Re: [PATCH 2/2] kernel32: Implement a few more classes in GetFileInformationByHandleEx

[Martin Storsjö]

On Tue, 12 May 2015, Andrew Eikum wrote:
> On Tue, May 12, 2015 at 05:17:44PM +0300, Martin Storsjö wrote:
> > > @@ -919,8 +919,24 @@ BOOL WINAPI GetFileInformationByHandleEx( HANDLE handle, FILE_INFO_BY_HANDLE_CLA
> > >        SetLastError( ERROR_CALL_NOT_IMPLEMENTED );
> > >        return FALSE;
> > > - case FileBasicInfo:
> > > - case FileStandardInfo:
> > > case FileNameInfo:
> > > -
> > >    status = NtQueryInformationFile( handle, &io, info, size, FileNameInformation );
> > > -
> > >    switch (class) {
> > > -
> > >    case FileBasicInfo:
> > > -
> > >        nt_class = FileBasicInformation;
> > > -
> > >        break;
> > > -
> > >    case FileStandardInfo:
> > > -
> > >        nt_class = FileStandardInformation;
> > > -
> > >        break;
> > > -
> > >    case FileNameInfo:
> > > -
> > >        nt_class = FileNameInformation;
> > > -
> > >        break;
> > > -
> > >    default:
> > > -
> > >        assert(0);
> > > -
> > >        break;
>
> The default case seems unnecessary, since it's impossible.

At least my gcc (4.7) doesn't realize it, and complains about all the 
unhandled cases in the switch.
> But, this whole double-switch thing strikes me as ugly. Another option
> would be to call NtQueryInformationFile with the correct argument in
> each case, then break and do the 'if(status!=SUCCESS)' stuff outside
> of the switch statement.  That would eliminate the code duplication
> with the NtQueryDirectoryFile error checking, too.

That sounds like a good idea.
> > Is there anything concrete that needs to be fixed in this (and the
> > other kernel32 patch in the same thread) to be acceptable?
>
> Tests would help for both patches.

Yep, although I don't off-hand have any good idea of a meaningful test for 
GetSystemTimePreciseAsFileTime.

// Martin