[kvm-unit-tests PATCH 1/6] libcflat: add PRI(dux)32 format types

[Andrew Jones]

On Thu, Jan 12, 2017 at 05:18:25PM +0000, Alex Bennée wrote:
> 
> Andrew Jones <drjones at redhat.com> writes:
> 
> > On Thu, Jan 12, 2017 at 01:29:24PM +0100, Paolo Bonzini wrote:
> >>
> >>
> >> On 11/01/2017 17:28, Alex Bennée wrote:
> >> > So we can have portable formatting of uint32_t types. However there is
> >> > a catch. Different compilers can use legally subtly different types
> >> > though so we need to probe the compiler defined intdef.h first.
> >>
> >> Interesting, what platform has long uint32_t?  I thought the issue was
> >> whether 64-bit is long or "long long".
> >>
> >> Paolo
> >>
> >> > Signed-off-by: Alex Bennée <alex.bennee at linaro.org>
> >> > ---
> >> >  Makefile       |  1 +
> >> >  configure      | 13 +++++++++++++
> >> >  lib/libcflat.h |  9 +++++++++
> >> >  3 files changed, 23 insertions(+)
> >> >
> >> > diff --git a/Makefile b/Makefile
> >> > index a32333b..9822d9a 100644
> >> > --- a/Makefile
> >> > +++ b/Makefile
> >> > @@ -55,6 +55,7 @@ CFLAGS += $(fomit_frame_pointer)
> >> >  CFLAGS += $(fno_stack_protector)
> >> >  CFLAGS += $(fno_stack_protector_all)
> >> >  CFLAGS += $(wno_frame_address)
> >> > +CFLAGS += $(if $(U32_LONG_FMT),-D__U32_LONG_FMT__,)
> >> >
> >> >  CXXFLAGS += $(CFLAGS)
> >> >
> >> > diff --git a/configure b/configure
> >> > index 995c8fa..127868c 100755
> >> > --- a/configure
> >> > +++ b/configure
> >> > @@ -109,6 +109,18 @@ if [ -f $testdir/run ]; then
> >> >      ln -fs $testdir/run $testdir-run
> >> >  fi
> >> >
> >> > +# check if uint32_t needs a long format modifier
> >> > +cat << EOF > lib_test.c
> >> > +#include <inttypes.h>
> >> > +EOF
> >> > +
> >> > +$cross_prefix$cc lib_test.c -E | grep "typedef" | grep "long" | grep "uint32_t" &> /dev/null
> >
> > This won't work with cross compilers that don't have inttypes.h in their
> > path (like mine). How about something like
> 
> Hmm good point, in my case inttypes.h came from the libnewlib-dev package.
> 
> >
> >  cat << EOF > lib_test.c
> >  __UINT32_TYPE__
> >  EOF
> >  u32_long="`aarch64-linux-gnu-gcc lib_test.c -E | awk '/unsigned/ && $2 == "long"'`"
> 
> Hmm it is not clear from the docs if this is a GCCism. If it is do we
> care? Also the docs do say:

I think we're pretty bound to gcc already. I guess until somebody picks
up the effort to get clang, or whatever, compiling runnable
kvm-unit-tests, and commits to maintaining it, then I wouldn't worry too
much about it...

> 
> "Some of these macros may not be defined on particular systems if GCC does not provide a stdint.h header on those systems. "

We already expect stdint.h, we include it from libcflat.h.

> 
> > Although I feel there should be a compiler macro way to do this without
> > a need for configure/makefile trickery at all...
> 
> I did ask our toolchain bods. They started going on about potential
> solutions using _Generic but I fear that might be worse in this case!

Yikes :-)

drew

> 
> >
> > Thanks,
> > drew
> >
> >
> >> > +exit=$?
> >> > +if [ $exit -eq 0 ]; then
> >> > +    u32_long=true
> >> > +fi
> >> > +rm -f lib_test.c
> >> > +
> >> >  # check for dependent 32 bit libraries
> >> >  if [ "$arch" != "arm" ]; then
> >> >  cat << EOF > lib_test.c
> >> > @@ -155,4 +167,5 @@ TEST_DIR=$testdir
> >> >  FIRMWARE=$firmware
> >> >  ENDIAN=$endian
> >> >  PRETTY_PRINT_STACKS=$pretty_print_stacks
> >> > +U32_LONG_FMT=$u32_long
> >> >  EOF
> >> > diff --git a/lib/libcflat.h b/lib/libcflat.h
> >> > index 380395f..e80fc50 100644
> >> > --- a/lib/libcflat.h
> >> > +++ b/lib/libcflat.h
> >> > @@ -58,12 +58,21 @@ typedef _Bool		bool;
> >> >  #define true  1
> >> >
> >> >  #if __SIZEOF_LONG__ == 8
> >> > +#  define __PRI32_PREFIX
> >> >  #  define __PRI64_PREFIX	"l"
> >> >  #  define __PRIPTR_PREFIX	"l"
> >> >  #else
> >> > +#if defined(__U32_LONG_FMT__)
> >> > +#  define __PRI32_PREFIX        "l"
> >> > +#else
> >> > +#  define __PRI32_PREFIX
> >> > +#endif
> >> >  #  define __PRI64_PREFIX	"ll"
> >> >  #  define __PRIPTR_PREFIX
> >> >  #endif
> >> > +#define PRId32  __PRI32_PREFIX	"d"
> >> > +#define PRIu32  __PRI32_PREFIX	"u"
> >> > +#define PRIx32  __PRI32_PREFIX	"x"
> >> >  #define PRId64  __PRI64_PREFIX	"d"
> >> >  #define PRIu64  __PRI64_PREFIX	"u"
> >> >  #define PRIx64  __PRI64_PREFIX	"x"
> >> >
> >> --
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> 
> 
> --
> Alex Bennée