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

[Scott S. <ssh...@gm...>]

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?  

Thanks,
Scott