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<chapter id="miscellaneous" xreflabel="Miscellaneous Changes">
<title>Other Changes in AspectJ 5</title>
<sect1>
<title>Pointcuts</title>
<sect2>
<title>Binding of formals</title>
<para>
AspectJ 5 is more liberal than AspectJ 1.2.1 in accepting pointcut expressions
that bind context variables in more than one location. For example, AspectJ
1.2.1 does not allow:
</para>
<programlisting><![CDATA[
pointcut foo(Foo foo) : (execution(* *(..)) && this(foo) ) ||
(set(* *) && target(foo));
]]></programlisting>
<para>
whereas this expression is permitted in AspectJ 5. Each context variable must
be bound exactly once in each branch of a disjunction, and the disjunctive branches
must be mutually exclusive. In the above example for instance, no join point
can be both an execution join point and a set join point so the two branches
are mutually exclusive.
</para>
</sect2>
<sect2>
<title>Additional lint warnings</title>
<para>
Discuss detection of common errors -> warning/error, eg. conjunction of more than one
kind of join point. Differing numbers of args in method signature / args / @args /
@parameters.
</para>
</sect2>
</sect1>
<sect1 id="declare-soft">
<title>Declare Soft</title>
<para>
The semantics of the <literal>declare soft</literal> statement have been
refined in AspectJ 5 to only soften exceptions that are not already runtime
exceptions. If the exception type specified in a declare soft statement is <literal>RuntimeException</literal>
or a subtype of <literal>RuntimeException</literal> then a new XLint warning will be issued:</para>
<programlisting><![CDATA[
declare soft : SomeRuntimeException : execution(* *(..));
>> "SomeRuntimeException will not be softened as it is already a RuntimeException" [XLint:runtimeExceptionNotSoftened]
]]></programlisting>
<para>
This XLint message can be controlled by setting the <literal>runtimeExceptionNotSoftened</literal> XLint parameter.
</para>
<para>
If the exception type specified in a declare soft statement is a super type of <literal>RuntimeException</literal>
(such as <literal>Exception</literal> for example) then any <i>checked</i> exception thrown at a matched join point,
where the exception is an instance of the softened exception, will be softened to an
<literal>org.aspectj.lang.SoftException</literal>.
</para>
<programlisting><![CDATA[
public aspect SoftenExample {
declare soft : Exception : execution(* Foo.*(..));
}
class Foo {
public static void main(String[] args) {
Foo foo = new Foo();
foo.foo();
foo.bar();
}
void foo() throws Exception {
throw new Exception(); // this will be converted to a SoftException
}
void bar() throws Exception {
throw new RuntimeException(); // this will remain a RuntimeException
}
}
]]></programlisting>
</sect1>
</chapter>
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