Re: 4.98 fails to build with newer gcc

[Johan Hedberg <johan.hedberg@gmail.com>]

Hi,

On Fri, Jan 13, 2012, Siarhei Siamashka wrote:
> On Fri, Jan 13, 2012 at 3:10 PM, Bastien Nocera <hadess@hadess.net> wrote:
> > A few warnings:
> >
> > sbc/sbc.c:766:34: warning: always_inline function might not be inlinable [-Wattributes]
> > sbc/sbc.c:558:34: warning: always_inline function might not be inlinable [-Wattributes]
> > sbc/sbc.c:163:31: warning: always_inline function might not be inlinable [-Wattributes]
> 
> Looks like the new version of gcc requires both "inline" and
> "__attribute__((always_inline))" to be used in SBC_ALWAYS_INLINE
> according to [1].
> 
> > and an error
> >
> > sbc/sbc_primitives_mmx.c: In function 'sbc_calc_scalefactors_mmx':
> > sbc/sbc_primitives_mmx.c:294:4: warning: asm operand 2 probably doesn't match constraints [enabled by default]
> > sbc/sbc_primitives_mmx.c:294:4: error: impossible constraint in 'asm'
> 
> Here gcc 4.7 thinks that
> 				"i" ((char *) &sb_sample_f[1][0][0] -
> 					(char *) &sb_sample_f[0][0][0]),
> is an impossible constraint. According to [2], "i" means "An immediate
> integer operand (one with constant value) is allowed. This includes
> symbolic constants whose values will be known only at assembly time or
> later".
> Earlier versions of gcc could see that this expression is a compile
> time constant, but gcc 4.7 can't. As a workaround, "i" can be changed
> to "r" here. The downside is that this needs one more register for
> inline assembly and the number of available registers is really
> limited for 32-bit x86 systems. As a test, it is possible to try "gcc
> -O2 -mmmx -c -m32 -fno-omit-frame-pointer -fPIC sbc_primitives_mmx.c".
> Both "-fno-omit-frame-pointer" and "-fPIC" options reduce the number
> of available registers.

So is someone going to send a patch for this? I think we should try to
have it fixed before doing the next BlueZ release.

Johan