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https://issues.apache.org/jira/browse/BCEL-193?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14275299#comment-14275299
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Jérôme Leroux commented on BCEL-193:
------------------------------------
I don't think so. If the classfile is compliant with the specification, the
verifier must not reject it.
The {{ArrayStoreException}} is not an error ({{java.lang.Error}}) and is a
normal exception that can be caught by the application such as a
{{NullPointerException}} or a {{ClassCastException}}.
In §4.9 of _The Java Virtual Machine Specification Second Edition_ states:
{quote}
It _(the bytecode verifier)_ should certify all code generated by Sun's
compiler for the Java programming language
{quote}
Here is the example defined in the {{ArrayStoreException}} javadoc:
{code:java}
Object x[] = new String[3];
x[0] = new Integer(0);
{code}
If this code should be rejected by the verifier, then the following code
defined in {{ClassCastException}} should also:
{code:java}
Object x = new Integer(0);
System.out.println((String)x);
{code}
This kind of checks does not concern the verifier, they may be made by code
analyzer such as PMD.
> aastore instruction should not raise a verify error if an assignment
> 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
> Attachments: BCEL-193.patch, BCEL-193.zip
>
>
> 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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