Re: Error handling in Win32 + gnulib

[Paolo Bonzini]

On 11/27/2009 04:57 PM, Richard W.M. Jones wrote:
> (b) A call to a Winsock socket function that gnulib hasn't replaced:
> errno won't have any meaningful value and I must call WSAGetLastError.

We can add replacements for these.

> (c) A call to a non-socket Win32 function that gnulib has replaced: I
> have to go and check Gnulib to see if it sets errno (some do, some
> don't, some do only along some paths).  I need to then consider errno
> and/or GetLastError.  I have to keep checking this with every revision
> of Gnulib because it might change.

These are bugs, please report them.

> In addition, it turns out that error codes aren't compatible.
> Although Gnulib tries to define its own error numbers which are
> compatible with Win32 ones (eg. EINPROGRESS == 10036 ==
> WSAEINPROGRESS), it also uses some from the MinGW header files which
> are just plain wrong (eg. ENOMEM == 12 == ERROR_INVALID_ACCESS, MinGW
> gets this wrong, it should be ENOMEM 14 == ERROR_OUTOFMEMORY).

These errno numbers of the second kind are compatible with Unix error 
codes, not with Win32 error codes.  The socket ones were recycled just 
because Microsoft defined them to 10000 + the Unix error code, so it 
simplifies set_winsock_errno (I think I had even done WSAGetLastError () 
- 10000 in the first version but Bruno didn't like that).

Paolo