Re: [Opencxx-users] InsertBeforeStatement doesn't work when called from the context of a ClassBodyWalker...

[Grzegorz J. <ja...@ac...>]

Scott Shumaker wrote:
> I've been writing some code with OpenC++, and have run into the
> following problem:
> 
> testClass class A
> {
>    int mData;
>    void Foo()
>    {
>       mData = 7;
>    }
> };
> 
> I've written a TranslateMemberWrite for testClass, which gets called
> when mData = 7 is referenced.  However, when I call
> InsertBeforeStatement with some additional code, nothing gets
> inserted.
> 
> On the other hand, this DOES work:
> 
> class A
> {
>    int mData;
>    void Foo();
> };
> 
> 
> void A::Foo()
> {
>    mData = 7;
> }
> 
> Looking through the code, the problem arises in ClassWalker.cc, line
> 757 (your line #s may be slightly different.  The code in question is
> as follows:
> 
> 	metaobject = GetClassMetaobject(type);
> 	if(metaobject != 0){
> 	    exp2 = metaobject->TranslateMemberWrite(env, object, op,
> 						    member, assign_op, right);
> 	    return CheckMemberEquiv(exp, exp2);
> 	}
>     }
>     else if((scope = env->IsMember(left)) != 0){
> 	metaobject = scope->IsClassEnvironment();
> 	if(metaobject != 0){
> 	    exp2 = metaobject->TranslateMemberWrite(env, left, Second(exp),
> 						    right);       
> 
> 	    return CheckEquiv(exp, exp2);
> 	}
> 
> The code has dropped into the else if case.  Looking at the variables,
> the environment variable env has a ClassBodyWalker, while the current
> context of the function is in a ClassWalker.  The
> InsertBeforeStatement thus inserts the code into the ClassBodyWalker's
> before_function list, which is never applied or copied over to the
> ClassWalker's before_function list, so it never gets inserted.
> 
> This probably would happen with any other code you write inside of an
> inlined function body - InsertBeforeStatement, etc wouldn't work.
> 
> Any suggestions for a fix?  

Sorry, I don't have much time to look into it now. Can you get hold on 
the right walker at the point where TranslateMemberWrite is called?

BR
Grzegorz