Bug 4440 - Incorrect System.TypeLoadException
Summary: Incorrect System.TypeLoadException
Alias: None
Product: Runtime
Classification: Mono
Component: JIT ()
Version: unspecified
Hardware: PC All
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2012-04-15 06:09 UTC by Jeroen Frijters
Modified: 2012-07-23 06:04 UTC (History)
4 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Jeroen Frijters 2012-04-15 06:09:57 UTC
Download weka-3-6-0.zip from http://sourceforge.net/projects/weka/files/weka-3-6/3.6.0/weka-3-6-0.zip/download and extract weka.jar from it.

Run ikvm (either the version that ships with Mono or a more recent):

ikvm -cp weka.jar weka.classifiers.bayes.net.search.global.GlobalScoreSearchAlgorithm

(the above all on one line)

This results in:

Exception in thread "main" java.lang.ExceptionInInitializerError
        at cli.System.Runtime.CompilerServices.RuntimeHelpers.RunClassConstructor(Unknown Source)
        at IKVM.Internal.TypeWrapper.RunClassInit(Unknown Source)
        at IKVM.NativeCode.java.lang.Class.forName0(Unknown Source)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java)
Caused by: cli.System.TypeLoadException: Could not load type 'weka.core.Tag[]' from assembly 'ikvm_dynamic_assembly__1898486584, Version=2012.415.1203.16614, Culture=neutral, PublicKeyToken=null'.

(the correct output is "Exception in thread "main" java.lang.NoSuchMethodError: main")

The IKVM runtime correctly creates the weka.core.Tag type and handles the TypeResolve event to return the proper assembly, but somehow the Mono runtime gets confused by the array type. I could not reproduce it in a trivial example.
Comment 1 Zoltan Varga 2012-04-23 07:36:25 UTC
This happens because the vtype setup for weka.core.Tag fails because of the setup_interface_offsets () mess, mono_class_setup_interface_offsets () calls it with 0 as cur_slot, meaning class->interface_offsets_packed will contain bogus values, and later calls which pass in the correct value will not update it.
Comment 2 Zoltan Varga 2012-04-23 08:37:47 UTC
Fixed in master by 628e025476f1e8781502eb9ee44bc94911229c36. We might backport the fix to the 2.10 release after some testing, since the fix involves core and pretty complex code.
Comment 3 Konrad Kruczyński 2012-07-23 04:41:40 UTC
Btw, status should be probably changed to FIXED.
Comment 4 Zoltan Varga 2012-07-23 06:04:42 UTC