[cxx-abi-dev] Function descriptors in vtable

[Noam Lampert]

Sorry, 
It took me too long to figure out that my proposed solution here can't
work.
What could be done is
    modify_vtable(funcdescriptor vt[], int nfuncs) {
 	   for (i = 0; i < nfuncs; i++) {
	         void *p = malloc(sizeof(funcdescriptor));
		   *p = vt[i];
	         vt[i]->GP = p;
	         vt[i]->codeptr = &stub;
      	}
Sorry about the confusion.

Noam

P.S. I am still interested in a more elegant solution ;-)

> -----Original Message-----
> From: Noam Lampert [mailto:noaml at mainsoft.com]
> Sent: Wednesday, January 22, 2003 10:22 AM
> To: 'Cary Coutant'; 'Mark Mitchell'
> Cc: cxx-abi-dev at codesourcery.com
> Subject: RE: [cxx-abi-dev] Function descriptors in vtable
> 
> Hi Mark, Cary,
> 
> Your solution is in fact very elegant. I enjoyed reading it.
> 
> If I understood it correctly, it solves very well the problem of
> defining an explicit vtable in C, and using it either from C or from
> C++.
> 
> However, if the vtable was created by the C++ compiler, using it in C
is
> still very hard.
> 
> If the memory in which the vtable resides is writeable, there might be
a
> solution that involves modifying the vtable in runtime:
>    modify_vtable(funcdescriptor vt[], int nfuncs) {
> 	   for (i = 0; i < nfuncs; i++) {
> 			vt[i]->GP = &vt[i];
> 			vt[i]->codeptr = &stub;
> 	   }
> Is there a more elegant way to achieve this?
> 
> Noam
>