Re: [Qemu-devel] [PATCH v3 03/46] configure: add support for --cross-cc-FOO

[Murilo Opsfelder Araujo <muriloo@linux.ibm.com>]

On Wed, May 16, 2018 at 04:18:56PM +0100, Alex Bennée wrote:
> 
> Murilo Opsfelder Araujo <muriloo@linux.ibm.com> writes:
> 
> > On 04/24/2018 12:23 PM, Alex Bennée wrote:
> >> This allows us to specify cross compilers for our guests. This is
> >> useful for building test images/programs. Currently we re-run the
> >> compile test for each target. I couldn't think of a way to cache the
> >> value for a given arch without getting messier configure code.
> >>
> >> The cross compiler for the guest is visible to each target as
> >> CROSS_CC_GUEST in config-target.mak.
> >>
> >> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> >>
> >> ---
> >> v3
> >>   - --cross-cc-*[!a-zA-Z0-9_-]*=*) error_exit...
> >>   - --cross-cc-*) cc_arch=${opt#--cross-cc-}; cc_arch=${cc_arch%%=*}
> >>   - add remaining target_compiler definitions
> >> ---
> >>  configure | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 79 insertions(+)
> >>
> >> diff --git a/configure b/configure
> >> index b0ae632ee4..caa838a0d0 100755
> >> --- a/configure
> >> +++ b/configure
> >> @@ -453,6 +453,13 @@ vxhs=""
> >>  libxml2=""
> >>  docker="no"
> >>
> >> +# cross compilers defaults, can be overridden with --cross-cc-ARCH
> >> +cross_cc_aarch64="aarch64-linux-gnu-gcc"
> >> +cross_cc_arm="arm-linux-gnueabihf-gcc"
> >> +cross_cc_powerpc="powerpc-linux-gnu-gcc"
> >
> > Do we need to have default values for all targets?
> >
> >> +
> >> +enabled_cross_compilers=""
> >> +
> >>  supported_cpu="no"
> >>  supported_os="no"
> >>  bogus_os="no"
> >> @@ -483,6 +490,11 @@ for opt do
> >>    ;;
> >>    --disable-debug-info) debug_info="no"
> >>    ;;
> >> +  --cross-cc-*[!a-zA-Z0-9_-]*=*) error_exit "Passed bad --cross-cc-FOO option"
> >> +  ;;
> >> +  --cross-cc-*) cc_arch=${opt#--cross-cc-}; cc_arch=${cc_arch%%=*}
> >> +                eval "cross_cc_${cc_arch}=\$optarg"
> >> +  ;;
> >
> > Do we need to verify if a valid --cross-cc-FOO was passed, in case of a
> > typo?
> 
> How so? We do attempt to build with these options later.

Hi, Alex.

User can mistakenly pass, for example, --cross-cc-ppc64el= instead of the
expected --cross-cc-ppc64le=. I was wondering if we need to validate this kind
of input (inexistent $cross_cc_* variable) and consider --cross-cc-ppc64el= an
invalid option, in this example.

By the way, are you updating the --help text explaining these new --cross-cc-*
options?

-- 
Murilo