment, the issue could be related to some interaction with something else...

[seldridge]

A few more details (which are technically just interpretations of/elaborations on the stack trace). I'm importing chisel3._ in the above module. The req interface is decoupled and its data inherits from ParameterizedBundle of rocketcihp.util which imports Chisel._ (possibly related to @aswaterman's warning in 224ee39).

After digging a bit, it looks like this.getClass.getConstructors.head.newInstance(p).asInstanceOf[this.type] in ParameterizedBundle is barfing with a java.lang.ClassNotFoundException (checked by catching the exception in ParameterizedBundle and running getTargetException on it):

Caused by: java.lang.Exception: WTF? java.lang.ClassNotFoundException: sun.reflect.GeneratedConstructorAccessor15
    at chisel3.compatibility.throwException$.apply(throwException.scala:11)
    at util.ParameterizedBundle.cloneType(Misc.scala:18)
    at util.ParameterizedBundle.cloneType(Misc.scala:7)

I'm at a loss as to why this is dependent on the number of times that I run the dynamically indexed read method of Vec, however...

[seldridge]

And, I have a rough fix: The file declaring the class for req needs to use the compatibility layer and import Chisel._.

If somebody gets the time, could you fill me in on what's likely going on here?

I do realize I've been living precariously on the edge of advised/sane adoption of alpha (now beta!) tools, but I appreciate all the help.

[colinschmidt]

I was unable to reproduce this with simple types in current chisel3

  val adders = Vec(Seq.fill(4)(Module(new FullAdder).io))                                                                                                     
  adders(UInt(0)).cin := UInt(1)                                                                                                                              
  adders(UInt(0)).cin := UInt(1)                                                                                                                              
  adders(UInt(0)).cin := UInt(1)                                                                                                                              
  adders(UInt(0)).cin := UInt(1)
  adders(UInt(0)).cin := UInt(1) 

works fine.

[jackkoenig]

@seldridge I'm going to close this, please reopen (and help us reproduce it) if it's still a problem