Re: Differences in c and c++ anon typedefs

[Brendon Costa <brendon at christian dot net>]

Andrew Pinski wrote:
> Again C has different rules from C++.
> In C, the following two TUs combined together are still valid code while in C++,
> they are invalid.
> 
> tu1.c:
> 
> struct a
> {
>   int t;
> };
> void f(struct a);
> 
> ---------------- cut ---------------------
> tu2.c:
> 
> typedef struct
> {
>   int t;
> }b;
> void f(b a);
> ---------------- cut ---------------------
> 

I think I am going to have to use a non-optimal solution for function
pointer type matches. I am creating a pessimistic/over-expanded
callgraph by saying that a function pointer call MAY call any function
whose function pointer type matches the call and whose address has been
taken somewhere in the source code. So maybe I can make it even more
pessimistic in the C case and match all structs/unions as being the
"same" for the purposes of testing function pointer equality.

Maybe it is also possible to somehow generate a "type string" based on
the contents of the struct/union in C, however I am not sure how I would
get that to inter-operate with C++ since C++ may treat two structures
with the same contents as different types. I might just go for the
pessimistic match first and look at improving things later on once the
rest of it is all up and going.

Thanks for the input,
Brendon.