On Tue, Jan 31, 2017 at 06:00:13PM +0000, Peter Maydell wrote: > On 31 January 2017 at 17:40, Markus Armbruster <arm...@redhat.com> wrote: > > Peter Maydell <peter.mayd...@linaro.org> writes: > > > >> We already require gcc 4.1 or newer (for the atomic > >> support), so the fallback codepaths for older gcc > >> versions than that are now dead code and we can > >> just delete them. > >> > >> NB: clang reports itself as gcc 4.2 (regardless of > >> clang version), so clang won't be using the fallbacks > >> either. > >> > >> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > >> --- > >> For compatibility with clang we should probably try to avoid > >> using QEMU_GNUC_PREREQ() and instead have something in > >> compiler.h that abstracts away whether the test for "does > >> the compiler support feature foo" is via a GCC version > >> check or a clang __has_feature or whatever. > > > > Yes, testing for feature is better than testing a version. > > > > This patch reduces use of QEMU_GNUC_PREREQ roughly by half. Good. > > > >> > >> > >> include/qemu/compiler.h | 8 --- > >> include/qemu/host-utils.h | 121 > >> ---------------------------------------------- > >> tcg/arm/tcg-target.h | 7 --- > >> 3 files changed, 136 deletions(-) > >> > >> diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h > >> index 157698b..fc12e49 100644 > >> --- a/include/qemu/compiler.h > >> +++ b/include/qemu/compiler.h > >> @@ -24,17 +24,9 @@ > >> > >> #define QEMU_NORETURN __attribute__ ((__noreturn__)) > >> > >> -#if QEMU_GNUC_PREREQ(3, 4) > >> #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result)) > >> -#else > >> -#define QEMU_WARN_UNUSED_RESULT > >> -#endif > > > > Should we inline this macro? > > We have attributes which we wrap in QEMU_ macros already > even though they always expand to the same thing: > QEMU_NORETURN and QEMU_ALIGNED. I'm happy to leave these > to follow that pattern. (If you wanted to send a patch > series that uninlined all of those then I wouldn't hugely > object to it, but I think it touches enough files that it's > a separate thing from removing the #if guards that this > patch does.)
The other option is just to replace QEMU_WARN_UNUSED_RESULT with #define QEMU_WARN_UNUSED_RESULT G_GNUC_WARN_UNUSED_RESULT and convert code to use G_GNUC_WARN_UNUSED_RESULT directly until we can kill the QEMU specific define. There's no benefit to QEMU having its own defines that duplicate stuff already covered by our min required glib - G_GNUC_WARN_UNUSED_RESULT was added in 2.10 for example. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|
