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

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

[Christophe Leroy]

Since commit cafa0010cd51f ("Raise the minimum required gcc version to 
4.6"), sparse check fails as follows:

[root@pc16082vm linux-powerpc]# make C=2 arch/powerpc/kernel/process.o
   CALL    scripts/checksyscalls.sh
   CHECK   scripts/mod/empty.c
./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too 
old - please upgrade it.
   CHECK   arch/powerpc/kernel/process.c
./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too 
old - please upgrade it.


I have sparse version 0.5.2

What can be done to fix that ?

Christophe

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

[Christophe LEROY]

Cc linux-sparse@vger.kernel.org

Le 07/09/2018 à 14:22, Christophe Leroy a écrit :
> Since commit cafa0010cd51f ("Raise the minimum required gcc version to 
> 4.6"), sparse check fails as follows:
> 
> [root@pc16082vm linux-powerpc]# make C=2 arch/powerpc/kernel/process.o
>    CALL    scripts/checksyscalls.sh
>    CHECK   scripts/mod/empty.c
> ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too 
> old - please upgrade it.
>    CHECK   arch/powerpc/kernel/process.c
> ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too 
> old - please upgrade it.
> 
> 
> I have sparse version 0.5.2
> 
> What can be done to fix that ?
> 
> Christophe

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

[Nick Desaulniers]

On Fri, Sep 7, 2018 at 7:34 AM Christophe LEROY <christophe.leroy@c-s.fr> wrote:
>
> Cc linux-sparse@vger.kernel.org
>
> Le 07/09/2018 à 14:22, Christophe Leroy a écrit :
> > Since commit cafa0010cd51f ("Raise the minimum required gcc version to
> > 4.6"), sparse check fails as follows:
> >
> > [root@pc16082vm linux-powerpc]# make C=2 arch/powerpc/kernel/process.o
> >    CALL    scripts/checksyscalls.sh
> >    CHECK   scripts/mod/empty.c
> > ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
> > old - please upgrade it.
> >    CHECK   arch/powerpc/kernel/process.c
> > ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
> > old - please upgrade it.
> >
> >
> > I have sparse version 0.5.2
> >
> > What can be done to fix that ?
> >
> > Christophe

Oof, sorry Christophe.  Looks like that's the latest version of sparse:
https://sparse.wiki.kernel.org/index.php/Main_Page#News

I'm curious what sparse expands __GNUC__, __GNUC_MINOR__, and
__GNUC_PATCHLEVEL__ to?  Pre commit cafa0010cd51f, it MUST be
expanding them to something, otherwise you'd have seen the error then,
too.  The previous check was GCC < 3.3, now it's GCC < 4.6.

We could change the check to:

-#if GCC_VERSION < 40600
+#if GCC_VERSION < 40600 && !defined(__CHECKER__)

But it would be good to know what those sub macros that compose
GCC_VERSION evaluate to in sparse; maybe they can be upgraded in
Sparse unless they're matching __builtin_*() compatability?
-- 
Thanks,
~Nick Desaulniers

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

[Luc Van Oostenryck]

On Fri, Sep 07, 2018 at 10:22:56AM -0700, Nick Desaulniers wrote:
> On Fri, Sep 7, 2018 at 7:34 AM Christophe LEROY <christophe.leroy@c-s.fr> wrote:
> >
> > Cc linux-sparse@vger.kernel.org
> >
> > Le 07/09/2018 à 14:22, Christophe Leroy a écrit :
> > > Since commit cafa0010cd51f ("Raise the minimum required gcc version to
> > > 4.6"), sparse check fails as follows:
> > >
> > > [root@pc16082vm linux-powerpc]# make C=2 arch/powerpc/kernel/process.o
> > >    CALL    scripts/checksyscalls.sh
> > >    CHECK   scripts/mod/empty.c
> > > ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
> > > old - please upgrade it.
> > >    CHECK   arch/powerpc/kernel/process.c
> > > ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
> > > old - please upgrade it.
> > >
> > >
> > > I have sparse version 0.5.2
> > >
> > > What can be done to fix that ?
> > >
> > > Christophe
> 
> Oof, sorry Christophe.  Looks like that's the latest version of sparse:
> https://sparse.wiki.kernel.org/index.php/Main_Page#News
> 
> I'm curious what sparse expands __GNUC__, __GNUC_MINOR__, and
> __GNUC_PATCHLEVEL__ to?  Pre commit cafa0010cd51f, it MUST be
> expanding them to something, otherwise you'd have seen the error then,
> too.  The previous check was GCC < 3.3, now it's GCC < 4.6.

Sparse expand these macros to the same version than the compiler used
to compile GCC. I find a bit strange though to have sparse v0.5.2 but
using an old compiler.
 
Also, it's worth to look at what is said in this email:
  https://lore.kernel.org/lkml/CA+55aFzYEnZR2GZLR-DwpONjMNYGYoDy+6AWLCVNayWiaZuqoA@mail.gmail.com/


-- Luc

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

[Nick Desaulniers]

On Fri, Sep 7, 2018 at 11:13 AM Luc Van Oostenryck
<luc.vanoostenryck@gmail.com> wrote:
>
> On Fri, Sep 07, 2018 at 10:22:56AM -0700, Nick Desaulniers wrote:
> > On Fri, Sep 7, 2018 at 7:34 AM Christophe LEROY <christophe.leroy@c-s.fr> wrote:
> > >
> > > Cc linux-sparse@vger.kernel.org
> > >
> > > Le 07/09/2018 à 14:22, Christophe Leroy a écrit :
> > > > Since commit cafa0010cd51f ("Raise the minimum required gcc version to
> > > > 4.6"), sparse check fails as follows:
> > > >
> > > > [root@pc16082vm linux-powerpc]# make C=2 arch/powerpc/kernel/process.o
> > > >    CALL    scripts/checksyscalls.sh
> > > >    CHECK   scripts/mod/empty.c
> > > > ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
> > > > old - please upgrade it.
> > > >    CHECK   arch/powerpc/kernel/process.c
> > > > ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
> > > > old - please upgrade it.
> > > >
> > > >
> > > > I have sparse version 0.5.2
> > > >
> > > > What can be done to fix that ?
> > > >
> > > > Christophe
> >
> > Oof, sorry Christophe.  Looks like that's the latest version of sparse:
> > https://sparse.wiki.kernel.org/index.php/Main_Page#News
> >
> > I'm curious what sparse expands __GNUC__, __GNUC_MINOR__, and
> > __GNUC_PATCHLEVEL__ to?  Pre commit cafa0010cd51f, it MUST be
> > expanding them to something, otherwise you'd have seen the error then,
> > too.  The previous check was GCC < 3.3, now it's GCC < 4.6.
>
> Sparse expand these macros to the same version than the compiler used
> to compile GCC. I find a bit strange though to have sparse v0.5.2 but
> using an old compiler.

So Christophe must have a version of gcc < 4.6 installed somewhere?
Does sparse use `cc`? If so, Christophe, does your `ls -l $(which cc)`
point to an old version of gcc maybe?

>
> Also, it's worth to look at what is said in this email:
>   https://lore.kernel.org/lkml/CA+55aFzYEnZR2GZLR-DwpONjMNYGYoDy+6AWLCVNayWiaZuqoA@mail.gmail.com/
>
>
> -- Luc



-- 
Thanks,
~Nick Desaulniers

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

[Luc Van Oostenryck]

On Fri, Sep 07, 2018 at 11:19:43AM -0700, Nick Desaulniers wrote:
> On Fri, Sep 7, 2018 at 11:13 AM Luc Van Oostenryck wrote:
> >
> > Sparse expand these macros to the same version than the compiler used
> > to compile GCC. I find a bit strange though to have sparse v0.5.2 but
> > using an old compiler.
> 
> So Christophe must have a version of gcc < 4.6 installed somewhere?

It looks so.

> Does sparse use `cc`?

By default sparse use gcc (this can be overriden by using CC=...).

-- Luc

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

[Christophe LEROY]

Le 07/09/2018 à 20:19, Nick Desaulniers a écrit :
> On Fri, Sep 7, 2018 at 11:13 AM Luc Van Oostenryck
> <luc.vanoostenryck@gmail.com> wrote:
>>
>> On Fri, Sep 07, 2018 at 10:22:56AM -0700, Nick Desaulniers wrote:
>>> On Fri, Sep 7, 2018 at 7:34 AM Christophe LEROY <christophe.leroy@c-s.fr> wrote:
>>>>
>>>> Cc linux-sparse@vger.kernel.org
>>>>
>>>> Le 07/09/2018 à 14:22, Christophe Leroy a écrit :
>>>>> Since commit cafa0010cd51f ("Raise the minimum required gcc version to
>>>>> 4.6"), sparse check fails as follows:
>>>>>
>>>>> [root@pc16082vm linux-powerpc]# make C=2 arch/powerpc/kernel/process.o
>>>>>     CALL    scripts/checksyscalls.sh
>>>>>     CHECK   scripts/mod/empty.c
>>>>> ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
>>>>> old - please upgrade it.
>>>>>     CHECK   arch/powerpc/kernel/process.c
>>>>> ./include/linux/compiler-gcc.h:14:3: error: Sorry, your compiler is too
>>>>> old - please upgrade it.
>>>>>
>>>>>
>>>>> I have sparse version 0.5.2
>>>>>
>>>>> What can be done to fix that ?
>>>>>
>>>>> Christophe
>>>
>>> Oof, sorry Christophe.  Looks like that's the latest version of sparse:
>>> https://sparse.wiki.kernel.org/index.php/Main_Page#News
>>>
>>> I'm curious what sparse expands __GNUC__, __GNUC_MINOR__, and
>>> __GNUC_PATCHLEVEL__ to?  Pre commit cafa0010cd51f, it MUST be
>>> expanding them to something, otherwise you'd have seen the error then,
>>> too.  The previous check was GCC < 3.3, now it's GCC < 4.6.
>>
>> Sparse expand these macros to the same version than the compiler used
>> to compile GCC. I find a bit strange though to have sparse v0.5.2 but
>> using an old compiler.
> 
> So Christophe must have a version of gcc < 4.6 installed somewhere?
> Does sparse use `cc`? If so, Christophe, does your `ls -l $(which cc)`
> point to an old version of gcc maybe?

Indeed it looks like sparse expand these macros to the version of the 
compiler it was compiled with.

I'm building kernels for a powerpc platforms, with CROSS_COMPILE set to 
ppc-linux- and ppc-linux-gcc being version 5.4

However my build machine is a CentOS6 and the native gcc has version 
4.4.7, so sparse expands that version.

Is there a way to get sparse in line with my cross compiler version and 
not with the local native version ?

Christophe

> 
>>
>> Also, it's worth to look at what is said in this email:
>>    https://lore.kernel.org/lkml/CA+55aFzYEnZR2GZLR-DwpONjMNYGYoDy+6AWLCVNayWiaZuqoA@mail.gmail.com/
>>
>>
>> -- Luc
> 
> 
> 

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

[Luc Van Oostenryck]

On Mon, Sep 10, 2018 at 08:49:07AM +0200, Christophe LEROY wrote:
> Le 07/09/2018 à 20:19, Nick Desaulniers a écrit :
> > On Fri, Sep 7, 2018 at 11:13 AM Luc Van Oostenryck wrote:
> > > 
> > > Sparse expand these macros to the same version than the compiler used
> > > to compile GCC. I find a bit strange though to have sparse v0.5.2 but
> > > using an old compiler.
> > 
> > So Christophe must have a version of gcc < 4.6 installed somewhere?
> > Does sparse use `cc`? If so, Christophe, does your `ls -l $(which cc)`
> > point to an old version of gcc maybe?
> 
> Indeed it looks like sparse expand these macros to the version of
> the compiler it was compiled with.
> 
> I'm building kernels for a powerpc platforms, with CROSS_COMPILE set
> to ppc-linux- and ppc-linux-gcc being version 5.4
> 
> However my build machine is a CentOS6 and the native gcc has version
> 4.4.7, so sparse expands that version.

OK, I see.
 
> Is there a way to get sparse in line with my cross compiler version
> and not with the local native version ?

When cross-compiling, there is also things like the machine word-size
and the endianness to take in account (they also default to the
native compiler used to compile sparse itself) as well as a few
defines (like __PPC64__). To be in line with your cross-compiler
you can use to the wrapper 'cgcc' (installed with sparse) and call
it, for example, like this:
	$ export REAL_CC=ppc-linux-gcc
	$ cgcc -target=ppcc64 -D_CALL_ELF=2 -D__GCC__=5 -D__GCC_MINOR__=4 ...
or, since this is for the kernel:
	$ export REAL_CC=ppc-linux-gcc
	$ make CHECK='cgcc -target=ppcc64 ...


I think this should solve it. Do not hesitate to report any
difficulties you may encounter.

-- Luc

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

[Christophe Leroy]

On 09/10/2018 09:28 AM, Luc Van Oostenryck wrote:
> On Mon, Sep 10, 2018 at 08:49:07AM +0200, Christophe LEROY wrote:
>> Le 07/09/2018 à 20:19, Nick Desaulniers a écrit :
>>> On Fri, Sep 7, 2018 at 11:13 AM Luc Van Oostenryck wrote:
>>>>
>>>> Sparse expand these macros to the same version than the compiler used
>>>> to compile GCC. I find a bit strange though to have sparse v0.5.2 but
>>>> using an old compiler.
>>>
>>> So Christophe must have a version of gcc < 4.6 installed somewhere?
>>> Does sparse use `cc`? If so, Christophe, does your `ls -l $(which cc)`
>>> point to an old version of gcc maybe?
>>
>> Indeed it looks like sparse expand these macros to the version of
>> the compiler it was compiled with.
>>
>> I'm building kernels for a powerpc platforms, with CROSS_COMPILE set
>> to ppc-linux- and ppc-linux-gcc being version 5.4
>>
>> However my build machine is a CentOS6 and the native gcc has version
>> 4.4.7, so sparse expands that version.
> 
> OK, I see.
>   
>> Is there a way to get sparse in line with my cross compiler version
>> and not with the local native version ?
> 
> When cross-compiling, there is also things like the machine word-size
> and the endianness to take in account (they also default to the
> native compiler used to compile sparse itself) as well as a few
> defines (like __PPC64__). To be in line with your cross-compiler
> you can use to the wrapper 'cgcc' (installed with sparse) and call
> it, for example, like this:
> 	$ export REAL_CC=ppc-linux-gcc
> 	$ cgcc -target=ppcc64 -D_CALL_ELF=2 -D__GCC__=5 -D__GCC_MINOR__=4 ...
> or, since this is for the kernel:
> 	$ export REAL_CC=ppc-linux-gcc
> 	$ make CHECK='cgcc -target=ppcc64 ...
> 
> 
> I think this should solve it. Do not hesitate to report any
> difficulties you may encounter.

# 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

Christophe

> 
> -- Luc
> 

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

[Luc Van Oostenryck]

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 ...

It's a bit kludgy, I admit.

-- Luc

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

[Christophe Leroy]

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

Christophe

> 
> It's a bit kludgy, I admit.
> 
> -- Luc
> 

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

[Luc Van Oostenryck]

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" ...

Bonne chance,
-- Luc

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

[Christophe LEROY]

Le 10/09/2018 à 15:56, Luc Van Oostenryck a écrit :
> 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

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

[Luc Van Oostenryck]

On Mon, Sep 10, 2018 at 04:05:34PM +0200, Christophe LEROY wrote:
> 
> This time it works, thanks for your help.

You're welcome.
 
> Should we find a may to automate that in the Makefile when
> CROSS_COMPILE is defined ?

The situation here with an old gcc is really an oddity.
I was instead thinking to update sparse so that it repports a
GCC version of at least 4.6, maybe something even more recent.

But maybe, yes, kbuild could pass GCC_VERSION to sparse so
that both the compiler used and sparse will repport the same.
I'll see. The problem is not tied to cross-compilation, though,
just that sparse may be compiled with an older compiler.

-- Luc