[aspectc-user] Several Questions

Olaf Spinczyk Olaf.Spinczyk at informatik.uni-erlangen.de
Mon Oct 14 13:09:30 CEST 2002

Hi Dominik,

On Thursday 10 October 2002 15:25, you wrote:
> Dear All!
> Several questions concerning several topics:
> 1) callsto
> Is the "callsto"-keyword still valid in ac++?
> This
>   pointcut pc_ClassX_GETTER() = callsto("% ClassX::get%(...)");
> lets ac++ stop compilation with the error
>   error: Name `callsto' is undefined

callsto is mentioned in our papers, but not supported anymore. Do you have an 
example, where 'call' and 'execution' is not suficient?

> 2) Constructor-Tracing
> How to specify Object-Construction-Pointcuts?
> Only via constructors of inner introduced classes (as seen in
> examples/instances)?
> These
>   pointcut pc_ClassX_CONS() = call("% operator new(...)");
>   pointcut pc_ClassX_CONS() = call("% operator new()");
>   pointcut pc_ClassX_CONS() = call("% ClassX::ClassX()");
>   pointcut pc_ClassX_CONS() = call("% ClassX::ClassX(...)");
> do compile but do not bring the expected result.

Constructor tracing is not implemented yet. You can use the 'inner-function 
workaround' instead. One reason for this missing feature is that the weaving 
operation is a bit different for constructors than for ordinary functions. 
More important is the point that one constructor might call others. If a 
programmer just wants some code to be executed, which runs before an object 
of a certain class is instanciated, it is hard to declare advice in a way as 
you mentioned it above, because with "ClassX::ClassX(...)" there might be 
multiple advice code activations while with "ClassX::ClassX()" not every 
instantiation will be detected.

Concerning operator new you have found a bug. 'execution ("% operator 
new(...)")' works and call(...) should work as well. As a workaround for your 
problem you define your own 'operator new' and give advice for this. We will 
try to fix the problem as soon as possible.



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