Re: [ros-dev] [ros-diffs] [ekohl] 53469: [WIDL] Revert parts of r53171: Remove the -Oif flag for WIDL because the NT4 stub code generated by the current WIDL is heavily broken with respect to the range attribute and others....

[Eric Kohl]

Hello Jérôme!

>   I'm not sure about what you mean for range
> attribute, but I notice that
>  typedef [context_handle] PVOID my_handle;
>  makes widl thinks that any value of the my_handle type is passed by
>  pointer, whereas midl considers it is passed by value. 
Did you try to find the bug
in WIDL?

>   Could you be more precise about "range attributes
> and others?" please. 
I should better have written "range attributes and
probably others"!

The range attribute is used in the svcctl.idl file and enables range 
checks in rpcrt4.dll. This is a nice feature, but WIDL is messing up the 
ranges if a range attribute is used with function parameters.

For example:
DWORD Test(
     [in] SC_RPC_HANDLE hSCManager,
     [in, range(0, 1024)] DWORD dwParam1,
     [in, range(0, 255)] DWORD dwParam2);

WIDL will emit the same range type (range 0-255) for both parameters 
because the range attribute is assigned to the DWORD type and it is 
overwritten whenever a new range attribute is used with the DWORD type.
In the end all DWORD type parameters that have a range attribute will 
use the range that is used by the last DWORD type with a range attribute 
(dwParam2 in this case) in the idl file. This will cause some 'funny' 
effects if dwParam1 is greater than 255. :-/

BTW, I think it is more important to have a working RPC system in 
ReactOS than a windows-compatible one. The compatibility issues can be 
fixed later, but if you break RPC today by fixing compatibility issues 
you will render ReactOS unusable. So please be very careful when you 
make changes to rpcrt4 or WIDL.


Regards,
Eric