host gcc 4.7 warning when generating defconfig

host gcc 4.7 warning when generating defconfig

[Vineet Gupta]

Hi,

We do cross compile builds for ARC Linux. To avoid the env var set, we have a
defconfig entry for CONFIG_CROSS_COMPILE.
This worked fine so far (host gcc 4.4 i.e.). When switched to a new host distro
(gcc 4.7), a defconfig build spews out the warning.

------------------->8--------------------------
mymake defconfig
gcc: error: unrecognized command line option '-marc600'
gcc: error: unrecognized command line option '-mA7'
gcc: error: unrecognized command line option '-mno-sdata'
gcc: error: unrecognized command line option '-mno-mpy'
*** Default configuration is based on 'fpga_defconfig'
#
# configuration written to .config
------------------->8--------------------------

While the following trivial fix seems to fix this, it seems that the spew is
coming due to LIBGCC definition line, which is strange to be called for defconfig
generation. Any thoughts ?

---------------->
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index 4232d4e..97e6c20 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -8,6 +8,10 @@
 
 UTS_MACHINE := arc
 
+ifeq ($(CROSS_COMPILE),)
+#CROSS_COMPILE := arc-elf32-
+endif
+
 KBUILD_DEFCONFIG := fpga_defconfig

Thx,
-Vineet

Re: host gcc 4.7 warning when generating defconfig

[Sam Ravnborg]

On Thu, Mar 21, 2013 at 12:20:21PM +0530, Vineet Gupta wrote:
> Hi,
> 
> We do cross compile builds for ARC Linux. To avoid the env var set, we have a
> defconfig entry for CONFIG_CROSS_COMPILE.
> This worked fine so far (host gcc 4.4 i.e.). When switched to a new host distro
> (gcc 4.7), a defconfig build spews out the warning.
> 
> ------------------->8--------------------------
> mymake defconfig
> gcc: error: unrecognized command line option '-marc600'
> gcc: error: unrecognized command line option '-mA7'
> gcc: error: unrecognized command line option '-mno-sdata'
> gcc: error: unrecognized command line option '-mno-mpy'
> *** Default configuration is based on 'fpga_defconfig'
> #
> # configuration written to .config
> ------------------->8--------------------------
> 
> While the following trivial fix seems to fix this, it seems that the spew is
> coming due to LIBGCC definition line, which is strange to be called for defconfig
> generation. Any thoughts ?
> 
> ---------------->
> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> index 4232d4e..97e6c20 100644
> --- a/arch/arc/Makefile
> +++ b/arch/arc/Makefile
> @@ -8,6 +8,10 @@
>  
>  UTS_MACHINE := arc
>  
> +ifeq ($(CROSS_COMPILE),)
> +#CROSS_COMPILE := arc-elf32-
> +endif
> +
>  KBUILD_DEFCONFIG := fpga_defconfig


You could try to use LIBGCC = $(shell ... for assignment.
Use "=" and not ":=".

Like this:

-LIBGCC := $(shell $(CC) $(ARC_LIBGCC) $(cflags-y) --print-libgcc-file-name)
+LIBGCC = $(shell $(CC) $(ARC_LIBGCC) $(cflags-y) --print-libgcc-file-name)

This would defer the evaluation until we actually reference the variable,
and thus I think it will not trigger for a defconfig build.

I could not reproduce the problem here so I am not sure this has any effect though...

	Sam

Re: host gcc 4.7 warning when generating defconfig

[Vineet Gupta]

Hi Sam,

On 04/01/2013 05:42 PM, Sam Ravnborg wrote:
> On Thu, Mar 21, 2013 at 12:20:21PM +0530, Vineet Gupta wrote:
>> Hi,
>>
>> We do cross compile builds for ARC Linux. To avoid the env var set, we have a
>> defconfig entry for CONFIG_CROSS_COMPILE.
>> This worked fine so far (host gcc 4.4 i.e.). When switched to a new host distro
>> (gcc 4.7), a defconfig build spews out the warning.
>>
>> ------------------->8--------------------------
>> mymake defconfig
>> gcc: error: unrecognized command line option '-marc600'
>> gcc: error: unrecognized command line option '-mA7'
>> gcc: error: unrecognized command line option '-mno-sdata'
>> gcc: error: unrecognized command line option '-mno-mpy'
>> *** Default configuration is based on 'fpga_defconfig'
>> #
>> # configuration written to .config
>> ------------------->8--------------------------
>>
>> While the following trivial fix seems to fix this, it seems that the spew is
>> coming due to LIBGCC definition line, which is strange to be called for defconfig
>> generation. Any thoughts ?
>>
>> ---------------->
>> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
>> index 4232d4e..97e6c20 100644
>> --- a/arch/arc/Makefile
>> +++ b/arch/arc/Makefile
>> @@ -8,6 +8,10 @@
>>  
>>  UTS_MACHINE := arc
>>  
>> +ifeq ($(CROSS_COMPILE),)
>> +#CROSS_COMPILE := arc-elf32-
>> +endif
>> +
>>  KBUILD_DEFCONFIG := fpga_defconfig
> 
> 
> You could try to use LIBGCC = $(shell ... for assignment.
> Use "=" and not ":=".
> 
> Like this:
> 
> -LIBGCC := $(shell $(CC) $(ARC_LIBGCC) $(cflags-y) --print-libgcc-file-name)
> +LIBGCC = $(shell $(CC) $(ARC_LIBGCC) $(cflags-y) --print-libgcc-file-name)
> 
> This would defer the evaluation until we actually reference the variable,
> and thus I think it will not trigger for a defconfig build.
> 
> I could not reproduce the problem here so I am not sure this has any effect though...

Indeed the defconfig is fixed with your suggestion.
However make ARCH=arc {clean,distclean} still show the same spew !

Thx,
-Vineet