groovy

Expecting to find object/array on stack

Details

  • Type: Bug Bug
  • Status: Closed Closed
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: 1.5.5, 1.6, 1.6.4, 1.6.5
  • Fix Version/s: 1.6.6, 1.7-rc-1
  • Component/s: None
  • Labels:
    None
  • Number of attachments :
    1

Description

Repro:
Compile and run the following:

class Test
{
        String string
        URI[] uris

        public Test(String string, URI[] uris)
        {
                this.string = string
                this.uris = uris
        }

        public Test(String string, List uris)
        {
                this(string, uris.collect { new URI(it) } as URI[])
        }

        public static void main(String[] args)
        {
                def test = new Test('hello', ["world"])
                println test.string
                println test.strings
        }
}

Observed Result:

$ groovyc Test.groovy
$ groovy Test
Caught: java.lang.VerifyError: (class: Test, method: <init> signature: (Ljava/lang/String;Ljava/util/List;)V) Expecting to find object/array on stack

Expected Result:

hello
[world]

Activity

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Suk-Hyun Cho added a comment -

Sorry, it should be "println test.uris" at the end of the main method, and the expected result is

hello
{world}

A work-around is to refactor out 

uris.collect { new URI(it) } as URI[]

as a method and call it:

this(string, toUriArray(uris))
Show
Suk-Hyun Cho added a comment - Sorry, it should be "println test.uris" at the end of the main method, and the expected result is hello {world} A work-around is to refactor out uris.collect { new URI(it) } as URI[] as a method and call it: this (string, toUriArray(uris))
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Roshan Dawrani added a comment -

Trimmed and trimmed and here is the bare minimum snippet that is reproducing the issue:

class Test
{
    public Test(cl) {}

    public Test()
    {
        this({1})
    }
}

new Test()

Haven't gone beyond shortening it yet, but issue may be related to "this" reference not being ready yet in ."this(

{1}

)" - just a guess at this point though.

Show
Roshan Dawrani added a comment - Trimmed and trimmed and here is the bare minimum snippet that is reproducing the issue: class Test { public Test(cl) {} public Test() { this ({1}) } } new Test() Haven't gone beyond shortening it yet, but issue may be related to "this" reference not being ready yet in ."this( {1} )" - just a guess at this point though.
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Roshan Dawrani added a comment -

I am wondering if the fix here may be to not allow in-line closure definition while invoking a constructor from another constructor.

Groovy does not allow this(this), super(this), etc in constructorsGROOVY-3128 and doing this (

{1}) or super ({1}

) is internally the same thing because of this references being passed to the closure constructor.

Show
Roshan Dawrani added a comment - I am wondering if the fix here may be to not allow in-line closure definition while invoking a constructor from another constructor. Groovy does not allow this(this), super(this), etc in constructors GROOVY-3128 and doing this ( {1}) or super ({1} ) is internally the same thing because of this references being passed to the closure constructor.
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blackdrag blackdrag added a comment -

in "this(

{1}

)" the Closure needs an owner. The rationale here is to use the class instead of this, because all that is inside this() is to be ahndled as a static context and closures are allowed in a static context. So the code should have worked.

Show
blackdrag blackdrag added a comment - in "this( {1} )" the Closure needs an owner. The rationale here is to use the class instead of this, because all that is inside this() is to be ahndled as a static context and closures are allowed in a static context. So the code should have worked.
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Roshan Dawrani added a comment -

Yes, I had noticed for non-closure usage within this() that it uses the static context. Thanks for extending that understanding to closure's owner.

Currently the closure class instance is being created with "this" as the owner and not the class. I will look around that and see if I am able to change the owner to class object to see if that helps with this error.

Once it goes inside class loading and verification by the JVM, it becomes difficult (for me) to pinpoint the exact spot where the issue is coming from. Wish I could have a peek inside class loading/verifier too.

Show
Roshan Dawrani added a comment - Yes, I had noticed for non-closure usage within this() that it uses the static context. Thanks for extending that understanding to closure's owner. Currently the closure class instance is being created with "this" as the owner and not the class. I will look around that and see if I am able to change the owner to class object to see if that helps with this error. Once it goes inside class loading and verification by the JVM, it becomes difficult (for me) to pinpoint the exact spot where the issue is coming from. Wish I could have a peek inside class loading/verifier too.
Hide
Permalink
Roshan Dawrani added a comment -

Fixed by extending the static context to closures defined in special calls within constructors.

Thanks for the hint, Jochen.

Show
Roshan Dawrani added a comment - Fixed by extending the static context to closures defined in special calls within constructors. Thanks for the hint, Jochen.

People

  • Assignee:
    Roshan Dawrani
    Reporter:
    Suk-Hyun Cho
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Dates

  • Created:
    Updated:
    Resolved: