Re: Conflict between sparse and commit cafa0010cd51f ("Raise the minimum required gcc version to 4.6")

[Christophe LEROY]

Le 10/09/2018 Ã 15:56, Luc Van Oostenryck a ÃcritÂ:
> On Mon, Sep 10, 2018 at 01:19:07PM +0000, Christophe Leroy wrote:
> > On 09/10/2018 11:34 AM, Luc Van Oostenryck wrote:
> > > On Mon, Sep 10, 2018 at 09:56:33AM +0000, Christophe Leroy wrote:
> > > > # export REAL_CC=ppc-linux-gcc
> > > > # make CHECK="cgcc -target=ppc -D_CALL_ELF=2 -D__GCC__=5
> > > > -D__GCC_MINOR__=4" C=2 arch/powerpc/kernel/process.o
> > > > scripts/kconfig/conf  --syncconfig Kconfig
> > > > #
> > > > # configuration written to .config
> > > > #
> > > >     UPD     include/config/kernel.release
> > > >     UPD     include/generated/utsrelease.h
> > > >     CC      kernel/bounds.s
> > > >     CC      arch/powerpc/kernel/asm-offsets.s
> > > >     CALL    scripts/checksyscalls.sh
> > > >     CHECK   scripts/mod/empty.c
> > > > Can't exec "/bin/sh": Argument list too long at /usr/local/bin/cgcc line 86.
> > > > make[2]: *** [scripts/mod/empty.o] Error 1
> > > > make[1]: *** [scripts/mod] Error 2
> > > > make: *** [scripts] Error 2
> > >
> > > OK. Clearly nobody has ever used it so :(
> > > There is an infinite loop because cgcc use the env var CHECK
> > > to call sparse while kbuild use CHECK to call cgcc here.
> > >
> > > The following seems to work here.
> > > $ export REAL_CC=ppc-linux-gcc
> > > $ make CHECK="CHECK=sparse cgcc -target=ppc ...
> >
> > Not yet ...
> >
> > [root@pc16082vm linux-powerpc]# export REAL_CC=ppc-linux-gcc
> > [root@pc16082vm linux-powerpc]# make CHECK="CHECK=sparse cgcc
> > -target=ppc -D_CALL_ELF=2 -D__GNUC__=5 -D__GNUC_MINOR__=4" C=2
> > arch/powerpc/kernel/process.o
> >    CALL    scripts/checksyscalls.sh
> >    CHECK   scripts/mod/empty.c
> > <command-line>:0:0: warning: "__STDC__" redefined
> > <built-in>: note: this is the location of the previous definition
> > /opt/cldk-1.4.0/lib/gcc/ppc-linux/5.4.0/../../../../ppc-linux/lib/crt1.o:(.rodata+0x4):
> > undefined reference to `main'
> > collect2: error: ld returned 1 exit status
> > make[2]: *** [scripts/mod/empty.o] Error 1
> > make[1]: *** [scripts/mod] Error 2
> > make: *** [scripts] Error 2
>
> OK. Using cgcc creates more problems that it solves and this file
> scripts/mod/empty.c is weird.
> Dropping cgcc and simply giving the GCC version to sparse works for
> me here (the needed defines are given by arch/powerpc/Makefile) but
> for sure I don't have the same environment as you have:
>    $ make CHECK="sparse -D__GNUC__=5 -D__GNUC_MINOR__=4" ...

This time it works, thanks for your help.

Should we find a may to automate that in the Makefile when CROSS_COMPILE 
is defined ?

> Bonne chance,

Merci

Christophe