| Message ID | 20110106211327.GF21099@hall.aurel32.net |
|---|---|
| State | New |
| Headers | show |
On Thu, Jan 6, 2011 at 9:13 PM, Aurelien Jarno <aurelien@aurel32.net> wrote: > On Thu, Jan 06, 2011 at 07:45:01PM +0000, Blue Swirl wrote: >> There are a few variables which appear uninitialized to GCC 4.6.0: > > It's due to my commit 92d675d1c1f23f3617e24b63c825074a1d1da44b > >> CC i386-softmmu/cirrus_vga.o >> /src/qemu/hw/cirrus_vga.c: In function 'cirrus_bitblt_start': >> /src/qemu/hw/cirrus_vga.c:678: warning: 'depth' may be used >> uninitialized in this function >> /src/qemu/hw/cirrus_vga.c:678: note: 'depth' was declared here >> /src/qemu/hw/cirrus_vga.c:677: warning: 'dx' may be used uninitialized >> in this function >> /src/qemu/hw/cirrus_vga.c:677: note: 'dx' was declared here >> /src/qemu/hw/cirrus_vga.c:676: warning: 'sx' may be used uninitialized >> in this function >> /src/qemu/hw/cirrus_vga.c:676: note: 'sx' was declared here >> /src/qemu/hw/cirrus_vga.c:676: warning: 'sy' may be used uninitialized >> in this function >> /src/qemu/hw/cirrus_vga.c:676: note: 'sy' was declared here >> /src/qemu/hw/cirrus_vga.c:677: warning: 'dy' may be used uninitialized >> in this function >> /src/qemu/hw/cirrus_vga.c:677: note: 'dy' was declared here >> >> I don't think they are, since the variable use is conditional to >> notify variable: >> if (notify) >> qemu_console_copy(s->vga.ds, >> sx, sy, dx, dy, >> s->cirrus_blt_width / depth, >> s->cirrus_blt_height); > > Strangely neither GCC 4.4 nor GCC 4.5 trigger such a warning, though > they are usually catching cases like that. Could it be a regression in > GCC 4.6, or do you think it's just that it wasn't detected in previous > versions? It also happens with GCC 4.2.1 but not with 4.3.2. > >> Perhaps the code could be rearranged to avoid the warnings? Otherwise >> we could add zero initializers. >> > > Rearranging the code doesn't seems easy, so we should probably go to > zero initializers, as in the patch below. > > From: Aurelien Jarno <aurelien@aurel32.net> > > cirrus: delete GCC 4.6 warnings > > Commit 92d675d1c1f23f3617e24b63c825074a1d1da44b triggered uninitialized > variables warning with GCC 4.6. Fix them by adding zero initializers. > > Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Acked-by: Blue Swirl <blauwirbel@gmail.com> > --- > hw/cirrus_vga.c | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/hw/cirrus_vga.c b/hw/cirrus_vga.c > index 833a2eb..75d1cc6 100644 > --- a/hw/cirrus_vga.c > +++ b/hw/cirrus_vga.c > @@ -673,9 +673,9 @@ static int cirrus_bitblt_videotovideo_patterncopy(CirrusVGAState * s) > > static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h) > { > - int sx, sy; > - int dx, dy; > - int depth; > + int sx = 0, sy = 0; > + int dx = 0, dy = 0; > + int depth = 0; > int notify = 0; > > /* make sure to only copy if it's a plain copy ROP */ > > -- > Aurelien Jarno GPG: 1024D/F1BCDB73 > aurelien@aurel32.net http://www.aurel32.net >
diff --git a/hw/cirrus_vga.c b/hw/cirrus_vga.c index 833a2eb..75d1cc6 100644 --- a/hw/cirrus_vga.c +++ b/hw/cirrus_vga.c @@ -673,9 +673,9 @@ static int cirrus_bitblt_videotovideo_patterncopy(CirrusVGAState * s) static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h) { - int sx, sy; - int dx, dy; - int depth; + int sx = 0, sy = 0; + int dx = 0, dy = 0; + int depth = 0; int notify = 0; /* make sure to only copy if it's a plain copy ROP */