[dpdk-dev,v3,13/17] gcc/arm: avoid alignment errors to break build

  There several issues with alignment when compiling for ARMv7.
They are not considered to be fatal (ARMv7 supports unaligned
access of 32b words), so we just leave them as warnings. They
should be solved later, however.

Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>
Signed-off-by: Vlastimil Kosar <kosar@rehivetech.com>
---
 mk/toolchain/gcc/rte.vars.mk | 6 ++++++
 1 file changed, 6 insertions(+)
  

On Tue, Oct 27, 2015 at 8:13 PM, Jan Viktorin <viktorin@rehivetech.com>
wrote:

> There several issues with alignment when compiling for ARMv7.
> They are not considered to be fatal (ARMv7 supports unaligned
> access of 32b words), so we just leave them as warnings. They
> should be solved later, however.
>
> Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>
> Signed-off-by: Vlastimil Kosar <kosar@rehivetech.com>
> ---
>  mk/toolchain/gcc/rte.vars.mk | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
> index 0f51c66..8f9c396 100644
> --- a/mk/toolchain/gcc/rte.vars.mk
> +++ b/mk/toolchain/gcc/rte.vars.mk
> @@ -77,6 +77,12 @@ WERROR_FLAGS += -Wcast-align -Wnested-externs
> -Wcast-qual
>  WERROR_FLAGS += -Wformat-nonliteral -Wformat-security
>  WERROR_FLAGS += -Wundef -Wwrite-strings
>
> +# There are many issues reported for ARMv7 architecture
> +# which are not necessarily fatal. Report as warnings.
> +ifeq ($(CONFIG_RTE_ARCH_ARMv7),y)
> +WERROR_FLAGS += -Wno-error
> +endif
> +
>

Can we disable only "known" problems ?

Something like :
WERROR_FLAGS += -Wno-error=cast-align
  

On Wed, 28 Oct 2015 13:16:24 +0100
David Marchand <david.marchand@6wind.com> wrote:

> On Tue, Oct 27, 2015 at 8:13 PM, Jan Viktorin <viktorin@rehivetech.com>
> wrote:
> 
> > There several issues with alignment when compiling for ARMv7.
> > They are not considered to be fatal (ARMv7 supports unaligned
> > access of 32b words), so we just leave them as warnings. They
> > should be solved later, however.
> >
> > Signed-off-by: Jan Viktorin <viktorin@rehivetech.com>
> > Signed-off-by: Vlastimil Kosar <kosar@rehivetech.com>
> > ---
> >  mk/toolchain/gcc/rte.vars.mk | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
> > index 0f51c66..8f9c396 100644
> > --- a/mk/toolchain/gcc/rte.vars.mk
> > +++ b/mk/toolchain/gcc/rte.vars.mk
> > @@ -77,6 +77,12 @@ WERROR_FLAGS += -Wcast-align -Wnested-externs
> > -Wcast-qual
> >  WERROR_FLAGS += -Wformat-nonliteral -Wformat-security
> >  WERROR_FLAGS += -Wundef -Wwrite-strings
> >
> > +# There are many issues reported for ARMv7 architecture
> > +# which are not necessarily fatal. Report as warnings.
> > +ifeq ($(CONFIG_RTE_ARCH_ARMv7),y)
> > +WERROR_FLAGS += -Wno-error
> > +endif
> > +
> >  
> 
> Can we disable only "known" problems ?
> 
> Something like :
> WERROR_FLAGS += -Wno-error=cast-align
> 
> 

Sure! That's better idea, I always forgot about this possibilities in
GCC...

Jan