[ 
https://issues.apache.org/jira/browse/BCEL-193?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jérôme Leroux updated BCEL-193:
-------------------------------
    Description: 
The following valid code raises a verify error:
{code:java}
public class TestArrayAccess01 extends XTestArray01{
    public static void test(){
        XTestArray01[] array = new TestArrayAccess01[1];
        array[0] = new XTestArray01();
    }   
}

class XTestArray01 {}
{code}

The code above will throw an {{ArrayStoreException}} at runtime but the 
generated bytecode is valid.

_The Java Virtual Machine Specification Second Edition_ is ambigous about this 
kind of issue. It states in §4.8.2 _Structural Constraints_ 
(http://docs.oracle.com/javase/specs/jvms/se5.0/html/ClassFile.doc.html#9308):
{quote}
The type of every value stored into an array of type reference by an aastore 
instruction must be assignment compatible (§2.6.7) with the component type of 
the array.
{quote}
But in the {{aastore}} opcode description, there is no reference to any kind of 
linking or verification error. The assignment compatiblity error is a runtime 
exception.

In the _Java SE 7 Edition_ of __The Java Virtual Machine Specification_, the §4 
has been modified 
(http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.9.2):
{quote}
The type of every value stored into an array by an aastore instruction must be 
a reference type.
The component type of the array being stored into by the aastore instruction 
must also be a reference type. 
{quote}

The assignment compatibility check must not be done during the verification of 
the bytecode but during its execution.

  was:
The following valid code raises a verify error:
{code:java}
public class TestArrayAccess01 extends XTestArray01{
    public static void test(){
        XTestArray01[] array = new TestArrayAccess01[1];
        array[0] = new XTestArray01();
    }   
}

class XTestArray01 {}
{code}

The code above will throw an {{ArrayStoreException}} at runtime but the 
generated bytecode is valid.

_The Java Virtual Machine Specification Second Edition_ is ambigous about this 
kind of issue. It states in §4.8.2 _Structural Constraints_ 
(http://docs.oracle.com/javase/specs/jvms/se5.0/html/ClassFile.doc.html#9308):
{quote}
The type of every value stored into an array of type reference by an aastore 
instruction must be assignment compatible (§2.6.7) with the component type of 
the array.
{quote}
But in the {{aastore}} opcode description, there is no reference to any kind of 
linking or verification error. The assignement compatiblity error is a runtime 
exception.

In the _Java SE 7 Edition_ of __The Java Virtual Machine Specification_, the §4 
has been modified 
(http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.9.2):
{quote}
The type of every value stored into an array by an aastore instruction must be 
a reference type.
The component type of the array being stored into by the aastore instruction 
must also be a reference type. 
{quote}

The assignement compatibility check must not be done during the verification of 
the bytecode but during its execution.


> aastore instruction should not raise a verify error if an assignement 
> compatiblity error is detected
> ----------------------------------------------------------------------------------------------------
>
>                 Key: BCEL-193
>                 URL: https://issues.apache.org/jira/browse/BCEL-193
>             Project: Commons BCEL
>          Issue Type: Bug
>          Components: Verifier
>    Affects Versions: 6.0
>            Reporter: Jérôme Leroux
>
> The following valid code raises a verify error:
> {code:java}
> public class TestArrayAccess01 extends XTestArray01{
>     public static void test(){
>         XTestArray01[] array = new TestArrayAccess01[1];
>         array[0] = new XTestArray01();
>     }   
> }
> class XTestArray01 {}
> {code}
> The code above will throw an {{ArrayStoreException}} at runtime but the 
> generated bytecode is valid.
> _The Java Virtual Machine Specification Second Edition_ is ambigous about 
> this kind of issue. It states in §4.8.2 _Structural Constraints_ 
> (http://docs.oracle.com/javase/specs/jvms/se5.0/html/ClassFile.doc.html#9308):
> {quote}
> The type of every value stored into an array of type reference by an aastore 
> instruction must be assignment compatible (§2.6.7) with the component type of 
> the array.
> {quote}
> But in the {{aastore}} opcode description, there is no reference to any kind 
> of linking or verification error. The assignment compatiblity error is a 
> runtime exception.
> In the _Java SE 7 Edition_ of __The Java Virtual Machine Specification_, the 
> §4 has been modified 
> (http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.9.2):
> {quote}
> The type of every value stored into an array by an aastore instruction must 
> be a reference type.
> The component type of the array being stored into by the aastore instruction 
> must also be a reference type. 
> {quote}
> The assignment compatibility check must not be done during the verification 
> of the bytecode but during its execution.



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