JVM crash: java.lang.VerifyError: Bad type on operand stack #14164

strelec · 2021-12-23T13:44:20Z

Compiler version

3.1.0

Minimized code

It seems that a combination of two factors trigger this bug:

skipping a parameter via named parameters
using for comprehension / lambda

class Base(a: String = "x", param: String = "")

class Child extends Base(param = {
  (for(x <- Seq("a")) yield x)
  "param"
})

new Child

Output

java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    Playground$Child.<init>()V @25: invokedynamic
  Reason:
    Type uninitializedThis (current frame, stack[1]) is not assignable to 'Playground$Child'

Looks somewhat siliar to #2163

Expectation

Code runs with no output.

som-snytt · 2021-12-24T17:32:20Z

My copy/paste skills are getting rusty.

➜  scala i14164.scala
Child@839755f
➜  cat i14164.scala

class Base(a: String = "x", param: String = "")

class Child extends Base(param = {
  (for(x <- Seq("a")) yield x)
  "param"
})

@main def test() = println {
  new Child
}
➜  java -version
openjdk version "17.0.1" 2021-10-19
OpenJDK Runtime Environment (build 17.0.1+12-39)
OpenJDK 64-Bit Server VM (build 17.0.1+12-39, mixed mode, sharing)
➜  scalac -version
Scala compiler version 3.1.0 -- Copyright 2002-2021, LAMP/EPFL

strelec · 2021-12-24T23:37:48Z

https://scastie.scala-lang.org/HeFyLgu5QPuWoAkfgfgRMg

som-snytt · 2021-12-25T07:14:21Z

Reproducer

package api {
  package object runtime {
    trait ScastieApp extends App
  }
}

import _root_.api.runtime._
object Playground extends ScastieApp {
  class Base(a: String = "x", param: String = "")

  class Child extends Base(param = {
    (for(x <- Seq("a")) yield x)
    "param"
  })

  new Child
}
object Main {
  val playground = Playground
  def main(args: Array[String]): Unit = {
    playground.main(Array())
  }
}

App is not involved.

object Playground {
  class Base(a: String = "x", param: String = "")

  class Child extends Base(param = {
    (for(x <- Seq("a")) yield x)
    "param"
  })

  new Child
}
@main def test() = Playground

says

➜  scala i14164d.scala
Exception in thread "main" java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    Playground$Child.<init>()V @25: invokedynamic
  Reason:
    Type uninitializedThis (current frame, stack[1]) is not assignable to 'Playground$Child'
  Current Frame:
    bci: @25
    flags: { flagThisUninit }
    locals: { uninitializedThis }
    stack: { 'scala/collection/SeqOps', uninitializedThis }
  Bytecode:
    0000000: b200 14b6 0018 b200 1d04 bd00 1f59 0312
    0000010: 2153 b600 25b6 002b 2aba 003f 0000 b900
    0000020: 4502 0057 1247 4cb2 004a b600 4e4d 2a2c
    0000030: 2bb7 0051 b1

        at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
        at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3402)
        at java.base/java.lang.Class.getMethodsRecursive(Class.java:3543)
        at java.base/java.lang.Class.getMethod0(Class.java:3529)
        at java.base/java.lang.Class.getMethod(Class.java:2225)
        at dotty.tools.scripting.ScriptingDriver.collectMainMethods$3(ScriptingDriver.scala:79)
        at dotty.tools.scripting.ScriptingDriver.$anonfun$3(ScriptingDriver.scala:88)
        at scala.collection.immutable.List.flatMap(List.scala:293)
        at dotty.tools.scripting.ScriptingDriver.detectMainClassAndMethod(ScriptingDriver.scala:89)
        at dotty.tools.scripting.ScriptingDriver.compileAndRun(ScriptingDriver.scala:34)
        at dotty.tools.scripting.Main$.main(Main.scala:43)
        at dotty.tools.MainGenericRunner$.run$1(MainGenericRunner.scala:168)
        at dotty.tools.MainGenericRunner$.main(MainGenericRunner.scala:175)
        at dotty.tools.MainGenericRunner.main(MainGenericRunner.scala)

odersky · 2022-03-13T17:58:37Z

This looks like a duplicate of an issue I fixed recently. I verified that this works now.

griggt · 2022-03-13T18:12:34Z

I verified that this works now.

It still blows up for me:

Welcome to Scala 3.1.3-RC1-bin-SNAPSHOT-nonbootstrapped-git-5626f25 (1.8.0_292, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.

scala> class Base(a: String = "x", param: String = "")
     | 
     | class Child extends Base(param = {
     |   (for(x <- Seq("a")) yield x)
     |   "param"
     | })
     | 
     | new Child
// defined class Base
// defined class Child
java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    rs$line$1$Child.<init>()V @25: invokedynamic
  Reason:
    Type uninitializedThis (current frame, stack[1]) is not assignable to 'rs$line$1$Child'
  Current Frame:
    bci: @25
    flags: { flagThisUninit }
    locals: { uninitializedThis }
    stack: { 'scala/collection/SeqOps', uninitializedThis }
  Bytecode:
    0x0000000: b200 13b6 0017 b200 1c04 bd00 1e59 0312
    0x0000010: 2053 b600 24b6 002a 2aba 003e 0000 b900
    0x0000020: 4402 0057 1246 4cb2 0049 b600 4d4d 2a2c
    0x0000030: 2bb7 0050 b1

  ... 65 elided

som-snytt · 2022-03-13T18:17:13Z

It compiles but my local dotty still says

➜  snips ~/projects/dotty/bin/scala i14164d.scala
Exception in thread "main" java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    Playground$Child.<init>()V @25: invokedynamic
  Reason:
    Type uninitializedThis (current frame, stack[1]) is not assignable to 'Playground$Child'
  Current Frame:
    bci: @25
    flags: { flagThisUninit }
    locals: { uninitializedThis }
    stack: { 'scala/collection/SeqOps', uninitializedThis }
  Bytecode:
    0000000: b200 14b6 0018 b200 1d04 bd00 1f59 0312
    0000010: 2153 b600 25b6 002b 2aba 003f 0000 b900
    0000020: 4502 0057 1247 4cb2 004a b600 4e4d 2a2c
    0000030: 2bb7 0051 b1

        at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
        at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3402)
        at java.base/java.lang.Class.getMethodsRecursive(Class.java:3543)
        at java.base/java.lang.Class.getMethod0(Class.java:3529)
        at java.base/java.lang.Class.getMethod(Class.java:2225)
        at dotty.tools.scripting.Util$.collectMainMethods$1(Util.scala:37)
        at dotty.tools.scripting.Util$.$anonfun$3(Util.scala:46)
        at scala.collection.immutable.List.flatMap(List.scala:293)
        at dotty.tools.scripting.Util$.detectMainClassAndMethod(Util.scala:47)
        at dotty.tools.scripting.ScriptingDriver.compileAndRun(ScriptingDriver.scala:28)
        at dotty.tools.scripting.Main$.main(Main.scala:45)
        at dotty.tools.MainGenericRunner$.run$1(MainGenericRunner.scala:248)
        at dotty.tools.MainGenericRunner$.main(MainGenericRunner.scala:267)
        at dotty.tools.MainGenericRunner.main(MainGenericRunner.scala)

where

➜  snips cat i14164d.scala

object Playground:
  class Base(a: String = "x", param: String = "")

  class Child extends Base(param = {
    for (x <- Seq("a")) yield x
    "param"
  })
end Playground
@main def test() = Playground

I have not yet re-spooled whatever insight I may have had last year. I just typed in the command at the prompt.

Oh, I guess it's a problem induced by scripting, because normally:

➜  snips ~/projects/dotty/bin/scalac -d /tmp i14164d.scala
resolveOverloaded List(TermRef(TermRef(ThisType(TypeRef(NoPrefix,module class scala)),object Predef),method println), TermRef(TermRef(ThisType(TypeRef(NoPrefix,module class scala)),object Predef),method println)) FunProto(Ident(Playground) => class dotty.tools.dotc.typer.ProtoTypes$CachedIgnoredProto)
resolveOverloaded.narrowedApplicable List(TermRef(TermRef(ThisType(TypeRef(NoPrefix,module class scala)),object Predef),method println))
➜  snips ~/projects/dotty/bin/scala -cp /tmp test
Playground$@62e136d3

where my extra debug is unrelated. I added a println out of paranoia.

odersky · 2022-03-13T18:20:39Z

I tried with a standalone application, not a script. @griggt @som-snytt Does that also crash for you?

som-snytt · 2022-03-13T18:20:54Z

@griggt jinx. The other family members were shuffling out the door so I didn't hit the button first.

Also I just re-re-ran with a clean repo, it fails only with scala foo.scala, not compile and run.

odersky · 2022-03-13T18:21:51Z

So should this be area:repl then?

som-snytt · 2022-03-13T18:22:33Z

The script runner is not the REPL! he said, defensively.

unless @griggt has already fixed it, I'll take a look today.

griggt · 2022-03-13T18:30:32Z

@som-snytt go for it!

It seems to me that the failure only occurs in presence of the wrapper object injected by the REPL / Scastie?

strelec · 2022-04-12T22:06:58Z

This is not just REPL, I am getting this error with production code.

som-snytt · 2022-04-12T22:45:53Z

@strelec I will get back to this. To fail, it needs both the enclosing outer template and to force loading the Child. (My @main skipped new Child, but the reflective runner induced the verifier.)

I did check that ScriptingDriver produces the same trees, it's just running it differently.

Also the script runner is not the REPL.

Super calls with default and named parameters can have lifted arguments in val defs preceding the constructor call. If these are complex, we need to hoist them out as well. Fixes scala#14164

odersky · 2022-04-13T08:11:33Z

I found the root cause: We forgot about lifted parameters when hoisting out supercall arguments.

Super calls with default and named parameters can have lifted arguments in val defs preceding the constructor call. If these are complex, we need to hoist them out as well. Fixes scala#14164

strelec added the itype:bug label Dec 23, 2021

odersky closed this as completed Mar 13, 2022

odersky reopened this Mar 13, 2022

odersky assigned som-snytt Mar 13, 2022

odersky added the area:repl label Mar 13, 2022

odersky mentioned this issue Apr 13, 2022

Also hoist lifted arguments in super calls #14919

Merged

dwijnand added area:repl area:transform and removed area:repl labels Apr 16, 2022

dwijnand closed this as completed in #14919 Apr 16, 2022

Kordyjan added this to the 3.2.0 milestone Aug 1, 2023

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JVM crash: java.lang.VerifyError: Bad type on operand stack #14164

JVM crash: java.lang.VerifyError: Bad type on operand stack #14164

strelec commented Dec 23, 2021

som-snytt commented Dec 24, 2021

strelec commented Dec 24, 2021

som-snytt commented Dec 25, 2021

odersky commented Mar 13, 2022

griggt commented Mar 13, 2022

som-snytt commented Mar 13, 2022

odersky commented Mar 13, 2022 •

edited

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som-snytt commented Mar 13, 2022 •

edited

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odersky commented Mar 13, 2022

som-snytt commented Mar 13, 2022 •

edited

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griggt commented Mar 13, 2022

strelec commented Apr 12, 2022

som-snytt commented Apr 12, 2022

odersky commented Apr 13, 2022

JVM crash: java.lang.VerifyError: Bad type on operand stack #14164

JVM crash: java.lang.VerifyError: Bad type on operand stack #14164

Comments

strelec commented Dec 23, 2021

Compiler version

Minimized code

Output

Expectation

som-snytt commented Dec 24, 2021

strelec commented Dec 24, 2021

som-snytt commented Dec 25, 2021

odersky commented Mar 13, 2022

griggt commented Mar 13, 2022

som-snytt commented Mar 13, 2022

odersky commented Mar 13, 2022 • edited Loading

som-snytt commented Mar 13, 2022 • edited Loading

odersky commented Mar 13, 2022

som-snytt commented Mar 13, 2022 • edited Loading

griggt commented Mar 13, 2022

strelec commented Apr 12, 2022

som-snytt commented Apr 12, 2022

odersky commented Apr 13, 2022

odersky commented Mar 13, 2022 •

edited

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som-snytt commented Mar 13, 2022 •

edited

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som-snytt commented Mar 13, 2022 •

edited

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