[Clfs-dev] GCC Host Requirement Issue

[William Harrington]

On Aug 12, 2013, at 8:58 AM, Martin Ward wrote:

> On 12/08/13 06:07, William Harrington wrote:
>> Greetings devs,
>>
>> We have a slight problem in gcc temp system:
>>
>> g++ -c   -g -O2 -DIN_GCC   -fno-exceptions -fno-rtti -fasynchronous- 
>> unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual - 
>> Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic- 
>> macros -Wno-overlength-strings -DHAVE_CONFIG_H -DGENERATOR_FILE -I.  
>> -Ibuild -I../../gcc-4.8.1/gcc -I../../gcc-4.8.1/gcc/build -I../../ 
>> gcc-4.8.1/gcc/../include -I../../gcc-4.8.1/gcc/../libcpp/include -I/ 
>> cross-tools/include -I/cross-tools/include -I/cross-tools/include - 
>> I../../gcc-4.8.1/gcc/../libdecnumber -I../../gcc-4.8.1/gcc/../ 
>> libdecnumber/dpd -I../libdecnumber -I../../gcc-4.8.1/gcc/../ 
>> libbacktrace -DCLOOG_INT_GMP -I/cross-tools/include -I/cross-tools/ 
>> include  \
>>                -o build/genconstants.o ../../gcc-4.8.1/gcc/ 
>> genconstants.c
>> cc1plus: error: unrecognized command line option "-Wno-narrowing"
>> cc1plus: error: unrecognized command line option "-Wno-overlength- 
>> strings"
>>
>> The host compiler is used to create some host build tools for the  
>> gcc build.
>>
>> Thus, it'll run g++ which will be the host's gcc.
>>
>> I was using the updated lfs livecd I recently put linux 3.10.5  
>> onto, and it seems moving to gcc-4.8.1 we have Wno error checking  
>> going bad.
>>
>> The following dialect options are only available starting with gcc  
>> 4.7:
>>
>> -Wno-narrowing  and -Wno-overlength-strings
>>
>>
>> This is going to cause some problems with hosts using GCC < 4.7.
>>
>> In config/warnings.m4 there is this change that is already in gcc  
>> 4.8.1:
>>
>> for real_option in $1; do
>>  # Do the check with the no- prefix removed since gcc silently
>>  # accepts any -Wno-* option on purpose
>>  case $real_option in
>> -    -Wno-*) option=-W`expr $real_option : '-Wno-\(.*\)'` ;;
>> +   -Wno-*) option=-W`expr x$real_option : 'x-Wno-\(.*\)'` ;;
>>    *) option=$real_option ;;
>>  esac
>>
>> I tried the old Wno line but it didn't help.
>>
>> Any ideas how we will get past this?
>>
>> We can remove -Wno-narrowing and -Wno-overlength-strings from gcc/ 
>> Makefile
>>
>> Upping the host system requirements to gcc 4.7 is a bit extreme.
>>
>> Sincerely,
>>
>> WIlliam Harrington
>> _______________________________________________
>> Clfs-dev mailing list
>> Clfs-dev at lists.cross-lfs.org
>> http://lists.cross-lfs.org/listinfo.cgi/clfs-dev-cross-lfs.org
>>
> Hmm just run through two builds, because i forgot the specs path  
> when compiling the final gcc and never ran into that
>
> I do remember seeing the line but is was as a  warning, rather than  
> and error, how about having
>
> |--disable-werror added?|
>
>
> martin

It was supposed to be fixed by now but it isn't. If the host compiler  
does not support Wno-narrowing or Wno-overlength-strings then the  
build will fail. In my case, I'm using the updated livecd, which uses  
GCC-4.1.2 and meets our host system requirements.

I found this which fixes the problem.

https://github.com/openembedded/oe-core/blob/master/meta/recipes-devtools/gcc/gcc-4.8/0038-gcc-4.8-build-args.patch

It looks we are going to need this or see if it is applied upstream.  
It is going to be an issue.

Sincerely,

William Harrington