On 29.06.2016 01:43, Michael Roth wrote: > As of e4650c81, we do w32 builds with -Werror enabled. Unfortunately > for cases where we enable VSS support in qemu-ga, we still have > warnings generated by VSS includes that ship as part of the Microsoft > VSS SDK. > > We can selectively address a number of these warnings using > > #pragma GCC diagnostic ignored ... > > but at least one of these: > > warning: ‘typedef’ was ignored in this declaration > > resulting from declarations of the form: > > typedef struct Blah { ... }; > > does not provide a specific command-line/pragma option to disable > warnings of the sort. > > To allow VSS builds to succeed, the next-best option is disabling > these warnings on a per-file basis. pragmas like #pragma GCC > system_header can be used to declare subsequent includes/declarations > as being exempt from normal warnings, but this must be done within > a header file. > > Since we don't control the VSS SDK, we'd need to rely on a > intermediate header include to accomplish this, and > since different objects in the VSS link target rely on different > headers from the VSS SDK, this would become somewhat of a rat's nest > (though not totally unmanageable). > > The next step up in granularity is just marking the entire VSS > SDK include path as system headers via -isystem. This is a bit more > heavy-handed, but since this SDK hasn't changed since 2005, there's > likely little to be gained from selectively disabling warnings > anyway, so we implement that approach here. > > This fixes the -Werror failures in both the configure test and the > qga build due to shared reliance on $vss_win32_include. For the > same reason, this also enforces a new dependency on -isystem support > in the C/C++ compiler when building QGA with VSS enabled.
Did we ever support any non-GCC-based compiler for building QGA? I don't think so, but in the worst case, we could later add a check whether the compiler supports that parameter, too... Anyway, I think your patch is a nice and clean way to deal with the error messages from these headers, so: Reviewed-by: Thomas Huth <th...@redhat.com>